US2919129A - Sheet feeding machine - Google Patents

Description

Dec. 29, 1959 R. L. SJOSTROM SHEET FEEDING MACHINE Filed July 26. 1956 2 Sheets-Sheet l INVENTOR.

1959 R. L. SJOSTROM SHEET FEEDING MACHINE 2 Sheets-Sheet 2 Filed July 26. 1956 ROM z JIDNVENTOR BY 7m United States Patent SHEET FEEDING MACHINE Robert L. Sjostrom, Miami Beach, Fla.

Application July 26, 1956, Serial No. 600,191

8 Claims. (Cl. 271-33) The present invention relates to a device for successive removal of individual sheets of material from a stack of sheets and the successive delivery of the sheets to a desired location.

In the textile and laundry field, there has always been considerable diiiiculty in removing sheets, towels, pillowcases or other similar elements from a stack and delivering them individually to some desired location, such as an ironer or folding machine. Attempts have been made to satisfy this problem by removal of the sheets with the use of suction cups and fingers. However, attempts of this nature have uniformly failed for a number of reasons. Attempts have been made in the paper industry to feed sheets of material with the use of an adhesive material; while devices used for this purpose in the paper field may have been satisfactory for that type of operation, the machines are not suitable for delivery of textile materials for the means of stripping the sheet material from the adhesive are not positive and consequently do not provide a certainty of operation.

The present invention is directed towards a device of the type generally indicated in which individual sheets are picked from the top of a stack by an adhesive material. The sheet material is subsequently removed from the grip of the adhesive material by a positive acting arm which is actuated at a selected position.

In the present invention, the adhesive material is provided in the form of a roll of adhesive tape with means providing a fresh surface of tape for each new sheet of material being picked up. Used tape is rolled onto a second spool.

The stripping of the sheet material from the adhesive surface and the provision of a fresh surface area of adhesive material for a subsequent operation are simultaneously provided from a common operating source actuated by a switch at a selected point.

There is also provided an automatically adjustable table to support the stack of sheet materials at a selected level for removal of the uppermost sheet from the stack.

These and other objects and advantages of the present invention will be more clearly understood when considered in connection with the accompanying drawings in which:

Figure 1 is a cross sectional somewhat schematic side view of the invention.

Figure 2 is an enlarged detail of one of the pickup units illustrated in Figure 1, and

Figure 3 is a detail of the supporting arm mechanism.

In this arrangement, a suitable frame 1 having suitable side, end and bottom walls is provided with a centrally located well section 2. A table section 3 is horizontally positioned in the well 2 and is supported at its end by arms 4 and 5. Each of these arms 4 and 5 are provided with bearings 6 and 7 respectively. These bearings in turn thread onto the shafts 8 and 9 respectively and are adapted to move up and down on the shafts when these shafts are rotated. The shafts are suitably mounted for rotation in bearings 10, and each is provided with bevel gears 11 at their lower end. A common operating shaft 12 provided with bevel gears 13 at either end interengages the bevel gears 11 and is thereby operatively connected to them. The shaft 12 is connected to a reversing motor 14 through a, suitable arrangement, such as the interengaging gears 15. The motor 14 is thus able to raise and lower the table 3 through rotation of the shaft 12 and consequent rotation of the shafts 8 and 9. The shafts 8 and 9 should be provided with opposing threads in the particular modification of the invention shown in the drawings.

The motor 14 should be provided with a suitable on-olf and up-down control for proper movement and control of the table 3. A limiting switch 16 should also be connected in series with the up control to the reversing motor 14. This limiting switch 16 is supported on the arm 17 which is fixed at its other end 18 to the top of the frame 1. The switch 16 may be a mercury switch adapted to close the circuit through the motor when the master switch is closed to permit an upward movement. This limiting switch 16 has a contacting wire 19 secured at one end to the mercury elements of the mercury switch and the other end curved downwardly and adapted to engage the upper surface 20 of the stack of sheet material. The finger 19 will normally move downwardly closing the switch 16. When this occurs, the motor 14 is energized and the table 3 moves upwardly until the top of the sheet material 29 engages the curve section of the finger 19 raising it and consequently opening the switch 16 and turning the motor 14 off. In this manner, the sheet material 2il'may be kept with its upper surface at a constant level suitable for the pickup elements of the present invention.

A pair of lever arms 30 are mounted on a transverse shaft 31 at the forward end of the present invention. The shaft 31 is in turn suitably mounted in bearings 32. A motor 33, suitably secured to the frame, interengages a lever extension 34 which is secured rigidly at one end to the shaft 31. This interengaging may be provided by a lever linkage system 35 comprising a lever arm 36 mounted on the motor shaft with a pin and slot arrangement 37 as illustrated. Thus, the rotation of the motor 33 will cause a reciprocating action of the parallel arms 30 from a position above the stack of material 20 to a position beyond the present invention. A cross beam member 39 extends between the upper ends of the parallel arms 30 and is secured rigidly to them. On this cross beam 39 there is mounted a pair of pick-up elements generally designated 49. These pick-up elements 49 are secured against lateral movement along the beam or shaft 39 by suitable means, such as retaining rings at adjustably spaced positions. The pick-up unit 40 is provided with a T-shaped frame having outwardly extending arms 41 and 42 and a downwardly-extending arm 43. A pair of drums or rollers 45 and 46 are mounted on the shafts 43' for rotation with the shafts 43 in turn mounted on the arms 41 and 42 towards the outer ends thereof. At the lower end of the member 43 there is mounted for free rotation, a roller or small drum 47, which may be rotatably secured to the member 43 by the shaft 48. A roll of adhesive tape 49 is mounted on the drum 46, and it has its end threaded downwardly under the roll 47 and up onto the drum 45.

The shaft 43' extends through the arm 41 and is rotatably mounted in it. This shaft 43' has a gear 50 secured at its end on the side opposite the side onwhich' the drum 45 is secured. Also secured on the opposite side of the supporting frame is a solenoid 51 having a downwardly-extending plunger arm section 52 and an upwardly extending plunger 53. At the lower end of the plunger arm section 52 there is secured a stripper arm 54 which is provided with a flange section extending inwardly towards the roller 47 but terminating just short of it. At the'upper end of the solenoid secured to the plunger section 53 there is secured a lever arm 56 pivotally engaged n57 to the plunger 53 at one end and pivotally engaged at the other end 58 to the pawl 59. The pawl59 is pivotally secured to the arm 41 by a pin 60 and has a tooth-engaging section 61 projecting beyond and adapted to successively engage the teeth 62 on the gear 50. The plunger 53 and 52 are maintained in a normal up position by the spring 65 connected at one end to the lever 56 and at the other end to the supporting frame. A spring detent 70, secured at one end 71 to the arm 41, is adapted to engage the teeth 62 and prevent slipping of the drum 45. The solenoid 51 is controlled electrically by a switch 80 which may be located on the lever arm 30. The limit switch 80 is adapted to be engaged by the trip element 81. The trip element 81 may be adjustably positioned on the bearing or support element 32 or in some other suitable manner so that the trip element 81 will engage the switch 80 at any selected position of rotation of the arms 30. When the switch 80 is engaged, the solenoid 51 is actuated. This moves the plunger arm downwardly causing the stripper to bear against sheet material which has previously been adhered to the strip of adhesive material extending over the roller 47. The arm 54 is sufficiently close to the roller 47 and moves sufiiciently beyond it to disengage the sheet material from the adhesive. Simultaneously, the pawl 59 moves the gear 50 one notch, turning the drum 45. and consequently unrolling the adhesive material from the drum 46 onto the drum 45. The amount of adhesive material so unrolled is dependent upon the number of teeth on the gear 50, preferably a quarter of an inch of tape is unrolled in each cycle. Normally, the solenoid 51 is actuated when the arms 30 have positioned the pick-up element 40 at a point such as 90. At this point the forward edge of the uppermost sheet material, which has been picked from the stack 20, may be deposited onto a successively positioned machine, such as a folding machine. The operation of the motor 33 then reverses the movement of the arms 30 whereby the pick-up elements 40 are returned to the stack of material 20 for a successive operation. The pick-up unit 40 may be provided with a limit switch 91 having a finger member 92 which controls the limit switch and is adapted to bear against the tape at 93. This limit switch 91 is connected in series with the motor 33 so that when the tape accidentally breaks, the limit switch 91 is opened, thereby causing the motor 33 to stop permitting an immediate replacement of the tape or other repair to it.

, If desired, the two pick-up units 40 positioned on the shaft 39 may be selectively positioned along the shaft 39 to adapt the machine for use with stacks of material of diiferent widths.

The pick-up elements 40 must be maintained in a vertical position in order to ensure the proper operation of the present invention. To accomplish this the pick-up element40 is keyed to the shaft 39 by suitable means, such as a key element 101. The shaft 39 is freely rotatable in the arms 30. At one end of this shaft 39, preferably positioned beyond the arms 30, there is also keyed a sprocket 102 by a suitable keying element such as indicated at 103. V The sprocket 102 is inter-engaged with the sprocket 104 by the chain 105. The sprocket 104 is fixed on a sleeve 106 which is in turn fixed to the frame or some other suitable member such as the bearing 32; thus, as the arms 30 are pivoted back and forth by the action of the shaft 31 to which these arms 30 are keyed, the sprocket and chain arrangement will tend to keep the pick-up elements 40 in a normal vertical position.

Having now described my invention, I claim:

1. In a device for delivering individual sheets from astack of sheet elements, a pick-up element comprising rotatable drums, a length of adhesive material wound at spaced positions on said drums, bearing means over which said material extends intermediate said drums with said adhesive material providing a contact area for engagement With a sheet element, a stripping arm having a projecting portion positioned adjacent to said bearing means, a solenoid operatively engaging said stripping arm and adapted to project it from a position normally above to a position below said bearing means, and means operatively interengaging said solenoid and adhesive material for advancing said adhesive material over said bearing means.

2. In a device for delivering individual sheets from a stack of sheet elements, a pick-up element comprising a supporting frame member, rotatable drums mounted on said frame member, a length of adhesive material wound on said drums with an intermediate portion facing downwardly, a bearing means for and positioned above said intermediate portion, a stripping arm having a projecting downwardly movable arm, a solenoid operatively engaging said arm and adapted when actuated to move it from a position normally above to a position below said bearing means, and means including a pawl and ratchet operatively engaged with said solenoid for advancing said adhesive material over said bearing means.

3. A device for delivering individual sheets from a stack of sheets comprising in combination a self-adjusting table for receiving a stack of sheets with means for maintaining the upper surface of the same at a constant level, a pick-up unit having means supporting an elongated strip of adhesive material with said adhesive material for engaging a sheet, means providing a bearing surface for a section of said material, means for vadvancing said mate--,

rial in intermittent increments over said bearing surface,v stripping means for removing said sheet from said adhesive material and means for synchronously actuating said stripping means and said means for advancing.

4. A device for delivering individual sheets from a stack of sheets comprising in combination a plurality of pickup elements each comprising a frame, rotatable drums mounted on said frame, a length of adhesive material Wound on said drums with an intermediate portion facing downwardly, a bearing means for and positioned above said intermediate portion, a stripping element mounted on said frame and including an arm positioned for longitudinal movement between points just above and below said bearing means, arm actuating means, a frame member mounting said pickup elements in parallel, means for moving said frame over an arcuate sector to and from a point above said stack, and means for synchronously actuating said last mentioned means and said arm actuating means.

5. In a device for delivering individual sheets from a stack of sheets, a pick-up element comprising a length of adhesive material, means mounting said material for engagement with an individual sheet, means having a movable stripper arm, and solenoid means operatively engaging and said arm for moving saidarm beyond but adjacent to said material whereby said arm is adapted to contact and remove said individual sheet from said material.

6,. In a device for delivering individual sheets" from a stack of sheets, a pick-up element comprising a length of adhesive material, means mounting said material for longitudinal movement, bearing means over which said material extends with said material providing a contact area for engagement with an .individual one of said sheets, means havinga projecting stripper arm, means for actuating said arm to a positionbeyond but adjacent said material in a plane normal to said sheets at the point of contact of said material to strip it from the adhesive material, and means for synchronously actuating said means for actuating said arm and longitudinally advancing said adhesive material. g V

7, In a device for delivering an individual sheet from a stack of sheets, a pick-up element comprising rotatable drums, a length of adhesive material wound at spaced positions on said drum, bearing means over which said material extends intermediate said drums with said material providing a contact area for engagement with said sheet, means having a projecting stripper arm, means for actuating said arm to a position beyond but adjacent said material in a plane normal to said contact area to strip said sheet from the adhesive material and means for simultaneously actuating said arm and advancing said material over said bearing means.

8. In a device for delivering individual sheets from a stack of sheets, a pick-up element comprising a frame, rotatable drums mounted for rotation on said frame, a length of adhesive material wound from one drum to the other, bearing means under which said material extends intermediate said drums with said material providing a contact area for engagement with a sheet, means mounted on said frame having a projecting stripper arm positioned adjacent to and just above said bearing means, actuating means operatively engaging said arm and adapted to project said arm below said bearing means for disengaging said material and sheet, and means operatively interengaging said actuating means and drums for intermittently advancing said adhesive material over said bearing means in a synchronized movement with the operation of said actuating means.

Dvorak Apr. 16, 1901 Rider June 13, 1944

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