US1954480A - Sheet separating method and apparatus - Google Patents

Description

April 10, 1934. E, HUNTER 1,954,480

SHEET SEPARATING METHOD AND APPARATUS Filed May 51, 1932 ,2 Sheets-Sheet l INVENTOR Patented Apr. 10, 1934 SHEET SEPARATKNG METHOD AND APPARATUS Percy E. Hunter, Pittsburgh, Pa.

Application May 31, 1932, Serial No. 614,604

15 Claims.

My invention relates to a method of and apparatus for separating sheets, and more particularly to the separation of metal sheets such as are hot-rolled in packs. The invention is also ap- 'iplicable to the separation of metal sheets after they have been box annealed, or which are bound tightly together through the annealing process and their own weight.

In the hot rolling of lighter gauges of sheet 9" metal the sheet bars are passed repeatedly through rolls until they are of sufliciently reduced thickness, and are doubled and reheated repeatedly until the original bars may consist of eight or more sheets in a single pack. The rolling pres- '1 sure causes the sheets or layers of the pack to adhere tightly together and these packs must be opened or separated after they have been sheared. In the process of shearing packs, the edges of the thin sheets are dragged down or burred over one another, and in some cases where the shear knives are dull, the drag on the upper sheet may carry it down over the edge of the entire pack, thereby causing the sheets to be more tightly bound together.

The sheets of the pack are commonly separated or opened by bending one corner of the pack to effect slight separation of the sheets at such corner, and then manually stripping the sheets oii, one by one. Even under favorable conditions this is a tedious and laborious operation, and when the sheets stick together tighter than usual, tools such as wedges are required to separate the sheets. In many cases, the sheets become damaged and have to be scrapped.

This invention relates to a method for opening packs by bending a pack close to the sheared edge at one or more corners or along one or more sides, very abruptly, by means of rolls or dies, so as to overcome the strength of the adhesion between sheets and to break the mechanical bond formed in shearing the pack. This is accomplished by bending the corners or sides of the pack as close to the sheared edge as possible around as small a radius as practical, in order to stretch the sheets a minimum amount and draw the edge of each sheet away from the edge of the sheet adjacent thereto. If a pack be bent around a large radius for the same number of degrees, the difference between the length of arc on the inside and on the outside of the pack would be the same as for the same thickness of material bent around a smaller radius, but the length of arc would be much greater, and the material would therefore stretch more and not exert as great a pull between adjacent sheets forming the pack.

The adhesion between the individual sheets is so great that if a pack be bent over a large radius the individual sheets will be stretched, but if bent over a very small radius close to the edge of the pack, the strength of the material is greater than s the adhesion and will cause one plate to slip over the other, overcoming the adhesion and destroy the mechanical bond, and a reversal of the bend will cause the edges of the individual sheets to fan out surhciently to either to permit getting hold of the individual sheets to pull them apart, or to introduce a separating force between the individual sheets.

Some of the ways in which my invention may be practised are shown in the accompanying drawings, wherein Figure l is a longitudinal sectional view of a machine; Fig. 2 is a cross sectional view of the press or bending mechanism; Fig. 3 is a View taken on the line III-III of Fig. 2, showing pack ejector actuating mechanism; Figs. 4, 5 and 6 are fragmentary views of the press of Fig. 2, showing the bending elements of one side thereof in various positions of bending movement; Fig. 7 is a sectional plan view of a portion of the structure of Fig. 1; Fig. 8 is a view taken on the line VIII-VIII of Fig. 7; Fig. 9 is a vertical sectional view showing another form. of sheet separating aparatus; Fig. 10 is a fragmentary plan view thereof, and Fig. 11 shows another manner in which adhering sheets may be separated.

Two opposite edges of a pack are bent on a bending machine or presser 12, as above-explained, the pack then being passed through fiattening rollers indicated at 13, and t0 the separating or opening apparatus indicated at 14 (Fig. 1).

The presser comprises side frame members 15 held in assembled relation by bolts or tie rods 16 and a base plate 17. The base plate 17 is mounted between and secured to the side frame members 15 and is shown as supporting plunger housings 18 in position adjacent to the side frames, each housing carrying plungers 19 that are yieldably held in their uppermost positions by springs 20 that surround bolts 21 which limit upward movement of the plungers. Each housing 18 has a pair of upwardly-extending ribs or projections 22 about which the edges of a pack 23 are bent as shown in Figs. 4, 5 and 6, and as hereinafter described.

A cross head or presser head 25 is disposed between the frame members 15, and has extensions 26 at its ends that are slidably supported in ver tical guideways formed in the sides of frame members 15. The presser head 25 is reciprocated vertically by means of a crank shaft 27 that is journailed in the uper edges of the frame members 15, and is driven from any suitable source of power. Connection between the cranks of the shafts 2'7 and the presser 25 is had through a pair of links or connecting rods 28.

The presser 25 supports plunger housings 29 in alignment with the plunger housings 18, the housings 29 carrying plungers 30 that are yieldably held in their lowermost positions by springs 31, bolts 32 being provided to limit downward movement of the plungers. Four plungers 30 and four plungers 19 are shown in the drawings, and these can be varied in number to suit various conditions, such as the sizes of packs upon which it is desired to operate. A slot 33 is provided near each side of the presser 25, and the outer walls of such slot are inclined as at 34 to provide a pack-centering and bending surface for the pack. That portion of the slot wall immediately above the bevelled portion 34 may be roughened or serrated as shown at 35 in Fig. 4, in order to exert a striping or abrading action on the edges of the sheet to loosen the same.

When a pack of sheets has been placed in the bending machine, the shaft 2'7 is set in motion to lower the cross head. As the cross head descends, the opposite longitudinal edges of the pack are engaged by the inclined walls 34 to center the pack, and then bend it down, as shown in Fig. 4, the pack being gripped between the pairs of cooperating plungers 30 and 19, to prevent movement of the pack during bending of its edges.

Continued downward movement of the presser head 25 carries the plunger housings 29 into engagement with the pack, as shown in Fig. 5, and bends the edges of the pack around the ribs 22, through movement of the pack bodily in a direction perpendicular to its plane. In Fig. 5 this second bending operation is shown in its initial stage, at which time the edge of the sheets of the pack are caused to be moved across the serrations 35 and across the ribs 22. The springs 31 may yield sufliciently to permit the plungers 30 to go solid, and the pack 23 is bent to the position shown in Fig. 6.

During the final stage of this second bending operation the springs 20 are compressed, while the pre-bent edge portions of the pack are pulled across the ribs 22 and then bent in the opposite direction, thereby reversing the drawing or slipping action of the edge portions of the sheets relative to each other. The extent of movement of the pack during the second bending operation is such that the entire edge portion at opposite sides of the pack is re-bent to a position at right angles to the plane of the pack. This operation is expeditiously effected by merely moving the pack relative to the ribs 22 a distance substantially equal to or greater than such width of the edge portion of the pack as is desired to subject to the bending operation.

During the raising movement of the presser head 25 the springs 20 and their plungers 19 will raise the pack from between the bending ribs 22.

' When the presser head 25 is raised sufficiently, the

pack is released from the gripping force of the plungers l9 and 30 and a cam 35' carried by the shaft 27 engages a lever arm 36 pivotally secured at one end to one of the side frames 15 (Figs. 1, 2 and 3). The other end of the arm 36 is secured to a rod 37 which is connected to a lever arm 38, the arm 38 being carried by a shaft 39 that is suitably journalled at its ends to the side frames 15. The shaft 39 carries an arm 40 which has connection with one end of a rod or link 41, the other end of the link 41 being connected to a rod 42 which extends between a pair of rocker arms 43. The arms 43 are pivotally secured at their lower ends to the base plate 17, their upper ends being disposed to the rear of the pack of sheets in the presser machine.

As the arm 36 is swung upwardly by the action of the cam 35, the rocker arms 43 are moved into engagement with the rear edge of the pack by the connections above-described and the pack is moved forwardly to the flattening rolls 13. At the end of the lifting movement of the cam 35, the cam passes out of engagement with the arm 36 and a spring 44 secured to the lower end of the rod 37 causes the rocker arms 43, and the operating connections to assume their normal positions. The pack-ejecting mechanism is preferably actuated and restored to its normal position before the completion of the lifting movement of the cross head 25, so that another pack of sheets may conveniently be inserted in the presser machine.

As shown more clearly in Fig. 7, the first of these rolls 46 has its ends tapered, so that the ends will force the sharply upturned edges of the pack 23 outwardly and downwardly, the said edges of the pack being initially bent downwardly through the impact thereof with the rolls under the action of the above-described advancing mechanism. The next roll 47 is of smaller taper at its ends to force such bent edges further toward flattened position, while roll 48 completes the flattening of the sheet.

As explained heretofore, this operation results in loosening of the sheets at the edges of the pack, and I effect complete separation or opening of the sheets by means of air or other fluid pressure, as hereinafter described.

As the packs leave the flattening rolls, they enter between two conveyer belts 52 and 53 that are driven in any suitable manner, the adjacent sides of these belts traveling in the same direction. The upper belt 53 serves primarily to prevent too great vertical movement of separated sheets, and to advance any sheet which is blown into contact therewith. The belts, of course, pass around suitable pulleys which are driven in any convenient manner.

An elongated orifice 54 is positioned at each side of the conveyer belts, and is supplied with fluid pressure from a supply line 55 and branch pipes 56. As the sheets are advanced by the belt 52, with their longitudinal edges extending into the slots 54, air or other fluid under pressure is blown against the edges of the sheets and enters between the sheets of the pack. The edges of the sheets need not be previously separated or loosened throughout their length, since even if only small openings are present for the entry of fluid pressure, the force of such pressure will be multiplied many times over the surfaces of the sheets, and the expansive separating force is very great even with relatively low air pressures. The lower run of the belt 53 is spaced such distance above the upper run of the belt 52 that it will not interfere with the necessary separating movement of the sheets.

In order that packs of sheets of various widths may be operated upon, the presser machine, the flattening rolls and the separating apparatus are made adjustable. In the presser machine, one of the plunger housings 29 is slidably supported or hung on the cross head 25 by means of flanged ribs 60, the ribs extending throughout slots in the cross head.

A stud bolt 61 is threaded into the housing 29,- and extends through the side of the cross head and through the side frame 15. A hand wheel 62 is rotatably mounted on a bracket 63 which is secured to the side of the cross head 25, the frame 15 being cut away sufiiciently to permit vertical movements of the bracket due to vertical reciprocation of the cross head. The bolt 61 has threaded connection with the bushing of the hand wheel, so that when the wheel is rotated in one direction or the other, the plunger housing will be moved toward or away from the plunger housing 29 at the opposite side of the machine. Likewise, the plunger housing 18 beneath the adjustable housing 29 is adapted to be moved toward and away from its opposite housing 18, by means of abolt 64 and hand wheel 65. If desired, each of the plunger housings 29-29 and l818 may be made adjustable.

As to the rolls 46, 47 and 48, they are provided with clamps or set screws 49 by means of which the set of rolls at one side of the machine, or both sets, may be secured to their shafts at the, desired position for packs of varying widths.

With respect to the separating apparatus, the elongated nozzle 54 is shown as slidably supported on a bracket 57 and adjustable toward and from the edges of the pack by means of a screw 58 that has threaded engagement with the nozzle (Figs. '7 and 8). This adjustment permits the nozzle to be brought to proper position with respect to packs of varying widths. The nozzle at the other side of the pack may or may not be adjustably mounted.

Referring now to Figs. 9 and 10, I show a holding frame '70 for a pack. The upper and lower edges of the pack may be flexed or bent and then straightened, previous to placing them in the holder, if desired. At its lower edge, the holder carries an elongated flared mouth nozzle 71, and at its upper edge a nozzle '72. These nozzles correspond to the nozzles 54 and are supplied with fluid under pressure, from a suitable source. If desired, one of the nozzles can be dispensed with, and fluid pressure supplied only at one edge of the pack, since the fluid pressure can be directed entirely through the pack from one side thereof, but I prefer to supply the fluid pressure from two opposite edges of the pack.

The frame '70 is provided with verticallyspaced guide bars '73 that are flared at their ends to facilitate sliding of a pack into the nozzles and at their intermediate portions, serve as retaining bars to partially confine the sheets so that they will not be blown too far apart, the bars, however, having spaced relation to the sides of the pack so that a proper sheet separation may be effected.

In Fig. 11, I show a hand tool which may be employed, particularly when two sheets have not been entirely separated when operating upon the pack as a whole. This tool consists of a widemouthed nozzle 74 supplied with fluid pressure, and is inserted between the sheets and may be moved to bring it in proximity to adhering portions of the sheets, thereby more effectively concentrating the fluid pressure than if the nozzle were left in a fixed position at one edge.

The bends at the edges of the sheet, as shown in Figs. 4 and 6, are made as closely as possible to the edge thereof. For example, the first bend may be made at approximately /4 inch from the edge of the pack, and with a inch radius, to more effectively overcome the adhesion of the sheets, and break the mechanical bond thereof,

as set forth, at length heretofore. The separating force is very great when bending the pack to a 90 are within so small a radius, and much greater than in the case of a 90 are bent on a one inch radius, for example.

While I have herein more specifically described the bending of sheets along one or more edges, it will be understood that the invention contemplates also the bending of packs along diagonal lines, from edge-to-edge, adjacent to the corners of the packs, and introducing fluid pressure between the sheets at those portions of the edges which are adjacent to the corners.

The structure of Figs. 1 to 6 may, of course, be employed in the bending of the packs along the diagonal lines at the corners, the packs being placed in the machine in a diagonal position instead of with their edges parallel to the sides of the machine. The bending of the packs across the corners instead of along their longitudinal edges has the further advantage that a single machine, without adjustment of the bending ele ments, may be employed to bend packs of various sizes, by turning the packs toproper diagonal position, so that their corners are under the bending elements 19. Thus a wide pack would have its edges placed parallel to the horizontal axis of the machine, and a small pack might be so placed that a line connecting diagonal corners would be perhaps at right angles to the path of movement through the machine.

I claim as my invention:-

l. Apparatus for separating sheets of a pack which comprises an elongated nozzle for receiving the longitudinal edge of a pack, means for supplying fluid under pressure to said nozzle, a conveyer for carrying the pack along said nozzle, and a traveling conveyer member spaced abovethe first-named conveyer for limiting upward movement of the sheets and for advancing sheets engaged thereby.

2. The combination with sheet-pack bending means, of an ejector operated by the bending mechanism to discharge bent packs, flattening rolls for receiving and advancing said packs, a conveyer positioned to receive the packs advanced by the said rolls, and a fluid pressure nozzle positioned to discharge against the edges of packs while traveling with said conveyer.

3. The method which comprises bending one edge of a pack of sheets out of the plane of the pack, gripping the pack, and moving the same bodily in a direction perpendicular to its plane while maintaining the bent edge portion thereof,

along its axis of bending movement, against l movement in such direction, to cause movement of the bent portion across said axial line.

4. The method which comprises bending one edge of a pack of sheets in a given direction out of the plane of the pack, and moving the pack bodily in said direction while maintaining the bent edge portion thereof along its axis of bending movement, against movement in such direction, to cause movement of the bent portion across said axial line.

5. The method which comprises bending one edge of a pack of sheets in a given direction out of the plane of the pack, and simultaneously moving the pack bodily in said direction, while maintaining the bent edge portion thereof along its axis of bending movement, against movement in such direction, to cause movement of the bent portion across said axial line.

6. The method which comprises bending one edge of a pack of sheets out of the plane of the IGO- pack, gripping the pack, moving the same bodily in a direction perpendicular to its plane while maintaining the bent edge portion thereof along its axis of bending movement, against movement in such direction to cause movement of the bent portion across said axial line, restoring the bent portion to the plane of the pack, and introducing fluid under pressure, between the sheets, at said edge.

7. The method which comprises supporting one portion of a pack of sheets for bending movement on an axis parallel to the plane of the pack, gripping the other portion of the pack at points adjacent to said axial line, and bodily moving said gripped portion of the pack in a direction perpendicular to the plane thereof, to bend the pack along said axial line, and continuing the said movement to cause said one portion of the pack to enter the bending zone progressively.

8. The method which comprises bending one edge portion of a pack of sheets out of the plane of the pack, supporting said portion along its axis of bending movement against movement in a direction perpendicular to the plane of the pack,

gripping 1e pack at points adjacent to said axial line and moving the same in a direction perpendicular to the plane of the pack, to bend and move said portion in the direction opposite to the initial bending movement thereof, and applying fluid pressure, between the sheets, at said edge portion.

9. Sheet-separating apparatus comprising means for gripping a pack of sheets at points removed from an edge thereof, means for supporting the pack along a line adjacent to said edge, means for bending said edge of the pack at one side of said supporting means, and means engaging the pack adjacent to said supporting means and movable in directions perpendicular to the plane of the pack, for moving the pack bodily relative to said supporting means, thereby bending the pack at the other side of said supporting means.

10. Sheet-separating apparatus comprising means for gripping a pack of sheets at points removed from an edge thereof, a supporting member engaging the pack at one side along a line adjacent to said edge thereof, a pair of laterallyspaced bending members at the other side of the pack in position to receive said supporting member therebetween, and means for moving said bending members relative to said supporting member in directions perpendicular to the plane of the pack, and relatively past the plane of the pack, the pack being bodily depressed relative to said supporting member during the bending operation.

11. Sheet-separating apparatus comprising a pair of opposed presser members, for receiving one edge of a pack of sheets therebetween, one of said members being movable relative to the other member in directions perpendicular to the plane of the pack, a longitudinally-extending rib on the face of one of said members, means on the other member for bending said edge over said rib in opposite directions, and yieldably supported gripping devices carried by said members for engaging the pack along a line removed from the bending zone.

12. Sheet-separating apparatus comprising means for supporting a pack of sheets along a line spaced inwardly of an edge portion thereof, means for bending said edge portion downwardly at the outer side of said supporting means, and means movable in directions perpendicular to the plane of the pack, for depressing the pack bodily at the inner side of said supporting means, thereby rebending the bent edge portion in the opposite direction so that it lies in a plane substantially at right angles to the plane of the pack.

13. Sheet-separating apparatus comprising a pair of spaced parallel rails, for supporting a pack of sheets adjacent to opposite edges thereof, a cross-head above said rails, a pair of downwardlydepending bending members carried by said crosshead opposite each rail, each pair of bending members being laterally spaced to engage the upper side of the pack of sheets along lines adjacent to the outer and inner sides of the associated rail, and means for lowering said crosshead and mov ing said bending members below the plane of the pack, for bending said edges of the pack over the said rails in opposite directions, the pack being depressed between said rails during the bending operation.

14:. Sheet-separating apparatus comprising a pair of spaced parallel rails, for supporting a pack of sheets adjacent to the opposite edges thereof, a crosshead above said rails, a pair of downwardly-depending bending members carried by said cross-head opposite each rail, each pair of bending members being laterally spaced to engage the upper side of the pack of sheets along lines adjacent to the outer and inner sides of the asso ciated rail, and means for lowering said crosshead and moving said bending members below the plane of the pack, for bending said edges of the pack over the said rails in opposite directions, the pack being depressed between said rails during the bending operation, the lower ends of the outer bending members being inclined to engage one of said edges of the pack, for initially centering the pack relative to said rails.

15. The method which comprises bending a pack of sheets in one direction along a line adjacent to an edge thereof, gripping the pack adjacent to the bending zone, during the bending operation, and shifting the gripped portion of the pack in a direction to cause the bent edge portion thereof to be rebent progressively in the opposite direction by sliding movement thereof across the axial line of bending movement.

PER-CY E. HUNTER.

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