EP1195265B1 - Means for feeding, positioning and cutting a wire in a sheet stitcher for staple forming - Google Patents

Abstract

The staple wire (W) advance motor (80) is controlled by the action of two L-shaped levers (11,12) pivoted and coupled in such a way that their ends are separated, according to the thickness of a stack of sheets to be stapled together, to form a cut length of the correct size.

Description

The invention relates to a device for feeding, centering and cutting a stitching wire in a sheet stacking stapler for subsequent forming a staple, wherein the supply of the stitching wire from a stitching wire supply by means of a feed unit on the one hand in lengths, the length of a predetermined stack thickness of a stapling sheet stack and signal from a sensor for detecting the leading end of the supplied stitching wire, and on the other hand guided to a position to staple forming means of the stapler, in which the supplied stapling wire length portion locked by a clamping unit and cut by a wire cutting unit is symmetrical or centric to the center of the staple forming means is positioned.

There are devices for feeding, centering and cutting a stitching wire in a sheet stacking stapler for the purpose of forming a staple of the type mentioned, which are used in duplicating machines.

DE 197 12876-A1 discloses a sheet stacking stapler in which individual stitching wire sections are cut from an input stitching wire of stitching wire stock, centered to a former and driver, formed into a staple and driven into a sheet stack, and one depending is mounted displaceably from the stapling to hefty thickness of a stack of sheets stapling wire cutting device. At the cutting device engages a pivotally mounted control lever, which is in engagement with a cam unit. The cam unit is driven by a one-way clutch, one end of which is connected to the cam unit and driven by a stepper motor of a stitching wire feeding unit. The other end of the one-way clutch is available with a Transport wheel for stitching wire transport in engagement. The cam unit has cam sections associated with different sheet stack thicknesses.

In accordance with the measured sheet stack thickness, the stepper motor rotates the cam unit to a position which places the cutter over the control lever in a position to cut off the length of the wire section associated with the sheet stack thickness.

A disadvantage of this disclosed sheet stacking stapler that on the one hand feeding the stitching wire to the determined for the sheet stack thickness length section and centering of the stitching wire section additionally by means of control sections of the stepper motor driven and switchable by means of clutch control cams using an additional stitching wire backstop must be performed and, on the other hand, the positioning of the cutting device must additionally be carried out by means of stepper motor-controlled control cams, which is complicated in terms of design and cost and critical in terms of functional reliability and positioning accuracy. In addition, in the event of a malfunction after stapling wire feed, in which the stapling wire has to be determined in its length because of a subsequently changed sheet stack height, the stapling wire supplied can only be transported back by canceling the backstop and by operating the stepping motor in the opposite direction.

The invention is therefore an object of the invention to provide a device of the type mentioned, which does not have these disadvantages, but which ensures a fast, accurate and easy operation of a sheet stacking stapler, even in case of failure in an automated environment, and also has a simple inexpensive structure.

The object is achieved with a device according to claim 1 according to the invention in that for centering the stitching wire length section two levers are arranged in the region of the staple forming means, with their first free ends loosely coupled to each other in operative connection and are in each case about an associated bearing point by feeding the stitching wire and abutment of the leading end at the second free end of the first of the lever counter-clockwise, synchronously and by an equal amount symmetrically to the staple forming means against a spring force of a spring element are pivotable ; and that at the second free end of the second lever, the Drahtabschneideinheit is arranged such that it is movable by means of the second lever along the leading end of the stitching wire back and forth.

Advantageously, the two levers are substantially L-shaped, the bearing point is arranged in each case in the region of an intersection of their L-legs; their first mutually facing L-leg first free ends of the lever with coupling means, by means of which the levers are in operative connection with each other; and whose second L-legs extending substantially parallel to each other have second free ends of the levers.

In addition, the second lever relative to the first lever on shorter first and second leg lengths, on the one hand to lead the leading end of the stitching wire on the second end of the second lever over to the second end of the first lever and on the other hand due to the shortened length of the second leg compensate for shorter pivoting of the second end of the second lever.

Furthermore, the second end of the second lever is advantageously designed as a first electrical switching contact of the stitching wire leading end detection sensor, the second electrical switching contact of which is formed by the supplied leading end of the stitching wire, and the stitching wire feeding unit is formed by a microprocessor-controlled stepping motor Driven drive unit, wherein the respective required length of the stitching wire length portion can be determined by a predetermined number of steps of the stepping motor from detecting the stitching wire leading end by the sensor.

Fig. 1

die erfindungsgemäße Vorrichtung an einer teilweise dargestellten Blattstapel-Hefteinrichtung mit Heftdraht-Zuführeinheit, Drahtabschneideinheit und Heftklammer-Formungsmittel in einer räumlichen Darstellung,

Fig. 2

die erfindungsgemäße Vorrichtung nach Fig. 1 in einer vergrößerten teilweise geöffneten Teilansicht,

Fig. 3

die erfindungsgemäße Vorrichtung nach Fig. 1 in einer Frontansicht,

Fig.4

die erfindungsgemäße Vorrichtung nach Fig. 3 mit Hebelsystem in Einzelteildarstellung.

The other features and advantages are described in the description of the embodiments of the invention shown in the drawings and the other dependent claims. The drawing shows in the

Fig. 1

the device according to the invention in a partially illustrated sheet stacking stapling device with stitching wire feed unit, wire cutting unit and staple forming means in a spatial representation,

Fig. 2

1 shows the device according to the invention in an enlarged partially opened partial view,

Fig. 3

the device according to the invention of FIG. 1 in a front view,

Figure 4

the device according to the invention of FIG. 3 with lever system in single part representation.

The following description of Figs. 1 to 4 relates to a preferred embodiment of the device 1 according to the invention for feeding, centering and cutting a stitching wire W in a sheet stacking stapler. The device is in this case arranged in a duplicating device of known type, such as a copier.

The inventive device is part of a commercially available, partially unspecified described and illustrated stapling device for feeding the stitching wire W of a not shown, conventional stitching wire supply and cutting a stitching wire length section WS, as well as for shaping and driving of staples in a batt stack ST.

The sheet stacking stapling device shown in FIGS. 1 to 3 has, on the one hand, a stapling head with the device 1 according to the invention, as well as with a feed unit 2 for the stapling wire W, a wire filament insert 5, a clamping unit 4 for the stapling wire length section WS and staple forming means 3 for the cut stapling wire length section, and on the other hand shows a conventional, schematically represented anvil unit 9 with a bearing surface for the stack of sheets ST to be stapled, the anvil unit 9 also having a conventional bending unit, not shown, driven through the sheet stack Having ends of the staple.

The stitching wire feed unit 2 has, disposed on a chassis 6 of the stapler, a driven by a microprocessor-controlled drive unit 8 transport roller 21 and pinch roller 22 for pinch wire transport, and an inlet tube 23 for guiding the stitching wire W before and an insertion funnel 24, a guide tube 25 and a wire guide sleeve 26 after the rollers 21, 22 on. The feeding of the stitching wire W by means of the feed unit takes place here in length sections WS whose length is determined by a predetermined stack thickness of stapled sheet stack ST and a signal from a sensor 10 for detecting a leading end WE of the supplied stitching wire, wherein the feeding of the stitching wire W in a position is taken to the staple forming means 3 of the stapler in which the stapling wire length WS locked by the clamping unit 4 and cut by the wire cutting unit 5 is positioned centrally of the staple forming means.

The stitching wire feed unit 2 can be driven by means of a microprocessor-controlled stepping motor 80 of the drive unit 8, wherein the respectively required length of the stitching wire length WS can be determined by a predetermined number of steps of the stepping motor 80, starting from the detection of the stitching wire leading end WE by the sensor 10 is.

As shown in particular in FIGS. 1 and 3, the usual clamping unit 4 and staple-forming means 3 are arranged centric to the vertical center axis or symmetry axis A of the stapler and at right angles centered to guided through the straightening sleeve 26 stitching wire length WS on the chassis 6 and guided its upper end by means of the drive unit 8 of the stitching wire feed unit 2 driven in common, on the chassis 6 also arranged first and second Control curves 71, 72 of the cam unit 7 in a known manner for clamping the stitching wire length section WS, for forming the staple and for driving into the sheet stack ST operable.

The device 1 has, as shown in particular in Figures 3 and 4, for centering the stitching wire length section WS two levers 11; 12 in the region laterally of the staple forming means 3, which with their first free ends 11.1; 12.1 are loosely coupled in operative connection with each other and an associated, arranged on the chassis bearing 13, 14 by feeding the stitching wire W and abutment of the leading end WE at the second free end 11.2 of the first lever 11 in opposite directions, synchronously and symmetrically by an equal amount to the staple forming means against a spring force of a spring element 15 are pivotable.

The Drahtabschneideinheit 5, which is carried out in a conventional manner, is disposed on the second free end 12.2 of the second lever 12 of the device 1, such that for cutting the stitching wire length section WS in dependence on the sheet stack thickness, the Drahtabschneideinheit 5 by means of the second lever 12 along the length section WS of the stitching wire W back and forth is movable.

The two levers 11, 12 are substantially L-shaped, whose associated bearing point 13, 14 is arranged in each case in the region of an intersection of its L-legs. Each bearing 13, 14 has a arranged on the chassis 6 of the stapler bearing pin 13, 14, on which the respective lever 11, 12 is pivotally mounted by means of its bearing bore 11.0;

First mutually facing L-legs of the two levers 11, 12 have at their first free ends 11.1, 12.1 coupling means 11.3, 12.3, by means of which the levers are in operative connection with each other. The coupling means in this case have on one of the levers 11 a slot 11.3 extending towards the bearing points and on the other lever 12 a cylindrical guide pin 12.3 protruding through the slot.

Second substantially parallel adjacent L-legs have the second free ends 11.2; 12.2 of the first and second levers 11, 12 on.

The second lever 12 in this case has compared to the first lever 11 shorter first and second leg lengths, on the one hand the lead end WE of the stitching wire W starting from the straightening sleeve on the second end 12.2 of the second lever 12 to the second end 11.2 of the first lever 11 to lead and on the other hand to compensate for a shortened length of the second leg caused by the shorter pivoting or pivoting amount of the second end 12.2 of the second lever 12.

The second end 11. 2 of the first lever 11 is designed as a first electrical switching contact 10. 1 of the stitching wire guide end WE sensor 10 whose second electrical switching contact is formed by means of the supplied leading end WE of the stitching wire W, the stitching wire W via the wire sealing sleeve 26 is connectable or connected to a ground terminal of a power supply unit of the copying machine.

Here, in the region of the second end 11.2 of the first lever 11, a substantially conical recess 10.1 is arranged for guiding and receiving the supplied stapling wire leading end WE, which also serves for defined or precise contact only at its base or in the region of its lowest point electrical contact point 10.1 of the sensor 10 is formed. The second end 11.2 of the first lever 11 is thus made of an electrically non-conductive material except for the sensor pad 10.1. As a connection to a conventional device control unit, not shown, an electrical signal line 10.3 is provided.

The Drahtabschneideinheit 5 is mounted with its guide member 54 in a arranged on the chassis 6 of the sheet stacking stapler linear guide rail 61 of known type horizontally and at right angles to the axis of symmetry A of the stapler slidably mounted; and by means of a cylinder bolt 51 mounted on it and protruding through a slot 12.4 on the second end portion 12.2 of the second lever 12, loosely with the second one Lever 12 coupled and thus operatively connected thereto, wherein the slot extends along a longitudinal extent of the second lever from the end 12.2 in the direction of the bearing 14 (see Fig. 4).

The Drahtabschneideinheit 5 is on the one hand after their displacement in the position predetermined by the sheet stack thickness position, which is effected by feeding the stitching wire to the required length Ws, locked by means of the cam discs 71, 72 controlled conventional ram means 73 of the stapler, and on the other hand is the upper , on the holding block 55 of the Drahtabschneideinheit 5 arranged cutting blade 52 by means of the plunger means 73 in a conventional manner against a lower fixed cutting blade 53 of the holding block vertically movable.

The spring element 15 is, as shown in Figures 1 to 3, designed as a leg spring 15 which is pivotally mounted on the bearing pin 14 of the second lever 12; wherein the first spring leg 15.1 is locked to a chassis part 81 of the stapler or the drive unit 8 and whose second spring leg 15.2 engages the second lever 12 in the region of its second end 12.2 on the cylinder pin 51 of the Drahtabschneideinheit, so by the spring force of the leg spring 15th Both levers 11, 12 are held with their second free ends 11.2, 12.2 against each other in the direction of the axis of symmetry A in an initial position or can be brought into the initial position. 2, the leg spring for the purpose of free pivoting and leadership with their arranged between the first and second spring leg bearing lug on the bearing pin 14 between a resting on the second lever 12 lower guide flange 14.1 and a fixed at the upper end of Lagcrbolzens 14 upper guide flange 14.2 arranged.

The operation of the device is the following:

First, the stitching wire W by means of the driven by the program-controlled stepping motor 80 transport 21 and pinch roller 22 of the feed unit 2 with his Leading WE transported until electrical contact with the wire guide sleeve 26.

After the blue sheet thickness is detected in the usual manner and the sheet stack ST between the stapling head and the anvil 9 of the sheet stacking stapler promoted and stored on a storage surface of the anvil 9, the stitching wire WS by means of the feed unit 2 and the microprocessor-controlled stepper motor 80 until the electrical contact of the leading end WE of the stitching wire with the switching contact 10.1 of the sensor 10 at the second end 11.2 of the located in the initial position or initial position first lever 11 of the device 1 according to the invention transported.

If the sheet stack ST here has a thickness or height for which a staple with the shortest stitching wire length WS is sufficient, the stitching wire feed is stopped by uncoupling the transport roller 21 from the stepping motor 80 and blocking the transport roller 21, this with a usual, not shown Kupptungseinheit done.

At the same time, the cam unit 7 is coupled by means of the coupling unit and thus clamped and cut by operating the clamping unit 4, the Drahtabschneideinheit 5 and the staple forming / -Inreibungsmittel 3 by means of the cam discs 71, 72 and the plunger 73 in the usual way the stitching wire length section WS , and the staple formed and driven with its two pointed end portions through the stack of sheets and bent by bending jaws of the anvil unit 9.

However, if the sheet stack ST has a greater thickness, for which a larger stitching wire length section for forming a staple with longer end portions is required, the stitching wire W by means of the feed unit 2 until reaching the necessary length by the required number of steps from microprocessor-controlled stepping motor 80 further transported or supplied.

In this further feeding of the stitching wire W by the feed unit 2, the two levers 11 and 12 of the device I with their second ends 11.2 and 12.2 by means of the leading end WE of the stitching wire against the spring force of the leg spring 15 from its initial / initial position symmetrically from the axis of symmetry A. The stapler pivots away while the Drahtabschneideinheit 5 against the stitching wire feeding direction pushed to the same extent as the stitching wire feed from the axis of symmetry A.

After the staple has been driven into the sheet stack ST and stapled, on the one hand the clamping unit 5 with its lower / upper jaws 41, 42, the staple forming / driving means with their first / second forming jaws 32, 33 and driver 31, and on the other hand the two levers 11, 12 and the Drahtabschneideinheit 5 by means of the cam unit 7 and drive unit 8 is returned to its original position. Here, the return of the lever 11 takes place; 12 and wire cutting unit 5, guided by the cam discs 71, 72, by means of the spring force effect of the leg spring 15th

Subsequent to the return of the said functional units to their initial position, the cam unit 7 is uncoupled from the drive unit 8, the stitching wire feed unit 2 coupled again to the re-stapling wire feed and the above-described functional sequence, if requested, restarted.

In the case of a faulty or faulty stitching wire feed, if the stapling wire length section WS is too short or too long, the stitching wire W is returned to the stitching wire W by means of the feed unit 2 and the stepping motor 80 of the drive unit 8 until the contact point 10.1 of the sensor 10 is released then transported forward again to contact with the contact point 10.1, wherein a further forward transport of the stitching wire, as described above, is determined by the thickness or height of the sheet stack ST.

reference numeral

A

Symmetry axis of the sheet stacking stapler

ST

sheet stack

W

stitching wire

WE

Leading end of the stapling wire

WS

Length of stapling wire for forming a staple

1.

Device for centering and cutting a stitching wire length section

Second

Feed unit for the stitching wire

Third

Staple forming means

4th

Clamping unit for stitching wire length section

5th

wire-cutting

6th

Chassis of the sheet pile stapler

7th

Cam unit

8th.

Drive unit for stitching wire feed unit and cam unit

9th

Anvil unit of the sheet stack stapler

10th

Sensor for leading end of stitching wire

10.1

first switching contact of the sensor / contact point at the 1st end of the 1st lever

10.2

second switching contact of the sensor / leading end of the stitching wire

10.3

electrical signal line

11th

first L-shaped lever of the device

11.0

Bearing hole on the first lever

11.1

first free end of the first lever

11.2

second free end of the first lever

11.3

Coupling means for lever / slot at the first end of the first lever

11.4

Coupling means for Drahtabschneideinheit / slot at the second end of the lever

12th

second L-shaped lever of the device

12.1

first free end of the second lever

12.2

second free end of the second lever

12.3

Coupling means for lever / guide pin at the first end of the second lever

12.4

Coupling means for Drahtabschneideinheit / slot at the second end of the lever

13th

Bearing point / bearing pin for first lever

14th

Bearing point / bearing pin for second lever

14.1

lower guide flange for second lever

14.2

Upper guide flange for spring element

15th

Spring element / leg spring for lever

15.1

first spring leg of the spring element

15.2

second spring leg of the spring element

21st

Transport roller for stitching wire transport to stitching wire feed unit

22nd

Pinch roller for stitching wire transport to stitching wire feed unit

23rd

Wire input pipe

24th

Wire entry funnel

25th

Wire guide tube

26th

Wire straightening sleeve

27th

Staple collectors

28th

first staple form baking

29th

second staple form baking

30th

lower stitching wire jaw

31st

upper stitching wire jaw

32nd

Cylinder pins on wire cutting unit

33rd

upper cutting blade

34th

lower cutting blade

35th

Guide part of the Drahtabschneideinheit

36th

Holding block for cutting knife

37th

Guide rail for wire cutting unit

38th

first cam

39th

second cam

40th

Ram means on first control cam (for upper cutting blade)

80th

drive motor

81st

Support plate for drive unit

82nd

Locking hole for the first spring leg of the spring element

Claims (10)

1. Device (1) for centering and cutting a stapling wire (W) in a sheet stack stapling device for the purpose of subsequent forming of a staple, the device consisting of a supply unit (2) and a staple forming element (3), the supply of the stapling wire from a wire supply being carried out, on the one hand, in length sections (WS) using a supply unit (2), the lengths of which sections (WS) are determined by a predetermined stack thickness of a sheet stack (ST) to be stapled and by a signal from a sensor (10) for detecting a guide end (WE) of the supplied stapling wire, and the supply of the stapling wire being carried out, on the other hand, to a position relative to staple-forming elements (3) of the stapling device, in which position the stapling wire length section that has been supplied, stopped by means of a clamping unit (4), and cut by a wire-cutting unit (5), is concentric to the center of the staple-forming elements,
   characterized in that
   for centering the stapling wire length section (WS), two levers (11, 12) are mounted in the area of the staple-forming elements (3), which levers (11, 12) are loosely coupled to and in operative connection with each other with their first free ends (11.1, 12.1), and each of which levers (11, 12) can be swiveled around an assigned bearing point (13, 14) against a spring force of a spring element (15) by supplying the stapling wire (W) and impacting its guide end (WE) on the second free end (11.2) of the first lever (11), in opposite directions, synchronously and by the same amount symmetrically to the staple-forming elements and that,
   for cutting the stapling wire length section (WS), the wire-cutting unit (5) is mounted on the second free end (12.2) of the second lever (12) in such a way that the wire-cutting unit (5) can be moved back and forth along the length section of the stapling wire by means of the second lever.
2. Device according to claim 1,
   characterized in that
   the two levers (11,12) are designed so that they are essentially L-shaped, with the respective bearing point (13, 14) arranged in the area of a point of intersection of their L-sides; the first L-sides, which point toward each other, are the first free ends (11.1, 12.1) of the levers with coupling elements (11.3, 12.3) by means of which the levers are in operative connection with each other; and the second L-sides, which run essentially parallel next to each other, are the second free ends (11.; 12.2) of the levers.
3. Device according to claim 2,
   characterized in that
   each bearing point (13, 14) has a bearing pin (13, 14) mounted on the frame (6) of the stapling device, on which bearing pin (13, 14) the respective lever (11, 12) is mounted by means of its bearing hole (11.0, 12.0) so that it can swivel; and the coupling elements have a slot (11.3) on one of the levers (11), the slot (11.3) extending to the bearing points, and the coupling elements have a cylindrical guide pin (12.3) on the other lever (12), the guide pin (12.3) extending through the slot.
4. Device according to claim 1 or 3,
   characterized in that
   the second lever (12) has shorter first and second side lengths in comparison to the first lever (11) in order to be able to guide the guide end (WE) of the stapling wire (W) past the second end (12.2) of the second lever (12) to the second end (11.2) of the first lever (11) and also to compensate for the shorter swivel path of the second end (12.2) of the second lever (12) due to the reduced length of the second side.
5. Device according to claim 1 or 4,
   characterized in that
   the second end (11.2) of the first lever (11) is designed as a first electrical switching contact (10.1) of the sensor (10) for detecting the stapling wire guide end (WE), the second electrical switching contact of which sensor (10) is formed by means of the supplied guide end (WE) of the stapling wire (W).
6. Device according to claim 5,
   characterized in that
   in the area of the second end (11.2) of the first lever (11), an essentially conical recess (10.1) is arranged for guiding and holding the supplied stapling wire guide end (WE), the recess being formed, at its base, at the lowest point, as an electrical contact point (10.1) of the sensor (10).
7. Device according to claim 3,
   characterized in that
   the spring element (15) is designed as a leg spring (15) which is held on the bearing pin (14) of the second lever (12), the first spring leg (15.1) being stopped on a frame part (81) of the stapling device and the second spring leg (15.2) engaging on the second lever in the area of its second end (12.2) in such a way that, due to the spring force of the leg spring (15), both levers (11, 12) are held in an initial position with their second free ends (11.2, 12.2) against each other in the direction of the symmetrical axis (A).
8. Device according to claim 1,4, or 7,
   characterized in that
   the wire-cutting unit (5) is mounted so that it can slide on a linear guide rail (61) mounted on the sheet stack stapling device; and is loosely coupled to and thus in operative connection with the second lever (12) by means of a cylinder pin (51) that is mounted on the guide rail (61) and extends through a slot (12.4) on the second end area (12.2) of the second lever (12), the slot extending along a length extension of the second lever.
9. Device according to claim 8,
   characterized in that
   after it is slid by supply of the stapling wire (W) into the position predetermined by the sheet stack height, the wire-cutting unit (5) can be stopped by means of tappets (73) of a control cam unit (7) of the stapling device, the tappets (73) controlled by cam disks (71, 72), and an upper cutting knife (52) of the wire-cutting unit (5) is movable against a lower fixed cutting knife (53) by means of the tappets (73).
10. Device according to claim 1, 6, or 8,
    characterized in that
    the stapling wire supply unit is drivable by means of a microprocessor-controlled stepper motor (80) of a drive unit (8), the required length of the stapling wire length section (WS) being determined in each case by a predetermined number of steps of the stepper motor, starting from the detection of the stapling wire guide end (WE) by the sensor (10).

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