US1870337A - Sheet feeding apparatus - Google Patents

Description

E. S. LINCOLN SHEET FEEDING APPARATUS Filed June 11,- 1930 5 Sheets-Sheet l 3nventor W MVM (Ittomegl Aug. 9, 1932. E. s. LINCOLN 3 3 SHEET FEEDING APPARATUS Filed June 11, 1950 5 Sheets-Sheet 2 T n S3 3nnentor C'a/W MOW/4mm Aug, 9, 1932.

E. s. LINCOLN SHEET FEEDING- APPARATUS Filed June 5 Sheets-Sheet 5 Ihw entor (Ittomeg 1932- E. s. LINCQLN 1,870,337

SHEET FEEDING APPARATUS Filed June 11, 1950 s Sheets-Shet 4 Snnentor attorney,

Aug. 9, 1932. E. s. LINCOLN SHEET FEEDING APPARATUS 5 Sheets-Sheet 5 Filed June 11, 1930 Snvcntor Qttornegs Patented Aug. 9, 1932 unrrsn sures PATENT OFFICE nnwin s. LINCOLN, or scARsnALn Nnw YORK, ASSIGNOR T DEXTER FOLDER oom- PANY, on NEW YORK, N. Y., A CORPORATION on NEW YORK SHEET FEEDING APPARATUS Application filed June 11, 1930. Serial No. 460,528,

This invention relates to'means for sepmating and lifting sheets one by one from a stack of such sheets, and more particularly to means for separating and lifting sheets {of magnetic material.

Heretofore in apparatus of this character, much difiiculty has been experienced in preventingthe picking up of more than one sheet at a time. Due to the fact that metal lic sheets, of tin, for example, tend to stick together until air has been admitted between them, the second sheet tends to be picked up with the top sheet. Moreover the magnetic lifting flux tends to penetrate the top sheet into the second sheet and to liftjthe latter also,"'particularly where the sheets are stuck together. However, when it is attempted to control the-magnetic flux to prevent such penetration, by cutting down the strength of the magnet or by concentrating the flux in a small sheet area, it is generally found that the lifting effort is too small.

One of the objects of this invention is to provide novel sheetseparating means which will reliably separate sheets of'magnetic ma terial from a stack at a rapid rate. Another object is to provide novel magnetic lifting means whereby the flux does not penetrate through the top sheet to the second sheet, but yet sufficient lifting effort is obtained.

A. further object is to provide a novel lifting magnet which provides a lifting flux of low density distributed overa large sheet area.

'A still further object is to provide novel operating means for liftingmagnets.

. Other objects will appear more fully hereinafter as the description of the invention proceeds.

Several embodiments of theinvention have been illustrated in theaccompanying drawings, but it is to be expressly understood that such drawings are forpurposes of illustration only and are not to. be construed as a Fig. 1 is a side elevation of an apparatus 7 embodying the invention;

Fig. 7 is a section through the solenoid adapted to operate the magnetic lifters;

Fig. 8 is a side elevation of another embodiment of the invention; i Fig. 9 is a top planview of Fig.8; and Fig. 10 is a wiring diagram for the embodiment shown in Fig. 9. i

While the separating and feeding mechanism constituting the invention is broadly adapted for and may be employed'in the separation and feeding of sheets for any purpose, the drawings show the invention embodied in an apparatus for separating and feeding sheets of magnetic material, such as tin, from a stack to a feed or conveying'table. Accordingly, a supporting frame 1 of any suitable construction and material, whereby the separating and feeding mechanism is supported, is associated with a feed table 2 of any suitable type that is provided with conveying rollers 3. A stack or pile of sheets' l, in this instance of tin, is supported by a suitable table 5 preferably provided with suitable side register devices 6. The table 5 is carried by an elevating mechanism of any suitable type, and inthe form shown, rests on flights 7 secured to elevator chains 8, the latter passing over and being driven by sprocket wheels 9 mountedon a pair of shafts 10, one at each side of the frame.

For the purpose of rotating said sprocket wheels to drive the elevator chains, each of the shafts 10 preferably carriesa worm gear 11 meshing with a worm 12, the latter being mounted on a shaft 13 that rotates in suitable bearings formed on the frame'l. Any suitable means may be employed to rotate the shaft13 to elevate the table 5, and in the form shown, an electric motor 1% which is suitably mounted on a bracket constituting a part of the frame of the feed table 2 carries a pinion 16 on its shaft meshing with an idler 17 which in turn drives a pinion 18 on the shaft 13. Any suitable means, either manually or automatically operated, may be provided to control the circuit of the motor 14 whereby the top sheets of the stack are elevated tothe desired height at which they are maintained by means of a ratchet 19 on the shaft 13 with which cooperates a pawl 20 that is carried by a shaft 21 mounted in theframe 1 and provided on its outer end. with a handle 22. It is to be expressly understood, however, that the above described pile elevating mechanism is shown for purposes of illustration only and constitutes no part per se of the present invention.

Suitable means are provided for separating and lifting the rear corners or rear edge of the top sheet from the top of the pile andv for thereafter feeding the sheet off the pile.- 1n the form shown, where sheets of: magnetic material are to be fed, the separating and lifting means preferably comprises magnetic lifters, preferably one for each rear corner of the sheet, said lifters being preferably of a type hereinafter described that is particularly adapted to prevent the penetration of the lifting flux through the top sheet; Said lifting units are each designated as a whole by 23 and suitable means are provided. for lowering the lifters into contact with the top sheet of the stack and for raising the same to lift the top sheet. In the form shown, each of the magnetic lifters 23 is lowered and raised by means of a rockshaft 24 rotating in brackets 25 secured to the frame'l and. carrying-rock arms 26 on which the magnets are adjustably mounted by means of posts 27 through which the arms 26 pass. Preferably the shafts 24 are oscillated by means of a solenoid 28 that is'mounted by means of straps 29 and arms 30, from rods 31 that are supported in the brackets 25 and carry a cross arm 32 to which arms are attached. The operating solenoid 28- is shown in detail in Fig 7, and comprises a pair of operating coils33, separated by a non-magnetic plate 3 1, and pair of plungers 35, one for each coil 33. When the coils33 are energized, plungers 35 are drawn into the coils toward the center, and preferably have a tight sliding fit so that they are cushioned to prevent impact against plate 34. The ends of plungers .35 may be bifurcated at 36 as shown in Fig.1 and pins 37 e7;- tend through said bifurcations and through slots in the ends of arms 38 that are secured to the rockshafts 24. When the coils 33 are energized and the plungers-35 are pulled into the coils, shafts 2d are rocks-(l by the arms 38 to raise the lifting units 23 so as to pick up the rear corners of the top sheet, as clearly shown in Figs. 1 and 2. When the solenoids are deenergized, the weight of the lifting units is suflicient to cause them to fall back into contact with the next sheet, or if desired suitable resilient means or the like may be employed to accomplish this end. d

When the rear corners of the sheet have been lifted as above described, the sheet is fed forwardly off the pile by means which as shown comprise a pair of reciprocating fingers 39'whichengage the lifted rear corners and push the sheet forwardly until the forward edge thereof passes over a curved guide plate 10' and into engagement between rotating feed rollers 1-1 and 12. The fingers 39 may be reciprocated in any suitable manner, and, as shown, are secured to horizontal rods 413 which extend slidably through suitable supporting members 44: and d5 at the front and rear of the apparatus respectively. A V-shaped bracket 46, the arms of which are rigidly connected to the rods 43, is carried by the plunger 47 of a solenoid 18, the latter being supported by straps 49 and brackets 50 from the frame 1. Resilient means are provided for normally maintainingthe fingers 39, rods 43 and plunger 17 in retracted position, said'means as shown comprising coil springs 51 surrounding each of the rods 43 and interposed between the bracket 46 and the supporting member 44. lVh'en the solenoid 1-8 isenergized, the plunger 47 is pulled forwardly against the tension of springs 51, whereby fingers 39 move forwardly into engagement with the elevated rear corners of the sheet and push it forwardly until it is engaged by the feed rollers 41, 42 and fed off the pile to the conveying rollers 3' of the feed table 2. Any suitable means may be em ployed for rotating said feed rollers, which means may comprise a motor 52having a pinion 53 on its shaft that meshes with an idler 5 1 which in turn engages one of a pair of inopposite. polarities so that the flux is uniformly distributed over the area coveredby the unit. By this means the lifting flux which is necessary to lift the corner of the sheet is distributed over a'substantial area of the sheet so that the density of the flux passing through any one portion of the sheetis kept low, with the result that sufficient lifting effort is obtained without penetration of the magnetic flux through the top-sheet.

Preferably, each ofthe magnet coils 58 adjustably carried by itssupporting plate 57 in order to allow for any unevenness of the sheet surface,,and accordingly. each'coil 58' i is mounted on a hollow sleeve 59 of magnetic In some instances it is desirable to provide means for positively holding down the portions of the sheet'adjacent the corners which are lifted by the lifting units 23, so that the sheet is positively flexed to effect the initial separation thereof from the next adjacent sheet. To this end, holding down magnets 63 may be employed, said magnets being suitably supported from the frame bymeans of rods 63. Said. holding down magnets are preferably of a type described and claimed in a c'o-pending application and are adapted to hold down the sheet while it is initially flexed'and thereafter to lift the held down portion of the-sheet from the stack. Referring to Fig. 1, each magnet 63 comprises two operating coils 64 and 65 that are separated by'a plate 66 of suitable non-magnetic, material such as brass. ,A double acting plunger is provided for the coil, comprising two magnetic; core portions. 67 and 68 connected by a rod 69' preferably of non-magneticmaterial,*said rod passing freely through an opening formed in the plate 66. When'the upper coil 65 is energized, core 68 is pulled into" the coil so that core 67 is positively heldidowna ainst thesheet. When'coil 65" is deenerg zed and coil'64 energized, the core 67 is pulled upwardly into the solenoid and by magnetic attraction liftsnthe top sheet from the pile.

' Means are provided for energizing and deenergizing the various magnetic circuits in timed relation whereby a continuous operation is obtained; Obviously, any suitable arrangement of circuits and operation thereof may be adapted. For purposes of illustration, the magnets are arranged indfive circuits, oneincludingthe coils 33 of the opcrating magnet 28 in series, one including all of the electro-magnets, 58 of both magnetic lifting units 23in series, one including the upper coils of the magnets 63in series,'one including the lower coils64 of the magnets 63' in seriesfand the last including the sole 'noid 48; In the arrangement now tobe described, these five circuits are. controlled by five sets of contacts that are mechanically operated in any suitable manner. As shown in. the drawings, five pairs of 0011133015869, 7 0,

"71,72, and 73 are arranged to be closed in timed relation by'cams74, 75,i76,.77 and 78, mounted on a rotating shaft 79 driven by a magnet 28 to the main 86. Contacts complete a circuit from.main 85 through-=the 81 on the shaft of motor '52. Theupper con tact of. each pair maywbemounted on a stas tionaryarm 82 secured to the frame "1, and

the lower contacts mounted on a similar arm 83, the cams being arranged to bend the lower contacts upwardly intoengagement with the upper contacts in a manner well known-in 4 showing the arrangement of the circuit Assuming the apparatus is ready for operation, with the feeding fingers i 39 retracted bysprings 51, and with the magnetic lifting units 23 lowered into engageme'nt with the operate to' close the sets of contacts. 69, 70, and 71 substantially simultaneously. Contacts 69 complete a' "circuit, from ma inj85 through the operating coils 33in series of the magnetic lifting units 23- to'main 86, Cor.- tacts 71 completeacircuit from'mains85 through thecoils 65 in series of the magnets top sheet of the stack 5, cams 74, and 76;,

63 to the main 86; The energizationof these circuits causes the plu'ngers 67; of magnets .63 W5 to be held positively in engag'ement with the sheet, whil'e't'he magnetic lifting units are energized to hold the corners'of the sheet.

and magnet 28 isenergized to lift thelifting magnet. This operation results in bending or flexing the corners of the sheet upwardly freeof thenext adj acent'sheet, so as" swam-1 airtherebetween. After the corners have been bent upwardly, the-high point of cam 76 passes out of engagement with contacts which open, deenergizingthe holding-down coils 65, and at the same-time cam 77 operates to close contacts"7=2. Acircuit is not-completed. from main- 85 through contacts "7 2 and coils 64 in series ,to main 86,'and-the energizationof these coils liftsthe plungers'67 which liftwith them the rear'edge crane,

top sheet. Cam 77 now'operates'to closecontacts 7 3,]completingthe circuit of solenoid 48, whereby the fingers 39 are pulled forwardly to feed the fiieets oflthepile as above described. Preferably the liftingmagnets 23 are deenergized at this time to free the sheet by the high point of cam' 75 passing away from contacts 7O. Assoon as the'sheet has been pushed forward sufficient"- ly, contacts 69 and 72 are permitted to open magnets 23. fall back into engagement with by cams 74' a-nd 77 whereupon thelifti'ng the 'next'sheet, and as soon as the vfeeding strokeis completed, contacts 73 open'and springs 51 retract the feeding vfingers 39. The operation. is then repeated to separate. and feed the next sheet from therpileQ "fbeveled gear 80 meshing with abeveled gear In the embodiment illustrated in .Eigs S w to inclusive the electro-magnetiemeans described abovefor operating the magnetic lifting units 23 is replaced by suitable mechanical means for lifting and lowering the magnetic lifters, the operation of this embodiment being otherwise the same as described above. In this embodiment the magnetic lifting units 23 are carried by arms ly of each of said shafts. In the form shown,

one of the shafts 91 carries a bevel gear 95 that meshes with a bevel gear 96 secured to a transverse shaft 97 that rotates in suitable bearings formed on the frame 1." Shaft, 97 has an oscillatory motion which, as shown, is provided by a rock arm 98 secured thereto,

said rock arm having a pin and slot connection '99 with a rod 100 that is reciprocated vertically by means of an eccentric 101 secured to an extension of the shaft 79. The

i. as

wiring connections for the magnetic circuits are shown in Fig. 10, and, arethe same as Y I those shown above in Fig. 4, except that the operating magnet 28 with its coils 33 and the contacts 69 and cam 74: are omitted. The gear ratios employed are such that theraising and lowering of the magnets 23 takes place at a suitable speed, and the: contacts 70,

71, 7 2 and 78 are operated in timed relation with the oscillation of shafts 91 whereby the operation of the apparatus is the same .as that described above.

The apparatus above described is at once simple and economical to construct and operate, and provides rugged and reliable separation of sheets one by one from a stack of sheets. The magnetic lifting unit prevents penetration of the magnetic flux through'the top sheet of the stack' and at the same time obtains suflicient lifting effort by distributing, a flux of relatively low density over a.

relatively large area of the sheet whereby the tendency for the second sheet to be attracted with the top sheet is largely eliminated. A positive separation of individual sheets is afforded by the combination of mag netic lifting units of this character with means for holding down the adjacent portions of the sheet so that the same is positively bent or flexed prior to being elevated and fed on the pile. When the feed rollers 41 and 42 are operated at fairly high speed to move the sheets quickly off the pile, the sheets may be fed at a very'rapid rate. While only two embodiments of the invention have been described and, illustrated in the draw- .tion of said feeding means.

ings, it is apparent .that the inventionis capable of a variety of mechanical expressions and that changes may be made in the form, details of construction and-arrange ment of the parts,without departing from thespiritqof the invention. Reference is therefor to be hadto the appended claims for a definitionof the limits of the inventio What is claimed is: I

1. In apparatus of the class described ythe .combination of a lifting magnet adapted to lift a portion ofa sheet from a pile, av pivotally mounted arm supporting said magnet', means for rotating said arm about its pivot to lift said magnet, and means for feeding the lifted sheet ofi the pile.

2.. In apparatus of the class described, the

combination of a magnet adapted to lift the rear portion of a sheet from a pile, api'v otally mounted supporting arm for said mag- 3. In apparatus of the." class described. 7

means for-lifting the rear portion of asheet from a pile, a pivotally mounted supporting armfor saidmeans, a magnet'for rotating saidarm about its pivot to raise saidulifting means, and reciprocating means movable into engagement with theelevatedgrear por tion of the sheet to feed it forward}: i

'. 4:. In apparatus of the olass described, ,m-eans for lifting the. rear portion of a sheet from a pile, a pivotally mounted supporting arm for said means, means for rotating said arm about its pivot to raise said lifting means, means movable into engagement with the elevated rear portionof the sheet to feed it forwardly, and a magnet for moving said last-named means.

. 5. In apparatus of the class described, the combination of an electro-magnet adapted to life therear portion of a sheet from a pile,

a pivotally mounted supporting arm for said electro-magnet, an electro-magnet} for rotatng said arm about its plvot'to raise said first named electro-magnet, reelprocating means movable into engagement with the elevated v rear portion of the sheet, an electro-magnet for moving said means, and means for intermittently energizing the first two electromagnets and the last named electro-ma'gnet in timed relation. i

6. Inapparatus of the class described, the

combination of a movably mounted lifting magnet, magnetie means for raising" said I magnet to lift a portion of a sheet from a pile, meansmovable to engage said elevated portion to feed the sheet forwardly,and means for energizing said magnet and mag netic means in timed relation tothe opera 7., In apparatus of, the class described,the

Combination of magneticmeans for engaging a portion of a sheet, means for lifting said magnetic means to raise said portion,

magnetically operable means to take the sheet from said first means and feed it forwardly, and means for operating all of said means in timed relation.

8; In apparatus of the class described, the combination of a sheet lifting magnet, a pivotally mounted arm supporting said magnet, a .solenoid including a-movable member, means operatively connecting said member with said arm to rock the latter about its pivot to lift a portion of a sheet, and means for forwarding the sheet raised by said lifting magnet. v

9. In apparatusof the class described, a pair of lifting magnets adapted to lift portions of a sheet from a pile, pivotally mounted arms supporting said magnets, a solenoid having a pair of oppositely movable mem= hers, and means operatively connecting each of said members With one of said supporting arms.

10. In apparatus of the class described, a lifting magnet comprising a support and a plurality of electro-magnets mountedfthereon, the polarity of each electro-magnet differing from that of the adjacent electromagnet, and means for intermittently energizing said electro magnets.

I 11. In apparatus of the class described, a lifting magnet comprising a support, and a plurality of spaced electro-magnets carried by said support, said electro-magnets having a pole adjacent the pole of another electromagnet and differing in polarity therefrom to provide a substantially uniformly d1s tributed flux over the area covered by said 4.0 poles, and means for intermittently energizing. the electro-magnets.

12. In apparatus of the class described, a support and a plurality of sheet separating electro-magnets carried by said support and each movable relatively thereto, each electrolifting electro-magnet comprising support rality of spaced cores car said means,

ing means of magnetic material and a plu l a pole of each core having polarity difier- I ing from that of an adjacent pole of an adjacent core to provide a substantially uniformly distributed flux over the area covered energizing said electro-magnets.

EDWIN s. LINCOLN.

specification. W

magnet having a pole adjacent the pole of I an adjacent e'lectro-magnet and differing in polarity therefrom, and means for intermittently energizing said electro-magnets.

13. In apparatus of the class described, a

, lifting magnet comprising a support, a plurality of members of magnetic materialcarried thereby and movable relatively thereto,

and an energizing coil carried by each of said members.

14. In apparatus of the class described, a lifting magnet comprising a support, a plurality of members of magnetic materialcarried thereby andmovable relatively thereto,

and an energizing coil carried by eachof said members, said coils being connected for energization from a common source and being Wound to provide adjacent poles of unlike polaritv.

15. In apparatus of the class described, a

by said poles, and means for intermittently C

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