US2658450A - Sheet delivery arrangement for hectographic copying machines - Google Patents

Description

Nov- 1 95 R. BROWN ET AL SHEET DELIVERY ARRANGEMENT FOR HECTOGRAPHIC COPYING MACHINES 2 Sheets-Sheet 1 Filed April 18, 1952 A/fornehf' NOV- 10, 1953 R. BROWN ET AL SHEET DELIVERY ARRANGEMENT FOR HECTOGRAPHIC COPYING MACHINES 2 Sheets-Sheet 2 Filed April 18, 1952 0 Z wt KW 5 @mH w m5 m M 2 Viv m n MMO 7d 8 A/ L latented Nov. 10, 1953 SHEET DELIVERY ARRANGEMENT Foa l-IECTOGRAPHIC COPYING MACHINES Roland Brown, London, and Leonard Herbert Neville Watton, New Malden, England, assignors to Block & Anderson Limited, London, England, a British company Application April 18, 1952, Serial No. 283,022

Claims priority, application Great Britain May 31, 1951 6 Claims.

This invention relates to sheet delivery arrangements for hectographic copying machines.

In such machines, in which the drum which carries the hectograph-ic master sheet to be copied is located above a pressure roller which causes the copy sheet damped with a solvent for the hectographic ink to be pressed against the master sheet, the printed copy sheet bears the copy on its upper surface as it emerges from between the printing couple constituted by master drum and pressure roller. If it is discharged into a delivery tray at the rear of the machine, the operator supervising the feed of copy sheets to the machine cannot in general inspect the copy sheets as they are delivered in order to verify that the copy is satisfactory. Consequently, various arrangements have :been proposed for delivering the individual sheets to a delivery tray at the front of the machine, each sheet being maintained with its copy-bearing face uppermost and being transferred from the rear of the machine to the front delivery tray along a path lying below the pressure roller. With such front delivery arrangement difiiculties are sometimes experienced when the sheets are short or are of varying length in the direction of travel through the printing couple, the leading edge of a sheet fouling the trailing edge of a preceding sheet or even passing beneath it so that orderly stacking is not achieved or else the stacked sheets are not in the order in which they Were printed. For many purposes this constitutes a very serious defect.

According to the present invention the printed sheets passing from the printing couple are stacked in the printing sequence on a table behind the printing couple and are retained and aligned by a gate extending between the said table and the printing couple.

The stack of sheets may be removed from the rear of the machine, but preferably the gate device is immediately in front of driven delivery rollers so that when the gate is withdrawn the entire stack slides into engagement with these rollers and is positively fed as a stack with all the leading edges in alignment into a front delivery tray along a path extending below the printing couple. The upper of the pair of driven delivery rollers may also serve to assist in the transport of the copy-bearing sheets from the printing couple to the upwardly inclined rear table, the bottom of the sheet resting on top of this upper roller during this operation.

An example of a sheet delivery arrangement according to the invention will now be described in more detail with reference to the accompanying drawings in which:

Fig. 1 is a diagram of part of a cross-section through a hectographic copying machine showing the relative disposition of the various components of the sheet delivery arrangement;

Fig. 2 is a diagram corresponding to that in Fi 1 but showing the mechanism in a different position;

Fig. 3 is a perspective view taken from the rear of the machine showing one assembly of upper and lower delivery rollers and a gate co-operating therewith, which may be used in the arrangement shown in Figs. 1 and 2; I

Fig. 4 is a part of a section taken in the same plane as Figs. 1 and 2 illustrating a modification wherein the upper delivery rollers assist in feeding the printed sheets to the stack.

In the description and drawings only those or the machine will be indicated which are essential for an understanding of the invention. As seen in the drawings, the right-hand side of the mahcine will be referred to as the oeprators side or the front, whilst the left-hand side Will be referred to as the rear of the machine.

Referring now to Figs. l and 2, i is the driven printing drum or cylinder of a hectographic copying machine which carries the hectographic master and masking sheet or sheets secured thereto in the known manner, and 2 is a counter-pressure roller movable With-respect to the cylinder to exert printing pressure thereon when the copy sheets are fed between the cylinder i and the counter pressure roller 2, these constituting What is known as the printing couple. The counter pressure roller may also be movable axially of the cylinder. The details of the printing couple and the mounting thereof are not shown since they form no part of the present invention. An example of a hectographic copying machine to which the arrangement of the present invention may be applied is shown and described in more detail in our co-pending application Serial No. 244,654. filed 31st August 1951.

liearwardly of the printing couple is arranged an assembly of sheet delivery rollers comprising upper rollers indicated generally by 3 and lower rollers indicated generally by t, these being carried on shafts it and ii respectively. The lower rollers d are rotated at constant speed in the direction indicated by belt and pulley gearing connecting one end .of shaft El? and a convenient point of the main power drive of the machine (not shown). The rollers 3 are friction driven from the rollers i, with which they are normally in contact, and, in order that a stack of printed copies may pass between rollers 3 and 4 without jamming, the upper rollers 3 are mounted to allow lifting movement thereof away from the rollers 4. For this purpose the shaft I6 is mounted at each end in arms pivoted to the side frames of the machine (not shown), these arms being substantially horizontal when the upper and lower rollers are in contact.

A gate consisting of a platform 5 carrying a series of upset fingers 6 (Fig. 3) spaced in a row parallel to the drum and immediately to the rear of the upper delivery rollers 3, is pivoted at each side in members of the machine frame (not shown) by means of a horizontal shaft 1. The pivoting motion of the gate may be manually controlled by the operator through a spring-urged push bar 8 pivoted at its rear end to a bracket 9 secured to the gate, and connected at its forward end to a foot pedal or hand lever (not shown), the bar 8 being movable between positions defined by a fixed pin 8a and a slot 8b.

An upwardly inclined stacking table It] is arranged at the rear side of the machine with its lower edge extending to a point closely adjacent the lower ends of the upstanding fingers 6 of the gate. The gate fingers and the delivery rollers are preferably constructed and arranged as shown in Fig. 3, wherein both the upper set of rollers 3 and the lower set of rollers 4, consist of axially spaced cylindrical sections 3a, 41; respectively, and the upstanding fingers 6 of the gate are spaced to coincide with the gaps between the sections 411 of the set of lower rollers. When the gate is pivoted downwardly about the horizontal axis of shaft 1 by the push bar 8 the in tervening fingers 6 of the gatemay pass downwardly through the gaps between the roller sections 4a, this position of the mechanism being shown in Fig. 2.

The operation of the sheet delivery arrangement is as follows: with the mechanism in the normal working position as in Fig. 1, the copy sheets are fed in the normal manner to the printing couple and are delivered rearwardly, with their freshly printed surfaces uppermost, in a substantially horizontal direction, to pass over the top of the delivery rollers 3 and over the top of the gate and are deposited in the printing sequence in a stack H on the upwardly inclined table II], the lower horizontal edges of the stack ll being aligned by resting against the fingers 6 of the gate. As is known the sheets have a sufficiently smooth surface to slide over each other into the stacking position by gravity only. In this position the most forward edge of the stack of delivered sheets is just clear of the upper rollers 3 and just above the level of the line of contact of the rollers 3 and 4. When all the desired impressions have been taken from the printing master, the push bar 8 is displaced rearwardly by the operator to drop the gate into the position shown in Fig. 2, allowing the stack of sheets H to enter the nip of the upper and lower delivery rollers and to lift the upper rollers 3 to allow the stack to pass therethrough. The stack is gripped thereby as a whole and transported forwardly in the direction shown in Fig. 2, whereupon it slides down an inclined tray l2 and is collected by the operator at the front of the machine. In order to give full support to the stack from below, the roller sections 4a are spaced apart by gaps as narrow as possible whilst allowing entry of the intervening fingers 6.

In the arrangement above described the sheets delivered from the printing couple may clear the top of the upper delivery rollers 3 when being fed over the gate on to the table III. Fig. 4 illustrates an arrangement in which the top delivery rollers 3 assist in transferring the delivered sheets to the stacking table. As shown the delivery rollers are arranged such that the periphery of the upper set of rollers 3 is slightly higher than the topmost edges of the fingers 6, and is in such a position with respect to the printing couple that the trailing portions of the delivered sheets 15 make contact with the upper rollers 3, and are thereby assisted in their rearward travel towards the table Ill. The speed of rotation of the delivery rollers 3 and 4 will therefore be determined by suitable choice of gearing with respect to the speed of rotation of the printing couple to ensure that the sheets have sufficient momentum to carry them over the uppermost edges of the fingers 6 but nevertheless to ensure an even stacking when the sheets arrive on the collecting table [0.

Although preferred arrangements of the mechanism have been above described, modifications thereof may be effected whilst maintaining the benefits of the invention. For example the particular arrangement of the sectioned upper delivery rollers 3a shown in the drawing is not the only one which is possible. Other axial spacings of the sectioned rollers may be adopted suited to the dimensions of the sheets or tickets to be printed by the machine, and the sets of sectioned rollers may accordingly be interchangeable.

We claim:

1. In a copying machine of the type comprising a rotary printing drum and a counterpres sure roller together forming a printing couple, the arrangement of sheet stacking means at the delivery side of the printing couple with means for returning the stack to the feeding side comprising a receiving table upwardly inclined from the rear side of the printing couple, a movable gate between the receiving table and the printing couple said gate having a normal position in which printed sheets are delivered singly over the gate and reverse their motion, due to the inclination of the table, to form a stack with edges abutting the gate, means for moving said gate to release the stack, and stack conveying means comprising driven rollers situated beneath the drum to impel the released stack toward the feeding side of the machine.

2. In a copyin machine of the type comprising a rotary printing drum and a counter-pressure roller together forming a printing couple, the arrangement of sheet stacking means at the delivery side of the printing couple with means for returning the stack to the feeding side comprising a movable gate at the rear side of the printing couple, said gate having a raised and a lowered position, a receiving table positioned at the rear side of said gate and upwardly inclined therefrom, said gate and table being so positioned that sheets are delivered in printing sequence over the raised gate and return down the table incline to form a stack with edges abutting the gate, means for lowering the gate to release the stack and means positioned below the drum to receive said stack and impel it bodily towards the feeding side of the machine.

3. The combination of sheet stacking and return feeding means according to claim 2 wherein the means for impelling the stack toward the feeding side of the machine comprises driven delivery rollers arranged between the gate and the feeding side of the machine and adapted to grip the stack when released by the gate and to feed it along a path below said printing couple towards the feeding side of the machine.

4. The sheet stacking and return feeding means according to claim 3 wherein the delivery rollers comprise upper and lower sets of rollers of which at least the lower set consists of axially spaced roller sections secured to a shaft, and the said gate comprises a number of fingers spaced to coincide with the gaps between the roller sections so that the said fingers intervene between the roller sections when the gate is lowered to present the stack to said delivery rollers.

5. The sheet stacking and return feeding means as claimed in claim 3, including a horizontal pivot shaft for said gate at the rearward side thereof and a bar for pivoting said gate about the axis of the pivot shaft, said bar being operable from the feeding side of the machine.

6. In a copying machine of the type comprising a rotary printing drum and a counter-pressure roller, the combination of sheet stacking means and stack returning means comprising a receiving table upwardly inclined from the rear side of the printing drum, a movable gate having a normally closed position at the foot of said receiving table to arrest and align sheets delivered over said gate on to the table in overlapping relation to each other and moving down said incline to form a stack, upper and lower delivery rollers positioned at the opposite side of said gate from the inclined table to receive the stack from said table when the gate is opened, means for rotating said delivery rollers in a direction to impel the stack bodily towards the feeding side of the machine, said upper rollers being positioned between said counter-pressure roller and the gate for assisting delivery of said sheets over the gate and on to the inclined table.

ROLAND BROWN. LEONARD HERBERT NEVILLE WATTON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 770,486 White Sept. 20, 1904 2,070,684 Ritzerfeld Feb. 16, 1937 2,220,283 Ritzerfeld Nov. 5, 1940 2,590,179 Johnson Mar. 25, 1952

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