US2273823A - Sheet feeding mechanism - Google Patents

Description

` s sheets-sheet 1 INVENTOR ATT() EY W. H.` AYRES Filed May 4, 1940 SVM y@ 3 SHEET FEEDING MEGHANISM K Tf su Feb. 24, 1942.

Febo 24, W' H-AYRES SHEET FEEDING MECHANISM l Filed May 4, 1940 5 Sheets-Sheet4 2 INVENTOR 2;, l BY 41 A0.

Feb. 24, 1942.

w. H. AYREs SHEET FEEDING MECHANISM Filed May 4, 1940 3 Sheets-Sheet 3 INVENTR wm.N 7V. BY LA.. l0.

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v AT1-on EY l Patented Feb. 24, 1942 osi-reo str-s s l rarest l ortica William`H.,Ayres, Baltimore, Md., assigner to American Can Company, New York, N. Y., av corporation of 'New Jersey Application May4, 1940, SerialNo.33.3295` 1i Claims.

There are sometimes two of these feedv 'anA vbars in spaced vand parallel relation extending longitudinally of the machine and eachv bar` is provided with feed dog-s which are transversely parallel. A sheet upon entering the region of the feed bars sometimes has its rear or feeding edge out of parallel with the first set of feed dogs and usually the engagement of the feed dogs with the sheetl brings this edge into kparallelism with them. 'At high speeds it has been found that such aligning of the sheet by a rsingle dog striking against the sheet edge dents it to such an extent that considerable trouble is caused in subsequent operations upon the sheet or partsr thereof.

The instant invention contemplates overcoming this difculty by the use of a device'which aligns the sheet prior to its engagement by the feed dogs so that when the feed dogs pick it up for further advancement the force of impact is" Another object is the provision of such a feedi ing mechanism which permits of considerably greater feeding speeds so that the sheets may be propelled through the machine at highspeed without damage to the sheet edges.

Numerous other objects and advantages of the invention will be apparent as it isbetter understood from the `following description,` which,

taken in connection with the accompanying drawings, discloses a preferred embodiment I thereof. y

Referring to the drawings: Figure 1 is a top plan View of a portion of a scroll'shear machine embodying the instant invention, with parts broken away;

Fig. 2 is a longitudinal section taliensubstantially along the line 2-2 in Fig. 1, with parts broken away, 'the section `also showing a sheet entering the machine; w

Fig. 3 is an enlarged longitudinal section taken substantially along the line 3-3 in Fig. 1 and showing a sheet being fed, with parts broken away; v

Fig. 4 is an enlargedtransverse section taken substantially along the line lt--A in Fig. 1, with parts broken away;

Fig. 5 is an enlarged detail of the feeding del' vice as viewed substantially along the line 5-5 in Fig. 1, with parts broken away; and

Fig. 6 is an end elevation of the detail shown in Fig. 5, with parts broken away and parts shown in section..

As a preferred embodiment of the instant invention the drawings illustrate principal parts` of the sheet feed-in portion of a scroll shear` machine of the character disclosed in United States Patent 1,846,330, issued February 23, 1932,r

to M. L. I-Ieald. In sucha machine metallic sheets A to be operated upon are fed along a horizontal table Il (Figs. 1, 2, 3, and 4) in Ian intermittent or step-by-step motion so that a plurality of scroll edged strips will be cut from each sheet. This step-by-step motion is preferablyeffected bya pair of spaced and parallel feed bars l2 which operate in grooves I3 formed in the top of the table and which extend longitudinallyI of the machine. Gibs lil secured in the table overlap the feed bars and thus retain them against displacement.

Each feed bar l2 is provided with a plurality of spring held depressible feed dogs I6 which are spaced at equal intervals along the length of the bar. These dogs are' mounted on pivot pins Il which are securedin the feed bars. ITransversely of the table Il the feed dogs iii in the feed bars are arranged in parallelism so that a sheet delivered'onto the table in front of the dogs will be carriedforward in a squared position. For this purpose the feed bars are preferably tied together and are reciprocated in unison on a forward feeding stroke and then onareturn stroke in any suitable manner operating` in time with the other movable parts of the machine.

Delivery of a sheet A onto the table il in a proper position relative tothe first set of feed dogs I6 is preferably brought about by a feeding device which is connected-to the feed-in end oi" the table. This feeding device includes a feed table 2| which forms an extension of the machine table The feed table 2| comprises a plurality of spaced and parallel flat bars 22 which extend longitudinally of the machine. At one end of the table these bars are tied together by a round cross bar 23 which extends through brackets 24 bolted to the bottom of the bars. The two outside table bars 22 are formed with outwardly flared side guides 26 which guide the sheet in a straight line along the table. At the inner end of the table the bars 22 between the outer bars are tied together Iby a fiat cross bar 2l.

Adjacent the machine table the feed table 2| is supported on a rotating cross shaft 3l which is journaled in bearing brackets 32 secured to the outer end of the table Brackets 33 which are secured to the outer table bars 22 and to two of the intermediate table bars 22, surround the shaft and thus support this end of the feed table. The outer end of the feed table is supported on upright legs 34.

A sheet A placed upon the feed table 2| is propelled therealong toward the machine table Il by an endless chain conveyor 36 having a plurality of spaced feed fingers 3l secured thereto. This conveyor is disposed in the middle of the table and takes over a driving sprocket 38 which is secured to the cross shaft 3| and over an idler sprocket 39 which is keyed to a rotatable cross shaft 4| carried in bearing brackets 42 secured to the bottoms of the two outer table bars 22.

The driving sprocket 38 and its cross shaft 3| is rotated by an endless chain 45 which takes over a sprocket 46 mounted on the shaft 3| adjacent the sprocket 38 and over a sprocket 4l carried on a shaft 48 journaled in suitable bearings formed in the machine table The sprocket Y47 and the chain d5 are disposed in an opening 49 formed in the machine table. Shaft 48 constitutes the main machine drive shaft and is rotated in time 'with the other moving parts of the machine by Way of a driving Achain 52 which takes over a sprocket 53 carried on the shaft.

In order to properly advance a sheet when engaged by the feed dogs I6 so that all of the operations may be performed on the sheet and the sheet removed from the machine table the feed bars l2 may be reciprocated back and forth so that the actual lineal travel forward of the feed dogs I6 when in engagement with the sheet may be ve times as fast as the lineal travel of a feed finger 31 when engaged with the next succeeding sheet.

The sheet A propelled along the yfeed table 2| by the conveyor 36 is carried up onto the machine table by the conveyor fingers 37 and just as the rear edge of the sheet comes adjacent the inner conveyor sprocket 38 this edge of the sheet is squared up or brought into parallelism with the first set of dogs I6 of the feed bars |2 which are at this time in a rear-most position ready to engage the sheet and carry it forward through the machine.

squaring of the sheet in this manner is brought about by a pair of squaring devices 6| (Figs. 1, 5 and 6) which are carried .on the rotating cross shaft 3|. There is one of these squaring devices located on each side of the feed table 2| in the path of travel of the sheet.

Each squaring device 6| includes .a disc 62 having a hub 63 which is pinned onto the rotating shaft,3|. On its inner face the disc carries an arm 65 having at its outer end a sheet squaring finger 66 formed preferably with a straight squaring surface 61. At its opposite or inner end the arm is mounted on a pivot stud 68 secured in the disc. This pivoted end of the arm is formed with a boss 1| which engages against a spring barrel 12 retained in a lug 'I3 formed on the disc. A compression spring 'I4 disposed in the spring barrel presses the latter outwardly against the arm.

Intermediate its length the squaring arm 65 carries a cam roller 16 which operates on an edge cam 11. The spring barrel 12 maintains the cam roller in engagement with this cam. The cam is formed integrally with a plate 'I8 which is disposed on the cross shaft 3| but is free to rotate thereon, a collar 'I9 secured to the shaft being provided to prevent endwise displacement of the cam and its plate relative to the disc 62.

The cam 'Il and its plate 'I8 are positively rotated on the cross shaft 3| in a predetermined timed order relative to the other moving parts of the machine. This is brought about by an endless chain 8| which takes over a sprocket 82 bolted to the outer face of the plate 'i8 and over a driving sprocket B3 which is secured to the rotating cross shaft 4|. There is one of these chains @land its sprockets 82, 83 for each squaring device 6|.

Sprockets 82, 83 rotate the cam 'VI at a speed one half as fast as the squaring finger disc 62. In other words the cross shaft 3| which operates the sheet conveyor 36 makes two revolutions for each sheet delivered from the feed table 2| While the cam 'H makes only one revolution for each sheet. Thus the independently driven disc and cam constitute a differential mechanism in which the disc rotates faster than the cam.

The normal position of the squaring finger 66 as it is carried around with the disc is below or within the periphery of the disc where it is out of engagement with a sheet A passing over the squaring device. While in this position the cam roller 16 traverses a low part of the rotating cam. However, once for every two revolutions of the disc the cam roller catches up with a high portion of the cam and the squaring nger 66 is forced outwardly beyond the periphery of the disc.

The outward shifting of the squaring fingers 66 is effected in time with the travel of the sheet conveyor fingers 3l. This timing is such as to bring the squaring fingers up behind the rear edge of the sheet just at the critical moment when the conveyor fingers 3l are delivering the sheet A from the feed table 2| onto the machine table Il where the feed dogs I6 are waiting to engage the sheet.

The motion of the squaring ngers 66 is the resultant of two component motions, i. e., the ro tation of the disc 62 and the movement produced by the arcing which takes place when the cam H shifts the finger outwardly. These two motions impart to the squaring finger a resultant speed which slightly exceeds that of the conveyor finger 3l at the point of transfer from the feed table 2| to the machine table il. The faces 6l of the squaring fingers therefore engage the rear edge of the sheet and take it away from the conveyor finger 3l the While squaring the sheet into proper position. When the rear edge of the sheet is against the face 61 of both squaring'fingers 66 it is in a squared and proper position. Y

The feed bars I 2y of the machine proper are also actuated in time with the operation of the squaring devices 6I just explained and hence the duly squared sheet is immediately picked up, while still in motion with the squaring finger still in engagement withthe rear edge of the sheet and while still squared asy shown in Fig. 3, by the feed bars as they operate through aforward stroke. This carries the sheet through the machine.

As the feed bars I2 advance the sheetA throughl its first steppedv movement the rear edge of the vwith its rear edge in parallelism with the feed dogs I6 of the machine feed bars I2, the impact of engagement of the feed dogs with the sheet edge is gentle and isequally distributed between the dogs and denting of the sheet edge by this impact is thereby prevented. With such a feeding device `high feeding speeds are readily obi ing the sheet along a predetermined path of travel, instrumentalities for conveying said sheetsand for delivering them onto said feeding means, and rotary devices between said feeding means and said instrumentalities for aligning said sheet edge with said feed dogs prior to engagement by them, said rotary devices also maintaining said aligned sheet in motion while the feed dogs kengage the feeding edge of the sheet so that the impact of engagement of the dogs with the sheet edge will be gentle and evenly distributed between them to prevent denting of the sheet edge.

3. A sheet feeding mechanism, comprising, in combination a plurality of reciprocating feedl bars having feed dogs secured thereto for engaging the rear edge of a sheet for advancing the sheet along a predetermined path of travel, an endless chain conveyorhaving feed ngers for delivering a sheet the foregoing description, and it will be apparent that Various changes may be made in the form, construction and arrangement of the parts Without departing from the spirit and' scope of the invention or sacrificing all of its material adedge with said feed dogs prior to engagement by them so that thev impact of engagement of the dogs with the sheet edge will be evenly distributed between them to prevent denting of thel sheet edge. e

2. A sheet feeding mechanism,.comprising in combination feeding means including feed dogs for engaging the rear edge of a sheet for advanconto said feed bars, and a plurality of sheet squaring fingers operable in time with the delivery of said y sheet onto said feed bars and engageable against the feeding edge of said sheet for bringing said sheet edge into parallelism with the dogs on said feed bars and for maintaining the squared sheet in motion while the feed dogs come into feeding engagement with the sheet edge to prevent denting of the edge during this initial feeding engagement.

4. A sheet feeding mechanism, comprising in -combination a plurality of reciprocating feed bars having feed dogs secured thereto for engaging the rear edge ofa sheet for advancing the sheet along a predetermined path of travel, an endless chain conveyor having feed fingers for delivering a` sheet onto said feed bars, a pair of spaced rotatable discs adjacent the path'of travel of the sheet on said conveyor, a squari'ng finger pivotally mounted on each of said discs, a cam adjacent each of said discs for actuating said sduaring fingers, and means for rotating said cams in a differential relation to the rotation of said discs to give said squaring fingers a component arcuate motion in time with the delivery of the sheet onto the feed bars for engaging the feeding edge of the sheet and for bringing it into parallelism with said feed dogs prior to its engagement thereby, said squaring fingers accelerating the sheet to carry it away from said conveyor fingers and maintaining the sheet in motion while the feed dogs come into feeding engagement therewith to prevent denting of the sheet edge by the dogs.

WILLIAM H. AYRES.

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