US3276230A

US3276230A - Leather working machines

Info

Publication number: US3276230A
Application number: US397212A
Authority: US
Inventors: Arthur H Horn
Original assignee: CHAS H STEHLING CO
Current assignee: CHAS H STEHLING CO
Priority date: 1964-09-17
Filing date: 1964-09-17
Publication date: 1966-10-04
Anticipated expiration: 1983-10-04

Description

Oct. 4, 1966 A. H. HORN 3,276,230

LEATHER WORKING MACHINES Filed Sept. I7, 1964 5 Sheets-Sheet l PRESSURE SOURCE I, mhzw yt i Arthur HHnr V A 32% A "m.

I 3 7 m I. J

Oct. 4, 1966 A. H. HORN 3,276,230

LEATHER WORKING MACHINES Filed Sept. 17, 1964 5 Sheets-Sheet 2 HEAD AND NECK PORTlON F QONT FLANK PORTION Jmdnw 01/ T2 bur .H. H1: rn

, Oct. 4, 1966 A. H. HORN 3,276,230

LEATHER WORKING MACHINES Filed Sept. 17, 1964 3 Sheets-Sheet 5 United States Patent 3,276,230 LEATHER WORKING MACHINES Arthur H. Horn, Waukesha, Wis., assignor to Chas. H.

Stehling Co., Milwaukee, Wis., a corporation of Wisconsm Filed Sept. 17, 1964, Ser. No. 397,212 15 Claims. (CI. 69-42) This invention relates to improvements in leather work ing machines of the type having a rotatable work performing roll'land a rotatable backup roll by which a piece of leather to be worked is forcefully urged against the work performing roll and moved past the same, and refers more particularly to leather shaving machines.

Leather shaving machines, as they have been used in the industry for many years, consist of a bladed work performing or shaving cylinder or roll mounted in the frame of the machine for rotation on a fixed axis, and a backup roll mounted on a carrier with its axis parallel to that of the shaving cylinder. The carrier is movable on the frame in directions to translate the backup roll toward and from the shaving cylinder at the will of an operator, who controls the position of the carrier by means of a foot pedal. When the pedal is momentarily depressed, the carrier moves the backup roll to, and holds it in, a machine-open position wherein the rolls are spaced apart by a substantial distance so that a shaved piece of leather can be withdrawn from between the rolls and the leading edge of a new piece of leather to be shaved can be inserted between them. With a leather piece introduced into the machine, the operator again depresses the pedal momentarily, and this causes the carrier to translate the backup roll toward the shaving cylinder or roll and to a machine-closed position in which the surfaces of the rolls are spaced apart a small distance. The distance between the rolls intheir machine-closed relationship is somewhat less than the thickness of the leather piece to be shaved, so that the leather between the rolls is tightly i-gripped and pressed against the shaving cylinder as it is drawn into the machine. 7

' T he shaving cylinder rotates at a substantially high speed, which may be in the neighborhood of 2000 rpm. .The backup roll is also power driven, but it turns at a substantially slower speedin the neighborhood of 40 "r.p.m.so that it resists the advancing force which the shaving cylinder exerts upon the piece while-at the same time providing for more or less controlled progress of the piece relative to the shaving cylinder.

' While shaving is done on different kinds of leather for instance, calf skin, as well as leather made from cow hldeS'r-it is the latter whch-constitutes the bulk of the inarket and is most widely used by shoe manufacturers.

For many reasons it is important that the leather used for the uppers of shoes be of uniform thickness or, in the parlance of the leather working industry, of the same weight. A tanner will speak of three and one-half (3 /2) ounce leather, four (4) ounce leather, and so on, and in each case he means that a piece roughly one square foot in area will weigh so many ounces, depending upon the thickness of the leather; and since each ounce corresponds to about one sixty-fourth ,4 of an inch, four ounce leather is about one-sixteenth 6& of an inch thick. But the important thing to the shoe manufacturer is that the thickness be uni-form.

Cow hides are generally larger than can conveniently be handled in the tannery. Hence they are cut in two down the backbone, and each resulting half-hide is referred to by the tanner as a side. Cow hides are also substantially thicker than leather used for shoe uppers. The leather obtained from cow hides, therefore, is split flatwise into at least two, and sometimes more pieces. Since 3,276,230 Patented Oct. 4, 1966 "ice these pieces, which result from the splitting ope-ration, are only roughly uniform in thickness, they must be shaved to gain the required uniformity.

The splitting and shaving operations take place after the hide has been tannedusually chrome tannedso that it is then technically leather, but at this stage, though it has been passed through a wringer, the leather is still wet and somewhat slippery. One edge of each side of leather is straight, its remaining edges have an irregular contour; and one end portion of this side of leather is the head and neck area and the other end portion is the rump area.

Heretofore it was impossible for the tanner to obtain uniformity in thickness-or weight, as the tanner expressed it-throughout the entire area of a side of leather. Regardless of how expertly the shaving operation was done, the head and neck area, and often the front flank area of the side, was lighter than the rest of the piece. Since these areas of less than desired thickness constitute a fair proportion of the whole sides, shoe manufacturers for years have besieged the tanners with requests for better thickness control; and with the advent of plastic shoe upper material in which there is no problem of maintaining uniformity in thickness, the need for finding some way of assuring uniform thickness for the entire side became imperative. To go on with the existing situation was economically unfeasible.

This invention has met the demand. It follows, therefore, that the purpose and object of this invention is to provide a leather shaving machine with which an operator can shave an entire side of leather to exactly the same weight or thickness.

The invention grew out of the discovery or recognition of why it was impossible to shave all portions of a side of leather to the same thickness with shaving machines heretofore available, but before this can be explained it is necessary to have a clear understanding of just what takes place as the shaving operation proceeds.

As in most leather working machines, a piece of leather being shaved is stretched in opposite directions as it enters the machine. The tanner calls this putting ou This putting out is necessary to assure the piece being flat and free from folds as it is acted upon by the work performing roll or cylinder of the machine. In a shaving machine it is the cutting blades on the shaving cylinder which do the putting out, and for this purpose these blades are spirally arranged and pitched in opposite directions from the midpoint of the cylinder to its ends. Thus, as the cylinder revolves, the blades exert a pull on the piece of leather longitudinally of the cylinder and towards its opposite ends, with the net result that the piece is placed under considerable tension.

Most important, though, from the standpoint of this invention, is the fact that the stretching of the leather reduces the thickness of the portion thereof being acted upon by the shaving cylinder. The wider the piece, the greater will be the tension thereon and the thinner will be the part being shaved. This follows from the fact that a wide piece is acted upon by more blades than a narrow piece.

Since increased tension results in .a corresponding reduction in thickness, it is therefore safe to conclude that the wider portions of a side of leather have less shaved off than the narrower portions, and-inasmuch as the head and neck portion is considerably narrower than the body portion of a side-the head and neck portion and any other narrow part of a side fed into the machine would be shaved lighter, i.e. would have more shaved off than the rest of the hide. Consequently, when the leather recovered from its stretched condition and regained its original thickness minus the amount shaved oif, which takes place the instant the leather is released 3 from the grip of the rolls, the head and neck portion was thinner than the remainder of the side.

The foregoing no doubt explains why it was impossible to achieve uniformity in thickness with the shaving machines of the past, but an additional factor probably resides in the fact that the leather of the head and neck portion is less dense than that of the remainder of the side, and therefore apparently does not recover fully from its stretched state. But whatever the full and complete explanation might be, it was a fact that if the entire side of leather was shaved to the same weight, i.e. the spacing between the backup roll and the shaving cylinder was kept constant during the shaving of the entire side, the less dense head and neck area ended up too light.

The solution to the problem thus resided in finding some way of shaving the narrower and less dense head and'neck area lighter, which meant providing means by which the operator can control the spacing between the backup roll and the shaving cylinder, while the machine is acting on the leather piece, and preferably do so without requiring the operator to use his hands which must be free to straighten out and guide the piece into the machine. Again, this invention meets this objective.

Stated in another way, it is an object of the present invention to provide means in a leather shaving machine by which an operator is enabled to compensate for the varying width and density of a leather piece as it passes through the nip of the shaving and backup rolls, by shaving the narrow less dense portion of the piece heavier than the remainder thereof, and smoothly tapering or blending in the heavier and lighter shaved areas so that, as the leather recovers from its stretched condition, all areas of the shaved side of leather will have the same thickness or weight. The economic saving which results from this uniformity and the consequent useability of the entire side of leather is appreciably significant.

Those skilled in the art will recognized that the principles of the present invention are applicable to other types of leather working machines than the shaving machine herein described for purposes of illustration, and in particular to buffing machines.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIGURE 1 is a fragmentary vertical sectional view of a leather shaving machine, showing those portions of the machine with which the present invention is concerned; FIGURE 2 is a fragmentary view taken on substantially the same plane as FIGURE 1 but drawn to an enlarged scale and showing the compensating means of the present invention in more detail;

FIGURE 3 is a fragmentary front elevational view, with portions broken away and shown in section, of the part of the machine shown in FIGURE 2;

' FIGURE 4 is a fragmentary side view, on an enlarged scale, of part of the structure shown in FIGURE 2;

FIGURE 5 is a diagram showing the foot pedal controlled drive mechanism by which the compensating adjustment of the backup roll is effected; and

FIGURE 6 is a plan view of a typical side of leather.

Referring now to the accompanying drawings, the numeral 5 designates generally the fixed frame or base of a leather shaving machine embodying the principles of this invention, upon which are carried a work performing or shaving cylinder or roll 6 and a backup roll 7 which holds the leather against the shaving cylinder. Both rolls are power driven, their axes are parallel and they are relatively translatable toward and from one another.

As is conventional, the shaving cylinder or roll 6 is journaled in bearings mounted directly in the fixed frame of the machine, and its work performing surface is formed by the edges of relatively closely spaced spiral blades which encircle the cylinder and are pitched in opposite directions from the center of the cylinder towards its ends. Suitable power means (not shown) drives the shaving cylinder at high speed in the direction to cause its blades to stretch the leather in opposite directions as the blades shave its surface. The edges of the spiral blades are kept sharp by a grinding wheel (not shown) which travels back and forth along the length of the shaving cylinder during operation of the machine.

Relative translatory motion between the rolls is provided for by means of a yoke-like generally upright carrier 9, upon the upper portion of which the backup roll 7 is journaled. The carrier 9 is medially pivoted on the frame by means of coaxial trunnions 10 on the opposite sides of the carrier. At its top the carrier 9 also mounts a small horizontal feed table -11 which projects toward the front of the machine, and a feed roll 12 which is journalled on the carrier between the table and the backup roll 7 with its axis parallel to that of the backup roll. The feed roll 12 and backup roll 7 are driven by suitable power means (not shown) for rotation in synchronism at a speed substantially slower than that of the shaving cylinder so that the table 11 and the feed roll 12 cooperate to provide means for introducing the leading edge of the piece of leather to be shaved into the nip of the backup roll and the shaving cylinder.

As in prior leather shaving machines, the carrier translates the backup roll between a machine-open position, in which the rolls 6 and 7 are spaced apart by a substantial distance, and a machine-closed relationshipv (shown in FIGURE 1) in which the distance between the adjacent surfaces of the backup and shaving rolls is slightly less than the thickness of a piece of leather to be worked.

At the will of an operator, the carrier can be swung between its machine-open and machine-closed positions by means of an eccentric actuating cam 14 which is rotatable on an axis that is fixed with respect to the frame and which is at all times engaged by a cam follower roller 15 mounted on the bottom of the carrier. The carrier is biased, as by tension springs 16 (only one of which is shown), in the direction to swing its bottom rearwardly, and the follower roller 15 is thus maintained in engagement with the actuating cam 14.

Through friction clutch drive means (not shown) torque is constantly applied to the actuating cam 14 in the clockwise direction in FIGURE 1. Normally, however, a releasable latch means 17 prevents the cam from being rotated by the clutch and holds the cam in one or the other of a pair of defined angular positions which are apart and which correspond to the machine-open and machine-closed positions of the carrier. Momentary depression of a pedal 19 disengages the latch means 17 and releases the actuating cam for rotation from one to the other of its two positions.

The latch means 17 for stopping and holding the actuating cam 14 in its defined angular positions comprises a ratchet wheel 20 that is fixed with respect to the actuating cam for rotation therewith, and has two diametrically opposite teeth or abutments 21 on its periphery; a pawl 22 yieldingly held in engagement with the periphery of the ratchet wheel; and a generally vertical lifting link 23 which provides a peculiar motion transmitting connection between the pawl 22 and a medially pivoted generally horizontal lever 24 on the front end of which the pedal 19 is mounted.

Near its rear end the pawl 22 has a pivotal connection 25 with the fixed frame, so that the nose of the pawl is free to swing up and down, toward and from a latching position in which it engages one or the other of the abutments 21 on the ratchet wheel 20 to hold the actuating cam 14 against being rotated by the friction clutch. A tension spring 26, reacting between the fixed frame and the pawl, biases the latter downwardly to its latching position. It will be seen that momentary lifting of the pawl to raise its front end, i.e., its nose, clear of the adjacent abutment 21 on the ratchet wheel will permit the cam 14 and the ratchet wheel 20 to rotate through 180, whereupon the other abutment 21 on the natchet wheel will collide with the nose of the pawl. To this end, the lifting link 23 has its upper end pivoted, as at 27, to the medial portion of the pawl and its lower end normally in position to be engaged and lifted by therear end of the lever 24 as the latter is rocked by depression of the pedal.

Since the disengagement of the pawl from the ratchet wheel should be only momentary, upward motion of the link is accompanied by rearward motion of its lower end out of the path of the lever 24. This rearward displacement ofthe link 23 is produced by a forwardly facing cam surface 28 formed by a notch in the front edge of the link in coaction with a fixed sidewardly projecting pin 29 on the frame. A compression spring 30 yieldingly maintains the cam surface 28 engaged with the pin 29.

In the normal free position of the pedal 19 to which it is biased by a tension spring 31, the rear end portion of the lever 24 is engaged under the bottom of the lifting link 23, as shown in full lines in FIGURE 1, but when the pedal is depressed to swing the rear end of the lever 24 upwardly and raise the lifting link, the action of the cam 28 swings the link rearwardly clear of the rear end of the pedal lever 24, whereupon the link drops, permitting the pawl 22 to be snapped down by its spring 26 into the path of the oncoming abutment 21. When the pedal 19 is released, the rear end of pedal lever 24 moves down along the front face of link 23 cam fashion, swinging the latter rearwardly until the pedal lever descends to the point at which the lower end of link 23 can swing back over it in response to the bias of its spring 30.

Because leather must be shaved to different Weights, i.e. difierent thicknesses, means are customarily provided in leather shaving machines for manually adjusting the spacing between the backup roll and the shaving cylinder in their machine-closed relationship, such adjustment being performed when no leather is in the machine, In the machine illustrated, this adjusting means comprises a pair of arms 32 which constitute the lower portion of the carrier and are pivoted to the remainder of the carrier to have limited swinging motion relative thereto about an axis parallel to the common axis of the trunnions 10. The cam follower roller is journaled on the lower ends of these arms; hence by swinging the arms about their mounting the spacing between backup roll 6 and shaving cylinder 7 in the machine-closed position of the carrier, can be preset. To enable the arms to be swung forward or back, their upper ends are keyed to a shaft 33 that is journaled in the carrier proper, and has a worm wheel 34 fixed thereto. The worm wheel meshes with a Worm 35 the shaft of which is journaled in bearings fixed in the carrier proper, and through suitable reduction gearing 37 the worm shaft can be adjustingly rotated to slowly turn the worm wheel 34 and swing the arms 32 forward or back. As will be well understood by those skilled in the art, the gearing 37 can be manually rotated 'or driven by an electric motor suitably controlled to bring about the desired minute swinging adjustment of the arms 32 as needed to set the machine for shaving to any selected weight, within the capacity of the machine.

The structure described to this point is generally conventional, and, in this respect it is noteworthy that the present invention in nowise conflicts with the heretofore accepted and proven construction of shaving machines or the conventional manner of their adjustment and use.

As pointed out hereinbefore, the demand for uniform thickness in the leather made from cow hides and used for shoe uppers has plagued the tanning industry for years. The problem seemed hopeless. However, with this invention the demand can and is being satisfied. It is accomplished through the provision of means whereby the spacing between the backup roll and the shaving cylinder can be adjusted by the operator while the shaving operation is in progress to cause the machine to shave the narrow less dense head and neck areas of a side of leather heavy, i.e. thick, and the wider and denser areas of the leather, light.

To this end the shaft 39 by which the cam follower roller 15 is mounted at the lower end of the carrier 9 has a medial portion 40 on which the roller is journaled and coaxial end portions that are eccentric to the portion 40, and by which the shaft is rotatably mounted in the legs 32. Hence, by turning the shaft 39 one way, the axis about which the roller 15 revolves moves closer to the axis about which the actuating cam 14 turns, and vice versa, with the result that the backup roll is moved away from and returned to its preset spacing from the shaving cylinder. To turn the shaft 39, a double acting pneumatic cylinder 41 is mounted on the lower portion of the carrier proper and has its ram or piston 42 so connected with the shaft that movement of the ram in the cylinder rotates the shaft through a limited angle.

By means of a U-shaped mounting bracket 43 on the lower portion of the carrier and trunnions 44 conjoint- 1y carried by that bracket and the carrier, the double acting pneumatic cylinder 41 is mounted with its axis transverse to and intersecting that of the shaft 33 about which the arms 32 swing and is constrained to swinging motion about the axis of said shaft.

The connection between the ram or piston 42 of the cylinder and the shaft 39 comprises an arm 45 that is clamped to a projecting outer end portion of the shaft and has its outer end pivotally connected, as at 46, to the ram or piston. As best seen in FIGURE 2, the swingable mounting of the pneumatic cylinder accommodates the for'eshortenirig of the arm 45 as the latter is angularly displaced by extension and retraction of the piston.

The

ports

47 and 48 of the pneumatic cylinder are connectable with a suitable sour-cc of air pressure 49 through a four-port two-way valve 50 which is arranged to be actuated by the pedal lever 24. When the valve 50 is in its normal position in which it is illustrated in FIGURE 5, it communicates the lower port 47 of the cylinder with the air pressure source and vents the up per port 48 to atmosphere through an exhaust port 51 of the valve; hence the cylinder is maintained in a piston retracted condition which so disposes the carrier as to provide the normal preset close spacing between the backup roll and the shaving cylinder in their machineclosed relationship,

As may be seen from FIGURE 1, full depression of the pedal 19 substantially beyond the point where its lever 24 clears the lifting link 23, brings the pedal lever 24 into actuating engagement with the movable actuating element of the four-port valve 50, reversing the position of the valve from that shown in FIGURE 1. When this happens, the upper port 48 of the cylinder is communicated with the air pressure source 49 while the lower cylinder port 47 is vented to atmosphere through the valve 50 and through a check valve 52 and a throttling valve 53 that are connected in parallel with one another between the valve and the lower port 47 of cylinder 41. Hence if the operator fully depresses the pedal 19 when he wants to cause the carrier to swing from its machineopen to its machine-closed position, he will simultaneously cause the piston 42 of cylinder 41 to be extended, so that when the carrier arrives at its machine-closed position the backup and shaving rolls will be in their compensating relationship, spaced apart by a slightly greater distance than the normal preset amount, and as a result the machine will shave heavy.

The operator, therefore, fully depresses the pedal when he feeds the head and neck portion of the side of leather into the machine so that this area of the piece will be shaved thicker to compensate for the lesser recovery of thickness which characterizes this portion of the side, as compared to the remainder thereof.

It will be observed that since the check valve 52 is ineffective to restrict flow during extension of the piston 42, the throttling valve is bypassed so that the piston moves rapidly and, in any event, rapidly enough to assure completion of the compensating adjustment by the time the actuating cam 14 has swung the carrier to its machineclosed position.

As long as the operator holds the pedal 19 fully depressed, the piston of cylinder 41 will remain fully extended, and the rolls will remain in their compensating relationship just described. However, when the wider and denser body portion of the leather piece approaches the nip of the rolls, there should be a transition from heavy to light shaving, that is the spacing between the rolls should be restored to its normal preset amount, and this should occur gradually. To accomplish such gradual change in the spacing between the rolls, the operator merely releases the pedal which allows the valve 50 to return to its normal position shown in FIGURE 5, and when he does so, the carrier swings at a predetermined slow rate, to translate the backup roll steadily toward the shaving cylinder until the normal preset spacing between the two obtains. This delayed return of the carrier upon pedal release results from the fact that the check valve 52 now prevents flow therethrough, making it necessary for all of the flow to be through the throttling valve 53. The throttling valve is, of course, preferably adjustable.

It will be apparent that the operator can move the carrier directly to its normal machine-closed position in which the'spacing between the backup'roll and the shaving cylinder is at its preset distance if he wishes to do so, by merely partially depressing the pedal so as to avoid actuating the valve 50.

It is desirable to have some means for adjusting the amount of thickness compensation which rotation of the shaft 39 affords, and such adjustment is made possible by permitting the shaft 39 to be adjustingly rotated relative to the arm 45. For this purpose, the end portion of the arm 45 which is clamped to the shaft is bifurcated and provided with a clamping screw 55 which extends transversely through the bifurcations. Loosening the clamping screw allows the shaft to be rotated relative to the arm; tightening it frictionally anchors the arm to the shaft. A concentric dial 56 fixed on the end of shaft 39 opposite the arm 45, can have calibration marks 57 on its periphery that cooperate with an index mark 58 on the lower part of the adjacent arm 32 to provide a visual guide for the making of such adjustments. It will be understood that such adjustments are always made with the piston of the pneumatic cylinder in its normal retracted position.

It will be apparent that any adjustment of the eccentric shaft 39 relative to the radial arm 45 will impose some vertical component of translatory displacement upon the cam follower roller 15, so that the follower roller will in effect walk a small distance along the periphery of the cam 14. To avoid an unpredictable fore-and aft displacement of the carrier in consequence of such walking, the periphery of cam 14 is (as shown in FIGURE 4) made concentric to its axis along the entire arc 59 thereof that would be traversed by the follower roller 15 in the full swing of dial 56, it being understood that said concentric portion of the cam periphery is at the side of the cam which is engaged with the cam follower roller when the cam is in its machine-closed position.

From the foregoing description taken together with the accompanying drawings, it will be apparent that this invention makes it possible to achieve uniformity in thickness or weight throughout the entire area of a side of leather by providing means in a leather shaving machine for compensating for the dilference in the amount the spiral shaving blades stretch the wide and narrow portions of a piece of leather being shaved, and the apparent inability of the narrow head and neck portion of the leather to recover fully from its stretched condition; and that this compensation is accomplished by making it possible for the operator to shave selected portions of the leather heavier than the rest, as the shaving operation proceeds. It will also be seen that this very desirable and important result is achieved by a relatively simple change in the shaving machine and in a manner entirely compatible with an operators established habits and procedure in operating the machine.

What is claimed as my invention is:

1. 'In a leather shaving machine having a power driven shaving cylinder rotatable about a fixed axis, a backup roll to hold a piece of leather against the shaving cylinder, a carrier for the backup roll movable between a machine-closed position in which it holds the backup roll close enough to the shaving cylinder to press a piece of leather thereagainst and a machine-open position permitting a piece of leather to be withdrawn from between the backup roll and the shaving cylinder, manually controllable drive means for effecting movement of the carrier from one to the other of its two positions, and means for setting the position to which the drive means brings the backup roll relative to the shaving cylinder, the improvement which comprises:

(A) power means for eifecting a small defined adjustment of the preset position of the backup roll relative to the shaving cylinder while the carrier is in its machine-closed position; and

(B) manually operable control means for said power means so that an operator may effect adjustment of the spacing between the backup roll and the shaving cylinder as the shaving operation proceeds, and thereby cause the machine to shave light or heavy.

2. The leather shaving machine of claim 1, further characterized by the fact that the manually operable control means also provides the means for actuating the drive means, so that with a single control element the operator may close or open the machine and also vary the spacing between the backup roll and the shaving cylinder.

3. The leather shaving machine of claim 2, wherein said drive means by which the carrier is moved from one position to the other comprises a power driven actuator to produce fore and aft motion between fixed limits, and structure providing a motion-transmitting connection between the actuator and the carrier;

and wherein said power means for effecting the small adjustment of the preset position of the backup roll relative to the shaving cylinder comprises means incorporated in said motion transmitting structure to shift the position of the carrier relative to said actuator.

4. The leather shaving machine of claim 3, wherein said actuator is an eccentric cam rotatable through to open and/or close the machine; and

wherein the means to shift the position of the carrier relative to the actuator comprises a cam follower riding on the eccentric cam, a shaft eccentrically journalled in a portion of the carrier and mounting said cam follower, and

means to oscillate said shaft and thereby move the cam follower relative to the carrier towards or from the eccentric cam.

'5. In a leather shaving machine having a power driven shaving cylinder rotatable about a fixed axis and a backup roll to hold a piece of leather against the shaving cylinder, and a carrier for the backup roll movable between a machine-closed position in which it holds the backup roll close enough to the shaving cylinder to press a piece of leather thereagainst, and a machine-open position per- 9 V mittin-g a piece of leather to be withdrawn from between the backup roll and the shaving cylinder:

(A) drive means for eifectin g movement of the carrier from one to the other of its two positions,

said drive means including a power driven actuator to produce fore and aft motion between the fixed limits and structure providing a motiontransmitting connection between theactuator and the carrier;

('B) a member mo'vably mounted on the carrier for motion between two defined positions and at all times reacting between the actuator and the carrier,

motion of said member in one direction effecting an increase in the spacing between the backup roll and the shaving cylinder to cause the machine to shave heavy, and motion of said member in the opposite direction effecting a reduction in the spacing between the backup roll and the shaving cylinder to cause the machine to shave light;

(C) power means to move said member; and

(D) manually operable control means for said drive means and said power means,

said control means having a single operating member by which an operator may effect closure of the machine and also adjustment of the spacing between thebackup roll and the shaving cylinder as the shaving operation proceeds.

6. 'In a leather shaving machine, the structure of claim 5, wherein the power means for moving said member includes structure to assure rapid mot-ion of said member in the direction to increase the spacing between the backup roll and the shaving cylinder, and slow motion in the direction to reduce the clearance between the backup roll and the shaving cylinder.

7. In a leather working machine having cooperable rotatable work performing and backup rolls, fixed frame structure upon which one of said rolls is rotatab'ly journaled, a movable carrier upon which the other roll is journaled with its axis parallel to that of the first designated roll and which carrier is constrained to motion in opposite directions to translate the roll thereon toward and from the other roll, manually controllable power driven carrier shifting means m'ovable at the will of an operator between defined machine-open and machineclosed positions in the latter of which the rolls are sufiiciently close to one another to grip a piece of leather fed thereto, and means for presetting the spacing of the rolls in their working relationship, the improvement which consists in the provision of means for varying the distance between the rolls when the carrier shifting means is in its machine closed position, and while the machine is acting upon a piece of leather, said last named means comprising:

(A) reversible carrier displacing means connected between the carrier and the carrier shifting means and independent of the presetting means for moving the carrier relative to the carrier shifting means between defined limits that are a small distance apart; and

( B) manually controllable means associated with the carrier displacing means for rendering the latter operative at the will of an operator to displace the carrier from one to the other of its defined limits of motion relative to the carrier shiftingmeans.

8. In a leather working machine having cooperable work performing and backup rolls mounted with their axes parallel for rotation and for relative translatory motion, manually controllable shifting means for effecting relative translation of the rolls at the will of an operator between a machine-open relationship in which the rolls are spaced a substantial distance apart and a machine-closed relationship in which the surfaces of the rolls are in such close juxtaposition that a piece of leather therebetween is forced against the work performing roll by the backup roll, and means for presetting the extent to which the rolls are brought into juxtaposition by the shifting means, the improvement which consists in the provision of means for varying the preset spacing between the rolls while they are in close juxtaposition and a piece of leather is passing between them, said last named means comprising:

(A) means mounting one of said rolls for translatory adjusting motion toward and from the other roll independently of the shifting means and the presetting means and through a small distance;

(B) reversible power means for moving said one roll in opposite directions through said small distance; and t '(C) manual control means operatively associated with said power means to initiate operation thereof and thereby effect adjusting motion of said one roll through said small distance in each direction at the will of an operator.

9. The leather working machine of claim 8, further characterized by the following:

(A) said manual control means is baised to a defined normal position and shiftable therefrom to a defined actuated position in which it causes the reversible power means to hold said one roll in its position at which the rolls are spaced their minimum distance when the machine is closed;

(B) said manual control means is operatively associated with said shifting means to provide for relative translation of the rolls to their machine closed relationship concurrently with motion of said one roll relative to the shifting means in the direction away from the other roll, so that said preset small distance between the rolls is greatest when the machine is first closed and remains so as long as said manual control means is retained in its actuated position; and

(C) means operatively associated with said manual control means and with said power means for effecting motion of said one roll relative to the shifting means in the opposite direction at a predetermined rate when the manual control means is released for return to its normal position, so that at the will of an operator different areas of a piece of leather passing between the rolls can be subjected to differeent degrees of work.

10. In a leather working machine having cooperable work performing and backup rolls mounted for rotation with their axes parallel, and shifting means for translating said rolls relatively toward and from one another between a machine-open relationship in which the rolls are spaced apart by a substantial distance and a machineclosed relationship in which the rolls are in cooperating juxtaposition such that a piece of leather gripped between them is forcefully urged against the work performing roll by the. backup roll:

' (A) means mounting one of said rolls for compensating translatory motion independently of the shifting means in. directions toward and from the other roll between defined limits of compensating motion that are a small distance apart:

(B) a compensating actuator for disposing said one roll at each of its limits of compensating motion;

(C) a manual control element movable consecutively to three defined stations, namely 1) a normal station, (2) a shift station, and (3) a compensating station;

(D) means operatively associated with the manual con trol element and with the shifting means for causing the shifting means to shift the rolls from one to the other of their machine-open and machine-closed relationships whenever said manual control element is moved form its normal station to its shift station;

(E) means operatively associated with the manual control element and with the compensating actuator for causing the latter to dispose said one roll at that limit of its compensating motion at which it is farthest from the other roll when said element is moved to its compensating station; and

(F) means operatively associated with the manual control element and with the compensating actuator for causing the latter to move said one roll at a predetermined rate from its said one limit of compensating motion to its other limit of such motion in consequence of movement of the manual control element out of its compensating station.

11. The leather working machine of claim 10, further characterized by the fact that said manual control element comprises a pedal biased away from its compensating station toward its shift station, and from its shift station toward its normal station, so as to tend to remain in its normal station.

12. In a leather working machine having cooperable rotatable work performing and backup rolls, a frame upon which one of said rolls is journaled, and a movable carrier upon which the other roll is journaled with its axis parallel to that of said one roll and which carrier is constrained to motion on the frame in opposite directions transverse to the axes of said rolls for translating the roll on the carrier toward and from the other roll:

(A) a carrier shifting element movably mounted on the frame and power driven for motion alternately between defined machine-open and machine-closed positions;

(B) manually operable shift control means operatively associated with the carrier shifting element for stopping the same at each of its defined positions;

(C) a follower on the carrier at all times connected with the carrier shifting element to be moved thereby to defined positions corresponding to those of the carrier shifting element;

(D) a shaft mounted on the carrier to turn about its axis;

(B) an eccentric journal portion on the shaft, the follower being mounted on said eccentric journal portion so that by turning the shaft the follower is moved relative to the carrier towards and from the carrier shifting means;

(F) reversible power means to turn said shaft and thus provide for varying the spacing between the rolls when the carrier and the follower are in their machine closed positions; and

(G) manually operable control means for effecting operation of the reversible power means.

13. The leather Working machine of claim 12, further characterized by the fact that said reversible power means rapidly turns the shaft in the direction to increase the spacing between the rolls and turns the shaft at a slower rate in the direction to decrease the distance between the rolls.

14. A leather working machine having cooperable rotatable work performing and backup rolls, a fixed frame upon which one of said rolls is journaled, a movable carrier upon which the other of said rolls is journaled with its axis parallel to that of the first designated roll, and which carrier is constrained to motion on the frame in opposite directions to translate the roll journaled thereon between a machine-open position in which the rolls are spaced a substantial distance apart and a machine-closed position in which the rolls are spaced apart by a small preset distance so that a piece of leather in the nip of the rolls is forced against the work performing roll under pressure, a powered shifting member on the frame movable alternately first to one and then to the other of a pair of opposite positions which correspond to said positions of the carrier, and a manual control member movable between defined normal and shift stations and operatively associated with the shifting member for effecting motion of the latter from one to the other of its defined positions in response to each movement of the manual control member from its normal to its shift station, said leather working machine being characterized by means for compensating for varying the preset distance between the rolls when the machine is closed, said last named means comprising:

(A) a shaft mounted on the carrier for rotation about its axis, said shaft having an eccentric journal portion;

(B) a roller journaled on said eccentric journal portion and confined to engagement with the shifting member to partake of its motion and transmit the same to the carrier and to provide for compensating motion of the carrier through a small distance relative to the shifting member in consequence of rota tion of said shaft;

(C) a reversible actuator reacting between the carrier and the shaft for turning the latter in opposite directions between defined limits of angular motion, at one of which limits the rolls are spaced apart by a slightly larger distance than their preset spacing and in the other of which limits the rolls are at their preset spacing;

(D) means operatively connecting the manual control member with the reversible actuator for causing the reversible actuator to turn the shaft to its first mentioned limit of angular motion when the manual control member is moved to a third defined station; and

(E) means operatively associated with the manual control member and with the reversible actuator for causing the latter to turn the shaft to its said other limit of angular motion at a predetermined rate upon movement of the manual control member away from its said third station.

15. The leather working machine of claim 14, further characterized by the following:

(A) said reversible actuator comprises (1) a reversible fluid pressure motor mounted on the carrier and having an extensible and retractable piston, and

(2) an arm fixed to and projecting substantially radially from the shaft, and having its outer end pivotally connected to the piston;

(B) said means connecting the manual control member with the reversible actuator comprises a valve connected with one side of the fluid pressure motor and by which said side of the motor can be communicated with a source of fluid pressure; and

(C) said means for causing the shaft to turn to its said other limit of motion at a predetermined rate comprises restriction means connected with one side of the motor to constrict flow.

References Cited by the Examiner UNITED STATES PATENTS 1,718,091 6/1929 Traud 6942 2,685,791 8/1954 Hall 69-42 3,041,865 7/1962 Gianoglio 6942 FOREIGN PATENTS 616,038 1/1961 Italy.

JORDAN FRANKLIN, Primary Examiner. FRANK J. COHEN, Examiner.

A. R. GUEST, Assistant Examiner.

Claims

1. IN A LEATHER SHAVING MACHINE HAVING A POWER DRIVEN SHAVING CYLINDER ROTATABLE ABOUT A FIXED AXIS, A BACKUP ROLL TO HOLD A PIECE OF LEATHER AGAINST THE SHAVING CYLINDER, A CARRIER FOR THE BACKUP ROLL MOVABLE BETWEEN A MACHINE-CLOSED POSITION IN WHICH IT HOLDS THE BACKUP ROLL CLOSE ENOUGH TO THE SHAVING CYLINDER TO PRESS A PIECE OF LEATHER THEREAGAINST AND A MACHINE-OPEN POSITION PERMITTING A PIECE OF LEATHER TO BE WITHDRAWN FROM BETWEEN THE BACKUP ROLL AND THE SHAVING CYLINDER, MANUALLY CONTROLLABLE DRIVE MEANS FOR EFFECTING MOVEMENT OF THE CARRIER FROM ONE TO THE OTHER OF ITS TWO POSITIONS, AND MEANS FOR SETTING THE POSITION TO WHICH THE DRIVE MEANS BRINGS THE BACKUP ROLL RELATIVE TO THE SHAVING CYLINDER, THE IMPROVEMENT WHICH COMPRISES: (A) A POWER MEANS FOR EFFECTING A SMALL DEFINED ADJUSTMENT OF THE PRESET POSITION OF THE BACKUP ROLL RELATIVE TO THE SHAVING CYLINDER WHILE THE CARRIER IS IN ITS MACHINE-CLOSED POSITION; AND (B) MANUALLY OPERABLE CONTROL MEANS FOR SAID POWER MEANS SO THAT AN OPERATOR MAY EFFECT ADJUSTMENT OF THE SPACING BETWEEN THE BACKUP ROLL AND THE SHAVING CYLINDER AS THE SHAVING OPERATION PROCEEDS, AND THEREBY CAUSE THE MACHINE TO SHAVE LIGHT OR HEAVY.