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Title:
Drilling machine
United States Patent 2379944
Abstract:
This invention relates to machines by which various drilling operations may be performed, it being especially applicable to the simultaneous production of a plurality of bores in shoe-heels. In Letters Patent of the United States No. 2,200,385, Eich, May 14, 1940, is disclosed a method of...


Inventors:
Willmott, Herbert J.
Application Number:
US49741543A
Publication Date:
07/10/1945
Filing Date:
08/04/1943
Assignee:
UNITED SHOE MACHINERY CORP
Primary Class:
Other Classes:
144/93.2, 144/278.1, 184/6.14, 184/6.26, 184/11.1, 408/48, 408/61, 464/179
International Classes:
B27C3/04
View Patent Images:
Description:

This invention relates to machines by which various drilling operations may be performed, it being especially applicable to the simultaneous production of a plurality of bores in shoe-heels.

In Letters Patent of the United States No. 2,200,385, Eich, May 14, 1940, is disclosed a method of attaching heels to shoes. This method consists in inserting a group of nails in the heel-seat of a shoe in accordance with a chosen design, with portions of said nails projecting outwardly from the heel-seat-surface, forming in a heel at the cup passages coinciding in design and location with those of the nails in the heel-seat, and forcing the thus formed heel upon said nails.

An object of my invention is to provide for drilling passages of this character in groups, the design of which may be varied readily and accurately, both in the relation of the passages to each other and that of the group to the work. It is also desired to effect the drilling operation rapidly and with the necessity for little thought or effort upon the part of the operator. With this in view, the machine of the present invention consists more essentially of a mechanism by which a heel or other work-piece is located and held for the operation upon it, and a mounting by which a plurality of chucks or drill-holders may simultaneously be positioned in accordance with a particular design, there being relative reciprocation between the work-holding means and the mounting to produce the action of the drills.

As particular features of the invention, improvements have been made in the mechanism by which heels of varying sizes are correctly positioned with reference to the drilling mechanism and clamped for the drilling operation; in the means for preventing injury by the drills to improperly located elements of the machine; and in the means for disposing of the waste produced in drilling.

There were filed in the United States Patent Office on December 21, 1944, three divisional applications having the Serial'Numbers 569,121, 569,122 and 569,123. These are directed, respectively, to the drilling mechanism, to the guiding means for the drill-chucks, and to the auxiliary hydraulic pressure mechanism.

One of the many possible embodiments of the invention is illustrated in the accompanying drawings, in which Fig. 1 shows my improved drilling machine in front elevation; Fig. 2 is a side elevation thereof; Fig. 3, a top plan view; Fig. 4, an enlarged vertical sectional detail of the waste-removing means taken on the line IV-IV of Fig. 1; Pig. 5, a perspective view of the heel-supporting breast-bar; Pig. 6, an enlarged front elevation of the heelclamping mechanism; Fig. 7, a vertical longitudinal section on the line VII-VII of Fig. 1, and including the heelholder and a portion of its actuating mechanism; Fig. 8, an enlarged sectional detail of the indexing means for the vertical adjustment of the heel-clamping mechanism, taken on the line VIII-VIII of Fig. 1; Fig. 9, a broken sectional detail through the shock-absorbing mechanism associated with the treadle; Fig. 10, a broken front elevation of the guideplate for the drills; Fig. 11, an enlarged front elevation of the drilling mechanism, with the means for varying the drilling design; Fig. 12, a vertical section through the drillholders on the line XII-XII of Fig. 11; Fig. 13, a sectional detail on the line XII-XIII of Pig. 11; Fig. 14, an enlarged longitudinal sectional detail through one of the drill-chucks; Fig. 15, a similar view of the connection between the chuck and its flexible driving shaft; Fig. 16, a broken longitudinal section through said shaft; Fig. 17, an enlarged transverse section on the line XVII-XVII of Fig. 16; Pig. 18, an enlarged broken longitudinal section on the line XVIII-XVII of Fig. 2, illustrating the yieldable reciprocating connection for the drill-slide; Fig. 19, an enlarged elevation of the drill-driving mechanism, looking from the left in Fig. 2; Fig. 20, a vertical section on the line XX-XX of Pig. 19; Fig. 21, an irregular vertical transverse section taken at the left of Fig. 20, particularly showing the gearing through which the drills are driven; Fig. 22, an enlarged central vertical longitudinal section through the cam and clutch mechanism; Fig. 23, a transverse section on line XIIIXXII of Fig. 22; Fig. 24, a top plan view of the cover for the casing of the cam and clutch mechanism; Pig. 25, a vertical sectional detail of the auxiliary pressure mechanism, taken on the line XXV--XXV of Fig. 2; Fig. 26, an enlarged horizontal sectional detail through the operator-actuated portion of the drill-setting mechanism on the line XXVI-XXVI of Fig. 1; Fig. 27, an enlarged side elevation of the latching mechanism for the clutch-tripping link; Fig. 28, a top plan view of the elements appearing in Fig. 27; Fig. 29, a transverse section on the line XXIXXXIX of Fig.*30, showing the means for guiding and clamping the drilling head; Fig. 30, a top plan view of the means for -setting and clamping the drilling head; Fig. 31, a front elevation of the actuating means for the heel-centering and clamping mechanism, taken back of the auxiliary pressure mechanism of Fig. 25; Fig. 32, a vertical sectional detail on the line XXXII-XXXII of Fig. 30; Fig. 33, an enlarged top plan view of the outer end of the adjusting means for the depth of drilling, taken at the left of Fig. 32; Fig. 34, a horizontal sectional detail through the locking means for the depth-adjusting scale; Fig. 35, an enlarged sectional detail of the locking means for one of the drill-holders, taken on the line XXXV-XXXV of Fig. 11; Fig. 36, a front elevation of said locking means; Fig. 37, an enlarged sectional detail on the line XXXVI-XXXVII of Fg. 11; Fig. 38, an enlarged horizontal sectional detail on the line XXXVIII-XXXVI of Fig. 1, particularly showing the waste-removing passages and conduits; and Fig. 39, a horizontal section through one of the chip-removing nozzles.

As best appears in Fig. 2 of the drawings, the machine comprises more essentially chuck mechanism A, by which a plurality of drills for operating upon heels may be held in individual chucks K and adjusted to different positions to give arrangements corresponding to a particular design in which nails have been inserted in the heelseat of a shoe to which the drilled heel is to be attached; driving mechanism B by which the drills are rotated through flexible and extensible connections X permitting drill - adjustment; clutch, cam and fan mechanism C interposed between the motor or other source of power and the drill-driving mechanism; and clamping mechanism D with its actuating connections by which the heels are held for the drilling operation.

These mechanisms will be considered separately.

Chuck mechanism A (Figs. 2, 3, 8, 11-18, 26, 29, 30 and 32-37) Upon spaced rods 50, 50, fixed horizontally from front to rear in the upper portion of the frame 52 of the machine (Fig. 2), a main drillactuating slide 54 is movable, and has supported upon it a mounting head 56 for drill-chucks K, here shown as five in number (Figs. 11 and 12).

To the slide is imparted a reciprocation of unvarying extent to cause drills 58, held in the chucks, to operate upon the work. That the slide may move smoothly upon both the rods 50, without cramping, one of said rods passes through spaces 55 in the slide with substantial clearance.

In each of these spaces the vertical play is taken up by a gib 57 on which the slide bears and which is adjustable by screws 59 threaded through the slide and bearing against the gib.

A cam 60, rotatable by the mechanism C once during each operating cycle of the machine, by contact with a roll 61 rotatable on a bell-cranklever 62 fulcrumed at 64 upon the mechanism C, oscillates said lever. A roll 66 upon the lever 62 engages the closed end of a, thimble 68, movable through a bore in a lug 10 depending from the slide 54 (Fig. 18). A spring 72 is seated in the thimble 68 with its opposite extremity in an externally threaded thImble 74, adjustable through an opening in the frame. By turning a nut 75 upon the thimble 14, there may be varied the force with which the spring urges a flange 16 upon the thimble 68 against the lug 10, and holds the slide 54 in its normal position with the drills retracted. This position is determined by the contour of the cam 60, in engagement with which the roll 61 Is maintained by the spring. Between a lug 78 depending from the slide and a sleeve 80 sliding in the frame, a spring 82 is interposed. This last-mentioned spring Is of such strength that it will resist the force necessary to advance the drill-slide 64 for the production of the deepest openings to be formed in the work.

It is under constant compression, its force being adjustable by rotation of a screw 84 threaded into the sleeve and against which the outer end of the spring abuts. The expansive force of this spring 82 maintains the lug 78 of the slide in contact with a horizontal crossbar 86, bridged between a pair of links 88, 88 pivoted to the upper end of the lever 62. At their rear extremities, these links are joined at 90, 90 to the sleeve 80. The crossbar, the links and the sleeve move at all times with the lever and may be considered to be a portion thereof. They furnish a carrier for the spring 82. As the cam 60 oscillates the lever 62, its action upon the thimble 68 compresses the spring 72. This movement of the lever-portion 86 permits the spring 82, by its engagement with the lug 78, to move the slide 54 forward, so the drills 58 act upon the work. If any obstruction is encountered by the drills or slide which offers a resistance greater than the maximum drilling force, it merely causes the compression of the spring 82, and no injury to the elements of the machine will result. When the lever 62 is allowed by the cam 60 to be swung back by the expansion of the spring 72, the slide 54 is retracted by the contact of the flange 16 with the lug 10 at a rate determined by the contour of the cam. This, and withdrawal of the drills from the work, will be rapid, so heating by idle rotation of said drills within the work is minimized. The time of withdrawal may be a relatively small fraction of that required for the operating advance. Since the lug 78 and the screw 84, which furnish the abutments for the opposite ends of the spring 82 move together with the lever 62, the resistance to compression of said spring is unaffected by the depth of drilling: The action of the drills is therefore more uniform, and both the springs 72 and 82 may be of less strength than if the screw 84 were a normally fixed abutment. Since the operating force is applied to the drills through the spring 82 and they are retracted by the spring 72, their movement in both directions is cushioned and all shocks absorbed to give smooth reciprocation of the main slide 64.

To provide for drilling heels to different depths, the position of the mounting head 56 upon the main slide 54 is variable. For this purpose, the mounting is fast upon an intermediate or secondary slide 92 movable in ways 94 upon the main slide. The connection of the mounting to the slide 92 may be by screws 95, which pass with some clearance through openings in the connected elements. Thus is furnished a transverse setting-up adjustment for the drills 58. At the underside of the secondary slide is a lug 96, in which turns a rod 98 (Figs. 1, 2, 30 and 32) having collars 100, 100 fixed to it at opposite sides of the lug, and threaded into the,main slide at 102, this thread being right hand. When the rod is turned by a hand- wheel 104 upon its forward extremity, the secondary slide and the mounting 56 with the drills are adjusted to different initial distances from the work, so that unvaried travel of the main slide will carry the' drills into the work to a greater or less extent. In its adjusted position, the secondary slide is locked by engagement of a block 106, movable upon the main slide 54 through one side of the ways 94 and forced against the secondary slide (Figs. 29 and 30). This movement of the block is effected by a toggle-lever, one link 108 of which is pivoted to it at 110, the other link 112 being pivoted to the first and also to the main slide at 114. The pivot 114 is furnished by an eccentric, which may be rotated to different positions, and is secured by a screw 116. This permits the normal angle between the links of the toggle, and, therefore, the extent of locking movement of the block 106 to be varied. The center of the toggle is forced against an adjustable stop-screw 118 into locking relation by an expansion-spring 120 surrounding a rod 122 pivoted to an arm 124 extending from the toggle-link 108. The spring is interposed between a bracket 126 projecting from the main slide and a shoulder 128 upon the rod. To unlock the slide 92 for adjustment, the rod 122 is drawn out by a handle 130 (Figs. 1 and 2), breaking the toggle and withdrawing the block 106 from its locking position, to which it has been urged by the spring 120. With the secondary slide thus freed, the mounting head 56 and the drills may be moved to the desired positions by rotation of the handwheel 104. Unless the rod 122 is drawn out while the adjustment is being made, the secondary slide is held locked ready for the drilling operation.

To guide the operator in making the adjustment of the drills, there projects from the main slide 54 through an opening in the frame about the rod 98, a tube 132 (Figs. 2, 7, 32 and 33) terminating adjacent to the hand-wheel 104.

The tube is cut away along its upper side, and its edge is graduated at 134 in fractions of an inch. Guided in the tube along the graduated opening is an elongated nut 136 engaging the rod 98 by a left-hand thread. A projection 138 from the nut into a longitudinal groove 140 in the tube prevents the rotation of said nut. As the rod 98 is turned to produce the adjustment of the slide 92 and the drill-mounting 56 on the main slide, the forward extremity of the nut travels along the scale, indicating the depth of drilling for any setting. The opposite threading of the rod into the nut and the slide multiplies the indicating travel of the former, so the scale may have longer gradations and be more easily read. To allow an adjustment of the zero position of this gaging device, the tube 132 is clamped in the main slide 54, with a capacity for longitudinal adjustment, by a wedge 142 (Fig. 34).

The wedge is guided in said main slide and bears against the tube. It is forced into locking engagement with said tube by a screw 144 threaded into the wedge and rotatable in the slide 54 (Fig. 30).

In a depression 150 in the rear face of the upper portion of the mounting 56 is secured a holder 152 for one of the drill-chucks K (Figs. 11, 12 and 13), this corresponding to the rear nail.

Four other holders 154 are guided in radiating or outwardly diverging depressions 156, and at the inner extremity of each of the holders 152 and 154 is a horizontal bore 158 to receive a chuckshaft 160. Each of the holders 154 has near its outer extremity a rearward projection: 162, entering a cam-slot 164 in a circular plate 166 rotatable in a recess at the rear of the mounting and retained in place by a cover 168. The plate has an upwardly extending arm or hand-hold 170, through which it may be turned by the operator.

A latch 172 upon the arm enters any one of a series of notches 174 in a segment 176 attached to the top of the mounting 56, to fix the plate in any one of a plurality of angular positions corresponding to different drilling and inserting designs, indicated by designations 178 associated with the segment-notches. To permit the notched segment to be brought into correct relation to the holders, as positioned by the camslots, it is secured to the mounting by slot- and screw-connections 179. To guide the holders accurately in their movement of adjustment, each 23 has at one side a longitudinal V-groove 180 (Figs. 36 and 37). Lying in this groove is an elongated guide member 182 having side walls, complemental to and contacting with those of the. groove. This guide member is movable upon the mounting and retained in place by a cover-plate 184 and screws 186 which extend with some clearance through openings in said plate. Threaded in the mounting and passing loosely through an opening in the cover-plate is a generally cylindrical clamping member 188, which has an inclined peripheral surface 190 engaging a complemental surface 192 upon the guide member (Fig. 37).

The clamping member is provided with a slotted head 194, through which it may be rotated to urge the surface 190 against the surface 192, thereby forcing the inclined surfaces of the guide member into engagement with the opposed surfaces of the groove 180. There it is secured by tightening the screws 186. Thus, there are furnished by the member 182 two extended surfaces by which the holder is compelled to move along the correct path during its adjustment. This insures the entrance of the drills into openings in an abutment-plate of the clamping mechanism D and their precise arrangement in the chosen drilling designs. The clamping member may be secured by a locking plate 196 having an opening, the conical wall 198 of which contacts with the complementally inclined periphery of the head 194. The locking plate is attached to the coverplate and forced into its locking relation by a screw 200, threaded into the cover-plate with its head bearing against the locking plate. Each chuck-shaft 160 is rotatable in flanged bushings 202 (Fig. 12), fitting the opposite ends of its holder-bore 158, and has threaded upon its forward extremity a flanged sleeve 204 (Fig. 14).

This forces back into a conical depression in the shaft a collet 206, which clamps in place one of the drills 58. At the rear, each chuck-shaft is threaded at 208 to receive its driving connection (Fig. 15). This arrangement minimizes the space necessary to receive the closely spaced chucks K.

Driving mechanism B (Figs. 2, 12, 15-17 and 19-21) 'The driving mechanism B has a casing 216 (Fig. 20), the opposite ends of which are closed 75 at the rear by a head 218, and at the front by a head 220. In ball-bearings 222 and 224, in the casing and rear head, respectively, is journaled a. horizontal central shaft 226 extending through a passage 228 and rotated at a high speed by beltgearing 230 from a motor 232 mounted near the bottom of the frame 52 (Fig. 2). Fast upon the forward extremity of the shaft, in a space 233 between the body of the casing and the forward head 220, is a pinion 234, with which mesh pinions 236, one secured to each.of five shafts 238 arranged symmetrically about and parallel to the central shaft. Each shaft 238 turns in ball-bearings 240 and 242, respectively mounted near the forward, and rear ends of passages 244 through the casing. The bearings are held in position longitudinally of the shaft and wear taken up, by springs 246 abutting against the raceways of the bearings 242 and acting through interposed sleeves 248 surrounding the shafts 238 to force the raceways of the bearings 240 against segmental plate-sections 250 (Fig. 21) secured to an inner wall of the casing 216. The forward end of each shaft 238 has an enlargement 252 extending into an opening 254 in the casing-head 220.

In this enlargement is a threaded axial bore, in which is received the threaded end of a connecting sleeve 256, which is soldered to a short length of flexible shaft 258 (Fig. 16) furnishing a portion of a compound shaft X by which rotation is transmitted from each of the driving shafts 238 to the chuck-shafts 160. The opposite end of each shaft 258 is similarly joined to the outer section 260 of a telescopic shaft. The co-operating inner section 262 of this shaft has secured to its outer extremity a length of flexible shaft 264, which is joined by a soldered and threaded connecting sleeve 266 to the end 208 of the chuckshaft. The two telescoping sections are compelled to turn together by opposite pairs of interengaging ribs and grooves 268 (Fig. 17), this arrangement balancing the weight and preventing vibration from being set up in the high-speed mechanism. Since the shafts X are both extensible and, in part, flexible, there are made possible the bodily movements of the chuck-mounting 56 with and upon its actuating slide 54, to permit the operating movement of the drills and their adjustment upon the mounting, for different depths of drilling and for different drilling designs. The character of the flexible shafting permits, without interference, the close spacing of the chucks K for small drilling designs. Further, such a connection requires no lubrication, as does a universal joint.

To furnish lubrication for the bearings of the high-speed shafts of mechanism B, there is utilized a splash-system combined with the circulation of oil-vapor. Journaled in the lower portion of the casing 216 is a horizontal shaft 270 (Figs. 20 and 21), upon which is secured a gear 272 meshing with one of the pinions 236. As the gear is rotated by this engagement, its teeth dip in a body of oil O contained in a chamber 274, formed at the bottom of the casing-space 233. The height of the oil may be observed through a window 276 at the end of the casing. The upwardly moving teeth of the rapidly rotating gear 272 travel close to a partition 278 projecting inwardly from the side wall of the casing. The oil carried up by the teeth past the edge of the partition is, therefore, limited, and a considerable portion is deflected back into the chamber by a curved surface 280 at the underside of the partition. The oil thrown by the teeth above the partition strikes a curved wall 282, the larger drops falling back to be again struck by the teeth, while the smaller pass up to contact with the teeth of the pinions 234, 236 Sand with one another, to form a vapor which is *forced rearwardly through the casing to lubricate the bearings 222, 224, 240 and 242. The provision of these oil-deflecting surfaces and contracted openings prevent the delivery of an excessive quantity of oil to the gearing, if the oil-level in the chamber 274 is high. Drops of oil -thrown from the pinions 236, together with oil-vapor, which tends to escape through the openings 254, strike frustoconical surfaces 284 upon the enlargements 252 of the shafts 238, and are deflected back into the casing to be vaporized.

In the casing 216, rotatable by the shafts thereip, are devices by which the vapor is circulated through the bearings. Upon a portion of maximum diameter of each shaft-enlargement 252 adjacent to the head-opening 254 is a vertical face, in which are grooves 282 to produce centrifugally currents of air, which aid in the production of the oil-vapor and have the effect of forcing it into the corresponding passages 244. They also draw air into the passages through the openings 254 in the casing-head 220, thus serving to cool the bearings through which it is carried with the oil-yapor. Further, this intake assists in preventing oil from escaping through the openings. Rotatable with each shaft 238 upon the sleeve 248 is a fan 290, the inclination of the blades of which is such as to produce suction drawing the vapor through the passages, and, therefore, through the bearings 240 and into the bearings 242. Spaces 292 (Fig. 21) between the plate-sections 250, and grooves 294 (Fig. 19) in the forward wall of the casing 216 and joining the adjacent passages 244, allow free travel of the oilvapor between and to the rear of the bearings 240. Reaching the bearings 242, a portion of the vapor passes through them, while the excess is diverted through grooves 295 in the casing to the opposite side of the bearings. To prevent the oil from working out through the openings 254 in the casing-head 220, in addition to the effect of the grooves 282, a helical g1oove 296 is formed about each shaft-enlargement 252 within the openings. The direction of the helix is such as to convey the oil entering the opening back into the casing. The tendency of the oil to creep out through the circumferential space about the enlargement is further decreased by the presence of a depression 298, at the bottom of the space and closed at its outer end. In this depression, the oil gathers and flows back to the interior of the casing.

The central shaft 226 carries a fan 300, the blades of which produce an air-current drawing the oil-vapor from the space 233 into the passage 228, it entering through the bearing 222 and passing on through the bearing 224. Grooves 301 in the casing and a space 303 in the head 218 at the bearings 222 and 224, respectively, dispose of the excess of the vapor. To guard against the flow of the vapor out of the casing through the opening 302 between the shaft 226 and the rear head 218, there is fixed to the shaft, just inside the opening, a disk 304 in which are grooves 306, these grooves generating an optward current of air which forces the vapor away from the opening. Vapor which has passed through the bearings 242 and 224, together with portions which have condensed at the rear of the bearings to liquid form, descends through the space 303 and a space 308 in the rear head and casing, respec16 tively, and are returned to the chamber 274 to be again circulated. The courses followed by the vapor and liquid are indicated by series of arrows in Fig. 20. To avoid the building up of such pressure in the chamber 274 that the circulation of oil may be checked by back-pressure, said chamber is vented through a passage 310 (Fig. 19). That there may not be any substantial escape of oil-vapor through this passage to the outer air, it discharges through a condenser Y.

A container 312 is connected to the passage, and in it is a body 314 of some such substance as steel wool held between screens 316, 316. The oil-vapor entering this material gathers upon it as a liquid to flow back through the passage 310 into the chamber. Any uncondensed vapor which passes through the condenser Y is disposed of through a pipe 318, as will later appear.

Clutch, cam and fan mechanism C (Figs. 2, 3, 22, 23 and 24 20 Rotatable in bearings 330, 330 at the top of a casing 334, carried at the central rear portion of the frame 52 upon cross-rods 336, is a horizontal shaft 338, driven through the belt-gearing 230.

In a secondary casing 340 attached to one side of the casing 334, the shaft carries a fan 342, which produces a blast of air through a conduit 344 leading to a plurality of outlet-openings, later to be described, at the clamping mechanism D and adjacent to the field of action of the drills 58. By this air-current the chips and dust resulting from the drilling are removed from the work and adjacent elements of the apparatus, and disposed of through a suction-conduit 346, which may be connected to the factory-exhaust-system. The oil-vapor exhaust-pipe 318 leads into the conduit 346 at 348 (Fig. 3), so the waste-vapor is disposed of with the chips. The discharge-opening of the exhaust-pipe is sufficiently contracted, to prevent the suction in the conduit 346 from drawing the vapor from the casing-space 233. A worm 350 fast upon the shaft 338 meshes with a wormwheel 352 upon a horizontal shaft 354, journaled in bearings 356, 356 in the lower portion of the casing 334. The worm-wheel may be connected to the shaft 354, to cause its rotation or to be freed therefrom, by single-rotation clutch mechanism M controlled by connections, as hereinafter explained, to a treadle-lever 362 fulcrumed upon a spindle 363 extending transversely across 30 the bottom and rear of the frame 52. The previously mentioned cam 60 for causing the reciprocation of the slide 54 with the drill-mounting 56 is fixed to. the shaft 354, together with a cam 364 by which the heel-clamping mechanism D is :5 controlled. To lubricate the various bearings carried by the casing 334, oil is contained in a chamber 366 at the bottom of the casing, and into this the worm-wheel 352 dips. Oil is thrown by the worm into the clutch and against the cover-plate (;;C 368 of the casing. On this cover-plate are downwardly inclined ribs 370 (Fig. 24), conducting the oil to projections 372 from which it drips into passages 374 leading to the bearings 330 and 356.

Heel-clamping mechanism D and its connections, G;5 including the control of the clutch M (Figs. 1-10, 25-29, 31 and 38) At the front of the frame 52 is an upward extension 380, and guided at the opposite edges of the extension is a carrier-slide 382 (Figs. 6, 7 and 38). The upper central portion of the slide is cut away at 384. and at the lower edge of this opening is attached to the slide a breast-bar 386 (Figs. 4 and 5), having a downwardly and outwardly inclined surface 388 furnishing a support or rest for the breast-edges of the heels to be drilled.

The periphery of the heel-cup rests against an abutment-plate 390, separably secured to the frame-extension. In the plate are openings in which are guided the drills 58 to prevent their lateral displacement. These openings include one at 392 (Fig. 10), through which passes the rear drill of the inserting design which occupies an unvarying position for all heels, two downwardly and outwardly inclined openings 394 in which the succeeding pair of drills may move as the design changes, and then two downwardly and outwardly inclined series of openings 396 to receive the drills for different adjustments. Guided horizontally, at each side and just above the bar 386, is a horizontally movable contact member 398 (Fig. 6), the twb members being for the purpose of centralizing the heel upon the bar, so a line bisecting it from the center of the breast to the center of the rear will come in the same position for heels of all sizes. Such a line will register with a like line through the center of the guideplate-opening 392. Each member 398 is engaged by an upwardly extending arm of a bell-cranklever 400, fulcrumed by angularly adjustable eccentrics 402 upon the slide 382. This mounting of the levers allows the members 398 to be brought to their proper normal relation in which the heel is correctly located. A horizontally extending arm of the bell-crank is rounded at its inner extremity and lies within an opening 404 in a secondary slide 406, guided for vertical movement in ways in the slide 382. At its lower extremity, the secondary slide is joined by a connecting rod 408 to an arm 410, arranged to turn about a transverse shaft 412 rotatable at the front of the lower portion of the frame 52 (Figs. 1, 2, 7 and 31).

This arm is joined by a relatively light torsionspring 414 to the hub-portion of an upwardly extending actuating arm 416 attached to the shaft.

The arm 416 is operated to apply simultaneously the centralizing force to the opposite members 398 through the spring 414 to urge the heel to its true position. The spring has relatively little strength, because practically no displacing force is exerted by the work against the members 398. At one side of the rear of the slide 382, an upwardly and forwardly curved arm 418 is pivoted, this carrying at its forward extremity a padded fork 420 adapted to contact with the rear of the heel which has been applied to the bar-surface 388.

Fast with the arm 418 is a second arm 422 connected by a link 424 to an arm 425, free to turn about the shaft 412 and joined by a torsionspring 426 to the arm 416. Upon movement of the arm 416, the spring 426 transmits its force to the arm 418 and its fork to force the lastnamed element against the rear of the positioned heel. The spring 426 is relatively heavy, since it must actively resist displacement of the arm 418 by the action of the drills upon the heel.

The breasts of all heels to be operated upon engage the bar 386 in the same relation upon the carrier-slide 382, but, as the heels vary in size and the inserting design changes, the drillopening 392 for the rear nail will be at different distances from the breast. To properly locate clamped heels of all sizes to receive the drilling, the carrier-slide with the entire clamping mechanism is raised or lowered upon the frame-extension 380, it moving transversely of the plate 390. Then, to maintain a substantially constant relation of the shaft 412 and the arms which it carries to the clamping elements which they actuate, the bearings 428, in which the shaft turns, are carried by a slide 430 movable vertically in ways 432, 432 in the frame (Figs. 7 and 31).

Means is provided for adjusting these slides 382 and 430 simultaneously in the same direction.

For this purpose, there depends from the slide 382 a link 434 guided at one side by a roll 436, rotatable upon the frame, the link having at the opposite side rack-teeth 438 meshing with a pinion 440 fast upon a short shaft 442 rotatable in the frame (Figs. 1 and 26). Upon this shaft is a second pinion 444, meshing with rack-teeth 446 on a link 448 rising from the slide 430 (Fig. 31).

A roll 450, rotatable on the frame opposite the pinion 444, guides the link 448. Also secured upon the shaft 442 is a hand-wheel 452 and a disk 454, the latter having in its periphery depressions 456 which may bear designations 457 Sin fractions of an inch. One or another of these depressions may be engaged by a spring-actuated detent 458 (Figs. 7 and 8) guided upon the front of the frame. This detent is raised by the operator to free the disk or released to lock said disk in its adjusted position. The depressions are to be so spaced that movement of the disk from engagement of the detent with one depression to the next will raise or lower in the same direction and to the same extent the slides 382 and 430. This will be sufficient to give predetermined locations of the heel-clamping means for drilling all sizes of heels.

To produce the centralizing and clamping of the heel upon the breast-bar 386 by actuation of the links 408 and 424, respectively, and to trip the clutch M to cause the operating movement of the drills 58, there is journaled transversely of the frame 52 above the shaft 412 a shaft 440, upon which are secured five arms (Figs. 2 and 31).

An arm 462 is joined to the arm 416 by a roll 464 rotatable upon it and projecting into a slot 466 in said arm 416. A second arm 468 on the shaft 460 is articulated at its lower extremity to one link 470 of a toggle-lever. The other link 472 of this lever is fulcrumed at 474, and has a rearward extension 476 connected by a tensionspring 478 to the treadle-lever 362. A link 419 joins this treadle to the center of the toggle-lever, a slot 480 in the link receiving the pivot-pin 481 of the lever. The spring 478 serves the double purpose of maintaining the treadle normally raised and the toggle 470, 472 broken, to an extent determined by an adjustable stop-screw 477 which is engaged by a lug upon the link-extension 476. A third arm 482 fast upon the shaft 460 has an arcuate surface 484, upon which a latching lever 486 may ride, urged counterclockwise by a torsion-spring 487 surrounding its fulcrum at 64. The arm 482 also has a shoulder 488 behind which the downwardly projecting end 489 of the latching lever may fall to lock the shaft 460 with its arms in the.position to which they may be moved by the treadle to clamp the work. To allow the shoulder to be brought to the proper relation to an element co-operating with it, said shoulder is shown as formed upon a separate arm-section 483, arranged to turn about the shaft 460 and secured to the arm 482 by a slot-andscrew connection 485. A fourth arm 490 (Fig. 27) upon the shaft is united through a link 492 to the tripping mechanism of the clutch M.

When the operator depresses the treadle, the first action is to swing the actuating arm 416 counterclockwise (Fig. 2) as a result of the engagement of the upper end of the slot 480 with the pin 481. This applies force through the torsion-springs 414 and 426 and the transmitting or secondary actuating arms 410 and 425, respectively, to centralize by the members 398 a heel which has been placed upon the breast-bar 386 and to clamp it by the fork 420. Then, the arm 482 is moved into a position in which it is latched by the end 489 of the lever 486 engaging the shoulder 488, and, finally, the clutch is tripped by the arm 490 and link 492 to start an operating power-cycle of the machine. This causes the drills to advance, make their openings in the work, and retreat to their initial positions.

At the close of the operation, the cam 364 of the mechanism C actuates the lever 486 to unlatch the arm 482. This is in preparation for the breaking of the toggle 470, 472 by the spring 478, with the restoration of the heel-engaging elements to their normal positions and the elevation of the treadle.

It is to be noted that, when the adjustment of the height of the slide 382 is made to correctly locate the heel-clamping means for the drilling of different sizes of heels, the slot 466 in the arm 416 will travel along the roll 464 upon the arm 462. This varies the effective length of the arm 416 upon which the toggle-lever acts when the treadle 362 is depressed. The smaller the heel the shorter the length of the arm, and the more rapidly the fork 420 will be carried into clamping engagement with the heel. This compensates for the difference in diameter of the heels, and causes the time of such engagement to be substantially uniform for all diameters and in the same relation to the time the clutch M is tripped. All heels are, therefore, fully clamped before the drills go into action.

When a rapidly releasing clutch is employed, it may under certain conditions be possible for the operator, by a second depression of the treadle, to initiate prematurely a second cycle. To prevent this, an auxiliary latch is applied directly to the clutch-controlling link 492. This latch 500 is pivoted at 502 upon the frame 52 with its hooked engaging end 504 above an arcuate surface 506 upon an upward projection 507 from the link 492 (Figs. 27 and 28). The latch is urged toward the projection by a torsion-spring 508, but is held up initially by contact with a depending latchtail 610 of a screw 512 threaded through an upward projection 514 from an extension of the arm 490. A horizontal projection 516 from the arm 490 lies within an arcuate slot 518 in the link 492. The link is under the influence of a spring 520 included in the clutch mechanism M (Fig. 22), to hold the clutch normally open.

As illustrated, the elements are in their normal or resting positions. When the operator depresses the treadle 362, the shaft 460 and the arm 490 are turned clockwise (Fig. 2), and the toggle-lever 470, 472 is straightened. The contactscrew 512 moves away from the latch-tail 514, so the latch is released. The hooked end 504 is carried by its spring against the arm-surface 506, where it is ready to descend and latch the link 492 in the clutch-tripping position. When the projection 516 reaches the right-hand end of the slot 518, after the clamping.arm 418 for the heel has been operated, it shifts the link to the right and allows the latch-end 504 to drop behind the link-projection 507. The link transmits the movement of the treadle to clutch mechanism M to trip it, and the latch positively retains the link against return for repetition of its clutch-tripping movement. Upon release of the treadle after the completion of an operating cycle, and the togglelever 470, 472 Is broken by the spring 478, the projection 516 moves idly to the left in the slot 518. The contact-screw 512 approaches the latch-tail 514, but does not engage this until just at the termination of movement of the arm 490.

This engagement lifts the latch and releases the link, so it may beĆ½ returned by the spring 520 to the position from which it may again be shifted to trip the clutch. This ensures that a full operation will have been completed, with a restoration of the treadle to its highest or normal position, before the operator can again cause the operation of the machine. The latching lever 486 makes certain the continued clamping of the work by the arm 418 through a complete operating cycle, regardless of the position of the treadle.

When the treadle is released by the operator and the toggle 470, 472 broken by the spring 478, the force with which the lug on the extension 476 strikes the stop-screw 477 might be considerable, were not means provided to absorb the shock.

For this purpose, as is best shown in Fig. 9, the link 479 has at its upper extremity a piston 522 movable in a cylinder 524 suspended from a supporting arm 526 clamped in place upon the framerods 336 (Fig. 2). The piston, with its cupped washer 528, fits tightly in the cylinder, resisting the elevation of the link 479 by the spring 478, while air is escaping from the cylinder above the piston through a contracted opening 530, Movement of the piston in the opposite direction during the depression of the treadle is facilitated by the relief of suction past the washer and through passages 532 extending longitudinally of the piston-wall.

Since the displacing force exerted upon the clamped heel by the advancing drills 58 is comparatively great, the operator might be called upon to apply to the treadle 362 a force to heavy to be exerted readily. I have, therefore, utilized the final movement of the treadle acting through hydraulic mechanism W to increase the pressure upon the work and give a final clamping effect.

Referring to Figs. 1, 2 and 25, the generally horizontal arm 425 upon the shaft 412 is extended at 540 and divided to receive between its separated arms a cylinder 542. Entering this cylinder from above is a tubular member 544, which acts as a guide for the associated reciprocating elements and furnishes a head for the cylinder. The member 544 is supported upon the frame by a bracket 546, upon which it is pivoted. At its under side the member 544 has a cupped washer 548 for the retention below it in the cylinder of a body of oil or other fluid, and through its reduced stem 549 into the cylinder are opposite openings 550, 550.

Beside the treadle 362, turning about the spindle 363, is a transmitting arm 552. Rising from this arm is a yoke 554 having depending from its upper cross-arm 556 a rod 558, which fits within the tubular stem 549 of the member 544 and furnishes the active piston of the mechanism. This has a cross-sectional area substantially less than that of the cylinder 542. The arm 552 is held up normally by a tension-spring 564 to a point determined by a stop-screw 566, threaded vertically through it and contacting with a portion of the frame. At U.is time, the lower end of the rod 558 is just above the stem-openings 550 (Fig. 25). Pivoted to the arm 552 is a link 568, at the upper end of which is a vertical slot 570. This receives a lateral projection 572 from an arm 574 fast upon the shaft 460 with the arms 462, 468, 482 and 490. With a heel in place on the breast-bar 386, the operator depresses the treadle, moving the centering members 398 and the clamping member 418 into engagement with the heel.

When this occurs, the torsion-springs 414 and 426 yield, permitting the continued motion of the treadle though the rods 408 and 424, which actuate the heel-engaging members, have stopped.

As the toggle-lever 470, 472 is being straightened by the continuing depression of the treadle, the shaft 460 is turned clockwise (Fig. 2), lowering the arm 574 and shifting the projection 572 idly along the slot 570 in the link 568. Just before the movement of the arm 492 causes the tripping of the clutch M to produce the action of the drills upon the heel, the projection reaches the lower extremity of the slot. This depresses the link 568, and, therefore, the arm 552, yoke 554 and piston 558. This at once closes the openings 550 and, until the completion of the treadle-depression, the piston acts to compress the oil in the lower portion of the cylinder. Because of the ratio of the areas of the rod and cylinder, the force exerted is greatly multiplied, and this io transmitted through the cylinder and the link 424 to the arm 418 to apply an adequate clamping force to the heel with relatively little effort on the part of the operator.

Safety mechanisms (Figs. 1, 2, 3, 6, 10 and 13) To permit the heel being operated upon to be 30 positioned for all the drilling designs, the breastbar 386 must be raised for the smaller designs until it is opposite the lower pairs of drill-guiding openings 396 in the plate 390, through which the drills are projected. Such a relation is shown in Fig. 1. Were the bar thus located and the design changed by a forgetful operator from a smaller to a larger arrangement without a corresponding adjustment of the slide 382, the drills in their operation would penetrate the bar. To guard against this, the slide and the design-adjusting lever 170 are interconnected, so the former cannot be brought to such a height that the drills can injure the breast-bar. Pivoted at 580 at the top of the frame is an arm 582, having turning with it at the pivoted end a depending portion 584, which has a stepped lower extremity 586 curved inwardly and upwardly, so the steps lie successively at greater heights from left to right.

From the slide 382 is a projection 588, the outer upper contact-corner 589 of which lies below the steps 586. Extending longitudinally of the arm 582 is a cam-slot 590, which a projection 592 from the rear of the arm 170 enters (Fig. 13). The contour of the slot 590 is such that, for each setting of the arm 170 for a particular drilling design as determined by the graduations 178, there will be vertically alined with the contactcorner 589 upon the slide the horizontal surface of a particular one of the steps 586. This will prevent the elevation of said slide by the handwheel 452 to a point which would cause the breast-bar to be brought into the path of the drills. Conversely, if the slide is first positioned and an attempt is made to adjust the arm 170 improperly, the vertical surface of one of the steps will strike the contact-corner 589 and prevent adjusting the drills to too large a design.

When the treadle 362 is depressed to effect the locating and clamping of a heel and the operation of the drills, the centering members 398 are, in absence of means to limit this movement, carried yieldably in through the torsion-spring 414 until they are stopped by engagement with the sides of the heel. If there is no heel in place upon the breast-bar, or if a small heel is thus positioned, the centering members may move over openings 396 in the plate 390, and, If the design is such that the drills pass through these openings, the members will be injured. Such a condition, I prevent by limiting the inward movement of the centering members under the control of the slide 382. In the stationary guideplate 380, near one side, is a depression 594 (Fig. 6), at the outer edge of which is a cam-surface 59.6. This is shown as at the left of the plate. The lever 400 of the corresponding member 398 has a downwardly extending arm 598, upon which is a roll 600 lying in the depression. The camsurface from a to b is so formed with respect to the inserting designs, that for any adjustment of the slide 382 the roll 600 will rest against a point upon the cam-surface, which will so stop outward movement of the arm 598, its lever 400 and the opposite lever connected by the actuating slide 406, that the two members 398 will be held clear of the drills. The position of the slide 582 is controlled by the contact-surfaces 586, to prevent it from being set for a heel smaller than that for which the drills are adjusted.

Disposal of the waste (Figs. 1-5, 38 and 39) In connection with the mechanism C, reference has been made to the fan 342, from which a blast of air is delivered through the conduit 344 to remove from the clamping mechanism the chips 30 produced by the action of the drills 58 upon the work, such chips being disposed of through the suction-conduit 346. Each of the conduits 344 and 346 is provided with a vertical terminal portion 606, having a sliding connection with depending conduits 608 from a horizontally elongated head 610, which is attached to the front of the slide 382. This connection of the conduits provides for the vertical movement of the slide 382. From the blast-conduit 344 the air passes-40 to a chamber 612 in 'he head 610 (Fig. 4), and then through opei i- s 614, 614 in the slide (Fig. 38) to a chamber 616 in the slide at the rear of and below the oreast-bar 386. From the chamber 616, the ah is discharged at a high velocity through a set of vertical openings 618 in the breast-bar just in front of the plate 390. This effectively forces away from the surface 388 the waste which falls from the drills at the cup-surface of the heel being operated upon. Secured at the top of the head 610 at each side of the breast-bar is a nozzle 620, these being respectively in front of the heel-centering members 398.

Each nozzle receives the air-blast through an opening' 622 in the top of the head, and delivers it through three openings 624, 626 and 628 (Fig. 39)! Each opening 624 is at the apex of the inclined rear face of the nozzle and is vertically elongated, it removing the waste from the breastbar between the members 398 outside the breastedge of the cup of the drilled heel. The opening 626 lies horizontally across the upper portion of the inclined face of the nozzle and blows the chips from the tops of the members 398. The opening 628 is in the inner nozzle-face, directing the blast across the center of the breast-bar. The cemnbined air-currents, with the chips, travel outwardly above a passage 630 formed at the bottom of a depression 632 at the center of the head 610 and which terminates in the suction-conduit 346. Through this conduit all the waste is removed to a collecting point. Chips, falling from the drills at the inner side of the plate 390, will be received by a chamber 640 formed in the frame and will enter openings 642 at the bottom of the chamber. As appears in Fig. 1, these openings are connected to the suction-conduit.

Operation When a size or type of heel is to be drilled, differing from that for which the machine previously has been adjusted, the operator must know the inserting design in which nails have been set in the heel-seats of shoes to which the new run of heels are to be attached; the distance by which the rear nail is to be spaced from the breast-edge of each heel; and the depth of drilling, to provide for the proper reception of the nails by the drilled openings. For these three arrangements, there are respectively made the following adjustments. The hand-hold 170 Is moved as determined by a design-designation 118 to shift the holders 154 of the drills 58 upon the mounting head 56 of the chuck mechanism A.

The hand-wheel 452 is rotated through an angle indicated by one of the designations 457 to raise or lower the slide 382 of the clamping mechanism D, and, therefore, the breast-bar 386, the heelcentralizing members 398 and the arm 418 which it carries with respect to the drill-guiding openings in the abutment-plate 390. In this movement, the actuating elements upon the slide 430 travel with the heel-engaging elements upon the slide 382, to maintain the two groups in an unvarying relation to each other. The hand-wheel 104 is turned to alter the location of the secondary slide 92, with the drills 58, upon the main slide 54 toward or from the clamping mechanism D, in accordance with one of the graduations 134.

The slide 92 is secured by the block 106 and spring 120 and released for setting through the rod 122.

In these adjustments, the interaction between the hand-lever 170 and the slide 382 at 586, 589 and the control of the centralizing members 398 by the cam 596 on the slide 382 prevent injury to the breast-bar 386 and the members 398, through negligence of the operator during changes from smaller to larger drilling designs. All the adjustments may be made with the drills in rotation.

With the heel-engaging elements thus correctly related, the operator places a heel H (Fig. 6) with its breast-edge upon the breast-bar and the periphery of the cup against the plate 390, and depresses the treadle-lever 362. This straightens the toggle-lever 470, 472, thereby turning the shafts 412 and 460. Through the torsion-spring 414, the members 398 are carried in yieldably to locate the heel symmetrically with respect to the openings in the plate 390, through which the drills 58 are to pass. Then, through the torsion-spring 426, the arm 418 is swung down to bring its fork 420 against the rear of the heel and apply thereto preliminary clamping pressure. After this centering and clamping of the heel have been effected, continued lowering of the treadle further rotates the shafts 412 and 460. The, springs 414 and 426 yield, while the shaft 460 turns the arm 574.

The connected arm 552 energizes the auxiliary mechanism W, its small piston 558 acting through stem 549 upon the liquid in the large cylinder 542 to apply increased final clamping pressure through the rod 424 and arm 418 to the heel. This is sufficient to resist the maximum displacing force which the drills may exert upon the heel, without burdening the operator. After the heel is thus positioned and finally clamped, depression of the treadle continuing, movement of the arm 490 by the shaft 460 shifts the link 492 to trip the clutch M of the mechanism C.

Following this action, the link is latched at 100, so it cannot again be moved until an operating cycle has been completed and the treadle fully raised. As the cam 364 of the mechanism C starts in rotation, it releases the latch-arm 486 for engagement with the arm 482 upon the shaft 460.

This retains the heel clamped, regardless of pressure exerted by the operator upon the treadle, which is customarily released immediately upon depression. The cam 60 is also driven by the mechanism C and, acting upon the lever 62, causes the main slide 54 of mechanism A to advance the drills 58, yieldable against the constant resistance of the spring 82, into the heel to the chosen depth, to be retracted by the spring 12.

The drills are in constant rapid rotation through the driving mechanism B, which is thoroughly lubricated by oil vaporized by the action of the toothed gearing 212, 234, 236 and effectively circulated and cooled. The reciprocation and adjustment of the drills with reference to the stationary driving mechanism is permitted by the extensible and flexible shafts X. At the close of the power-cycle of the machine, when the cams 60 and 364 have returned to their initial positions, the latter will release the latching lever 486 and, therefore, the arm 482 on the shaft 460.

The toggle-lever 470, 472 is broken by the spring 478, while the arm 652 and auxiliary pressure mechanism W are returned to normal by the spring 564. Just as all the elements arrive at their initial positions, the latch 500 for the clutchtripping link 492 is disengaged, then, and then only, rendering the machine ready for the succeeding operation. The heel-centralizing members 398 and the clamping arm 418 will have left the drilled heel, which will fall or be removed by the operator from the breast-bar 386. During the drilling operation, the waste produced is completely removed from the work and its engaging members by the air-blast delivered through the conduit 344 and the openings in the breast-bar and in the nozzles 620, and drawn off through the passage 630 in the head 610, the openings 642 in the frame and the suction-conduit 346.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is: 1. In a drilling machine, a work support including adjustable gage means adjustable along a predetermined path for positioning different sizes of work for drilling, a drill support, means for guiding and reciprocating one of said supports toward and from the other in a drilling operation, adjustable drill holder means on said drill support adjustable to different predetermined positions for drilling of said different sizes of work, said adjustable gage means or a drill in said drill holder, upon being adjusted from one size of work to another being capable of passing across the previous location of the other, and means to determine that the other is adjusted to its new location prior to a further drilling operation to prevent a drill contacting the gage means, including stop means connected for automatic operation in accordance with the movement of one of said adjustable means and projectable by said operation into the path of a part connected to and movable with the other said adjustable means to stop an adjustment of either said means relative to the other in which the gage means would cross the drill path of a drill in said holder means.

2. In a drilling machine, a work support including adjustable gage means adjustable along a predetermined path for positioning different sizes of work for drilling, a drill support, means for guiding and reciprocating one of said supports toward and from the other in a drilling operation, adjustable drill holder means on said drill support adjustable to different predetermined positions for drilling of said different sizes of work, said adjustable gage means or a drill in said drill holder, upon being adjusted from one size of work to another being capable of passing across the previous location of the other, and means to determine that the other is adjusted to its new location prior to a further drilling operation to prevent a drill contacting the gage means, including stop means connected to and movable with one of said adjustable means and selectively projectable thereby into the path of a part connected to and movable with the other said adjustable means to different limiting positions, corresponding to said adjustment positions of said adjustable means, to stop an adjustment of either said adjustable means relative to the other in which the gage means would cross the drill path of a drill in said holder means.

3. In a drilling machine, a work support including adjustable gage means adjustable along a predetermined path for positioning different sizes of work for drilling, a drill support, means for guiding and reciprocating one of said supports toward and from the other in a drilling operation, adjustable drill holder means on said drill support adjustable to different predetermined positions for drilling of said different sizes of work, said adjustable gage means or a drill in said drill holder, upon being adjusted from one size of work to another being capable of passing across the previous location of the other, and means to determine that the other is adjusted to its new location prior to a further drilling operation to prevent a drill contacting the gage means, including a stop member having spaced stops disposed along the path of adjustment of a part connected to and movable with one of said adjustable means, and means connecting said stop member for automatic operation in accordance with the movement of the other said adjustable means for selectively projecting said stops into the path of said part to stop an adjustment of either said adjustable means relative to the other in which the gage means would cross the drill path of a drill in said holder means.

4. In a drilling machine, a work support, a drill support, means for guiding and reciprocating one of said supports toward and from the other to effect a drilling of the work, a drill holder movably mounted on said drill support for adjustment to predetermined different drilling locations, each location presenting a different drilling path in accordance with a different size of work, work positioning means movable at an angle to said drilling paths, means for moving the positioning means from an inoperative position to a position to engage the work on said work support to position it for drilling, said last named means being capable of moving the positioning means a short distance to engage a large size of work or longer distances to engage smaller sizes of work, said positioning means in its movement from engagement with a large to a smaller size of work passing the drilling path of a drill in said holder corresponding to an adjustment of said holder to a large size of work, and means corresponding to said different drilling paths for stopping the work engaging movement of said positioning means so that it will not intersect a drilling path, due to either the drill not being adjusted to its new location or a smaller piece of work being inserted than the drill is adjusted for, said means for stopping the work-engaging movement including stop means for limiting the work'engaging stroke of said positioning means and means for adjusting said stop means in accordance with the movement of said adjustable drill holder and for automatically maintaining said stop means adjusted for a work engaging stroke of said positioning means short of the drill path to which said drill holder is adjusted.

5. In a drilling machine, a work support, a drill support, means for guiding and reciprocating one of said supports toward and from the other to effect a drilling of the work, a drill holder movably mounted on said drill support for adjustment to predetermined different drilling positions, each position presenting a different drilling path in accordance with different sizes of work, work positioning means movable at an angle to said drilling path, means for moving the positioning means from an inoperative position to a position to engage the work on said work support and position it for drilling, said last named means being capable of moving the positioning means a short distance for a large size of work or a maximum distance for a small size of work, and therefore capable of extendink said positioning means across a predetermined drilling path in the absence of work on said support of a size at least as large as that for which said drill holder is adjusted, stop means for preventing such extended movement of said positioning means that would intersect a drilling path, said stop means including two stop members, one of which is connected to and movable with said positioning means and engageable with the other stop member to limit the work engaging stroke of said positioning means, and means for adjustably changing the limit position of one of said members with respect to the other and with respect to the changed drilling path and for automatically maintaining said limit position adjusted for a work engaging stroke of said positioning means short of the drill path to which said drill holder is adjusted, whereby to prevent the positioning means being contacted by a drill in case the machine is operated without work on said support or on work which is smaller than the size for which the drill holder is adjusted.

6; In a drilling machine, a work support, a drill support, means for guiding and reciprocating one of said supports toward and from the other to effect a drilling of the work, a drill holder movably mounted on said drill support for adjustment to predetermined different positions, each position corresponding to a different drilling path in accordance with different sizes of work, work positioning means movable at an angle to said drilling path, means for moving the positioning means from an inoperative position to a position to engage the work on said support and position it for drilling, said last named means being capable of moving the positioning means increasing distances for smaller pieces of work and thereby capable of extending said positioning means across a predetermined drilling path in the absence of work on said work support of a size at least as large as that for which said drill holder is adjusted, a mounting enabling adjustment of said work support and positioning means to different positions corresponding to said predetermined different positions of said drill holder, a cam on said mounting,'and a stop connected to and moyable with said positioning means and engageable with different portions of said cam at each of said different positions of adjustment of said positioning means to selectively stop the work engaging stroke of the positioning means at a point between its intended work adjusting position and the drill path for each said corresponding position of the drill holder, whereby to prevent the positioning means being contacted by a drill in case the machine is operated without work on said support or on work which is smaller than 'the size for which the drill holder and positioning means are adjusted.

7. A work holder comprising an apertured abutment through which a drill may be projected from one side of the abutment for a drilling operation on the other side thereof, a heel support at said other side of said abutment comprising a breast bar-adjacent the abutment on which a heel may be rested on its breast edge with the rim of the heel cup bearing against the abutment, centering fingers at opposite sides of said support, meahs for yieldably urging said fingers together to engage the sides of a heel on said breast bar and center it on the bar with respect to said abutment aperture, a clamping member engageable with the rear surface of a centered heel on said support intermediate the length of the heel, and operating means for said clamp arranged to force the clamp against the heel in a direction to produce a component of force toward the abutment and another component of force toward the breast bar, whereby to simultaneously clamp the rim of the heel cup against said abutment and the breast edge of the heel against the breast bar.

8. In a heel drilling machine, a drill holder carrying a plurality of drill chucks adjustable to different predetermined group positions for drilling different sizes of heels, a work holder aligned with the drill holder, means for reciprocating one of said holders toward and from the other for drilling a heel in said work holder, said work holder comprising an abutment having a plurality of sets of apertures for receiving and guiding drills contained in said chucks, each set of apertures corresponding to a different group position of said chucks, work holding means movably mounted at 60 the side of said abutment opposite said drill holder for positioning and clamping a heel against said abutment, and means movably mounting said work holding means for adjustment along the abutment to different positions, corresponding to said different group positions of adjustment of said drill chucks whereby a given size heel may be properly related to the corresponding group position of said drills and thus aligned with the corresponding set of apertures.

9. In a heel drilling machine, a drill holder carrying a plurality of drill chucks adjustable to different predetermined group positions for drilling different sizes of heels, a work holder aligned with the drill holder, means for reciprocating one of said holders toward and from the other for drilling a heel in said work holder, said work holder comprising an abutment having a plurality of sets of apertures for receiving and guiding drills contained in said chucks, each set of apertures corresponding to a different group position of said drill chucks, a rest for the breast edge of a heel at the side of said abutment opposite said drill holder, centering fingers movable from opposite sides of the rest to engage opposite sides of a heel on said rest and center it thereon with respect to said abutment apertures, means for operating said centering fingers to uniformly center heels of different sizes, a clamping member movable to engage a heel centered on said rest and clamp its breast edge against said rest and its cup against said abutment, and means for adjustably sliding said rest, centering fingers and clamping member uniformly along said abutment in a direction normal to the heel supporting surface of said rest to different positions, corresponding to said different group positions of adjustment of said drill chucks whereby a given size heel may be properly related to the corresponding group position of said drills and thus aligned with the corresponding set of apertures. .15 10. A work support including a rest for the heel and an apertured abutment, at the rearward edge of said rest, against which abutment the cup rim of a heel is clamped providing an area confined by the heel cup, cup rim and the abutment, the area opening between the abutment and the breast edge of the heel and the abutment aperture admitting a drill through the abutment, the confined area and to the heel cup in a drilling operation, means operative during and after a drilling operation to blast air from opposite sides of said rest across the surface of the rest and against the abutment and to blast air into said area through the aforesaid opening to prevent drill refuse from settling on said rest and abutment, a suction duct having an inlet adjacent said work support, and means for maintaining suction in said duct to withdraw air containing suspended drill refuse from about said support.

11. A work support including a rest for the heel and an apertured abutment, at the rearward edge of said rest, against which abutment the cup rim of a heel is clamped, the abutment aperture admitting a drill through the abutment to a heel in a drilling operation, centering members movable over opposite sides of the rest to engage a heel on the rest and position it for drilling, the clamped heel providing an area confined by the heel cup, cup rim and the abutment, the area opening between the abutment and the breast edge of the heel, means operative during and after a drilling operation to blast air over said rest and members to prevent drill refuse from settling thereon, said means including air blast nozzles at opposite sides of said rest arranged to direct air blasts inwardly along the surface of the rest and rearwardly across the surface of the rest and said members and against the abutment, and means for directing an air-blast through the aforesaid opening into the aforesaid area, a suction duct having an inlet adjacent said work.support, and means for maintaining suction in said duct to withdraw air containing suspended drill refuse from about said support.

12. A work holder including an apertured abutment against which the cup rim of a heel is clamped and through which aperture a drill is passed to the heel in a drilling operation, a rest for the breast edge of the heel, said clamped heel providing an area confined by the heel cup, cup rim and the abutment, the area opening between the abutment and the breast edge of the heel, and means operative during a drilling operation to blast air between the abutment and the breast edge of a heel and into said area toward the drill path to prevent drill refuse from settling on the rest and abutment.

HERBERT J. WILLMOTT.