US3040347A

US3040347A - Automatic edge binding machines

Info

Publication number: US3040347A
Application number: US81547A
Authority: US
Inventors: Hans C Paulsen
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1961-01-09
Filing date: 1961-01-09
Publication date: 1962-06-26
Anticipated expiration: 1979-06-26
Also published as: DE1176523B

Description

June 26, 1962 H. c. PAULSEN AUTOMATIC EDGE BINDING MACHINES l2 SheetsSheet 2 Filed Jan. 9, 1961 June 26, 1962 H. c. PAULSEN AUTOMATIC EDGE BINDING MACHINES 12 Sheets-Sheet 3 Filed Jan. 9, 1961 June 26, 1962 H. c. PAULSEN 3,040,347

AUTOMATIC EDGE BINDING MACHINES Filed Jan. 9, 1961 12 SheetS- -Sheet 4 Y "war W 40a 26 j June 26, 1962 H. c. PAULSEN AUTOMATIC EDGE BINDING MACHINES l2 Sheets-Sheet 5 Filed Jan. 9, 1961 June 26, 1962 H. c. PAULSEN AUTOMATIC EDGE BINDING MACHINES 12 Sheets-She et 6 Filed Jan. 9, 1961 0 Z w J 2 wm A d m 0 "w W 3 a W 3 6 W 3 3 June 26, 1962 H. c. PAULSEN AUTOMATIC EDGE BINDING MACHINES 12 Sheets-Sheet 7 Filed Jan. 9, 1961 June 26, 1962 H. c. PAULSEN AUTOMATIC EDGE BINDING MACHINES 12 Sheets-Sheet 8 Filed Jan. 9, 195

June 26, 1962 H. c. PAULSEN 3,

AUTOMATIC EDGE BINDING MACHINES Filed Jan. 9, 1961 12 Sheets-Sheet 9 13 17 as T I 36 a4 1366' rl June 26, 1962 Filed Jan. 9, 1961 H. C. PAULSEN AUTOMATIC EDGE BINDING MACHINES 12 Sheets-Sheet 10 June 26, 1962 H. c. PAULQSEN AUTOMATIC EDGE BINDING MACHINES l2 Sheets-Sheet 11 Filed Jan. 9, 1961 avg mww s N3 L $6 Q ww Maw June 26, 1962 H. c. PAULSEN 3,040,347

AUTOMATIC EDGE BINDING MACHINES Filed Jan. 9, 1961 12 Sheets-Sheet 12 United States Patent 1 3,040,347 AUTOMATIC EDGE BINDING MACHINES Hans C. Paulsen, Lexington, Mass, assignor to United Shoe Machinery Corporation, Boston, Mass, a corporation of New Jersey Filed Jan. 9, 1961, Ser. No. 81,547 16 Claims. (til. 12-245) This invention relates to machines for the adhesive attachment of strips of material to work pieces, and is herein disclosed, by way of example illustrative but not limitative thereof, as embodied in a machine for adhesively attaching a binding tape around the edges of insoles for use in shoes in which substantial portions of the insoles are exposed, as for instance in the toe, shank and heel portions.

Insole edge binding as heretofore practiced has consisted of stitching a binding tape folded over the insole edge. One evident and serious disadvantage of this method is that the binding tape cannot be snugly attached throughout its entire width, and is therefore subject to very considerable wrinkling. Further, as it is not possible to stitch up to the edges of the folded strip, there is left some portion of the strip, beyond the line of stitching, unsecured to the insole, and hence subject to curling away from the insole, with resultant unsightly effects on the appearance of the shoe. To remedy these defects it has been proposed to secure by stitching a binding tape previously coated with pressure responsive adhesive. While this method i superior to stitching alone, it is more costly as well as inconvenient, since the adhesive coating, usually applied to the tape long before the tape is used, must be activated to render it tacky.

It is an object of the present invention to provide a means of attaching a binding tape to a work piece, for example an insole, by use of which means a binding tape may be coated with adhesive and permanently bonded to the insole in a progressive and continuous operation, whereby the disadvantages cited above are obviated, while producing a snug and uniform bond of the tape all around the margin of the insole.

To this end the herein illustrated machine comprises means which draw a dry, uncoated tape from a source of supply past a nozzle which coats the tape progressively with adhesive in advance of the point of convergence between the tape and an insole located on a support, which means also press the successive adhesive coated portions of the tape against the opposite surfaces of the insole margin and feed the insole and the tape; means which progressively feed from a source of supply a dry thermoplastic adhesive to a melting unit in which it is reduced to a fluid state and from which it is supplied to the nozzle for application to the tape; means operated in advance of the tape pressing and feeding means to-wipe the successive adhesive coated portions of the tape over the insole edge and inwardly against the opposite surfaces of the marginal portion ofthe insole; means including a valve which controls the admission of fluid adhesive to the nozzle; power means for operating the tape pressing and feeding means, the adhesive feeding means, and the tape wiping means to attach a binding tape to an insole in a continuous operation; operator-controlled means for alternately rendering the power means operative and inoperative; valve operating means actuated, when the operator-controlled means is operated to render the power means operative, to open the control valve to admit adhesive to the nozzle tape severing means; and means for actuating the tape severing means and for simultaneously casing the valve operating means to close the control valve and terminate the supply of adhesive to the nozzle.

3,64%,347 Patented June 26, 1962 ice The various features and advantages of the invention will now be described in more detail in connection with the accompanying drawings and particularly pointed out in the claims.

In the drawings,

FIG. 1 is a view in front elevation of the head of an edge binding machine in which the invention is illustrated as embodied;

FIG. 2 is a view in front elevation of the lower portion of the machine; 7

FIG. 3 is a perspective view of the machine illustrated in FIG. 1;

FIG. 4- is a perspective view substantially similar to FIG. 3, with certain parts omitted;

FIG. 5 is a detail view in front elevation of work feeding means and of wiper means for wiping in the successive portions of a binding tape around the edge of a work piece;

FIG. 6 is a detail view in rear elevation showing the wiper means and their driving connections;

FIG. 7 is a perspective view of the work feeding means and their driving connections;

FIG. 8 is a detail view in rear elevation of the work feeding means;

FIG. 9 is a view in left hand side elevation, partly in section, of the machine;

FIG. 10 is a section along the line XX of FIG. 9;

FIG. 11 is a perspective view of the machine looking from the rear;

FIG. 12 is a fragmentary perspective view of a portion of the structure shown in FIG. 11;

FIG. 13 is a fragmentary view in rear elevation of the mechanism shown in FIG. 12;

FIG. 14 is a detail view, on an enlarged scale, of cement feeding means shown in FIG. 11;

FIG. 15 is a perspective view of aportion of the machine shown in FIG.- 1;

FIG. 16 is a detail view of tape severing means;

FIGS. 17, :18 and 1'9 and detail plan views of mecha- I nism provided for feeding a measured length of binding tape prior to commencing an edge binding operation;

FIG. 20 is a view of the left-hand end of the machine showing the tape wiping and work feeding means in operative relation with an insole;

FIG. 21 is a detail view in rear elevation of a portion of the machine illustrating particularly an arrangement of a guide means for guiding the work piece and for folding the binding tape around the edge of the work piece;

7 FIG. 22 is a schematic view illustrating the attachment of a binding tape around the edge of an insole in the machine provided by the invention; and

FIG. 23 is a wiring diagram of the electrical controls of the machine.

Referring now to the several figures in the drawings, the head of the illustrative machine is supported on a base plate 20 (FIG. 1) to which is secured an upwardly extending post 22 provided with a groove engaged by a member 24 mounted for heightwise movement therein and carrying at its upper end a flat surfaced table 26 which supports the work piece to be operated upon in the machine, herein illustrated as an insole I (see FIGS. 20 and 22). The tape T which is to be adhesively attached around the periphery of the insole to bind the edge thereof is drawn from a reel 28 (FIG. 1) mounted on a bracket 30 secured to a plate 32 constituting a part of the frame of the machine head, and is carried to the point of application in the vicinity of the work supporting table through a first guide member 34, a second guide member 36, and through a nozzle 38 in which, as illustrated in FIG. 22, there are provided a plurality of openings 40 through which adhesive is extruded to coat successive portions of the tape as the latter is progressively advanced toward the insole. The nozzle 38 is formed at the lower end of an inclined casting or carrier 42 forming a part of a thermoresponsive cement melting and dispensing device substantially of the type disclosed in my prior Patent No. 2,765,768, granted October 9, 1956. As further illustrated in FIG. 22, the nozzle 38 is connected by a passageway 44 formed in the casting 42 to a gear pump 46 mounted in the upper end of the casting and driven during an attaching cycle of operation to supply molten cement from a melting chamber provided in a housing 48 supported on the machine frame, into which melting chamber a solid but flexible rod of cement C, of the type disclosed in United States Letters Patent No. 2,867,592, granted January 6, 1959, upon an application of T. C. Morris et al., is fed by means to be described in timed relation to the feed of the work, the cement being drawn from a spool mounted on a bracket 49 secured to the plate 32 (FIG. 1).

The insole and the tape are advanced progressively during an attaching cycle by a pair of frusto

conical rolls

58, 52 which also press the successive coated portions of the tape against the margin of the insole. The rolls are secured respectively to the forward ends of

flexible shafts

54, 56. As best illustrated in FIG. 7, the forward end of the shaft 54 which carries the upper feed roll 50 is journaled in a casting or block 58, the rear end of the shaft being journaled in

brackets

59, 60 extending upwardly from the base plate 20. In the casting 58 is mounted an upwardly extending sleeve or bushing 61 (FIG. slidable in a cylindrical housing 62 having an extension 64 (FIGS. 4 and provided with a slot 65, through which passes a screw 66 by which the housing 62 is adjustably secured to a plate 67 provided on its upper surface with a tongue 68 engaging in a groove formed in the underside of the extension 64. The underside of the plate 67 is likewise provided with a downwardly extending tongue 69 engaging in a groove formed in the upper end of a bracket 70 secured to a post 71 extending from the base plate 20. By the foregoing arrangement, the upper feed roll assembly can be adjusted as a unit to aline the

feed rolls

50, 52 when setting up the machine.

The forward end of the shaft 56 which carries the lower feed roll 52 is journaled in a casting 72 (FIGS. 4, 5 and 7) formed integrally with the member 24 to which the table 26 is secured, the rear end of the shaft being journaled in the bracket 59. The casting 72 is formed integrally with a downwardly extending sleeve or bushing 76 adapted for heightwise movement within the post 22. Within the

bushings

61 and 76 are mounted

compression springs

78, 80 tending normally to urge the

castings

58 and 72 toward each other to bring the

feed rolls

50, 52 together, the force of the springs being adjustable by

screws

82, 84, respectively.

In the rest position of the machine the

feed rolls

50, 52 are maintained separated, against the force of the

springs

78, 80, by an eccentric or cam member 86 (see FIG. 7) engaging the opposite faces of the

castings

58, 72 in which the forward ends of the feed

roll carrying shafts

54, 56 are supported. The member 86 is formed with a shank or spindle 88 rotatably supported in a block 90 fastened to the post 71. On the rear end of the shank 88 is pinned an arm 92 which is pivotally connected by a stud 94 to the upper end of a rod 96, the lower end of which is connected to an arm 98 (FIG. 2) pinned to one end of a rockshaft 100 mounted in a frame 182 secured to a shelf 104 supported between uprights 106 forming part of the lower machine frame. To the opposite end of the rockshaft 100 is pinned another arm 108 to which is pivotally connected the upper end of a rod 110, the lower end of which is connected to a treadle 112 freely mounted on a shaft 114 supported in a frame 116 resting on the floor. The treadle 112 is normally held in elevated position as shown in FIG. 2 by a spring 118 attached at one end to the arm 98 and at its other end to the underside of a bench 120 on which the machine head is supported. The treadle is connected by a twopart rod 122 to a lever 124 which controls a transmission substantially similar to that disclosed in United States Letters Patent No. 2,044,501, granted June 16, 1936, upon an application of P. R. Glass, and comprising a driving pulley 126 mounted on a shaft 128 and connected by a belt 130 to the shaft of an electric motor M, and a driven pulley 132 connected by a belt 134 to a flywheel 136 (FIGS. 1 and 3) keyed to the main drive shaft 138 of the machine. Referring to FIGS. 7 and 8, there is secured to the bracket 70 a plate 140 to which is pivoted at 142 the rear end of an arm 144. The forked forward end of the arm engages a screw 146 threaded into the casting 58 which supports the upper feed roll shaft 54. The arm is formed with a gear segment 148 which meshes with a gear segment 150 on an arm 152 pivotally mounted at its rear end on a pin 154 also projecting from the plate 140, the forward forked end of this arm engaging a screw 156 threaded into the casting .72 which supports the lower feed roll shaft 56. Accordingly, when the treadle 112 is depressed to initiate a binding attaching operation, the cam mernber 86 is rocked in a direction to be disengaged from the castings S8, 72 in which the

roll shafts

54, 56 are supported, whereupon the

springs

78, 80 cause equal and opposite movement of the castings to locate the

rolls

50, 52 in operative position.

The feed rolls 5%), 52 are rotated to feed the work in the following manner:

Referring to FIGS. 3 and 7, the main shaft 138 is journaled in bearings in a bracket 158 fixed to the base 20 and also in the previously mentioned bracket 60. The shaft carries at its inner end a bevel gear 162 in mesh with a bevel gear 164 fast on a shaft 166 rotatably mounted in hearings in a housing 168 fixed to the base 20. A worm 170 on the shaft 166 meshes with a worm gear 172 on one end of a shaft 174 also journaled in bearings in the housing 168. The opposite end of the shaft 174 carries a sprocket wheel 176 connected by a chain 178 to a sprocket wheel 180 on the shaft 54 which carries the upper feed roll 50. Also pinned to the shaft 54 is a gear 182 (FIGS. 4 and 7) which meshes with a gear 184 on the shaft 56 which carries the lower feed roll 52. As the shaft 138 is rotated upon depression of the treadle 112 to start a binding attaching operation, the

shafts

54, 56 are rotated, through the just described train of connec/ tions, in opposite directions to rotate the feed rolls 50, 52 to press the successive portions of the binding tape against the margin of the insole and feed the insole and the attached tape.

Simultaneously with the feed of the work by the

rolls

50, 52 as described, the successive portions of the binding tape T are coated in advance of the point of operation of the rolls with molten thermoplastic cement supplied from the melting chamber in the housing 48, into which the rod cement C is fed in timed relation to the feed of the work. For this purpose the main shaft 138 carries a bevel gear 186 (FIG. 3) meshing with a bevel gear 188 fixed to a transverse shaft 190 journaled in a bracket 191 fixed to the base plate 20. To the rear end of the shaft 190 is secured a disc 192 (see also FIG. 14) provided in its outer face with a groove in which is adjustably fixed a bar 193 having a rearwardly projecting pin 194 engaging in a T-slot 195 formed in the lower end of a connecting rod or pitman 196 (FIGS. 1, 3 and 11), the upper end of which is secured to a oneway clutch 198 carried by a shaft 200 supported in

brackets

202, 204 secured to the machine frame, the shaft carrying also a second one-way clutch 206. The shaft 200 further carries a gear 208 '(FIG. 22) meshing with a gear 210 on a shaft 212 which drives the gear pump 46. On the shaft 212 is fixed a sprocket wheel 214 (FIG. 11) connected by a chain 216 to a sprocket wheel 218 on a shaft 220 journaled in bearings in a casting 222 provided with a tube 224 through which the cement rod C is guided toward the melting chamber in the housing 48 and which is cut away at its upper and lower surfaces to expose the rod for engagement by a pair of

feed Wheels

226, 228, of which the upper Wheel 226 is mounted on the shaft 220. The lower feed'wheel 228 is fixed to a short shaft 230 journaled in one arm 232 of a bell crank lever 234 pivoted at 236 to the casting 222, the upwardly projecting arm 238 of the bell crank having attached to it one end of a spring 240, the other end of which is attached to the casting 222. The lever 234 may thus be swung counterclockwise, as viewed in FIG. 3, to disengage the lower feed wheel 228 from the upper wheel 226 when the rod of cement C is threaded into the machine. A compression spring 242, coiled about a threaded rod 244 rotatable within the shaft 220, is adjustable bymeans of a knurled knob 246 on the rod to vary the friction of a slip clutch (not shown) interposed between the sprocket 218 and the feed wheel 226 to prevent breakage in case the machine is started before the cement has been sufficiently melted. To the shaft 212 is secured a gear 248 (FIG. 11) meshing with a gear 250 on a shaft 252 journaled in the housing 48 of the cement melting unit and carrying a heated disc 254 (FIG. 22), around the periphery of which the rod of cement C is conveyed to the melting chamber in the housing to reduce it to flowable state, as more fully described in my previously cited prior Patent No. 2,765,768.

Referring to FIG. 14, a lever 256 pivoted to the machine frame carries at its upper enda roll 25 7. At its lower end the lever is connected by a spring 258 to the plunger 259 of a solenoid 260 (FIGS. 11, 12 and 22) supported on the base plate 20. Referring to 'FIG. 2, an arm 261 is freely pivoted on the forward end of the arm 98 which is pinned to the rockshaft 100 and to which is connected the treadle rod 96, the said arm 261 resting against a pin 263 (FIG. 2) projecting from the arm 98. When the treadle 112 is depressed to start a binding attaching operation and the shaft 100 is rocked clockwise, as viewed in FIG. 2, the arm 98 is rocked in the same direction and the curved tip of the arm 261 trips a self-opening microswitch 262 supported on the shelf 102, momentarily closing the microswitch. Closing of the microswitch energizes the coil of a relay K1 (see FIG. 23), closing relay contacts KIA and KIB, the closure of the contacts K1B acting to complete a holding circuit, so that the microswitch 262 may open immediately after the tip of the arm 261 has moved past it. Closing of the relay contacts energizes the solenoid 260, whereupon the solenoid plunger 259 is pulled to the right of FIG. 14 and, through the spring 258, swings the lever 256 counterclockwise. The roll 257 carried by this lever then engages the lower end of the connecting rod 196 and moves it upward into a position in which the stud 194 engages the lower end of the T-slot 195 provided in the rod to render the rod effective to impart intermittent movement to the clutch 198 to which it is connected at its upper end, so as to rotate the

feed wheels

226, 228 to feed rod cement into the melting chamber, as well as the melting disk 254 and the gear pump 46 to supply molten cement to the nozzle 38 for coating the successive portions of the tape in timed relation to the rotation of the work feed rolls 50, 52. The quantity of cement fed at each turn of the clutch 198 may be varied according to specific requirements by adjustment of the bar 193 relative to the disk 192 so as to vary the eccentricity of the stud 194 and hence the throw of the connecting rod 196. When, at the end of an operating cycle, the treadle 112 is released and the arm 98 is rocked counterclockwise with reference to FIG. 2, the arm 261, on contacting the microswitch 262, will swing clockwise about its pivotal connection to the arm 98, without actuating the microswitch.

Closing of the relay contacts KIA and KIB (FIG. 23)

also'energizes a solenoid 264 (FIGS. 3,22 and 23) supported on the machine frame and having its plunger 266 connected to the rear end of a lever 268 (see also FIGS.

' 1 and 11) pivoted about midway of its length on a pin 270 mounted in lugs 272 projecting from the machine frame. The bifurcated forward end of the lever 268 engages the upper end of a Bowden wire 274 between a first collar 276 pinned to the wire and a spring 278 bearing at its upper end against a second collar 280 pinned to the Bowden wire. The lower end of the Bowden wire is connected to a block 281 [fast on the upper end of the stem 282 of a valve 284 (FIG. 22) in the nozzle 38. As the solenoid 264- is energized by the closing of the switch 262, the lever 268 is caused to pivot counterclockwise upward, as seen in FIGS. 1, 11 and 22 (or clockwise as seen in FIG. 3), pulling the wire 274 upward, thereby rotating the valve stem 282 clockwise, as viewed in FIG. 22, to open the valve 284 so as to permit molten cement to be extruded through the nozzle openings 40 to coat the tape advanced through the nozzle 38. In the event that the cement in the nozzle has not been melted to a sufiicient degree of fluidity, upward swinging movement of the lever 268 will merely compress the spring 278 without operating the valve, thereby preventing breakage of the parts.

Theattachment of a binding tape to the edge of an insole usually begins at the shank portion at one side of the insole and proceeds around the periphery to the starting point, where the trailing end of the tape is severed by mechanism to be described, which operates near the point of emergence of the tape from the guide member 36, that is, between this member and the nozzle 38. Before beginning the attachment of binding tape to a succeeding insole it is necessary to feed a length of rape through the nozzle 38 to insure the presence of freshly coated tape for attachment to the first portion of the insole. For this purpose the following arrangement has been provided:

Referring to FIGS. 1, 3, 15 and 22, the tape guide member 34- is secured to a bar 286 adapted for endwise movement in a channel provided in the tape guide member 36. The last-named member is formed with forwardly projecting spaced

parallel ribs

288, 290 provided with longitudinal alined slots 292 (FIGS. 3 and 15) which receive a pin 294 extending downwardly through an L-shaped finger 296 (see FIGS. 17, 18 and 19) arranged to engage the tape guided by the bar 286 and maintain it firmly thereagainst as the bar is moved through the guide member 36 to advance a length of tape toward the insole supported on the table 26. The

finger 296 extends in the space between the ribs 288,.

290 from the rear face of a block 298 movable lengthwise of the machine in contact with the edge faces of the ribs to cause the finger to move with the tape guide bar 286. For thus moving the block 298 with the finger 296, there is mounted in the block 298 a forwardly projecting pin 300 on which is mounted the left end of an adjustable connecting rod .302 passing through a forwardly projecting arm 303 of an L-shaped bracket 384 secured at its right hand end to the guide member 34. The right hand end of the connecting rod 302 is mounted on a pin 306 projecting from the upper end of an arm 308 pinned at its lower end to the forward end of a transversely extending rockshaft 310 journaled in bearings in brackets 312, 314 (FIG. 11) secured to the base plate 20. To the rearv end of the shaft 310 is fixed an arm 316 connected by a rod 3-18 to a treadle 320 '(FIG. 2) rotatably mounted on the shaft 114. Depression of the treadle 320 rocks the shaft 310 and with it the arm 308 counterclockwise, as viewed from the front of the machine (FIGS. 1, 15 and 22), whereby the connecting rod 302, the bracket 304, the guide member 34, the guide bar 286, the block 298, and the finger 296 are moved toward the left to advance a length of tape through the guide member 36 and through the nozzle 38 7 to the point of application to an insole on the table 26.

As best illustrated in FIGS. 17, 18 and 19, there are threaded on the connecting rod 302, on either side of the arm 303 of the L-shaped bracket 304, nuts and check

nuts

321, 322. The nut and check nut 322 to the right of the arm 303 are slightly spaced from this arm to provide lost motion between the time the connecting rod 302 is first moved by depression of the treadle 32% and the time when the finger 296 begins to move forward in contact with the tape. As a result of this lost motion the first effect of forward (or leftward) movement of the connecting rod 302 is to cause the finger 296 to pivot inward clockwise, as viewed in FIG. 18, about the pin 294 to engage the tape and maintain it firmly against the guide bar 286. Thereafter, as the connecting rod continues its forward movement, the nut 322 engages the arm 303 of the bracket 304 and moves the latter forward, or to the left, thereby causing the guide member 34 and the guide bar 286 to move in the same direction to advance the length of tape through the guide 36 and the nozzle 38.

The length of the tape advanced by the means just described is determined by an adjustable stop screw 323 (FIGS. 11, 12 and 13) threaded through the arm 316 and engaging a block 324 secured to the base plate 20, to limit counterclockwise movement of the arm 303. Swinging movement of the arm 308 in clockwise direction is limited by a second stop screw 326 (FIGS. 11, 12 and 13) threaded through the arm 3116 with the block 324. A spring biased clamping member 327 (FIGS. 17- 19) mounted between the exit end of the guide member 36 and the entrance to the nozzle 38 holds the tape against backward movement during the retractive movement of the finger 296.

As the tape is advanced through the guide 36 and the nozzle 38 toward the insole in the manner above described, the rod cement is caused to be fed into the melting chamber in the housing 48 and molten cement is delivered to the nozzle, the valve 284 being opened to permit the cement to be extruded through the nozzle openings 40 to coat the tape for attachment to the first portion of the insole edge. For this purpose there is pivotally connected to the arm 316 the lower end of a rod 328 (FIGS. 1 and 11) the upper end of which is provided with a vertical slot 330 through which extends a pin 332 projecting from the clutch 206 on the shaft 200. To the outer end of the pin 332 is attached the upper end of a tension spring 334, the lower end of which is attached to a lug 336 on the base plate 20. As the treadle rod 318 is moved downward by depression of the treadle 320 to feed a measured length of tape and the arm 316 on the shaft 310 is rocked clockwise, as viewed in FIG. 11, the connecting rod 328 is moved down and, through the clutch 206, rotates the shaft 200 to rotate the rod

cement feed wheels

226, 228, the gear pump 46, and the melting disk 254. At the same time the solenoid 264' (FIG. 3) which, as previously explained, is connected through the lever 268 and the Bowden wire 274, to the valve stem 282, is energized to open the valve 284. The solenoid is energized when. a switch 338 (FIGS. l1, l2 and 23) is operated by a link 340 connecting the switch arm to one end of an arm 342, the other end of which is provided with a notch engaging a pin 344 (FIG. 13) mounted in the upper end of a pair of spaced

parallel blocks

346, 348 secured to the shaft 310. The arrangement is such that, as the shaft 310 and the arm 316 are rocked clockwise, with reference to FIGS. 11, 12 and 13, the connecting rod 328 is moved downward and rotates the clutch 206 clockwise until stopped by engagement with an adjustable stop screw 3S0 threaded into the upper end of a bracket 352 extending upward from a bracket 354. After engagement of the clutch 206 with the stop screw, the spring 334 yields to permit further downward movement of the rod 328 without causing further supply of rod cement. By adjustment of the stop screw 350 in the bracket 352, the extent of clockwise movement of the clutch 206 may be variably determined to vary the quantity of cement extruded through the nozzle 38 to coat the tape. Upon continued depression of the treadle 320, after engagement of the clutch 206 with the stop screw 350, the rod 328 is moved further downward, until an abutment screw 356 threaded through a projecting portion of the block 348 engages the arm 342 and disengages it from the pin 344, whereupon a spring in the switch 33% moves the arm 342 to the left of FIG. 13 to reopen the switch, thereby to deenergize the solenoid 264 and close the valve 284 to prevent further extrusion of cement until the operator is ready to start a binding attaching cycle by depressing the starting treadle 112. A spring 358 (FIG. 2) stretched between the twopart rod 318 and the bench 128 returns the treadle 320 to its normal elevated position when released by the operator.

From the guide 36 the tape is moved past the openings 46 provided in the rear face of the nozzle 38, in which face there is also provided a groove 359 (see FIGS. 9 and 20) for receiving the tape guide finger 296. As it emerges from the nozzle 38, the tape is moved toward a folder 360 located adjacent to the entrance side of the feed rolls 5t 52 just above the work supporting table 26, the tape moving toward the folder in yielding contact with a guide member 362 (see also FIGS. 1 and 9) pivoted at its upper end for swinging movement in a vertical plane on a transverse pin 363 mounted in a bracket 364 secured to the casting or nozzle carrier 42'. A tension spring 365 attached at one end to the bracket 364 and at its other end to the guide member 362 normally maintains this member against an abutment screw 366, which is threaded through the bracket and which may be adjusted to vary the spacing of the lower end portion of the guide member from the nozzle 38. The folder 360, which is provided with a U-shaped throat by which the tape is partially folded to prepare it for application to the opposite faces of an insole supported on the table, is attached to the forward end of a rod 367 (FIGS. 9, l0 and 21) mounted in a block 363 pivoted for limited yielding movement about a vertical axis on a stud 369 threaded into a bracket 370 fixed to the post 22. A tension spring 371 attached at one end to a screw 372 extending from the post 71 and and at its other end to a screw 373 projecting from the block 368 permits the tape folder 360 to yield in response to the pressure of the insole as it moves past it in the course of a binding attaching operation, the block pivoting about the stud 369 in clockwise direction, as seen in FIG. 21, the extent of such movement being determined by engagement of a stop screw 374 threaded through the block with the downwardly extending arm of a bracket 375, in the shape of an inverted L, fixed to the bracket 70 and having a horizontal arm formed at its forward, or right hand end with an edge gage member 376 against which the sole is maintained to guide it during a binding attaching operation.

As the coated tape progressively passes over the throat of the folder 360, it is wiped inwardly of the insole edge against the upper and lower surfaces of the insole by a pair of fingers 378, 380 (FIGS. 4, 5, 6 and 22) which are mounted at their rear ends on

eccentric pins

382, 384, projecting respectively from meshing

gears

386, 388 carried by

shafts

390, 392 rotatably mounted in a bracket 394 extending from the base plate 20. The gear 388 also meshes with a gear 396 carried by a shaft 398 journaled in

brackets

400, 401 extending upwardly from the base 20. A sprocket 402 on the shaft 398 is connected by a chain 484 to a sprocket 406 (FIGS. 3, 15 and 22) on the shaft 166 which is driven from the main shaft 138 through the transmission described earlier, whereby the

wiper fingers

378, 380 are operated in timed relation to the operation of the work feeding rolls 50, 52 and the cement feeding means which are also driven from the main shaft. The

fingers

378, 380 are interconnected by a spring 408 attached at its lower end to a downwardly extending portion 412 of the finger 388, and at its upper end to a split sleeve 416 straddling an upwardly projecting portion 418 of the finger 378. A screw 413 threaded into the sleeve 416 permits adjustment of the sleeve relative to the portion 418 of the finger 378' to vary the action of the spring 408.

The forward end portions of the

wiper fingers

378, 380 are supported, with provision for limited heightwise movement, in brackets 420, 422 (see FIGS. 4 and 5) respec-. tively secured by screws 423 to the

castings

58, 72 which support the forward ends of the

shafts

54, 56 which carry the feed rolls 50, 52 so as to move with these toward the insole supported on the table 26 when the starting treadle 112 is depressed to begin an attaching operation. Each of the

brackets

420, 422 may be adjusted heightwise relative to the casting to which it is secured so as to vary the path in-which the wiper fingers shall operate'with relation to the plane of the insole. For this purpose each of the brackets is provided with a slot which receives an eccentric stud 424. After loosening the screws 423 securing each of the

brackets

420, 422, the eccentric stud in either of the brackets may be rotated in either direction to raise or lower the bracket relative to the other bracket, thereby to locate the'forward end portions of the wiper fingers closer to or farther from the insole.

While the insole is fed along the table 26 during a binding tape attaching operation, it is held firmly against the table and guided thereon by a holddown member 426 (FIGS. 1 and 20), in the form of a knurled wheel which engages the insole inward of the margin to which the tape is attached, slightly in front of the tip of the upper feed roll 50, and biases the insole toward the edge gage 376. The wheel 426 is rotatable on a shaft 428 supported in a holder or block 430 secured by a screw 431 to an arm 432 which is pivoted at one of its ends for limited heightwise swinging movement on a stud 434 in the lower bifurcated end of a block 436 which is fixed at its upper end to a bracket 438. The opposite end of the arm 432 is connected to the bracket 438 by a screw 43? extending through a slot in the bracket. The bracket 438 is secured to the casting 58 which carries the upper feed roll 50, whereby the wheel 426 can move with the roll 59 toward and away from the insole. A compression spring 440 interposed between the arm 432 and a washer on the lower end of a screw 442 extending through the bracket 438 tends normally to urge the arm 432 and the wheel 426 in a downward direction, but permits it to yield upwardly when the wheel 426 rolls in contact with a thicker portion of the insole, downward pivotal movement of the arm being limited by engagement of the head of the screw 439 with the bracket 438. The friction of the wheel 426 is adjustable by means of a compression spring 445 mounted on the shaft 428 and bearing against one end of a bushing 446 loose on the shaft, the other end of the.

bushing bearing against the outer face of the wheel 426. The compression of the spring 445 is adjustable by means of locknuts 447, 448 threaded on the outer end of the shaft 428. Further, by loosening the screw 431, the block 430 may be turned a few degrees to vary the angle of the wheel 426 with relation to the line of feed of the insole, so that it will operate in the most efficient manner to guide the insole against the edge gage 376 so as to insure attachment of the binding tape at a uniform distance from the insole edge.

When a binding tape attaching operation reaches a point on the insole substantially corresponding to the starting point, the operator actuates a knee lever 450 (FIGS. 2 and 23) to close contacts 4520 and 452d of a switch 452 mounted on the shelf 104, thereby energizing an electric circuit controlling a solenoid 454 (FIGS. 11, 22 and 23) supported on the bench 120. The plunger 456 of the solenoid is connected by a rod 458 to the lower end of a bar 460 pivoted about midway its length on a pin 462 in a block 464 secured to the underside of the base the tape.

10 plate 20. At its upper end portion the bar 460 is pivotally connected by a pin 466 to one end of a transverse rod or bar 468 to the opposite end of which is pivotally secured by a pin 470 an upwardly extending knife 472 (FIGS. 16 and 22) pivoted on a pin 474 to a block 476 secured to the top of the base plate 20. The knife 472 .has a blade 478 which cooperates with a shear member 480 also mounted on the pin 474 to sever the tape. A spring 482 connected at one end to the bar 468 and at its opposite end to a lug 484 on a plate 486 secured to the block 476 return the knife to its inoperative position, as determined by engagement of the bar 468 with a stop s'crew 488 extending through the plate 486. 4

The switch 452, which is closed by the operation of the knee lever 450, controls the holding circuit for the relay K1 which, as previously explained, is energized by depression of the starting treadle 112 to energize the solenoid 264 thereby causing the valve 284 to be opened for extruding cement through the nozzle openings 40. In consequence of this connection, when the switch 452 is operated to close the contacts 4520, 452d in the previously described manner to operate the knife solenoid 454, the contacts 452a, 452b are opened to break the holding circuit through the relay K1, thereby deenergizing the solenoid 264 and causing the valve 284 to be closed to stop further extrusion of cement.

As earlier explained, before beginning a tape attaching operation the treadle 320 is depressed to operate the tape guiding means to feed a measured length of tape, the guide bar 286 being moved forwardly, or to the left of FIG. 3, within the guide members 36. To prevent inadvertent operation of the tape severing knife 472 at this time and thus avoid the possibility of breakage of the knife, the following arrangement has been provided. Referring to FIGS. 12 and 13, on the pin 344 mounting the arm 342 is mounted the rear end of an arm 490 the forward end of which is normally in engagement with the button 492 ofa self-opening microswitch 494 supported on the base plate 20 and connected in the circuit for the knife actuating solenoid 454 in series with the switch 452. When the treadle rod 318 is moved down by depression of the treadle 320, the arm 490 is swung clockwise, as seen in FIGS. 12 and 13, to disengage it from the switch button 492 and allow the switch 494 to open, thereby opening the circuit, so that the solenoid 454 cannot be energized by closing of the contacts 4520, 452d of the switch 452 through inadvertent operation of the knee lever 450.

The operation of the machine to effect the attachment of a binding tape to the edge of an article, such as the insole I shown in FIGS. 20 and 22, will now be summarized.

It will be assumed that the main power switch MS (FIG. 23) has been closed to supply power and operate the motor M, a switch 496 (FIG. 1) turned on to supply current to heating elements in the cement melting unit or housing 48, the nozzle carrier or casting 42, and the nozzle 38, arheostat 498 set for the desired temperature. The operator will first depress the treadle 320 (FIG. 2) to cause the means comprising the tape guide sliding bar 286 (FIGS. 1, 15, l7, 18, 19 and 22), the connecting rod 302, and the arm 308 to feed a measured length of tape through the guide 36 and the nozzle 38 toward the throat of the folder 360 for attachment of the leading end of Depression of the treadle also causes the bar 328 (FIGS. 1, 11 and 22) which is connected to the arm 316 on the shaft 310 and to the clutch 206 to be moved downward so as to rotate the clutch 206 and the shaft 200 to rotate the

feed wheels

226, 228 to feed a length of rod cement C into the melting chamber provided in the housing 48, from which the molten cement is supplied by the gear pump 46 down the passageway 44 in the casting 42 leading to the nozzle 38. As the shaft 310 is rocked counterclockwise, as viewed in FIG. 22, the

link 340 closes the switch 338 (FIGS. 11, 12, 22 and 23),

spa es? whereby the solenoid 264 (FIGS. 3, 22 and 23) is energized to cause the valve 284 to be opened to admit cement to the nozzle, so that the measured length of tape may be coated as it moves in contact with the orifices 40 in the nozzle. As soon as a supply of cement, determined by engagement of the clutch 2% with the adjustable stop screw 35% (see FIG. 11), has been fed into the nozzle, the switch 338 is automatically reopened and the solenoid 264 deenergized, whereby the valve 284 is closed to shut otf further supply of cement to the nozzle until the operator is ready to set the machine in operation to perform an attaching cycle. When the operator releases the treadle 32th, upward movement of the bar 328 to its inoperative position stops further supply of rod cement into the melting unit.

The operator next places an insole on the table 26, with the edge of the insole in contact with the tape within the throat of the tape folder 366. He then depresses the treadle 112 (FIGS. 2 and 22) whereby the tape pressing and feeding rolls 59, 52 are moved into engagement with the tape at the opposite surfaces of the insole, and the driving pulley 126 is connected to the driven pulley 132 to rotate the main shaft 138 which drives the rod cement feed wheels 226, 223, the melting disk 254 in the housing 48, the gear pump 46, as well as the

wiper fingers

378, 38%) and the work feed rolls 50, 52. As the treadle 112 is depressed, the arm 261 contacts the microswitch 252 (FiGS. 2 and 23) and by momentarily closing the switch energizes the coil of the relay K1 and closes the relay contacts K1A and K143, the switch then being automatically opened again. Closing of the relay contacts Kl-A and Kl-B completes a holding circuit for the relay through the closed switches 450 and 494- to energize the solenoid 26%, whereby the connecting rod 196 (FIGS. 3, 11, 14 and 22) is moved into position to rotate the clutch 198 through which the rod

cement feed wheels

226, 228 are controlled to feed cement into the melting unit, and also to energize the solenoid 264 to cause the valve 284 to be opened to admit molten cement to the nozzle 38.

When the binding attaching operation reaches a point substantially corresponding to the point of attachment of the leading end of the tape, the operator actuates the knee lever 450 (FIGS. 2 and 23), causing the switch 452 to be moved away from contacts 452a, 452b, that is from the position shown in FIG. 23, to the left and into engagement with contacts 452e, 452d, to energize the solenoid 454 which operates the knife 4'72 (FIGS. ll, 16 and 22) to sever the tape. Movement of the switch 452 away from the contacts 452a, 4521) opens the holding circuit for the relay, whereby the relay contacts Kl-A and KLB are opened and the

solenoids

260, 264 are deenergized to stop further feed of rod cement into the melting unit and to close the valve 284 so as to shut off further supply of molten cement to the nozzle.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a tape applying machine, an adhesive reservoir; adhesive applying means to which adhesive is supplied from the reservoir to coat successive portions of a tape as the tape is progressively moved past the applying means;

means including a valve controlling the supply of adhesive from the reservoir to the applying means; means to press the successive coated portions of tape against a work piece and to feed the tape and the work piece; means to operate the pressing and feeding means; operator-controlled means to actuate the operating means to initiate an operating cycle and simultaneously to open the valve; tape severing means; and means to actuate the tape severing means and simultaneously to close the valve.

2. A machine for progressively coating a binding tape with adhesive and for attaching it to a work piece in a continuous operation comprising, in combination with a work support, a reservoir for a supply of adhesive, means for progressively feeding adhesive to the reservoir, and

12 applying means to which adhesive is supplied from the reservoir to coat successive portions of the tape as they are progressively moved past the applying means, means including a valve for controlling the supply of adhesive to the applying means; valve operating means for alternately opening and closing the valve; means to press the successive coated portions of tape against the work and to feed the Work and the tape; power means to operate the adhesive feeding means and the tape pressing and feeding means; starting means to initiate operation of the power means; a first solenoid to actuate the valve operating means; a second solenoid to actuate the adhesive feeding means; a switch closed and immediately opened by actuation of thestarting means; a relay energized by the closing of said switch to energize said first and second solenoids; a holding circuit closed by the energization of said relay to maintain said solenoids energized after the opening of said switch; tape severing means; a third solenoid to actuate said severing means; and a switch to energize said third solenoid and simultaneously to open said holding circuit to deenergize said first and second solenoids.

3. A machine for progressively coating a binding tape with adhesive and for attaching it to a work piece in a continuous operation comprising, in combination with a work support, a reservoir for a supply of adhesive, means for progressively feeding adhesive to the reservoir, and applying means to which adhesive is supplied from the reservoir to coat successive portions of the tape as they are progressively moved past the applying means, means including a valve for controlling the supply of adhesive to the applying means; valve operating means for alternately opening and closing the valve; means to press the successive coated portions of tape against the Work and to feed the work and the tape; power means to operate the adhesive feeding means and the tape pressing and feeding means; a driving connection between the adhesive feeding means and the power means; starting means to actuate the power means to initiate an operating cycle; means actuated by operation of the starting means to render the driving connection operative to drive the adhesive feeding means and simultaneously to actuate the valve operating means to open the valve; tape severing means; and means to actuate the severing means and simultaneously to render the driving connection between the adhesive feeding means and the power means inoperative and to actuate the valve operating means to close the valve.

4. A machine for progressively coating a binding tape withadhesive and for attaching it to a work piece in a continuous operation comprising, in combination with a work support, a reservoir for a supply of adhesive, means for progressively feeding adhesive to the reservoir, and applying means to which adhesive is supplied from the reservoir to coat successive portions of the tape as they are progressively moved past the applying means, means including a valve for controlling the supply of adhesive to the applying means; valve operating means for alternately opening and closing the valve; means to press the successive coated portions of tape against the work and to feed the work and the tape; power means to operate the adhesive feeding means and the tape pressing and feeding means; a driving connection between the adhesive feeding means and the power means; a first solenoid for actuating the driving connection; a second solenoid for actuating the valve operating means; a switch controlling both solenoids; starting and stopping means to actuate the power means; means associated with the starting and stopping means for actuating the switch to energize said first and second solenoids to render the driving connection operative to drive the adhesive feeding means and to cause the valve operating means to open the valve; tape severing means; a third solenoid to actuate the severing means; and a switch to energize said third solenoid and simultaneously to deenergize said first and second solenoids.

5. In a tape applying machine, an adhesive reservoir;

so... have var-V 13 adhesive applying means to which adhesive is supplied from the reservoir to coat successive portions of a tape as the tape is progressively moved past the applying means; means including a valve for controlling the supply of adhesive from the reservoir to the applying means; means to press the successive coated portions of tape against a work piece and to feed the tape and the work piece; means operating in advance of the pressing and feeding means to wipe the successive coated portions of tape inwardly over the edge of the work piece and against the opposite surfaces thereof; means to operate said wiping means and said pressing and feeding means; starting means to actuate said operating means to initiate an operating cycle and simultaneously to open the valve; tape severing means;

and means to actuate the severing means and simultaneously to close the valve.

6. A machine for progressively coating a binding tape with adhesive and for attaching it to a work piece in a continuous operation comprising, in combination with a work support, a reservoir for a supply of adhesive; means for progressively feeding adhesive to the reservoir, and applying means to which adhesive is supplied from the reservoir to coat successive portions of the tape as they are progressively moved past the applying means; means including a valve for controlling the supply of adhesive to the applying means; valve operating means for alternately opening and closing the valve; a pair of rolls to press the successive coated portions of tape against the opposite surfaces of the work piece and to feed the tape and the work piece; carriers for the rolls; spring means to move the carriers relatively to move the rolls into operative position; means normally maintaining the carriers separated against the force of the spring means; a pair of parallel wipers supported on the carriers for movement with the rolls toward and away from the work-support to wipe the successive coated portions of tape inwardly over the edge of the work piece and against the opposite .faces thereof in advance of the pressing and feeding rolls; power operated means to drive the adhesive feeding means, the pressing and feeding rolls and the wipers in timed relation; eccentric driving connections between the wipers and the power operated means to impart movement to the wipers in elliptical paths; spring means interconnecting the wipers for conjoint movement; starting means to actuate the power operated means; and a connection in the starting means to move the means which maintain the carriers for the rolls and the wipers separated to a position to release the carriers to the action of the spring means to move the rolls and the wipers into operative positions.

7. The machine of claim 6, in which means is provided for heightwise adjustment of the wipers so as to vary their plane of operation relative to the plane of the work piece.

8. The machine of claim 6, in which the spring means interconnecting the wipers is adjustable to vary the pressure of the wipers on the work.

9. In an insole edge binding machine, a support for an insole; a reservoir for a supply of cement; means for progressively feeding a solid rod of thermoplastic cement to the reservoir; heating means within the reservoir to melt the cement; a nozzle to which molten cement is supplied progressively to coat successive portions of a binding tape as the tape is progressively drawn past the nozzle; means including a valve to control the supply of cement from the reservoir to the nozzle; means including a solenoid for actuating the valve and a switch to energize the solenoid; a pair of applying rolls operative to press the coated tape against the opposite surfaces of the insole; power driven means to operate the cement feeding means and the applying rolls; a driving connection between the cement feeding means and the power driven means; means including a solenoid to cause the driving connection to operate the cement feeding means; operator-controlled means to actuate the power driven means and simultaneously to operate including a solenoid to operate the knife; and a switch the operation of which energizes the knife operating solenoid and simultaneously deenergizes the valve actuating solenoid and the solenoid which controls the operation of the cement feeding means.

' 10. In a tape applying machine, a reservoir; means-for feeding adhesive to the reservoir, adhesive applying means to which adhesive is supplied from the reservoir to coat successive portions of a tape as the tape is pro gressively moved past the applying means; means including a valve for controlling the supply of adhesive from the reservoir to the applying means; means to press the successive coated portions of tape against a work piece and to feed the tape and the work piece; 'means to feed initially a measured length of tape past the coating means and toward the pressing and feeding means; means to actuate said tape feeding means; a connection between the actuating means and the adhesive feeding means to operate the last named means to supply adhesive to the adhesive applying means; and means operated by the actuating means to open the valve and to close it after the supply of a determined quantity of adhesive.

11. The machine of claim 10, in which the tape feeding means includes a reciprocating guide member movable toward and away from the tape pressing means, a pivoted finger engageable with the tape to hold it against the guide member during the movement of this member to advance the tape, and a lost motion connection in the tape feeding means effective to cause the finger to swing into engagement with the tape before the guide member is moved to advance the tape.

12. The machine of claim 10, in which other means is provided to hold the tape against retractive movement during the return of the guide member to its starting position.

13. In a tape applying machine, an adhesive reservoir; adhesive applying means to which adhesive is supplied from the reservoir to coat successive portions of a tape as the tape is progressively moved past the applying means; means including a valve for controlling the supply of adhesive from the reservoir to the applying means; means topress the successive coated portions of tape against a work piece and tofeed the tape and the work piece; means to feed initially a measured length of tape past the coating means and toward the pressing and feeding means; means to actuate said tape feeding means; a connection between the actuating means and the adhesive feeding means to operate the feeding means to supply adhesive to the applying means; means operated by said actuating means to open the valve and to close it after the supply of a determined quantity of adhesive; a knife to sever the tape at the end of a binding attaching operation; and means operated by the actuating means to prer vent operation of the knife during the feeding and coating of the measured length of tape.

14. A machine for attaching binding tape to a Work piece having an adhesive reservoir; means for progressively feeding adhesive to the reservoir; an applicator nozzle to which adhesive is supplied from the reservoir to coat successive portions of tape; a valve controlling the supply of adhesive to the nozzle, and means to press the successive coated portions of tape against the work piece, in combination with means for initially feeding a measured length of tape past the nozzle and toward the tape pressing means; means to actuate the tape feeding means; a solenoid to operate the valve; a microswitch closed by operation of the actuating means to energize the solenoid and cause the valve to be opened; a connection between the actuating means and the adhesive feeding means to operate said adhesive feeding means; and a lost motion arrangement in said connection effective 15 to open the microswitch and deenergize the solenoid to close the valve after the supply of a determined quantity of adhesive to coat the measured length of tape.

15. The machine of claim 14 in which adjustable means is provided for variably determining the time when the lost motion arrangement becomes effective to open the microswitch and close the valve, thereby to vary the quantity of adhesive supplied to the nozzle.

16. A machine for attaching binding tape to a work piece having an adhesive reservoir; means for progressively feeding adhesive to the reservoir; an applicator nozzle to which adhesive is supplied from the reservoir to coat successive portions of tape; a valve controlling the supply of adhesive to the nozzle; and means to press the successive coated portions of tape against the work piece, in combination with means for initially feeding a measured length of tape past the nozzle and toward the tape pressing means; means to actuate the tape feeding means; a solenoid to operate the valve; a microswitch closed 'by operation of the actuating means to energize the solenoid and cause the valve to be opened; tape severing means; a solenoid to actuate the severing means; a switch the closing of which energizes the solenoid; a microswitch connected in series with said switch; a member connected to the means which actuates the tape feeding means and engageable with the microswitch to hold it closed, said member, when moved out of engagement with the microswitch upon operation of said actuating means to feed a measured length of tape, permitting the microswitch to open, thereby rendering the first-named switch ineflective to energize the solenoid during the feed of the measured length of tape.

References Cited in the file of this patent UNITED STATES PATENTS 2,651,793 Tenge Sept. 15, 1953 2,979,744 Clark Apr. 18, 1961 2,984,848 Small May 23, 1961