GB2082506A - Book cover feed apparatus - Google Patents

Abstract

Apparatus for feeding book covers (6) to book blocks (2) conveyed at uniform intervals by, for example, a plate chain (1) comprises a conveyor for supplying the covers to the book blocks individually and successively by means of entrainment devices (5), the conveyor being disposed along the book block conveying path. The entrainment devices (5) are fixed to conveying chains (4) and are each disposed at a certain distance (Y) from the rear edge (7) of a respective book cover (2) to be covered. At least one measuring device (8) for measuring the relevant distance (Y) is disposed on the route to be travelled by the book blocks (2) and covers (6) and influences, via an evaluating device, a correction drive, preferably a stepping motor. <IMAGE>

Description

SPECIFICATION Book cover feed apparatus The present invention relates to apparatus for feeding book covers to uncovered book blocks conveyed at uniform intervals along a conveying path by, for example, a plate chain conveyor.

It is known from DD-PS 44588 to supply covers, via a pair of conveyor chains with entrainment means mounted thereon, to book blocks and to feed the covers onto the book blocks via a combined crank and cam drive.

The entrainment devices of the transfer arm here temporarily move at a higher speed than the book blocks, in order to assimilate the position of the cover to that of the book block, and remain firmly in contact with the book block during the feed operation. In this construction it is a particular disadvantage that the large masses of the combined crank and cam drive must be repeatedly accelerated and decelerated, resulting in a marked limitation of cyclic operating speed.

A similar feed device is known from DE-OS 1 536 496, but this device also can be operated only at a relatively low working speed, so that the number of cycles of the bookbinding machine is kept to a relatively low limit.

In DE-OS 2640497 there is described a cover feeder device in which the cover is transported on a pair of conveyor chains on which entrainment devices are fitted, which each apply holding tongs to the book block as the cover is conducted up to the book block and thereby fit the cover to the block. The covers which follow the blocks must be accelerated many times over a fairly long path in order to overtake the blocks.

In this device also, it is a disadvantage that the drive mechanism for assimilating the position of the cover to that of the book block imposes a limitation on the cycle speed of the machine. A further disadvantage lies in the fact that due to the application of the entrainment devices to the tongs or the book block a resilient retardation of the entrainment devices must be provided to avoid damage to the machine and book blocks.

There is accordingly a need for book cover feed apparatus which allows a relatively high operating speed of an associated bookbinding machine, accompanied by a reduction in the mass of the drive means and avoidance of damage to the book blocks during feeding of the covers. Such apparatus should preferably therefore be capable of bringing the covers at any speeds into coincidence with, but without contacting, the book blocks, so that the covers can then be pressed against the blocks.

According to the present invention there is provided feed apparatus for feeding covers to uncovered book blocks conveyed at uniform intervals along a conveying path, the apparatus comprising conveyor means for so conveying covers parallel to such path that in use the trailing edge of each cover is initially displaced relative to that of a respective one of such book blocks, measuring means arranged to measure the distance between the trailing edges of each associated cover and book block, and conveying speed adjusting means to so vary the relationship of the conveying speeds of the covers and book blocks in dependence on the measured distance as to align each cover with the associated block.

Preferably, in a bookbinding machine, book blocks are conveyed at a constant distance from each other through processing stations by an appropriate carrier device, preferably a pair of plate chains. in a preferred embodiment of the invention there is arranged at a specific distance from this first conveying device the feed apparatus, which is provided at its end with a pressing-on element. A singling device of the apparatus supplies the covers individually and successively to the book blocks by way of the conveying means of the apparatus, the conveying means being disposed alongside the conveying path of first conveying device and comprising conveyor chains with entrainment means fixed thereto.

The entrainment means are so adjusted that during the conveying operation they are each at a specific distance from the rear edge of an associated book block and are so disposed that a contactless assimilation of the covers to the book blocks can be carried out. This distance should preferably be less than 1 2 mm. Along the route which is followed both by the book blocks and the covers there is arranged at least one measuring device, which is situated somewhat beneath the block path and separately therefrom, the or each measuring device serving to establish the accurate distance of each cover from the rear edge of the associated book block.The measurement result is supplied to an evaluating device, which according to the resultant requirements causes a correction drive, for example a stepping motor, to bring about the necessary coincidence between cover and block. Advantageously, the distance between cover and block is measured by an impulse count method and the counted pulses are transmitted to the stepping motor. This stepping motor actuates, via a pinion, a toothed segment mounted on an arm, so that the arm, which engages into a planet wheel unit, can act via this planet wheel unit on the drive of the conveyor chains. In this case, the normal drive is so influenced by the stepping motor that a temporary acceleration of the chains can take place and thus an assimilation of the covers to the book blocks.After the cover has been pressed onto the book block, the stepping motor runs back again at an arbitrarily chosen time and delays the chains again by the same amount, so that the preset distance of the entrainment means from the next book block edge is again obtained.

During normal conveying operation, the book block and cover are conveyed at the same speed. During the assimilation of the cover to the book block, the conveying chains are temporarily accelerated by the stepping motor in addition to the conveying speed, until the distance corresponding to the counted pulses has been travelled. After the coincidence of cover and book block, both the conveying devices again run at the same speed, which can also be maintained when the stepping motor has brought the conveying chains together with the entrainment means back to the starting position.

During the normal conveying operation, the arm is held stationary in order that the drive of the conveying chains can take place exclusively from a chain drive via a sprocket and gear unit and the planet wheel unit to a chain wheel drive shaft and thus to the conveying chains. Instead of a planet wheel drive, another form of combination gear (superposition gear) can be used.

An embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of book cover feed apparatus according to the said embodiment; Figure 2 is a plan view of the apparatus of Fig. 1; Figure 3 is a diagrammatic view of drive means for a conveyor of the apparatus of Fig.

1, showing the normal drive state; and Figure 4 is a view similar to that of Fig. 3 but showing the drive means in the phase of assimilation of the position of covers conveyed by the conveyor to the position of book blocks.

Referring now to the drawings, there is shown part of a bookbinding machine comprising a plate chain conveyor 1 in which book blocks 2 are clamped at a uniform distance X and conveyed according to Fig. 1 in the direction of the arrow along a first conveying path at a constant speed. The back 3 of each book block 2 faces downwards and is processed in a working station (not shown) and coated with glue.

Below the plate chain conveyor 1 two endless conveyor chains 4 with entraining devices 5 mounted thereto are provided to define a second conveying path, these chains revolving at the same speed as the conveyor 1. Covers 6, which are supplied from a singling-out device (not shown), are conveyed on the chains 4 with their inner faces upwards. The entraining devices 5 push each cover 6 rest ing upon the conveying chains 4 at a distance Y, which is measured from the book block rear edge 7 by a measuring device 8, at the same speed as an associated book block 2 in the conveying direction.The measured distance Y, which advantageously should be less than 1 2mm, is electronically evaluated and converted by a drive unit, for example a stepping motor 9, into the required acceleration of the chains 4, and thus of the entraining devices 5, in order to overcome this distance Y and to assimilate the position of the cover 6 to the position of the book block 2. This assimilation takes place without contact between the cover and book block. After the rear edges of book block 2 and cover 6 coincide, the cover 6 is raised by a pressing element (not shown) and pressed onto the book block cover 3. By means of the stepping motor 9, a deceleration of the conveying chains 4 together with entrainment devices 5 is now carried out and thereby the intended trailing position of the entraining devices 5 behind the book block 2 is restored.

In Fig. 3, the device of the conveying chains 4 of the feeder apparatus during the normal transporting is illustrated diagrammatically. The drive transmission is effected from a drive unit in the direction of the arrow via a chain wheel 1 0, a drive chain 11, a chain wheel and pinion unit 1 2 and a planet wheel unit 1 3 to a wheel 1 5 firmly connected to a drive shaft 14, chain wheels 1 6 of the conveying chains 4 being fixedly mounted on the shaft 14. The planet wheel unit 1 3 is located by a lug or arm 1 7 which stationary during this movement phase, so that the planet wheel unit 1 3 functions solely as a drive transmission gear.A constant running speed of the conveying chains 4 together with entraining devices 5 thus results.

In Fig. 4 the same drive is illustrated diagrammatically, but the transmission is shown in the phase of assimilation of the position of a cover 6 to that of the associated book block rear edge 7. After the distance Y has been ascertained by the measuring device 8 and the stepping motor 9 has been loaded to a specific output by the electronic evaluating unit, the arm 1 7 is moved by the pinion 1 8 of the stepping motor 9 via a toothed segment 1 9 of the arm so that the planet wheel unit 1 3 rolls around the chain wheel and pinion unit 1 2 and thereby transmits the drive of the motor 9 via the driven wheel 1 5 and shaft 14 as an acceleration to the chain wheels 1 6 and thus to the conveying chains 4. When coincidence between the book block 2 and cover 6 has been achieved, the arm 1 7 is again arrested and further driving takes place as in Fig. 3. After the cover 6 has been pressed onto the back 3 of the book block, the starting position is again produced via the stepping motor 9 and the arm 17, the motor being driven in the reverse rotational direction.

Claims (9)

1. Feed apparatus for feeding covers to uncovered book blocks conveyed at uniform intervals along a conveying path, the apparatus comprising conveyor means for so conveying covers parallel to such path that in use the trailing edge of each cover is initially displaced relative to that of a respective one of such book blocks, measuring means arranged to measure the distance between the trailing edges of each associated cover and book block, and conveying speed adjusting means to so vary the relationship of the conveying speeds of the covers and book blocks in dependence on the measured distance as to align each cover with the associated block.

2. Apparatus as claimed in claim 1, the conveying means comprising conveyor chains equipped with entraining devices for entraining the covers at said trailing edges thereof.

3. Apparatus as claimed in either claim 1 or claim 2, comprising means for pressing the aligned covers against the associated book blocks.

4. Apparatus as claimed in any one of the preceding claims, the measuring means comprising at least one measuring device disposed at a respective measuring location on such path.

5. Apparatus as claimed in any one of the preceding claims, further comprising evaluating means for evaluating measurements obtained by the measuring means and for controlling the speed adjusting means.

6. Apparatus as claimed in any one of the preceding claims, the speed adjusting means comprising a stepping drive motor drivingly coupled to the conveying means.

7. Apparatus as claimed in claim 6 comprising a gear transmission for transmitting drive to the conveying means by way of a planet wheel, the stepping drive motor being drivingly engaged with a toothed element for so displacing the axis of the planet gear in the transmission as to selectively accelerate or decelerate the conveying means.

8. Apparatus as claimed in claim 7, wherein the toothed element comprises an arm provided with a segment gear drivably engaged by a pinion of the motor.

9. Feed apparatus for feeding covers to uncovered book blocks conveyed at uniform intervals along a conveying path, the apparatus being substantially as hereinbefore described with reference to the accompanying drawings.