US2892199A - Work supports for shoe machines - Google Patents

Description

June 5 Q BQJ. M. MURPHY 2,

woRk SUPPORTS FOR SHOE MACHINES Filed Dec. 27, 1956 v I GYSheetS-Sheet 1 g m w '5 F Inventor Brian J M Murphy June 30, 1959 B. J. M. MURPHY WORK SUPPORTS FOR SHOE MACHINES 6 Sheets-Sheet 2 Filed Dec. 27, 1956 June 30, 1959 B. J. M. MURPHY 2,892,199

I WORK SUPPORTS FOR-SHOE MACHINES Filed Deer 27, 195s v v e Sheets-Sheet 3 [fir/en tar Brian J M Murphy B3 is neg June 30, 1959 B. J. M. MURPHY WORK SUPPORTS FOR SHOE MACHINES 6 Sheets-Sheet 4 Filed Dec. 27, 1956 Invenzar Brian JMMurphy June 30, 1959 B. J. M. MURPHY WORK SUPPORTS FOR SHOE MACHINES 6 Sheets-Sheet 5 Filed Dec, 27, 1956 Inventor Brian M Murphy June 30, 1959 Filed Dec'. 27, 1956 B. J- M. MURPHY WORK SUPPORTS FOR SHOE MACHINES 6 Sheets-Sheet 6 2,892,199 WORK SUPPORTS FOR SHOE MACHINES Brian J. M. Murphy, Leicester, England, assignor to v United Shoe Machinery Corporation, Flemington, NJ.',

' and Boston, Mass., a corporation of New Jersey Application December 27, 1956, Serial No. 630,940

priority, application Great Britain January'G, 1956 i Claims. ch 12-863) This' invention relates toshoemaking machines and more particularly to machines for beveling or trimming I;

theheel end of an insole secured to a last.

e The word shoe where used herein is used generically as indicating outer footwear generally and includes. the article in the course of manufacture and repair.

Therewill hereinafter be described one convenient form curvatures on and about itsv bottom surface. To insure, j

therefore, -a correct size of insole for a particular last it is a. 'common practice initially to-cut the insolejsomewhat longer at its heel end than the dimensionof the last for which it is intended and when the insole has been .tacked to the last, it is then trimmed, to registerpreci'sely with the periphery of the last bottom. It is desirable that the shape of the finished shoe have a smoothcontinuous curve from the upper edge of the shoe at. the heel end to its heel seat portion. For this reason it is frequently desirable to bevel the lower edge of the insole at an angle such that the curve at the back of the last and the contounof the periphery of the insole are substantially continuous, i When the insole is made of leather, it is a relatively Unitcdfitatcs. PfltmtQ I trative machine.

simpleoperation to trim and bevel the edge bythe usev of a rotary cutter. However, in recent years it has become a practice in shoe manufacturing to reinforce insoles 'with hard fibrous substances, resulting in a more difficult task for an operator and'for the cutting tools of machines previously used to trim and bevel leather insoles. Furthermore, difliculty also arises from the fact that the resistance offered by the hard fibrous sub-- stances to the action of the trimming tool or'cutter tends to displace the insole relative to the last bottom in spite of tacks which are inserted to prevent such relative movement. Clamping means for v securing the insole to the last bottom have hitherto been available for this operation but have not ibeenof a nature to hold the insole firmly against such displacement nor have such clamps been convenient to operate, particularly;

when a large range of sizes of shoes are being made,

Accordingly, it is an object of this invention to pro vide a machine for operating on a shoe part mounted on a last, the machine having convenient clamping means against displacement relatively thereto as, the machine operates on the shoe part. Y r

A seeond. object of this invention is to provide a machine for trimming reinforcedinsoles, the machine to the last bottom as the trimming cutter acts on the reinforcing material.

It is-another object of this invention to provide an insole clamping machine which is simple to operate and while able to clamp an insole against a last with ex treme pressure does not require strenuous effort on the part of the operator to effect such clamping. 3 In accordance with the various features of this invention, there is provided an insole trimming machine having a trimming cutter and a hydraulically operated clamping means comprising a first clamp and a second clamp movable relative thereto by pressurized fluid whereby a last with an attached insole may be firmly gripped between said clamps while being presented to the cutting means. Hydraulic operating fluid is supplied to the clamping means from a treadle operated fluid pump comprising piston and cylinder mechanism. In order that variations in pressure of the operating fluid may be compensated for, the piston-cylinder mechanism is provided with adjustable means to permit movement of the cylinder relative to the piston to vary the volume within which the operating fluid is compressed.

In order that the above. and other of the variousob jects of the invention may be made clearer there will now be given'a more detailed description of said illus- It is however clearly to be understood that'the saidrillustrative machine is selected for description merely by way of exemplification of the invention and not by way of limitation thereof.

In the drawings,

Fig. :1 is a front elevation of an insole trimming machine embodyingithe invention; Y I.

Fig. 2 is a side elevation partly in section of hydraulic actuating mechanism forming part of the machine shown in Fig. l;

' Fig. 3 is a plan view of Fig. 2;

Fig. 4 is a plan view of the work clampingv and trimming portion of the machine shown in Fig. 1;

Fig.' 5 is a front elevation partly in section of the mechanism shown in Fig. 4;

Fig. 6.is a plan view partly in section of a guard for the trimming cutter; and

Fig. 7 is a side elevation of the portion of the machine shown in Fig. .4.

The apparatus illustrated in the drawings. is an insole trimming machine adapted to trim and bevel the peripheral portions of an insole secured to a last, the insole and last being firmly clamped together during the trimming operation. Referringto Fig. l, which shows the mechanism shown in the front of the machine as viewed by an operator presenting a shoe thereto, the machine comprises a base 2 with a frame 4 mounted thereon'in which is journaled a horizontally extending shaft 6 that carries the cutting means in the form of a trimming and beveling cutter 8. Connected to the frame 4, by means hereinafter to of sufficient strength to-hold the part against the last A having convenient .work clamping means. of ;sutficient strength to hold the insole against displacement relative be described, is a C-shaped work supporting jack 10 carrying clamping means comprising a first rotatable clamp 12 and a second rotatable clamp 14 movable bodilyrelative thereto.

The second clamp 14 is formed on the end of a spindle constituting a piston movable within a horizontal cylinder which is conected to the upper portion of a flexible pipe 16. The pipe 16 leads, by way of an air return bleed valve 18, to a fluid pump comprising a 7 piston housing 20 located adjacent thebase of the.

machine. The piston housing 20 is mounted in a frame 22 separate from the base 2 and placed on the floor to facilitate its conection to an operator-actuatedtreadle. J, Referring to. Figs 2 and 3, the piston housing 20 which.

is generally cylindrical in form is pivotedon trunnions 24 journaled in opposed arms 26 of a pressure measuring lever 28. The arms '26 of the lever 28 are pivoted on a' Shaft 30 in the left-hand end of the frame 22. The lefthand end of that portion of the machine shown in Figs. 2 and 3, represents the rear of the machine as viewed by the operator and will hereinafter be referred to as such. Mounted on upright brackets 32 on the frame 22 is a Plate 34 which extends widthwise of the frame. The arms 26 ,of the lever 28 are joined at an apex 36 adjacent the plate 34 and a shaft 38 carried in the apex 36 extends outwardly therefrom and has a flat end portion overlying a portion of the plate 34. A cross arm 40 is pivotal- 1y mounted on the shaft 38 adjacent the apex 36. Anchored by hooks 42 in the ends of the cross arm 40 are downwardly extending tension springs 44 connected to the frame 22 by hooks 46. An adjusting screw 47 is threaded in the flattened end of the shaft 38 and engages the top surface of the plate 34 whereby rotation of the screw 47 will pivot the measuring lever 28 about the shaft 30. A lock nut .48 secures the screw 47 in its desired position of adjustment.

A treadle 50 is pivoted on a fulcrum pin 52 in the frame 22 and carries a treadle plate 51 at its forward portion. The distance from the treadle plate 51 to the fulcrum pin 52 is about ten times the distance from the fulcrum pin to the rear end of the treadle. Extending between the brackets 32 of the frame 22 is a cross plate 54 on which is mounted a catch plate 56 having an inclined face 58.

Carried by the treadle 50 is a fulcrum pin 60 on which is pivoted a pair of bell crank levers 62. The lower arms 64 of the lever 62 are connected by a plate 66, having a notch 68 formed therein. The other arms 7.0 of the levers 62 extend toward the right, as seen in Fig. 2, along each side of the treadle 50. Extending upwardly from the righthand end of the arm 70 are brackets 72 and a second treadle plate 74 extends across the bracket 72 bridging the treadle 50. On the left-hand end of the treadle 50 is a pair of downwardly depending lugs 76, one on each side of the treadle. Secured to the lower portion of each of the lugs 76 is one end of a treadle lifting tension spring 78, the opposite end of which is secured to the frame 22 by a hook 80.

Upon depression of the treadle 50, the notch 68 engages the catch plate 56, a compression spring 75 which extends between the treadle plate 74 and the top of the treadle 50 urging the notch 68 into engagement with the plate 56. To release the treadle 50, the treadle plate 74 is depressed, which through the bell crank levers 62, disengages the notch 68 from the catch plate 56, the tension springs 78 then causing the treadle to be raised to its original or rest position. Threaded in the plate 34 is an adjustable stop screw 81 which engages the upper surface of the treadle 50 to determine the extent of move ment of the treadle 58. A lock nut 82 secures the screw 81 in any desired position of adjustment.

Integral with the treadle 50 and extending rearwardly from the'fulcrum 52 is an arm 84 pivotally connected to an upwardly extending piston rod 86 integral with a first or large diameter low pressure piston 88. The piston 88 slides in a cylinder 90 formed in the lower portion of the piston housing 20. Extending axially through the piston 88 and the rod 86 is a bore 92 in which is threaded a screw 94 held adjustably in place by a set screw 96. A spring 98 is compressed between the top of the screw 94 and a valve lifting plug 102 which extends into a recess 104 formed in the top of the piston 88. A flange 105 on the top of the plug 102 restricts its downward movement relative to the piston 88 and an ring 106 in the stem of the plug 102 forms a fluid tight seal with the bore 92. The plug 102 supports a valve seat 110, the upper annular surface of which engages a downwardly extending annular rim 112 formed on a piston cover 114 socured by screws 116 to the head of the piston 88 and holds the valve seat 110 in place in the'recess of the first piston 88.

When the piston 88 is in its lower position, there extends into an opening in the piston cover 114 above the valve seat a substantially vertical plunger 118 which is coaxial with the piston. The upper part of the plunger 118 slides in a sleeve 120 secured by screws 122 to the head of the piston housing 20. The sleeve 120 fits within a cylinder 124 which is formed in the upper part of the piston housing 20 and which is appreciably smaller in diameter than the cylinder 90. The upper end of the plunger 118 is formed with a head providing a second or high pressure piston 126 which rests in its lower position on the upper end of the sleeve 120. Above the head 126 are a sealing ring 128 and a gland 130 secured to the piston 126 by a screw 132 thereby forming a fluid tight seal between the piston and the cylinder 124. A bore 134 extends through the plunger 118 and the screw 132. Fitting in a recess 136 in the head of the screw 132 is a spring 138, the upper end of which fits into a recess 140 formed in a cover 141 fitting the head of the cylinder 124. The spring normally acts to urge the second piston 126 downwardly against the upper edge of the sleeve 120. The recess 140 communicates with a passageway 142 in the cover 141 to which is connected the flexible pipe 16 leading to the clamp 14. At the top of the piston housing 20 and surrounding the high pres sure piston and cylinder is a fluid reservoir 144 having a filler 148. A passageway leads from the reservoir 144 to a channel 152 surrounding the low pressure piston 88. A recess 154 in the piston 88 is in communication with the channel 152 to provide free flow of fluid between the channel, the recess and the reservoir. A passageway 156 communicates with the recess 154 and extends upwardly into the piston 88 and at the upper end of the passageway 156 is located a one-way flow check valve 158 which communicates with an opening formed in the plate 114. The check valve 158 permits the upward flow of fluid from the recess 154 to the upper face of the piston 88 but prevents the downward flow thereof. A passageway 162 communicates with the channel 152 to permit fluid which may have entered the recess 154 to drain away.

The purpose of the above described portion of the illustrated machine is to provide suitable pressure by fluid means to move the clamp 14 (Fig. 1) toward the clamp 12 for clamping a last with an insole attached thereto. To effect this purpose the reservoir 144 is filled with fluid, preferably oil, and the system is filled with fluid until the movable clamp 14 is ready to move under treadle action. Air is released from the system at the air bleed valve 18 (Fig. 1) and fluid is circulated by pumping the treadle 50.

In order to operate the machine, the treadle 50 is depressed a small amount causing the piston rod 86 and consequently the first or low pressure piston 88 to rise within the cylinder 90. This action forces fluid through the passageway in the second or high pressure piston 126 and through the flexible pipe 16 against the clamp 14 (to be described in more detail hereinafter) causing the second clamp 14 to be moved toward the first clamp 12,

the amount of movement depending on the size of the last being used. Further depression of the treadle causes the valve seat 110 to engage the bottom of the plunger 1-18 thereby shutting off the further flow of fluid through the passageway in the piston 126. The high pressure piston 126 then rises with the lowpressure piston 88 and builds up pressure above it causing a column of liquid in the pipe 16 to act at a high pressure against the clamp 14 which with the clamp 12 firmly grips the last with the insole attached to it.

The tension springs 44 are set to hold the pressure measuring lever 26, on which the piston housing 20 is mounted, in its, lowermost position until the upward thrust of the pistonreaches a predetermined pressure which remains constant for .all thicknesses of last and insole. When the action of the treadle .50 causes the '5 high 'andlow pressure pistons to' exert a pressure in excess of the force exerted by the tension springs, the pressure measuring lever 28 and thus the piston housing 20 pivot upwardly about the fulcrum 30 against the action of the springs 44. The excess pressure of the pistons over the force of the springs is neutralized by the upward movenient of the piston housing, the pistons inside the housing then ceasing to move relative to the housing and-thus the last with the insole attached may be clamped at a constant predetermined pressure notwithstanding further treadle movement. The force of the springs 44 may be varied by turning the-adjusting screw 47 and the stroke of the treadle 50 shortened by means f the adjusting screw 81 j,

Further'depression of the treadle'50 will merely cause the piston housing 20 to rise untilthe treadle latch 64 engages the catch plate 56 by which time the last with theinsole attached will be gripped as required between the clamps 12 and 14 ready for the trimming and beveling operation to be performed.

If, while the last is'clamped in the machine, there is a loss of fluid which results in a loss of pressure, the tension springs 44 permit thepiston housing 20 to be lowere'd'about the fulcrum 30 but the pistons 88and 126 remain in their upward positions as set by the treadle 'action.. Thus the downward movement of the piston housing'. relative to.the high pressure piston 126 will cause an increaseof pressureabove the high pressure piston 126 equalto the amount lost by the fluid leakage so that the pressure on the clamp 14 will remain substantially constant notwithstanding the fluid loss. Should there be a leakageof fluid between the walls of the cylinder'124' and the highpr'essure piston 126, the lost fluid would be. guided into thespace above the low pressure piston 88 by means of a fiat 164 on the plunger-118 creating a slot along which the fluid may travel. This flat also affords a means for fluid to'pass up to the space above the sleeve 120' when the high pressure piston 126 rises thus avoiding-the creation of a vacuum below this piston which is undesirable. a i In practice there will be found a wide variation in the size of last which maybe gripped in the machine. Accordingly, for alarge last theclamp will. not be required to move as great a distance as for a small last and correspondingly the volume of fluid required to effect the desired pressure is not as great.

When a smaller quantity of fluid than previously used in the machine is needed, as for, example, when changing from a smaller to a larger'last, the clamp 14 may contact-the last before the low pressure piston 88 completes its movement into contact with the plunger 118 of the high pressure piston 126. This results in an increase of fluidpressure in the space above the piston cover 114. When this increased pressure exceeds the force of the spring 98, the plug 102 and the valve seat 110 descend, creating a space between the downwardly extending rim 112 of the piston cover'114 and the upper surface of the valve seat 110. Fluid escapes through this space into the recess 104 and from there by way of the passageway'162 enters the channel 152 until the pressure decreases and the valve seat 110 closes and again seals with the rim 112. This escape of fluid continues, if necessary, until the low pressure piston 88 has completed the upward movementready for the high pressure force to be exerted.

The last is released from the clamps 12 and 14 upon the discontinuance of the fluid pressure which is effected by the depression of a treadle plate 74 which, as de.

scribe above, disengages the latch 64 and permits the treadle 0 to rise under the action of the spring .78. With this movement the low pressure piston 88 is lowered and the highpressure piston 126 also moves downwardly aided by the force of the spring 138.

mounted will now be described; The jack extends for, wardly in a substantially horizontal position'and is piv oted at its rearward portion on a pair of coaxial pins 166 at opposite sides of the frame 4. The axis of the pins 166 is parallel to and below the axis of rotation of the cutting means. Also pivoted on the pins 166 is a pair of parallel links 168 which extend upwardly and rearwardly of the machine. The ends of the links 168 opposite the pins16'6 are pivoted on a shaft 170 journale'd in the toprearward portion of the frame 4. By this construction the jack may be moved forwardly and rearwardly by the swinging movements of the links 168 while the workis free to rotateinthejack. I 1 n Extending rearwardly from the O-shaped jack 10is an arm 172 on the rearward portion of which is a pin 174 anchoring a tensioning spring 176. The opposite end of the spring 176 is secured to the base 2 (Fig. 1). The spring 176 normally supports the jack in ahorizontal position. .7 I Theflexible pipe 16 is connected to an elbow 178 which is secured to the left-hand end of the clamp 'cylin: der 180 in which slides the spindle of the clamp 14. The right-hand end of the cylinder 180 is flanged as at' 181 (Fig. 5). A flange sleeve 182 abuts the flange 181 and extends into the cylinder 180. The left-hand end of the jack is forked and has a pair of arms 184 embracing the cylinder 180 and contacting its flange 181. A pairfof screws 186 are threaded through theflange of'th'e sleeve 182 andthe cylinder 180 and clamp the cylinder 180 to the arms 184 of the fork of the G-shaped jack. A plate 188 bridges the arms 184 being secured theretoby screws 190'to assist in holding the cylinder 180 in place." R'otat'i able on the flange 181 is. a collar 192 on which is formed a. lug 194 to which is secured a leaf spring 196 by: screws 198.. The spring 196 extends toward the clamp 12 and formed in the spring is a slot 200. (Fig- .4); ex? tending about one-halfits length. At the right-hand end' of the spring are two downwardly inclined ar'rns 201', extending respectively toward the front and rearof the machine. The purpose of this spring will become more apparent hereinafter. I

The construction of the clamp 14 will now be described. Freely movable within the bore of the cylinder'180 is a spindle 202, 'having a reduced portion or rod 204 atits left end which fits Within a piston 206 and is secured thereto by a nut 208 threaded on the red. .A return; spring 210 is compressed between the piston 206' and the end of the sleeve 182. The spring 210 surrounds the: spindle 202 and in turna portion of the piston 206 s ur? rounds'approximately one-half of the spring. A spindle sleeve 212 rotatably engages the righthand end of the spindle 202 and threaded into the sleeve 212 is a pin 214 which enters the slot 200 formed in the spring 196 whereby upon rotation of the spindle sleeve 212, turning movement is imparted to the spring.- At the right end of the spindle 202 is mounted a ball race 218 which engages the face of a clamp plate 220 secured to the right-hand, end of the spindle sleeve 212. Dovetailed in the right hand face of the clamp plate 220 is a last-engaging pad] 222 of resilient material which contacts the back cone" of a last. By-this construction the pad 222," the clamp plate 220, the spring 196 and the spindle sleeve 212 are? freely rotatable as a unit about the axis of the spindle 202. A key 224mounted on the sleeve 182 engages a keyway} 226 in the spindle 202 to prevent the spindle from rotating with the clamp 14. p At the right-hand end of the C-shaped jack- 10 is mounted the clamp 12whici1-will now be described.

A' bore 228 is formed in the right-handend of the jackcoaxial with the bore of the cylinder 180 and secured in the bore 228 by a screw 230 is a shaft 232. Sur rounding the shaft 232 is a ball race 234 engaging a clamp plate 236 in the face of which is dovetailed a padj 238 of resilient material which engages the heelen'd of the insole attached to the last. By this construction," the 7 pad 238 and the plate 236 are rotatable relative to the jack to permit the ,last to rotate while the cutter 1s operating .around the heel end of the insole.

The lastwith the insole attached is placed between the clamps 12 and 14, the upper heel end of the last being presented to the .clamp 14 and the heel portion of the insole being positioned toward the clamp 12, the end ,or counter portion of the last being centralized between the arms 201 of the spring 196. The clamp 14 is urged toward the clamp 12 by depressing the treadle whereupon the clamp 14 moves first under low pressure piston action .and then by high pressure piston action against the clamp 12 as above described. When the treadle has been latched, the pressure applied to the insole and last by the clamps will be constantly maintained by the compensating springs 44 so that the last with the insole attached is gripped ready for presentat'ion to the cutter without further effort on the part of the operator. This gripping pressure will remain constant :at all times and for all sizes of work.

.The cutting means 8 will now be described with reference to Fig. 5. A rotary toothed cutter 240 and a shield 242 are clamped to the left-hand end of the cutter shaft 6. interposed beween the teeth of the cutter 240 are additional hardened cutting elements 244 individually mounted on a carrier 246 rotatably mounted on the Shaft 6. A compression spring 248 urges the carrier 246 to the left, the spring being mounted between the carrier and a collar 250 secured to the shaft.

The cutter 240 is used for trimming the periphery of the insole and the cutting elements 244 are used to impart a bevel to the insole and also to disperse chips adhering to the insole. By. this construction, insoles of different thicknesses may he beveled in the machine without adjustment. In trimming and beveling a thick insole the cutting elements 244 are caused by the insole pressing against the shield 242 on one side and the cutting elements 244 on the other to move to the right against the action of the spring 248. The amount of displacernent of the beveling cutter 244 in a direction axially of the shaft 6 is dependent upon the thickness of the insole.

A last guide 254 is provided for engagement with the-last adjacent the heel seat face and serves also as acutter guard. The last guide comprises a left-hand face 256, sides 258 and a flange 260, as seen in Fig. 6, the peripheral edge of the flange 260 being substantially clover-leaf shaped as seen in Fig. 7. Since the last guide also serves as a cutter guard it will be appreciated that as the cutters are worn with use and regrinding they will diminish in' size. To accommodate the cutter as it diminishes in diameter the last guide 254 is formed with three cutter shrouding segments (a) large, (b) medium, (1;) small, in sections integral with each other thereby presenting an appearance similar to a clover leaf as seen in Fig. 7. These segments are formed as circles of different diameters. Formed in the last guide 254 are three holes .I-I so located as to permit the adjustment of the last guide to permit the most advantageous use of the segments a, b and C, as Will become more apparent hereinafter.

. Formed on the face 256 of the last guide at a position approximately equidistant from said three holes H is a projecting pin 262 rotatably mounted in a block 264 forming part .of a gage plate 266. Mounted in the block 264 adjacent the bore engaged by the pin 262 is a spring-biased plunger 268 which is engageable with any one of the holes H. The gage plate 266 extends rearwardly of the machine and is slidably mounted in a support 270 engageable with a lug 272 formed on the machine integral with a dust hood 274. A spindle 276 is mounted in coaxial bores of the lugs 272 and the sup port 270 so that the support 270, the gage plate 266, the block .264 and thelast guide 254 are pivotal as a unit about the spindle 276. To secure the support with the last in operative-position a wing nut 278 threaded on a bolt .280 engages a lug 282 depen ng rom "the support 270 seen in Fig. 7.

Threaded into a bore 284 formed in the end of the support 270 is an adjusting screw 286 having a knurled head 288 and surrounding the adjusting screw 286 'but rearwardly of the bore 284 is a collar 290. Sandwiched between the collar 290 and the head of the screw 286 is an end plate 292 the left-hand portion of which is secured to the rearward end of the gage plate 266 by a screw 294.

To adjust the last guide, the wing nut 278 is unscrewed and the last guide 254 is pivoted in a clockwise direction, as seen in Fig. 6, about the spindle 276. When the guide 254 has cleared the cutting means 8, the plunger 268 is withdrawn from whichever hole H its tip is then received by and the guide rotated about the pin 262, the pin 268 being permitted to enter either of the other holes H, depending upon whichever segment of the a, b, or c it is desired to utilize. The last guide is then pivoted into its operating position. Adjustment forwardly and rearwardly of the machine may be required and is effected by rotation of the screw 288 to move the plate 266 relative to the support 270 in which it is mounted.

To bevel the insole of a shoe in the illustrated machine a last with the insole attached is secured between the clamps 12 and 14 in the jack 10 as heretofore described. Since the clamp plates 22,0 and 236 are rotatable it follows that the last and insole are rotatable as well, the jack being pivotal about an axis parallel to and below the axis of rotation of the cutter. The last may be pivoted about this axis in an upward direction to present the insole to the cutter. Because the links 168 to which the jack is pivotally connected are pivoted about an axis parallel to and above the axis of rotation of the cutter, the last may be raised upwardly relatively to the cutter as well as outwardly thereof if desired.

When the last with insole attached is presented to the cutting means 8, the insole is placed between the shield 242 and the rotary cutter 240, the heel end of the last bearing on the sides 258 of the last guide 254. By virtue of the means hereinbefore described the movements of the last with insole attached are such that when the beveling operation is being performed the insole may be presented to the cutting means so that it may be beveled from its shank portion at one side thereof right round its heel portion to the opposite shank portion irrespective of the size of the last. Once the last with the insole attached has been gripped between the clamps all the operator has to do is guide the last, by gripping the forepart thereof, round the cutting means. The clamps 12 and 14 keep the last with the insole attached firmly in position and during the beveling operation the shield 242 assisted by the last guide 254 prevents the insole slipping from the cutting means 8.

When the beveling operation has been completed, the operator lowers the C'shaped jack 10 and presses the treadle plate 74. The low and high pressure pistons 88 and 126 are lowered, and the piston 206 urged by the return spring 210 moves leftwardly in the clamp cylinder causing the last with insole attached to be released from the grip of the clamping means.

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 machine for operating on a shoe part mounted on a last, a tool, a work supporting jack movable toward and away from said tool, means for clamping in said jack a last with part of a shoe attached thereto comprising a first clamp mounted in said jack, a cylinder on said jack, a piston slidable in said cylinder for movement in axial alinement with said first clamp, a second clamp mounted on said piston, a fluid pump for directing pressurized fluid to said cylinder to move said second clamp toward said first clamp, and tension means for rendering said fluid 91 pump operative 'for' compensating for variations in pressure in said fluid; after the shoe, partand last have been clamped in order to maintain a constant clampingforce between saidflrst and second clamps.

2. In a machine for operating on a shoe part mounted on a last, a tool, means for supporting part of a shoe and last for presentation to said tool comprising first and second clamps, fluid operated means for moving said second clamp toward said first clamp to grip the shoe part and last therebetween, means for supplying pressurized operating fluid to said clamp moving means comprising a cylinder communicating with said clamp moving means, a piston in said cylinder, means to movesaid piston in a direction to compress fluid within said cylinder, and means to move said cylinder relative to said piston to compensate for variations in pressure of the operating fluid after the shoe part and last have been clamped.

3. In a machine for operating on a shoe part mounted on a last, a tool, means for supporting part of a shoe and last for presentation to said tool comprising first and second rotatable clamps, fluid operated means for moving said second clamp toward said first clamp to grip therebetween the shoe part and last, means for supplying pressurized operating fluid to said clamp moving means comprising a cylinder communicating with said clamp moving means, a piston in said cylinder, means to move said piston in a direction to compress fluid within said cylinder, means to move said cylinder relative to said piston to compensate for variations in pressure of the operating fluid after the shoe part and last have been clamped, and means to adjust the force with which said cylinder moving means moves said cylinder relative to said piston.

4. In a machine for operating on a shoe part mounted on a last, a tool, means for supporting a shoe part and last for presentation to said tool comprising first and second clamps, fluid operated means for moving said second clamp toward said first clamp to grip therebetween the shoe part and last, means for supplying pressurized operating fluid to said moving means comprising a frame, an arm having one end pivoted on said frame, a cylinder pivoted on said arm between its ends and communicating with said clamp moving means, a piston in said cylinder, means to move said piston in a direction to compress fluid within said cylinder, said cylinder and said arm being movable in the same direction as said piston when fluid is compressed in the cylinder, and yieldable tension means connecting the opposite end of said arm to said frame to resist such movement of the arm and cylinder.

5. In a machine for operating on a shoe part on a last, a tool, means for supporting a shoe part and last for presentation to said tool comprising first and second clamps, fluid operated means for moving said second clamp toward said first clamp to grip therebetween the shoe part and last, means for supplying pressurized operating fluid to said moving means comprising a frame, an arm having one end pivoted on said frame, a cylinder pivoted on said'arm between its ends and communicating with said clamp moving means, a piston in said cylinder, means to move said piston in a direction to compress fluid within said cylinder, said cylinder and said arm being movable in the same direction as said piston when fluid is compressed in the cylinder, yieldable tension means connecting the opposite end of said arm to said frame to resist such movement of the arm and cylinder, and means to adjust the force of said yieldable tension means.

6. In a machine for operating on a shoe part mounted on a last, a tool, means for supporting a shoe part and last for presentation to said tool comprising first and second clamps, fluid operated means for moving said second clamp toward said first clamp to grip the shoe part and last therebetween, means for supplying pressurized operating fluid to said clamp moving means comprising a cylinder having one end in communication with 10 said clamp moving means, a first pistonslidable in said cylinder, means to movesaid first piston toward said one end of the cylinder to compress fluid therein, a second piston slidable in said cylinder of smaller diameter than said first piston, said second piston being normally spaced from said first piston in a direction toward said one end of the cylinder and movable relative to said first piston, a fluid passageway through said second piston, a valve on said first piston to seal said passageway when the first piston moves into engagement withthe second piston whereby when said first piston is initially moved in its fluid compressing direction pressurized operating fluid passes to the clamp moving means through the passageway in the second piston and after said passageway is sealed the operating fluid between the second piston and the clamp moving means is further compressed.

7. In a machine for operating on a shoe part mounted on a last a tool, means for supporting a shoe part and last for presentation to said tool comprising first and second clamps, fluid operated means for moving said second clamp toward said first clamp to grip the shoe part and last therebetween, means for supplying pressurized operating fluid to said clamp moving means comprising a cylinder having one end in communication with said clamp moving means, a first piston slidable in said cylinder, means to move said first piston toward said one end of the cylinder to compress fluid therein, a second piston slidable in said cylinder of smaller diameter than said first piston, said second piston being normally spaced from said first piston in a direction toward said one end of the cylinder and movable relative to said first piston, a fluid passageway through said second piston, a valve on said first piston to seal said passageway when the first piston moves into engagement with the second piston whereby when said first piston is initially moved in its fluid compression direction pressurized operating fluid passes to the clamp moving means through the passageway in the second piston and after said passageway is sealed the operating fluid between the second piston and the clamp moving means is further compressed, and means to move said cylinder relative to said first and second piston to compensate for variations in pressure of said operating fluid after the shoe part and last have been clamped.

8. In a machine for operating on a shoe part mounted on a last, a tool, a work supporting jack movable toward and away from said tool, means for clamping in said jack a last with part of a shoe attached thereto comprising a first clamp mounted in said jack, a cylinder on said jack, a piston slidable in said cylinder for movement in axial alinement with said first clamp, a second clamp mounted on said piston, means for directing pressurized fluid to said cylinder to move said second clamp toward said first clamp comprising a member movable by the operator through a predetermined stroke, and means modifying the action of said last named member whereby a predetermined pressure is applied to the work by said clamps regardless of variations in the size of the work.

9. In a machine for operating on a shoe part mounted on a last, a tool, a work supporting jack movable toward and away from said tool, means for clamping in said jack a last with part of a shoe attached thereto comprising a first clamp mounted in said jack, a cylinder on said jack, a piston slidable in said cylinder for movement in axial alinement with said first clamp, a second clamp mounted on said piston, a member movable to direct pressurized fluid to said cylinder to move the second clamp toward the first clamp, and means modifying the action of said member in its movement to cause a predetermined pressure to be applied to and maintained on the work by said clamps.

10. In a machine for operating on a shoe part mounted on a last, a tool, a work supporting jack movable toward and away from said tool, means for clamping in said jack a last with part of a shoe attached thereto comprising a first clamp mounted in said jack, a'cylinder on said jack, a piston slidable in said cylinder for movement in axial alinement with said first clamp, 21' second clamp mounted on said piston, 21 member movable to a predetermined position to direct pressurized fluid to said cylinder to move the second clamp toward the first clamp, and means modifying the action of said member in its movement to said predetermined position to cause a predetermined pressure to be applied to and maintained on the work by said clamps.

- References Cited in the file of this patent UNITED STATES PATENTS Dorman May 31,

Thresh Feb. 13,

Snyder Dec. 22,

Stratton July 23,

FOREIGN PATENTS Great Britain Nov. 27,

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