US2996297A - Magnetic sheet feeder - Google Patents

Description

Aug- 15, 1961 D. BucclcoNE MAGNETIC SHEET FEEDER 6 Sheets-Sheet l Filed Feb. 5. 1959 u Nt Aug. 15, 1961 D. BucclcoNE 2,996,297

MAGNETIC SHEET' FEEDER Filed Feb. 5, 1959 6 Sheets-Sheet 2 L lf rllrrnis Aug. 15, 1961' D; BucclcoNE MAGNETIC SHEET FEEDER Filed Feb. 5, 1959 6 Sheets-Sheet I5v si Ll;

Aug. 15, 1961 D. BucclcoNE MAGNETIC SHEET FEEDER 6 Sheets-Sheet 4 Filed Feb. 5, 1959 INVENTOR. pa rl'o Buccz'corze BY v MM# ma l Aug. 15, 1961 D. BucclcoNE 2,996,297

4 MAGNETIC SHEET FEEDER Filed Feb. 5, 3.959 6 Sheets-Sheet 6 Unite Stats arent O 2,996,297 MAGNETIC SHEET FEEDER Dario Buccicone, Gary, Ind., assigner to 'Bucciconi Eugineerng Co., Inc., Gary, Ind., a corporation of Indiana Filed Feb. 5, 1959, Ser. No. 791,'450 21 Claims. (Cl.\271-`16) liability of damage as the sheets are removed from the pile.

It is a more specific object of the invention to provide apparatus for the automatic feeding of metal sheets from the top of a pile thereof wherein each successive sheet is lifted along its entire length by a magnetic conveyor and advanced away from the pile without the use of pinch rolls and without metallic contact.

It is a still more specific object of the invention to provide an apparatus for removing successive metal sheets from the top of a pile thereof and for advancing the same therefrom in a rapid and eicient manner, wherein the sheets are lifted bodily from the top of the pile by an overhead magnetic conveyor which may be operated at a relatively high rate of speed and which will pick up each sheet and advance the same without disturbing the next succeeding sheet so that there is no contact between the successive sheets during removal from the pile nor subsequently and damage to the sheets It is another object of the invention to provide an apparatus for automatically feeding metal sheets from a pile wherein a magnetic conveyor is arranged above the pile and operated to lift each successive sheet, which conveyor raises the sheet vertically throughout its entire length and breadth, and thereafter conveys each sheet forwardly lwhile holding the same free of any metallic Contact, until the sheet is moved clear of the pile.

It is a further object of the invention to provide an apparatus for feeding metal sheets om a pile thereof |which comprises an upright supporting frame structure having a bed disposed therein on which a pile of sheets is supported and an overhead magnetic conveyor which is operated to remove successive sheets from the top of the pile and convey the 'same therefrom in a direction laterally of the pile, together with mechanism for raising and lowering the sheet supporting bed and mechanism for automatically controlling the same to maintain the top of the pile of sheets at a predetermined distance below the conveyor.

It is a still further object of the invention to provide an apparatus for feeding metal sheets from a pile which comprises a supporting frame having an overhead magnetic conveyor which is adapted to lift successive sheets from the top of a pile positioned on a bed disposed beneath the conveyor and to convey the sheets one by one in a direction laterally of the pile', a raising and lowering mechanism associated lwith the bed and control mechanism for determining the elevation of the top sheet in the pile and for automatically raising the bed as successive sheets are removed from the pile thereon.

Another object of the invention is to provide an ap- 7 paratus for unpiling metal sheets lwhich comprises a bed stmcture for supporting thereon a pile of the sheets, an

miice overhead magnetic conveyor which is operable to lift the sheets successively from the top of the pile and to forward the same away from the pile, mechanism for raising and lowering the bed structure, and an adjustable control mechanism for initially determining the elevation of the top sheet in the pile and for raising the bed structure as successive sheets are removed from the pile so that the topmost sheet is positioned a predetermined distance below the conveyor and successive single sheets are removed from the pile.

Still another object of the invention is to provide in a sheet feeding apparatus of the type which employs an overhead magnetic conveyor for removing the sheets from the top of a pile, a mechanism for separating the topmost sheets in the pile along the full length of the leading edge thereof, `which mechanism spreads the edges of the sheets in an upward direction toward the conveyor and facilitates the feeding of a single sheet at a time.

A further object of the invention is to provide in a sheet feeding apparatus having an overhead magnetic feeding conveyor a mechanism which is operative adjacent the leading edge of the sheets at the top of the pile for initially engaging and lifting the topmost sheet in the vertical direction toward the magnetic conveyor and for controlling the elevation of the pile so that the top sheet will be spaced from the conveyor a sucient distance for it to be picked up by the conveyor without picking up the next sheet in the pile.

Another object of the invention is to provide in a metal sheet feeding apparatus which is characterized by an overhead magnetic feeding conveyor, a mechanism for gripping the top sheet which is being fed from a pile adjacent the leading edge thereof and for lifting the same toward the magnetic conveyor so as to insure that the sheet will be held against the bottom of the conveyor in proper position for feeding.

Another object of the invention is to provide in a metal sheet feeding apparatus of the type which employs an overhead magnetic feeding conveyor a height gauging mechanism for determining Ithe elevation of the top surface of the top sheet in the pile rela-tive to the bottom surface of the conveyor which gauge mechanism includes gripper fingers for engaging the top sheet near its leading edge and for lifting the same toward the conveyor so as -to insure that the leading edge of the sheet is lifted clear of the pile and into the effective zone of magnetic attraction for holding the same against the bottom surface of the conveyor.

Another and still more specific object of the invention is to provide an apparatus for unpiling metal sheets which comprises an upright supporting frame, a bed structure for supporting thereon a pile of the sheets, an over-head magnetic conveyor which is operable to lift the sheets successfully from the top of the pile and to forward the same away from the pile, mechanism `for raising and lowering the bed srtucture, mechanism for energizing and deenergizing the magnets in the magnetic conveyor, and control mechanism for automatically determining the vertical position orf the bed and for operating the conveyor magnets in proper timed relation whereby each successive sheet is picked up bodily and fed from the pile without disturbing the neXt succeeding sheet in the top of the pile. l

Another object of the invention is to provide a sheet handling apparatus of the character described wherein the bed for supporting the pile of sheets comprises a plurality of rollers onto which the pile is initially moved and a brake mechanism cooperating with the rollers to retard the movement of the pile as it traverses the bed.

A further object of the invention is to provide a sheet handling apparatus of the type described wherein the operation of the magnets in the sheet forwarding con- Y veyor is electrically controlled by inducto switches or similar control elements which are actuated by passage of the sheets without any contact of the sheets with the control elements. Y

These and other objects and advantages of the invention will be apparent from a consideration of the sheet handling apparauts which is shown by way of illustration in the accompanying drawings, wherein:

FIGURE l is a plan view, with portions broken away, of a sheet handling apparatus having embodied therein the principal features of the invention;

FIGURE 2 is a side elevation of the apparatus, with portions brokenV away;

FIGURE 3 is an elevation of the loading end of the machine, with portions broken away;

FIGURE 4 is an elevation of the discharge end of the machine, with portions broken away;

FIGURE 5 is a cross section, to an enl-arged scale, taken on the line 5-5 of FIGURE 1, with portions broken away;

FIGURE 6 is a fragmentary cross section, to an enlarged scale, taken on the line 6 6 of FIGURE l;

FIGURE 7 is a cross section taken on the line 7-7 of FIGURE 6 on a larger scale;

FIGURE 8 is a fragmentary cross section, taken on the line 8-8 of FIGURE 46;

FIGURE 9 is a fragmentary cross section, taken on the line 9-9 of FIGURE 7;

FIGURE l() is a partial cross section taken on line 10-119 of FIGURE `6, to a larger scale and with portions broken away;

FIGURE 1l is a fragmentary section taken on the line 11-11 of FIGURE 10, to a larger scale;

FIGURE l2 is a fragmentary section taken on the line 12--12 of FIGURE l0, to a larger scale;

FIGURE 13 is a fragmentary section taken on the line 13-13 of FIGURE l0, to a larger scale; and

FIGURES 14 and l5 are diagrammatic layouts of the electrical controls for the apparatus.

The apparatus which is illustrated in the `drawings and which has incorporated therein the principles of the invention is designed to remove individual metal sheets 1li from a stack or pile 11 of the same and to forward the same away-from the pile. It is particularly adapted for use in unpiling the sheets by lifting successive top sheets from the pile in 'a vertical direction and thereafter feeding them one by one in a lateral direction to processing apparatus for further operations on the sheets.

The apparatus comprises an uprightV supporting frame structure 12 (FIGURES 1 to 4) on which there is mounted a horizontally disposed vertically reciprocable bed structure 13 lfor receiving a stack or pile of metal sheets 10 and an overhead magnetic conveyor 14, the latter being operable to lift successive sheets 1l) from the pile 11 and to deliver the same in single le relation at one end of the apparatus.

The supporting frame structure r12 comprises longi- Itudinally spaced end frames 15 and 16 which are connected at the bottom by parallel, laterally spaced, longitudinally extending side beams 17 and at the top by similar longitudinally extending side beams 18. The end frame structure 15 at the entry or receiving end of the apparatus comprises a -horizontal base plate 19 (FIG- URE 3), laterally spaced vertical side frame plates 20 Y and a connecting horizontal top plate 221. A relatively Vshort fixed platform 22 over which a pile of sheets is moved into the apparatus is arranged over the base plate 19 and comprises a plurality of rollers 23 and a supporting frame structure 24, the latter being secured between the side plates 20. At the inner edges of the side plates i vertically extending screw receiving housings 25 are lprovided which are channel shaped in horizontal cross Y section and which are arranged with their open sides facing inwardly toward each other.

The end frame structure 15 at the other end of the apparatus comprises a horizontal bottom plate 26, a pair of laterally spaced side plates 27 anda transversely and vertically extending inner cross plate 28 which connects ther inner edges of t-he vertical side'plates 27. Horizontally extending top plates 30 are supported on the upper edges of the side frame plates 27 by angle brackets 31. Vertically extending screw receiving housings 32 are provided at the inner edges of the vertical side plates which are channel shaped in horizontal cross section and which are arranged with their open sides facing inwardly towards each other in the same manner -as the screw housings25 in the end frame 15 at the other end of the apparatus.

The vertically movable bed structure 13 on which the pile 11 of sheets 10 is supported during the feeding or unpiling operation comprises a horizontally disposed frame 33 and a plurality of rollers 34 supported thereon. The frame 33 is of generally rectangular shape and comprises oppositely disposed parallel longitudinally extending side frame members 35 and an intermediate longitudinal supporting member 36 which is parallel to the side members 35 and which divides the frame into two longitudinally extending rectangular sections. The side frame members or rails 35 and the intermediate rail 36 are joined at the ends by cross brace members or plates 37 With appropriate intermediate cross brace members as required. The rollers 34 extend in transversely aligned and paired relation on the frame 33t, being rotatably supported in suitable bearing formations 39 which are mounted on the side rails 35 and the intermediate center rail 36 and which have upwardly opening slots forV receiving the ends of the roller carrying shafts 38.

The frame 33 is supported at its opposite ends by means of saddle members 40 (FIGURES 5, 6 and 8) extending transversely of the machine. Each of the saddle members 40 comprises an upwardly and inwardly facing angle member 41 having a cross bar 42 supported on its horizontally disposed bottom ange 43. The side rails 35 and the center rail 36 of the frame 33 are provided at opposite ends of the frame with longitudinally projecting, vertically extending bearing plates 44 each having on its bottom edge a downwardly opening recess or slot 45 (FIGURE 6) for engaging therein the cross bar 42 of the saddle 40. Each of the saddles 40 is provided at each end of the angle member 41 with a vertically extending end plate 46 (FIGURES 5 and 8) which has mounted on its outer face a pair of spaced, outwardly extending, vertical plates 47 which form a downwardly opening nut socket for engaging over a nut 48. The nut 48 is in the form of a truncated pyramid with upwardly facing curved bearing surfaces 49 on opposite faces thereof on which the lower edges of the vertical plates 47 are seated, the edges Y of the plates 47 having a curvature corresponding to that manner in its respective housing, being supported at its lower end by a bearing member 52 (FIGURE 5) and at its upper end by a bearing member 53. The screw 51 has a vertical extension member 54 at its upper end which is supported in bearing members 55 and 56 in a vertically disposed housing extension 57 which is mounted on the top of the end frame structure and forms a continuation of the housing 32, the housing 25 on the end frame 15 having a corresponding vertical extension 58.

The extension memberV S4 on each lifting screw 51 is provided on its upper end with a worm gear 59 and each of the Worm gears 59 is fin toothed engagement with a worm 60 on one of the two parallel operating or drive shafts 61 which extend longitudinally at opposite sides of the lapparatus.

The drive shafts 61 are supported in sui-table bearings at their opposite ends in the housing extensions 57 and 58 and intermediate the latter in longitudinally spaced bearing supports or brackets '62 which are mounted on the upper surfaces of the top side rails 18. Each of the shafts 61 is connected at the pile receiving end of the apparatus by a suitable coupling 63 to a gear reduction unit 64, a pair of the latter being mounted in laterally spaced relation on the top plate 21 of the end frame 15. The gear reduction units 64 are driven by a transversely extending connecting drive shaft 65 which carries a drive pulley 66 connected by a drive belt 67 with the pulley 68 on a drive motor 70 also mounted on the top frame plate 21. The drive shaft 65 is connected to the drive pulley 66 through an air operated clutch unit 71 and a brake unit 72, also air operated, is provided for quick stopping of the shaft 65, ythe brake unit 712 being mounted on an upstanding support bracket 72 on the frame plate 21.

The frame 33 of the bed member 13 is positioned somewhat higher at the entrance or pile receiving end than at the opposite end thereof so that when a pile of sheets 11 is rolled thereon it will move by gravity towards the opposite or sheet discharging end and a Iroller braking mechanism (FIGURES to 9) is provided on the bed 13 to control this gravitational movement of the pile of sheets 11. The braking arrangement comprises four rectangular frames 73 (FIGURES 6 to 8) which are positioned in horizontally disposed relation within the frame 33 adjacent the `discharge end of the apparatus. Each brake frame 73 is vertically movable in a `guideway formed by longitudinally spaced, vertically extending angle brackets 74 which are arranged on the side and center rails 35 and 36, respectively, of the frame 33 and which cooperate therewith to form vertical guideways in which the four corners of each frame 73 are received. Each of the brake frames 73 comprises three transversely extending longitudinally spaced U frames 75 (FIGURES 6 to 9) arranged with leg portions projecting upwardly between successive pairs of rollers 34, two of these U frames constituting the end members of the frame 73. The U frames 75 carry a cross bar 76 on the upper ends of their legs on which roller engaging braking plates or shoes 77 are mounted which have beveled side edges positioned to frictionally engage with the surfaces of the rollers 34 when the frame 73 is lowered by the mechanism which will be described. The brake shoe carrying U frames 75 are connected at their ends by longitudinally extending, laterally spaced channel shaped frame members 78 which are arranged rwith their open sides facing towards the outside edge of the apparatus and which constitute the side members of the frame 73. The side frame members 78 are apertured at 79 (FIGURES 7 and 9) to accommodate transversely extending operating shafts 80, each of which is mounted in suitable bearing sleeves 81 and SR2 in the bearing forming members 83 and 84, the latter being mounted in the side and center rails 35 and 36, respectively- 'I'he operating shafts 80 extend the full -width of the bed structure 13 and carry cam members 85 for engaging with each of the brake side frame members 78. The cam members 85 are keyed on each shaft 80 so that the track forming eccentric periphery 86 of each cam 85 is positioned between the vertically spaced upper and lower flanges 87 and 88 of the side frame members 7 8 whereby when the shafts 80 are rotated the brake frames 73 are raised and lowered. The shafts 80 each carry in tixed relation thereon two axially spaced operating arms 89 which have their free ends pivotally connected at 90 to longitudinally extending links 91, the latter being spaced transversely of the bed structure 13. One end of each link 91 is pivoted at 92 to the end of the piston 93 of an hydraulic cylinder or motor 94, the

spaced brackets 96 mounted on the cross frame member 37 at the discharge end of the bed 13. Each of the hydraulic motors 94 and its linkage for connecting the same to the shafts 80 is located intermediate the side frame members 78 of each of the end brake frames 73 and each motor 94 is connected to all four shafts 80, the motors being operated in synchronism to apply or release the brake shoes 77 as required.

'I'he magnetic conveyor assembly 14 (FIGURES 1, 2, 5 and 6) comprises a plurality of laterally spaced elongate magnetic rail units y100 which are mounted to extend lengthwise of the apparatus above the bed or table |13 and which are supported on longitudinally spaced cross beams 101 and 102. Each of the magnetic rail units 100 comprises a pair of traveling belts 103 mounted on end pulleys 104 and 105 secured on cross shafts 104 and 105', respectively. A series of electromagnets indicated at 106 are carried on the units 100 in longitudinally spaced relation along the lower run of the conveyor belts 103. These magnetic rail units 100 are preferably constructed in accordance with the disclosure in Patent No. 2,642,174, dated lune 16, 1953, to which reference is made for details not herein disclosed. The magnetic conveyor units 100 are driven by rotation of the end shaft 104 which is mounted at the opposite ends thereof in bearing formations 107 (FIGURE 4) projecting upwardly of the end frame plates 30 and has one end extended beyond the frame side plate 27 to receive a drive pulley 108 which is connected by a drive belt 109 with a power pulley 110 on a drive motor and gear reduction unit 111 supported on the base plate 26 of the end frame 16. The shaft 105 and vthe pulleys 1015 at the other end of the apparatus are idler members supporting the conveyor belts at that end of the units 100, the shaft 105 being suitably supported at its ends.

A delivery platform 1112 (FIGURES l, 2, 4 and 6) is arranged at the discharge end of the apparatus below the discharge end of the magnetic conveyor assembly 14 which comprises a plurality of longitudinally spaced transversely extending sectional rollers 113 supported on a frame structure 114 mounted between the side plates 27 of the end frame 16 immediately below the end of the conveyor 14 so as to receive and support thereon each successive sheet 10 as -it is advanced over the rollers 113 by the operation of the conveyor 14. The rollers 113 are mounted on shafts 115 and one of the shafts ,115 carries a sprocket 1-16 which is connected by means of a drive chain 117 with a sprocket 118 on the cross shaft 104', the chain 117 being =looped around idler sprockets 120 suitably supported below the roll shafts L15, At the other end the shafts 115 carry sprockets 121 which are connected in paired relation by drive chains I122 with the driven shaft 115 which carries the drive sprocket 116.

A sheet spreader 125 (FIGURES 6, 10 and l2) is provided at the top of the vertical plate 28 to spread the edges of the topmost sheets on the pile in an upward direction at the start of the lifting cycle. The spreader 125 comprises an angular housing or cover member P1126 which has a vertical leg or flange 127 secured to the vertical plate 28 with the surfaces of the flange and plate ush and a top leg or flange 128 extending horizontally in alignment with the delivery table members 122. The cover or housing member 126 is formed of stainless steel or other non-magnetic material and extends along the entire width of the machine. The vertical ange 127 of the housing 126 is provided at the top thereof with a series of transversely spaced rectangular apertures 130 and the horizontal flange 128 supports in depending relation thereon a plurality of magnetic spreader units 131 which are transversely spaced and aligned with certain of the apertures 130. Each of the spreader units 131 comprises two electromagnetic coils 132 on a pole member t133 which is secured at its upper end to a cross plate 134, the latter being suspended from latter being pivotally mounted at 95 in a pair 0f .laterally 75 the top Harige. 127 of cover '126 by bolts and spacers 135 of non-magnetic material. 'Ihe cross plate 134 has a forwardly extending upwardly slanted front edge portion 136 land forms an extension ofthe pole pieces 133 as well as a support for the units 131. The pole pieces 133 are connected at the bottom of the units by a cross member 137 of angular sectionwhich has a horizontal leg or llange 138 positioned beneath the units 131 and a vertical leg or flange I139 extending between Vthe coils 132 of the unitsv 131 and the vertical flange portion 127 of the cover member 126. A bar 140 is secured in an upwardly and forwardly angled position on the upper'edge of theflange 139 and a series of rectangular members 141 are secured in vertically extending relation on the upper edge thereof, one for each of the units 131. The members 141r and the poles 133 are aligned with the apertures 130 so that the members 1411 extend into the apertures 130, as illustrated in FIGURE 12, and the members 141 are vertically spaced from the top pole extension 136 so that when the coils 132 of the units 131 are energized, the path of the ilux extends across thegap provided between the pole extensions 141 and 136 with the result that when the top of the pile of sheets is brought to a point between the members 141 and 1136, the edges of the topmost sheets 'will be spread apart as illustrated in FIGURE 12, the separating occurring along the entire edge of the topmost sheet. The coils 132 (FIGURE Y15) of the separator units 131 are energized withrthe closing of switch S1 (FIGURES l5) and the application of power to the magnet coils in the conveyor 14 so that separation of .the leading edge of the top sheet from Athe next sheet in the pile -at the beginning of the lifting cycle is insured. l

A top-of-the-pile limit switch 142 (FIGURE 11) is mounted on the vertical end plate 28 below the separator device 125 and is provided Ywith an operating lever 1143 which is actuated by upward movement of the pile of sheets. The operating lever 143 is arranged in vertically extending relation on a mounting bracket 4144, the latter Vbeing supported in depending relation on the bottom face of the horizontal leg 128 of the separator cover member 126 and carrying at its lower end a bifurcated portion 146 having a pivot pin 148 on which the lever 143 is supported intermediate its top and bottom ends.

A The upper end of the lever 143 has a cam formingV portion 150 (FIGURES l() and lll) which-extends through one of the slots 130 in the vertical iange 127 of the separator 4cover 126. The lower end 151 of the switch of the pile, to stop the upward movement of the bed 13. An apparatus is provided at the discharge end of the machine for controlling Vthe height of the top sheet in the pile or the distance between the top sheet and the bottom face of the conveyor 14. This apparatus 154 (FIGURES l, 10, and 13) also serves to lift the leading edge of the top sheet toward the conveyor so as to insure Y that the leading edge of the sheet is properly positioned against the conveyor belts as the sheet begins its forward movement'on the Vconveyor 14. This apparatus insures that the sheets will be consistently picked up and sent forward even though the condition of the sheets varies.

The height control and sheet edge lifting apparatus 154 is supported on a channel 155 which is mounted on and extends across the top of the conveyor rail units 100. The apparatus comprises two solenoid units 156 and `157 which are identical in construction and operation, with one of the units 156 being arranged to actuate a switch -160 which controls the vertical movement of the pile supporting bed 13, as hereinafter described. Both solenoid units l156 and 157 are supported on the channel 155 in dependingY relation between the conveyor units Both of these units include vertically movable plungers which are adapted to rst simultaneously engage the top surface ofthe top sheetV as the pile is lifted by the upwardly moving bed 13 Vand which are then operated to magnetically grip and raise further the front edge of the topmost sheet of the pile when the bed 13 is stopped by operation of the switch 16 with the topmost sheet in the pile at a predetermined distance from the bottom of the conveyor'14 for which the apparatus is adjusted.

The solenoid unit 156 (FIGURE 13) comprises a plurality of electromagnetic coils 161, preferably three in number, which are arranged in vertically disposed relation on a brass tube 162 and venclosed in a tubular housing 163. The housing 163 has a top plate 164 and the coils 161 are secured in the housing by a bottom ring 165 fastened to the same by bolts or other suitable fastening elements. The brass tube 162 is secured at its upper end to a tubular guide section 166 which depends from the top plate 164 and has a bore 167 for accommodating the stem forming upper extension 168 of a vertically movable solenoid core or plunger member 170 which acts as a sheet lifting finger. The plunger member 170 is raised and lowered by energizing and de-energizing the coils 161 with the upper limit of its movement determined by the depth of the tubular guide 166, the bottom edge of which forms an abutment or limit stop for the top end of the plunger member 170. The member 170 carries-a plate 171 on its lower end which is secured by a bolt I172 extending through a washer 172'. A rubber bumperV ring 173 is secured on the bottom face of the plate 171 which has its lowerrnost surface in a plane spaced somewhat below the bottom face of the washer `and bolt head so as to-avoid damage to the sheet when the latter is raised intoV contact with the member 170. The housing '163 is suspended from the supporting channel by a pair of tube sections 174 which are secured in upstanding relation on the top plate' 164 and which are connected in threaded relation to the lower ends of a further pair of tube sections 175, with the latter extending through suitable apertures in the web of the channel 155 and secured thereto by lock nuts 176 so that the vertical position of the housing may be adjusted. The stem 168 Vof the plunger or finger 170 extends through the bore of the guideY member 166 and also through an aperture 177 in the channel 155.

'Ihe stem 16S of the plunger 170 of the solenoid unit 156 is provided with a device for operating the switch Vin response to predetermined upward and downward movement of the plunger 170. To this end the stem member 168 has an upper end portion 178 of reduced section which provides an external shoulder 180 for cooperation with an internal shoulder 181 formed in a sleeve 182 which is slidably supported on the upper end of the stem member 168, and which has an upper end portion withY a bore of reduced diameter at 183. The sleeve 182 is of substantial length and -is carried on the stem member 168 so that it is Vraised by upward move- Vment of the plunger V which exceeds the distance necessary to bring theV shoulders and 181 into engagement. A rubber washer 184 Vis provided on the plate 164 which limits the downward movement of the sleeve 182 whenY the plunger 170 is allowed to drop below a predetermined point upon ile-energizing the coils 161. The sleeve 178 has a section `185 at its upper end which is of smaller external diameter and which is adapted to receive the end of the operating lever 186 of the microswitch '160. Y

The control switch `160 (FIGURE 10) is fixed on a vertically movable carriage forming member 188 which is mounted in vertically slidable relation on a post 190 upstanding from a bracket plate 191 secured on the channel 155. The bracket plate 191 carries an upstanding post-like member 192 which has secured thereon a generally triangular shaped Yor segmental dial member between a pair of bracket ears 198 on the slidable carriage 188. The operating lever 194 is provided with a handle 199 at its outer end which rides on the curved outer edge 200 of the dial 193 and Iwhich may carry a latch mechanism (not shown) of a suitable kind for holding the lever 194 in any desired position. The lever 194 is provided with a pointer 201 for cooperation with a calibrated plate 202 on the dial supporting plate 193, so that the vertical position of the switch 161? may be adjusted by manually swinging the lever 194.

The switch 160 is operated, upon the arm 186 being tripped by the upward movement of the sleeve 182, to stop the upward movement of the pile supporting bed 13. The sheet lifting plunger 170 rests on the top sheet and is lifted by the latter as the bed 13 moves upwardly to a point which positions the sheet at the proper distance below the conveyor 14 for lifting by the magnets in the conveyor rail units 100, this distance being previously determined for the weight and thickness of the sheet and the vertical position of the switch 160 being adjusted by setting the lever 194 at the correct point. As the switch 160 is operated to stop the upward movement of the bed 13 the coils 161 are energized which results in further upward movement of the members 170 and also in the sheet being pulled by magnetic force against the bottom end of the members 170. The members 170 carry the edge of the sheet upwardly into engagement with the bottom of the conveyor and then continue a short distance so that the bottom end is pulled free of the sheet, the latter being in eiect stripped from the fingers 170` when it strikes the conveyor. When the sheet is lifted into contact with the bottom of the conveyor units 100 by the pull of the conveyor magnets which are energized at the same time as the coils 161 and the sheet begins to move laterally above the top of the pile by operation of the conveyor belts the coils 161 are deenergized and the plunger 170 is free to drop down and engage the neXt sheet as the top sheet moves out from under the bottom end of the plunger and the sleeve 182 drops with it. The switch 160 is operated, upon the arm 186 being tripped by downward movement of the sleeve 182, to restart the upward travel of the pile supporting bed 13.

Vertical movement of the pile supporting bed structure 13 and operation of the sheet pickup conveyor 14 are controlled automatically upon loading of a pile of sheets onto the bed 13 and adjusting the height control mechanism 154 for the thickness and weight of the sheets. The circuits for supplying current to the drive motor units 70 and 111 are shown in FIGURES 14 and 15 with the necessary switches, relays and other electrical control elements being indicated schematically, the A C. control circuits being shown in FIGURE 14 and the D.C. control circuit for supplying direct current to the magnet coils in the conveyor assembly 14 being shown in FIG- URE 15.

Referring rst to FIGURE 15, the magnet coils in the conveyor assembly are divided into groups or sections lengthwise of the apparatus and are connected with a D.C. current supply line through switch S1 as illustrated, the magnet coils for each section, numbered 1 to 7 in FIGURE 15, being indicated as connected to the contacts K1 to K7 of a main contactor or control relay which is indicated at MC. In FIGURE 14, A.C. current is supplied through switches S2 and S3 to the control circuits. The contactor coils for the main contactor MC which controls the current for energizing each section or group of magnets are indicated at KL1 to KL7 in FIGURE 14 and the main magnet contactor coil is indicated at MCL in one of three circuits which are controlled by a selector switch indicated at 230. This circuit includes a series of inducto switches which are spaced along the conveyor assembly 14 and which are indicated at C1 to C7. These switches are actuated by passage of the trailing end of each sheet 11 as it is advanced by the conveyor 14, with each switch being connected to and controlling the energizing and de-energizing of a group of the magnet coils. While the sheet is beneath each switch C1 to C7, the switch is closed and the magnet coils controlled by the same are energized to hold the sheet against the traveling conveyor belts. When the trailing end of the sheet has passed beneath the switch it automatically opens to de-energize the magnet coils. The main motor unit 111 is controlled by the manually operated switch indicated at 231 (FIGURE 14) with forward and reverse operation and normally drives the conveyor belts continuously when the switchV 231 is closed for operation of the apparatus. 'I'he motor unit 70 which drives the lift screws 51 is operated continuously in accordance with the position or setting of the selector switch 230 through a lift control 232 which is in a second circuit through the selector switch 230 and which controls the speed of the up or down movement of the bed 13 with the direction being according to the setting of the selector switch 230. The drive shaft 65 is connected and disconnected with the motor 70 through the clutch 71 and a quick stopping brake 72 is `associated with the drive shaft 65, both the clutch 71 and the brake 72 being air operated under the control of valves which are in turn operated by solenoids indicated at VC and VB (FIG- URE 14), respectively, in the lift control circuit. An upper limit safety or crash switch 233 (FIGURES 5 and 14) for a lift bed 13 is provided, preferably, adjacent the top of a lift screw 51 for operation by engagement of its operating arm with the nut 48 to insure that the bed 13 does not rise beyond a predetermined elevation. A similar lower limit switch 234 is provided at the base of the lift screw 51 to stop the downward movement of the bed at a predetermined fixed point. The switches 233 and 234 are connected into the lift control circuit in FIGURE 14 along with the relays XA and ZB, the relay XA having a normally open contact XAa in the elevating circuit for the lift motor. A top of the bed limit switch 235 is adjustably mounted on the apparatus adjacent the bed so that its operating arm will be engaged by a moving part of the bed 13 when the bed reaches a predetermined height so as to initiate the return of the bed to the lowered position for a new pile of sheets. This switch has two contacts indicated at 235a and 235b in the lift circuit and the magnet control circuit which are normally closed and which are opened by the lift bed when the bed reaches the height at which the last sheet is removed. An inducto switch 236 (FIGURES 1 and 2) is positioned at the leading end of the conveyor 14 which serves as the main control for automatic operation of the apparatus. The main control switch 236 has two contacts 23611 and 236b which are normally closed and open, respectively, and which are in the magnet control circuit along with the relays ZL and TL, the latter having normally closed contacts T1 to T7 in the magnet control circuit. The top of the pile limit switch 142 (FIGURES 11 and 14), which is normally closed and which is opened when the actuating lever 143 is engaged by the top of the pile, is in the bed elevating circuit with the pile height control switch and the main control inducto switch 236. The pile height control switch 160 is opened by upward movement of the sheet lifting plungers i and closed by the downward movement of the sheet lifting plunger 170 to cause the bed raising mechanism to operate as the sheets are removed from the top of the pile and to stop the upward movement of the latter at a predetermined distance beneath the lower run of the conveyor 14. The switch 160 is connected to the relay ZL, the latter having two contacts ZLa and ZLb which are normally closed `and open, respectively, and which are in the circuit with the main magnet contactor coil MCL. Current is supplied to the solenoid V3 (FIGURE 14) which controls the roll brake mechanism on the bed 13y from 11 the line through a spring loaded manually operated switch 238.

In operating the Vapparatus the circuit 'breaker switches S1, S2 and S3 'are closed and the selector switch 230 is set at the down position. The relay ZB is energized and its normally open contacts ZBl and ZBZ close which results indownward movement of the lift bed 13 until it reaches thelower limit switch 234, the latter deenergizing the relay ZB which opens contacts ZBl and ZB2 and stops the downV movement of the lift bed through operation of the solenoids VC and VB, the latter disengaging the clutch 71 and applying brake 72. The pile is then rolled onto the lift bed 13 and moves by gravity toward the discharge end of the apparatus. The horizontal positioning of the pile is controlled by the roll brakes through the hand switch 238. When the pile is in the proper horizontal position the conveyor y14 is started by setting switch 231 at forward and the selector switch 230 is manually set Aat up position. The relay ZL is energized and its normally open contact ZLa is closed which closes the circuitoperating the clutch and brake valves through solenoids VC and VB, the relay XA being energized and closing its Vnormally open contact XAa and the lift bed 13 moves upwardly until the top of the pile engages with and raises the lift linger 170 la sufficient distance to operate the switch 166; The switch 166 is opened by the upward movement of the actuator sleeve and relay ZL is de-energized which opens contact ZLa and stops movement of lift bed A13. The coils 161 are energized to lift the fingers 170 to their uppermost lim-it and carry the leading edge of the sheet up with them. The top sheet is lifted along its entire length by the conveyor magnets 166 since current is supplied to energize all the magnet coils above the top of the pile simultaneously through the normally closed Y v contacts T1 to T7 of the relay TL. The upward move- I 'C1, C2 etc. and each switch then opens to de-energize the magnetsV of the section which each switch controls,

thereby avoiding pick up of the next sheet in the pile until the trailing edge of the sheet is clear of the pile. When the sheet moves forward of the pile the leading end of the sheet moves under the inducto switch 236 which closes the contact 23611 and energizes the relay TL opening the normally closed contacts T1 to T7 so that when the inducto switches C1 to C7 are openedY by .passage of the trailing end of the sheet no current is supplied to them-aguets controlled by the respective Switchers. When the contact 236b closes' the normally closed contact 23611 opens de-energizing relay ZL and the mechanism for elevating the bed 13 cannot operate until the sheet clears the conveyor and the trailing edge passes the inducto switch 236. Each successive inducto switch C1 to C7 opens as the trailing edge of the sheet passes itand the magnets controlled by it are de-energized. The coils 61 are de-energized when the conveyor magnets are deenergized by theV operation of the inducto switch 236 and when the sheet advances past the lifter ngers 170, the latter are freed to drop onto the next sheet in the pile which closes the sw-itch l160 and starts the bed 13 upwardly and the action is repeated. When the last sheet is removed the limitV switch 2135 is actuated by the bed and operates to open the contact 235a, releasing the clutch and applying the 'brake to stop the movement of the bed i3. VThe operator then moves the selector switch 230 to down position and the bed 13 is lowered to receive a new pile. Y

VThe sheet edge lifting iingers 170 and the associated switch operating mechanism provide a means for the operator to vary the pile level to suit the thickness of the material beingrhandled. The i'ingers 170l also operate to provide an extra pull or pull and break action on the top sheet so that there is no lag in pickingV up the top sheet and the feeding operation is constant.V The rubber ring :173 is madesuiiciently thick to protrude below the bottom of the metal core or finger member `170 so that no damage will be caused when the sheet strikes the end of the member and also so that the pull on the sheet will be less than the pull on the core member when the coils 161 are energized. 'This avoids any lag in the raising of the iingers which could occur if the pull on the core were less than the pull on the sheet. It also avoids any tendency of the fingers to lift the edge of more than `a single sheet. The coils 161 are de-energized as the bed rises and the core or linger assembly 17), 171, 172, y173 is down. The bed 13 will rise until the top sheet lifts the finger assembly high enough to `actuate the switch thereby stopping the bed. At this time the coils 161 and the conveyor magnet coils are energized and a small pull is exerted on the edge of the sheet as the coils I161 raise the core or linger members 179 so that the edge of the sheet is raised and broken from the rest of the pile. The iingers move upwardly due to the pull of the coils 161 until they are pulled all the way into the coils when the rubber ring 173 of each assembly will be clear of the sheet, the pull on the fingers 170 being greater than the pull on the sheet by the fingers, and the sheet being stopped by engagement with the bottom of the conveyor 14. This permits the sheet to be moved forward by the conveyor belts without interference from the lingers 170, the latter being allowed to drop to the down position by de-energizing the coils y161 which` occurs through operation of switch 236 as the' sheet passes out of the piler.

Preferably, inducto switches of the type described are employed in connect-ion with the automatic control of the operating mechanism, but it will be understood that any equivalent switching mechanism which can be actuated by movement of the sheets such as an electric eye switch, may be employed.

In the preferred for-m of the `apparatus as illustrated, vertically disposed power driven screws 51 are employed to raise and lower the pile supporting bed 13. However, other mechanism could be provided for vertically moving the bed .13, such as, traveling chains or hydraulic apparatus which would, of course, be connected to the bed frame in a suitable manner and provided with suitable controls for electrical operation.

With the apparatus illustrated full power on the magnets is normally employed and the distance of the topmost sheet from the bottom of the conveyor magnets is preset so that the topmost sheet only is attracted by the magnets. vIf desired, the distance from the top of the pile to the bottom of the magnets may be fixed and the voltage on the magnets adjusted by the operator so as to accomplish the lifting ofthe topmost sheet.

While specific materials and particular details of construction have been referred to in describing the illustrated embodiment of the invention, it will be understood that other materials and equivalent details of. construction may be resorted to within the spirit of the invention.

I claim: Y

l. In an apparatus for handling metal sheets having an upright supporting structure, and an overhead magnetic conveyor, a vertically movable pile supporting bed mounted beneath said conveyor, said bed comprising a rectangular frame, a series of rollers mounted for free rotation in said bed frame, a brake mechanism for said rollers comprising a brake frame mounted in vertical sliding relation on said bed frame, support members on said brake frame which extend upwardly between pairs of said rollers, elongate braking plates on said support members arranged below the pile engaging'p'eripheral portions of said rollers with opposite edges adapted to be engaged with thesurfaces of adjacent rollers upon downward movement of said brake frame relative to said bed frame, and power operated means to raise and lower said brake frame.

2. In an apparatus for handling metal sheets having an upright supporting structure, and an overhead conveyor, a vertically movable supporting bed mounted beneath said conveyor, said bed comprising a rectangular frame, a series of rollers mounted for free rotation in said bed frame and providing a supporting surface for a pile of sheets, a brake mechanism for said rollers comprising a brake frame mounted for vertical movement relative to said bed frame, roller engaging members on said brake frame which extend between pairs of said rollers, below the pile engaging peripheral portions of said rollers with opposite edges adapted to be engaged with the surfaces of adjacent rollers upon downward movement of said brake frame relative to said bed frame, and means to raise and lower said brake frame.

3. In an apparatus for handling metal sheets having an upright main supporting structure, and an overhead sheet -lifting and advancing conveyor, a vertically movable sheet supporting structure mounted beneath said conveyor, said sheet supporting structure comprising a rectangular frame, a series of rollers mounted for free rotation in said frame and providing a generally horizontal surface for receiving a pile of the metal sheets, a brake mechanism for said rollers comprising a brake frame, guide means for mounting said brake `frame in vertical sliding relation on said rectangular frame, elongate braking plates carried on said brake frame below the pile engaging portions of said rollers with opposite edges thereof adapted to be engaged with the surfaces of adjacent rollers upon predetermined movement of said brake frame relative to said rectangular frame and power operated means to raise and lower said brake frame.

4. In an apparatus as recited in claim 3, and said power operated means comprising an hydraulic motor mounted on said rectangular `frame, a linkage connecting said motor to a cross shaft mounted on said rectangular frame, and cam means on said cross shaft engaging with said brake frame for raising and lowering said brake frame upon rotation of said cross shaft by operation of said motor.

5. ln an apparatus for handling metal sheets having an upright supporting structure, and an overhead sheet removing conveyor, a vertically movable pile supporting bed mounted beneath said conveyor, said bed comprising a rectangular frame, a series of rollers mounted for free rotation in said bed frame, and means vfor supporting said bed frame in tilted relation so that a pile of sheets will move by gravity across said bed frame, a brake mechanism for said rollers comprising an elongate braking plate arranged between said rollers and below the pile engaging peripheral portions thereof with opposite edges adapted to be engaged with the surfaces of adjacent rollers upon vertical movement thereof, means to support said braking plate for vertical movement and power operated means to raise and lower said braking plate supporting means.

6. Apparatus for handling metal sheets comprising a supporting structure, a bed mounted on said supporting structure and having means thereon for receiving a pile of metal sheets, vertical lift members connected to said bed, power means to operate said lift members for raising and lowering said bed, a magnetic conveyor mounted in generally horizontal relation above said bed, means to operate said magnetic conveyor to lift successive top sheets from the pile on said bed by magnetic force applied along the entire length of the sheet and to advance each sheet laterally while it `is suspended above the top of the pile for delivery therefrom, and means actuated by movement of successive sheets for controlling the application of the magnetic force to progressively cut olf the same at the trailing end of each successive sheet as it is advanced across the pile and switch means for controlling the operation of the power means for said lift members Iwhich switch means is actuated in accordance `with the height of the pile of sheets on said bed whereby 14 to maintain the top of the pile on the bed at a predetermined elevation below the magnetic conveyor.

7. In an apparatus `for unpiling metal sheets, a vertically movable platform on which a pile of sheets is supported, a magnetic conveyor mounted above the platform, said conveyor having non-metallic sheet advancing belts and cooperating magnets, the lower run of the belts being spaced in a generally horizontal plane above the top of the pile of sheets so that the belts are adapted to advance each sheet laterally of the pile while it is held against the same by magnetic force, means for energizing the magnets to lift each successive top sheet along its entire length and advance the same Ilaterally across the pile without any metallic contact until it is clear of the pile, means to progressively de-energize the magnets as the trailing end of each sheet passes the same `in its advance over the pile, and means actuated by vertical movement of the top of the pile of sheets to elevate the pile supporting platform and maintain the top of the pile of sheets at a predetermined elevation below the lower run of the conveyor belts.

8. A method of removing metal sheets from a pile thereof which comprises supporting the pile of sheets on a vertically movable platform and controlling the vertical movement of the pile to maintain the top thereof at a predetermined elevation, removing successive top sheets from the pile by lifting the same with magnetic force and moving each successive sheet laterally away from the pile while said sheet-is suspended by the magnetic force applied thereto and controlling the application of the magnetic force to the sheet to progressively cut olf the magnetic force at the trailing end of the sheet as the sheet moves laterally of the pile, thereby preventing the lifting of the next succeeding top sheet from the pile while the preceding sheet is suspended above the pile.

9. A method of unpiling metal sheets which comprises arranging a pile of the sheets on a movable platform, vertically moving the platform to maintain the top of the pile of sheets at a predetermined elevation, lifting successive sheets above the top of the pile by application of magnetic force along the length of the sheet and advancing each successive sheet laterally of the pile while it is held suspended by magnetic force and free of metallic contact, and progressively cutting olf the magnetic force which is eiective at the trailing end of the sheet thereby to prevent the lifting o-f the next succeeding sheet until the preceding sheet is clear of the top of the pile.

10. A method of removing metal sheets from a pile thereof which comprises supporting the pile of sheets on a vertically movable platform and controlling the vertical movement of the pile to maintain the top thereof at a predetermined elevation, removing successive top sheets from the pile by lifting the `same with magnetic force and moving each successive sheet laterally away from the pile while said sheet is suspended by the magnetic force applied thereto and controlling the application of the magnetic force to the sheet to progressively cut olf the magnetic force as the sheet moves laterally of the pile thereby preventing the lifting of the next succeeding top sheet from the pile while the preceding sheet is suspended with portions thereof above the pile.

ll. A method of unpiling metal sheets which comprises arranging a plurality of the sheets in piled relation so that tthe topmost sheet may be moved vertically, bodily lifting successive top sheets from the pile by applying magnetic force above the pile and 'along the entire length of the sheet, conveying each successive sheet laterally of the pile while it is suspended by magnetic force and holding the sheet clear of any metallic contact, vertically moving the pile and maintaining the top of the pile at a predetermined elevation relative to the magnetic force, progressively cutting olf the magnetic force which is effective at the trailing end of the sheet as each sheet is moved laterally above the top of the pile thereby to prevent the lifting of the next succeeding sheet and releasing each sheet when it is clear of the pile. t

12'. Inan apparatus for unpi'ling metal sheets, a vertically movable platformY on which a pile of sheets is supported, a magnetic rail conveyor mounted above the platform, said conveyor havinglnon-rnetallic sheet engaging traveling belts and cooperating magnets, the lower run of the belts being spaced in a generally horizontal plane above the top of the pile of sheets and arranged so that the belts advance each successive top sheet laterally of the pile when it is pulled against the belts by the magnets, means for controlling the magnets to lift each successive top sheet along its entire length and :hold the same against the belts for lateral movement'without any metallic contact until it is clear of the pile, power means for moving the pile supporting platform vertically to bring the topmost sheet of the pile to a predetermined elevation below the lower run of the conveyor belts, a solenoid unit mounted adjacent the Vleading edge of the topmost sheet in the pile and having a vertically movable plunger arranged to engage at the bottom end with the top sheet of the pile, means to control the energizing of the solenoid unit so as to exert an upward pull on the leading edge portion of the top sheet suicient to lift said edge portion of the top sheet toward the conveyor belts and means operatively connected with said plunger for controlling the power means for the pile supporting bed so as to raise the bed in response to movement of said plunger.

13. In an apparatus for unpiling metal sheets, averlticallly movable platformen which a pile of sheets is supporteda magnetic conveyor mounted above the platform, said conveyor having a non-metallic sheet engaging A traveling belt and cooperating magnets, the lower run of the belt-being spaced in a generally horizontal plane above the top of the pile of sheets and arranged so that I the belt will advance each successive top sheet laterally of the pile when it is pulled against the belt by the magnets, means for controlling 'the magnets to lift each successive top sheet and thereafter to hold the same against the belts for 'lateral movement untilit is clear of the pile, power means for moving the pile supporting platform vertically to bring the -topmostY sheet of the pile to a predetermined elevation below the lower run Vof 'the conveyor belt, one ormore solenoid units mounted above the leading edge of the topmost sheet in the pile and each having a plunger disposed to move in a vertical path with the bottom end in position to engage with the top sheet of the pile when the latter is raised to a predetermined position, means to control the energizingV of the Vsolenoid units so as to exert an upward pull on the leading edge portion of the top sheet suliicient to lift said edge portion of the `top sheet toward the conveyor and a switch actuated by movement of atsolenoid plunger for controlling the power means for the pile supporting bed so as to raise the bed a predetermined distance upon removal of each successive sheet from the pile. j

14. In an apparatus for unpiling metal sheets, a vertically movable platform on which a pile of sheets is supported, a magnetic rail conveyor mounted above the platform, said conveyor having `a non-metallic sheet engaging travelingV belt and cooperating mag-nets,V the lower run of the belt being'spaced in a generally horizontal plane above the 4top of the pile of sheets and arranged Vso that each successive top sheet will be moved laterally of the pile when it is pulled against the belt'by the magnets, means for energizing the magnets to lift each successive top sheet along its entire length and to hold the same against y.the belt, power means for moving the pile supporting platform vertically to bring the topmost sheet of the pile to a predetermined position below the lower run of the conveyor, solenoid units mounted above the lead- Aing edge portions of the topmost sheet in the pile, each of said solenoid units having a vertically movable plunger arranged to engage at the bottom end with the top sheet of the pile when the solenoid is oie-energized andthe pile is at a predetermined elevation, means to control the energizing of the solenoid unit so that the plunger will engage with and exert an upward pull on the leading edge portion of the top sheet suliicient Ito lift said edge portion of the top sheet toward the bottom run of the conveyor, and means operative in response to movement of said plunger for controlling the power means for moving the pile supporting bed.

15. An apparatus for unpiling metal sheets comprising a supporting frame, an overhead magnetic conveyor on the supporting frame, said conveyor having magnets spaced along the same and traveling members beneath the magnets, a pile supporting platform disposed beneath the conveyor for receiving thereon a plurality of the sheets in vertically aligned pile forming relation, means for raising and lowering the platform, means to energize the conveyor magnets to lift successive sheets from the top of the pile and hold the same against the traveling members for advancing the same away from the pile, an adjustable gauge and control mechanism responsive to the upward movement of each top sheet in the pile for operating the platform raising means so that each successive ytop sheet is positioned at a predetermined distance below the conveyor whereby the sheet may be picked up by the magnets in the conveyor and removed from above the pile by the traveling members without disturbing the next succeeding sheet in the pile, and control means for succes'sively de-energizing fthe magnets at the trailing end of the sheet as thetraveling members move the sheet across the top of the pile so as to avoid picking up the next sheet in the pile as it is uncovered by lateral movement of the top sheet.V

16. Apparatus for handling metal sheets comprising a supporting structure, a rectangular bed mounted on said supporting structure and having rollers thereon for receiving a pile of metal sheets, vertical lift members connectedrto said bed, power means to operate said lift members for raising and lowering said bed, a conveyor having continuously traveling belts and electromagnets above the lower run of said belts mounted in generally horizontal relation above said bed and control means for energizing and tie-energizing the conveyor magnets so as to pick up successive sheets from the pile on said bed by magnetic force and advance said sheets across the top of the pile for delivery therefrom,tsaid control means being actuatedby movement of successive sheets for `de-energizing the conveyor magnets Vto progressively cut otf the magnetic force at the trailing end of each successive sheet as it is advanced across the pile.

17. Apparatus for handling metaltsheets comprising an upright supporting frame,v a rectangular bed disposed in horizontal relation on said frame for receiving a pile of metal sheets, vertically disposed lift screws connected to said bed, power means to rotate said screws for raising and lowering said bed, a conveyor having longitudinally spaced magnets positioned above the lower run of traveling sheet supporting members which conveyor is mounted onrsaid supporting frame in generally horizontal relation above said bed, means to energize said conveyor magnets so as to pick up successive sheets from the pile on said bed by magnetic `attraction and advance said sheets across the top of the pile for delivery therefrom, and electrical controls for operating said power means and for energizing and de-energizing said conveyor magnets including a first switch actuated 'by vertical movement of the top sheet on the pile whereby to control the vertical movement of said bed andmaintain automatically the height of the pile at a predetermined elevation and a second switch actuated by forward movement of a sheet to automatically energize the conveyor magnets for lifting successive sheets and advancing the same laterally of the pile and a series of switches actuated by passage of a sheet to de-energize the magnets successively as the trailing end of each sheet exposes the next sheet in the pile to the force of the magnets.

18. Apparatus as recited in claim 17 and said electrical controls including a switch which is actuated upon movement of said bed to a predetermined position where the supply of sheets is exhausted and which operates said power means to lower the bed for receiving a new pile of sheets.

19. In an apparatus as recited in claim 13 and each of said plungers having a pad member of non-magnetic material on the bottom end thereof which is of suicient thickness to slightly space the sheet it engages with from the bottom end of the plunger.

20. Apparatus for handling metal sheets comprising a supporting frame structure, a horizontally disposed vertically movable lift bed mounted on said supporting structure for receiving a pile of metal sheets thereon, power operated litt members for raising and lowering said bed, a magnetic conveyor mounted on said supporting structure in generally horizontal relation above said bed, means to operate said magnetic conveyor to lift successive top sheets from the pile on said bed by magnetic force and to advance each sheet laterally of the pile while it is suspended above the top thereof for delivery therefrom, a non-magnetic housing extending laterally on said supporting frame immediately beneath the delivery end of said conveyor and having a vertically disposed face extending along one side of the pile supporting bed with laterally spaced, vertically extending apertures which terminate adjacent the top of said housing, a plurality of laterally spaced magnetic sheet edge separators mounted in said housing, each of said separators comprising a vertically disposed core member having magnetic coils mounted thereon and upper and lower extension members on opposite ends of said core member, said separators being mounted with the uppermost extension member terminating at the top of an aperture in the vertical face of said housing and the lowermost extension member terminating in vertical spaced relation to the uppermost extension member, means to control the operation of said lift members and said bed so as to position the edges of the top sheets in a pile on said bed in the area between the vertically spaced core extension members of said edge separators, and means to control the current in said separator coils so as to cause the leading edges of the topmost sheets in the pile to spread vertically when the conveyor is operated to lift the topmost sheet from the pile whereby the edge of the topmost sheet is raised vertically above the top of said housing as it is lifted by said conveyor and thereafter advanced by said conveyor across the top of said housing.

21. Apparatus for handling metal sheets comprising a supporting frame structure, a horizontally disposed vertically movable bed mounted on said supporting structure for receiving a pile of metal sheets thereon, power operated lift members for raising and lowering said bed, a magnetic conveyor mounted on said supporting structure in generally horizontal relation above said bed, means to operate said magnetic conveyor to lift successive top sheets from the pile on said bed by magnetic force and to advance successive sheets laterally while suspended above the top of the pile for delivery therefrom, a non-magnetic housing extending laterally on said supporting frame immediately beneath the delivery end of said conveyor and having a vertically disposed apertured `face extending along one side of the pile supporting bed, a plurality of laterally spaced magnetic sheet edge separators mounted in said housing, each of said separators comprising a vertically disposed core member having magnetic coils mounted thereon and upper and lower extension members on opposite ends of said core member, the uppermost core extension member terminating adjacent the top of an aperture in the vertical face of said housing and adjacent the top of said housing, the lowermost extension member terminating in vertical spaced relation to the uppermost extension member, means to control the operation of said lift members and said bed so as to position the edges of the top sheets in a pile on said bed in the area between the vertically spaced core extension members of said edge separators, and means to 'control the current in said separator coils so as to cause the leading edges of the topmost sheets in the pile to spread vertically when the conveyor is operated to lift the topmost sheet from the pile whereby the edge of the topmost sheet is raised vertically toward the top of said housing as the sheet is lifted by said conveyor and thereafter advanced above said housing.

References Cited in the tile of this patent UNITED STATES PATENTS 875,837 McIntyre Jan. 7, 1908 1,716,602 Ross .Tune l1, 1929 1,809,076 Shinn et al. June 9, 1931 2,541,985 Chatterton Feb. 20, 1951 2,650,092 Wall Aug. 25, 1953 2,650,824 Fowler Sept. l, 1953 2,766,043 Buccicone Oct. 9, 1956 2,855,197 Nash Oct. 7, 1958 2,895,733 Powers July 21, 1959

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