US2741479A - Sheet feeding machines - Google Patents

Description

April 10, 1956 H. T. BACKHOUSE ETAL 2,

SHEET FEEDING MACHINES Filed Oct. 50, 1951 s Sheets-Sheet 1 April 10, 1956 BACKHOUSE ET AL 2,741,479

SHEET FEEDING MACHINES Filed 001;. 50, 1951 5 Sheets-Sheet 2 by I a {I A-nvRuEYs April 10, 1956 H. T. BACKHOUSE ET AL 2,741,479

SHEET FEEDING MACHINES Filed Oct. 50, 1951 3 Sheets-Sheet 3 ATTORNEYS United States Patent i 2,741,479 SHEET FEEDING MACHINES Headley Townsend Backhouse, Nassau, Bahamas, British Fest Indies, and William James Pirie, Edinburgh, Scot- Application October 30, 1951, Serial No. 253,807

Claims priority, application Great Britain October 31, 1950 Claims. (Cl. 27160) the printing or other machine, and a side lay against which the side edge of each sheet is registered before the sheet is transferred. The sheets may be supplied to the layboard by conveyor means either individually or as a continuous stream of partly overlapping sheets.

When sheet feeding machines of the kind described are in use the registered sheets are transferred from the layboard to the printing or other machine by means of grippers which engage the sheet at spaced positions along its front edge and take it into or towards the printing or like machine. A difiiculty which arises in practice is that the registered sheets may not lie quite flat on the layboard and consequently the edge may not be properly presented for engagement by the grippers. For instance, if a portion of the front edge of a sheet, which is to be received within the mouth of a gripper as the gripper moves rearwardly to engage the sheet, is raised above the layboard the edge may meet a portion of the gripper and be pushed back or buckled. A further and, usually, less serious difficulty is that the width of the portion of the sheet between the side edge which has been registered and the grippers may vary from sheet to sheet, due for example to waves in the sheets, with the result that the exact side registration obtained against the side edge is lost in the transfer of the sheet to the printing or other machine. It is an object of the invention to reduce either or both of the above difiiculties.

According to the invention a machine of the kind described is provided with a smoother which is adjacent to the front lays and which extends across the layboard over the width of the front portion of a sheet at the front lays, or across a substantial part thereof, thereby to maintain the said front portion substantially fiat for engagement by grippers or the like by which the sheet is to be transferred to the printing or other machine.

The smoother may extend across the width of the layboard between the outermost grippers and preferably it extends across the whole operative width of the layboard.

The smoother may be supported for adjustment towards and away from the front lays.

It is also preferred that the smoother leaves the front portion of the sheet available for inspection.

To facilitate the feeding of the sheets to the front lays and the subsequent removal of the sheets, means may be provided for raising and lowering the smoother, the smoother being lowered onto each sheet after the sheet has reached the front lays and being raised immediately after the sheet has been engaged by the grippers. The smoother may descend onto the sheet before or after the sheet is moved up to the side lay,

2,741,479 Patented Apr. 10, 1956 the latter arrangement having the advantage that the smoother does not interfere with the sideways movement of the sheet, but the disadvantage that the smoothing of the sheet may have to be effected with undue rapidity unless delay in the removal of the sheet is to be permitted. The choice between these alternatives will, in many cases, depend upon the time available between the arrival of the sheet at the front lays and the taking of the sheet by the grippers, and the manner in which that time interval is appropriated, in the other circumstances of the machine, to the various operations to be performed such as the settling of the sheet at the front lays and the side laying of the sheet. If the smoother is to descend before side registration is effected sufficient time should be allowed for the sheet to settle against the front lays before it is engaged by the smoother.

it is preferred that, when the machine includes means for raising and lowering the smoother as just described, the means are so arranged as to give to the smoother a downward movement which is perpendicular to the sheet or has a small component in the forwarding direction thereby to ensure that the smoother does not tend to withdraw the sheet from the front lays as it is lowered on to the sheet.

Four specific embodiments of sheet feeding machines according to the invention will now be described by way of example, and with reference to the accompanying drawings which are largely diagrammatic and in which:

Figure l is a perspective view illustrating the first example, and

Figures 2-4 are similar views illustrating the other three examples respectively.

In each of these machines there is a layboard I having front lays 2 and side lays 3 (not shown in Figure 3) and tape conveyor means 4 (shown only in Figure l) for feeding the sheets in succession to engage the front edge of each sheet 5 with the front lays 2. Means, not shown but operating in well known manner, are also provided for drawing the sheet sideways up to the side lay 3.

At each side of the layboard 1 a short distance behind the front lays 2 there is, in each of the first three examples, an upstanding bracket 6 providing a bearing for a shaft 7 which extends across and above the board 1. At one end this shaft 7 has a downwardly directed arm 8 with a follower 9 which engages a cam 10 to effect a rocking movement of the shaft 7.

In the construction according to the first example, shown in Figure 1, the shaft 7 has two arms 12, one at each end thereof immediately inside the supporting bracket 6, which extend forwardly to a position just behind the line of the front lays 2. A length of piano wire 13 is stretched between the free ends of the two arms '12 at the under side thereof and provides the smoother surface to engage the sheets. In use, after a sheet has reached the front lays 2 the shaft 7 is rocked to lower the piano wire 13 into contact with the sheet so as to ensure that the front edge of the sheet is sufliciently flattened to facilitate easy and certain engagement by the transfer grippers and at a position close to the front edge but sufiiciently far away therefrom to leave a portion of the sheet exposed for engagement by the transfer grippers. After the sheet has been engaged by the grippers the shaft 7 is rocked to lift the wire 13 from the sheet.

In the second example, shown in Figure 2, the wire 13 is replaced by a light roller 15 of metal or other material which will permit the sheet to slip sideways for side registration, when the roller 15 is lowered before the sideways movement. This roller 15 is carried in forks 16 in the ends of the arms 12 and is guided for up and down movement by two additional brackets secured t t l yboard .3 and ,hatin slqt .r fiuhisl slope upwardly and backwardly relative to theboard (i. e. away from the lays), and through which the ends -of the roller lS pass. This arrangementensures that-the smoother does not tend to withdraw the-sheet from'the lays'but, on the contrary, tends to hold the sheet up to the lays. To avoid interference with the side-laying. operation the roller -may, if desired, be lowered onto the :sheet' after the operation has been effected.

- in the third exampla shown in Figure 3, there is a strip of ,a transparent plastic material with its rwidthiextending forwardly from the shaft 7 so-that its front edge 21 is positioned to -engageajustwbhindlhc frontlays 2 a sheet on the layboard 1. Thisirontedge 21 constitutes the smoother. The plastic strip '20 has, at each .cnd, a boss 22 which its over a guide pillar .23 Zupstanding from the layboard -;1 -and sloping hackwardly so that the strip 20' is constrained for up and downmovements with :a forward componentto; the downward ,movement so that as thesrnoother is lowered 7 onto the .sheet'it has a small forward movement tending to holdihe sheet against the frontlays. The-bosses 22 also have projections 24 which are received within forks 16 in the ends of armsattached to theshaft 7, as in ;the last example, so that rocking movement of the shaft 7 will raise and lower the strip 21).

in ;the above constructions the brackets 6 ca r1;y ing the; shaft-7 in the first example (Fig. 1), the ,guide brackets ,17 .of the .second example -(Fig. ,2) and' -t he pillars 25 of the third example (Fig. 3) may =all he made adjustable in position on the layboard 1 towa gds and away from the 'front lays 2 for the purpose of enabling the position of the smoother to be-v aried e g. to, suit :sheetsof .s-diiferent materials such as paper -and card. 7

- rIn the fourth example, shown in Figure 4, the shaft 7 .isrsecured to. the ends, of upwardly directed arms on a gro ck shaft -32 pivotally supported below the lay board}. One of these arms bt) is part of a hell-crank lever .31 of whichthe other arm 33 carrie a-follower 13.4. engaging a;cam 35 by which the levert31 isrocked .to move-,the.srnoother bar 36 upwardly and back-weirdly. In this example the shaft 7 carries four arms-.12 and the smoothenhar 36 is divided into two-sections, thereby facilitating ;manufacture and handling of the that. The grippers by which the sheets tare taken to the printingmachinetare shown diagrammaticallyat 37.

Inueach of the above examples the smoother may beflowered toengage the sheet immediately after the sheet has reached the front lays land had-time to settle .or ;the, lowering-may be delayed until after side registration has been effected. V rltjis swithin the invention to provide'lside lays 3 at eacheside-of the machine, the side lays beingfor alternatige;.use, .and ,to arrange :the side-lays for-adjustment :across the layboard ,1. 'With this .arrangement the ssrnootherimay extend across, the layboard oyera width qrreaqsdiast h maximum genera ion 2 th sid lays.

We claim:

1. A sheet feeding machine comprising a layboard the upper surface of which is fiat near its forward edge, aligned front lays adjacent that edge of the layboard, aligned sheet grippers arranged \to make gripping engagement with the front edge portion of a sheet din a s id q on Ja s .isin he w a r ig sheet-engaging surface directed toward the layboarri land extending substantially continuously across at least a major portion of the width of the-layboardaboye and behind said edge and parallel tandtcloseto said edge and to said lays, the saidsheehengaging surface of the smoother being arranged to press down onto the flat part of the layboard a-sheet lyingthereon with. its edge adjacent the lays, and means for raising the smoother from the layboard and for lowering it onto thesheet yi g o the l y rd .w ha c pon nt fn o ement towards the lays, r h rebyth r n edg Qf-th s e is .held against said lays and also flattened toensure engagement thereof by said grippers. T

2. A,sheet feeding machine as claimed ,in claim 1 in which the raising and lowering meansaforesaid comprisetwo arms supported atpo sitions spaced apart in the-crosswise direction of thelayboard-for pivotal movement about an axis-below the layboard and behind the smoother, the armsextendingfrom the pivotal axis towards the forward edge of the layboard and carrying the .smootherin front of and above Said .axis.

3. A sheetfeeding machine asclaimed in claim 1 in which the means aforesaid include inclined guides constraining the smoother to move upwardly and downwardly in a path which slopes downwardly and towards the front lays. 7 a V 4. A sheet feeding'machine as claimed in claim 1 in which the smoother comprises a wire and means for holding thewire stretched across theboard.

SI A sheet feeding machine as claimed in claim 1 in Which thesrnoother comprises aro ler providing the smoother surface and means for supporting the roller extending across the board.

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