US2869861A - Automatic door operator - Google Patents

Description

Jan. 20, 1959 M. CARLSON 2,869,861

AUTOMATIC DOOR OPERATOR Filed April 15, 1957 5 Sheets-Sheet 1 FIG. l.

INVENTOR: MARTIN CARLSON zw hviwu ATT'YS Jan. 20, 1959 CARLSON AUTOMATIC DOOR OPERATOR Filed April 15, 1957 5 Sheets-Sheet 2 f FIG. 4

MARTIN CARLSON BY j flfwwhv. View ATT'YS Jan. 20, 1959 M. c Lso 2,869,861

AUTOMATIC DOOR OPERATOR Filed April 15, 1957 5 Sheets-Sheet 5 INVENTOR: MARTIN CARLSON ATT'YS FIG.5

Jan. 20, 1959 M. c R so 2,869,861

AUTOMATIC DOOR OPERATOR Filed April 15, 1957 FIG. 6

INVENTOR: MARTIN CARLSON 5 Sheets-Sheet 4 Jan. 20, 1959 M. CARLSON AUTOMATIC DOOR OPERATOR 5 Sheets-Sheet 5 Filed April 15, 1957 INVENTOR. MARTIN CARLSON BY ATT'YS nite Stat This invention relates to an automatic door operator, and more particularly to an automatic door opening and closing apparatus having a break-away safety feature incorporated therein. The door operator of this invention has utility in conjunction with doors hung for pivotal movement about a generally vertical axis.

The trend in automatic door operators isto provide units that may be completely concealed beneath the floor surface adjacent the door controlled thereby so as to avoid the presence of dangerous and unsightly obstructions thereabout. Where such concealed door operator units are provided, it is desirable to have small and compact arrangements with simplified control circuit connections thereto, but at the same time to have a unit of sufficient power or capacity so as to operate the door with ease and thereby minimize breakdown problems which would arise if the unit were less powerful and, therefore, overloaded. Further, since door operators are usually employed in public buildings, it is advantageous to equip the same with a safety break-away device so that the door controlled thereby can be opened manually in the event of failure of the device itself or of the electric power supplying the control circuits thereof.

It is, accordingly, an object of this invention to provide an automatic door operator having the desirable and advantageous characteristics set forth above. Another object of the invention is in the provision of an automatic door opener in which the operating mechanism is cornpact whereby it is readily concealed beneath the floor in a 2 minimum of space, but irrespective of its reduced size is a powerful unit adequate-to manipulate a door with facility. Still another object is that of providing an automatic door operator mechanism, wherein the door pivot is' connected to a drive pinion through a crank arm of compound curvature (generally S-shape) which permits reduction in the size of the mechanism, and which provides a progressively increasing mechanical advantage through the final arc of travel of a door in the movement thereof to open position. a 7

Yet another object of the invention isthat of providing an automatic door operator equipped. with means for both opening and closing a door, andin which an eccentricaliy mounted drive pinion is supported for bodily movement in relation to both the door-opening and doorclosing drive gears in mesh therewith so as to progressively and incrementally change the torque or force relationship therebetween as a door is swung through its arc of movement, and thereby maintain a substantially uniform rate of travel of the door throughout the entire arc of movement thereof-the S-shaped crank, however, causing a somewhat slower rate of movement at the start and end of both the door-opening and door-closing cycles.

Yet a further object is to equip an automaticdoor operator with a safety break-away permitting the door controlled thereby to be swung manually, in either direction, to an open position if arrangement as described which is characterized'by havthe mechanism is shut downer in' operative. Still a furtherobjec't is to provide a break-awa y 2,869,861 Patented Jan. 20, 1959 ing multiple positions,the first or normal position being one wherein substantial force is required to release the door from the control of the operator and permit relatively free movement of the door through an arc of predetermined length-for example, about 45 whereat the break-away again resists free movement of the door but subsequently releases it if a further force of much lesser magnitude is applied to the door, thereby again permitting it to move relatively freely and into a full open position. Still a further object is that of providing abreak-away arrangement as described, wherein the operator and door are automatically rese't after a break-away action, either by returning the door to its closed position or by initiating a door-opening cycle. 7 p

An additional object of the invention isto provide an automatic door operator having an electro-hydraulic control and actuating circuit of improved character, comprising safety features that include among others an arrangement that permits relatively free manual movement of a door, apart from the break-away heretofore mentioned, whenever the operator is deenergized. Still another object is that of providing an interrelated electrical control and hydraulic power circuit, wherein a sequential operating cycle including the steps of opening and thereafter closing the door is established, and wherein the door after being opened, is maintained in such condition for a predetermined time before the subsequent automatic closing thereof. Additional objects and advantages of the invention will become apparent as the specification develops. Embodiments of the invention are illustrated in the accompanying drawings, in which- Figure l is a horizontal longitudinal sectional view of the operator mechanis'rnrFigure 2 is a vertical longitudinalsectio-nal view taken along the line 2-2 of Figure 1; Figure3 is an enlarged broken top plan view of the operator mechanism, and in which the cover plate is broken away to show a modification'the'r'eof; Figure 4 is an enlarged, broken sectional view taken along the line ll-{-4- of Figure 3; Figure 5 is a schematic diagram of the electrical and hydraulic circuits for the operator mechanism shown'in Figures 1' through 4; Figure'o is a horizontal longitudinal sectional view of still a further modified form of operator mechanism; Figure 7 is a vertical sectional view taken generally along the line 7-7 of Figure 6; and Figure 8 is a schematic diagram of the electrical and hydraulic circuits for the operator mechanism illustrated in Figure 6.

Referring first to Figures 1 and 2, it will be seen that the operator mechanism is contained within an outer housing 10 that may be referred to as a cement case in thatwhen the operator is installed, the case lit) is ordinarily recessed within a concrete floor beneath the door. The cement case has upwardly extending side and end walls and is open at the top thereof. However, adjacent the upwardly extending end wall 11 of the case is an extension 12that affords space for a workmanto make connection between the mechanism within the cement case and the electric and hydraulic circuits which are customarily located remotely therefrom. For this purpose, the'rear' wall'may be provided with openings13'and 14 therethrough communicating the interior of the cement I case .with the interior of the extension 12.

Shown mounted within the interior of the cement case isv an inner casing or housing 15 having" upwardly extending' side walls 16 and 17 and end walls 18 and 19 formed integrally therewith and being of arcuate configuration.

As shown in Figure 2, the inner casing will be provided with a cover 20 to close the interior thereof, and the cover may be secured to the side walls by cap screws or other suitable fastening means; The inner casing 15 is equipped alongthe bottom wail thereof adjacent the end wall 18 with an upwardly rising boss 21 having a recess 22 centrally disposed therein, enlarged at its upper end to define an annular land or shoulder 23. Positioned within the enlarged end portion of the recess is a ball bearing assembly 24, the outer race of which is seated on the land 23. The inner race of the bearing receives the reduced end 25 of a spindle 26 which at its upper end (not shown) is adapted to be rigidly secured to a door structure, and it defines the pivotal axis thereof. That is to say, when the spindle 26 is pivoted, a door secured thereto is swung between open and closed positions.

The spindle 26 extends through the cover 20 and is supported for rotation therein within a bearing 27 contained within a bearing housing 28 threadedly received within an opening provided therefor in the cover. Preferably, a dirt seal 29, which may be in the form of an O-ring, surrounds the spindle 26 at the upper end of the bearing housing 28. Just beneath the cover 2%, the spindle 26 has an annular flange gear 36 equipped with teeth in mesh with corresponding teeth provided by a surrounding spindle gear flange 31. Thus, when the gear flange 31 is rotated, the spindle 26 is rotated.

Rotatably mounted on the spindle 26 beneath the flange gear 39 is a hub 32 constrained against longitudinal movement with respect to the spindle by a thrust bearing 33 and thrust washer 34 bearing thereagainst, which in turn are constrained against the bearing by a split collar 35 and retaining ring 36. Preferably formed integrally with the hub 32 and extending outwardly therefrom are a pair of spaced apart, parallel crank plates 37 and' 38. The crank plates 37 and 38 have extending therethrough at one point therealong a crank pin 39 that pivotally extends through one end of a crank 40. When the crank is operated, as will be described in detail hereinafter, the crank plates 37 and 38 are pivoted through an arc of predetermined length to similarly pivot the gear flange 31 (through connecting mechanism now to be described), and consequently the spindle 26.

It may be noted that the gear flange 31 is circular, but along one side thereof has an outwardly projecting arcuate segment 41 defining stops 42 and 43 at opposite ends thereof, which are adapted to engage the respective opposite ends 44 and 45 of an abutment seg ment 46 provided by the wall 18 of the inner casing 15. For convenience and interchangeability, the gear flange and casing in this respect are symmetrical and enable the mechanism 'to be adapted to doors that swing either in wardly or outwardly in the opening thereof. However, in the specific illustration, the stop 43 and abutment 45 therefor are ordinarily expected to since the gear flange 31 in normal operation of the mechanism will be pivoted between the position shown in Figure 1 to a position clockwise thereof wherein the stop 42 and abutment 44 are adjacent. This latter location will represent the open position of the spindle 26.

It is seen most clearly in Figure 2 that the crank plates 37 and 38 have a pin housing 47 extending therethrough that may be thought of as a break-away pin housing. The housing is hollow, but is provided with a lower end closure that affords a seat for a helical spring 48 that bears upwardly against a break-away pin 49 having a frusto-conical upper end that enters a cone-shaped recess 50 provided therefor in the gear flange 31. By referring to Figure 1, it will be apparent that three such breakaway pins and associated structure are provided and for identification they are designated with the same numerals but with the respective suflixes a and 11 added to the latter two, although each of these arrangements is identical. The coil springs 48 are relatively strong and urge the pins 49 upwardly into the recesses 50 therefor so as to afford a driving connection between the crank plates 37 and 38 and the gear flange 31. However, if a torque of sufficient magnitude is applied to the spindle 26 as, for example, by pushing hard against a'door seeured perform no function,

a door connected to e the spindle may be locked on the rod 66 by thereto, such torque will cam the break-away pins 49 from the recesses 50 if rotational movement of the crank plates 37 and 38 is resisted to permit the spindle 26 and a door secured thereto to rotate independently of the door operator mechanism.

It will be noted that break-away pins 49 and 49a are spaced from each other by an arc of approximately while the pins 49 and 49b are spaced apart by an arc of approximately 90. Therefore, the break-away feature has two positions-the first which is illustrated, wherein all of the break-away pins are seated within the gear flange, which of course will require a fairly large force to release them therefrom; and a second position, wherein following such an initial break away, the gear flange is rotated approximately 45 with respect to the crank plates 37 and 3S whereupon the break-away pin 49 will seat within the recess a to again establish a driving connection between the gear flange and crank plates. At this time, the pins 49a and 4% are disengaged. Now, if a further torque of much lesser magnitude is applied to the spindle 26, the pin 49 will be cammed from the recess to permit the gear flange 31 to be rotated through another arcuate distance of slightly less than 45 -that is, until the stop 42 engages the abutment 44.

Centrally disposed within the casing 15 and rising upwardly from the bottom wall thereof is a boss 51 having an opening 52 therein that receives the lower end of a pivot shaft 53, the upper end of which is correspondingly received within an opening 54 defined within a shaft support member 55 fixedly carried by the cover 29. A drive pinion 56 is fixedly mounted on a sleeve 57 rotatably supported by the shaft 53 by needle bearings 58 adjacent its lower end and needle bearings 59 adjacent its upper end. A spacer 60 may be carried by the shaft in interposed relation between the bearings 58 and 59 to maintain the separation thereof. Also fixedly secured to the sleeve 57 are a pair of spaced apart, parallel lugs or platters 61 and 62. It will be apparent that when the drive pinion 56 is rotated, the lugs 61 and 62 rotate therewith, and by means of a primary crank pin 63 which extends therethrough and is pivotally received by an end of the crnak arm 40, drive the crank arm and therefore rotate 26 through the mechanism heretofore described.

It will benoted that the crank arm 40 has a compound curvature and is generally S-shaped. The crank arm 40 is employed because it affords a positive drive and interconnection between the crank plates 37 and 38 and the crank lugs 61 and 62. The generally S-shaped configuration has been derived because it substantially reduces the space requirements of the operator mechanism, and fur ther, it affords a mechanical advantage that enables a powerful driving torque to be delivered to the crank plates whereby a heavy door carried by the spindle 26 is readily swung between open and closed positions.

A door is operated to open position by means of rotating the drive pinion 56 in a'counter-clockwise direction, as viewed in Figure 1, through a rack gear 64 in mesh with the pinion, and which is guided for longitudinal movement by a support bracket 65. The rack gear 64 is seen to comprise an end of a piston rod 66 which threadedly carries at its inner end a piston 67 which is reciprocable within a cylinder 68 having cylinder heads 69 and 70 at the opposite ends thereof. The piston 67 a set screw 71;, and in the form shown sealingly engages the wall of the cylinder 68 through an O-ring seal 72. For convenience, the cylinder head 70 may also be provided with an O-ring seal 73.

The piston 67 is reciprocated toward the left as seen in Figure l by supplying hydraulic pressure fluid thereagainst through a coupling or connector 74 which is mounted by means of a threaded portion 75 thereon within a bore or passage 76 formed therefor in the cylinder head casting 77, which may be bolted or otherwise secured to the inner case 15. intermediate the ends of the coupling is anarea oireduced diameter denoted with the numeral 78 which defines a channel 79 thereabout, and the central passage 80 through the connector communicates with the channel 79 through an aperture 81. The portion 'of the bore 7 6 about the channel 79 is sealed by means of the spaced O-rings 82 and 33 so that fluid entering the channel is forced to flow between the aperhim 81 and a flow passage 84 which communicates with the interior of the cylinder 68 through a laterally extending passage portion 85. The passages 84 and 85 at their point of junction have a needle valve 86 adjustably positioned therein to regulate the rate of flow of fluid through these passages. As is evident from Figure 1, the passage 84 is formed in the casting by drilling a bore therethrough, and the outer end of such bore is closed by a plug 87. The passage 85 is-similarly formed in the casting and is also plugged at its outer end.

The connector or coupling 74, and particularly the flow passage 86 therethrough, is in open communication with the interior of the cylinder 63, and fluid may flow therethrough past a check valve 88 which is adapted to sealingly engage a seat 98 therefor. It will be apparent from this construction that when the outer threaded end 91 of the coupling is connected to a fluid flow conduit, pressure fluid delivered thereby will flow freely through the passage 80 past the check valve 88 and into the cylinder 68 to drive the piston 67 in a counter-clockwise direction to rotate the gear flange 31 and spindle 26 in a clockwise direction. Some fluid, of course, will escape through the aperture 81, and will flow through the passage segments 84 and 85; but since they also communicate with the cylinder 68, such fluid will contribute to the pressure force applied to the piston.

When the piston is moved toward the right and into the position shown in Figure l, the check valve 88 will sealingly engage the seat 9% and prevent pressure fluid from flowing therepast. Yet, the fluid will flow through the passages 85 and 84 which by-pass the check valve. The needle valve 86 in controlling the rate of flow through the passages 85 and 84, will provide means for regulating the rate of return of the piston 67 and, therefore, the rate of closing movement of a door carried by the spindle 26.

Return movement of the piston 67-that is, movement of a door to closed position-may be eifectuated by various means; and in the specific structure shown in Figures 1 and 2, a positive return is provided by an elongated coil spring 92 coaxial with a return piston rod Q3 equipped at one end with a rack gear 94 in mesh with the drive pinion 56 and actuated for movement by a bracket 95. The coil spring 92 seats at one end on a spring seat member 96 rigidly provided by the rod 93, andat its other end it seats against the casting 77 which is equipped with an annular boss 97 to positively orient the spring with respect thereto. The rod 3 is actuated for movement in a cylinder 98 by means of a piston or cylinder stud 99 with which the rod is equipped. The cylinder 98 is provided with a threaded extension 101) which is threadedly received in the casting 77 to rigidly mount the cylinder with respect thereto. It will be apparent that the interior of the cylinder should communicate with atmosphere as, for example, through a passage in the extension 1% to afford free movement of the piston 9g therein.

As will be described in detail hereinafter with reference to Figure 5, the door operator form a functional cycle of opening a door, maintaining it in open position for a predetermined time, and then closing the door; and as a part of the control circuits that provide this functional cycle is a microswitch 101 that is mounted on a bracket 192 secured by cap screws 1193 to the cylinder head 69. The microswitch has theplunger thereot aligned with the upper crank lug 61 so as to be engaged by the elongated end portion 104 thereof when the lug" has rotated through approximately 180 from ,is eflective to perthe pump outlet '6 the position shown in Figure 1. 7 It is noted in Figure 2 that the lower lug 62 in being identical with the lug 61, also hasan elongated end portion1il5. The microswitch is electrically connected to leads 166 and 1.07 that extend, respectively, to nylon pin jacks 108 and 16% therefor in the end wall 19 of the inner casing.

The power circuits comprising both the electrical and hydraulic circuitry for energizing the mechanism shown in Figures 1 and 2, is illustrated in Figure 5 and reference will now be made to that figure. The prime mover or power means comprises an electric motor 111) which drives a pump 111 having an intake 112 communicating with a reservoir 113. As is conventional, the pump also communicates with the reservoir through a bypass 114 having a pressure relief valve 115 therein. The hydraulic system comprises a closed circuit, and therefore the reservoir has an inlet 116 that may be provided with a filter 117.

The pump discharges through an outlet 118 having a check valve 119 therein and a flow conduit 12% connects with the power cylinder 68, and more the coupling or connector 74 heretofore The check valve 119'permits the flow of fluid in the direction of the arrow through the outlet 11% and prevents return flow therethrough. The flow conduit 12% adjacent the outer end thereof is connected through a short passage segment 121 to a solenoid controlled valve 122 having a plunger 123 equipped at its lower end with a valve 124 adapted to close the passage 121 to prevent the flow of fluid therethrough. The plunger 123 and consequently the valve 124, are biased upwardly by a coil spring 125 so that when the energizing coils 126 of the solenoid are not energized, the conduit 121 is open to permit the flow of fluid therethrough.

A laterally extending conduit 127 communicates with the valve chamber downstream of the valve 124, and arranged therewith is a needle valve 123 that is adjustable to regulate the rate of flow through the conduit 127. Beyond the valve 128, the conduit 127 communicates with the inlet 116 of the reservoir, and it is seen that this inlet is also in open communication with the flow conduit 12% through a check valve 129 that permits the flow of fluid therethrough to the conduit 12% but prevents flow in the opposite direction.

The motor 119 is seen to be connected to a source of alternating current through leads 131i and 131-the first of which is connected directly to such power source, while the lead 131 is adapted to be connected to such power source through the switch or contacts 132 of a solenoid or relay 133, and through a fuse 134 in series with the contacts. Connected across the power source through an additional fuse 135 is the primary winding 136 of a transformer 137 having a secondary winding 138 that feeds into a rectifier designated in general with the numeral 139. In the specific illustration, the rectifier comprises a full-wave bridge rectifier network having a rectifier tube in each leg thereof. The rectifiers may be germanium cells, and for identification are designated with the numerals 14d through 143. Connected across the output of the rectifier bridge is a capacitor 144.

The coils 126 of the solenoid valve 122 are connected across the output of the rectifier 139 through leads and 146. The lead 146 has interposed therein the switch contacts 147 of a solenoid 143. It will be seen that the energizing coil 14d of the solenoid 133 is serially connected by the switch contacts 147 to one side of the rectifier or filter output, and to the other side of the rectifier through microswitch 101, whereby the solenoid 133 is energized only when both the microswitch 101 is closed and the solenoid 148 is energized. The solenoid 133 may be considered a motor control solenoid, for the operation of the motor 110is controlled thereby. Similarly, the solenoid 148 may be considered the valve control solenoid, for when it is energized the valve 124- is closed.

The energizing coil 15% of the valve control solenoid particularly with described.

148 is connected to the negative side of a battery 151 through lead 152. The other side of the energizing coil is connected through lead 153 to the collector 154- of a transistor 155. The battery 151 provides the source of.

noid 164 having an energizing coil 165, one side of which is connected to the negative terminal of the hattery through lead 166, and the other side of which is connected through lead 167 to the collector 163 of the transistor 156. The base 169 of this transistor is connected to the negative side of the battery through fixed resistor 170 and potentiometer 171.

A main control switch 172 is connected directly between the base 162- and positive terminal of the battery 151, and this main control switch may take various forms. For example, it may be a handle mounted on a door controlled by the automatic operator, it may be a foot treadle located adjacent such door, or it may be a photoelectric cell as indicated by the specific illustration of Figure 5. To further specify the function of the photoelectric cell switching arrangement, a reflector-equipped light source 172a is illustrated in conjunction therewith. The beam of light directed thereby to the cell 172, will be interrupted when a person approaches the entrance side of the door equipped therewith.

Operation The operation of the circuits is as follows: Initially, the solenoid switch contacts 132, 147 and 163 are all open with the result that the solenoid valve 122 is deenergized whereby its valve 124 permits flow of iuid from the cylinder 68 to the reservoir 113. The microswitch 191 is closed and the main control switch 172 is in its normal condition. This then is the condition of the circuits when the return spring 92 is rotating the drive pinion 56 (by moving the rack gear 94 toward the left as seen in Figure 1), whereby the spindle 26 is rotated so as to close a door carried thereby, and the piston 67 at the same time is being moved toward the position thereof shown in Figure 1.

When the main control element 172 is actuated that is, there is an interruption in the light beam directed theretoward which is followed by a termination of the current flow therethrough and therefore through the resistor 17% and potentiometer 171, thus permitting the transistor 156 to conductcurrent will flow through the coil 165 of the solenoid 164 to close the solenoid contacts 163, whereby current will flow through the energizing coil of the solenoid 148 to cause closing of the contacts 147. This in turn results in energization of the solenoid 133 to close contacts 132, whereby the circuit 135-131 is completed and the motor 111') is energized to rotate the pump 111. Hydraulic fluid will then be forced past the check valve 119, through the conduit 12!) and into the cylinder 68 to force the piston 67 toward the left. Such action will rotate the drive pinion 56 in a counterclockwise direction as seen in Figure 1. As heretofore explained, such movement of the drive pinion will rotate the spindle 26 in a clockwise direction to open a door carried thereby.

This condition will be maintained until the extended end 104 of the crank lug 61 trips the microswitch 1111, whereupon the motor control solenoid 133 is deenergized to open the contacts 132 and deenergize the motor 115. However, the door will remain open and the circuits remain in the condition described with the solenoids 148 and 164 still energized for so long as the main control element 172 is actuated. The door cannot of course gusset be closed at this time because the energized solenoid 148 maintains the solenoid valve 122 in an energized condition, whereby the return path for the hydraulic fluid to the reservoir 113 is closed.

As soon as the control element 172 is returned to its normal condition, the solenoid 164 is deenergized thereby opening its contacts 163. Still, the solenoid 148 is not immediately deenergized because the capacitor which was discharged when the contacts 163 were closed now charges, maintaining a continued current flow through the solenoid coil 150. The time necessary for charge will depend upon the value of the capacitor, and more particularly upon the resistance-capacitance time con stant in the base circuit of the transistor 155. This time constant can be adjusted by means of the potentiometer 162. When the capacitor is charged sufficiently, the solenoid 148 will be deenergized whereupon the spring 125 will urge the solenoid valve plunger 123 upwardly to open the return circuit to the reservoir 113.

At this time, the spring 92 is effective to rotate the spindle to door-closing position and to return the power piston 67 to its initial position. The rate of return is determined by adjustment of the needle valves 86 and 128, but when the return is accomplished the circuit is conditioned for another cycle of operation. The potentiometer 171 is provided for adjusting the value of the voltage drop thereacross, whereby the normal potential on the base of the transistor 156 is adjustable to limit current flow therethrough to a value such that the solenoid 164 in its normal state is deenergized.

It may be noted that the circuits may be reactuated before the door is returned to full closed position, and

if this occurs, the circuits operate just as heretofore described for the initially described starting condition is attained just as soon as the end 104 of the crank lug 61 has been rotated from engagement with the plunger of the rnicroswitch 101.

Modifications A. modification of the mechanism is illustrated in Figures 3 and 4, and is concerned only with the drive pinion assembly. Since a considerable number of the parts are identical to those heretofore described, the same numerals will be applied thereto in describing this modification except that each will be primed.

in this form of the structure, the pivot shaft 53' is pressed into aligned openings provided therefor in the spaced arms 173 and 174 of a pivotal mounting support designated generally with the numeral 175. The arms are formed integrally with a sleeve 176 comprising a part of mounting support which is pivotally mounted on a generally vertical axle or shaft 177 supported at opposite ends by the members 178 and 179 carried, respectively, by the bottom wall of the inner casing 15 and by the cover 26' therefor. In the manner heretofore explained, the drive pinion 56 is secured to a sleeve 57' pivotally supported on bearings 58' and 59'. rigidly secured to the sleeve, crank arm 40' by the It will be noted by pinion 56 is eccentrically mounted on the pivot shaft 53 so that when the drive pinion is rotated in a counter clockwise direction, the axis of rotation thereof (which is defined by and is coincident with the pivot shaft 53') will tend to move incrementally and progressively closer to the longitudinal axis of the rack gear 64' and away from the axis of the rack gear the pivot shaft 53 is carried by the pivotal support mounting 175, the shaft (and therefore the pivot axis ofthe drive pinion which is defined thereby) shift its location as the pinion is rotated.

and are connected to the primary crank pin 63.

The advantage of having an eccentrically mounted drive pinion shiftable bodily between the rack gears 64? and 9,4.

to progressively change the distance of the rotational axis the shaft 53' by the The crank lugs 61 and 62' are referring to Figure 3 that the drivev 94, and vice versa. Since? can and does so of the rack gear 94'.

thereof from these gears, is to change the force applied first by the drive rack 64' to the drive pinion, and secondly to alter the force transferred throughthe drive pinion from the rack gear 64 to the rack gear 94. In further description of this, consider first the position of the mechanism as illustrated in Figures 3 and 4, at which time a door carried by the spindle 26 is closed.

When the door is to be opened, the inertia thereof must first be overcome so that initia'ily a relatively large force must be imparted thereto. 3 Such a force is' delivered to the drive pinion 56 by the rack gear 9 because the effective lever arm through which this force is applied is the distance from the longitudinal axis of the shaft 53 to the mid-position of the meshed teeth of thedrive pinion and rack gear 64'. It will be noted that,"as shown in Figure 3, this distance is somewhat greater than the radius of the drive pinion. Once the starting inertia is overcome, however, less force is necessary to' maintain continued movement of the door'throu'gh the first part of its arc of travel, and it will be noted that as the pinion rotates in the counter-clockwise direction, the effective lever arm at first becomes progressively smaller.

On the other hand, since the resistive force exerted by the spring 92, increases progressively as it is compressed (that is, the spring is a conventional Hooks Law type of spring rather than a constant force spring), it therefore requires increasingly greater forces to cornpress it to its full extent. Such a progressive increase in the force applied to the rack gear 94 is afforded, im-

mediately after the door has moved through the first small arc of'its travel, by incrementally increasingthe length of the effective lever arm through which the force is applied-namely, the distance from the longitudinal axis of the shaft 53 to the mid-position of the meshed teeth The rate of movement of the door is slowed somewhat as it approaches both the full open and full closed positions to prevent slamming.

A further modification of the structure is illustrated in I and constitutes the use of a power cylin- Figures 6 and 7, der to return the mechanism and a door structure to closed position instead of the spring cylinder-that is, the coil spring 92 and associated structure heretofore described in detail with reference to Figures 1 and 2. It should be noted as heretoforeindicated, that various means can be employed for closing a door, and both the spring-type piston return and hydraulic power piston return now to be described are exemplifications thereof. It will be understood that a single double-acting piston/ cylinder combination could be used in the mechanism, and such are well known in the art. However, it is preferred to use two single-acting pistons for it enables a more compact unit to be provided.

For the most part, the components illustrated in Figure 6 are identical with those heretofore described, and as a distinguishing feature these numerals are double-primed.

It is seen in Figure 6 that coextensive and in side-byside relation with the power cylinder 68 for opening a door, is a power cylinder 180 having a piston 181 reciprocable therein and establishing a sealing relation with the walls of the cylinder through an O-ring 182. This piston is carried by the rod 93" which, as has been explained hereinbefore, is equipped with a rack gear94 which is effective to rotate the drive pinion '56" in a di-' rection to close a door. The cylinder 180 is closed at its inner end by a cylinder head 183, and at its other end by a cylinder head 1841.

Admission of hydraulic fluid under pressure to the cylinder 180 is afforded through a valve-equipped coupling identical in construction and function to the coupling 74 (74 in Figure 6), and for that reason it will not be further described, but for identification will be denoted with the numeral 185. Apas'sage 186 communicates with the casting bore that'moun'ts the c'onnector185 therein, and this passagetintersect's passage 18 7 which communicates with the cylinder lsfit'lrro'iighthe cylinder 10 head 184. A needle-type regulator valve 188 is provided at the junction'of the passages 186 and 187, and it serves to control the flow rate therethrough.

Asis shown most clearly in Figure 7, a pair of microswitches are provided in vertically disposed relation, and are secured to the bracket 1652". The uppermost microswitch 101" has its plunger aligned with the upper crank lug 61" so as to be actuated by the extended end 104 thereof; and similarly, the lowermost microswitch 189 has its plunger aligned with the crank arm 40" so as to be actuated thereby when the crank arm is in the position shown in Figure 6. Each of the microswitches will be connected by appropriated leads to pin jacks in the casing for connection to the power circuits about to be described.

It will be apparent that when the piston 67" is forced to the left by the application of pressure fluid thereagainst through the coupling 74 to open a door carried by the spindle 26", the piston 181 will be forced toward the right and such movement will expel any fluid in the cylinder through the passages 187 and 186. When the door is to be closed, pressure fluid will be supplied to the cylinder to urge the piston 181 thereof toward the left and into the position shown in Figure 6.

Referring now to Figure 8, it will be seen that a motor 190 is provided for driving apump 191. It is evident then that the motor and pump will be mechanically associated, as shown in Figure 5 for example, but for convenience they are separated in the schematic illustration of Figure 8. The pump 191 communicates through an inlet 192 with a reservoir 193, and has an outlet conduit 194- equipped with a check valve 195 therein; and beyond the check valve, the conduit opens into valve chambers defined by a pair of solenoid controlled valves 1% and 197. It is seen that the valve chambers within these solenoid valves have a return connection to the reservoir 193-through the respective flow conduits 198 and 199.

The solenoid valve 196 intermediate the inlet and outlet ports thereof, communicates with the cylinder 68" through a conduit 2% through coupling 74". In a similar manner, the solenoid valve 197 is connected by a conduit 201 to the connector 185 which feeds into the cylinder 189. A valve plunger 292 in the solenoid valve 196 is biased away from the inlet and toward the end of the conduit 198 by a coil spring 203, and the solenoid valve 197 has a valve plunger 2% biased toward closure relation with the end of the conduit 199 by a coil spring 205. For identification, the energizing coil of the solenoid valve 196 is designated with the numeral 206, and the energizing coil of the solenoid valve 197 is designated with the numeral 207.

Power for the m0tor'190 and for certain elements of the electric circuit is provided by an alternating current source, the leads of which are designated with the numerals 208 and 209. One side of the motor, is connected directly to the lead 299, and the opposite side of-the motor is connected to the lead 2118 through a fuse 210 and switch contacts 211 of a solenoid 212 having an energizing coil 213. Line voltage is also connected through afuse 214 to the primary winding 215 of a transformer 216 having a secondary winding 217, one side of whichis connected through lead 218 with the energizing coil 213 of the solenoid 212. The coil 213 is also connected through lead 219 with the microswitches 101" and 189 which are connected in parallel (and are opened by the respective pistons when moved to the end of their strokes), and are connected respectively to the switch contacts 220 and 221 of a solenoid 222 which has an energizing coil 223. It will be seen that the switch contacts 220 and 221 are oppositely oriented so that when one is closed, the other is open. v

The energizing coils 20d and 207 of the respective solenoid valves are connected'to the switch contacts 224 and 225 of the solenoid 222, and these pair contacts are also oppositely oriented so'that they are alternately opened aseasei or closed. The coils 206 and 207 are connected together, and thence to additional ,switchtcontacts226 also provided by the solenoid 222-the opposite side of the contacts 226 being connected to a lead 227 that will be referred to hereinafter. It may be noted that the common side of the paired switches 220, 221 and 224, 224 as well as one side of the energizing coil 223 return to the power supplythat is, the secondary winding 217 of the transformer-through a lead 228.

Three additional solenoids are provided, designated respectively 229, 230 and 231. The first of these has a pair of switch contacts 232 connected across the secondary winding of the power transformer through the energizing coil 223 of the solenoid 222, whereby that solenoid is energized only when the switch contacts 232 are closed. The energizing coil 233 of the solenoid 229 has one side thereof connected to the negative terminal of battery 234, and its other side connected to the collector element of a transistor 235. the emitter of which is connected to the positivetterrninal of the battery. The base of the transistor is connected through a capacitor 236 and serially connected resistor 237 and potentiometer 238, to the negative terminal of the battery. The capacitor 236 is shunted by the switch contacts 239 of the solenoid 230.

The energizing coil 240 of the solenoid 230 has one side thereof connected to lead 228, and the other side to the corresponding sides of switch contacts 241 and 242 which are controlled by the solenoid 231. The energizing coil 243 of the solenoid 231 has one side thereof connected to lead 228, and its other side connected to a safety control switch 244, and through that switch to one side of the secondary winding of the power transformer. A main control switch 245 has one side connected to the secondary winding of the power transformer, and its other side connected to the switch con tacts 241. It may be noted that the switch contacts 242 are also connected through lead 246 to the contacts 226 of solenoid 222.

The control switch 245 and safety switch 244 are the main actuating switches for the circuit, and may take varied forms as heretofore indicated. However, in the specific illustration the switches are preferably in the form of treadles-the switch 245 being the foot treadle on the entrance side of a door, and the safety switch 244 being a foot treadle on the exit side of the same door. Conventionally, such treadle switches are arranged in conjunction with a continuous mat that extends through a doorway and beneath the door controlled by the automatic operator mechanism.

As the circuit is shown in Figure 8, it corresponds to the position of the various mechanical elements illustrated in Figure 6, That is to say, the door is closed and the operator or control switch 245 and safety switch 244 are both open. The door will remain closed for fiuid is locked in the cylinder 180 since its flow through the conduit 281 to the reservoir 123 is prevented by the check valve 195, and also by the plunger valve 2G4 which is biased into closing relation with the conduit 199 by the coil spring 295. The solenoid 196 is normally energized so the plunger valve 262 thereof is in closure relation with the valve inlet and prevents the flow of fluid thereinto.

If the control circuit is deenergized as, for example, by 'an interruption in the supply of power thereto, the solenoid valve 196 will be deenergized whereupon the door can be manually'swung between open and closed positions, for the fluid in the cylinder 130 willsimply circulatethrough the conduit solenoid valves 197 and 1%and conduit 200. The rate of movement of the door at such time will depend upon the setting of theneedle valves 36" and 188. V I

When the door: is closed and the circuit is as shown in Figure 8, the safety switch 244 (if it is closed as by stepping on the foot treadle at the exit side of the door) will cause the solenoid 231 to be energized, thereby opening switch contacts 241 which break the circuit through the control or operator switch 245. Therefore, as long as someone is standing on the safety switch 244,- the closed door cannot be opened. If the safety switch 244 is open as shown, and the operator control switch 245 closed by the approach of someone toward the entrance side of the door, a circuit is established through the solenoid 230 whereby the switch contacts 239 thereof are closed, permitting the capacitor 236 to discharge, with the result that current flows through the transistor 235 to energize the solenoid 229.

Energization of the solenoid 229 closes the switch contacts 232 thereof whereupon the solenoid valve 196 is deenergized, permitting the flow of fluid from the pump to the cylinder 68", and the solenoid valve 127 is energized thereby opening the return path for the flow of fluid from the cylinder to the reservoir 193. At the same time, solenoid 212 will be energized through the microswitch 101", and the motor 192 will be actuated since the switch contacts 211 of the solenoid 212 will be closed. The pump now delivers fluid under pressure to the cylinder 68" to force the piston 67" thereof toward the left, the piston 131 of the cylinder 1% will be forced toward the right (through the heretofore described coaction of the rack gears 64", 24" and drive pinion 56"), and the door will be opened. The motor will be deenergized when the microswitch 101 is opened since the motor circuit cannot be maintained through the microswitch 189, although it will be closed, because the three-pole solenoid 222 is energized and the switch contacts 221 therefor open.

The door will remain open as long as the control switch 245 is closed for escape of fluid from the cylinder 68 is prevented by the deenergized solenoid valve 1%. Now, if the safety switch 244 is closed, which is a normal occurrence since the person passing through the door will move from the control switch 245 to the safety switch 244, the circuit will remain in the actuated state described, for at this time the safety switch, and the solenoid 231 controlled thereby, acts as a holding circuit, maintaining the solenoid 222 in an energized condition.

As soon as the safety switch 244 is opened, the solenoid 231 and consequently the solenoid 222 will be tie-- energized; but the motor circuit, after the lag resulting from the timing circuit, will now become energized be cause of the flow of current through the of the solenoid 212, the completion of the circuit therefor being provided through the microswitch The motor will be deenergized when the door is returned to its closed position and the microswitch 139 is opened, as shown in Figure 8. It will be appreciated that the cycle of operation described can now be again initiated, and it should be understood that if the control switch 245 is closed before the door can be returned to its fully closed position, the door-opening phase of the cycle Will commence at such time.

For further identification, the solenoid may be considered a motor control; the solenoid 222, sole noid valve control; the solenoid 236, the control for the operator switch 245; and the solenoid 221, the control for the safety switch 244. The solenoid 22? is in effect a control for the solenoid 222 since such solenoid 222 is energized thereby.

All forms of the invention described have a positive connection between the drive pinion and crank plates through the S-shaped crank arm which enables them to be compacted into a small space while affording immediate response to changes in the control circuits. Also, each form embodies the break-away safety arrangement heretofore described whereby if the mechanism should become locked or jammed in some manner, the door,

controlled thereby can be manually opened. Such opening can occur in either direction in that the same twostage break-away action is atforded irrespective of the energizing coil '13 direction in which-the spindle is rotated. While the opening movement of the dooris terminated upon deenergization of the motor, the stop 42 and abutment 44 can serve as a mechanical means for terminating opening movement of the door.

The S-shaped crank while initially providing a high torque transfer to the spindle 26 to overcome the inertia of the door thereon, will now swing the door rather slowly because the primary movement of the crank Will be in a rotational sense about the axis of the drive pinion. The same is true when the door is reaching its full open position. It will be recalled that the motor is stopped whenever the door has reached its full open position whereby the circuit is susceptible to utilization as a hold-open device, and such arrangement is readily accomplished for example'by putting a manually operable on-off switch in the control circuit, i. e., by a switch across the mat or control switch, for example.

It will be noted that the configuration of the crank and the connective arrangement thereof with the crank lugs and gear flange is such that the gear fiage rotates through an arc of about one-half the length of the arc traversed by the lugs in their rotative movement. That is to say, the crank lugs reciprocate through an arc of approximately 180, while at the same time the spindle and gear flange thereof reciprocate through only about 90. Also, it may be noted that when the crank lugs are in one of their determinate positions (that is, the position shown in Figure l which represents the closed condition of a door), one portion of the compound curvature of the crank is substantially concentric with the drive pinion and pivot shaft 53, whereby the center of its radius is substantially concident with theaxis of the shaft.

The described apparatus has the further advantage of a dry sump which facilitates handling thereof. Moreover, the hydraulic circuit functions on a relatively low pressure that need not exceed about 200 pounds per square inch. It may be noted that the construction of the cylinders and casting permit ready interchangeability of the spring return cylinder and hydraulic power return cylinder, and also the mechanisms for'opening and for closing a door may be interchangeably mounted within the cas ing so that the operator is quickly convertible for either right or left-hand doors.

The dual position break-awayhas the advantage of requiring a relatively large force application thereto in order to cause its break-away when a door is closed. It will be appreciated that when a door is fully closed, the greatest leverage will be transmitted therethrough to the spindle when a force is applied to the outer edge of the door. Thus, the initial large force requirement prevents unintended break-away action. However, when the door is partially opened to about 45, for example, the torque applied therethrough to the spindle when a force is applied to the outer edge of the door, is substantially less than when the door is fully closed for the effective lever arm hasbeen decreased (assuming that the force application at this time will not be normal to the plane of the door, as is the case ordinarily). Therefore, since the second break-away action requires a lesser force to initiate the same, its requirement are consequently in correspondence with the available manual force. Moreover, this same two-stage arrangement permitsready manual resetting of the door after break-away.

While in the foregoing specification embodiments of the invention have been set forth and described in considerable detail for purposes of illustration, it will be readily apparent to those skilled in the art that numerous changes may be made in those details without departing from the spirit and principles of the invention.

I claim:

1; In a door operator mechanism of the character de scribed, a casing, a drive gear rotatably, supported in said casing and adapted to be selectively ro-tatedin opposite directions, a splndle supported in said casing for rotationalmovementand being adapted to have a door secured thereto for defining the pivotal axis for opening and closing movement thereof, and a crank pivotally coupled at one end thereof to said drive gear and pivotally coupled at its other end to said spindle, said crank having a compound curvature of generally S-shape and its coupling to said drive gear and spindle being on opposite sides of a plane common to. the axes of the gear and spindle. I

2. In an automatic door operator structure of the character described, a casing, a crank lug supported in said casing for pivotal movement, means for pivoting said crank lug selectively in opposite directions between two determinate positions, a spindle adapted to carry a door for swinging movement between open and closed positions about the axis defined by the spindle, said spindle being mounted in said casing laterally of said crank lug for pivotal movement about an axis substantially parallel to that of the crank lug, and a crank pivotally connected adjacent one end thereof to said crank lug and pivotally coupled adjacent its other end to said spindle for pivoting the spindle in accordance-with the pivotal movement of the crank lug, said crank being otherwise unconnected to afford bodily movement thereof and also being of generally S-shape and connected to said crank lug so-that one portion of the S-shaped curvature .has a center radius generally coincident with the. pivotal axis of the crank lug when the lug is in one of its determinate positions.

3. In an automatic door operator functional to open and close a door controlled thereby, a casing, a drive pinion mounted in said casing for pivotal movement and being equipped with a crank lug constrained against relative-rotation withrespect thereto, power means for selectively rotating said drive pinion in opposite directions to pivot said crank lug between two determinate-positions, a spindle-rotatably supported by said casing laterally of said pinion, and with its axis of rotation substantially parallel to the axis of rotation thereof, a gear. carried by said spindle in driving relation therewith, said spindle being adapted to have a door secured thereto for swinging the same between openand closed positions, and a crank arm pivotally connected at one end thereof to said crank lug and pivotally connected adjacent the otherend thereof to said gear, said crank having a compound curvature defined by reversely directed arcuate segments such that pivotal movement of said crank lug through an are having its termini defined by the aforesaid determinate positions causes said spindleto rotate through a corresponding arc of approximately one-half of the length of the aforesaid arc.

In a mechanism of the character described for opening and closing doors supported for swinging movement about a generally vertical axis, a casing, a spindle pivotally supported by said casing and being adapted to carry such a' door and to define the pivotal axis thereof, said spindle being equipped with a gear flange, a flange gear circumjacent said gear flange and in mesh therewith, a pivot shaft mounted in said casing'laterally ofand in substantially parailei relation with said. spindle, a drive pinion rotatably supported by said shaft, a crank lug also pivotally supported by said shaftand fixedly coupled to said drive pinion for rotation therewith, power means for selectively rotating said drive pinion in opposite directions and having gears inmeshing relation therewith, and a generally S-shaped crank pivotally connected adjacent one end thereof to said crank lug and pivotally' coupled adjacent its other end to said gear flange whereby pivotal movement of said drive pinion in opposite directions is eifective to similarly rotate said spindle to selectively open and close a door carried thereby, said S-shaped crank being connected and coupled respectively to said crank lug andgear .flange on opposite sides. of .a plane common to the axes of said spindle and shaft and in an arrangement such that rotationof the crank lug 15 through an arc of substantially 180 is effective to rotate said spindle through an arc of substantially 90.

5. The structure of claim 4 in which a pair of crank lugs are provided in spaced apart, generally parallel relation, and in which a crank pin extending between said crank lugs pivotally connects said crank thereto.

6. The structure of claim 5 in which said crank is coupled to said gear flange by a break-away drive.

7. The structure of claim 6 in which said power means comprises a hydraulic power cylinder having a piston re ciprocable therein and equipped with a rod longitudinally movable through an end of the cylinder, and a rack gear carried by said rod and in mesh with said drive pinion, said hydraulic cylinder and the piston thereof being operative to rotate said drive pinion to swing a door carried by said spindle from closed to open position.

8. The structure of claim 7 in which said power means comprises also a return spring cylinder having a rodequipped piston reciprocable therein, a rack gear carried by said rod and in meshing relation with said drive pinion, and a coil spring coaxial with said rod and operative to bias the same in a direction to efiectuate a rotation of said drive pinion and of said spindle to move a door carried thereby from open to closed position.

9. In a door operator mechanism for positively opening and closing a door, a casing, a first rack gear for eifectuating opening movement of a door and being supported in said casing for reciprocable movement, a second rack gear for elfectuating closing movement of a door and being mounted in said casing in spaced apart,

substantially parallel relation with said first rack gear for reciprocable movement, power means for driving the respective rack gears, a drive pinion interposed between said rack gears and in meshing engagement therewith, a shaft rotatably supporting said drive pinion thereon, and movable support means for said shaft to afford bodily movement thereof between said rack gears, said drive pinion being eccentrically mounted on said shaft whereby rotation thereof oppositely changes the spacing between said shaft and the respective rack gears, said drive pinion being adapted to be connected to the support shaft of a door for rotating the same.

10. In a door operator mechanism, a casing, a spindle rotatably supported by said casing and being adapted to carry a door for swinging the same between open and closed positions, a pivot shaft, means for supporting said pivot shaft in said casing laterally of said spindle and for bodily movement, a drive pinion eccentrically mounted on said shaft for rotation with respect thereto, at

least one crank lug pivotally carried by said shaft in corresponding eccentricity with said drive pinion and being constrained against rotation with respect thereto, a crank pivotally connected at one end to said crank lug and at the other end thereof being coupled to said spindle, and a pair of power actuated, oppositely facing rack gears respectively meshing with said drive pinion along opposite sides thereof and being supported in said casing for reciprocatory movement along their respective longitudinal axes, rotation of said drive pinion being operative to progressively change the relative position thereof with respect to said rack gears and thereby effectuate a change in the driving force relation therewith.

11. The structure of claim 10 in which a hydraulic power cylinder is provided for actuating one of said rack gears, and in which a spring powered cylinder is provided for actuating the other of said rack gears, said drive pinion and shaft being related to said rack gears so that rotation of the drive pinion in the direction compressing said spring increases the distance between the axis of said shaft and the rack gear actuated by said spring powered cylinder so as to effectuate an increase in the force delivered to the spring actuated rack gear as the spring thereof is progressively compressed.

12. In a door operator mechanism having a spindle adapted to control the opening and closing movement of a door carried thereby, a flange drivingly carried by said spindle in coaxial relation therewith, said flange being provided along a face thereof with a plurality of recesses aligned along an are having its origin at the axis of said spindle, a crank plate rotatably carried by said spin dle in facing relation with said flange along the face thereof providing said recesses, a plurality of break-away pins movably carried by said crank plate for respective alignment with said recesses, resilient means for urging each of said crank pins into seating relation with the respective recesses therefor, and power means for rotating said crank plate to drivingly rotate said flange through said break-away pins, said pins being successively forced into retraction from said recesses when a rotative force of predetermined magnitude is applied to said flange and rotation of said crank plate is constrained whereby the flange is progressively'disengaged from the crank plate to afford relatively free rotational movement thereof.

13. The door operator mechanism of claim 12 in which said pins and the recesses therefor are arranged in spaced apart relation along an are having its center of radius substantially coincident with the rotational axis of said spindle, and wherein a pair of said pins and recesses are spaced by an arcuate distance substantially less than the arc of movement of said spindle whereby both of said pair of pins are in the recesses therefor at the initiation of a break-away action and only one of the pair is in a recess at a subsequent relative position of said flange and crank plate.

14. In a mechanism of the character described, a casing, a spin-dle equipped with a flange and being rotatably supported by said casing, a crank plate rotatably supported by said spindle in facing relation with said flange, and a plurality of arcuately spaced, spring biased breakaway pins movably carried by said crank plate and being biased toward said flange and being aligned along an arc having its center at the axis of said spindle, said flange being provided with a plurality of recesses therein, one for each of said break-away pins, and respectively alignable therewith for normally receiving the same therein,

whereby rotation of said crank plate causes rotation of said flange and spindle through the driving connection afforded by the break-away pins between said crank plate and flange, said break-away pins being releasable from said recesses when oppositely directed torque of suflicient magnitude is applied respectively to'said crank plate and flange-equipped spindle to unseat all of said pins from said recesses and reseat a lesser number thereof.

15. The apparatus of claim 14 in which said recesses are all generally conical in configuration, and in which said crank pins are generally frust-o-conical at the ends thereof receivable within said recesses. V

16. The mechanism of claim 14 in which at least three break-away pins are provided in spaced apart relation along an arc having its center coincident with the rotational axis of said spindle, one of said pins being spaced from the one adjacent thereto along one side by an arcuate distance of approximately one-half the spacing thereof from the pin adjacent thereto along its other side.

17. Apparatus according to claim 16 in which a pair of crank plates are provided, the second of which is also rotatably carried by said spindle in spaced parallel relation with the aforesaid crank plate, said break-away pins being movable relative to said pair of crank plates along lines substantially normal thereto. V

18. In an automatic dooroperator system of thechar- :acter described, a hydraulic cylinder having a piston re.- ciprocable therein adapted to be operatively arranged with a door spindle for rotating the same, a pump-equipped motor for supplying hydraulic fluid to said cylinder for moving said piston in one direction, a hydraulic circuit connectingsaid pump with said cylinder and being pro videdwith auni-directional flow valve therein to prevent the flow of fluid from said cylinderand to said pump, a return flow conduit having a solenoid-equipped valve therein operative to close said return flow circuit when the solenoid is energized, an electric circuit including interrelated relay means for simultaneously energizing said motor and said solenoid, switch means connected in said circuit for deenergizing said motor and being arranged for actuation when said piston is adjacent the end of the power stroke thereof, and operator switch means connected in said circuit for energizing said interrelated relay means to initiate a cycle of operation, said interrelated relay means also being operated to deenergize said solenoid-controlled valve subsequent to the actuation of said first mentioned switch means to aiford return of said piston to its initial position in said cylinder.

19. In a power system for an automatic door operator of the character described, a power cylinder and a return cylinder each equipped with a piston reciprocable therein and adapted to be operatively arranged with a door for respectively opening and closing the same, a motorequipped pump for supplying fluid under pressure to said cylinders, separate circuit means for connecting said pump with said cylinders, each of said circuit means having a solenoid-equipped valve therein, separate return circuits from each of said solenoid-equipped valves, said solenoid-equipped valves being biased to a position of closing relation with said return circuits and when the solenoids thereof are energized, being in closure relation with said separate circuit means, a pair of interrupter switches one for each of said cylinders, a main control switch, a safety switch, and circuit means including interrelated relays for energizing said motor and selectively energizing said solenoid-equipped valves, said power system being operative when said safety switch is open and said main control switch is actuated to energize said motor and solenoid-equipped valves such that fluid under pressure is supplied to said power cylinder to energize the power stroke of the piston thereof and to aiford a retu n path for the flow of fluid from said return cylinder, said power system being operative when said safety switch is closed and said main control switch is open to energize said motor and solenoid-equipped valves so as to supply fluid under pressure to said return cylinder to energize the power stroke of the piston thereof and to afford a return path for the flow of fluid from said power cylinder, said interrupter switches being operative respectively to terminate operation of said motor when the respective pistons have reached the end of the power strokes thereof.

20. In an automatic door operator mechanism, a casing, a spindle rotatably supported by said casing and being adapted to be secured to a door member, a drive pinion supported for rotation in said casing, a genera ly S-shaped crank drivingly coupled to said pinion, breakaway means arranged with said spindle and being coupled to said crank whereby rotation of the pinion is effective to rotate said spindle, and power cylinder means drivingly connected with said pinion for rotating the same, and a hydraulic and electric control circuit for operating said door operator mechanism, said circuit comprising pump means for supplying fluid under pressure to said power cylinder means, and comprising also electric control elements including a main operator switch all interrelated with said pump means and power cylinder means for controlling a cycle of operation of said mechanism, said crank being coupled to said break-away means and pinion on opposite sides of a plane common to the axes of said spindle and pinion and being contoured so that'rotation of said pinion through an arcuate distance effects rotation of said spindle through substantially one-half such arcuate distance.

21. In a door operator mechanism for positively opening and closing a door, a casing, a first and a second rack gear supported within said casing in spaced apart relation for reciprocable movement and being respectively operative to effect opening and closing movements of such door,

means for driving the respective gears, a drive pinion interposed between said rack gears for meshing engagement therewith, a shaft rotatably supporting said drive pinion thereon, and movable support means for said. shaft to afford bodily movement thereof between said rack gears, said drive pinion being eccentrically mounted on said shaft whereby rotation thereof oppositely changes the spacing between said shaft and the respective rack gears, said drive pinion being adapted to be connected to the support shaft of a door for rotating the same.

22. in an automatic door operator mechanism, a casing, a spindle rotatably supported by said casing and being adapted to be secured to a door member, a drive pinion supported for rotation in said casing, a generally S-shaped crank drivingly coupled to said pinion, break-away means arranged. with said spindle and being coupled to said crank whereby rotation of the pinion is effective to rotate said spindle, and power cylinder means drivingly connected with said pinion for rotating the same, and a hydraulic and electric control circuit for operating said door operator mechanism, said circuit comprising pump means for supplying fluid under pressure to said power cylinder means, and comprising also electric control elements including a main operator switch all interrelated with said pump means and power cylinder means for controlling a cycle of operation of said mechanism, said break-away means comprising a flange carried by said spindle and a crank plate connected with said crank and being oriented in spaced apart facing relation with said flange, said flange being provided with a plurality of recesses arranged in spaced apart relation along an arc having its center of radius substantially coincident with the rotational axis of said spindle, and a plurality of break-away pins carried by said crank plate for respective alignment with said recesses and being movable in directions normal to said flange, said pins being resiliently urged into seating relation Within said recesses, said pins and recesses being arranged in pairs spaced from each other by arcuate distances substantially less than the arc of movement of said spindle whereby all of the pins are in the recesses therefor at the initiation of a break-away action and only one of the pins is in a recess at a subsequent relative position of said flange and crank plate.

23. In a door operator mechanism having a spindle adapted to control the opening and closing movement of a door carried thereby, a radial flange drivingly carried by said spindle, said flange being provided along a face thereof with a plurality of arcuately spaced apart recesses, a crank plate rotatably carried by said spindle in facing relation with said flange along the face thereof having said recesses, a plurality of break-away pins movably carried by said crank plate for respective alignment with said recesses, resilient means for urging said crank pins into seating relation with said recesses, and power means for rotating said crank plate to drivingly rotate said flange by means of said break-away pins, a pair of said pins and recesses being spaced equally from the axis of the spindle and spaced apart an arcuate distance substantially less than the angular rotation of said spindle upon movement of said door to opened position whereby both of said pair of pins are normally seated in recesses therefor and at the initiation of a break-away action and only one of the pair is seated in a recess at a subsequent relative position of said flange and crank plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,134,981 Mikulasek Nov. 1, 1938 2,276,338 Potter et al Mar. 17, 1942 2,609,674 Groat Sept. 9, 1952 2,676,796 Meyer Holz Apr. 27, 1954 2,739,808 Carlson Mar. 27, 1956

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