Priority is claimed to Swiss Patent Application No. CH 00575/11, filed on Mar. 30, 2011, the entire disclosure of which is hereby incorporated by reference herein.
The invention relates to a device and a method for delivering printed products from a saddle-shaped support.
Devices and methods of this type are known and are generally implemented in saddle stitchers. These are machines in which folded signatures are deposited on a saddle-shaped support in succession by a plurality of feeders, collated to form printed products, and bound. The printed products are subsequently passed to a means for further processing, for example a cutting device. In the saddle stitcher, at least in the region of the stitching means thereof, the signatures are often transported using what is known as a double collation chain, consisting of two individual collation chains arranged mutually parallel with spacing. In saddle stitchers equipped with a double collation chain of this type, the printed product is bound in the region of a free space between the two chains. Conveyor members in the form of dogs are arranged on the double collation chain and transport the signatures or printed products, straddling the saddle-shaped support, through the binder.
Solutions are further known in which merely a single collation chain, carrying the conveyor members, is used instead of a double collation chain, and along with a support part arranged substantially parallel thereto forms the saddle-shaped support. Finally, solutions are also known in which the saddle-shaped support is formed by two support parts arranged mutually parallel, whilst the printed products are transported on the saddle-shaped support by conveyor members arranged outside the saddle-shaped support. Irrespective of the construction of the saddle-shaped support, the signatures or printed products should be transported and delivered to the respective means for further processing as gently as possible, and a range of devices and methods have previously been developed for this purpose.
EP 1072546 A1 describes a device in which a saddle-shaped support having a ridge is depressed in the delivery region thereof. The printed products are slid onto a fixed blade, which is arranged in this region in a gap between the support parts of the saddle-shaped support and substantially flush with a ridge line extended into the delivery region, and from which said printed products are delivered by gripper members to a means for further processing.
US 2005/0225023 A1 relates to a device for transporting bound printed products consisting of signatures. The device comprises a saddle-shaped support, which is provided with a ridge and on which the printed products are transported by dogs, and a chain, which is provided with active members in the form of blades and introduces them, passing through upwards from below, into a gap in the saddle-shaped support in a delivery region. In this case, the printed products are lifted over a ridge line extended into the delivery region, and thus lifted from the saddle-shaped support and positioned for passing on to a rotating arm. The printed products are lifted to make them easier to grip. This leads to the problem that the gripper members have to receive the printed products precisely in the gap between two blades, in such a way that no undesirable marks are left on the printed products. The device is therefore complex to control, since for this purpose the conveyor members transporting the printed products on the saddle-shaped support, the chain carrying the blades, and the gripper members have to be very precisely synchronised.
WO 2008/008301 A2 describes an adjustable gripper arrangement
In an embodiment, the present invention provides a device for delivering a printed product from a saddle-shaped support. The saddle-shaped support includes a ridge and conveying members and is configured to introduce the printed product, by the conveying members, in a conveying direction to a delivery region of the saddle-shaped support with the printed product straddling the ridge. At least one gripper member is configured to remove the printed product from the saddle-shaped support in the delivery region. The device includes at least two discs that are configured to pass through a gap that extends in the conveying direction and that is disposed, at least in the delivery region, between two support parts of the saddle-shaped support. The at least two discs are rotatable about respective fixed rotation axles that are mutually spaced from one another in the conveying direction. Each of the discs is configured to project intermittently, during the rotation about the respective fixed rotation axles, above a ridge line of the ridge in the delivery region of the saddle-shaped support so as to continuously lift the printed product from the saddle-shaped support in the delivery region.
The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:
In the figures, like reference numerals denote structurally or functionally equivalent components.
An aspect of the invention is to provide a cost-effective device and a corresponding method for delivering printed products gently from a saddle-shaped support.
In an embodiment, the present invention provides a device and a method for delivering printed products from a saddle-shaped support, which comprises a ridge and on which the printed products are initially introduced, straddling the saddle, to a delivery region of the saddle-shaped support in a conveying direction by conveyor members, and finally removed from the delivery region by at least one gripper member, two support parts of the saddle-shaped support being arranged with mutual spacing so as to form between them a gap extending in the conveying direction, at least in the delivery region.
The device according to an embodiment of the invention comprises at least two discs, which are formed so as to be able to pass through the gap in the delivery region, are rotatable about respective fixed rotation axles mutually spaced in the conveying direction, and are formed so as to be able to project intermittently above a ridge line, extended into the delivery region, of the saddle-shaped support, so as to continuously lift the printed products from the delivery region of the saddle-shaped support while rotating about the rotation axles.
In a first embodiment of the device, the discs are formed substantially the same size, and configured in such a way that an uppermost circumferential point of each disc can project the same distance above the ridge line, extended into the delivery region, of the saddle-shaped support.
In a further embodiment of the device, the distance between the rotation axles and a respective uppermost circumferential point of the discs is angle-dependent, the discs each being formed substantially spiral-shaped at least in a circumferential region.
The device according to an embodiment of the invention is used in particular in a saddle stitcher.
In the method according to an embodiment of the invention, the printed products in the delivery region are each continuously lifted from the saddle-shaped support towards the at least one gripper member by at least two rotating discs, which pass through the gap and have respective fixed rotation axles mutually spaced in the conveying direction.
The device and the method make it possible to lift the printed products gently from the saddle-shaped support and thus to prepare them for corresponding removal.
Moreover, with the device according to an embodiment of the invention some parts can be omitted. Referring to US 2005/0225023 A1, the second chain and the associated members such as the blades are no longer necessary, for example. This reduces the manufacturing and maintenance costs of the device and in particular of the saddle stitcher as a whole.
As an alternative to a double collation chain of this type, merely a single collation chain accommodating the conveyor members 9 may be used, and together with a support part arranged substantially parallel thereto forms the saddle-shaped support 4 and the gap 8. The saddle-shaped support 4 may also be formed by two support parts arranged mutually parallel, whilst the printed products are transported on the saddle-shaped support 4 by conveyor members 9 arranged outside the saddle-shaped support 4. In this case the gap 8 is formed between the support parts.
In
The printed products 3 are transported on the saddle-shaped support 4 by the conveyor members 9 fixed to the collation chains in the conveying direction 10, at a speed corresponding to the speed 9c of the conveyor members 9 or of the collation chains. In
The ridge 7 which guides the printed products 3 ends directly upstream from the delivery region 11, a ridge line 7a which extends at the height of the ridge 7 being extensible into the delivery region 11. The device 1 located in the delivery region 11 comprises two discs 14a, 14b, arranged in and passing through the gap 8 between the support parts 4a and 4b and rotating about respective fixed rotation axles 13a, 13b arranged mutually spaced in the conveying direction 10. The discs 14a, 14b are formed so as to be able to project intermittently above the ridge line 7a, extended into the delivery region 11, of the saddle-shaped support 4, so as to continuously lift the printed products 3 from the saddle-shaped support 4 while rotating about the rotation axles 13a, 13b. In addition, the discs 14a, 14b are arranged in succession in the conveying direction 10, in such a way that a first disc 14a arranged downstream is followed by a second disc 14b arranged upstream, said discs being located in a region of the gap 8 of the saddle-shaped support 4 which is concealed by the printed product 3 in the drawing of
An actuator 15 is provided for driving the discs 14a, 14b in rotation about the rotation axles 13a, 13b thereof. Drive trains or shaft trains of the discs 14a, 14b are indicated by connecting lines between the respective rotation axles 13a, 13b and the actuator 15. Embodiments of drives of this type are known and are not explained in greater detail herein. The actuator 15 preferably drives the discs 14a, 14b at the same constant angular velocity 14c. In another embodiment, of the device 1, each disc 14a, 14b is connected to a separate actuator, the discs 14a, 14b preferably being driven at a substantially equal constant angular velocity 14c. “Constant angular velocity” is taken herein to mean an angular velocity 14c which is constant over time when the device 1 is operating as intended. Alternatively, the discs 14a, 14b may also be driven by a drive of a stitching machine of the saddle stitcher.
In addition, a control system 16 is provided for adjusting the angular velocity 14c of the discs 14a, 14b, and the operation thereof is explained in greater detail in relation to
In the following,
In particular in
The discs 14a, 14b are arranged with a fixed distance a2 between the rotation axles 13a and 13b thereof. Large-format printed products are thus transported far enough on the saddle-shaped support 4 that the discs 14a, 14b engage approximately centrally in order to lift them. If a printed product 3 having a fold 2 deviating from a parallel to the ridge line 7a of the saddle-shaped support 4 is to be passed on to the means 6 for further processing, this is carried out by an adjustment, by the control system 16, of the relative angular position of the discs 14a, 14b.
The discs 14a, 14b may also be driven in such a way that the angular position thereof can be adjusted relative to the conveyor members 9. In this way, with the discs 14a, 14b, printed products of different thickness and printed products of variable format can be lifted by the saddle-shaped support 4 in immediate succession, and thus provided to be taken up by the gripper fingers 18a of the gripper member 18. The device 1 is therefore also adapted for further processing of printed products 3 which are produced by digital printing machines and which may have thicknesses and/or formats which differ from printed product to printed product.
As an alternative to arranging the discs 14a, 14b at a fixed distance a2, this distance may also be formed so as to be adjustable. In this case, the minimum distance a2 should be selected in such a way that the discs 14a, 14b do not impede one another in rotation. The ability to adjust the distance a2 between the rotation axles 13a, 13b of the discs 14a, 14b has the advantage of providing increased flexibility as regards the maximum supported format of the printed products 3, specifically a height 21 of the printed products 3. The minimum height 21 is thus predetermined in a fixed manner by the minimum distance a2 between the rotation axles 13a, 13b. By contrast, the maximum height 21 of the printed products 3 can be varied by displacing the rotation axles 13a, 13b in opposite directions, i.e. by displacing the first rotation axle 13a in the conveying direction 10 and the second rotation axle 13b counter to the conveying direction 10.
Further, the discs 14a, 14b are preferably arranged so as to be exchangeable. In particular, they can be exchanged for discs of a different size and shape.
In an initial position, the discs 14a, 14b are orientated, i.e. calibrated, in such a way that after a printed product 3 is introduced into the delivery region 11, respective uppermost circumferential points 19b of the discs 14a, 14b, located on the largest radius of the discs 14a, 14b, project past the extended ridge line 7a of the saddle-shaped support 4 at least intermittently by the same distance a3 at the same moment, in such a way that the printed product is lifted from the support parts 4a, 4b (
The discs 14a, 14b can for example be aligned relative to one another by hand. In particular, if an individual actuator 15 is used for each disc 14a, 14b, they can also be aligned automatically, in that the angular velocity 14c of each disc 14a, 14b is varied until a tab 22 of each disc 14a, 14b, formed by the transition from the largest to the smallest radius of the disc 14a, 14b, has passed through a corresponding control point at the same moment. The control points may for example be established using laser beams, which are interrupted simultaneously and for the same duration, by the tabs 22 of the respective discs 14a, 14b entering the laser beam, if the discs 14a, 14b are running synchronously. The angular velocities 14c of the discs 14a, 14b may change in such a way that the control system 16 actuates the respective actuator 15, to correct the angular speed 14c of the associated disc 14a, 14b, based on an evaluation of the data received by way of the interruption of the laser beams. This calibration method may also be used for intermediate calibration when the conveyor members 9 or the collation chains are running empty. Other known calibration methods may also be used.
During the transition from the situation shown in
To prevent damage to the printed product 3 or undesirable marks on the printed product 3 during lifting, a path velocity of the first uppermost circumferential point 19a, defined by the first contact of at least one of the discs 14a, 14b with the printed product 3 arriving in the delivery region 11, is selected in such a way that the size of a first path velocity component 19d, parallel to the conveying direction 10 of the conveyor members 9 and of the printed products 3 transported thereby, is substantially equal to the speed 9c of the conveyor members 9 of the collation chains. However, depending on the specific operating conditions, the speed 9c of the conveyor members 9 may also differ considerably from the path velocity component 19d.
The first, uppermost circumferential point 19a is shown in
As stated previously, the angular velocity 14c of the discs 14a, 14b can be adjusted via the control system 16. In this way, in accordance with the stated dependencies, the path velocity component 19d can be synchronised with the speed 9c of the conveyor members 9 indirectly using the control system 16. This may be done in such a way that the control system 16 connected to the actuator 15 initially determines the current angular velocity 14c of the discs 14a, 14b. From this, the path velocity component 19d to be expected at the first, uppermost circumferential point 19a can be determined. The control system 16 may also be connected to a drive of the conveyor members 9, i.e. of the collation chains, so as to determine the current speed 9c of the conveyor members 9, which is required for the synchronisation. The angular velocities 14c of the discs 14a, 14b and/or the speed 9c of the conveyor members 9, i.e. of the collation chains, can be determined while the device 1 is in operation. Alternatively, the angular velocity 14c and/or the speed 9c may also be programmed in. Comparing the path velocity component 19d determined in this manner at the first, uppermost circumferential point 19a with the speed 9c of the conveyor members or of the collation chains demonstrates whether the angular velocity 14c of the discs 14a, 14b has to be changed so as to provide equalisation, as required and within particular tolerances, of the two speeds 9c and 19d. The equalisation may take place in a manner analogous to that described for orientating the discs 14a, 14b relative to one another.
When the frequency of the printed products 3 arriving in the delivery region 11 varies, the position of the second circumferential point 19b, located on the largest radius of the discs 14a, 14b, can be adapted accordingly based on the angular velocity 14c of the discs 14a, 14b, preferably while the device 1 is in operation. It may be the case that the angular velocity 14c when the printed product 3 is lifted by the discs 14a, 14b has to be low so as to correspond to the speed 9c of the conveyor members 9; however, in this case the discs 14a, 14b would not have time to rotate sufficiently to reach the correct position for receiving the next printed product 3. In this case, the discs 14a, 14b may be briefly accelerated and braked again cyclically to lift the printed product 3.
The path velocity of the second circumferential point 19b, defined by the moment when the printed product 3 is removed, of the discs 14a, 14b is shown with a path velocity component 19e, and is selected in such a way that the size of the path velocity component 19e parallel to the conveying direction 10 of the conveyor members 9 substantially corresponds to a velocity component 18d, extending in the conveying direction 10 of the conveyor members 9, of the gripper member 18 rotating at an angular velocity. To provide optimally gentle lifting of the printed product 3 from the saddle-shaped support 4 and removal of the printed product 3 from the conveyor member 9, the speed 9c of the respective conveyor member 9 and thus the speed of the printed product 3 is adapted to the velocity component 18d, extending in the conveying direction 10 at the moment of the lifting, of the gripper member 18, in such a way that the velocity component 18d of the gripper member 18 is greater than the speed of the printed product 3. This can be achieved by selecting adapted dimensions of the discs 14a, 14b. From the moment of the first contact of the printed product 3 at the first circumferential point 19a, the printed product 3 is no longer transported by the conveyor members 9, but by the discs 14a, 14b of the device 1. In this context, the printed product 3 follows a forward movement in the conveying direction 10, and simultaneously, as a result of the increasing radius of the discs 14a, 14b, a rising movement away from the saddle-shaped support 4. In addition, the printed product 3 undergoes acceleration. A final speed 3c of the printed product 3 at the moment of removal by the gripper member 18 is determined by the radius of the discs 14a, 14b at the second circumferential point 19b. To adapt the final speed 3c of the printed product 3 to the velocity component 18d of the gripper member 18, the increase in radius of the discs 14a, 14b from the first circumferential point 19a to the second circumferential point 19b may advantageously be selected in such a way that for a constant angular velocity 14c of the discs 14a, 14b, the radius associated with the second circumferential point 19b takes on a value such that the final speed 3c of the printed product 3 is substantially equal to the velocity component 18d of the gripper member 18.
Instead of a rotating gripper member 18, a plurality of rotating gripper members or even one or more adapted stationary gripper members may be used for removing the printed products 3.
In a preferred embodiment, the discs 14a, 14b may be braked or halted during the introduction of a printed product 3 to the delivery region 11 of the saddle-shaped support 4, at a moment when they are not impeding the transport of the printed product 3 in the conveying direction 10. The advantage of this option is that instead of being lifted from the saddle-shaped support 4 and introduced to the means 6 for further processing, one or more printed products 3 may initially be guided onwards on the saddle-shaped support 4 in the conveying direction 10, and may be introduced to another application. This may for example be particularly advantageous if individual printed products 3 are to be delivered to quality control as samples. Further, for example, two different batches of printed products 3, which are to be transported to the saddle-shaped support 4 in succession by the conveyor members 9 but require different further processing, can be processed without changing the devices involved, and thus with minimal interruption. One example of this option is a tandem drive, in which two saddle stitchers are arranged in succession. In this case, the printed products travel unimpeded from the saddle-shaped support of the first saddle stitcher to the saddle-shaped support of the second saddle stitcher, where additional printed products are added. Only at the end of the second saddle stitcher are all of the printed products bound together by a stitching machine. By contrast, the printed products of the first saddle stitcher may already be bound in advance in an operation with active delivery, and only subsequently be introduced to the second saddle stitcher.
Although advantageous embodiments of the invention are shown and described, the invention is not limited thereto, but can be configured and used in other ways within the scope of the appended claims.
Number | Date | Country | Kind |
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0575/11 | Mar 2011 | CH | national |
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1198784 | Aug 1965 | DE |
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Number | Date | Country | |
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20120248676 A1 | Oct 2012 | US |