US2274114A

US2274114A - Machine for operating upon hides, skins, leather, and other sheet material

Info

Publication number: US2274114A
Application number: US355502A
Authority: US
Inventors: Erastus E Winkley
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1940-09-05
Filing date: 1940-09-05
Publication date: 1942-02-24
Anticipated expiration: 1959-02-24

Description

Feb. 24, 1942. E. E. WINKLEY 2,274,114

' MACHINE FOR OPERATING UPON HIDES, SKINS,

LEATHER, AND OTHER SHEET MATERIAL Filed Sept. 5, 1940 v 3 Sheets-Sheet 1 Feb. 24, 1942. w Y 2,274,114

MACHINE FOR OPERATING UPON HIDES, SKINS,

LEATHER, AND OTHER SHEET MATERIAL Filed Sept. 5, 1940 3 Sheets-Sheet 2 E. E. WINKLEY 2,274,114

MACHINE FOR OPERATING UPON HIDES SKINS,

LEATHER, AND OTHER SHEET MATERIAL Filed Sept. 5, 1940 5 Sheets-Sheet 3 Feb. 24, 1942.

""IIIIIIIIIIJJ'III.VII

Patented Feb. 24, 1942 s PAT MACHINE FO RW OPERATING UPON HIDES, SKINS, LEATHER, AND OTHER SHEET MATERIAL Erastus E. Winkley, Lynn, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. .1., a corporation of New Jersey f Application September 5, 1940, Serial No. 355,502

50 Claims. (01449-471 This invention relates tomachines for operating upon hides, skins, leather, and other sheet material. While the invention isillustrated as embodied in a machine for operating a glazing tool back and forth over a tanned hideor skin, it isto be understood that the invention and various important features thereof may have other applications and uses.

i In commercial glazingmachines', as heretofore constructed, the glazing tool has been carried back and forth over a work piece by a lever mov-'- ing as a pendulum while the work piece rests upon a flat surface. In such an arrangement the stroke of the lever has been/constantly through the same length of arc irrespective of the dimensions of thework piece. Also,'in certain types of leather brushing, rolling, stoning, and whitening machines, the tool is moved back and forth a fixed distance irrespective of' the linear dimensions of thework pieces; "Hence, much of the operative stroke of these different tools is wasted where the work piece -is so idimen- -sioned and positioned that the travelof the tool thereon is short, while in other cases the entire stroke of the tool'produces its efiect on the work piece. From the very nature of theswinging movement of the tool; in the pendulum type of machines, it moves'at a faster rate incertain parts ofthe arc than in other parts. Thislack of uniformity in the rate of travel of. the tool over the surface of the work piece is not con-'- ductive to uniform results. Furthermore, in glazing machines of prior constructions no very satisfactory provision has been made to secure in. glazing operations a pressure suited to variations in the thickness work piece. e n

It is an object of this invention so to control a .35 dimensions of the means for shifting the work piece between the strokes of an oscillating or reciprocating tool.

Accordingly,:it is an important feature of the invention that the stroke of a'work treating tool is controlled with reference to a linear dimension of the work piece in the direction of travel of the toolso that the tool may promptly return for a succeeding work treatingstroke. An advantage of this construction resides in the fact that throughout the operative strokes of the tool useful work is performed, whereas heretofore the tool has been carried through a certain definite path although it might be, treating a work piece only through a part of such path. For controlling the tool, a detector means-is provided which moves in advance of the tool and controls the tool operating means to determine the length of the operative stroke of the tool and to reverse the tool promptly when it reachesthe edge oflthe work piece.

Another feature of importance in this invention relates to the provision of a sensitive means for varying the pressure of ,the Work treating operation in accordance with variations in the thickness dimension of the work piece in the path of a tool. Conveniently, a feeler member contacting the work piece in advance of the-tool exercises control of av mechanism for causing relative approaching and separating movements between the tool and a work supporting member. In the illustrated construction, the Work support is movable to press the work piece againstthe tool and is arranged to be retracted away from the tool when thinner and morecompressible portions of the work piece are presented for treatment, while thicker and denser portions of the work piece receive heavier pressure during the work treating operation.

work treating tool that the length of'its operative stroke will vary according to the dimensions-of the work, piece alongathevarious paths of the tool over the surface of the workpiece. It is a further object 'of the. invention; to provide a sensitive adjustment of the pressure of a work treating tool with respect to various thicknesses of 1 the work piece undergoing treatment." Still another object of the invention is to provide an improved machine in which the tool will travel at auniform rate during the operative stroke thereof, thereby contributing toxuniformity in the eifiects obtained. Whereas, in'most machines nowinv use 'inthe tanneries, the work piece has to'be manipulated by the operator to secure treatment} of successive portions therein, it 'is an object of this invention to provide-special -Another important feature of the invention resides in the provision of means for shifting a Work piecebetween operations of a work treating tool, a preferred construction being that in which the work shifting means also .places .a portion of the work piece under tension wherein it is held during a given work treating operation operations upon various parts of the work piece.

These and other important features of the invention and novel combinations of parts will now be described in detail in the specification and then pointed out more particularly in the appended claims.

In the drawings,

Fig. 1 is a view in side elevation and partly in section of a glazing machine illustrating one embodiment of the invention;

Fig. 2 is a front view of the machine shown in Fig. 1;

Fig. 3 is a plan View looking down from above on the machine shown in Figs. 1 and 2; and

Fig. 4 is a detail view of a valve mechanism utilized in the control of the hydraulic pistons of the machine.

In the illustrated machine, which is specially designed to perform glazing operations upon tanned hides andskins, there isprovided a table 6 for supporting a work piece while it. is being treated by a, glazing tool 8 (Fig. 1). The tool 8 is a glass roll of the type well known. in commercial glazing machines. As shown, it is firmly clamped against rotation, by av clamping member I0, fixed to the forward end of ahead or carrier H which is-slidable in the frame I2 of the machine ondove-tailed guideways best. shown at I4 in Fig. 2.

For controlling the length of the operative stroke of the tool 8, the illustrated machine is provided with novel detector means comprising, in the construction shown, a feeler member H3 at the forward end of a lever I 8- pivoted at 2!! on the head or carrier II. As shown, the feeler I6 is a forked member, the forward ends of which are substantially in alinementwith a plane passing vertically through the axis of the tool 8. At its rear end the lever I 6 is provided with a roll 22 which rides along the upper surface of a controller member 24 yieldingly supported by a spring 25 and carried by the upper end of a rod 26 slidable vertically in suitable bearings 2'I'i'n the frame of the machine) When the feeler or detector member I6 drops off an edge of the work piece during movement of the tool 8 and of the head II' to the right in Fig. 1, means (hereinafter described) is operated to terminate the operative stroke of ,the tool as soon as it reaches an edge of the work piece and to return the tool idly for a succeeding stroke across the surface of the work piece.

For operating the tool 8 at a uniform rate in its operative stroke, I have provided hydraulic means comprising a rack member 36' arranged to be reciprocated by piston heads 3!, 33 at opposite ends of the member 36. While, for cheapness of construction, the heads or pistons 3|, 33 are shown as made separate from the member 36, they may be made integral therewith. In any case, the member 30 with the

heads

31, 33 may be regarded as a piston member or device having a rack portion 32 to operate the tool 8. As shown, the rack 32 is arranged to be constantly in mesh with a segmental rack 34 secured to a shaft 361 rotatable in bearings in a stationary oil-tight casing member 38 secured to the frame 'of the machine- Secured to the end of the shaft 36 outside of the casing is a lever 46 which at its upper end is pivotally connected at 42 to a link 44 which is pivotally connected at its forward end to. the head or carrier II]. by the pivot pin 20. When the rack member 30. is reciprocated back and forth in its casing 50, the lever 46 is rocked to cause corresponding reciprocatory movement of the head or carrier I I and hence of the glazing tool 8. During the operative stroke of the tool 8 to the right in Fig. 1 it operates on a work piece on the table 6 while, during the return stroke of the tool to the left, the table 6 is depressed, by means hereinafter described, to prevent engagement of the tool with the work during its return stroke, the table 6 being moved upwardly into its elevated or operative position just prior to the beginning of the next operative stroke of the tool. For reciprocating the rack member 38,. hydraulic medium under pressure is admitted alternately to

piston cylinder heads

52, 54 through pipes 56, 58, respectively, opening through ports in the

cylinders

52 and 54, respectively. The other ends of the pipes 56 and 58 open into a chamber of a valve mechanism 66 which receives pressure medium, such as oil under pressure, from a pump 62 through a pipe 64 which opens into the valve chamber 60 through a port located at'a middle part of the length-of the valve chamber, the pump being driven by anywell-known power means such as a motor 6 I.

As shown most clearly in Fig. 4 of the drawings, the valve chamber has slidably mounted therein a hollow valve member 66 having a middle portion of reduced diameter so that liquid medium entering through the pipe 54 may pass in either direction to the ends of the chamber and. out alternately through either of the pipes 56 and 58, depending upon the position of the movable valve member 66. When the valve member 66 ismoved to the left in Figs. 1 and 4, the pressure medium flows through pipe 56 to the cylinder 52 and causes movement ofthe rack member to the right during which the liquid flows from thehead 54 through. the pipe 58. to the valve casing of valve 66 andinto the hollow movable valve member 66 and thence out through apipe' 68' to a sump 16. Upon movement of valve member 66 to the right, the liquid flows from pipe 64 to pipe 58 and moves the member 36in the reverse direction i. e., to the left, during which the pressure liquid escapes from cylinder 52 through the pipe 56. .to the sump pipe 68. It is to be noted that the valve member 66 when inits central position (Fig. 4) covers the openings of the pipes 56 and. 58 and that the least movement of the member 66 to the right permits liquid to pass from pipe 64 to and through pipe 58, while an equally small movement of 'the valve member 66 to the left directs liquid under pressure from pipe 64 to the pipe 56. The result is a sensitivity of valve action that produces instantaneous action in the hydraulically operated members.

hen a piece of work on the table 6. is up intofirm contact with the glazing 531 through the elevation of said table, the feeler or detector member I6 is lifted by the. work piece with the result that the rear end of the lever I8 is depressed, thereby effecting downward movement of the controller member 24 and of the rod 26 secured to its lower surface. Downward movement of the rod 26 has the effect of rockmg a bell crank lever M (Fig. l) in a clockwise direction. Since the upper end of the lever 14 is connected to a valve rod or stem 76 by means of acollar l8 slidable on the rod 76 against the tension of a spring 86' it follows tl v iat downw movement of the rod 26* is accompanied by moi ment of the rod 76' and of the connected valve member 66 to the rig-ht in- Fig. 1, with the result member 66 fully to the right in Fig, 1, and that thicker work parts will simply compress the spring 80 further, without oscillating the valve member 66. To limit movement of the valve to the right, and to prevent overthrow of member 66 there is provided a stop member -8I adjustable toward the adjacent end of the piston rod I6. On the other hand, when the feeler I6 drops off an edge of thework piece, the controller member 24 rises under the action of the spring 25 with the result that the bell crank I4, piston rod or stem I6 and valve member 66 move to the left (Fig. 1) whereby the hydraulic medium under pressure passes through the pipe 56 to the cylinder head 52 to effect instantly movement of the rack member or piston 30 to the right thereby causing the return or idle stroke of the glazing tool 8. Is should be noted in this connection that spring 80 (Fig. 1) holds the slidable collar I8 against a stop collar 82 pinned to the valve stem 16. During this return stroke of the tool, the work support 6 is lowered with the result that the tool does not operate on the work piece. Furthermore, the tool 8 remains at the left end of its stroke while the machine is in rest position, as shown in Fig. 1.

Hydraulic means is also provided for operating the work support in timed relation to the glazing tool. In the illustrated construction, such hydraulic means comprises a valve mechanism 90 similar in all respects to the valve mechanism 60. Fluid under pressure travels from the constantly operating pump '62 to the valve mechanism 90 through the pipe 64 and branch pipe 92, the latter entering the middl portion of the valve chamber and being directed therefrom through a pipe 94 to a cylinder head 96 whereby a piston 91 is instantly forced to the left (Fig. l) to operate rack member 98. As in the case of the tool-operating piston 30, the rack member 98 is provided with rack teeth which are constantly in mesh with the segmental gear I00 secured to a shaft I02 journaled in an oil-tight stationary casing I04. To an end of the shaft I02 outside of the casing is secured the lever arm I08 which is forked to embrace a collar IIO slidable on a post I I2 to the upper end of which is secured the work support 6. Interposed between the collar H0 and an enlarged part II4 of the post H2 is a heavy spring I I6. When the collar IIO, which is engaged by pins carried by the lever arm I08, is lifted by said lever arm the spring II6 is compressed and forced upwardly to effect upward movement of the post I I2 and hence of the table 6. In other words, the spring H6 serves as the actual pressure means by which the work piece is supported against the thrust of the tool 8. This same lever arm I08 is provided with pins I20 which engage in a slot I22 of a sleeve member I24 slidable on a second post I26, upward movement of the sleeve I24 having the effect of compressing a light spring I21 to effect upward movement of a work clamping and moving means which will be hereinafter described in detail.

As pointed out above, movement of the rack or piston member 98 to the left in Fig. 1 results in upward movement of. the work support 6 into cooperative relation with respect to the glazing tool 8. At the end of the upward movement of the work support 6, the feeler member I6 is lifted just before the work piece contacts the tool 8. Such lifting of the feeler member I6 results in downward movement of the controller 24 whereby an operative stroke of the tool 8 is initiated. As heretofore pointed out, the feeler I6 travels with the tool 8 in its operative stroke and reaches the edge of the work substantially at the same time as the tool, so that it drops off said edge of the work and initiates the return stroke of the tool as soon as the latter drops off the edge of the Work, this practically instantaneous response of the hydraulic means to the position of the feeler I6 being due to the extreme sensitivity of the valve mechanism 60. During this return stroke of the tool the table 6 is depressed, this result being attained through control of the valve mechanism 90 by the feeler I6. As soon as said feeler drops off the edge of the Work, the controller member 24 is lifted by the spring 25 with the result that a link I pivoted at I3I to the lower end of the rod 26 is moved upwardly about a pivot I32 stationary at that time. This upward movement of the link I30 has the effect of lifting a valve rod or stem I36 (connected to the link I30 by a pin I33 secured to the link I30 and operating in a grooved spool I35) slidable on the valve stem I36 thereby shifting the valve member inside of the valve chamber 90 in a direction to cause the pressure medium to move through the valve mechanism to a pipe I40 opening at its other end into a piston cylinder head I42 whereby the rack member or piston 98 is instantly operated in the reverse direction, that is, to the right in Fig. 1, whereby the work support 6 is lowered and with it the work clamping devices. It is pointed out that the spool I35 is yieldingly held against a collar I 31 pinned to the end of the valve stem I36 by a spring I39. At its other end, the spring I3'I presses against a block I59 fastened to the stem I36. During the interval that the work support 6 is lowered, the tool 8 returns to its extreme left position in Fig. 1 in its idle stroke.

While the valvemechanism controls the rack member or piston 98 for effecting movement of the work support 6 between work receiving and work presenting positions with respect tothe tool 8, the said valve mechanism 90 and the member 98 are also controlled in such manner as to vary the pressure with which a given work piece is pressed against the tool 8 during the operative stroke of the latter. It will be noted that the feeler member I6 is located closely adjacent to the tool 8. As it travels over the surface of the work piece with the tool 8 it responds to variations in the thickness dimension of the work piece in its path over the latter. The result is that the controller member 24 moves slightly in up-and-down directions corresponding to the movements of the feeler I6. Hence the hollow valve member in the valve mechanism 90 is shifted accordingly and thereby varies the flow of liquid under pressure through the pipe 94 to the piston cylinder 96 and hence varies the pressure by which the work support 6 presents the work piece against the tool 8.

When, for instance, a thin spot is contacted by the feeler I6, the controller membr 24 is lifted by the spring 25, with the result that link I30 is lifted about pivot I32, whereby valve stem I36 is moved upwardly together with the valve member in valve 66. Hence liquid flows through pipe I40 to the cylinder head I42, thereby moving rack member 98 to the right a, slight amount, causing downward movement of lever arm I08 and hence of. the work support 6. But a link I4I pivoted to lever arm Ii58-is also pivoted at'its other end to a lever I43 pivoted at I45 to the frame of themachine. The free end of lever I43 is pivoted to a link I I-1* pivoted on pivot pin I32 of link I35. Hence any downward movement of lever arm I68 and of the work support 6. will cause lowering of the valve stem I36 and hence of the movable valve member in valve 96 which is thus, returned to neutral position. In other words, the rack member 98 is hydraulically lock in the new position which puts a little less pressure on the spring II6 which supports and delivers the necessary pressure on the leather. By varying the tension of the spring II6 hydraulically, pressure on the work piece is varied in accordance with the thickness dimensions thereof. When feeler I6 dropped lower because of a thin spot, rod 26 moved upwardly and link L36 turned about I32 as a pivot to lift valve member in valve 96., thereby permitting flow of pressure medium through pipe M6 to lower the lever arm I06 and work support 6. But lowering of. arm I68 lowers lever I43 about pivot I45, thereby lowering; link I88 about pivot I3I which had been lifted when feeler I6 engaged the low spot. Hence link I66.- rocks about pin- I-3I and brings valvemember in valve 90 to neutral position with the piston 63 hydraulically locked against movement, thus maintaining upward pressure on spring Mo tosupport the table 6. This mechanism affords a very sensitive adjustment of the glazing tool to variations in the thickness dimension of the work piece in the path of the feeler and tool. In the illustrated construction, this pressure is slightly less for thinner portions of the work piece than it is for thicker portions thereof.

As a safety feature, for instance, if the operator does not center a skin properly, or if a skin is toolarge for the machine, the feeler [-6 may not drop downwardly at the end of its. stroke to the right. However, it is necessary to-reverse the stroke and to lower the table, otherwise the machine would be locked against further operation. Hence a link I! is pivoted to the lever 46 and to a bell-crank I53 through a slotted part I55of link I-5I the latter permitting a normal stroke of the tool 8 and feeler I6, after which the shoulder at the left end of the slot I55 will operate the bell crank I56. Operation of bell crank I53 lifts a link I53apivoted at its lower end to a block I59 fixedly secured to the stem I66 of the movable valve in the valvedevice 66.. Lifting of the valve member in valve- 96 sends liquid through pipe I46 and effects lowering of the work support, thus conditioning the machine for a succeeding operation.

As heretofore indicated, the illustrated machine preferably embodies work clamping and moving means, the purpose being to shift the work piece after each operative stroke of the glazing tool 8. This makes the machine automatic in itsoperations on a given piece of work,

whereas heretofore the operator had to shift the work piece between successive strokes of the operating tool. In the illustrated construction, the work clamping means comprises work clamping members I56, I52 (Fig, 2) carried by hubs I54 and I56, respectively, the said hubs being rotatably mounted upon the upper end of the post I26 and held against movement lengthwise of the post I 26- by collars I51. A spring I58. is connected to pins on both of the members I50, I52 to hold these members yieldingly toward each other. For co-operation with the work clamping members I56, I52 which are movable upwardly with the post I26, there is provided a pair of work clamping members I66, I62 carried by hubs I64- and I66, respectively, the said hubs being rotatable on a vertical stub shaft I 68 but being restrained against up-and-down movement. The work clamping members I60, I62 have connected therewith a spring III] which holds the members I 66, I 62 yieldingly toward each other.

It will be readily understood that the Work clamping members I50, I52 move upwardly and co-operate with the work clamping member I66, I62 well before the work support 6 presents the work piece to the tool 8. In fact, means is provided for rotating the work clamping members after they engage the work piece so as to shift .the latter over the surface of the work support 6 to present another portion thereof for the next stroke of the tool. At the end of the sidewise swinging movement of the work clamping members I56, I52 and I66, I62, the latter are operated to separate or recede laterally from each other so as to place that portion of the work piece between them under tension while the tool is operating. The means for accomplishing these operations will now be described.

As shown most clearly in Fig. 2, the hub I56 of the work clamping member I52 has a projecting ear III thereon to which is connected a link I86 having an opening in its, outer end for the reception of an upstanding pin I82 secured to the end of a link member I84 pivoted at the forward end of a slide member I85 (Figs. 1 and 2). By having the pin I82 of substantial length, the connection between the link I80 and the link member I84 is maintained at all times, that is, during upward and downward movement of the work clamping members on the post I26. Movement of the link member I84 to the rear in Fig. 1 will result in swinging the work clamping members in a clockwise direction (Fig. 3) to shift the work piece over the upper surface of the work support 6. This operation of the work clamping members I50, I52 will be better understood upon reading the following description of the clamping members I69, I62 which are also shown more clearly in the plan view of Fig. 3. In order that the upper work clamping members I66 and I62 may be positively rotated at the same time as the lower clamping members, the hub I66 of the work clamping member I62 is provided with an ear I186 (Figs. 2 and 3) to which is pivoted a link I81 in turn pivoted to the forward end of a link member I at the forward end of a slide member I91. Similarly, hub I64 (Fig. 2) has an ear I93 (Figs. 2 and 3) to which is pivoted a link I95 pivoted at its other end to lever I8'I. These slide members I85 and I9I are moved rearwardly in Figs. 2 and 3 to rotate the work clamping members after they have engaged the work piece. At the end of this swinging or rotating movement of the work clamping members, terminated by the upper member I52 coming into contact with a side edge of the table 6 (Fig. 3), they are caused to move away from each other in sets upon opposite sides of the table 6 to tension a portion of the work piece between them so that the work pieceis properly conditionedv for treatment by the glazing tool 8.

on the sleeve I24 until The described separating movement of the sets of work clamping members is accomplished through the operation of a lever mechanism most clearly shown in Fig. 3. Upon reference to Fig. 3 it will beobserved that the ear I86 on the hub I66 is movable about the shaft I68 and has pivoted Ito its end a lever member I81 to which is pivoted the short link I95 also pivoted to an ear I93 rigid with the hub I64 of the work clamping member I60. It will be clear that clockwis rotation of the lever I81 in Fig. 3 will result in straightening a toggle of which the link member I95 is the other member, the straightening of the toggle being accompanied by separrating movement of the work clamping members I60, I62 to tension a portion of the work piece. It is to be understood that the lower work clamping members I50, I52-are operated in the same vivay simultaneously with the upper members I60,

For operating the work clamping devices after they have engaged the work piece, there is preferably provided a hydraulic mechanism similar to that for operating the tool 8 and to that for operating the work support 6. This hydraulic mechanism comprises a valve mechanism 220 (Fig. 1) which is similar in all respects to the

valve mechanisms

60 and 90. In this case, fluid under pressure comes from the pump 62 by a pipe 222 and a branch pipe 224 opening into-the middle part of the valve casing of valve mechanism 220. The movable valve member inside the casing is controlled by a valve stem 226 having at its outer .end a roller 228 in contact with a flat surface 230 on the sleeve I24. When the sleeve I24 is moved upwardly by the lever arm I08, the roller 228 rides along the flat. surface 230 and also along a flat surface of a latch member 232. When the roller 228 drops off the lower end of the surface of the latch member 232, the valve stem 226 is projected to the left (Fig. l) by a spring 234. This movement of the valve stem and movable valve member inside 220 results in passage of the pressure medium under pressure through a pipe 240 to a piston cylinder 242 (Fig. 3) which contains a piston to operate a rack 243 in casing 244 similar in all respects to the rack 30 and to the rack 98 of Fig. 1.

In fact, the showing of the piston 38 and all its operating parts in Fig. 1 is also a disclosure of the pistonin cylinder 242 and of the rack 243 in casing 244. Movement of this piston and rack in the casing 244 operates a lever 250 (Fig. 1) which is connected by a link 252 to the pair of slide members I85, I9I which in turn are connected at their front ends through links I84 and I90 to the lower and upper work clamping members I52 and. I62, respectively, to operate the latter in the two successive movements described above. These movements of the clamping members are accomplished before the work support presses the work piece against the tool 8.

There has been described in the preceding paragraph the manner of operating the valve stem'226 (Fig. 1) which carries the roller 228,.1t being stated that upward. movement of the sleeve I24 on the post I26 results finally in the dropping of the roller 228 off of the lower end of a flat surface on the latch member 232. During the subsequent downward movement of the sleeve up a slanting surface 210 it lifts the spring pressed latch member 232 and reappears on the fiat surface in the position shown in Fig. 1. It W111 be understood, of course, that downward movement I24, the roller 228 runs of the post I26 and of the sleeve I24 is accompanied by downward movement of the lower work clamping members I50, I 52. During this downward movement the valve stem 226 is moved to the right, thus effecting a reverse movement of the valve member in the valve mechanism 220 with the result that pressure medium under pressure flows out through a pipe 212 whereby such pressure medium under pressure is introduced into a piston cylinder head 214 (Fig. 3) to move the rack 243 in casing 244 in the direction to swing the work clamping members to their initial positions, in which they are ready to clamp a work piece upon a subsequent upward movement of the lower clamping members.

When the machine is at rest, the valve member in valve device is down so that liquid may enter cylinder head 96 to start lifting of the work support 6.. Also valve member 66 in valve device 60 is over to the left in Fig. 1, while the machine is at rest, to hold the tool 8 over to the left while table 6 is down and while the latter is rising. Contact of the work piece with the feeler I6 starts operation of the tool 8. Also the work clamping members are held in the position of Fig. 1 by the rack or piston member 243 under control of the valve 220 as conditioned by the position of the valve stem 226 and roller 228 (Fig. 1).

To start the machine in operation, the operator steps on a tread portion 290 of a treadle shown in Fig. 2 of the drawings with the result that a toggle 292 is broken thereby lowering a spring loaded relief valve member 294 in a valve chamber 296. Such movement 'of the valve 294 stops the flow of liquid through a pipe 300 to the sump 10 with the result that liquid from the pump 62 is forced to pass upwardly through the pipes 64 and 224 to the

valve mechanisms

60, 90 and 220, respectively, whereby the

racks

30, 98 and 243, respectively, are actuated in timed relation to each other. As soon as the table supporting post II2 moves upwardly following the closing of the valve in valve device 296, a lever 3) (Fig. 2) is rocked by a spring 3I2 to project a latch 3I4 into a notch 3I6 in a member 3I8 fixed to the treadle, the result being that the treadle is locked with the valve in valve casing 296 in position to maintain the machine in operation while it is treating a given piece of work and until the treadle is moved in the opposite direction by the foot of the operator it being understood in this connection that the toggle 292 will remain in broken condition in the brief intervals during which the work support is in lowered position. When the work support is in the lower position the treadle may be moved to the position shown in Fig. 2 to straighten the toggle and stop the operation of the machine. The toggle moves beyond center to hold the inoperative position shown in Fig. 2.

In operating the illustrated machine to glaze a kid skin, for instance, the latter is placed on the work support 6 with the center point in the backbone line of the skin directly under the tool 8. As the work support and lower work clamping members rise toward the tool, the work clamping members engage the skin and shift it laterally in the manner described before the work support presses the skin against the tool. Not only is the skin shifted but it is tensioned by a separating movement of the work clamping members before it is pressed against the tool. As

' the feeler I6 moves upwardly through pressure ates an operative stroke of the tool which is terminated as soon as the tool drops off the edge of the skin. The tool is then returned in its idle stroke which takes place while the work support is depressed along with the lower work clamping members. These members then rise again to engage the skin in its new position and to shift and tension it prior to the next working stroke of the tool. These operations are repeated until all portions of the skin have been successively presented for treatment. It is to be understood, of course, that a supplemental work support may be provided which will be stationary in the plane of the support 6 when the latter is in its raised position, this supplemental work support being of a size to furnish support for those parts of a hide or skin which normally would extend beyond the support 6, this arrangement insuring that the hide or skin will not be displaced by gravity in the intervals between the work clamping and shifting operations.

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 sheet material, a work support, a tool movable in opposite directions relatively to a work piece on said support, said tool having an operative stroke in one direction and an idle stroke in the opposite direction, means for reciprocating the tool in its idle and operative strokes, and means controlled directly by the work piece with reference to a linear dimension thereof to terminate the operative stroke of the tool according to the length of said dimension.

2. In a machine for operating on sheet material, a Work support, a tool movable in opposite directions relatively to a work piece on said support, said tool having an operative stroke in one direction and an idle stroke in the opposite direction, means for reciprocating the tool in its idle and operative strokes, and detector means controlled directly by the work piece with reference to a linear dimension thereof to initiate return of the tool in its idle stroke when said tool drops off an edge of the work piece.

3. In a machine for operating on sheet material, a work support, a tool movable in opposite directions relatively to a work piece on said support, said tool having an operative stroke in one direction and an idle stroke in theoppesitedirection, means for reciprocating the tool in its idle and operative strokes, and work-controlled detector means movable with the tool to determine the length of the operative stroke of the tool whereby the latter is reversed when it passes oif an edge portion of the workpiece.

4. In a machine for operating upon sheet material, the combinationwith a work support and a tool, of power operated meanssfor imparting to said tool repeated movements in one direction in operating upon a work piece on said support, and work-controlled means for terminating each operative movement of the tool as soon as "the tool is moved out of engagement with the work piece.

5. In a machine for operating on sheet material, a work support, a tool for operating on a work piece, means for reciprocating the tool in its idle and operative strokes, and Work-controlled detector means spaced from said tool in the-direction of its operative-stroke and 'movable-therewith to detect the approach of said tool with respect to an edge portion of the work piece and to initiate return of the tool in its idle stroke as soon as the latter drops off the edge of the work piece.

6. In a machine for operating on sheet material, a work support, a tool for operating on a work piece, means for reciprocating the tool in its idle and operative strokes, work-controlled detector means to control the operative stroke "of the tool whereby the tool is reversed when the latter passes off an edge portion of the work piece, and means for causing relative separating movement of the tool and Work support the instant the tool drops off said edge portion of the work piece whereby the return stroke of the tool becomes an idle'stroke.

7. In a machine for operating on sheet material, -a work support, a tool for-operating on a work piece, means for reciprocating the tool in its idle and-operative strokes, work-controlled detector means to' control the operative stroke of the tool whereby the latter is reversed when it passes off an edge portion of the work piece irrespective of the length of such operative stroke, and means for lowering the work support the instant-the tool passes on said edge -'of the work piece whereby the return stroke of the tool becomes an idle stroke.

8. In a machine for operating on sheet material, a work support, a tool for operating on a work piece, means for reciprocating the tool in its idle and operative strokes, detector means directlycontrolle'dby the work piece and operative to control the operative stroke of the tool whereby the tool is reversed when it passes off an edge portion of the work piece, said reciprocating means including a piston for operating the tool inane-direction, and hydraulic means for operating the piston to move the tool at a uniform rate of travel over the surface of the work piece.

9. In a machine for operating on sheet material, a work support, a tool movable in a plane above the work support for operating on a work piece on said support, means for moving the work support toward and from the operative plane of the tool, detector means directly responsive to the presence and absence of a work piece on the work support and operative to control the operative stroke of the "tool, a piston device for operating the tool, and hydraulic means under the control of said detector means for operating the piston device to move the tool at a uniform rate of travel over the surface of the work piece.

10. In a machine for operating on sheet material, a work support, a tool movable in a plane above the work support for operating on a work piece on said support, means for causing relative approaching and separating movements between the work support and tool during movements of the tool in it's operative and idle strokes, detector means directly controlled by the work piece and operative to control'the operative stroke of the tool whereby the tool is reversed when the latter passes off an edge portion of th work piece, a piston device including a rack for operating the 'tool, and hydraulic means under the control of said 'detector means for reciprocating the piston device alternatively in opposite directions, the relative separating movement of the work support and tool being timed to produce the idle 'stroke of the tool with respect to the workpiece.

11. In a machine for operating on sheet material, a tool,-a work-supportfora workpiece duringtreatment thereof, means for moving the tool back and forth in a plane above the work support, a feeler device movable with the tooland piece before the tool reaches such edge portion, means controlled by the feeler device to reverse the direction of movement of the tool as soon as the tool drops off the edge of the work piece, and means to cause a relative separating movement between the work support and tool during the return movement of the tool so that such return movement is an idle stroke of the tool preparatory to a succeeding operative stroke'thereof.

12. In a machine for operating upon sheet material, a'work support, a tool movable over the surface of a work piece on. the 'work support, means for moving said tool back and forth overthe surface of the work piece, power means for causing relative approaching and separating movements of the work support and tool, and detector means operating in advance of the tool in the direction of its operative stroke to control the said power means in accordance with the thickness of the work piece in the path of the tool, whereby the pressure of the tool on the work piece may be suited to various portions thereof.

13. In a machine for operating upon sheet ma- "terial, a work support, a tool, power means to move the tool over the surface of a work piece on the work support, hydraulic means comprising a valve mechanism for causing relative appreaching and separating movements between thework support and tool, and a feeler device movable in advance of the tool during its work treating movement and operative to respond to variations in the thickness of the work piece in the path of the feeler and tool, said feeler device having connections to control said valve mechanism whereby the pressure between the Work support and the tool is adjusted to the varying thickness of the work piece during movement of the tool over the work piece.

.14. In a machine for operating upon sheet material, a work support, a tool movable in a plane above the surface of awork support to operate on a work piece on the support, power means for causing relative approaching movement between the work support and tool, power means for moving the tool back and forth in its operative and idle strokes, a feeler device contacting the work piece and movable in advance of the tool in its operative stroke, and connections between the feeler member and both of said power means whereby the feeler device controls not only the length of the operative stroke of the tool but also the pressure between the work support and tool in accordance with variations in the thickness of the work piece in the path of the tool.

15. In a machine for operating upon sheet material, a work support, a tool for treating a work piece while the latter is backed by the support, hydraulic means comprising a piston device have ing operative connections with said tool, cylinders for slidably receiving the opposite ends of said device, a valve mechanism to control the passage of pressure medium alternately to said.

cylinders whereby the piston device and the tool are reciprocated, a feeler device contacting the work piece and movable in advance of the tool in thedirection of its operative stroke, and connections between the feeler device and said valve mechanism to control the latter whereby the piston device and hence the tool are reversed in their direction of movement when the feeler drops off an edge of the work piece.

I 16. In arnachine for operating upon sheet material, awork support, a tool to operate on a work piece backed by said work support, power means for causing relative approaching and sep-,

arating movements between the work support and tool, power means for moving the tool along a given path on the surface of the work piece on the work support to treat that portion of the work piece in the path of the tool, a pair of work clamping members at each side of the Work support, one member of each pair being above and the other below the plane of the work piece on said support, thus providing an upper and a lower set of work clamping members, means for causing the work clamping members to engage a work piece placed between them, and power means operating in timed relation to the two first-mentioned power means to move the pairs of work'clamping members away from each other on opposite sides of the work support to place that portion of the work piece lying between the pairs of members under tension prior to each of the operative strokes of the tool.

17.- In a machine for operating upon sheet material, a work support, a tool movable from a middle portion of a work piece to a margin thereof, power means for reciprocating the tool in its operative and idle strokes, a pair of work clamping members on each side of the work support, one of each pair being above and the other below the work supporting surface thereof, thus providing an upper and a lower set of work clampingmembers, power means for moving one set of work clamping members toward the other whereby the work piece is clamped by said clamping members, means for rotating the clamping members to shift the work piece in one direction over the surface of the work support prior to the operation of the tool, and means for movingthe pairs of clamping members on each side of the work support away from each other sufiiciently to place the work piece under tension prior to the operation of said tool.

18. In a machine for operating upon stretchy sheet material, a work support, a tool movable from a middle portion of a work piece to a margin thereof, a pair of work clamping members on each side of the work support, one of each pair being above and the other below the work supporting surface thereof, thus providing an upper and a lower set of work clamping members, power means for moving one set of work clamping members toward the other whereby the work piece is clamped by said clamping member, power means for rotating the clamping members to shift the work piece in one direction over the surface of the Work support prior to the operation of the tool, means operating in timed relation to the rotating means for moving the work support in a direction to press the work piece against the tool, means for causing a relative separating movement of the pairs of clamping members on each side of the table to place the ,work piece under tension just prior to the pressing of the work piece against the tool, and means for operating the tool to treat the work piece while the latter is held under tension by the Work clamping members.

' 19. In a machine for operating upon stretchy sheet material, awork support, a tool movable from a middle portion of a work piece to a margin thereon, a pair of work clamping members on each side of the work support, one of each pair being above and the other below the work supporting surface thereof, thus providing an upper and a lower set of work clamping members, power means for moving one set of work clamping members toward the other whereby the work piece is clamped by said clamping members, means for rotating the clamping members to shift the work piece in one direction over the .surface of the worksupport prior "to the operation of the tool, power means for moving the work support in a direction to press the work piece against the tool, means for causing a separating movement of the pairs of clamping members on each side of the work support to place the work piece under tension just prior to the pressing of the work piece against the tool, means for operating the tool to treat the work piece while the latter is held by the work clamping members, means for lowering the work support and at the same time returning the work clamping members to their initial positions whereby the Work piece is released by both the work support and the work clamping members, the subsequent upward movement of the worksupport and of the lower set of work clamping members being accompanied by reengagement of the work piece by the work clamping members together with the rotary movement of the work "clamping members to reposition the work before the succeeding operation of the tool.

20. In a machine for glazing leather, a glazing tool, a Work support movable to back a work piece against the thrust of the tool, means for moving the tool back and forth in a plane above the work support, a feeler device movable with the tool and arranged to drop off an edge portion of the work piece before the tool reaches such edge portion, means controlled by the feeler member to reverse the direction of movement of the tool as soon as the latter drops off the edge of the work piece, and means to retract the work support during the return movement of the tool so that such return movement is an idle stroke of the tool preparatory to a succeeding operative stroke thereof.

21. In a machine for operating upon hides and skins, a work support, a tool movable over the surface of a work piece on the work support, power means for reciprocating said tool back and forth in a plane above the surface of the work support, means for moving the work support toward and from the tool, and a feeler device contacting the work piece in advance of the tool in the direction of its operative stroke to control said work support moving means in accordance with the thickness of the work piece in the path of the feelermember and tool.

22. In a machine for operating upon hides and skins, a work support, a tool movable over the surface of .a work piece on the work support, power means for reciprocating said tool back and forth in a plane above the surface of the work support, hydraulic means comprising a valve mechanism for moving the work support toward and from said tool, and a feeler device movable in advance of the tool during its operative stroke and operative to respond to variations in the thickness of the work piece in the path of the feeler and tool, said feeler member having connections to control said valve mechanism Whereby the work support is adjusted to the varying thickness of the work piece during the movement of the tool in its operative stroke.

23. In a machine for treating hides and skins, a work support, a tool movable in a plane above the surface of a work support to operate on a.

work piece on the support, power means for moving the Work support toward and from said plane, power means for moving the tool back and forth in its operative and idle strokes, a feeler device contacting the work piece and movable in advance of the tool in its operative stroke, and connections between the feeler device and both of said power means whereby the feeler member controls not only the length of the operative stroke of the tool but also the position of the work support in accordance with variations in the thickness of the work piece in the path of the tool over the latter.

24. In a machine for operating upon hides and skins, a work support, a tool for treating a work piece while the latter is backed by the support, hydraulic means comprising a piston device having operative connections with said tool, cylinders for slidably receiving the opposite ends of said piston device, a valve mechanism to control the passage of pressure medium alternately to saidcylinders, whereby the piston device and the tool are reciprocated, a feeler device contacting the work piece and movable in advance of the tool in the direction of its operative stroke, connections between the feeler device and said valve mechanism to control the latter whereby the piston device and hence the tool are reversed in their direction of movement when the feeler drops off an edge of the work piece, hydraulic mechanism to move the work support toward and from the tool, and connections between said feeler member and the hydraulic mechanism to control the movement of the work support in accordance with the thickness of the work piece in the path of the feeler member. W

25. In a machine for operating upon hides and skins, a work support, a tool movable from a middle, portion of a work piece to a margin thereof, hydraulic means for reciprocating the tool in its operative and idle strokes, a pair of work clamping members on each side of the work support, one of each pair being above and the other below the work supporting surface thereof, thus providing an upper and a lower set of clamping members, power means for moving one set of work clamping members toward the other whereby the work piece is clamped by said clamping member, and hydraulic mechanism operating in timed relation to the hydraulic means to move the clamping members to shift the work piece in one direction over the surface of the work support prior to the operation of the tool.

26. In a machine for operating upon hides and skins, a work support, a tool movable from a middle portion of a work piece to a margin thereof, hydraulic means for reciprocating the tool in its operative and idle strokes, a pair of work clamping members on each side of the work support, one of each pair being above and the other below the work supporting surface thereof, thus providing an upper and a lower set of clamping members, power means for moving one set of work clamping members toward the other whereby the work piece is clamped by said clamping members, means to move the clamping members to shift the work piece in one direction over the surface of the work support prior to the operation of the tool, and hydraulically operated mechanism operating in timed relation to said bydraulic means to move the clamping members on each side of the work support away from each other sufficiently to place the work piece under tension prior to the operation of said tool.

27. In a machine for operating upon hides and sk ns, a work support, a tool movable from a middle portion of a work piece to a margin theremembers, means to move the clamping members to shift the work piece in one direction over the surface of the work support prior to the operation of the tool, hydraulic mechanism operating in timed relation to said hydraulic means for causing relative approaching and separating movements between the work support and tool in a direction to press the work piece against the tool, and means for causing a separating movement of the clamping members on each side of the table to place the work piece under tension just prior to the pressing of the work piece against the tool, the meansfor operating the tool being operative while the work piece is held by the work clamping members.

28. In a machine for operating upon hides and skins, a work support, a tool movable from a middle portion of a work piece to a margin thereon, hydraulic means for reciprocating the tool in its operative and idle strokes, a pair of work clamping members on each side of the work support, one of each pair being above and the other below the work supporting surface thereof, thus providing an upper and a lower set of clamping members, hydraulic means for moving one set of work clamping members toward the other whereby the work piece is clamped by'said clamptimed relation to the two hydraulic means above mentioned for causing a separating movement of the clamping members on each side of the table to place the work piece under tension just prior to the operation of the tool, said means for operating the tool being operative to treat the work piece while it is held under tension by the work clamping members, and means for lowering the work support and at the same time returning the work clamping members to their. initial positions, whereby the Work piece is released by both ing members, means for moving the clamping 4 members to shift the work piece in onedirection over the surface of the work support prior to the operation of the tool, the work support being movable in a direction to press the workpiece against the tool, hydraulic means operating in the work support and the work clamping members, the subsequent upward movement of the 7 work support and of the lower set of the work clamping members being accompanied by reengagement of the work piece by the work clamping members together with a rotary movement of the work clamping members to reposition the work before the succeeding operation of the tool.

29. In a machine for operating upon sheet material, the combination with a work support and a tool, of power operated means for imparting to said tool repeated baok-and-forth' movements in operating upon a work piece on said support, and work-controlled means for reversing that movement of the tool which ends with the latter dropping off the edge of the'work piece, said work-controlled means becoming operative to reverse the tool as soon as the latter drops off the Work piece.

30. In a machine for operating on sheet material, a tool, a Work support for .a work piece during treatment thereof, means for moving the tool back and forth in a plane above the work support, a feeler device movable with the tool and arranged to drop off an edge portion of the work piece before thetool reaches such edge portion, and means controlled bythe feeler device to reverse the direction of movement of the tool as soon as the tool drops oif the edge of the work piece.

ERASTUS E; WINKLEY.