US2882773A - Bolt holding wrench - Google Patents

Description

April 21, 1959 G. s. WING 2,882,773

BOLT HOLDING WRENCH Filed June 10, 1957 2 Sheets-Sheet 1 2 33 F/G. 4 ,F/GZZ [III //I/ INA/5N 709,

650/?65 6. WING April 21, 1959 G. s. WING BOLT HOLDING WRENCH 2 Sheets-Sheet 2 Filed June 10, 1957 F/G. 6 /42 /57 A58 INVENTOR, 650/?65 5. W/A/6 By w WA fi7'TORNEY United States Patent BOLT HOLDING WRENCH George S. Wing, Palos Verdes Estates, Calif., assignor to Iii-Shear Rivet Tool Company, Torrance, Calif., a corporation of California Application June 10, 1957, Serial No. 664,634

3 Claims. (Cl. 81-56) ice a shoulder 31 facing toward the passage 26. A coil spring 32 biases the drive gear away from the passage 26.

The drive gear 30 meshes with a pinion gear 33 which is journaled in needle bearings 36 in part 22 of the frame and needle bearings 35 in part 21 of the frame. The pinion gear has teeth 34 and 37 which are axially spaced from each other. The teeth 34 mesh with the teeth on the drive gear 30, while the teeth 37 mesh with teeth 38 on a socket drive shaft 39.

The socket drive shaft 39 is journaled in a passage 40 through part 21 of the frame in needle bearings 41 so as to be rotatable therein. The socket drive shaft has a Wrench passage 42 therethrough which is generally circular. It has a bearing relief 4211 at its midsection to reduce frictional drag in the passage. A wrench 43 passes I through the socket drive shaft, and the socket drive shaft tool from damage which might occur as the result of excessive torque loads on some of the tool elements.

This invention is carried out by providing a coaxial wrench and socket adapted for rotation relative to each other. By this means, the wrench can engage the pin of the fastener, and the socket can engage the collar so as to tighten the collar onto the pin. In the preferred embodiment of the invention, the socket rotates, and the wrench does not.

According to a preferred but optional feature of the invention, the wrench is held by frictional clutching means so that it will be turned by excessive torques which otherwise might damage it.

According to still another preferred but optional form of the invention, either the wrench or the socket is adapted to retract so as to permit the tool toadvance onto the fastener as the fastener is tightened.

The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings, of which:

Fig. l is a side view, partly in cross-section, of the presently preferred embodiment of this invention, showing a fastener being tightened thereby;

Fig. 2 is a cross-section taken at line 2- 2-of Fig.- 1;

Fig. 3 is an end view taken at line 33 of Fig. 1;

Fig; 4 is a side view, partly in cross-section, of still another embodiment of the invention;

Fig. 5 is-a fragmentary cross-section, taken at line 55 of Fig. 4;

Fig. 6 is a side view, partly in cross-section, of still another embodiment of the invention;

Fig. 7 is a partial cross-section taken of Fig. 6; e

- Fig. 8 is a fragmentary side view, partly in cross-section, showing another means for providing relative axial movement between the wrench and the socket;

Fig. 9 is a fragmentary side View, partly in cross-section, showing the use of a modified wrench for tightening a fastener of a, somewhat different configuration from that shown in Fig. -1; and

Fig. 10 is a cross-section taken at line 10-10 of Fig. 9.

The preferred embodiment of this invention is shown at line 7-7 in Fig. 1 wherein a tool 20 has a frame which may conveniently be made from two parts 21 and 22, the parts being joined together when the tool is assembled. A tool drive shaft 23, which may be driven by a drill motor 24 that is connected thereto by chuck 25, enters the frame through a passage 26. This passage has a pair of needle rotates free of the wrench. A socket 44 has splines 45 which engage splines 46 on the end of the socket drive shaft, which hold the socket with the socket drive shaft for rotation therewith. The socket is provided with a groove 47, and the socket drive shaft is provided with a groove 48. These grooves accommodate a retainer spring 49 between them which holds the socket axially on to the socket drive shaft.

The socket has internal collar engaging surfaces 50 which have the general configuration of a collar to he turned on to a pin. These surfaces form a hexagon as shown in Fig. 3.

The socket has a central port 51 which passes the wrench 43 therethrough. The socket and the wrench have central axes which coincide with axis 29.

The protruding end of the wrench has pin-engaging surfaces 53 which may conveniently be of the Allen-head type, that is, hexagonal, although any other configuration might also be used which will engage the surfaces of a recess in the pin of a fastener to be tightened. The central portion of the wrench is round. As best shown in Fig. 2, the wrench is provided with splines or some other type of interrupted surface such as the hexagonal surfaces 54. These surfaces 54 fit in a clutch socket 55 whichclu-tch socket has a hexagonal opening 56 for receiving the hexagonal end of the wrench. The outer surface 57 of the clutch socket may also conveniently be hexagonal for engaging a clutch band 58. This clutch band is provided with a circular peripheral surface 60 which may preferably have an outwardly convex V shape in cross-section (see Fig. 1). This peripheral surface is gripped by a brake 61 of the Prony type, which can be tightened on to the clutch band by a brakeeadjustment screw 62 (see Fig. 2). The brake restrains the wrenchand, of course, the degree of restraint, from restraint which for all practical pur-' poses is total, to relatively easily yielding restraint, is adjustable by the clutch band. The terms frestraint and restrained as used in this specification and in the claims. cover all such degrees of restraint of rotation against the wrench relative to the frame.

The right hand end of the clutch socket 55 has a {hardened insert 63 against which a thrust bearing 64 bears. This bearing, which may be a ball as shown, is carried in a recess 65 in the drive shaft 23. It will be seen that the action of the coil spring 32 in moving the drive shaft to the left in Fig. 1 tends to keep the thrust bearing ball firmly between and against the drive shaft and the insert 63 of the clutch assembly. This biases the wrench tothe left in Fig. 1.

The clutch socket 57 is axially movable in opposition to the coil spring 32 so that he wrench can be moved axially. The clutch assembly and the frame hold the socket drive shaft 39 against making any appreciable axial movement.

In Fig. 1 there is also shown a fastener for which tool 20 is particularly suited. A fastener of thisnature is generally used for joining a pair of bodies 66 and 67 t0- gether. These bodies have registering holes 68, 69 respectively, through which an externally threaded shank of a pin 70 is passed. The pin has a head 71 which bears against .one of the bodies while the threaded end of the pm projects throughand beyond the bodies. A collar 72 having 'a shear section 73 and a hexagonal socket engaging section 74 is threaded onto the pin.

This fastener may be provided with a washerSS having an annular flange 86, and two flat sides. One flat side bears against body 67, and the other against the collar'72. The Washer has a layer 87, 88 of substantially dry lubricant on both of said flat sides, although the layer 87 adjacent body 67 is optional. A suitable lubricant for this purpose is sold by S. C. Johnson & Son, Inc., located in Racine, Wisconsin, under the name #153 Wax Lubricant Tube Draw. This lubricant is provided in an evaporable liquid base. The base evaporates before the lubricantis used as described below, leaving the dry wax.

This is a polar wax which dries to a thin him. The purpose of this film is to reduce or eliminate the variability of the reaction forces between the collar and the work. When this reaction is constant, then the pre-load on the pin can be accurately controlled by adjusting the torque applied to the collar.

In setting this fastener, the wrench 43 is inserted into a recess 75 in the end of the pin, and the socket 44 engages the hexagonal socket engaging section 74. As can .be seen from the drawings, holding the wrench 43 stationary and turning the socket will cause the collar to tighten on to the bolt until sufficient torque is exerted on the hexagonal socket engaging section 74 that the shearsection 73 fails and the hexagonal section comes free. A more complete description of a fastener of this type and its operation is given in my co-pending patent applicant Serial No. 643,183, filed February 28, 1957, entitled Fastener.

In order to expel the sheared-off hexagonal section from its socket, an ejector means 76 is provided which comprises a retainer ring 77, within the socket, a flanged tubular member 78 surrounding the wrench 43 and a coil spring 79 opposed between the socket and the flange 80 of the member 78. The hexagonal section will force the tubular member 78 back into the socket while the fastener is being tightened. After the shear section has failed and the tool withdrawn, the spring 79 will force the tubular member 78 to the left in Fig. 1 so as to eject the hexagonal section from the socket.

Another embodiment of the invention, utilizing a different type of clutch means, is shown in Fig. 4. A tool 110 has a frame 111 having a clutch cavity 112 and a shaft passage 113 therein. A socket drive shaft 114 is journaled in the shaft passage 113 and has a ring gear between the spur gear 141 and the clutch disc 156.

in-line tool. This tool has a frame 131 which frame is provided with shaft passages '132 and 133. A gear cavity 134 is provided between the shaft passages to accommodate a pair of spur gear pinion shafts 135, 136 which are journaled at their two ends in passages 132 and 133 respectively. These spur gear pinion shafts each have a pair of spur gears incorporated in their length, spur gears 137, 138 being included on pinion shaft 135 and spur gears 139 and 140 being incorporated on pinion shaft 136.

A spur gear 141 is journaled in a bearing 142 in the frame and has a lug 143 for engagement with a shaft of a drill motor (power drive means 145a). A screw 144 provides for retention of the drill motor in the proper location in the neck 145 of the frame. Spur gear 141 makes meshing and driving contact with spur gears 137 and 139.

Another spur gear 146 is mounted coaxially with spur gear 141 and meshes with spur gears 138 and 140. Spur gear 146 is integral with a socket drive shaft 147 which drive shaft extends through a bearing 148 in the frame and receives a socket 149 on its projecting end. The socket drive shaft 147 has a wrench passage 150 extending axially therethrough so as to receive a wrench 151. The wrench and the socket have a common central axis 152.

The wrench is provided with pin engaging surfaces 153 on its end which may form a hexagonal prism so as to form an Allen-head wrench if desired. At its other end the wrench is provided with a tapered head 154 which is tapered so as to fit into a circular tapered recess 155 in a clutch disc 156. The thickness of the head is less than the depth of the recess 155. A coil spring 157 is opposed The coil spring is seated in a recess 158 in spur gear 141, and bears against that gear and against the clutch disc so as to force the clutch disc toward the socket.

As can best be seen from Fig. 7, the clutch disc is generally rectangular and has two arcuate (preferably cir- (see Fig. 5) keyed thereto so that rotation of the ring 'gear as caused by a drive gear 116 will turn the socket drive shaft.

The socket drive shaft 114 has a wrench passage 117 therethrough which accommodates a wrench 118 having a central circular cylindrical portion terminating at the lower end with pin engaging surfaces 119 whichare preferably hexagonal in the shape of the well known Allenhead wrench. The wrench has a shoulder which rests upon the socket drive shaft to limit the downward movement of the wrench. At the upper end of the Wrench there is integrally attached the lower contact plate 121 of an over-riding clutch 122. A matching upper contact plate 123 is held against the contact plate 121'by pressure exerted from a leaf spring 124 against a shaft to which the upper plate is attached. Shaft 125 is hexagonal, and thereby keyed into a hexagonal passage 126 so that it isheld against rotation but is axially movable against the force of the spring 124. An ejector means 76 is provided in the socket in the same manner as in the tool of Fig. 1, and'like reference numerals are used.

Fig. 6 shows a tool which is particularly suitable foruse with a drill motor, inasmuch as it is an entirely cular) cut- outs 159, 160 which bear against the spur gear pinion shafts 135 and 136, respectively. These cut-outs prevent the clutch disc from rotating in the frame.

An ejector means 76 (not shown) can be provided in the socket in the same manner as in the device of Fig. 1.

In all of the aforesaid embodiments, provisions have been made for the wrenches to be axially movable while the socket is held substantially axially immovable. In general when installing the fastener of the type shown in Fig. 1, such an arrangement is .to be preferred both for the most eifective tightening of the fastener and for simplicity of tool construction. However, sometimes it may occur that a retractable socket and a non-retractable wrench is to be preferred. In Fig. 8, such a device is shown. A wrench may be substituted for the wrench in any of the above tools, and be keyed so that it cannot move axially, although it can be turned. A socket drive shaft 166 may also be substituted for the corresponding part in the above tools. The socket drive shaft is provided with a tubular portion 167 within which a socket 168 is slidably disposed. A coil spring 169 is opposed between the tubular portion 167' and the socket 168 so as to force the socket away from the frame. A pair of pins 170, 171 projects into the tubular portion and also into axial slots 172, 173 respectively in the socket. The-socket will thereby turn with its drive shaft, and can slide axially therein.

Collar engaging surfaces 174 are provided inside the socket, and these surfaces may be provided in an hexagonal pattern if desired. The socket and the wrench have a common central axis 175.

A spur gear 176 is made integral with the socket drive shaft 166 so that when this gear is driven by any desired means, the socket will rotate relative to the wrench. The wrench may include any of the clutch devices shown in the above described embodiment.

if desired, an ejector means such as means 76 maybe provided in this socket as shown. These are identical with the means shown with Fig. 1, like parts bearing identical numerals.

Occasionally, it may be desired to form the fastener with a protrusion on the pin for being gripped instead of a recess. Such a modification of the pin is shown in Figs. 9 and 10, wherein the protrusion comprises a tongue 180 having a rectangular cross section protruding from the end of a pin 181. In all other respects the pin can be the same as the pin 70 shown in Fig. 1, of course omitting the recess at the end thereof. A collar 72 identical with that shown in Fig. 1 is to be threaded on to the pin by a socket 182. A wrench 183 has its end modified with a straight slot 184 for receiving the tongue 180. The socket and the rest of the wrench may be made according to any of the above described embodiments. This device illustrates the fact that the hexagonal shapes provided on the nut and in the socket and also the Allen-head type end on the wrench are not limitations on this invention. Rather, any desired pin and collar engaging surfaces may be provided as appropriate to the fastener being tightened.

The operation of these devices will now be described. With respect of the device of Fig. 1, the pin will first be inserted in the registering holes 68 and 69 in the plates 66 and 67. The collar will then be started upon the pin. The wrench 43 is inserted into the recess in the end of the pin and the socket 44 is pushed over the hexagonal portion of the collar. This action retracts ejector means 76.

Thereafter, the drill motor 24 or other means for tuming the drive shaft 23, is powered so as to rotate the same. .This rotation is transmitted by the gear frame from the drive shaft through the pinion 33 to the socket drive shaft 39. The wrench 43 does not initially rotate because it is held by the clutch, and the collar will therefore be turned onto the pin by the socket, because the wrench holds the pin against rotation. After the collar has been seated against the body 67, the motor will exert a torque on the hexagonal section until a sufiicient torque is exerted that the fastener fails at the shear section 73 at which time the load is relieved from the socket 44. The tool can then be pulled off of the fastener leaving the remainder of the collar (to the left of the shear section in Fig. 1) torqued to a value determined by the yield strength of the shear section. In normal cases this is all that occurs. However, it sometimes may occur that the shear section might no fail at a torque limit below that which would damage the wrench 43. In fact, wrenches have been destroyed by this means in wrenches not involving yieldable means for protecting the same. As the tool advances toward the body 69 when the collar advances on the pin, the wrench will be forced inwardly against spring 32.

In the tools shown, the clutch is adjusted so as not to yield, but instead, to restrain the wrench up to torque values needed to set the fastener, and below values which would harm the tool. In the tool of Fig. l, the clutch band begins to shift in the brake 61 at a torque value which is determined by the setting of the brake adjustment screw 62. The torque exerted on the wrench can therefore never exceed a safe value, and the wrench is protected against distortion.

The operation of tool 110 shown in Fig. 4 is as follows. The socket 127 is placed over the collar, and the wrench 118 is inserted into the recess in the pin. Thereafter the drive gear 116 is turned by power applied in any desired manner so as to rotate the socket drive shaft 114 and thereby the socket 127, tightened the collar on the pin.

As the socket advances onto the pin the wrench 118 will be forced in an axial direction upward as shown in Fig. 4. This force is exerted against the force of spring 124. This tends both to retract the wrench 118 and keep the over-riding clutch 122 engaged by forcing the contact plates 121 and 123 together. If an overload on the wrench occurs, then the over-riding clutch will slip by virtue of the lands on the contact plate 121 and 123 climbing each other in a well understood manner. It will be recognized that contact plate 123 is held against rotation because of the hexagonal shape of its shaft 125.

The operation of tool (Figure 6) will now be described. A drill motor (not shown) can be fitted on to the lug 143 and held in place by screw 144, whereupon turning the gear train starting with spur gear 141, and ending with the spur gear 146 on the socket drive shaft 147 drives the socket 149 to turn a collar on to a pin in the manner as heretofore described. q

The coil spring 157 presses the clutch disc 156 toward the socket drive shaft. As can best be seen from Fig. 7, the cut- outs 159 and 160 fit around the shafts of the spur gear pinions so that the clutch disc is not rotatable. It will also be appreciated that the thickness of the head 154 of the wrench is less than the gap of the circular tapered recess 155. Therefore when the spring moves the clutch disc to the right as shown in Fig. 6 and pressure of the tool against the pin moves the wrench 151 to the left a contact is made between the wrench and the clutch disc which prevents the wrench from rotating at torques less than some predetermined value.

As' the socket moves along the pin while threading-on the collar, the wrench 151 retracts into the tool, pushing te clutch disc along with it. If a torque overload is exerted on the tool in excess of the torque which can be held by the disc, then the wrench simply slips in the clutch and thereby is protected against the damage due to overloads on the tool.

Occasionally it may be desired to have the socket retract, instead of the wrench. This is not ordinarily the situation, but in the event that it is, any of the above described wrenches may be given a collar or some other type of key to hold it against axial movement while still permitting the same slipping rotational movement in the clutch. Then the socket drive shaft 166 of Fig.- 8 may be substituted for the other socket drive shaft, and be driven by the spur gear 176 attached thereto, from means such as spur gear 116 in Fig. 4. The socket 168 will engage the collar in the usual manner, while the wrench is inserted into the recess in the pin.

The socket drive shaft does not appreciably move axially, and neither does the wrench in this device, and they do not move appreciably axially relative to each other. However, the socket 168 does move axially within the socket drive shaft in opposition to the coil spring 169. The pins 170 and 171 in slots 172 and 173 respectively keep the socket from turning relative to the drive shaft and cause the socket to be restrained to only axial movement relative to the said drive shaft.

It also may occur that instead of having a projecting end on the wrench such as the aforesaid Allen-head ends for the purpose of extending into a recess in the fastener, the fastener may instead be provided with means such as the tongue shown in Fig. 9, and the wrench will therefore be given a matching slot 184 for receiving the same. This simply comprises a modification of the pin engaging surfaces on the end of the wrench and no other alterations need be made in the aforesaid tool for this purpose.

All of the above tools provide a means for tightening down a threaded fastener particularly a fastener of which a portion is to be torqued off so as to limit the torque applied thereto. In addition these tools are protected against damage due to torque overloads which otherwise might twist the wrench, thereby rendering the wrench useless and perhaps also damaging other parts of the tool structure.

This invention is not to be limited by the embodiments shown in the drawings and described in the description, but only in accordance with the scope of the appended claims.

I claim:

1. A tool for tightening a threaded fastener in which a collar is threaded onto a threaded pin comprising: a

frame; a socket drive shaft jonrnaled in the frame and supported :by the frame .for rotation relative thereto; a gear onssaidsocket-drive:shaft;,.a socket member on said socket driveshaft, :saidpsocket member being adapted to -.engage the collar to turn the same .onto the vpin; a wrench Imember adapted to engage the ,pin .to restrain it from rotation, said wrench :memberpassing through the socket member, the wrench member being axially movable-irelative-rto the frame and restrained against rotation relative thereto; a tool tdriveshaftjonrnaled to the frame and {axially shiftable relative thereto; bias :means .pressing said L-tool driveshaft toward the wrench member; a ,gear on said tool drive shaft, said tool drive shaft, socket member and wrench member having coincident central axes; a pinion gear laterally spaced from the aforesaid axes and interconnecting the gear on the tool drive shaft withthe gear on the socket drive shaft, the gears on the tool drive shaft and the pinion gear being of sufficient axial length 'to permit relative sliding between them while the said gears remain enmeshed; and bearing means dis- ;posed between the tool drive shaft and the wrench member enabling the tool drive shaft to rotate. independently'of the wrench member, the bearing means being operative to transmit bias force from the tool drive shaft to the wrench member to axially shift the wrench member toward a fastener to be engaged by the tool.

2. A-tool for tightening a threaded fastener in which a collar is threaded onto a threaded pin comprising: a frame; a socket drive shaft journaled in the frame and suppnrted by the frame for rotation relative thereto; a "gear on said socket shaft; a socket member on said socket drive shaft, said socket member being adapted to engage the collar and turn the same onto the pin; a

wrench member adapted to engage the pin to restrain it :from rotation, said wrench member passing through the socket member, the wrench member being axially movable relative to the frame and restrained against rotation relative thereto; a tool drive shaft journaled to the frame and axially shiftable relative thereto; a gear on said tool drive shaft, said tool drive shaft, socket member, and wrench member having coincident central axes; a pinion gear having an axis of rotation laterally spaced from the said axes and interconnecting the gear on the tool drive shaft with the gear on the socket drive shaft, thegear on the tool-drive shaft and the pinion gear being of ,suificient axial length to permit relative sliding between them while they remain enmeshed; bias means operable on the tool drive shaft and effective to press said wrench member toward a fastener engaged by the tool; whereby the tool drive shaft is adapted to rotate independently of the wrench member but is operative with the bias means to axially shift the wrench member toward the fastener to be engaged.

3. A tool according to claim 2 in which the bias means comprise compressible springing means disposed between and hearing against the tool drive shaft and the wrench member which press said wrench member axially toward a fastener engaged by the tool, and react between the tool .drive shaft and the wrench member as a bearing enabling the tool drive shaft to rotate independently of the wrench member while exerting an axial "force thereon.

References Cited in the file of this patent UNITED STATES PATENTS

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