US3196544A

US3196544A - Drafting machine

Info

Publication number: US3196544A
Application number: US147680A
Authority: US
Inventors: Allister L Baker; William R Krause
Original assignee: Keuffel and Esser Co
Current assignee: Keuffel and Esser Co
Priority date: 1961-10-25
Filing date: 1961-10-25
Publication date: 1965-07-27
Anticipated expiration: 1982-07-27

Description

J ly 19765 A. L. BAKER ETAL DRAFTING MACHINE 5 Sheets-Sheet 1 Filed Oct. 25. 1961 ATTORNEY A. L. BAKER ETAL 3,196,544

Jul 27, 1965 DRAFTING MACHINE Filed 0012-. 25, 1961 3 Sheets-Sheet 2' INVENTORS f4 44 445 48 f. J3 William )Zfiause +1 AZZisterLfia/wr ATTORNEY July 27, 1965 A. L. BAKER ETAL 3,196,544

DRAFTING MACHINE Filed Oct. 25, 1961 3 Sheets-Sheet 3 ATTORNEY 3,196,544 DRAFTING MAtIHHQ-E Aliister L. Baker, Deuville, and William R. Krause, Secaucus, N..l., assignors. to Kcuflel & Esser Company, Hobohen, N..l'., a corporation of New .iersey Filed Get. 25, 1961, Ser. No. 147,686 4 Qlaims. (tDl. 33- 19) The present invention relates to a drafting machine and more particularly to a drafting machine having anchor and drafting head arms pivotally connectedtogethor at one "endwith the other end of the anchor arm pivotally mounted on an anchor support on the edge of a drafting board and a drafting head on the other end of the drafting head arm, carrying a protractor and line guides which are maintained inparallel relation by a pulley and belt system.

Heretofore draftingmachines of this type have been provided but they have been expensive to manufacture making them unavailable to schools and to students and therefore the students have not been able to take advantage of the increased efl-"rciency in learning and working resulting from the use of such drafting machines. One reason for the expense of manufacture was the skilled labor to obtain the accuracy required in the parts.

An object of the present invention is to provide a drafting machine of the pivoted, arm type which is accurate in use and can be made at a cost to be available to students and to other draftsmen with limited resources.

Another object is to provide a means to maintain the pawl for the drafting head in an operative or inoperative position and to provide easily operable means to restore; the operation of the pawl. A further object is to provide means to change the drafting head in infinite angular positions.

Another object is to provide means to connect a drafting machine to a drafting table to prevent theft thereof.

Other and further objects will be apparent as the description proceeds and upon reference to the accompanyline and showing in phantom outline the position retain:-

ing pawl in its. inoperative position out of engagement with the notched disc and showing the clamp for set ting intermediate angular adjustments and also showing the leaf spring detent operative on the control lever for the pawl operated slide. for retaining the pawl in operative or inoperative positions.

FIG. 3 isa vertical section taken substantially on line 33 of FIG. 1 showing the drafting head plate adjustably mounted in the bore of the control pulley hub and showing the usual pawl releasing arrangement and the novel push button means to restore the pawl to operative position.

FIG. 3A is a fragmentary section on line 3a-3a of FIG.v 3 showing the pawl control. bar in the cup and the pawl operating wheel.

FIG. 4 is a section taken substantially on line 4-4 of FIG. 2 through the infinite position clamping control toretain the drafting head in adjusted position-s.

FIG. 5 is a planview of the pivotal connection joint between the arms which are assumed to be in superimposed position and showing the adjustment for tension- .ing the straps.

United States Patent FIG. 6 is a vertical axial section of the two arms of the drafting machine taken substantially on line 66 of FIG. showing the means for obtaining the frictional adjustment between the arms and illustrating the bearing structure.

FIG. 7 is a plan view of the anchor end of the anchor arm showing a portion of the anchor bracket mounted on a drawing board.

FIG. 8 is an axial section taken substantially on line 88 of FIG. 7 through the pivot connecting the anchor arm and the anchor bracket.

FIG. 9 is a horizontal section just above the anchor pulley taken on line 99 of FIG. 8 with the arm mounting fitting removed therefrom.

FIG. 10 is a horizontal section taken substantially on line t3-ll of FIG. 8 showing the shape of the T-groove which serves to retain the anchor pulley in fixed adjusted position.

FIG. 11 is an enlarged fragmentary circumferential section looking toward the axis taken along the pulley grooves of FIGS. 10 and 12 through the locking screw and nut of the anchor pulley retaining structure.

FIG. 12 is a fragmentary enlarged section taken sub stantially on line 1212 of FIG. 11 showing the bolt head of the locking bolt in the T-groove.

Referring more particularly to the drawings, a drafting board 15 has mounted thereon an anchor clamping bracket 16 which is held in position by a clamping screw 17 and by one or more screws passing through countersunk screw receiving apertures in a flange 18 which anchor bracket flange is covered by a resilient rubberlike cover w secured thereto by adhesive or other means to prevent damage to line guides. The anchor bracket includes an upstanding bearing boss 20 which is perpendicular to the clamping surface of the flange 18 and an angularly adjustable anchor pulley 21 having an integral tubular shaft 22 which rotatably adjustable in the anchor bearing boss 20. The anchor pulley 21 is provided with a circumferential groove 23 of T-shape in radial cross-section with such groove having the flange portions removed at 24 to provide for the reception of a square head 25 of an angular position locking bolt 26, the shank of which bolt passes through an apereutre in a lug 27 extending radially from the upper end of the anchor bearing boss 2d as clearly shown in FIGS. 10, 11 and 12. The anchor pulley 21 is provided with a circumferential V-groove 28 on its upper surface while an Allen head stop screw 29 is threadedly received in a threaded aperture extending between

grooves

23 and 28 and such stop screw 29 projects into the path of a stop lug 30 extending into a circular recess of a first fitting 31 which recess 32 receives the anchor pulley 21', said fitting having a pair of parallel tube receiving sockets 33 extending tangentially in one direction. A pivot shaft 34 is fixed to said first fitting 31 by means of one end of such pivot shaft 34 extending into a counter bore in the recess of fitting 31 and being held in position by a screw 35 passing through the fitting wall and into a threaded bore in said pivot shaft 34. The pivot shaft 34' is retained in the tubular shaft 22 of the anchor pulley 21 by a split ring 36 which also serves to retain needle bearings 37 and any suitable spacing elements in the circumferential space between the pivot shaft 34' and the anchor pulley tubular shaft 22 to assure ease of movement of the fitting 31 and of the anchor and drafting head arms of the draft ing machine. The pulley 21 is retained in position by the locking bolt 26 and a peripherally grooved hexagonal nut 38 held in operative. position in a broached: hexagonal opening in wrench handle 33'' having an Allen-head screw 39 threaded through the periphery of the wrench 38 and into the groove. of the hexagonal nut- 38 so that contacting the lug 27, thereby positively retaining the.

drafting machine on the anchor clamprand also maintaining the desired angular adjustment of the anchor pulley21.'..f a V A'second fitting 40.provided.with a circular recess and a pair of sockets in'alignment with the sockets of by a plurality of screws, 65. Theweb of the pulley 60 is spaced above the lower side of the pulley providing a recess for flange 66A of tubular flanged shaft 66, the

the first fitting is connetced by tubes 41 to the first-fitting 31, said tubes being freely rotatable in their sockets and the structure being maintained in'connected. condition by the tension of the control strap 42 which engages the periphery of the anchor pulley 21 and the periphery. of'

the upper portion. of a double pulley 43. The t'ension of the control strap is adjusted by turnbuckle type device.

A third fitting 44 similar to the second fitting 40 and bores 40B and 44B respectively. Said second and third fittings are pivotally mounted on a tubular shaft 45 extending through the bosses and through a bore in the web offthe double pulley 43 which provides for rotation of such double pulley"'43, the

fittings

40 and 44 being rotatable on the .tubular shaft 45 by means of needle bearings 46 which ar e maintained in spaced relation and in operative position by washers 47 abutting the boss of double pulley'43 and by split rings 48 in grooves of shaft 45 which maintain the parts in assembled condition.

Friction washers 49 of cork are positioned against wear A headed friction-producing bolt 52 passes through washer 51 and into the tubular shaft :45 and extending to adjacent the other end of such tubular shaft.' A flanged tubular nut 53 having a circumferential groove receiving split ring 48 has internally threaded tubular portion thereof extending into a counterbore in the other end of tubular shaft 45 'and is threaded onto the end threads of friction-producing bolt 52. To retain, the nut 53 against rotation'in the tubular shaft the tubular shaft a is provided with diametrically opposite pin receiving slots 54 and the nut is provided with a transverse bore which receives a pin 55 for preventing relative rotation of said nut with respect to said tubular shaft 45.whereby able slot or'spaced wrench-receiving apertures may be provided in nut 53 to prevent rotation of the nut. assembly during adjustment. The bolt 52 is provided with a nylon insert 52A in a transverse bore-and such nylon insert is sufficiently long to engage the threads of the nut 53 to retain the nut and bolt in adjusted condition.

flanged shaft being rotatable in the bore of the third pulley shaft 59.- The flanged tubular shaft is provided with a shoulder providing clearance above the tubular pulley shaftby reducing the diameter of the. shaft 66 and such'reduced portion is received in a bore, in the bottom of cup 67 which cupis. secured to the shaft by a nut 68. The cup 67 has a radial flange 69' on the outer circumference of: the cup 67 and rotatably supported on the .cup 67 and engaging the flange 69 is a pawl-operating wheel 70 having a boss 71 extending along the periphery of the cup. The cup. 67 of the pawl-operating wheel is provided with circumferentialslots bounded by

edges

72, 72.. The boss 71 has circumferential slots defined by edges 72A and 72B spaced apart somewhat greater than edges 72. A drafting head rotating knob handle 73 is fixed to the cup 67 by a screw 74 and such knob is provided with a central bore and a count'erbore whichreceives a flanged push button 75 having a boss 76 slidably mounted in the bore of the knob 73 and normally urged to the inoperative position shown in FIG. 3 by a coiled compression spring 77, the knob being held in assembled relation by a split I ring 78. A double tapered lever 79 having a fulcrum flange intermediate its ends is positioned in the passage of the flanged hollow shaft 66, one end of said double tapered lever having a bore therein and the other'end having an enlargement. A pin 80 having a head at one end and anintermediate enlargement is mounted in the'bore of said one end of said double tapered lever 79. V A control bar 81 having a central aperture is positioned in the cup. 67 and extends into the slots in boss 71 and cup 67 with the ends of such control bar in the path of the abutment surfaces 72 of moving the aperture in control bar 81 from the position shown .in FIG. 3 to a displaced position as shown in phantom by dash-dot line in. FIG. 3A and moving double tapered lever 79from the position shown to a position in which the angle extends from the upper left to the lowerright as viewed in FIG. 3. This dotted line poi sition of FIG. 3A corresponds to. the phantom dashdot line of the pawl in FIG. 2. The boss 76 of the In normal use the pulley 43 is fitted with sufficient tightnesson tubular shaft 45 to prevent relative rotation therebetween and merelyiby holding the'parts of the drafting machine in fixedrelation the tubular shaft and the nut 53 willbe prevented from'rotation and frictional push button 75 is provided with, a conical downwardly flaring bore 76A which in the inoperative position shown permits the double tapered lever 79 to oscillate from the full linepawl engaging position shown to a pawl releasing position. p

Mounted on the flange 676A7of the flanged hollow shaft 66 isthe drafting head plate 83 which is'fixed to such flange 66A by suitable screws and such plate 83'is provided with a slot 84 in which a slide 85 is mounted, such 'slide' being urged to a retracted position by a tension ing 58 therein which receives a hollow shaft 59 of a .third pulley 60providing a drafting head support, which pulley is retained in position by a split ring 61 abutting the upper surface of bushing 58 with the web of pulley 60 lying beneaththe bushing, sa id pulley being provided with a circumferential rabbet which receives an annular protractor '62,'a spacing ring 63 and a notched disc 64 which-are held in fixedpositionto the third pulley 60 spring 85A and being under the control of double tapered lever 79 'ofwhich the enlarged lower end is received in an aperture 85B in the slide.

The aperture 85B is provided with an inwardly extending flange at its lower end thereby retaining double tapered lever 79 in operative position between control bar 81- and slide 85. The slide 85 is retainedfin the .slot 84 by a control lever. 86 pivotally'mounted on one side of the slot'84 on the drafting head plate 83 and extending underneath the drafting head plate and under'slide 85 and operatively connected to the slide 85 by-a rivet 85C fixed to the slide and extending downwardly into a radial slot in the control lever 86. .Additional meanssuch as a strut between the walls of theslot 84 may assist in retaining the slide. The

other end of the slide 85 is. operatively connected by a rivet 85D fixed to and extending upwardly from the slide and received in a slot of a pawl 87 which pawl is pivotally mounted on the upper surface of drafting head plate 83. The projection tip of such pawl 87 is receivable in any one of the notches of the notched disk 64 thereby retaining the drafting head plate in fixed position with relation to the notched disk 64 and the protr-actor. The control lever 86 projects beyond the other side of slot 84 and has a tooth 86A which engages a wedge-shaped cam portion of a leaf spring 86B, which leaf spring is adjustably secured to the under surface of the plate 83 by suitable screws 86C passing through slots in a flange fixed to the leaf spring 8613 whereby the control lever 86 will be retained in either of the positions shown in FIG. 2 in which the projection of the pawl 87 is in engagement with a notch in the notched disk 64 as shown in full lines holding the drafting head in one of the 15 adjusted positions or the pawl is in the other position as shown in dash-dot lines in which the pawl is released. In the released position the left edge of the tooth 86A of control lever engages the right edge 86D of the wedge-shaped cam portion of the leaf spring 86B thereby retaining the slide 85 against the tension of the spring 85A corresponding to the dash-dot line position of the parts in FIG. 3A whereby the drafting head plate 83 is free to move to any azimuth position relative to the protractor 62.

To retain the drafting head plate in fixed position relative to the protractor when the pawl is out of engagement with the notched disk, a flanged Z-shaped clamp element 88 (FIG, 2 .and 4) is positioned on the drafting head plate 83 with one end of the base of the Z-shaped clamp element against the palte 83 and a flanged screw '89 passes through an aperture in the drawing head plate 88 and projects thereabove, passing through an enlarged aperture in the stem of the Z-shaped clamp element 88 and threaded into the threaded bore of a lever 89A whereby motion of the lever will cause movement of the Z- shaped clamp 88. Precise adjustment is obtained by a locking screw 89B threaded into the drafting head plate with its head engaging the flange of flanged screw 89 to hold the flanged screw 89 in a position so that limited movement of lever 89A will produce the desired clampring action. Mounted on the drafting head plate 83 is an abutment 88A underlying the pr-otr-actor 62 beneath the (flange 88B of the flange-d Z-shaped clamp 88 whereby the clamping action produced will react on the abutment 183A and avoid objectionable distortion.

When it is desired to restore pawl 87 to operative position depression of bottom 76 causes double tapered lever 79 to be restored to the full line position so pawl 87 engages one of the notches in notched disk 64. It will be apparent that the movement of the push-button 75 downwardly when the pawl is in the full line position of FIGURE 2 causes the lever 79 to move to a central position thereby moving the pawl 87 to an intermediate position in which the pawl is disengaged from the notches of the notched disc 64 and the drafting head plate 83 can then be turned to any desired angle to position the scale carrying lugs 90 and 91 in the desired position, and upon release of the push-button 75 the pawl will engage the adjacent notch of the notched disc 64.

It will be apparent that the various pulleys are connected by straps 42 tensioned sufliciently by turnbuckle type tension element-s 42A to maintain the fittings in secure assembled relation and also to assure that there a is no slipping between the straps 42 and the pulleys cooperating therewith.

:From the above description it will be apparent that the present invention prOVides means to maintain the line guide scale carrying lugs 90 and 91 of drafting head plate '83 in proper relation so that line guide scales 90A and 91A carried thereby will be maintained in their parallel relation or in a definite angular relation in accordance with the adjustment obtained between the protractor 62 and an index 93 fixed to the drafting head plate 83 which index also serves as a housing for the pawl 87.

It will be apparent that various changes may be made within the spirit and scope of the invention as defined in the valid scope of the appended claims.

What is claimed is:

l1. A drafting head structure comprising a drafting head support movable in all directions on the surface of a drawing board while maintaining a line of said support in parallel relation at all times, a shaft having a bore rotatably mounted on said support, a drafting head plate rfixed to said shaft, a cup having a bore in the bottom thereof mounted on said shaft in fixed relation, a pawloperating wheel having a boss projecting therefrom rotatab-ly mounted on said cup, said cup and said boss of said pawl-operating wheel being provided with slots therein, a drafting head rotating knob mounted on said cup, a control bar positioned in said cup and extending diametrically into the slots of said cup and boss of said pawloperating wheel, a lever pivotally mounted in said bore of said shaft and being connected to said control bar, a link mounted in said drafting head plate and connected to said lever, and a pawl operatively connected to said link whereby said pawl can be operated by rotation of said pawl-operating wheel, a disc mounted on said drafting head support for cooperation with said pawl to retain said drafting head in fixed relation to said dnafting head support, a cam push-button mounted on said drafting head operating knob and having its cam surface cooperable with said lever in one direction, and a spring operable to move said pawl into operative position with respect to said disc.

2. The invention according to claim 1 in which the cam push button is mounted for axial movement in a central bore of said drafting head rotating knob and the cam surface is concave conical embracing the said lever pivotally mounted in said flanged shaft.

3. The invention according to claim 2 in which a yieldable detent cooperates with said pawl to retain said pawl out of engagement with said notched disk to permit infinite :ang-ular adjustment of said head and said cam push button will release said yieldable detent so that said pawl can enter a notch of said notched disk.

*4. A drafting head structure comprising a drafting head support movable in all directions on the surface of a drawing boa-rd while maintaining a line of said support in parallel relation to all times, a shaft having a bore rotatably mounted on said support, a drafting head plate fixed to said shaft, a lever pivotally mounted in the bore of said shaft, a link mounted on said drafting head plate and connected to said lever, a pawl mounted on said drafting head plate and connected to said link, a disc fixed to said drafting head support and cooperable with said pawl to retain said drafting head in fixed relation to said support, a cam push-button mounted for axial movement relative to said shaft and having a cam surface cooperable with said lever to move said lever in one direction, and yieldable means operable to move said pawl into operative position with respect to said disc.

References (Zited by the Examiner UNITED STATES PATENTS 2,243,734 5/41 Euban-ks 33-793 2,25 6,445 9/ 41 Wiederm'ann 3379. 3 2,266,862 12/ 41 Cunningham 248- 3 61 2,289,126 7/42 Keufiel 3379 2,381,382 1 0/ 43 Euban'ks 33-793 2,347,625 4/44 Wiederm ann 3'3-79.3 2,377,429 6/45 Ketting 33--79.3 2,43 8,220 3 /48 Kettin g 3 3--79.3 2,4645 3/49 Ketting 3379.'3 2,612,694 10/ 5 2 Vaughan 33--79.3 2,663,344 12/ 5 3 Burdi-ck 15 17 2,917,267 12/59 Riddle 248-361 FOREIGN PATENTS 6,91 7 1/57 Germany.

ISAAC LISAN'N, Primary Examiner.

Claims

1. A DRAFTING HEAD SURFACE COMPRISING A DRAFTING HEAD SUPPORT MOVABLE IN ALL DIRECTIONS ON THE SURFACE OF A DRAWING BOARD WHILE MAINTAINING A LINE OF SAID SUPPORT IN PARELLEL RELATION AT ALL TIMES, A SHAFT HAVING A BORE ROTATABLY MOUNTED ON SAID SUPPORT, A DRAFTING HEAD PLATE FIXED TO SAID SHAFT, A CUP HAVING A BORE IN THE BOTTOM THEREOF MOUNTED ON SAID SHAFT IN FIXED RELATION, A PAWLOPERATING WHEEL HAVING A BOSS PROJECTING THEREFROM ROTATABLY MOUNTED ON SAID CUP, SAID CUP AND SAID BOSS OF SAID PAWL-OPERATING WHEEL BEING PROVIDED WITH SLOTS THEREIN, A DRAFTING HEAD ROTATING KNOB MOUNTED ON SAID CUP, A CONTROL BAR POSITIONED IN SAID CUP AND EXTENDING DIAMETRICALLY INTO THE SLOTS OF SAID CUP AND BOSS OF SAID PAWLOPERATING WHEEL, A LEVER PIVOTALLY MOUNTED IN SAID BORE OF SAID SHAFT AND BEING CONNECTED TO SAID CONTROL BAR, A LINK MOUNTED IN SAID DRAFTING HEAD PLATE AND CONNECTED TO SAID LEVER, AND A PAWL OPERATIVELY CONNECTED TO SAID LINK WHEREBY SAID PAWL CAN BE OPERATED BY ROTATION OF SAID PAWL-OPERATING WHEEL, A DISC MOUNTED ON SAID DRAFTING HEAD SUPPORT FOR COOPERATION WITH SAID PAWL TO RETAIN SAID DRAFTING HEAD IN FIXED RELATION TO SAID DRAFTING HEAD SUPPORT, A CAM PUSH-BUTTON MOUNTED ON SAID DRAFTING HEAD OPERATING KNOB HAVING ITS CAM SURFACE COOPERABLE WITH SAID LEVER IN ONE DIRECTION, AND A SPRING OPERABLE TO MOVE SAID PAWL INTO OPERATIVE POSITION WITH RESPECT TO SAID DISC.