US2393614A - Sheet feeding mechanism - Google Patents

Description

BY FeANuJN E. Cams Jan.v 29,1946.,

F. E. CURTIS 2,393,614

SHEET FEEDING MECHANISM Filed Feb. 8, 1941 `4 Shets-Sheet 2 Jan. 29, 1946. F. E. CURTIS '2,393,614

SHEET FEEDING MECHANISM Filed Feb. 8, 1941 v 4 Sheets-Sheet 5 l" sa 2.27

Jan. 29, 1946. F. E. CURTIS SHEET FEEDING MECHANISM Filed Feb. 8, 1941 4 4Sheets-Shawl'. 4

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uw wz INVENTOR. FWN/mf i. Caer/.5 BY 34%, w/ vfyfm Patented Jan. 29, 1946 UNITED STATES Pii'rislv'r` oFFlcE SHEET FEEDING MECHANISM Franklin E. Curtis, Willoughby, Ohio, assigner to Addressograph-Multigraph Corporation, Cleveland, Ohio, a corporation of Delaware Application February 8, 1941, Serial No. 378,034

Claims. (Cl. 209-88) y lThis invention relates to improvements in sheet delivery mechanisms, and is especially concerned l with improvements in and relating to sheet feeding mechanisms which are especially adapted to feed sheets one at a time to another mechanism, such as a printing or duplicating machine.

The general object of the present invention is to provide an improved sheet feeding mechanism` which will remove sheets one at a time from the top of a stack orl pile of sheets and deliver them to and in `timed relationship with another mechanism, such as a printing machine.

Another object of the present invention is to provide an improved sheet feeding mechanism, which will effectively feed sheets from a stack to a printing machine at a relatively high rate of speed and at` the same time prevent superposed sheets from reaching the printing ma.

chine.

Another further object ci' the invention is to provide an improved sheet detecting and diverting mechanism for a sheet feeder which mecha nism will detect the presence of superposed sheets and divert such sheets from the normal path of sheet delivery. v

i Other objectsv and features of this invention will become more apparent from the following description, reference being had to the accompanying drawings in which there is illustrated a preferred embodiment of the invention. The essential features of the invention will be summarized in the claims.

In the drawings, Fig. i is a plan partly broken away of a machine for separating and delivering sheets from the top of the stack thereof, incorporating the mechanism of this invention for preventing the delivery of multiple sheets; Fig. 2 is an enlarged sectional view of the sheet separating and feedingmechanism; Fig. 3 is an enlarged sectional detail of the sheet separating mechanism; Fig. 4 is a sectional detail of a sheet defiector; Fig. 5 is an enlarged sectional detail of a sheet detector or gauge unit, the plane of the section being indicated by the line 5-5 on Fig. 6; Fig. 6 is a front elevation of the unit illustrated in Fig. 5; Fig. 'i is a horizontal sectional detail as indicated by the lines l--l on Fig. 5.

Referring now to the drawings, wherein there is illustrated a -preferred form of the invention, and particularly to Figs. 1 and 2, there .is shown a portion ofthe general framev of a paper feeding suitable cross bars hereinafter mentioned. This frame carries a suitable sheet separating device which separates the top sheet from the pile and progresses it to suitable delivery means from which it may pass to av printing machine not shown.` y

The present inventionl is especially concerned with a detector unit indicated generally at t8 coacting with one of the feed rolls and controlling the operation of a defiector plate I9 which intercepts and diverts superposed sheets before they reach the delivery tapes which may lead to a printing machine. Such printing machine may be of any suitable form and may be located and connected as shown in my Patent 2,293,046, issued August 18, 1942, to my assignee Address@- graph-Multigraph Corporation, as a division of the present application.

, The paper table which supports a pile or stack of sheets W to be fed, is illustrated in Figs. 1 and 2. placed on a table 45, with its forward corners seated in vertically extending guides M which.

are adjustable transversely. The paper table d5 is slidably mounted for vertical movement in the frame l0, the arrangement being such that the table may .be raised-at periodic intervals to maintain the uppermost sheet in the stack substantially in a predetermined plane where itvmay be conveniently engaged by the sheet separating mechanism hereinafter to be more fully described.

The paper table d5 is shown as provided with a pair of side flanges it, each of which carries a pair of rollers il. These rollers project out--v wardly from the sides of the table l5 and engage the flanges'f of vertically extending channels it carried by the frame i\l,'thus guiding the table for vertical movement.

The table d5 is supported by a pair of chains,

one of which is shown at in Fig. 2. These chains are attached to respective side flanges i6 of the table d5 as at 5|, and extend upward to respective sprocket wheels 52 and thence downward. Counterweights 55 are secured to the depending free ends of each chain. The sprocket wheels 52 are secured to a cross shaft 56 which is journaled in the side plates El supported by machine having my invention. The frame portion shown comprises a suitable support I0 and the frame l0. This shaft is operated by any suitable mechanism to move the table and retain it in an adjusted position.

The paper table 45 is periodically raised by power mechanism actuating the shaft 56. The operation of this power mechanism is controlled by the location of the top of the stack. This is. I

As there shown, the stack of sheets W is t eifected through the instrumentality of a bail 10 resting on the top of the stack and adapted whenever ,the bail descends a predetermined amount to initiate the raising mechanism. Any suitable mechanism may be employed for this purpose, for instance, that shown in my prior Patent 2,358,560, granted September 19, 1944, to my assignee Addressograph-Multigraph Corporation as a division of this application. It may be noted also that in practice the bail 10 is suitably linked with the printing mechanism to which the paper is fed so that the bail may be periodically moved out of contact with the top sheet preceding the feeding of such sheets The sheet separating and feeding mechanisms which are best illustrated in Figs. 2 and 3, will now be described. The separation of the top sheet W from the stack is accomplished by a` suction foot IIII. This foot is lowered into contact with the top sheet, suction applied, drawing the sheet into contact with the lower end of the foot, whereupon the foot is raised, moving a short distance rearwardly while raising, and then moved in a substantially forward direction to insert the separated sheet between feed rolls |I| and ||2. As lthe sheet is inserted into the bite of these rolls, the suction is released and the rolls continue the feeding of the sheet. After the rolls have completed the feeding of the sheet, the suction foot II8 is lowered into contact with the next sheet on the stack and the cycle of operation is repeated.h

The suction foot III) comprises a hollow casting, the lower end of which is open, and the upper end of which is connected by a flexible conduit ||5 and other means hereinafter to be described as a motor driven vacuum pump. not shown. This foot ||0 is adjustably secured to a shaft ||8 by a set screw I I1 to facilitate adiustment transversely oi' the feeding mechanism.

The suction foot is operated in timed relation with the printing machine. As illustrated in Fig. 2, ,the shaft at ||8 carrying the suction foot is journalled at its ends in a pair of cross arms ||3 which are secured to a cross shaft 8 rotatably mounted in the side plates 51. As illustrated in Fig. 3, the shaft ||8 has secured to its outer end a depending lever ||9 and this lever may be suitably linked with the printing machine.

The rocking of the lever I9, thus results in the rocking of the shaft I I8 and imparts a rocking movement to the foot carrying shaft I I5. As heretofore mentioned, the suction foot first raises, moving slightly rearwardly as it does, and then swings forward to move the -sheet to the bite of the feed rolls I| I and ||2. This operation and movement is best illustrated in Fig. 3. As there shown, an arm |25 is secured to the foot carrying shaft IIS and is provided at its lower end with a roller |26 which is drawn by a spring |28 into engagement with a guide plate |21 secured to a side rplate 51. This guide plate (Fig. 3) inclines upwardly and rearwardly so that as the shaft I I8 and arms ||3 rock in a clockwise direction (Fig. 3) the lower end of the suction foot moves upward and rearward, as indicated ing one or more fiat spring lingers |35. This iinv ger or fingers are adjustably positioned on the bar |35 by 'adjusting screw |58. Each finger |38 is normally spaced a predetermined distance above the uppermost sheet W of the stack and above the lowermost position of the sheet engagby the progressive series of dotted lines |29..

ing the bottom surface of the suction foot. It will be noted from Fig. 3, that these spring flngers project inwardly above the stack', but a comparatively short distance, hence, as the suction foot raises a sheet W from the stack, the innermost end of the sheet is drawn with a wiping motion past the end of the finger. Should two or more sheets tend to yraise with the suction foot, this wiping movement generally causes all but the top sheet to return to the stack.

A suitable motor driven pump not shown provides the suction supply for the foot IIII. The suction side 0f the pump is connected with a valve |45 by a conduit |44. The valve is connected with the suction foot by the flexible conduit I5. Th suction foot ||8 is controlled by opening the valve I45 to atmospheric pressure. The valve |45 is best shown in Fig. 2, and comrprises a valve body having a through passageway |48, the opposite ends of which are in communi- .cation with the conduits I5 and |44 respectively.

Intermediate its ends the valve body is provided with a port |41, which when closed, brings the suction side of the pump into direct communication with the suction foot III). However, when this port is opened, the suction to the foot is broken by atmospheric pressure entering the port. The valve port |41 is opened and closed in timed relationship with the operation of the suction foot I| 0. Pivoted to the body of the valve |45 is a lever |48 which carries a closure |45 for the port |41. A spring |50 normally retains the closure seated against the valve rport. In Fig. 2, the parts are shown in the positions they assume immediately after the closing of the valve port to apply suction tothe foot ||8. It will be remembered that the foot is raised and swung forward by the clockwise rotation of the shaft III. Secured to this shaft is a lever |5| having an inwardly extending portion |52 which carries an adjustable screw I 53 and a contacter |54. As the shaft ||8 swingsto cause a sheet to be fed, the lever |5| swings toward the upper end of the valve lever |48, and as the feed rolls I and |I2 grip the sheet, the screw |53 contacts the lever |48. opening the port |41 and causing the sheet to be released from the suction foot.

When the valve closure lever |48 moves to open the valve port, a pin |55 carried thereby engages and cams upward one arm of a bell crank |58. A spring |51, interposed between the bell crank and a frame plate 51 then causes a latch .portion |58 of the bell crank to engage the pin |55 and retain the valve closure |48 in an open position. On the return stroke of the foot III), the swinging of the shaft ||8 in a counter-clockwise direction, then causes the contactor |54 of the lever I5| to engage an adjustable screw |58 on vthe upper arm of the bell crank I 58, and moves returning the partsy to the position iuustrated in Fig. 2.

, The pressure side of the pump 4is connected by a pair of conduits IBI to respective Jets |80 disposed at opposite sides of the stack of sheets. As shown in Fig. 2, these jets direct air under pres- `suretoward the sides of the uppermost sheets in the stack. The iets are positioned adjacent the forward edges of the stack and direct blasts of air beneath the forward portion of each sheet g while it is being lifted by the suction foot.

Despite the precautions taken and the high eiiiciency of the sheet separating mechanisms above described as compared with sheet separatm ing and feeding mechanisms now in use, it has been found that climatic conditions and other factors, particularly irregularities, blemishes or semi-porous condition of the paper sheets themi selves, sometimes causes more than one sheet to be fed at a time. 'This has numerous disadvantages too well known in thevprinting art torequire enumeration here. To'prevent the delivery to the printing machine oi superposed sheets, a gauge I8 is provided to control the operation of a diverter I9 which diverts superposed sheets from the sheet delivery mechanism as heretofore meni tioned.

As shown, the gauge comprises a carriage iid mounted for axial adjustment on a rod I it which extends between the side plates 5i. The lower end of the carriage is positioned by a second rod |11 similarly mounted in the side plates iii. The gauging member comprises a. roller Itii rotatably mounted by means of anti-friction bearings iti on a spindle |19 which is secured to and mounted between a pair of arms |02. These arms are pivotally mounted on the lower end of a bracket itt,

carried by the arms |82. An adjusting screw itt;

carried by the bracket engages the pin it in a. region diametrically opposite the plunger. In this way, any lost motion in the switch mechanism or between the plunger and its contacter is controlled.

In operation, the carriage |10 is adjusted axially of the rod |16 and secured in position by a set screw |89. The bracket |88 is then adjusted ventically to position the gauge roller |80 so that itY contacts a single'Y sheet. The adjusting screw |88 is set to permit contact between the roller and the single sheet without causing theV operation of the switch mechanism. However, when more than one sheet passes between the gauge roller and the lower feed roll III, the arms |82 rock about their pivot |90 and the pin |81 actuates the switch mechanism.

It will benoted from Fig. 5, that the gauge roller contacts the sheets forward of a line intersecting the axes of the feed rolls III and II2. This has a decided advantage in that it compensates for slight variations in the thickness of the sheets. By placing the gauge roller in advance of the feed rolls, any-buckling of the sheet, which sometimes occurs immediately after the sheet leaves such rolls, cannot affect the gauge mechanism and cause the diversion of the sheet. It has been found expedient in sheet feeding mechanisms of this general type to have the upper feed roll comprise a series of axially spaced rolls. Again, .by positioning the gauge roll in advance of these upper feed rolls, buckling of the sheet between these rolls does not ailect the gauge mechanism. This feature is especially advantageous when comparatively thin sheets, such as tissues, are being fed. f Vertical adjustment of the gauge roller to com- Pensate for sheets of dierent thickness is made by moving the bracket itt vertically in the car-B riage |10. The bracket is slidably mounted for vertical movement in ways |92 formed in the carriage, and is supported by a plunger i90 secured to the bracket by a nut iii and which is slidable in a verti extending bore itt in the carriage. A imurled adjusting screw itt passing through an cpeg in the top oi the .carriage threadingly engages the plunger and prpvides for its vertical adjustment -A compression spring itl, interposed between the upper end of the plunger and the top oi the carriage; maintains the bracket in its lowered position and prevents damage to the mechanism.v A leaf spring i dit engages the imurled head oi' the screw and maintains it in an adjusted position. i The upper feed rolls iii are likewise adjustable for sheets oi did'erent thicimess. As heretofore mentioned, these rolls are rotatably mounted on a shaft 2id. shaft (Fig. 3) is mounted between a pair oi arms tdi which are pivotally mounted on a cross trame shaft titi. Secured to each arm dit, as at ddd, is an. upwardly extending threaded stud itt, which'passes freely through a block 2M, carried by the adjacent side plate iii, and which is engaged at its upper end by a miurled nut ttt. A compression spring dit, interposed between an abutment iti on. the stud and the lower face of the block tti, resiliently maintains the arm in its lowermost position and prevents damage to the parts.

The feed rollers iii and iii are continuously rotated in the direction to feed the sheet forwardly by suitable means operating in timed relation 'with the printing machine.

The feed rolls iii and i Ware preferably driven in timed relation with the printing machine. As indicated in Figs. l and 2, a driving belt iti extends from a suitable motor driven sheave not shown over a pulley it (Figs. 1 and 2) on the `shaft |66 of the roller 220 oi' the delivery mech- `anism hereinafter more fully described. A second sheave |65 is also tight on the shaft it. A second drive belt iti interconnects a sheave |65 with a sheave iti which is drivingly secured to the lower feed roll il i in the usual manner.

As heretofore mentioned, the detector mechanism I8 actuates a diverter plate I9 which diverts superposed sheets from the normal path of sheet travel. The sheets W as they leave the feed rolls I ii and I I2, normally travel in a horizontal plate to a set of advancing rolls 220 and 22 I, of the delivery mechanism.v A table 222-223 bridges the gap between the two sets of rolls. The section 223 of this table is pivotally mounted, as at 220, to the side frameplates 51, while the section 222 is permanently secured to such side plates.

When the switch |84 of the gauge mechanism is energizeddue to the detection of the superposed sheets, it completes an electrical circuit which energizes a solenoid 225, shown in Fig. 4.'

The movable core 228 of this solenoid is connected by a link 221 with a iianged end oi' the diverter plate 222, as indicated at 228. The arrangement is such that the energization oi' the solenoid 225 rocks the diverter plate 222 into the position indicated' by the dotted lines on Fig. 4, against the action of a spring 229. The superposed sheets, traveling in the direction of thearrow shown in Fig. 4, then pass beneath the raised end 230 of the diverter plates 223, and are diverteddownward beneath the roll 220 into a suitable receptacle, indicated at 235 in Fig. 2.

When the diverter trip plate 223 is moved to the dotted line position shown in Fig. 4, it is latched in such position for the remaining portion of that cycle of operation of the feeding and separating mechanism. As the diverter plate rocks, a pin 23 carried thereby moves to the dotted line position shown in Fig. 4. The movement of the pin cams a pivoted latch 232 outward until the pin passes above the latch, whereupon a-spring 233 draws the latch into the position tshown in full line beneath the dotted line position of the pin 23H, retaining the deflected plate 223 in its swing position. The diverter plate is pivotally mounted at 22e and is released at the end of the cycle of operation and returned to its normal position by the spring 229.

It will be noted that the various feed rolls and associated mechanisms are arranged'to facilitate the feeding of either relatively long or short sheets. It will also be noted that the feed rolls iii, H2, the detector unit iii, the diverter mechanism itand the rolls 220, 22i of the delivery mechanism are compactly arranged. This arrangement enables the feeding of comparatively short sheets, as for instance, postal cards and the like to the printing machine at high rates of speed. 4

To insure the ejection of short sheets which are diverted due to the action of the detector mechanism, a supplemental feed roll 3i@ is rotatably mounted in the side plates 5l and surmounted by a pressure roller Sit. This feed roll is driven by the belt |62 heretofore described.

The feed roll 3|!) venables the positioning of the diverter plate 222 some distance away from the main feed rolls i i i, H2 and the detector unit rcller itil, thus permitting the sheet to travel a short distance before reaching the diverter plate 222. This compensates for the time lag in the operation of the diverter plate and thereby permits the operation of the feeding mechanism at relatively high rates of speed without detracting from the effectiveness of the sheet diverting mechanism. f

Figs. 1 and 2 disclose a portion of a sheet delivery mechanism for advancing the sheets which in the normal operation are fed horizontally across the diverting gate. This mechanism includes a plurality of flexible endless-tapes 240, extending about the constantly driven roller 220.

As a sheet progresses across the tables 222 and 223, it passes onto the tapes 240 and is retained in contact with the tapes by a plurality of rolls 22! heretofore mentioned. The rolls are best illustrated in Fig. 1, and are rotatably mounted on a shaft 245 carried between a pair of 'arms `24S, which are pivoted on a bar 241', extending between the side plates 51. If desired, suitable lightweight spring guides 249 mounted on the rod 247 may be used to guide the sheets into the bite of the rolls 220and 22|.

I claim:

aaneen 1. In a sheet feeding mechanism, the combination of a pair of feed rolls, to and from which the sheets may be fed one at a time, means for diverting a sheet if two are fed. at a time including a detector to detect the passage of multiple sheets, a switch to control the diverting means and itself controlled by the detector, means for adjusting the relation of the detector to the switch, and means for adjusting the relation of the detector to the sheet without changving the adjustment between the detector and the switch.

2. In a sheet feeding mechanism, a -feed roll, means to feed sheets one at a time to said roll,

' a detector to detect the passage, of superposed sheetsV to said roll, said detector comprising a body, a bracket mounted on said body and adjustable toward or from the path of the sheets, an electric switch carried by said bracket, an operating member therefor, carried by the bracket and comprising a bell crank, one arm of which coacts with said switch, a sheet contacting roller carried by the other arm of said bell crank and coacting with the feed roll to gauge the thickness of the sheet passing therebetweenand means responsive to action of the switch consequent upon the passage of super- 4 posed sheets between the roller and the feed roll Sti to divert such superposed sheets from the normal path of travel of single sheets.

3. In a sheet feeding mechanism, the combination of a pair of feed rolls, means to feed sheets one at a time to and from the bite of the feed rolls, means for diverting a sheet if two are fed at a time including a detector adapted to coact with one of the feed rolls and be moved by the passage of multiple sheets, a bracket carrying the detector, means for adjusting the bracket, a switch carried by the bracket and adapted to control the diverting means, and means mounted on the bracket for adjusting the relation of the detector to the switch, whereby the relation of the detector to the cooperative feed roll may be changed without changing the adjustment of the detector and the switch.

4. A gauge device for a sheet feeding mechanism comprising a body provided with a vertically extending guideway, a bracket movable along the guideway, means to adjustably limit the downward movement of the bracket in the guideway, resilient means between the bracket and the body to retain the bracket in its lowered position, an electric switch carried by said bracket, an operating member therefor, carlrieti by the bracket and comprising a bell crank,

one arm of which coacts with said switch, a sheet contacting roll carried by the other armof said y nation with a feed roll, of a support, a, bracket adjustably carried by the support', a lever mounted on the bracket, a roller carried by the lever and adapted to coact with the feed roll, a switch mounted on the bracket Iand controlled by the lever, and an adjustment for the switch mounted on the bracket, whereby the adjustment of theI bracket permits variable presentation of4 the detector roller to the feed roll without changing the adjustment of the switch. A

FRANKLIN E. CURTIS.

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