US2554320A

US2554320A - Sheet feeding mechanism

Info

Publication number: US2554320A
Application number: US635971A
Authority: US
Inventors: Battey Alfred Pierssene
Original assignee: R Hoe and Co Inc
Current assignee: R Hoe and Co Inc
Priority date: 1944-12-11
Filing date: 1945-12-19
Publication date: 1951-05-22
Anticipated expiration: 1968-05-22

Description

y 22, 1951 A. P. BATTEY SHEET FEEDING MECHANISM Filed Dec. 19, 1945 INVENTOR @Zud I 5? ATTORNEY Patented May 22, 1951 SHEET FEEDING MECHANISM Alfred Pierssene Battey, Eastcote, England, as-

signor to R. Hoe & Co. Inc., New York, N. Y., a corporation of New York Application December 19, 1945, Serial No. 635,971 In Great Britain December 11, 1944 Section 1, Public Law 690, August 8,1946 Patent expires December 11, 1964 12 Claims.

This invention relates to sheet feeding mechanism especially intended for feeding sheets to a printing (or other) machine and more particularly but not exclusively for feeding sheets by the system known as stream feeding in which the sheets travel from the supply position to the printing machine in partly lapped formation.

The invention is more especially concerned with that kind of mechanism in which the rear end of the top sheet of a stack of sheets is engaged by sheet lifting devices commonly in the form of pneumatic suckers which when elevated lift the rear end. of the top sheet away from the stack, a presser foot or feet then being inserted between the lifted sheet and the stack and allowed to drop on to the stack so as to hold and prevent movement of all sheets except the lifted one when the lifted sheet is moved forward. To separate the lifted sheet over the whole of its surface from the stack, an air blast is directed forwardly beand the centre of the sheet where they exercise Obviously as the forwarding 'difiiculty sheets of different thicknesses; it may ables the sheet feeder to be applied to what is commonly known as a stream feeder system tween the lifted rear end of the top sheet and the top of the stack, and it is common to form the presser foot hollow to constitute an air jet for that purpose. The sheet is then engaged by forwarding devices also commonly in the form of pneumatic suckers which take the sheet from the lifting devices and are operated to enable the sheet to be forwarded to the printing machine.

Proposals have been made to stretch sheets by separating the lifting pneumatic suckers which lift the top sheet from a stack and present the stretched part of the sheet to a pneumatic forwarding device. In one such proposal the lifting.

suckers were disposed at the rear end of the sheet and pneumatic forwarding devices in the form of pneumatic suckers were arranged to grip the sheet in the region of the stretched portion of the sheet between the lifting suckers when these latter suckers were at or near the end of their lifting operation.

Now, the present invention utilises sheet lift ing devices which are moved apart to stretch the top sheet as it is lifted from the stack but according to this invention the forwarding devices are disposed to engage the top sheet in a region where the sheet is not (or is not substantially) lifted or strained by the action of the lifting devices. The lifting devices are, with the presser foot and air blast nozzle, disposed to operate on the rear part of the sheets i. e. near their trailing edges regarded in their direction of feed to the printing machine and thus the forwarding devices (preferably in the form of pneumatic suckers) are disposed forwardly of the rear part of the sheet and preferably between the rear edge an efiicient control. devices operate forward of the part of the sheet which is raised and stretched to facilitate sheet separation, these devices are enabled to effect "their forwarding action by a movement which is in line more or less with the natural fiat or horizontal condition of the sheet the sheet being at this part but little raised from the stack. This enables the forwarding devices to handle without be observed that for thicker sheets the control is obviously exercised advantageously nearer the centre of gravity of the sheet. While affording the advantages referred to, the invention also enwhere the leading edge of one sheet lies under the trailing part of the preceding sheet, the sheets passing in this fashion to sheet conveyors such as endless belts or rollers which convey the stream to the printing machines. The conveyors may, travel either at a constant speed or have avariable speed or fslow down motion timed to each cycle of operations to reduce the speed at which the sheet is delivered to the registering apparatus on the printing machine.

Reference will now be made to the accompanying drawing in which Figures 1 and 2 are re-. spectively diagrammatic plan and side elevation while Figure 3 is a perspective view of the mechanism according to this invention at one side of a sheet stack it being understood that similar mechanism would be provided at the other side of the stack.

Referring to the drawings I indicates a stack of.

sheets from which sheets are to be taken and forwarded one at a time from the top, the stack be'. I

ing carried on a table which in the usual way is raised automatically to maintain the top of the stack at an approximately constant level as sheets 1 are removed.

Disposed in a line over and parallel with the rear edge of the stack are two sheet lifting devices in the form of

pneumatic suckers

2, 3,

These

suckers

2, 3 are arranged for movement not only towards and away from the stack but" also laterally towards and away from one another as indicated by the arrows X. c

There are also provided two combing? wheels of which only one is shown at 4 and which are being engaged by the lifting suckers. Between the lifting suckers is arranged one (or more) and as shown two nozzles 5, 6 formed to provide a presser foot to engage and hold the second sheet of the stack (and in consequence the'other sheets of the stack) near or at its trailing edge.

With the mechanism so far described, the combing wheels are first lowered to the top sheet-"- indicated at S and rotated to createethee-bulges near the rear corners of the top sheet of the stack; the

lifting suckers

2, 3 are-nowrenderedifi operative to take the sheetsatthe crest of the bulges so formed; the combing wheels are, with the presser feet 5, 6 now raised

andithemthelifteing suckers

2, 3 are lifted and moved; apart,-.the1 presser feet being also swung rearwardly clear of the rear edge of the top sheet S: these oper*-" ations overlap to some extent so that the-opera tion described causes the rear part of :thetop sheet S to be lifted and also stretched, the presser feetbeing clear ofethe. sheet to allow. its. being. lifted.. This is the positionof the .partsshown. in Fig. 3. The presser feet .then continuetheir... operation by beinglowered and moved forwardly below the lifted .andstretched rear. edge .ofthe top sheet. S'and'so. comes into contact with thesecond sheet to hold. it as. is shown. in Figure 2;

whenthe feet-are in engagement. with,.the.-sec-.

ond sheet air underpressure is'supplied. .tothe nozzle. which. directs the air. forwardly, between. the .top andtsecond. sheet of the stack and..so. assistsin separatingthe two sheets.

In additionto, the mechanism described,.there.. are providedforwarding pneumatic suckers 1,. 8..

whichare disposedover the sheet. stack. ahead of thelifting suckers 2,-3and preferably between. the. centreand the rear edgesof thesheetsand in any .case. beyond. the region v.in. which-.the

stretching of the. topsheet between the lifting: suckers has any appreciableeffect.

Theseiorwarding suckers. 7,. 8 of. whichthere would beasshowniat least two disposed in alineparallel with. the rear edge. of. thesheets, could be arranged .for a reciprocating. movement. asindicatedby the arrows .Y in a. plane more. or less. parallel withv the desired direction. of sheet feed to effect thedesired forwardly action:. in. addition they may have araising and lowering motion imparted. to'th'em so as (in .comebinationwiththe control of vacuumapplied). to. take chargeof and release a sheet.- These for: wardingsuckers l, 8 and.the.-lifting suckersare. timed in their operationso that.when..suction.is.. applied to the forwarding. suckers. it. is released. from the lifting

suckers

2,3 whereby the sheet. is, freed. from restraint by the lifting suckers at the time that the forwarding suckerstakecharge of the. top sheets to.-effect.their feedingroperae. tion.. During. part of. the feeding,operatiomthe.. air blastmay continue. to. be directedbetweenthe. top and .second sheets to assistthe forward. ing suckers I, 8 in the forwarding operation..

During the-forwarding operation of the suckersl'L. 8 the leading end. of. the .top sheet S1 will.

pass tothe controlof .the usual feed.rollers.or-. belts. operating. to .feed thesheet to the printing machine, this-sheet, when the stream feeder.

system is employed, being trapped, .at .its. leading.

end, below the preceding. sheet,

The forwardingmechanism may includea drop roller which isliftedtoallow.ofthe free passage ofthe leading edges of the sheets andthenlowa eredto control and feed the sheets,-

The. mechanismfor effecting the operation of.-

thevarious parts. maybeof any known form:

Figure 3 shows an arrangement of the. mec anism which is so well-known that only a brief description of the mechanism will be sufficient, it being understood that this invention is not concerned'withlthe mechanism .but -with the dispositionof parts'operating on the sheets.

The

pneumatic suckers

2, 3 are carried each by -an arm 12 supported by a bracket l3 pivotally carried about .a vertical pivot I3 at the outer end of an arm [4 operated by a cam I5 on a shaft l6".- As this cam rotates, the arm I4 is rockedtoraise' andilower the suckers 2', 3. The bracket l3 'is caused' by a fixed plate I! to rock aboutthe.- vertical pivot I3 as the bracket is raiSedJandloWered' and this imparts the movement of one sucker 2 away from the other sucker 3 to 'effect stretching of the sheet.

The presser feet 5, 6 are each carried by supports I 8 -.depending from a plate [9 on an arm 20 caused to rock by a cam.2l, the plate l9 having in it a cam.slot 22 engaged by a fixed pin- 23 so that as the arm 20is rocked to raise and lower the foot 5 (or 6) the plate I9 is itself caused to.

rock'by the cam 22 to swing the foot rearwardly to clear. the liftedtop sheet S and then forwardlybetween that sheetv and the top of the stack.

Theforwarding suckers I, 8. arecarried each on' a slider 24 mounted on a fixed. guide bar 25*;thes1ider being coupled by a link 26 to an arm 21' on ashaft28 which is caused to oscillate: thus the sucker l (or 8) is caused to reciprocate forwardly on its'forwarding movement and rearwardly on its return movement.

The'combing wheels. 4 are rotatable each ina pivotedbracket 29 controlled by 'a cam 30 on the shaft l6, the'cam raising and lowering the combing'wheel which is rotated about its own axis by'gearing indicated at 3!.

The nozzles. 9, lfi'are carried from the arms I4 so.that these nozzles can be adjusted laterally with the lifting sucker assembly.

The various parts are arranged for lateral ad.

justment. (i. e. across the width of the sheeti byrbeingslidable on guide rods 32, 33..

In addition-.to-the air jets provided by. the

pressenfeet 5,.6 other air jets wouldbe supplied sembly of

thesuckers

2, 3 ashas been described so that-the nozzles. 9, ID are adjustable with the assembly for the

suckers

2, 3; this however necessitates .that .the nozzles 9, ID are lifted and lowered in step with the lifting and lowering ,of. the suckers, 2,.3.and it thus follow 'thatthe timing. ofoperation of the nozzles.9,- I0 is governed by, the timingof. operationof the suckers-2, 3.-

Asthearrangement of this invention provides forwarding suckers F, 8which are disposed totake the top sheet of the stack at'a zone clear of.the.influence-by the lifting

suckers

2, 3 which inthe preesnt case do not transfer the lifted and.

stretched edge of the top sheet to the forwarding suckers, it is possible to lower the lifting

suckers

2,3 and hence the nozzles 9, I0 at an early'time andso. to. afford a prolonged period for the op:- eration of the nozzles 9, I0. In fact inthe present case the.function of the lifting suckers 2,3is

mainly to lift and stretch the'rear edge of the topsheet 5 to facilitate the introduction of air jets between that top sheet and the next sheet of the stack to ensure the separation of the top sheet S from the stack and the forwarding of that sheet alone by the forwarding suckers I, 8.

To assist further in the separation of the sheets, other nozzles, only one of which is shown at H in Figure 3 can be provided to direct air jets at the side of the stack; these jets may in some cases enable the combing wheels 4 to be dispensed with.

The bars 25 may be mounted at their rear ends for adjustment about vertical axes; this would enable the bars to be adjusted in relation to the edges of the stack to enable the direction of movement followed by the sliders 24 to be set to suit the individual stacks being handled, the bars being of course locked in the selected position.

What I claim is:

1. In mechanism to take and forward sheets .from a stack, the combination of sheet-lifting devices, means to support said devices in spaced relationship at the rear end portions of the top.

sheet of the stack, means to raise and move apart the said devices to raise and strain the rear end of the top sheet, a combined presser-foot and airblast member, means to introduce the said member between the lifted and strained top sheet and the next sheet of the stack, means to supply air under pressure between the lifted and strained portion of the top sheet and the next sheet, sheet forwarding devices, means to hold said forwarding devices in position to engage said top sheet ahead of the position of the lifting devices and beyond the area raised and strained thereby, and means to operate said forwarding devices to forward the top sheet from the stack.

2. In mechanism to take and forward sheets from a stack, the combination of sheet-lifting devices, means to support said devices in spaced relationship at the rear end portions of the top sheet of the stack, means to raise and move apart the said devices to raise and strain the rear end of the top sheet, a combined presser-foot and airblast member, means to introduce the said member between the lifted and strained rear part of the top sheet, sheet forwarding devices, means to hold said forwarding device in position to engage said top sheet ahead of the position of the lifting devices and beyond the area raised and strained thereby, and means to operate said forwarding devices to forward the top sheet from the stack.

3. In mechanism to take and forward sheets from a stack, the combination of sheet-lifting devices, means to support said devices in spaced relationship at the rear end portions of the top sheet of the stack, means to raise and move apart the said devices to raise and strain the rear end of the top' sheet, combined presser-foot and airblast members, means to introduce the members between the lifted and strained top sheet and the next sheet of the stack to supply air under pressure between the lifted and strained portion of the top sheet and the next sheet, means to direct air under pressure against the rear edge portions of the upper part of'the stack, sheet forwarding devices, means to hold said forwarding devices in position to engage said top sheet ahead of the position of the lifting devices and beyond the area raised and strained thereby, and means to operate said forwarding devices to forward the top sheet from the stack.

4. In mechanism to take and forward sheets from a stack, the combination of sheet-lifting devices, means to support said devices in spaced relationship at the rear end portions of the top sheet of the stack, means to raise and move apart the said devices to raise and strain the rear end of the top sheet, a combined presser-foot and airblast member, means to introduce the said member between the lifted and strained rear part of the top sheet, means to direct air under pressure against the rear edge portions of the upper part of the stack, sheet forwarding devices, means to hold said forwarding devices in position to engage said top sheet ahead of the position of the liftin devices and beyond the area raised and strained thereby, and means to operate said forwarding devices to forward the top sheet from the stack. P

5. In mechanism to take and forward sheets from a stack, the combination of sheet-lifting devices, means to support said devices in spaced relationship at the rear end portions of the top sheet of the stack, means to raise and move apart the said devices to raise and strain the rear end of the top sheet, a pres-ser-foot mechanism, means to introduce the mechanism between the lifted and strained top sheet and the next sheet of the stack to supply air under pressure between the lifted and strained portions of the top sheet and the next sheet, sheet forwarding devices, means to support and constrain the forwarding devices for movement in sheet-forwarding direction and to hold the devices in position to engage the top sheet ahead of the position of the lifting devices and beyond the area raised and strained thereby, means to move the forwarding devices in sheet forwarding direction and means to adjust the setting of the supporting means for the sheet forwarding devices in relation to the stack.

6. In mechanism to take and forward sheets from a stack, the combination of sheet-lifting devices, means to support said devices in spaced relationship at the rear end portions of the top sheet of the stack, means to raise and move apart the said devices to raise and strain the rear end of the top sheet, a combined presser-foot and airnozzle member, means to introduce the said member between the liftedand strained rear part of the top sheet, sheet forwarding devices, means to support and constrain the forwarding devices for movement in sheet forwarding direction and to hold the devices in position to engage the top sheet ahead of the position of the lifting devices and beyond the area raised and strained thereby, means to move the forwarding devices in sheet forwarding direction and means to adjust the setting of the supporting means for the sheet forwarding devices in relation to the stack.

7. For forwarding sheets singly from a stack, means to lift and strain the rear end portion of the top sheet of the stack, means to introduce between the raised part of the top sheet and the next sheet of the stack a member to hold the next sheet of the stack and to supply air under pressure between the two sheets, and means to take the top sheet at a zone ahead of the raised portion and to forward the sheet.

8. For forwarding sheets singly from a stack, means to lift and strain the rear end portion of the top sheet of the stack, means to introduce between the raised part of the top sheet and the next sheet of the stack a member to hold the next sheet of the stack and to supply air under pressure between the two sheets, means to direct air under pressure against the upper part of the rear portion of the stack, and means to take the top sheet at a zone ahead of the raised portion and to forward the sheet.

9; For." forwardingv sheets singly; from a stack,-, means ,to;lift andstrain: the rear end portion of' the topsheet' of: the stackymeans to direct air under'pressure'against the upper portion-.of the rear: end of therstaek, the said two-means form-'- ing a'unitary structure, means to introduce betweeirthe raised part of-the top sheet and thenext sheetof the stack a member to hold the-next sheet of:the stack and to supply air under pressure betweenthe twosheets, and means to takethe-top sheet at a zone ahead of the raised portion and to 'forward the sheet.

10: For forwarding sheets singly from a stack, means to create a bulge-inthe rear part ofthe top sheet of the stack, means to engage-the bulged portion of the top sheet to lift and strain the said rear end portion of the top sheet, means to introduce between the raised part of the top sheet and the next sheet of the stack a member to hold the next sheet of the stack and to supply air under pressure between the two sheets and means to take the top sheet at a zone ahead of the raised portion and to forward the sheet.

11. For forwarding sheets singly from a stack, means to create -a bulge in the rear part of the top sheet of the stack, means to engage the bulged portion of the top sheet to lift and strain the rear end portion of the sheet, means to introduce between the raised part of the top sheet and the next sheet of the stack a member to hold the next sheet of the'stack and to supply air under pressure between the two sheets, means to direct air under pressure against the upper part of the 8. rear portionrofz the-:stack and-means-to take. the topsheet at a zone ahead of the-raised portion and to forward the :sheet.

12. For forwardingsheets singly from a stack, meansto create abulge in-the rear. part of the top sheet of the stack, means toengage the bulged portion of the top sheet to lift and strain the rear end portion'of the top sheet, means to direct air under pressure against the upper portion of the rear end of the stack, the said two means forming a unitary structure, means to introduce between the raised part of the top sheet and the next sheet of, the stacka member. to hold the. next sheet of;the=stack andto supply air under pres- ;sure between the two sheets,v and means to take the top sheetat a zone ahead of the raised portion and to forward .the sheet.

ALFRED PIERSSENEBATTEY.

REFERENCES CITED Thefollowing references are of record in the file of, this patent:

UNITED STATES PATENTS Number Name Date 1,498,965 Henderson June 24, 1924 1,715,358- Harrold- June 4, 1929 2,085,612 Spiess June 29, 1937 2,108,702 Backhouse Feb. 15, 1938 2,284,430 Jirousek May 26, 1942 2,389,480 Baker. Nov. 20, 1945 2,402,442 Perry June 18, 1946