US2042734A

US2042734A - Preselecting device for sheet-feeding mechanisms of stenciling machines and the like

Info

Publication number: US2042734A
Application number: US37741A
Authority: US
Inventors: Roy Aime Armand
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-08-28
Filing date: 1935-08-24
Publication date: 1936-06-02
Anticipated expiration: 1953-06-02

Description

June 2, W36. A A ROY 2,M2,73%

PRESELECTING DEVICE FOR SHEET FEEDING MECHANISMS OF STENCILING MACHINES AND THE LIKE Filed Aug 24, 1955 2 Sheets-Sheet l Jame 2, W36. A. A. ROY 2594277343 PRESELECTING DEVICE FOR SHEET FEEDING MECHANISMS OF STENCILING MACHINES AND THE LIKE Filed Aug. 24, 1935 2 Sheets-Sheet 2 Patented June 2, 193

UNITED STATES PATENT OFFIL'IE Aim' Armand Roy, Lyon, France Application August :24, 1935, Serial No. 37,741 In France August 28, 1934 10 Claims.

In stenciling machines the sheets are fed in succession from a pile of sheets to the stenciling member. The sheets show a tendency to stick to each other, principally along their edges when they have been cut by 'a somewhat imsharp knife, and the feeding mechanism therefore sometimes feeds two sheets at the same time or, when feeding a sheet, :displaces the next one from its correct position on the pile, whereby it is afterwards stencilled at a wrong place along its height. The operator frequently has to raise a corner of the first sheet and to retain the second sheet of the pile during the whole stenciling operation.

In ;-printing presses it has been proposed to provide sheet-buckling members acting on the top-sheet of the :pile to separate it locally from the second sheet, the latter being eventually retained by pads or pressing blocks. But in the devices hitherto known it has :been necessary :to adjust the height of the top sheet either manually :or automatically :during the operation. This is a considerable drawback in connection with stenciling :machines.

According to my invention the sheet-buckling member is supported by a freely vertically :movable carriage which presses said member on the pile by own weight.

The sheet-retaining :member is preferably in the form of a pressing b'lock made of rubber, while the member adapted to displace the first sheet or sheet-buckling member is .a roller supported by an oscillating arm and prevented from rotating by a :pawl-tand-ratchet mechanism whereby it may return freely and without at the same time returning the displaced sheet. But both members may also be in the form of one and the same roller or group of rollers, provided the direction of the feed is parallel to the axis of said roller or rollers.

.In the annexed drawings:-

Fig. '1 is a. side view of a :device according to this invention. 1

Fig. 2 is a front view thereof.

Fig. 3 is a plan yiew thereof.

Figs. 4 m9 are diagrams showing theoperation of the device.

Fig. 10 diagrammatically shows a rmodified form :of a :device according to the invention.

The stenciling machine is not illustrated in the drawings since it may be of any construction. .It embodies, :as usual, a stencliling mechanism of any description and a sheet-feeding mechanism.

The sheets are fed :from a sheet-supporting plate partly shown at l, the .pile of sheets .beirm indicated at -2. Abutments or guides 3 are arranged on plate I, as usual, along the two lateral sides of the pile and along its .outer .end.

Plate I carries an upright 4 which forms guide for a vertically sliding carriage .5. The upright 4 is preferably rectangular in cross-section, as shown, whereby carriage 5 is prevented from rotating. Carriage 5 is formed with a projection 6 which supports the pivot 1 of a double lever 8 carrying at its lower end vtwo rubber-coated rollers 9, loose on their spindles but prevented from rotating in one direction by pawls .|.0 cooperating with oorrugations provided along the periphery of said rollers. The latter are in contact with the pile of sheets 2.

The upper end of lever 8 is pivotally connected with a rod H having a reciprocating motion in synchronism with the sheet-feeding mechanism. For instance, in a stenciling machine of standard design, rod l I may be driven by a=cam keyed on themain shaft.

The carriage 5 also supports the pivot t2 .0! a bell-cranked lever I3 one .arm of whichls pivotally connected with a vertical rod 14 which passes-through a guide 15 fixed to carriage 5,.and terminates into a rubber-coated block 16 which is pressed against the sheets of paper 2 by a spring H.

The other arm of lever I3 is actuated by a pawl 18 loose on a pin 19 forming the pivot which connects rod H and lever B. At the end of the .stroke of rod H to the right (Fig. .1) the free end of pawl [8 contacts a sloping abutment 2.0 fixed to carriage 5, whereby it .is raised, thus freeing the end of lever 13.

The carriage 5 with its related parts is supported by rollers 9 resting on the sheets 2, spring I being not strong enough to lift the carriage. As the thickness of the pile decreases, carriage 5 gradually comes down.

The device operates as follows:

The sheet-feeding mechanism being inoperative (i. e. between two successive feeds) androllers .9 being at-the position of Fig. 1, rod Ill moves to the right (direction of arrow 21, Fig. 1) thus rocking lever 8 and moving rollers .9 to .theileit (direction of arrow 22, Fig. 1). The latter are prevented from rotating .by .pawls J0, .as clearly shown in the diagram of Fig. 4. 0n the other hand, pawl J18, pushed by rod ll, actuates lever 13 which raises block 16 against the action of spring I1. The upper sheet of the pile is therefore no longer maintained and, under the action of roller .9, .it is .locally displaced, i. e. its

' blocks.

known, such a kind of buckle will easily separate two sheets stuck together; thus, if the second sheet of the pile was displacedtogether with the.

upper one, it would be soon disengaged therefrom and would resume its original position owing to its elasticity. h

Towards the end of the stroke of rod II to the right of Fig. 1, pawl 18 reaches'abutment 20, as shown in Fig. 8; it is therefore raised and lever i3 is freed (Fig. 9), whereby block I6:is

again, pressed downwardly by spring l1. But

since the upper sheet has been locally displaced, block i6 now presses against the second sheet of the pile, as shown in Fig, 6.

During the return stroke of rod ll, rollers 9 move to the right, but this time they are not prevented from rotating by pawl l and they roll v on the sheets without displacing them (Fig; 7) 7 The sheet-feeding mechanism then begins its operation. It drags the upper sheet but cannot move the next one which is retained by the pressure of block I 6. V

At the end of the return stroke of rod ll pawl I8 is returned in front of the upper end of arm l3 as shown in Fig. 1. v When the pre-selector is disposed along one of thel'ongitudinal sides of the pile of sheets, block 16' may be dispensed with, the second sheet being retained by rollers 9 themselves. Considrlngfor instance Fig. '7 and supposing that the direction of the feed is perpendicular to the plane of the drawing, it is apparent that the second sheet will be retained against being carried along together with the upper one even if block I6 were omitted since the feeding motion is parallel to the axis of rollers 9 which therefore act as fixed The modification shown in Fig. 10 is also adapted for being placed along one of the longitudinal sides of the pile of sheets. In this case there is provided but one roller which is directly pivoted on the carriage '5 itself. Rod ll drives a lever '23 loose on the shaft 24 of the roller 25 and the latter is formed with a lateral toothed .portion actuated by a pawl 26 carried by lever 23. Roller 25 displaces the sheets 2 in succession and, with an appropriate adjustment, there can be obtained that only the upper sheet be cleared from' the roller at each stroke of rod H the second sheet being retained under the roller, by

. thepressure of the same, against being carried with the upper one since the motion of the latter is parallel to the aXis'of the roller.

f 1 I claim:

" 1. A pre-selector for the sheet-feeding mechanism ofstenciling machines and the like whereinfsheets are fed from a pile of sheets, said pre-selector comprising in combination avertically sliding carriage in the vicinity of the pile of sh'eetspa' spring-pressed block carried by said of sheets; pawl-and-ratchet means to unidirectionally prevent said roller from rotating when pushed towards the center of the pile of sheets; means to reciprocate said lever so as to locally displace the first sheet of said pile previously to the action of the sheet-feeding mechanism; means connecting said reciprocating means with said block to lift the latter from the pile when said first sheet begins being displaced, said connecting means including a disengageable pawl; and an abutment supported by said carriage to disengage said disengageable pawl substantially at the end of the active stroke of said lever so as to cause said block to press on the second sheet of said pile before said sheet feeding mechanism begins to operate.

2. A.,,pre-selector.for the sheet-feeding mechanism of stenciling machines and the like wherein sheets are fed from a pile of sheets, said preselector comprising a roller resting on the pile of sheets near an edge thereof, said roller having its axis parallel to the direction of the feed of said sheets; and means to rotate said roller for a limited angle previously to the action of the sheet-feeding mechanism on the first sheet of the 2 pile so as to locally displace said first sheet and to bring said roller into contact with the second sheet to retain the latter during the next sheetfeeding operation.

3. A pre-selector for the sheet-feeding mechanism of stenciling machines and the like in which sheets are fed in succession. from a pile of sheets, said pre-selector comprising in combination a vertically freely movable supporting carriage; sheet-buckling means carried by said carriage and pressed on said pile by the weight of said carriage irrespective of the height of the top sheet; and means on said carriage to actuate said sheet-buckling means. Y

4. A pre-selector for the sheet-feeding mecha- 40 nism of stenciling machines and the like in which sheets are fed in succession from a pile of sheets, said pre-selector comprising in combination a vertically freely movable supporting carriage; a M roller pivoted on said carriage and resting on said pile and pressed thereon by the weight of said carriage irrespective of the height of the top sheet, said roller having its axis parallel to the direction of feed of the sheets; and means to rotate said roller for a limited angle previously to the action of the sheet-feeding mechanism on the top sheet so as to locally displace said first sheet and to bring said roller into engagement with the second sheet to retain the same.

5. A pre-selector for the sheet-feeding mechanism of stenciling machines and the like in which sheets are fed in succession from a pile of sheets, said pre-selector comprising in combination a vertically freely movable supporting carriage; a reciprocatable sheet-buckling roller pressed on said pile by the weight of said carriage irrespective of the height of the top sheet, said roller having its axis parallel to the direction of feed of the sheets; pawl-and-ratchet mechanism to prevent said roller from rotating during its sheet-buckling stroke; and means on said carriage to reciprocate said roller.

6. A pre-selector for the sheet-feeding mechanism of stenciling machines and the like in which sheets are fed in succession from a pile of sheets, said pre-selector comprising in combination a vertically freely movable supporting carriage; a substantially vertical oscillatable lever pivotally supported by said carriage; a sheetbuckling roller pivoted at the lower end of said lever, said roller being pressed on said pile by the weight of said carriage irrespective of the height of the top sheet; pawl-and-ratchet mechanism to prevent said roller from rotating during its sheet-buckling stroke; and means to oscillate said lever.

7. A pre-selector for the sheet-feeding mechanism of stenciling machines and the like in which sheets are fed in succession from a pile of sheets, said pre-selector comprising in combination a vertically freely movable supporting carriage; a substantially vertical oscillatable lever pivotally supported by said carriage; a sheetbuckling roller pivoted at the lower end of said lever, said roller being pressed on said pile by the weight of said carriage irrespective of the height of the top sheet; pawl-and-ratchet mechanism to prevent said roller from rotating during its sheet-buckling stroke; retaining means supported by said carriage to retain the second sheet of the pile when cleared from the top sheet; means to oscillate said lever; and means on said carriage to actuate said retaining means.

8. A pre-selector for the sheet-feeding mechanism of stenciling machines and the like in which sheets are fed in succession from a pile of sheets, said pre-selector comprising in combination a vertically freely movable supporting carriage; a substantially vertical oscillatable lever pivotally supported by said carriage; a sheetbuckling roller pivoted at the lower end of said lever, said roller being pressed on said pile by the weight of said carriage irrespective of the height of the top sheet; pawl-and-ratchet mechanism to prevent said roller from rotating during its sheet-buckling stroke; means to oscillate said lever; a spring-pressed block carried by said carriage and adapted to be vertically pressed on said pile; means connecting said lever with said spring-pressed block so as to lift the latter from the pile during the sheet-buckling stroke of said roller, said connecting means including a disengageable pawl; and an abutment supported by said carriage to disengage said pawl substantially at the end of the sheet-buckling stroke of said roller.

9. In a combination as set forth in claim 8, said connecting means comprising a pawl pivoted at the upper end of said lever; a two-armed lever pivoted on said carriage, one arm of said twoarmed lever having its end engaged by said pawl and the other arm of said two-armed lever being substantially horizontal; and a vertical rod fixed to said block and pivoted at the end of said last-named arm.

10. A pre-selector for the sheet-feeding mechanism of stenciling machines and the like in which sheets are fed in succession from a pile of sheets, said pre-selector comprising in combination a reciprocatable roller in continuous engagement with the pile of sheets irrespective of the height of the top sheet thereof; pawl-and-ratchet mechanism to prevent said roller from rotating during its sheet-buckling stroke; and means to reciprocate said roller.

AIME ARMAND ROY.