US3550932A - Adjustable pick-off devices - Google Patents

Description

United States Patent [72] Inventors Ronald C. Mason Hamilton; George F. C. Burke, Beverly; George A. Fuller, Jr., Wenham, Mass. [21] Appl. No. 737,580 [22] Filed June 17, 1968 [45 Patented Dec. 29, 1970 [73] Assignee USM Corporation Flemington, NJ. a corporation of New Jersey [54] ADJUSTABLE PICK-OFF DEVICES 8 Claims, 5 Drawing Figs.

[52] US. Cl 271/26 [51] Int. Cl B65h 3/08 [50] Field ofSearch 271/26, 18,

[56] References Cited UNITED STATES PATENTS 2,878,016 3/1959 Russell et a1 271/11 3,176,979 4/1965 Enge1mann.... 271/18 3,386,396 6/1968 Jacobs et a1. 271/26 Primary Examiner-Richard E. Aegerter Assistant Examiner-Roger S. Gaither Attorneys-W. Bigelow Hall, Richard A. Wise and Aubrey C.

Brine ABSTRACT: A device for transferring; a preselected number of sheets of material from a stack of sheets and depositing the sheet, 01' sheets at a selected location. The device comprises a pickoff head which is adjustable to accommodate the difference in thickness between sheets of material to be fed, and which adjustment may be made to reliably pick off one, two, or more sheets of material in registration, as desired.

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[IN/PIE mm George FC Bur/re Georye-A.Fuller Jr Forzald CZMczson ADJUSTABLE PICK-OFF DEVICES BACKGROUND OF THE INVENTION This invention relates to a device for feeding flexible sheet material .and in particular to, apparatus for removing a preselected number of flexible sheets from a stack, or work support and depositing the sheet, or sheets at a selected location.

Heretofore, there have been developed a number of devices which were devised to solve the problemof feeding flexible work sheets from a stack, which devices have met with varying degrees of success. In the fabric industry, in particular, reliably feeding a single sheet of woven, knit or otherwise porous material from a stack of such materials is a task which is prevalent in a number of operations, and which has for many years been performed by hand. I

Devices which have been successful in accomplishing this task, have been described in application Ser. No. 647,784, filed Jun. 21, 1967 in the name of Richard R. Walton, and application Ser. No. 668,574, filed Sept. 18,1967, now U.S. Pat. No. 3,430,949, in the names of Donald F. Herdeg and Paul E.

Morgan, both assigned tothe assignee of the present invention. These devices have proved successful in solving the problem of single sheet feeding, by providing automatic machinery which is both efficient and reliable in feeding a single sheet from a stack.

However, another problem which presents itself to the fabric manufacturer, is that of feeding a predetermined number of sheets, say one, two, three or more from a stack to a location in which the next operation is to be performed on the sheets, one underlying the other in registration. Here, as in the operation wherein a single sheet is to be fed, it is of the utmost importance that only the selected, number of sheets be presented to the work station whereinthe stitching, bonding or other operation is to be performed. In dealing with this problem, therefore, it is desirable that the device devised for this purpose be simple and reliable in its adjustment, such that only the preselected number of sheets of material, are fed from a stack. The problem is somewhat complicated when the machine is to be used with a great many different materials, and where the single sheets themselves may vary over a wide range of thickness.

The present invention, therefore, has as an object to provide a device for transferring a preselected number of flexible sheets from a stack, which device is adjustable for reliably and efficiently removing the proper number of sheets, over a wide variety of materials and sheet thicknesses.

The invention has as a further object to facilitate removal of a preselected number of flexible sheets from a stack and to release the sheets at a selected location.

Another object of the invention is to provide a device for transferring fabric sheets from a stack to a selected location which is efficient and reliable yet simple in operation.

SUMMARY OF THE INVENTION The above objects are achieved by providing a device for transferring a preselected number of sheets from a stack thereof in which pneumatic means, and pointed gripping means, are provided in combination, with the gripping means being presented to the stack face in a manner to grip only the desired number of sheets and transfer them to the selected location. 1

Generally, the device comprises a conduit having an opening which is positioned adjacent the face of a stack of sheets and which is further connected to a vacuum creating means, which may be a vacuum source of any known design. A means adjustably movable with respect to the gripping means is provided for limiting the extent of the pointed gripping means which is to be presented to the stack of sheets.

When it is desired to transfer pieces of thin material from the stack to a selected location, an adjustment may be made to the device to present and expose only a small portion of the pointed means to the stack of material to remove one sheet, and a similar further adjustment made to the device to present and effectively expose a greater portion of the pointed gripping means to the stack to remove two sheets, three sheets, etc.

When a .thicker material is encountered, the adjustment previously made 'for the thin sheets will in most cases be unsatisfactory to pick up the same number of sheets of thicker material. However, employing the teachings of the present invention, a simple change of setting of the device, will effectively present a greater or less, extent of the pointed gripping means to the stack, thereby providing for transfer of the preselected number of sheets of the new material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view showing an illustrative fabric handling machine having the present invention employed therein;

FIG. 2 is a sectional elevational view showing a portion of the machine shown in FIG. 1 taken on an enlarged scale for clarity, and including a sheet transferring device;

FIG. 3 is a sectional elevational view of the device shown in FIG. 2 taken at right angles to the view shown in FIG. 2 and showing the various elements of the device in a different position during operation of the fabric handling machine;

FIG. 4 is a fragmentary bottom plan view of the device of FIGS. 2 and 3 showing details of the construction; and

FIG. 5 is an elevational view showing a portion of the structure of FIG. 2, taken on a greatly enlarged scale, and showing the various adjusted positions of the device of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT 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 10 having an elevator 12 mounted thereon for movement in the vertical direction. Adjacent the upper portion of the frame 10 there is fixedly mounted a carrier arm 14 extending above the elevator 12, which arm has a work head 16 slidably mounted thereon. v

The elevator 12 is provided with a pair of rollers 18 and 20 disposed on opposite sides of the vertical track 22 affixed to the frame 10. The elevator 12 is further connected by a clamping member 24 to an endless chain 26, which is engaged with sprocket members 28 and 30. The uppermost sprocket member 28 is free running and serves as an idler sprocket while the lower sprocket 30 is driven in both 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 fabric or other material may be located.

With the structure thus far described, it will be observed that movement of the sprocket 30 in the 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 a housing 38 having a lug 40 provided at one end thereof. The lug 40 has a cylinder 42 pivotally connected to it which 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 lengthwise along the greater portion of the arm 14 Referring still to FIG. 1, it will be noted that the work head 16 comprises a carrier member 46 which is attached to a housing 48 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 are movable along the rod 44 over a lengthwise portion of the carrier arm 14. The cylinder 42 is provided with a piston rod 50 pivotally attached to the forward end of the housing 48 thereby connecting the cylinder 42 to the carriage assembly.

The carrier member 46 is 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 only one of which is shown.

The carrier arm 14 is provided with a pair of limit switches LS1 and LS2 affixed at the extreme ends thereof. The housing 48 is provided with an outwardly extending flange 60 having an upper surface aligned for contact with the activating rollers of the switches LS1 and LS2, and these switches are operatively connected in an electric or pneumatic circuit which is effec- ,tive to energize the various air valves and motors which operate the cylinder 42, the elevator 12, and provides fluid flow to the pickoff means which is to be described in greater detail as the description proceeds.

The device as thus far described, is similar in detail and in operation to that of application Ser. No. 668,574, filed Sept. 18, 1967, now US. Pat. No. 3,430,949, in the name of Donald F. l-lerdeg and Paul E. Morgan, which application has previously been alluded to herein. As in the above-mentioned application, the present device is generally provided with a means for aiding in separation of the face sheets on the stack S. T-he separating means designated by the numeral 62 may take the form of the vacuum holdback device which is described in detail patent application Ser. No. 647,784, filed Jun. 21', I967 in the name of Richard R. Walton, or may be of any other suitable type. As either of these separating means is considered to be adequately described in each of the aforementioned applications, it is herein sufficient to state that the separating means 62 when disposed adjacent the stack S is effective to cause separation of the face sheets of the stack S and thereby facilitate removal of the sheets by the pickoff device.

Referring now to FIG. 1 taken in connection with FIGS. 2, 3 and 4, it will be noted that each of the tubular members 58 has a pickoff element 64 disposed at one end. The pickoff element 64 comprises a hollow casing 66 having a boss or right angle portion 68 which is connected to the tubular member 58. The tubular member 58 is connected to a vacuum creating means (such as a standard vacuum source) and the hollow casing 66 thereby becomes a conduit for flow when the vacuum is applied to the tubular member. A pin 70 is received through a pair of opposed openings in the walls of the casing 66, and a slidable tubular element 72 is disposed in the casing 66, having the pin 70 received through a pair of elongated openings 74 and 76 provided in the element wall. Thus, both the hollow casing 66 and the slidable tubular element 72 combine to form an extendable conduit as is best shown in FIG. 3.

Referring still to FIGS. 2, 3 and 4, it will be observed that adjacent the lower end of the element 72 there is formed an outwardly extending flange 78. A threaded element in the form of a nut 80 having an inwardly flanged portion 82 and a threaded portion 84 is rotatably mounted adjacent the lower end of the tubular element 72. The lower end of the conduit is substantially covered by a shroud 86 having a downwardly facing planar surface 88, and external threads matingly engaged with the threaded portion 84 of the nut 80. A resilient biasing means in the form of a washer 90 is located between the shroud 86 and the flange 78, such that movement of the nut 80 and the shroud 86 relative to one another causes compression of, or releases compression in, the washer 90 thereby maintaining the shroud in the adjusted position relative to the tubular element 72. The washer 90 is of a chosen thickness and material having, for instance, a durometcr which allows approximately 0.015 to 0.025-inch axial adjustment of the shroud 86 relative to the element 72.

Adjacent the lower end of the tubular element 72 there is further provided a pointed means 92 having a rigid holder or a base portion 94 and a row of pointed elements in the form ofa removably mounted strip of card cloth" 96. It should be recognized at this point in the description that although the pointed means 92 is shown to comprise card cloth material, a plurality of needles having their points uniformly angularly oriented for unidirectional frictional contact may be substituted in the base portion 94 for the card cloth 96in certain applications. the base 94 of the pointed means 92 has its ends received in and secured as by welding to thewallsof diametrically aligned slots 98 provided in the lower end of the tubular element 72, and also has its ends slidably received within a pair of diametric, cooperative grooves 100 formed in the shroud86.

Thus, the base 94 of the pointed means92 serves as 'a key in the slots 98, 100 to prevent rotational movement between the shroud 86 and the tubular element 72 when the nut 80' is rotatedrelative thereto. Accordingly, it will be understood that angular adjustment of the nut 80 with respect to 'the shroud 86, which is held nonrotational relative to the clamped element 72 by means of the portion 94, causes the shroud and its surface 88 to expose more or less of the teeth for penetrating the stack S, depending on the direction of rotation. A centrally disposed slot 102 is provided in the surface 88 of the shroud 86 for receiving and exposing the teeth of the card cloth 96, and a pair of slotted openings 104 and 106 disposed on opposite sides of the card cloth provide for flow of air into the conduit.

Referring still to FIGS. 2, 3 and 4, a sheet stripper member 108 having a piston 110 located at one end thereof and a pair of spaced parallel legs 112 and 114 extending downwardly from the conduit is disposed for axially slidable movement in the casing 66. A coil spring 116 is provided between the pin 70 and the piston 110 to bias the stripper member 108 upwardly in the casing 66, and the legs 11 2 and 114 are in straddled relation with the pin 70 to limit downward movement of the member 108, as best shown in FIG. 3.

It will be further noted from FIG. 3, that the legs 112 and 114 are so spaced that in their downwardmost position they respectively extend through the slotted openings 104 and 106. In addition, the piston 110 is effective to block the boss or right angle portion 68 of the conduit to close off air flow through the conduit when positioned as shown in FIG. 3.

An opening 116 is formed in the casing 66 through which a pipe 118 is provided, extending into an opening 120 in the piston 110. The pipe 118 is close fitting in the opening 120 and provides a source of fluid pressure to operate the piston 110. When pressure is introduced into the pipe 118, therefore, the stripper member 108 assumes the position as shown in FIG. 3, while with the pressure released the spring urges the member 108 to the inoperative position shown in FIG. 2.

With the arrangement as described, only a small quantity of air or other fluid is employed in moving the stripper member 108.

In its typical mode of operation, therefore, the pickoff element 64 is moved from the stack S to a selected location where the sheet, or sheets are to be deposited, with a source of vacuum connected to the tubular members 58 and a source of pressure connected to the line 118, each of which are connected to a suitable operating circuit as heretofore alluded to. With the elevator 12 in its upward position, the tubular element 72 extends downwardly such that the surface 88 contacts the face of the stack S. A vacuum is drawn in the conduit which acts through the slotted openings 104 and 106 to draw the face sheet or sheets upwardly onto the card cloth 96. The sheet or sheets contacting the surface 88 effects a closing off of the slotted openings 104 and causing the tubular element 72 to move upwardly with the pointed means 92 due to the vacuum in the conduit 66, and the sheet, or pair of sheets as shown in FIG. 2, are drawn from the face ofthe stack.

A characteristic of the card cloth 96 is the arrangement of the points for unidirectional pickoff of the material. Thus, in viewing FIG. 2, after pickoff of the material, subsequent movement of the pickoff element 64 would be from left to right to take advantage of the holding effect of the card cloth 96. In addition, controlled movement of the elevator 12 in the upward direction is generally effected after removal of sheets from the stack, thus maintaining the stack face at substantially the same level as each pickoff cycle begins.

When the work head 16 is moved to the desired location to deposit the sheets, the switch LS2 is effective to pressurize the pipe 118 moving the stripper member downwardly to the position shown in FIG. 3, closing off the vacuum through the portion 68 and stripping the sheets or sheets from the planar surface 88 of the shroud 86 by means of projection of the legs 1 l2, 1 14.

Referring now to FIGS. 2 and 3 taken in conjunction with FlG. 5, it will be noted that the relative axial position of the shroud 86 in effect limits the extent of the pointed card cloth 96 which is presented and exposed to the stack of sheetsl Thus, relative movement between the card cloth 96 and the surface 88 of the shroud 86 causes less or more of the teeth to be exposed to the face of the stack S.

The threads on portion 84 are chosen such that a very small rotation of the nut 80 is effective to present an extent of the tooth T1 of sufficient length to impale either the single sheet Ll, sheets L1 and L2, or three sheets L1, L2 and L3, as is depicted in FIG. 5 of the drawings.

In addition, should sheets of less thickness or different material be encountered in a subsequent stack to be fed, adjustment of the shroud 86 may be simply made to accommodate the sheet thickness or different material.

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 as defined by the following claims.

We claim:

1. A device for transferringa selected number of flexible sheets from a stack, comprising a conduit having an opening to be positioned adjacent to the face of the stack of sheets, vacuum creating means connected to said conduit for drawing sheets of material toward said opening, pointed means for gripping a sheet disposed adjacent said opening, and means adjustably movable with respect to said gripping means for limiting the extent of said pointed gripping means presented and exposed to the stack of sheets, said adjustably movable means including a shroud member having a surface substantially covering said conduit opening, said surface having an opening through which the pointed means extends and another opening providing for flow of air into said conduit.

21A device in accordance with claim 1 wherein said adjustably movable means comprises a shroud member substantially covering said conduit opening, the shroud member having a planar surface with a slotted opening provided through which pointed elements of said pointed means extend, and a pair of slotted openings disposed one on each side of the pointed elements providing for flow of air into said conduit.

3. A device in accordance with claim 2 which further ineludes means for stripping said material] from said pointed elements, the stripping means being disposed for movement from a position within the conduit and through said pair of slotted openings. t

4. A device for transferring a selected number of flexible sheets from a stack, comprising a conduit having an opening to be positioned adjacent to the face of the stack of sheets, vacuum creating means connected to said conduit for drawing sheets of material toward said opening, pointed means for gripping a sheet disposed adjacent said opening and means adjustably movable with respect to said gripping means for limiting the extend of said pointed gripping means presented and exposed to the stack of sheets, said adjustably movable means comprising a shroud member having a surface with an opening through which said pointed means extends, the shroud member being threadedly received in a nut rotatabl captive on the conduit whereby rotation of said nut 15 e ective to move the shroud member with respect to said pointed means.

5. A device in accordance with claim t 4 which includes resilient biasing means disposed between said conduit and the shroud member for substantially maintaining the shroud member in an adjusted position.

6. A device for transferring a selected number of flexible sheets from a stack, comprising a conduit having an opening to be positioned adjacent to ,the face of the stack of sheets, vacuum creating means connected to said conduit for drawing sheets of material, pointed means for gripping a sheet disposed adjacent to said opening, means for limiting the extent of said pointed gripping means presented to the stack of sheets, said limiting means having a planar surface provided with an opening through which said gripping means extends, and means for causing relative movement between said pointed gripping means and said limiting means to adjust the extent of said pointed gripping means presented to the stack of sheets.

7. A device-for transferring a selected number of sheets from a stack, comprising a conduit having an open end to be disposed adjacent to a face of the stack, means for drawing air flow through the open end, a nut rotatably mounted on said end, a shroud threadedly carried by the nut and adapted largely to close said open end and defining an elongated slot, and a pointed means extending in said slot, secured to the conduit, and keyed to the shroud to prevent relative rotation thereof when the nut is relatively rotated with respect to the shroud to adjust extent of exposure of the pointed means beyond the elongated slot.

8. A pickoff mechanism comprising a suction conduit having a pointed means affixed in one end thereof, vacuum creating means connected to the conduit remote from said end, a shroud in said end for limiting the extent of exposure of the pointed means to sheet material to be picked up, the shroud defining at least one air inlet adjacent to the pointed means, a sheet stripper movably mounted in the conduit and projectable through said shroud inlet beyond the pointed means, and power means operatively connected to the stripper and effective, when the latter is projected, to render said vacuum means ineffective.

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