US3032340A - Sheet handling apparatus - Google Patents

Description

May 1, 1962 1.. LAWRENCE 3,032,340

SHEET HANDLING APPARATUS Filed May 23, 1958 INVENTOR.

LOUIS L.. LAWRENCE ATTOR EYS United States Patent 3,032,340 SHEET HANDLING APPARATUS Louis L. Lawrence, Newburgh, N.Y., assignor to Miehle- Goss-Dexter, Incorporated, Chicago, Ill., a corporation of Delaware Filed May 23, 1958, Ser. No. 737,366 9 Claims. (Cl. 271-68) This invention relates to sheet handling apparatus, and more particularly to apparatus for receiving and piling sheets of tin plate and other materials as the same are discharged from various processing machines.

One object of the present invention is to provide an improved sheet piling apparatus of novel, simple and durable construction that will receive and evenly pile a successive series of rapidly moving sheets of tin plate or other material without scratching their surfaces or otherwise injuring the same.

Another object of the invention is to provide an improved pile delivery for metal sheets wherein the successive sheets are caused to move in a substantially horizontal path until they are completely over piling position, whereupon said sheets will fall flatwise one on top of the other without relative sliding movement and form an even pile thereon, and each succeeding sheet will be prevented from dragging along the upper surface of a preceding delivered and piled sheet.

Another object of the invention is to provide in a pile delivery for metal sheets a novelly arranged stationary magnet means for receiving, guiding and suspending successive sheets of metal in a substantially horizontal path of movement into the space over the piling position and simultaneously causing the forward speed of said sheets to be decelerated whereupon said sheets will fall flatwise one on top of the other.

A further object of the invention is to provide in a pile delivery for sheets of metal or other material a novel sheet jogging means for limiting the forward movement of each sheet and accurately aligning the successive sheets as they are piled so as to form an even pile thereon.

A still further object is to provide in a pile delivery for sheets of metal or other material a novel sheet jogging wherein said apparatus is rhythmically returned to a starting position after each actuation.

A still further object is to provide in a pile delivery for metal sheets a novel magnet means located in the downward path of sheets being delivered to a piling position to prevent the corner portions of said sheets from bending downwardly and marring the upper surface of a preceding delivered and piled sheet.

The above and further objects and novel features of the present invention will more fully appear from the following detail description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are not intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. 1 is a vertical logitudinal sectional view of a sheet delivery embodying the present invention and including a pile elevator, and

FIG. 2 is an enlarged vertical longitudinal sectional view of one of the front sheet jogging devices and the slow-down magnets as shown in FIG. 1, certain of the parts having portions broken away for purposes of clearer illustration.

Referring to the drawings, there is shown one form of a high speed sheet delivery apparatus embodying the present invention which is particularly adapted for slowing down and piling sheets of tin plate as the same are delivered to said apparatus at a speed of approximately 120450 sheets per minute from a combined drying or 3,032,340 Patented May 1, 1962 baking oven and sheet turnover unit employed in the processing or making of metal articles or containers. It will be understood, however, that the high speed sheet delivery apparatus disclosed herein may be advantageously and effectively employed in connection with other machines for slowing down and piling sheets of tin plate or other sheets of metal or other materials as the same are discharged from said machines.

In the illustrated embodiment, the sheets of tin plate pass in rapid succession from the baking oven and turnover unit with their treated surfaces uppermost onto a horizontally disposed endless conveyer 10 which advances said sheets at a high speed away from said unit to a pile delivery 11 wherein sheets are piled one on top of the other in an orderly pile for further handling thereof. Conveyor 10 comprises a plurality of transversely spaced and parallel endless belts 12 the rear ends of which pass around a suitable roller or rollers (not shown) located adjacent the discharge end of the sheet turnover mechanism. The front ends of belts 12 pass around a plurality of rollers 13 which are fixed in spaced relation on a transversely extending shaft 14. This shaft is jounalled at its opposite ends in suitable bearings provided in rear uprights 16. Uprights 16 form part of the pile delivery frame which includes two transversely spaced similar front uprights 17, said uprights being bolted to the machine foundation and connected together by the side members 18. The front uprights 17 are connected together at the tops thereof by a stay shaft 20, the rear uprights 16 are connected together at the tops thereof by a stay shaft 21, and at vertically spaced points below the belt roller shaft 14 by cross members 22 and 23.

The belts 12 are continuously driven to advance the sheets of tin plate at a high rate of speed in a continuous ly moving procession from the baking over and/or turnover unit to the pile delivery 11, and said operation may be effected, as desired, directly from said unit or from a separate source of power, such as an electric motor carried by the pile delivery frame and connected by suit-- able known means with the belt roller shaft 14.

If desired, advancing rollers and cooperating pressure rollers may be located at the discharge end of conveyor 10 in the same manner as disclosed in United States Patent No. 2,626,800, granted Ian. 27, 1953, to George A. Martin, to further advance and guide the sheet as it leaves the endless conveyor.

In accordance with one aspect of the present invention, magnetic slow-down and supporting devices of novel construction are provided in the space over the piling position for the creating of magnetic fields to cause the sheet as it leaves the endless conveyor at a high rate of speed to be decelerated and at the same time to move forward in a substantially horizontal plane into space until approximately the entire sheet is disposed over the piling position. In this manner, the successive sheets are advanced under positive control to piling position, each succeeding sheet is decelerated, supported and suspended in space so that all surfaces of each sheet are free from contact with anything and is prevented from dragging along and marring the upper surfaces of a preceding delivered sheet, and upon reaching the pile will bodily fall flatwise on the top of the pile.

As shown in the drawings, the magnetic slow-down and supporting means comprises a plurality of permanently magnetized horseshoe- shaped magnets 24, 25 and 26. A lead-in magnet 24 is mounted adjacent the discharge end of conveyor 10 and slow-down magnets 25, 26 are mounted forwardly thereof. Magnet 24 with its open ends pointing downwardly is suitably secured to a ver end for vertical adjustment in slot 33 of block 27 and secured in adjusted position by a set screw 31. Block 27 is slidably mounted on parallel shafts 29 and 30 WhlCh are secured at their opposite ends to the side members 18 of the delivery frame. The block 27 and the magnet 24 carried thereby are therefore adjustable horizontally from side to side along the shafts 29, 30 and may be secured in any desired position of adjustment thereon by set screws 32.

As herein shown, the slow- down magnets 25, 26 are supported on an auxiliary frame comprising side members 34 and front parallel cross members 35, 36. Cross members 35, 36 are secured to brackets 37 slidablY mounted on the side members 34. Cross member 36 also supports sheet jogging devices hereinafter to be described in detail. The cross members 35, 36 and the magnets 25, 26 together with the sheet jogging devices carried thereby are therefore adjustable rearwardly and forwardly along the side members 34 and may be secured in any desired position of adjustment thereon by set screws 38 which are threadedly secured in brackets 37. The auxiliary frame is pivotally mounted at the rear thereof, as indicated at 39. The auxiliary frame is supported at the front thereof by laterally projecting brackets 41 secured in the front uprights 17. It will be noted that the pivotal mounting of the auxiliary frame enables said frame with the front magnets and the sheet jogging devices carried thereby to yield upwardly in the event the elevator of the pile support mechanism, to be hereinafter described, is accidently raised too high, thus preventing damage to the sheet jogging devices through engagement of the pile supporting platform therewith. The front magnets 25, 26 are supported by a bracket 42 comprising a vertically extending portion 43 and a horizontally extending portion 44. Bracket 42 is movably supported on parallel cross members 35, 36 and said bracket together with the magnets 25, 26 carried thereby are therefore adjustable horizontally from side to side along the cross members 35, 36 and may be secured in any desired position of adjustment thereon by the use of suitable set screws threadedly engaged through the upper portion of said bracket and into cross member 35. Magnets 25, 26 with their open ends pointed downwardly are secured at their top portions to a bar 49 which is suitably secured for example by bolts, to two longitudinally spaced vertically extending bars 50 the upper ends of which are adapted to fit into apertures 51 in horizontal portion 44 of bracket 42. Bar 49 has a series of horizontal apertures to permit bars 50 to be bolted thereto at several horizontally adjusted positions on said plate. Bars 50 are vertically adjustably secured in apertures 51 by set screws 52. Additionally, a series of vertically extending apertures in bar 49 permit the magnets 25, 26 to be mounted on bar 49 at a variety of positions in relation to each other.

Suitable shields 88, 89 are placed over the open ends of magnets 24, 25 and 26 to redirect a sheet should it accidently be misdirected out of its normal horizontal path of movement.

As the sheet leaves the conveyor 11 it travelsforward into space and its leading edge would normally tend to dip downwardly as shown by C in FIG. 1. Lead-in magnet 24 is mounted adjacent the end of the conveyor and slightly above the horizontal path of movement of the sheet and has a magnetic field 53 which extends downwardly and through said path. As the leading edge of the sheet enters into said magnetic field the lead-in magnet will attract said sheet and lift it sufliciently against the pull of gravity to keep it in a substantially horizontal and suspended path of movement. is so spaced that its magnetic field 53 is not strong enough to lift the sheet any more than to keep it in a straight horizontal path. Each of slow- down magnets 25, 26 like magnet 24- are horseshoe or U-shaped in cross section and each has a north and south pole, indicated at N and S with magnetic fields 54, 56, respectively, extending between said unlike poles. Said magnets are mounted'on However, the magnet bar 49 in a spaced apart position to each other with the adjacent poles of each magnet being unlike poles so that a further magnetic field 55 is created between said magnets. Magnetic fields 54, 55 and 56 extend downwardly into and through the horizontal path of movement of the sheet and present a magneticfield of a greater intensity than magnetic field 53. Magnetic fields 54, 55 and 56, however, are not of sufficient intensity to pull the sheet into physical contact with said magnets or to hold the entire weight of the sheet against the downward pull of gravity. As the trailing edge of the sheet leaves the conveyor, the leading edge thereof enters into the magnetic fields 54, 55 and 56 and is lifted upward and suspended in space by magnets 25, 26 and, at the same time, the intensity of these magnetic fields will cause its forward horizontal speed to be decreased. As the leading portion of the sheet enters the magnetic fields 54, 55 and 56, the weight thereof will overcome the magnetic influence of lead-in magnet 24 at the trailing edge there of causing said trailing edge to be pulled downwardly by gravity. Since magnetic fields 54, 55 and 56 will not support the entire weight of the sheet, it will be peeled downwardly away from said magnetic fields as the trailing edge thereof falls. As the trailing edge of the sheet falls downwardly and out of the magnetic field 53, the leading edge of the succeeding sheet enters into said magnetic field and the above described cycle is repeated, giving in effect a shingling of successive sheets in space. The entire forward speed of the sheet'is not absorbed by the magnetic fields 54, 55 and 56 with the result that each sheet continues to travel forward for a relatively short distance at the same time that it is being peeled away from said magnetic fields until the leading edge thereof strikes the front sheet joggers 60. As each sheet is fed into the space over the piled sheets at a high rate of speed, it is directed by and subjected to the following composite forces. First, the leading edge of the sheet is pulled upwardly by the magnetic force of lead-in magnet 24 which redirects the sheet into a substantially horizontal and suspended path of movement. As the leading edge of the sheet horizontally moves into the magnetic fields of magnets 25, 26, the'sheet is temporarily supported and suspended in space and is decelerated by said magnetic fields. Simultaneously with the action of m gnets 25, 26 on the leading portion of the sheet, its trailing edge has started to drop downward away from magnet 24 so that the sheet moves forward for a relatively short distance at an inclined angle which further tends to decelerate the sheet 'by air friction on the underside of said sheet and a slight compression of air beneath said sheet. The forward movement of said sheet is not completely decelerated as the leading edge of the sheet strikes the front sheet joggers 60 which causes the forward movement to stop whereby the sheet falls fiatwise by gravity a short distance onto a pile.

As shown in FIG. 1, the pile of delivered sheets is removably supported on a pile elevator of the type disclosed in the above-mentioned US. Pat. No. 2,626,800. The pile is lowered step by-step to maintain the top thereof at a selected minimum distance below magnets 24, 25 and 26, and this is accomplished by a ratchet 1th) drivably connected with the elevator and an oscillating pawl 99 engaged with said ratchet. The operation of thepawl and ratchet drive 99, 100 is controlled by a solenoid 117 which is operatively associated with a pawl cont-rolling mask 122 to normally hold the pawl 99 out of operative connection with the ratchet 106. Solenoid 117 is, in turn, oper'atively controlled by a switch which, in turn, is controlled by a movable arm 196 having mounted thereon a swingable lever 107 which lever is disposed inoperative relation to the top of the pile of sheets on the elevator. The construction and operation of pawl and ratchet drive 99, 100 is similar'to and is described in more detail in the above-mentioned US. Pat. No. 2,626,800. When the top of the pile of sheets is at a normal level below the swingable lever 107, the arm U 106 will not actuate solenoid 117 and the oscillating pawl 99 is held out of engagement with the ratchet 106 by the mask 122 and no downward movement will be imported to said pile. As the delivered sheets drop one after another on the pile, the latter thereby progressively increases and the lever 107 is prevented from pivotally swinging on arm 106 by said piled sheets, whereupon the arm 106 is moved to actuate the switch and the solenoid 117. The actuated solenoid in turn acts upon the pawl mask 122 to enable engagement of the pawl 99 with the ratchet 100 to rotate the latter and thereby effect downward movement of the pile thereon until the top of said pile again reaches a level below lever 107.

Disposed slightly forward of rollers 13 and supported on cross members 22, 23 of the delivery frame by means of forwardly extending bars 45, is a vertically extending metal plate 46 against which the successively delivered sheets are jogged as hereinafter described, and against which the rear edge of the pile of delivered sheets bears during lowering of said pile and the elevator as hereinbefore described. Suitably secured to the upper end of plate 46 are three vertically extending guides 47 having the inner edges thereof aligned with the inner surface of said plate and constituting an extension thereof. The upper ends of guides 47 have inwardly inclined surfaces 48 whereby as the sheets fall downwardly the rear edge thereof is guided into alignment with the inner surfaces of plate 46 against which they are jogged into an evenly stacked pile of sheets.

In accordance with another aspect of the invention, sheet jogging devices of novel construction and operation are provided to cause the successive sheets upon delivery thereof to the previously piled sheets to pile evenly thereon without relative sliding movement. In the illustrated embodiment four sheet jogging devices, indicated generally at 60, are employed at the front of the delivery and are identical in construction, mounting and operation, therefore a description of one of said front jogging devices will be sufficient for an understanding of the operation and function of all.

As herein shown, the front sheet jogging devices 60 are supported on the auxiliary frame described above in connection with the support for the slow-down magnets 25, 26. In FIGS. 1 and 2 of the drawings, each front sheet jogging device 60 comprises a front plate 62 and a rear plate 63 both of which are supported by and depend downwardly from a bifurcated collar 64 which is loosely mounted for pivotal movement on the cross member 36. Bifurcated collar 64 has a downwardly projecting leg 65 and a horizontally projecting leg 66 positioned at right angles to leg 65. The upper end of plate 63 is suitably secured to leg 65. The upper end of plate 62 is secured to the end of leg 66 by a hinge 67, said hinge permitting plate 62 to pivotally swing from its normally vertically position toward plate 63. Plates 62, 63 are thus pivotally mounted from their upper ends from the same support and when at rest depend substantially vertically downward and parallel to each other. Loosely mounted bifurcated collar 64 and plates 62, 63 are adjustable along cross member 36 and may be secured in any desired posi tion of adjustment thereon by a thumb screw 68 which is threaded into a collar 69 engaged over said cross member and disposed between the forked arms of collar 64. Collar 64 is provided with a pin 70 adapted to engage leg 66 as and for a purpose to be hereinafer described. The lower ends of plates 62 and 63 are resiliently connected by a spring 71. The vertical dimensions of plates 62, 63 are such that they extend a short distance below the normal level of the top of the pile of sheets. Extending along the front surface of plate 62 from the lower end to a point substantially above the horizontal path of movement of a sheet from the conveyor is an energy absorbing cushion 72 comprising, for example, a pad of ensolite, type 22226, manufactured by U.S. Rubber Company and covered with a sheet of neoprene Monarch is protect the ensolite from being 6 cut. Plate 63 is weighted by a weight 73 which is adjustably secured to a pin 74 that is, in turn, secured to the end of plate 63.

In the initial operation of the pile delivery, the described front sheet joggers 6f! are allowed to freely extend vertically downward and are moved along the side members 34 until the front surface of cushion 72 is spaced from plate 46 a distance equal to the length of a sheet to be piled. Joggers 60 are adjusted, along cross member 34, for the width of the sheet being fed and the desired spacing of the joggers along that width.

Accordingly, as each sheet is fed into the space over the pile support it is directed, supported and slowed down by the magnets 24, 25 and 26 as hereinbefore described, and the front edge of said sheet strikes the cushion 72, thus checking the sheet against further forward movement. Cushion 72 prevents damage to the front edge of the sheet as it strikes said joggers. The force of the sheet striking against cushion 72 will force the lower end of plate 62 to pivotally move forward against the resilient force of spring 71 which will be come compressed and transmit the force to the lower end of plate 63 which, in turn, will pivotally move forward as it absorbs the force transmitted to it. The shock absorbing force of plate 63 can be increased as desired by moving weight 73 outwardly along pin 74 away from said plate. The force of the sheet striking jogger 60 is thus absorbed by plates 62, 63 with a minimum of movement of said plates and the compressed spring 71 will return plate 62 to its vertical position where it will receive the impact of a succeeding sheet of a series being rapidly fed from conveyor 10. As the sheet is peeled away from the magnetic fields of slow-down magnets 25, 26, it will drop flatwise toward the pile along the pile guide 46 onto the pile and to a final position thereon with its rear edge engaged with the pile guide 46 and its front edge alinged with the front edges of the previously delivered and piled sheets. Thus, each sheet is deposited on the pile without sliding forwardly or rearwardly relative to the previously delivered underlying sheet and an even piling of sheets is obtained.

A plurality of front joggers 60, each freely and independently mounted, are used with four having been found to work satisfactorily at the high speed operation of this embodiment, although more or fewer joggers may be satisfactorily used with higher or lower speeds and/or with differing sizes of sheets to be piled. In the use of four front joggers a satisfactory operation is obtained by positioning two joggers side by side on each side of the leading edge of a sheet. In the operation of said jogger arrangement, the two inside joggers swing in unison and the two outside joggers swing in unison which is out of phase with the motion of the first set of joggers. Consequently, as one set of joggers is moving away from the pile of sheets and absorbing the impact of a delivered sheet, the other set is moving back to substantially vertical position in which position it is ready to absorb the impact of the next succeeding delivered sheet. Thus, there is a rhythmic operation of the front joggers whereby at least one jogger on each side of the sheet is in a sub stantially vertical position to absorb the impact of each successively rapidly fed sheet. As each jogger returns to its vertical position under the force of compressed spring 71, the cushion 72 will strike the leading edge of a sheet which is falling in space and before that sheet reaches the pile, thus effecting a jogging of each sheet in space and against the pile guide 46. It is also to be noted that as plate 62 returns to its vertical position the lower end of cushion 72 thereon strikes the top portion of the previously piled sheets to impart a rearward tap or thrust to said sheets whereby engagement of the same with the guide 46 and an even piling thereof is further assured. This novel construction and arrangement of front sheet joggers prevents said joggers from swinging excessively when struck by a forward moving sheet and assures that they will be returned to the vertical position in time to 7 absorb the impact of a succeeding sheet and also assures that a jogger Will be in proper position to absorb the impact from a series of successively fed sheets.

When replacing a full load with a new pile support, it is necessary to move front sheet joggers 60 forwardly and upwardly to obtain the proper clearance. To enable all of sheet joggers 60 to be moved simultaneously, a lever arm 84 is fixedly secured to cross member 36. As the lever arm is lifted upwardly, the cross member 36 and adjustably secured collar 69 are rotated causing pins 70 to engage and move leg 66 of bifurcated collars 64, thus causing all of the joggers 60 to be simultaneously moved forwardly and upwardly. A plate 85 having a notch 85 at its lower front surface is fixedly mounted adjacent the upper end of lever arm 84. A spring biased pin 87 is suitably mounted on the same side of arm 84 as plate 85 with said pin resiliently urged against the lower surface of the plate. Thus, as lever arm 84 is pivoted upwardly, pin 87 will be forced into engagement with notch 86 thereby locking arm 84 and joggers 68 in said upward position. Pin 87 may be manually retracted from notch 86, thus allowing joggers 60 to return to the operative position.

In accordance with another aspect of this invention, side magnet devices of novel construction are provided to prevent the corners of the leading edge of each sheet from bending downwardly as each sheet is delivered to the pile of sheets. In the illustrated embodiment two side magnet devices are employed, one on each side of the sheet. Since both side magnet devices are identical in construction, mounting and operation, a description of one will be sufficent for an understanding of the operation and function of both. Referring now to FIG. 1 of the drawings, each of the side magnet devices 62 comprises a vertically extending permanent magnet 75 which is U-shaped in top plan view or horizontal cross section, thereby forming north and south poles which are transversely spaced with respect to the vertical movement of the pile of sheets whereby a magnetic field horizontally extends into the downward path of the sheets being delivered to said pile. A vertically extending cover plate 76 having an inwardly inclined surface at the upper end and sides thereof is suitably secured across the open end of said magnet. A vertically extending support bar 77 is suitably secured at its lower end to the rear of magnet 75 and supported and guided at its upper end for floating movement in vertical and horizontal directions on horizontally disposed bracket 78. Bracket 78 is adjustably secured to cross member 35 by bolts 79 whereby each side magnet device may be adjusted for the width of the sheet being piled. A U-shaped plate 80 is bolted to the side of bracket 78 to provide a suitable slot 81 to slidably receive the upper end of magnot support bar 77. A series of apertures 82 in bracket 78 permits plate 86 to be bolted thereto at various places whereby forward and rearward adjustment of the support bar 77 on said bracket is possible. A pin 83 at the upper end of bar '77 limits its downward movement in slot 81. A plurality of apertures in support bar 77 permits pin 83 to hold said magnets at any desired vertical position. Side magnet devices 61 magnetically attract the outer corners of. the leading edge of the sheet as it falls downwardly'past said magnets. In a flexible sheet, the outer corners of the leading edge thereof will tend to bend slightly downward in which case these bent down corners will strike the surface of the preceding sheet and mar it. Side magnet devices 61, however, will magnetically attract these outer corners and as the sheet falls downwardly said outer corners willbe straightened out thus preventing said corners from striking and marring the upper surface of the preceding sheet. The side magnet devices can be mounted on or be used in cooperation with sheet side joggers of the type disclosed in the above-mentioned US. Patent No. 2,626,800 or with other types of sheet side joggers, or they can be mounted independently as shown in the embodiment.

While the present invention is herein illustrated and described in connection with the receiving and piling of metal sheets as the same are discharged from a combined drying oven and sheet turnover unit, it is equally adapted for the receiving and piling of metal sheets discharged from various other instrumentalities acting on such sheets. Moreover, the sheet jogging means is equally adaptable for the limiting of the forward movement and piling of sheets of non-magnetic character, such as cardboard and other sheets of similar relatively stiff non-metallic material which are fed substantially horizontally forward into the space above the piling position.

Various changes may be made in the design and arrangement of the parts of the illustrated embodiment without departing from the spirit and scope of the invention as will now be clear to those skilled in the art. It is therefore to be expressly understood that the present invention is not limited to the particular embodiment thereof herein illustrated and described.

What is claimed is:

1. The method of delivering metal sheets to a pile support comprising the steps of feeding sheets one after another generally horizontally into the space over said support, redirecting the leading edge of each sheet as it enters into said space into a generally horizontal path, temporarily supporting the forward portion of each sheet in said space to maintain each sheet in a freely floating and generally horizontal path of movement and simultaneously with said supporting causing the forward speed of each sheet to be decelerated, causing the rear portion of each sheet to fall downwardly as it is fed into said space whereby the entire sheet will be pulled downwardly by gravity, completely stopping all forward motion of each sheet when the same is completely over the pile support whereby each sheet will fall downwardly to a piling position, and feeding a succeeding sheet into said space as soon as the rear portion of the preceding sheet is pulled downwardly by gravity to thereby effect a shingling of sheets in space with the surfaces of each sheet free of contact with anything until it reaches the piling position.

2. In a sheet delivery apparatus the combination of a support for a pile of metal sheets, means toconvey metal sheets one after another into the space over said support, a first magnet positioned adjacent said conveyor means and having a magnetic field extending downwardly into and through th sheet path to lift the leading edge of each sheet but not to support the entire weight thereof against the pull of gravity and to direct it into a generally horizontal path of movement in said space, a second magnet positioned forwardly of said first magnet and having a magnetic field of greater intensity than said first magnet extending downwardly into and through the path of each sheet in said path. and adapted to temporarily suspend the leading portion of each sheet but not to support the entire weight of each sheet and to decelerate the forward speed thereof, whereby each sheet will be pulled downwardly by gravity and fall flatwise on said pile support.

3. In a sheet delivery apparatus as defined in claim 2 comprising means located adjacent the downward path of movement of the sheet to prevent the corners of the leading edge of each sheet from drooping as each sheet moves downwardly to the delivered position on said pile support.

4. A sheet delivery. apparatus comprising a support for a pile of metal sheets, means to convey a plurality of metal sheets in succession into the space over said support, a first magnet positioned adjacent the entry of each sheet into said space and having a magnetic field extending downwardly into and through the entrance path of said sheet and having an intensity sufiicient to lift the leading edge but not to support the entire weight of each sheet thereby redirecting each sheet into a generally horizontal and freely floating path of movement,

a second magnet positioned forwardly of said first magnet and having a magnetic field extending downwardly into and through the path of forward movement of each sheet, said second magnet having a greater intensity than said first magnet and adapted to temporarily suspend the leading portion of each sheet in said freely floating path but not to support the entire weight of the sheet and to decelerate the forward speed of each sheet.

5. A sheet delivery apparatus comprising a support for a pile of metal sheets, means to convey a plurality of metal sheets in succession into the space over said support, a first means providing an attractive force extending downwardly into and through said sheet path and located adjacent said conveyor means and above said space, said first means counterbalancing the pull of gravity on the leading portion of each sheet as it enters into said space and directing each sheet into a generally horizontal and freely suspended path through said space, a second means providing an attractive force of greater intensity than said first means and extending downwardly into and through said sheet path and counterbalancing the pull of gravity on only the leading portion of each sheet as it freely moves into said space to cause the forward speed of each sheet to be decelerated whereby as each sheet moves into said space the horizontal speed thereof is decelerated and the pull of gravity n the entire sheet overcomes said first and second means.

6. A sheet delivery apparatus comprising a support for a pile of sheets, means to convey a plurality of sheets in succession into the space over said support, a first means providing a magnetic supporting force extending into and through said sheet path and located adjacent said conveyor means, said first means counterbalancing the pull of gravity on the leading portion of each sheet as it enters into said space and directing each sheet into a generally horizontal and freely suspended path through said space, a second means spaced from said first means and providing a magnetic supporting force extending into and through said sheet path and counterbalancing the pull of gravity on only the leading portion of each sheet as it freely moves into said space and to cause the forward speed of each sheet to be decelerated whereby as each sheet moves into said space the horizontal speed thereof is decelerated and the pull of gravity on the entire sheet overcomes said first and second means.

7. In a sheet delivery apparatus as set forth in claim 3, wherein said last-mentioned means comprises a magnet element on each side of said path and each of said elements having a magnetic field extending horizontally into the sheet path whereby as each sheet falls downwardly past said magnets the downward movement of the outer edges thereof is retarded to straighten out the sheet as it is falling.

8. A sheet delivery apparatus comprising a support for a pile of sheets, means adjacent said pile support to convey a plurality of sheets one after another into the space over said support, a first means providing a vertical supporting force on the leading portion of each sheet and positioned adjacent said conveyor means and above the path of sheets into said space and extending downwardly into and through said sheet path, said first means counterbalancing the pull of gravity on the leading portion of each sheet as it enters into said space and directing each sheet into a generally horizontal and freely suspended path through said space, a second means spaced from said first means, said second means positioned above said sheet path and providing a vertical sup porting and lateral braking force on each sheet and extending downwardly into and through said sheet path and operable only on the leading portion of each sheet as the same moves into the forward portion of said space whereby as each sheet moves into said space the forward speed thereof is decelerated and the pull of gravity on the entire sheet overcomes said first and second means and the sheet falls downwardly onto said pile support.

9. A delivery apparatus comprising a support for a pile of metal sheets, means for carrying sheets one after another generally horizontally forward into the space over said support, magnetic means located above said pile support and above the forward portion of the path of each sheet in said space and having a magnetic field extending downwardly into and through the path of said sheet for temporarily supporting and decelerating the leading portion of each sheet while maintaining said portion free from contact with any object whereby the pull of gravity will cause the rear portion of each sheet to fall downwardly toward said pile support.

References Cited in the file of this patent UNITED STATES PATENTS 2,261,972 Matthews Nov. 11, 1941 2,332,863 Luehrs Oct. 26, 1943 2,374,174 Buccicone Apr. 24, 1945 2,517,388 Daves Aug. 1, 1950 2,566,240 Mursch Aug. 28, 1951 2,596,448 Toronto May 13, 1952 2,626,800 Martin Jan. 27, 1953 2,733,064 Martin Jan. 31, 1956

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