GB2080773A - Collating machine - Google Patents

Abstract

A machine for collating printed sheets to form a brochure is provided with a series of feed stations arranged along a conveyor device, said stations each including a feeder (9) of printed sheets, a gripper drum (12) and a support table (13). To ensure accurate placing of the printed sheets on the support table (13) at high operating speeds of the machine, printed sheet guide means (35 to 44) are provided between each gripper drum (12) and its associated support table (13). <IMAGE>

Description

SPECIFICATION Collating machine This invention relates to a machine for collating printed sheets during the production of books, brochures and the like each of which comprises a plurality of said sheets.

It is known, for example from Swiss patent application no. 11823/78, to provide such machines which include a plurality of feed stations arranged along the length of a conveying device, each feed station having associated therewith a pile of printed sheets and a gripper drum for feeding the sheets sequentially from the pile onto an assdciated support table for subsequent transportation by the conveying device.

When operating at high working speeds and when processing lighter printed sheets, there is a danger that the printed sheets are not placed exactly in the required position on the support tables, which can lead to faults in that the printed sheets may become twisted as they are accelerated towards the conveyor device.

According to the present invention this disadvantage can be eliminated by further including in the machine guide means between each gripper drum and the associated support table for positive transfer of the sheets from the gripper drum onto said support table.

Preferably each guide means drives its associated printed sheets from the gripper drum to the support table at a speed equal to the rotational speed of the gripper drum. With such an arrangement the printed sheets, irrespectively of their air resistance, are transferred onto the support table without delay and in exact synchronism with the gripper drum.

Each printed sheet means may comprise an arrangement of endless belts the surfaces of which, in the region between the gripper drum and the support table, extend parallel with one another and are in contact with one another to drive between them the associated sheets, Such an arrangement enables the guide means to be of simple construction whilst producing an effective drive for the printed sheets in the region of the guide means.

Further, the speed of drive can readily be synchronised with the rotational speed of the gripper drum.

In a preferred machine, the driving surfaces of the endless belts, in the region between the gripper drum and the support table, extend substantially parallel with the supporting surface of the associated support table. As a result, instead of depositing the printed sheets on the support tables as in known machines, a sliding of the printed sheets onto the support tables occurs, resulting in correct positioning of the printed sheet on the support tables.

Conveniently one end of the region of drive of the endless belts between the gripper drum and the support table is defined buy a pulley adjacent the support table and about which one of said endless belt arrangements extends, said pulley being movable towards and away from said support table, while it is further preferred that the edge of each support table adjacent said pulley comprises an adjustable guide movable in the direction of movement of the pulley. Such arrangements make it possible to ensure accurate lateral guidance of the printed sheet, irrespective of its width, in the direction of conveyance of the conveying device, and to guide it away from the gripper drum as far as the support table irrespective of its width.

By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which: Figure 1 is a side view of a collating machine according to the invention; Figure 2 is a plan view from above of one of the feed stations of the machine of Figure 1 with the pile of sheets omitted for clarity, and Figure 3 is a section on the line Ill-Ill of Figure 2.

Referring to the drawings Figure 1 shows a collating machine including a conveyor chain 2 travelling in the direction of arrow A over return pulleys 1, and provided with a series of upstanding driver pins 3. The front, driven pulley 1 is mounted in a housing 4 which contains the drive motor 5 of the machine, which motor also drives a bevel gear 6 meshing with a bevel gear 7 secured on, to be rotatable with, a common drive shaft 8 for a series of feeders 9a, 9b, 9c spaced along the chain 2. The drive shaft 8 is located above the chain 2 and extends parallel with and the full length of said chain.

Above each feeder 9 is mounted a support arrangement for an associated pile Sa, Sb, Sc of mutually identical folded or unfolded paper sheets, said support arrangements being integral with the housing 4. Beneath the row of stacks S is mounted a suction tube 11 connected to a suction pipe 10, said tube 11 extending parallel to and above the drive shaft 8, and being rotatable about its longitudinal axis. Suction cups 11' are arranged on the suction tube 11 so that, on rotation of the suction tube 11, said cups bring the lowest paper sheet of a pile S into the region of an associated gripper drum 12.

The gripper drums 1 2a, 1 2b, 1 2c are continuously revolving, being secured on the drive shaft 8, said gripper drums serving to transfer the lowest sheet of a pile S from said pile onto an associated support table 13a, 13b, 13c. A slideway 14 is arranged between the support tables 13 and the conveyor chain 2, and consists of two parallel, spaced metal guides between which the driver pins 3 engage into the region of the support tables 13.

On each cycle of the machine, and at each feed station charged with a pile of printed sheets, a printed sheet is placed on the associated support table 13. The next driver pin 3 to arive pushes this printed sheet forwards whereby said sheet falls from the associated support table 13 towards the sliding surface 14 and is thereby laid on top of the packet of printed sheets already being pushed in front of the driver pin 3 on the slideway 14. At the end of the transport path, the packet P of printed sheets so collated and pushed in front of the driver pin 3 corresponds to a complete book or brochure. The slideway 14 includes an inclined metal guide and a horizontal metal guide separated by a slit 15, the horizontal guide being adjoined at right angles by a guide rail 16. The driver pins 3 move along the slit 15.

The gripper drums 12 (Figures 2 and 3) are constructed in manner known perse and are provided with grippers 17 which grip the downwardly hinged backfold of the lowest printed sheet on a pile Sand draw it out from the pile S.

The support table 13 consists ofthree parts, namely a lateral guide element 18 of acute-angled cross-section firmly connected to the guide rail 16, a support plate 19 and a second angle rail 20, iikewise acting as a lateral guide means. The angle rail 20 is arranged parallel to the lateral guide means 18 and is slidable towards and away from the latter and lockable in a given position, so that a printed sheet lying on the support table 13 is guided on its two longitudinal sides. To enable adjustment of the location of the angle piece 20, the support plate 19 has two lateral slots 21 formed therein, through each of which a screw 22 is passed to be screwed firmly into a corresponding screw-threaded bore formed in the support plate 19.

The support plate 19 itself is attached to two levers 24 mounted on a pivot axis 23, the top ends of said levers being firmly interconnected by an axis 25.

Two support arms 26 projecting above the support table 13 are attached to the axis 25 and each carry at theirfree end a gear housing 27 incorporating a helical gear. A toothed belt pulley 28 is mounted on, to be rotatable with, the drive shaft of the helical gear, while a rotating arm 29 is mounted on the output shaft from said gear. The two rotating arms 29 associated with each station are parallel, a bar-shaped holding down and accelerating element 30 being articulately connected to the free ends of said arms 29. The element 30 is a rubber bar of rectangular cross-section which provides a friction surface against the support table 13, the bar 30 extending parallel to the transport direction (arrow A) of the conveyor chain.

When the arms 29 rotate, the bar 30 moves in a circular orbit, and, in its position nearest to the support table 13, it has the same direction of movement as the conveyor chain 2, and preferably at least approximately the same speed as said chain.

A printed sheet lying on the support table 13 is thereby accelerated by the bar 30 to the speed of the conveyor chain 2 and is simultaneously pressed against the support table 13. The bar-shaped construction of the holding down and accelerating element 30 prevents any twisting of the printed sheets during the acceleration phase, thus permitting trouble-free engagement of the printed sheets by the driver 3.

Sliding rollers 31 are mounted for free rotation in the support table 13 opposite the bar 30 in its lowest position, thus reducing the friction of any printed sheet sliding on the support table 13, particularly when it is pressed against the supporttable 13 and the sliding rollers 31 by the bar 30.

One end of the axis 25 passes through a hole 32 in an associated bearing plate and is articulated to the piston rod of a pneumatic cylinder 33. In the event of a fault and by an appropriate loading of the pneumatic cylinder 33, the levers 24 together with the support table 13 are pivoted rearwardly out of the position shown in Figures 2 and 3, whereby the slideway 14 becomes easily accessible for eliminating the fault.

In order to drive the toothed belt pulleys 28, corresponding toothed belt pulleys 34 are mounted on, to be rotatable with, the drive shaft 8, said pulleys 34 being kinematically connected to the toothed belt pulleys 28 by toothed belts 35. This ensures that the bar 30 is driven in synchronism with the gripper drums 12. The toothed belts 35 are, at the same time and as will be detailed below, a component of a printed sheet guide means between the gripper drum 12 and the support table 13.

U-shaped grooves 36 are milled in opposed faces of the levers 24, a plate 37 being slidably mounted in said grooves. The position of a plate 37 can be modified by means of an adjusting device 38 which consists of a screw shank with counterthread and a central milled bead. The screwthreadied ends of the screw shank engage in corresponding screwthreaded bores on the lever 24 and on plate 37.

Return pulleys 39, 40 are mounted to be freely rotatably on the plate 37, and are respectively associated with return pulleys 41 on an axle 23 and return pulleys 42 on an axle 43. An endless belt 44 is passed round each of the pulleys 39 to 42, which belts are in frictional contact with the associated toothed belts 35 to be driven by said belts 35. The belts 35 and 44 form, between the toothed belt pulley 34 and the return pulley 42, a wedge shaped entry 45 for the printed sheets, and then form a printed sheet guide means as far as the return pulley 39 which is located immediately in front of the angle rail 20.

The printed sheets accepted by the gripper drum 12 are brought through the entry 45 between the belts 35 and 44 and released there by the grippers 17. The belts 35 and 44 guide the printed sheet to the support table 13 and slide it onto the latter, so that the sheet comes to lie with its two ends between the lateral guides means 18 and rail 20. The angle rail 20 is adjusted so that its effective distance from the lateral guide means 18 corresponds to the width of the printed sheet.

During the sliding of the printed sheet onto the support table 13, the bar 30 is located at a sufficient distance from the former and comes into contact with the printed sheet just in front of the next driver 3: to arrive, in order to accelerate the sheet to the speed of the driver. During the pushing down of the printed sheet from the support table 13 by the driver3 onto the packet P of the printed sheets being pushed in front of the latter, the printed sheet is guided between the lateral guides 18 and 20, whereby any twisting of the printed sheet is prevented even at a high speed of the conveyor chain.

Claims (7)

1. A machine for collating printed sheets, the machine comprising a plurality of feed stations arranged along the length of a conveying device, each feed station having associated therewith a pile of printed sheets and a gripper drum at each station for feeding the sheets seqpendally frar.rl Jo onto an associated support table, the sheets being transported from the support tables onto said conveying device, the machine further comprising guide means between each gripper drum and the associated support table for positive transfer of the sheets from the gripper drum onto said support table.

2. A machine as claimed in claim 1 in which each guide means drives the associated printed sheets from the gripper drum to the support table at a speed equal to the rotational speed of said gripper drum.

3. A machine as claimed in claim 1 or claim 2 in which each guide means comprises arrangements of endless belts the surfaces of which, in the region between the gripper drum and the support table, extend parallel with one another and are in contact with one another to drive between them the associated sheets.

4. A machine as claimed in claim 3 in which, in said region between the gripper drum and the support table, the driving surfaces of the endless belts extend substantially parallel with the support ing surface of the associated support table.

5. A machine as claimed in claim 3 or claim 4 in which one end of the region of drive of the endless belts between the gripper drum and the support table is defined by a pulley adjacent the support table and about which one of said endless belt arrangements extends, said pulley being movable towards and away from said support table.

6. A machine as claimed in claim 5 in which the edge of each support table adjacent said pulley comprises an adjustable guide movable in the direction of movement of the pulley.

7. A machine for collating printed sheets substantially as described with reference to and as illustrated by the accompanying drawings.