US 3547432 A
Description (OCR text may contain errors)
United States Patent  Filed June 17, 1968 [4S] Patented Dec. 15, 1970  Assignee USM Corporation Flemington, NJ.
a corporation of New Jersey  SHEET HANDLlNG DEVICES 4 Claims, 5 Drawing Figs.
 U.S. Cl 271/20, 271/19, 271/25  Int. Cl B65h 3/08, B65h 3/22, B65h 3/30  Field ofSearch 271/1l,5, 19, 20, 24, 25, 26, 30, 31
 References Cited UNlTED STATES PATENTS 326,124 9/1885 Kneeland 27l/20 2,003,698 6/1935 Remington 271/25 871,498 11/1907 Graham 271/20 754,204 3/1904 Dexter 271/20 1,110,704 9/1914 Minnick. 271/20 2,554,320 5/1951 Battey 271/20 Primary Examiner-Richard E. Aegerter Assistant Examiner- Roger S. Gaither Attorneys-W. Bigelow Hall, Richard A. Wise and Aubrey C.
Brine ABSTRACT: A machine for feeding a preselected number of flexible sheets of material from a stack of sheets which includes a device for effecting release from the stack of only the selected number of sheets to be fed. The device has an element which engages the face sheet of the stack and moves it in a direction toward a point on the stack where pressure is applied by another element of the device. The operation is performed on each successive underlying sheet that is desired to be fed, forming a buckle in each of the sheets and thereby separating it from its underlying sheets, after which the remainder of the stack is clamped and the preselected number of sheets are fed from the stack.
PATENTED DEC] 5 i976 SHEET 2 OF 3 SHEET HANDUNG DEVICES BACKGROUND OF THE INVENTION The present invention relates to a machine for feeding flexible sheets from a stack and in particular to a device for effecting release of a preselected number of sheets to be fed from the stack.
One of the problems which has existed in the past in the sheet-feeding art has been that of reliably feeding only a Single sheet of material from a cut stack of sheets, The problem has prevailed for many years, particularly in the garment industry, where much of the fabric feeding from a stack has heretofore been done by hand labor.
Various devices have been developed to accomplish this task, for example those described in US. Pat. Ser. No. 647, 784, filed June 21, 1967 in the name of Richard R. Walton, and U.S. application Ser. No. 668,574, now U.S. Pat. No. 3,430,949 filed Sept. l8, 1967 in the names ofDonald F. Herdeg and Paul E. Morgan, now U.S. Pat, No. 3,430,949 both as signed to the assignee of the present invention. These devices have proved successful in the handling of a great variety of materials by providing automatic machinery which is both efficient and reliable in feeding a single sheet from a stack and stacking it at a selected location.
However, a second and perhaps moredifficult problem exists when it becomes desirable to feed a preselected number of sheets in registry from a stack. Such a situation quite often exists in the field of apparel manufacturewhere the next operation after unstacking the sheets is that of seaming, bonding, stitching or otherwise operating on the sheets while in the mated condition. Here, as in the operation where a single sheet is to be fed from the stack, it is of the utmost importance that only the preselected number of sheets be presented to the work station such that unnecessary cost of rejecting the finished product be eliminated. A machine constructed for the aforementioned purpose, therefore, must be simple and reliaole in operation such that only the preselected number of sheets of material are fed from the stack to the subsequent work station. The machine must further be capable of operating on a great many different kinds of materials wherein the single sheets themselves may vary over a wide range of thickness, degree of porosity and flexibility, or where there is a frictional variation among the sheets of the stack.
ln presently existing machines, one of the basic problems is that of separating the preselected number of sheets from the stack, so that they may be cleanly removed from the underlying sheets. Thus, when it is desired to remove one, two, three, etc. sheets fromthe face of the stack in registry by a single pickoff operation, the operator should have the ability by simple adjustment to separate the preselected number of sheets such that they may be removed cleanly from the stack of material.
The present invention therefore has as an object to provide a machine for feeding a preselected number of sheets of material from a stack, the machine being both effective and reliable to feed single or multiple sheets having a wide range of material characteristics and thickness;
Another object of the invention is to provide a machine for feeding sheets of material from a stack, the machine having a device which is capable of separating only the selected number of sheets to be fed from the stack.
A further object of the invention is to provide a sheetseparating device to be employed in a sheet feeder which device is simple in construction and readily adjustable to separate only a preselected number of sheets from a stack thereof.
SUMMARY OF THE INVENTION These objects of the invention, and other objects which will become apparent as the description proceeds, are achieved by providing a machine for feeding flexible sheets of material, such as fabric, from a stack wherein a pickoff means is employed for engaging the face of the stack and removing a plurality of sheets, or a single sheet, as is desired to be fed from the stack.
A device for separating the sheets is provided in the machine which comprises a means for engaging the surface of the face sheet of the stack and means for moving the surfaceengaging means in a direction having a component substan tially parallel to the face of the stack to slide the engaged sheet over the underlying sheets in the stack. A plurality of the sur face-engaging means are employed, and operated in sequence, when it is desired to feed more than one sheet from the stack. When the selected number of sheets have been separated by the surface-engaging means, means for applying a clamping pressure to the underlying sheets of the stack is applied in the area where the sheet or sheets have been removed from the underlying sheets, to thus retain the stack while the pickoff means is operated to remove the sheet, or sheets, from the stack.
Generally a pressure-applying means is disposed in the direction of movement of the surfacc-engaging means, and is effective when applied to the face of the stack to produce a buckle in the sheet of material being moved by the surface-engaging means. The forming of the buckle thus releases the sheet being operated on from the underlying sheet by providing a lack of frictional engagement with the undcrlyingshcet, over the buckled area. Those sheets having such lack of drug are then cleanly removed by the sheet p'ckoff means without disturbing the underlying sheets which are held together by a clamping means applied to the underlying sheets of the stack and by frictional engagement.
The sheet or sheets so separated from the stock remain in alignment during separation, but for the separator locations, and it is therefore possible to retain alignment of the sheets during the separation and pickoff process, if desired.
The pressure-applying means of the device is considered to establish a short length of column in a sheet from its point of application to the place where the surface-engaging means contacts the sheet. The area of contact between the face sheet and the underlying sheet is generally small relative to. the total area of the sheet, thus, very little pressure need be applied to the surface-engaging means to break the frictional lock over this area. As the engaging means scuffs the sheet portion towards the pressure-applying means, the column thus formed in the face sheet experiences a buckling, forming an S-curve of bending, or buckle, in the sheet. Theunderlying ply, if still being carried by frictional attachment (fiber entanglement or surface roughness) to the face sheet, resists such buckling, as only a negligible force is being applied to this sheet in the direction of the pressure-applying means. The resistance to buckling of the underlying sheet causedby the column effect together with the buckling of the face sheet thus overcomes any frictional lock between the two sheets and the underlying sheet falls back to its flat condition, where it is clamped with the remainder of the stack.
In general, the separating devices are employed in pairs, each being provided at a corner of the stack of sheets rearwardly of the pickoff means. The devices are generally so ar ranged that the surface-engaging means in their operation to release a sheet from the stack are moved with a component toward one another, or diagonally from the corners toward the center of the stack face.
BRIEF DESCRIPTION OF THE DRAWlNGS FIG. I is an elevational view showing an illustrative machine embodying the invention for feeding sheets of material such as fabric or the like, in which the present invention is embodied;
H6. 2 is atop plan view taken along the line ll-ll of H6. 1, and showing details of the invention taken on an enlarged scale for clarity;
FIG. 3 is a side elevational view, partly in section, taken along the lines Ill-Iii of FIG. 2 and showing details of the separating device as depicted in FIG. 2;
- FIG. 4 is a side elevational view similar to that of FIG. 3 but showing the various elements of the device at another point in time during its operation; and
FIG. 5 is a side elevational view similar to FIGS. 3 and 4 but showing the various elements of the device taken at yet another point in time during machine operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT While it is considered that the principles of the invention are broadly applicable to machines for feeding flexible sheet vlr'naterial from a stack, the invention has been herein illustrated in a machine for feeding sheets of fabric material, and will be so described.
f Referring to the drawings, and in particular FIG. 1, there is shown a machine for feeding flexible sheet material such as -"fabric, which has been constructed in accordance with the teachings of the present invention and which includes a frame I0 having an elevator 12 mounted thereon for movement in the vertical direction. Adjacent the upper portion of the frame while the lower sprocket 30 is driven in'bo th the clockwise and counterclockwise direction by suitable motor means (not shown).
The elevator 12 further comprises a substantially horizontal surface 32 on which a pallet -34 bearing a stack S of flexible pieces of material such as fabric may be located.
7 With the structure thus far described it will be observed that movement of the sprocket 30 in counterclockwise direction as viewed in FIG. 1 is effective to cause the elevator 12 to move upwardly along the track 22, while clockwise directional movement of the sprocket 30 is effective to cause the elevator 12 to move downwardly.
= The carrier arm 14 comprises housing'38 having a lug 40 provided at one end thereof. The lug 40'has a cylinder 42 pivotally connected to it which cylinder extends forwardly along the length of the arm 14. The cylinder 42 is of the double action-type which may be operated by a suitable source of fluid pressure (not shown). A carriage support rod 44 is affixed to the housing 38 at a point forward of the lug 40, and extends longitudinally along the greater portion ofthe arm 14. Referring still to FIG. 1, it will be observed that the work head comprises a carrier member 46 attached to a housing 48 which is slidably mounted on the rod 44. The sliding housing 48 and the carrier member 46 provide a carriage assembly for the various elements of the sheet pickoff device and movable along the rod 44 over a lengthwise portion of the carrier arm I4. The cylinder 42 is provided with a piston rod 50 pivotally attached to the forward end of the housing 48 to connect the cylinder 42 to the carriage assembly.
I The carrier member 46 is shown to be provided with a downwardly extending portion to which a horizontally extending mounting plate 54 is attached. The plate 54 is generally provided with a plurality of slotted openings through which threaded fasteners 57 extend to support a plurality of tubular members 58.
The carrier arm 14 is provided with a pair of limit switches LSI and LS2 affixed at the extreme ends of the arm. The housing 48 is in turn provided with an outwardly extending flange 60 having an upper surface aligned for contact with the act'ivating rollers of the switches LS1 and LS2. These switches LS1 and LS2 are operatively connected in a control circuit which is effective to energize the various air valves and motors which operate the cylinder 42, the elevator 12 and which provides fluid for the pickoff means employed in the machine.
Additionally, the switches LS1 and LS2 may be used in conjunction with a suitable circuitry to initiate operation of, and time delay sequences in the novel-separating device which will be described in greater detail as the description proceeds.
The device thus far described, is similar in detail and in operation to that described in US. application Ser. No. 668,574, filed Sept. 18, I967 in the name of Herdeg et al., which application has previously been alluded to. As in the above-mentioned application, the present device is generally provided with a pickoff means for removing the face sheet, or preselected number of sheets from the stack and delivering the sheet or sheets to the desired location. The pickoff means generally designated by the numeral 62 may be of the type described in detail in US. allowed Pat. application Ser. No. 647,784, tiled June 2l, 1967 in the name of Richard R. Walton. However, the device may be modified in accordance with the aforementioned I-Ierdeg application, or may be of the type more recently described in copending US. application Ser. No. 737,580, filed June 17, I968 in the name of Mason et al. As each of the aforementioned pickoff means is considered to be adequately described in the reference patent application. it is herein sufficient to state that the choice of any one of these, or other pickoff devices, may be made to meet the particular requirements of the application with regard to material to be handled as well as the number of sheets to be removed, and the precision required in stacking or mating at the location of deposit of the sheets or sheet.
Referring now to FIGS. 2 and 3 taken in connection with FIG. 1, it will be observed that a T-shaped support member 64 is attached to the frame 10 above the elevator 12; At each end of the cross portion of the T-shaped member 64 there is provided a sheet-separating device 66 comprising a mounting plate 68 which is disposed on the member 64. A pair of slotted openings 70 are provided in the plate 68, and a pair of fasteners 72' are received therethrough 'to connect the device 66 to the member 64 in-a manner providing for lateral adjustment of the device along the cross portion of the T-shapcd member.
Each of the devices 66 are identical in structure and in operation, and therefore only one such device will be described, like elements ofeach device being given like reference numerals as the description proceeds.
Support means for the various movable elements of the device 66 is further provided by a pair of pivot blocks 73, 75 and a centrally located pivot block 74 whichare each fixedly mounted on the plate 68. The pivot block 74 has an opening therein for receiving a pin 78 and pair of pneumatic cylinders 80 and 82 of the double-action type in turn each receive the pin 78 in pivotal engagement. Each of the cylinders 80 and 82 are further provided with a pivotal connection to a pair of pins 84 and 86 respectively which are received in the blocks 73 and 75. The cylinder 82 is thereby pivotally attached between the blocks 74 and 73, while the cylinder 80 is independently, pivotally supported between the blocks 74 and 75.
The cylinder 82, as best shown in FIG. 2, is provided with an angle member 88 connected to a piston rod 90 activated by fluid pressure in the cylinder. A guide pin 92 is received in a flanged portion of the cylinder 82 for slidable movement, and
t has one end connected to the angle member 88 to thus add rigidity to the member and prevent rotational movement thereof during operation ofthe device.
Likewise, the cylinder 80 has a piston rod 94 connected to an angle member 96 which is connected to a slidable guide pin 98, all of which are designed to operate similar to the elements described in connection with the cylinder 82.
Referring now to FIGS. 3 through 5, taken in connection with FIG. 2, it will be observed that the angle members 96 and 88 comprise a downwardly extending tab portion terminating adjacent the face of the stack S. The tab portion of the members 88 and 96 are each provided with a means for engaging the face surface of the stack S, in the form of strips of card cloth 100 and 102. The card cloth elements [00 and 102 are oriented such that their points are directed toward the pickoff elements 62 thereby providing pushing action to the engaged sheet when moved in that direction.
While the unidirectional frictional quality of the card cloth elements 100 and 102 lend that material particularly useful in this application, it should herein be brought out that the ele ments S8 and 96 might also be provided with a plurality of sharp pins having their ends oriented toward the pickoff member 62, or a sticky tape material, etc., each of which may be desirable for a particular application.-
lt has further been found that in many applications where the specific device 66 is to be employed with sheets having a wide range of thickness, the use of sharp pins which are readily interchangeable or are adjustable in length, is highly desirablc.
In addition to pivotally attaching the cylinders 80 and 82 to the blocks 73 and 75 the pins 84 and 86 serve to pivotally attach a pair of substantially parallel arms 104 and 106 to the separating device 66. The arms 104 and 106 extend over the stack 5 and are independently movabiewith respect to the cylinders 80 and 82, and to each other. As'best shown in FIG. 3, the arm 104 is provided with an angle bracket 108, having one flange provided with a pair of slotted openings through which a pair of fasteners are received to adjustably attach the bracket to the arm 104. The lowermost flange of the bracket 108 has an opening provided therein through which the threaded portion of a presser foot 110 is received. A nut is disposed on either side of the lowermost flange of the bracket 103, in engagement with the threaded portion of the foot 110, to hold the foot lockingly engaged on, but adjustable with respect to, the flange.
As in the case with the arm 104, the opposite arm 106 is likewise provided with an angle bracket 112 having a lower flange provided with a presser foot 114 which depends downwardly from the arm. Each of the presser feet 110, 114 when so disposed for pivotal movement is effective to contact the face of the stack 5 and provide means for applying pressure thereto.
in viewing the construction shown in FIGS. 3, 4 and 5 it will be noted that a clamping means is provided in the separating device 66 in the form of a vertically disposed cylinder 116 having a portion threadedly received in an opening in the mounting plate 68 and held in place by a lock nut. The cylinder 116 has a piston rod 118 which serves to support, and is received through an opening in, a clamping plate 120. The plate 120 is adjustable along the length of the rod 118 and is held in place by a pair of lock nuts threadedly engaged on the piston rod. As is evident from viewing FIGS. 3 and 4, the vertical cylinder 116 is attached to the mounting plate 68 in a posi tion whereby the clamping plate 120 is disposed above the stack S with the piston rod 118 in its retracted position, but is moved to a position clamping the stack S when the piston rod is in the extended position. A slotted opening 122 is provided in the plate 120 for receiving the angle members 88 and 96 in their retracted position, thereby allowing both clamping and sliding of the material to be executed at substantially the same position on the face of the stack.
A pair of adjustable stops 124 and 126 are disposed beneath the cylinders 80 and 82 respectively to retain the orientation between the fabric-engaging means connected with each cylinder, and the face of the stack S, when the stack is removed from under the separating device 66 by the elevator 12.
To accomplish the aforementioned separation, the sheetseparating device 66 is employed as best shown in FIGS. 3, 4 and 5. Although the devices 66 as shown in these FIGS. are operative to effect separation of two sheets from the stack, to be picked off in registry by the device 62 it should here be mentioned that by closing off the fluid power to one of the cylinders 80 or 82, the device is effective to separate only one sheet from the stack S. It should further be evident that a third such cylinder and related structure might be added to the construction which would operate in like sequential manner to provide for separation of three-sheets from the stack. Also, by
providing suitable means for retaining the buckled sheet in its buckled state, such as a movable finger element depending from above the stack (not shown) it would be only necessary to repeat operation of the cylinders or 82 to buckle a plurality ofsheets, as desired.
Referring to FIG, 2 with the elevator 12 in its upper position the separating device 66 is supported over the stack S with the lower extremities of the members 88 and 96, and hence the card cloth and 102, contacting the face of the stack. The cylinders 80 and 82 are pressurized on one side so that the piston rods 90 and 96 are in their retracted positions. Each of the presser feet and 114 are in contact with the face of the stack, one being located on either side of the line of movement of the members 88 and 96.
As with the cylinders 80 and 82, the cylinder 116 is pressurized so that the piston rod 118 is in the retracted position, thus locating the clamping plate in spaced relation with the face of the stack S. The machine is now in position to feed a pair of sheets from the face of the stack.
Referring now to FIG. 3, the opposite end ofthc cylinder 80 has been pressurized so that the member 96 is caused to slide over the face of the stack. The card cloth 102 contacting the face sheet becomes engaged therewith, and causes the sheet to move over the underlying sheets forming a buckle between the member 96 and the presser foot 114. With the elements so an ranged, the member 88 now rests on the secondmost face sheet of the stack, the face sheet having easily slid from under the card cloth 100 when moved in the direction of the engaging points of the card cloth. The clamping plate 120 is still maintained above the stack S, the onlycylinder actuated being that connected to the member 96. 1
Referring to FIG. 4, the cylinder 32 has now been actuated such that the member 88 is moved forwardly towards the presser feet 110, 114 so that a buckle forms in the now face sheet of the stack S between the member 88 and the presser feet 110, 114, directly behind the member 96. The cylinder 116 is now actuated so that the clamping plate 120 is forced downwardly upon the stack S to clamp the third sheet and underlying sheets in place while the pickoffmembcr 62 is moved away from the separating devices 66 carrying, with it the two face sheets which have been separated from the stack S.
Additionally, the elevator 12 may be lowered during operation of the pickoff device 62 to facilitate removal of the separated sheets from the stack, the elevator then being reciprocated to substantially its initial position to start a new cycle. The elevator 12 when returned upwardly is generally positioned so that the top of the stack is always substantially at the same position relative to the device 66. The plate 120 is also positioned in the device 66 such that it maintains its effectiveness over the initial portion of elevator downward travel.
While the operation has been described with regard to one device 66, it should be understood that each of the cylinders 82, 80 and 116 are connected to a common source of fluid pressure such that operation of the devices to separate the stack is sequentially synchronized.
Although the specific circuitry involved in pressurizing the cylinders 80, 82 and 116 in sequence has not been described in detail, it is considered that various workable arrangements employing both electrical and pneumatic components could be evolved by one skilled in the art, andtherefore, will not be herein described in detail.
The machine as herein described comprises two-separating devices 66. However, it should be evident that applications may exist where a single device 66 could be employed, or wherein more than two such devices would be necessary to adequately separate the material.
However, it has been found that for most applications in the garment trade, wherein average size sheets of fabric material are fed, the two devices 66 are sufficient to adequately control separation and movement of the material from the stack S.
Also, it might be mentioned, that having two separator devices 66 acting on the stack 5 give the redundency or failsafe condition wherein only when both units incorrectly separate does a malfunction exist in the feeding process.
Additionally, it should herein be brought out that the location of the devices 66 at the corners of the stack has proved advantageous in the greater number of fabric shapes involved in the garment trade. While the invention herein described is not considered to be limited to use of the separating devices 66 at the corners of the stacks, such arrangement has proved advantageous in most stacks having such corners available.
- It has also been found that for very stiff materials the presser feet'll4 and 110 may be swung back out of use whereby the buckles created by the members 88 and 96 become much larger,.the material being forced against the pick up 62 rather than the presser feet. r
' The various features and advantages of the invention are thought to be clear from the foregoing description. Various other features and advantages not specifically enumerated will undoubtedly occur to those versed in the art, as likewise will many variations and modifications of the preferred embodiment illustrated, all of which may be achieved without departing from the spirit and scope of the invention asdefined by the following claims.
1. A machine for feeding flexible sheets from a stack thereof comprising:
pickoff means for engaging the ing the sheets therefrom;
and mechanism for separating a preselected number of sheets from the stack, said mechanism having a plurality of means disposed adjacent the stack for engaging the surface of the face sheet of the stack and movable in a common direction;
said separating mechanism further including a pair of presser feetdisposed one on either side of the path of travel of each of said surface-engaging means for applying pressure to the face of the stack at a location spaced from each of the surface-engaging'means in the direction of movement of said surface-engaging means whereby a face of the stack and removbuckle is formed in each of the engaged sheets between the respective engaging means and said presser feet during movement of the respective engaging means;
means for moving said surface-engaging means in a direction having a component substantially parallel to the face of the stack to slide the face sheet over the underlying sheets to separate the face sheet therefrom; other means disposed adjacent to the stack for engaging the surface of the now face sheet in the area where the face sheet is moved off the stack; v
means for moving said other means in a direction having a 4 component substantially parallel to the face of the stack to slide the engaged'now face sheet over its underlying sheets to cause separation of the sheet therefrom; and
means for applying a clamping pressure to the underlying sheets of the stack in the area where the now face sheet is moved from over the underlying sheets.
2. A machine in accordance with claim 1 wherein said separating mechanism further includes support means disposed above the stack and wherein said presser feet and said respective surface-engaging means are each pivotally connected to said support means for independent movement toward and away from the stack face.
3. A machine in accordance with claim 1 which comprises at least a pair of said separating mechanisms, said mechanisms being disposed at opposite sides of said pickoff means and rearwardly thereof with respect to the sheet pickoff movement ofsaid means.
4. A machine in accordance with claim 3 wherein said separating mechanisms are located adjacent opposite corners of the stack and said surface-engaging means'of one separat ing mechanism is disposed for movement with a component towards each surface-engaging means of the other device in sliding an engaged sheet over the underlying'sheets.