GB2554339A

GB2554339A - Stapling apparatus and method of operation

Info

Publication number: GB2554339A
Application number: GB1609400.5A
Authority: GB
Inventors: Watkiss Michael
Original assignee: Watkiss Automation Ltd
Current assignee: Watkiss Automation Ltd
Priority date: 2016-05-27
Filing date: 2016-05-27
Publication date: 2018-04-04
Also published as: GB201609400D0

Abstract

A staple head 14 has a controlled drive motor 18 which drives a staple, through a stack of paper for example, and an associated clincher unit 16 bends the staple into the required shape, after which the drive is stopped, and then restarted to form a follow up staple from a wire strip. Preferably, a clincher unit 16 trigger point 50 causes the motor to stop to delay the formation of the follow up staple for a period of time 44 and the clincher is moved by at least 2mm by the time drive is restarted. Multiple staple heads and clincher units may be used in a pamphlet or booklet production apparatus, the drive of each staple head is stopped when its clinch trigger point is reached and the drive of all staple heads is resumed simultaneously; the clincher units may be mounted on individual or a common slide 22. A computer programme containing instructions to execute the steps of the method is also claimed.

Description

(54) Title of the Invention: Stapling apparatus and method of operation

Abstract Title: A method of controlling a staple head by stopping and restarting the motor (57) A staple head 14 has a controlled drive motor 18 which drives a staple, through a stack of paper for example, and an associated clincher unit 16 bends the staple into the required shape, after which the drive is stopped, and then restarted to form a follow up staple from a wire strip. Preferably, a clincher unit 16 trigger point 50 causes the motor to stop to delay the formation of the follow up staple for a period of time 44 and the clincher is moved by at least 2mm by the time drive is restarted. Multiple staple heads and clincher units may be used in a pamphlet or booklet production apparatus, the drive of each staple head is stopped when its clinch trigger point is reached and the drive of all staple heads is resumed simultaneously; the clincher units may be mounted on individual or a common slide 22. A computer programme containing instructions to execute the steps of the method is also claimed.

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At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Stapling Apparatus and Method of Operation

The present invention relates to the operation of staple heads used in particular for stapling or stitching together a stack or sheaf of sheet material particularly for the production of books and booklets, and to related method of operation and booklet forming system employing such staple heads.

The requirement to secure together a stack of sheet material arises in a wide variety of machines and in particular those involved in book/booklet making in which it is commonly required to secure together a sheaf of paper by way of stapling or stitching procedure as part of a booklet/book forming process. Various book making systems are known that employ staple heads or wire-fed stitches for such purposes.

Staple heads find use in lighter duty, and lower cost, book making systems and various examples of stapling heads suitable for use in finishing machines for producing books/booklets are available from Isaberg Rapid AB. These devices comprise electromechanic assemblies arranged to receive a cartridge containing a ribbon of pre-cut wire strips, often in the order of 5000 per cartridge. The cartridge is also provided with two moving elements arranged to be driven by the staple head. The moving elements comprise a staple driver arranged to drive a staple formed from the pre-cut wire strips through the stack of sheet material, and also a staple shaper, arranged to form one of the wire strips into a standard staple shape prior to being driven by the staple driver.

Once the staple has fully penetrated the stack of sheets, a clincher Is then operated to fold both of the protruding legs of the staple and so as to close a staple against the opposite side of the stack of sheets from which penetration occurred.

The staple head includes a motor for driving the mechanical elements of the cartridge so as to achieve the drlving/shaping requirements, and a variety of sensors arranged to trigger the clincher at the appropriate time and indicate when the moveable elements of the head are in a “home” position.

Such known staple heads can operate either by way of a stationary clincher unit and a moveable staple head which can move to and away from the stack of sheets so as to clamp the same against the clincher unit prior to driving the staple through the sheets.

As an alternative, the staple head can be mounted in a relatively stationery manner, and the clincher unit arranged to move into and out of engagement with the stack of sheets as part of the stapling operation.

In order to improve overall efficiency and through input of such known book making systems, multi-head stapling arrangements can be provided in which the stapling of stacks of sheets of printed material can be achieved by the use of two or more stapling heads, and a corresponding number of clinchers.

In one preferred arrangement, removable clinchers are employed and mounted on a common clincher slider so as to move towards, and away from, the stationery staple heads. Of course, in such arrangement, the staple heads are provided beneath the stack of sheets, and the clincher units are moveable in a vertical manner above the stack of sheets.

It is further known that when operating the staple driver and staple shaper of the stapling head it is important that the staple shaper be effective to completely form the staple shape from a pre-cut wire strip so as to allow for subsequent penetration of that staple into the stack of sheets when required, if a wire strip is not formed into a full staple shape then the required stapling function will not occur and, further, damage will also ensue to the operative parts of the staple head.

To ensure such full formation of a staple from a wire strip, there is a characteristic of overdriving of the staple driver such that the driver extends by about 2mm beyond the face of the staple head so as to allow for the full stroke of movement of the staple shaper required so as to fully form the next staple to be deployed from the ribbon of pre-cut wire strips. Such an overdriving procedure is referred to, in particular by Isaberg Rapid AB as “air bending” and it is important there is a suitable gap between the staple head and the clincher at the time such air bending is required so as to allow for the 2mm protrusion of the staple driver and thus the full stroke of the staple shaper.

One example of a known structure of a staple head illustrating the requirement for air bending such as that known from US5794833.

in view of the above mentioned requirement to allow for overdriving of the staple driver by the order of 2mm, it will be appreciated that a gap of at least 2mm must be provided between the staple head and clincher.

In order not to iimit/disadvantageously effect/com promise the efficient stapling operation occurring within such known book making systems the 2mm movement of either the staple head or clincher unit so as to provide for such “air bending” as currently to be achieved in a relatively short time frame.

From the operational characteristics of known staple heads and with regard to a stapling system employing a moveable clincher, it is generally required to move the clincher or retract the clincher by the 2mm distance within a time period in the order of 43ms.

However, since, in view of the relatively large forces to be applied by the clincher unit during the clinching of the staple, it is necessary to employ a relatively fine pitch lead screw in association with the staple motor for moving the clincher unit towards/away from the staple head. Given such requirement for a fine pitch lead screw, and the need to achieve the 2mm of movement within a time period of 43ms, current systems are required to employ a very fast stepper motor or servo motor in order to meet these timely constraints.

However, the provision of such a fast stepper motor or servo motor can prove particularly disadvantageous to the overall operation or configuration/characteristics of a stapling system and can lead to undesired cost and complication and potential operational and maintenance problems.

The present invention seeks to provide for a method of the system for controlling a plurality of staple heads, particularly for use within a book making system, and having advantages over known such methods and systems.

The present invention also seeks to provide for a book/bookiet making system having advantages over known such systems due, in particular, to its improved mode of control of a plurality of staple heads provided for operation therein.

According to one aspect of the present invention there is provided a method of controlling a plurality of staple heads operating in conjunction with a respective plurality of commonly mounted clincher units, comprising the steps of driving a first staple head by way of a drive motor to effect within the first staple head a first staple action on an initial staple and to form a follow up staple from a wire strip; driving a second staple head by way of a drive motor to effect within the second staple head a first staple action, after the first staple action in the first staple head, on an initial staple and to form a follow up staple from a wire strip; moving the position of the clincher units after the staple actions to allow for full formation of the follow-up staples; characterised by the steps of stopping the drive of the first staple head after Its staple action, and restarting the drive of the first staple head for forming the said follow-up staple within the first staple head.

The time constraints on completion of the movement of the clincher unit post clinching operation advantageously do not arise.

Preferably, the step of stopping the drive of the first staple head can comprise the step of stopping the drive motor, and the method can include moving the position of the clincher units by at least 2mm by the time of restarting the drive of the first staple head.

Yet further, the method can include the steps of stopping the drive of the second staple head after its staple action, and restarting the drive of the second staple head for forming the said follow-up staple within the second staple head.

Advantageously, the method can include the step of restarting the drive of the second staple head at the same time as restarting drive of the first staple head.

As one example, the method can include stopping the drive of the staple head at a clinch trigger point.

According to another aspect of the invention there is provided a method of stapling/stitching a sheaf of papers including controlling a plurality of staple heads according to a method as outlined above.

Yet further, the invention can provide for a method of finishing a pamphlet/booklet including a method of stitching/stapling a sheaf of papers as noted above.

According to yet another aspect of the present invention, there is provided a stapling control system arranged for controlling a plurality of staple heads for operating in conjunction with a respective plurality of commonly mounted clincher units, and comprising means for controlling the driving of a first staple head by way of a drive motor to effect within the first staple head a first staple action on an initial staple and to form a follow up staple from a wire strip; means for controlling the driving a second staple head by way of a drive motor to effect within the second staple head a first staple action on an initial staple and to form a follow up staple from a wire strip; means for controlling movement of the position of the clincher units after the staple actions to allow for full formation of the follow-up staples; characterised by means arranged to stop the drive of the first staple head after its staple action, and to restart the drive the first staple head for forming the said follow-up staple within the first staple head.

Of course, it should be appreciated that the system of the present invention can be arranged to operate according to any one or more of the details of the methods noted above.

The invention can also provide for a stapling/stitching apparatus including a plurality of staple heads arranged to operate in conjunction with a respective plurality of commonly mounted clincher units for stapling/stitching a sheaf of paper and including a system as outlined above.

Also, the invention can provide for a finishing apparatus for pamphlet/booklet production including stapling/stitching apparatus as outlined above.

Still further, the invention can provide for a computer program product containing instructions which, when loaded onto a processing device, execute the method steps as outlined above, and to a computer readable medium having recorded thereon such a computer program product.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which:

Fig. 1A is a schematic side elevational view of a stapling station comprising a stapler head and moveable clinch unit such as known in the current art;

Figs. 1B and 1C comprise enlarged part views of the throat gap between the stapler head and clinch unit depending on the thickness of the stack of papers to be stapled;

Fig. 2 is a timing diagram of a multi-head moveable clincher stapler unit according to the current art; and

Fig. 3 is a timing diagram according to the control of a multi-head moveable clincher stapling arrangement according to an embodiment of the present invention.

Turning first to Fig. 1, there is illustrated in schematic form a stapling station 10 for stapling sheets of paper 12A so as to form, for example a booklet or a book within a booklet/book forming system and comprising a staple head 14 located beneath the paper 12A and a moveable clinch unit 16 located above the paper 12A, As will therefore be appreciated, during operation, the staples are driven upwardly from the staple head 14 through the stack of papers 12A so as to protrude upwardly from the upper surface thereof. The protruding legs of the staple are then bent by activation of the clincher 16 so as to be folded back onto the upper surface (as illustrated in Fig. 1 A) of the stack of sheets.

Known apparatus such as that in Fig. 1A can be employed with a wide variety of stacks of paper of different thickness as illustrated by reference to the stack of paper 12B in Fig. 1B and the thicker stack of paper 12G in Fig. 1C.

A sensor within the staple head 14 determines when a staple has completely penetrated the stack of paper 12A, 12B, 12C and the senor then produces a “clinch signal” initiating operation of the clincher so as to bend the staple legs as noted above.

In order to improve the efficiency of systems employing such stapling arrangements, multi-head arrangements are provided in which a plurality of staple heads 14 are provided along with a corresponding plurality of clinch units 16.

The clinch units 16 are commonly mounted byway of a clinch slide so as to be moved towards, and away from, the stack of papers to be stapled as required.

As illustrated with reference to Fig. 1A, a downward force in the order of F 140N per clincher unit is required to be exerted by the clincher unit 16 on the stack of papers 12A, 12B, 12C during the clinching operation. This force arises insofar as the clincher units have to be urged towards the staple heads on a common slider. With a commonly-mounted dual head system the required total force will then be in the order of 280N and, of course, if more than two clincher units on a common slider are employed then the downward force required would be even greater. Likewise, if each clincher is moved by way of its own slider, then the force required can be less and all options are within the scope of the present application.

In order to achieve such force, movement of the plurality of clinch units on the common clinch slide is commonly by way of a fine pitched lead screw.

However, part of the operational sequence of a known multi-head moveable clinch unit stapler requires retraction of the clinch unit by a distance of at least 2mm within 43ms which dictates at a very fast stepper motor, or servo motor should be employed to rotate the lead screw.

Retraction of the clinch unit by at least this 2mm distance is required so that the staple head can overdrive to a sufficient degree such that the staple shaper within the staple head can fully form a staple from one of the wire blanks.

Reference is now made to Fig. 2 so as to illustrate the timing control sequence of a known multi-head moveable clinch stapling unit.

Turning therefore to Fig. 2, there is illustrated in relation to a first, 18 and second 20 stapler and a clinch slide 22 to which a pair of clinch units (not shown) are mounted and operative signals relating thereto and arising during a staple, clinch and air bend cycle during time period t.

Turning first to stapler 18 its motor is driven during period 24 so as to drive an initial staple through a stack of sheets until such time as for penetration from the sheets occurs. Such full penetration is determined by way of a sensor which outputs a clinch signal 30 serving to activate the clincher unit (not shown) associated with the stapler 18 so as to fully form the staple on the upper surface of the stack of sheets. The time period of clinch signal 30 for achieving the clinch operation is in the order of 10ms.

As will be appreciated, advantageously efficient operation is achieved through the use of high speed operative units and, for relatively fast stapling procedures, it will be in the order of 74ms as indicated by arrows X within the clincher unit (not shown) associated with stapler 18 will have to attract the desired 2mm distance so as to allow for full completion of the air bending procedure, and thus full formation of a follow-up staple within the stapler 18 at location 32. Thus, from the commencing of the procedure in stapler 18 up until reference point 32, the motor of the stapler 18 has been driven continuously initially to penetrate the stack of paper with a staple, allow for a clinching operation and then continue to drive the staple driver of the stapler 18 in the above mentioned “overdriven manner so as to extend from the stapler by the in the order of 2mm at point 32 in the timing diagram. Thus, at position 32 when such 2mm overdriving has been achieved, the staple former within the stapler 18 has completed its full stroke so as to fully bend a follow-up wire blank into a full staple shape.

As part of the operating sequence however for such a known multi-head apparatus, a second stapler 20 is also driven by way of its drive motor during a period 26 during which full penetration of a stapler into a stack of sheets is achieved up until clinch signal 34 at which would a clinch unit (not shown) associated with stapler 20 is activated so as to complete the clincher operation to fully bend the upstanding legs of the staple as required.

However, insofar as both clinching (not shown) are mounted in relation to a common clinch slide 22 it will be appreciated that the clinch slide 22 cannot convince its movement so as to retract the clinching associated with staple 18 for the 2mm distance required for air-bending until such time as the clinch operation represented by clinch signal 34 in relation to the second stapler 20 has been completed.

In having to wait for completion of the clinch operation 34 in relation to the second stapler 20, the common clinch slide 22 the time period as indicated by arrows Y to achieve its retraction of at least 2mm. The time period Y is generally in the order of 43ms. However, accounting for the period for the clinch operation to complete as illustrated at 34 in the order of 10ms, this can lead in the order of 33ms for the clinch slide (not shown) to move the distance of 2mm.

The clinch slide 22 is commonly associated with a stepper motor and lead screw. In view of the forces to be exerted by way of the clinch unit and such as discussed in relation to Fig. 1A, the lead screw generally comprises a very fine pitch lead screw. Accordingly, in order to achieve the required 2mm movement within 33ms or even 43ms.

The requirement for such a fast operating stepper motor and lead screw can pose disadvantageous and compromising to element restraints on the bookmaking system and the present invention seeks to overcome such disadvantages.

Turning now to Fig. 3, there is provided a timing diagram illustrating one embodiment of the present invention.

Again, and for comparison purposes, an example is illustrated comprising a dual head stapling unit employing moveable clinchers mounted to a common clinch slide.

Turning therefore to Fig. 3 there is again shown two staplers 18, 20 and a clinch slide 22 provided for the common mounting of two clinch units (not shown in Fig. 3).

Again, and having regard to time period t operational characteristics of the staplers 18, 20 and the clinch slider 22 are illustrated.

Turning first to the timing periods illustrated in relation to stapler 18, there is provided a first bit 42 during which the drive motor 18 that the stapler is on and so as to drive a staple into a stack of sheets of paper so as to fully penetrate through the sheets which then results in a clinch signal 50 as the end of period 48. At completion of the clinch signal 50 serving to control clinching of the staple previously driven through the stack of sheets during the period 42, the motor is then switched off such that there Is no further drive for the stapler 18 during the period 44. The stapler 18 is then effectively dormant during this period.

Turning now to the timings associated with the stapler 20, here, during an initial period 52 with the drive motor on, a staple is driven from the stapler 20 through the stack of paper sheets and then, at 60 to the end of period 58, a clinch signal is generated through sensing the full penetration of the staple from the stapler 20 through the stack of sheets of paper and so as to complete the clinching operation of that staple. The completion of that clinching operation also serves to switch the motor driving the stapler 20 off as illustrated at period 54.

Thus, during the overlapping portions of periods 44 and 54, it will be appreciated that both of the staplers 18, 20 are effectively dormant and there is no operative drive provided by the respective motors.

Since both motors are switched off at this time there is no immediate time pressure on the clinch slide 22 to achieve retraction of the clinch units (not shown in Fig. 3) mounted to the clinch slide 22.

Thus, the 43, or indeed 33ms time constraint arising in the prior art does not arise in relation to the present invention and the protraction by 2mm illustrated at 66 to the attracted position 64 can be achieved without requiring the same high-speed components as found in the prior art and that, once the retracted position 64 has been reached, air bending by way of both of the staplers 18 and 20 can be achieved so as to fully form the next staple to be inserted into a stack of sheets of paper during the next stapling cycle.

As a further advantageous feature, while the actual stapling time is to some degree extended, a final homing sequence of both these staplers 18, 20 and their related clinchers occurs during the “dead” time and so there is no overall detriment to the operational characteristics and efficiencies of a stapler unit operating in accordance with a control sequence embodying the present invention.

it will of course be appreciated that the present invention also provides for a system arranged to provide for a control such as illustrated in relation to Fig. 3 and to various forms of sheet stapling/stitching machines employing such staple head systems and control methods.

The present invention can also be controlled by way of computer program product instructions reflecting the control method steps of the present invention.

Also, it should be appreciated that the invention is not limited to the details of the illustrated embodiment and can be provided in relation to any form of multi-head stapling unit In which post-clinching movement of either the staple head, or clinch, is required for air bending purposes or otherwise. For example, the system and method can employ any configuration of paired staple head and clincher unit, whether staple head above clincher, vice versa or even in laterally spaced side-by-side configuration.

Claims

1. A method of controlling a staple head operating in conjunction with a clincher unit, comprising the steps of driving the said staple head by way of a drive motor to effect within the said staple head a first staple action on an initial staple and to form a follow up staple from a wire strip, and moving the position of the clincher unit after the said staple action to allow for full formation of the follow-up staple; characterised by the steps of stopping the drive of the said staple head after its staple action, and restarting the drive of the said staple head for forming the said follow-up staple within the said staple head.

2. A method as claimed in Claim 1 wherein the step of stopping the drive of the said staple head comprises the step of stopping the drive motor.

3. A method as claimed in Claim 1 or 2, including moving the position of the clincher unit by at least 2mm by the time of restarting the drive of the said staple head.

4. A method as claimed in Claim 1,2 or 3, and including stopping the drive of the staple head at a clinch trigger point.

5. A method as claimed in Claim 1, 2, 3 or 4 and including controlling a plurality of staple heads operating in conjunction with a respective plurality of commonly mounted clincher units, comprising the steps of driving the staple head by way of a drive motor to effect within the staple head a first staple action on an initial staple and to form a follow up staple from a wire strip; driving a second staple head by way of a drive motor to effect within the second staple head a first staple action, after the first staple action in the said staple head, on an initial staple and to form a follow up staple from a wire strip; moving the position of the clincher units after the staple actions to allow for full formation of the follow-up staples; characterised by the steps of stopping the drive of the said staple head after its staple action, and restarting the drive of the said staple head for forming the said follow-up staple within the said staple head

6. A method as claimed in Claim 5, and including the steps of stopping the drive of the second staple head after its staple action, and restarting the drive of the second staple head for forming the said follow-up staple within the second staple head,

7. A method as claimed in Claim 5 or 6, wherein the step of stopping the drive of the second staple head comprises the step of stopping the drive motor.

8. A method as claimed in Claim 5, 6 or 7, including the step of restarting the drive of the second staple head at the same time as restarting drive of the said staple head,

9. A method as claimed in any one or more Claims 5 to 8, and including stopping the drive of the second staple head at a clinch trigger point.

10. A method as claimed in any one or more of Claims 5 to 9, and for operating dual staple heads in conjunction with dual clinches provided on a common clinch slide.

11. A method as claimed in any one or more of Claims 5 to 9, and for operating dual staple heads in conjunction with dual clinches provided on respective separate clinch slide

12. A method of stapling/stitching a sheaf of paper including controlling a plurality of staple heads according to a method as claimed in any one or more the preceding claims.

13. A method of finishing a pamphlet/booklet including a method of stitching/stapling a sheaf of papers as claimed in Claim 12.

14. A stapling control system arranged for controlling a staple head for operating in conjunction with a clincher unit, and comprising means for controlling the driving of the said staple head by way of a drive motor to effect within the said staple head a first staple action on an initial staple and to form a follow up staple from a wire strip; means for controlling movement of the position of the clincher unit after the said staple action to allow for full formation of the followup staple; characterised by means arranged to stop the drive of the said staple head after its staple action, and to restart the drive the said staple head for forming the said follow-up staple within the said staple head.

15. A system as claimed in Claim 11, wherein the said means for stopping the drive of the said staple head comprises means for stopping the drive motor.

16. A system as claimed in Claim 11 or 12, wherein the means for moving the position of the clincher unit is arranged to move it by at least 2mm by the time of restarting the drive of the said staple head.

17. A system as claimed in Claim 14, 15 or 16, and arranged to stop the drive of the staple head at a clinch trigger point.

18. A system as claimed in Claim 14, 15, 16 or 17, and arranged for controlling a plurality of staple heads for operating in conjunction with a respective plurality of clincher units, and comprising means for controlling the driving of the said staple head by way of a drive motor to effect within the said staple head a first staple action on an initial staple and to form a follow up staple from a wire strip; means for controlling the driving a second staple head by way of a drive motor to effect within the second staple head a first staple action on an initial staple and to form a follow up staple from a wire strip; means for controlling movement of the position of the clincher units after the staple actions to allow for full formation of the follow-up staples; characterised by means arranged to stop the drive of the said staple head after its staple action, and to restart the drive the said staple head for forming the said follow-up staple within the said staple head.

19. A system as claimed in Claim 18, and including means arranged to stop the drive of the second staple head after its staple action, and restarting the drive the second staple head for forming the said follow-up staple within the second staple head.

20. A system as claimed in Claim 18 or 19, wherein the said means of stopping the drive of the second staple head comprises means for stopping the drive motor.

21. A system as claimed in Claim 18, 19 or 20, and arranged to restart the drive of the second staple head at the same time as restarting drive of the first staple head.

22. A system as claimed in any one or more of Claims 18 to 21, and arranged to stop the drive of the second staple head at a clinch trigger point.

23. A system as claimed in any one or more of Claims 18 to 22, and arranged for operating dual staple heads in conjunction with dual clinches provided on a common clinch slide.

24. A system as claimed in any one or more of Claims 18 to 22, and arranged for operating dual staple heads in conjunction with dual clincher units provided on separate respective clinch slides.

25. A stapling/stitching apparatus including at least one staple head arranged to operate in conjunction with at least one respective clincher unit for stapling/stitching a stack of sheets and including a system as claimed in any one or more of Claims 14 to 25.

26. A finishing apparatus for pamphlet/booklet production including apparatus as claimed in Claim 25.

27. A computer program product containing instructions which, when loaded onto a processing device, execute the method steps of any one or more of Claims 1 to 13.

28. A computer program product as claimed in Claim 27 and as recorded on a computer readable medium.

29. A computer readable medium having recorded thereon a computer program product as claimed in Claim 28,

30. A method of controlling a staple head operating in conjunction with a clincher unit, and substantially as hereinbefore described with reference to the accompanying drawings,

31. A stapling control system arranged for controlling a staple head for operating in conjunction with a clincher unit and substantially as hereinbefore described with reference to the accompanying drawings.

Intellectual

Property

Office

Application No: Claims searched:

GB 1609400.5 1-30