EP0351489B1 - Stapling-head for wire-stitching machine - Google Patents

Abstract

A stapling-head (10) for a wire-stitching machine, in particular for stitching paperboard parts by means of wire staples, with a head frame (11) with a staple guide (48), which is longitudinally displaceably guided in a bed (17) on the head frame (11), for shaping and holding a staple before it is driven into material to be stitched, with a staple driver (53), which is longitudinally displaceably guided in the staple guide (48) parallel to the direction of movement of the staple guide (48), for expelling the staple from the staple guide (48) and for driving the staple into the material to be stitched, with a cutting device (45) for making stitching-wire portions of predetermined length and a bending device (50) for shaping the staple, and with a drive means. The arrangement is made here in such a way that at least the staple guide (48) and the staple driver (53) can be uncoupled from the drive means, that the bed can be separated from the head frame, and that the bed (17) and the head frame (11) in each case have holding means (18, 21, 29, 40, 27), which correspond to one another and are detachable from one another, for precise positioning of the bed on the head frame (4). <IMAGE>

Description

The invention relates to a stitching head for a wire stitching machine, with the features of the preamble of claim 1.

Such a stitching head is known from DE-OS 36 40 529. In order to be able to wrap staples with changed staple dimensions, i.e. leg length and back width as well as the wire thickness in cardboard with this arrangement, the stapling head must be dismantled to a large extent to replace the separating device, the bending device, as well as the staple guide and the staple driver. This is quite time consuming. The resulting long machine downtimes make the production of small batches uneconomical.

Since the guideways of the clamp guide and the clamp driver are made of hardened steel, these parts are at risk of damage during removal and installation. The high operating speed and the heavy load on the moving parts require relatively tight tolerances to prevent hitting or fluttering and thus increased wear of the components. This affects However, disadvantageous to the assembly times, since with such low-play matching parts, special care must be taken to avoid damage.

The object of the present invention is therefore to create a stitching head for a wire stitching machine which can be easily and quickly adapted to different clip dimensions.

This object is achieved by the stitching head with the features of claim 1.

With this stitching head, the assemblies which are difficult to assemble are held or received on the bed which is connected to the head frame, so that the entire tool set essentially consisting of the bed, the clip guide and the clip driver as a complete quick-change unit in can be removed or installed in the shortest possible time. The arrangement according to the invention enables different preassembled quick-change units to be kept ready, which can be exchanged very quickly when changing from one item of booklet quality to another, even by unskilled assistants.

Maintenance work is also simplified in this way, since the quick-change unit to be serviced can be replaced with an identical one in just a few simple steps, so that longer-lasting maintenance work can be carried out on individual components of the dismantled tool set while the machine has been idle for only a short time.

In a preferred embodiment of the invention, the arrangement is such that the holding means have form-fitting stop means and clamping means. The form-fitting stop means are formed by a groove and at least one corresponding piece. This is a very easy to manufacture arrangement that ensures high accuracy during assembly.

If the stapling head follows the staple a short distance in its conveying direction for a jerk-free movement in order to drive in the clamp, a stable mounting of the head frame is also necessary in the conveying direction of the staple. This stable mounting is advantageously achieved in that the groove has undercut flanks which at least partially encompass the shaped piece.

In a preferred embodiment of the invention, the holding means are a dovetail groove and the shaped piece is a corresponding dovetail guided and held in it. A dovetail guide allows high repeatability during assembly and allows the quick-change unit to have a low overall height. In addition, a dovetail guide is self-adjusting and largely insensitive to canting.

In order to be able to change the tool set quickly and safely even in confined spaces, the arrangement according to the invention is such that the dovetail groove has a first and a second wedge bar, one of which is detachably and movably arranged. This ensures that the quick-change unit can be removed from its dovetail groove by simply disengaging the detachable and movable wedge strip without coming into collision with the other machine parts above or below the stitching head.

So that the bed assumes a precisely predetermined lateral position with respect to the head frame, it is advantageous if the dovetail groove and the shaped piece are aligned essentially parallel to the clamp guide.

In a preferred embodiment of the invention, the arrangement is such that the transverse dimension of the dovetail is essentially constant over its longitudinal extent.

In order to make the arrangement as stable and simple as possible, in a preferred embodiment the molded piece is integrally formed on the bed.

So that the total weight of the moving parts does not become too high or to save material, the dovetail is advantageously divided into several sections in the longitudinal direction. This measure reduces the mass of the parts to be moved without impairing the stability of the arrangement.

In addition, the wedge bar, which is movably and displaceably held on the head frame, is formed by a clamping claw which can be clamped to the bed with a cylinder screw against the dovetail. This ensures easy handling since the bed is slidable into the desired position along the dovetail groove and can be securely fixed there.

In order to prevent the bed from sliding along the dovetail groove from the head frame when the clamping claw is loosened, the arrangement is advantageously made such that an indexing device between the head frame and the bed for determining the position of the bed on the head frame transversely to the longitudinal direction of the Holding means is arranged.

In a preferred embodiment, this indexing device is formed by a feather key arranged transversely to the longitudinal direction of the dovetail groove.

To further improve handling, the bed is designed to hold a wire feed, the cutting device and the bending device. This means that all the assemblies influencing the bracket geometry are combined in one quick-change unit and can therefore be exchanged together.

In order to achieve the most compact possible structure, in a preferred embodiment the arrangement is such that the cutting device is integrally formed on the side of the clamp guide.

In addition, in one embodiment of the invention, the staple guide with the staple driver is held captive in the bed. This ensures that these difficult to assemble components of the stitching head are not during operation or detach from each other by incorrectly or unintentionally putting down the quick-change unit.

Fig. 1

den erfindungsgemäßen Heftkopf in einer perspektivischen Explosionsdarstellung,

Fig. 2

eine von dem Kopfrahmen des Heftkopfes nach Fig. 1 abnehmbare Schnellwechseleinheit in einer schematischen Seitenansicht,

Fig. 3

die Schnellwechseleinheit nach Fig. 2 in einer schematischen Vorderansicht,

Fig. 4

einen Heftkopf nach Fig. 1 in einer anderen Ausführungsform in einer schematischen Querschnittsdarstellung,

Fig. 5

eine lösbare Verbindung zwischen der Antriebsvorrichtung und dem Klammertreiber bzw. der Klammerführung in einer schematischen Seitenansicht, und

Fig. 6

die lösbare Verbindung zwischen der Antriebsvorrichtung und dem Klammertreiber bzw. der Klammerführung nach Fig. 5 in einer schematischen Schnittdarstellung längs der Linien VI -- VI in der Fig. 5.

In the drawing, an embodiment of the invention is shown. Show it:

Fig. 1

the stitching head according to the invention in a perspective exploded view,

Fig. 2

2 shows a quick-change unit which can be removed from the head frame of the stitching head according to FIG. 1 in a schematic side view,

Fig. 3

2 in a schematic front view,

Fig. 4

1 in another embodiment in a schematic cross-sectional representation,

Fig. 5

a detachable connection between the drive device and the staple driver or the staple guide in a schematic side view, and

Fig. 6

5 in a schematic sectional view along the lines VI - VI in FIG. 5. The detachable connection between the drive device and the clamp driver or the clamp guide according to FIG.

A part of a stitching head 10 is illustrated in a highly schematic manner in FIG. 1. Only those parts are shown which are necessary to explain the invention. The other components, which per se belong to a stitching head, are taken on their own, known and omitted for the sake of clarity.

The stitching head 10 has a head frame 11 with a substantially elongated shape as die-cast aluminum, at the upper end of which a plain bearing bush 12 for pivotably mounting the stitching head 10 extends across the head frame. In order to be able to carry out a controlled pendulum movement with the stitching head 10 about the axis of the slide bearing bush 12, the head frame 11 has on its one long side in the lower third a second slide bearing bush 14, which is oriented parallel to the slide bearing bush 12 and by means of a flange 15 to the front protrudes from the head frame. The pivoting movement is brought about by a drive device, which is not described in further detail, and takes place about a horizontal axis.

To accommodate a bed 17, the head frame 11 has a flat ground rectangular receiving surface 18, to which a wedge strip 20 extends laterally on the same side of the head frame 11 on which the slide bearing bush 14 is arranged, over the entire length of the receiving surface 18. The wedge strip 20 has a bevel 21 on its narrow longitudinal side facing the receiving surface 18, so that an acute angle is formed together with the receiving surface 18 (see FIG. 4).

In the central area of the receiving surface 18, a key 24 oriented transversely to the longitudinal extent of the wedge strip 20 is let into the receiving surface 18 and serves as an indexing device for determining the position of the bed 17 on the head frame 11 in the longitudinal direction.

A clamping claw 25 is arranged on the head frame 11 by means of a prismatic spacer 26 and an Allen screw 27 on the longitudinal side 22 of the head frame 11 opposite the wedge strip 20 and jumping backwards relative to the receiving surface 18. The clamping claw 25 has a substantially T-shaped shape, with its crossbeam 28 being ground flat in the region of the side surface 19 facing the receiving surface 18. The longitudinal side of the head frame 11 is also chamfered with respect to the receiving surface, so that the side surface 19 of the clamping claw 25 includes an angle with the receiving surface 18 which corresponds to the angle of the chamfer 21 with the receiving surface 18. The arrangement is otherwise such that by means of the spacer 26 or the correspondingly angled head frame 11 in this area the clamping claw 25 with its side facing the receiving surface 18 encloses an angle which corresponds to the aforementioned angle of the chamfer 21 on the wedge bar. Thus, the chamfer 21, the receiving surface 18 and the side surface 19 of the clamping claw 25 form a dovetail groove 29, which is oriented vertically, that is to say transversely to the axis of the slide bearing bush 12. The clamping claw 25 has an elongated hole 31 in the region of its central beam 26, with which it is screwed onto the head frame 11 by the screw 27. Through the elongated hole 31, it is possible only by slightly loosening the Screw 27 to shift the clamping claw 25 obliquely to the rear, so that the dovetail groove 29 is open on one long side.

The bed 17 consists of two parallel spaced guide jaws 33 and 34, the facing surfaces 35 and 36 of which are ground. The two jaws 33 and 34 are connected to one another by means of three cross legs 38 to form a U-profile. The three cross legs 38 are all of equal length, chamfered at their ends and project laterally beyond the two jaws 33 and 34, so that a dovetail 40 corresponding to the dovetail groove 29 results.

The middle of the three cross legs 38 has on its side facing the receiving surface 18 a recess 42 into which the feather key 24 can be inserted with little play.

One jaw 34 is widened laterally in its lower region and is set up to receive the wire feed 43. The wire feeder 43 is otherwise known and is therefore not described in further detail. In order to understand the function of the stitching head 10, it is only necessary to explain that the wire feed 43 laterally brings the wire into the interior of the U-profile formed by the two jaws 33 and 34 and the transverse legs 38, where the wire is described by one described below Cutting device 45 is assembled into correspondingly long pieces of wire.

A clip guide 48 has an elongated shape and has an approximately U-shaped profile in cross section, the outer dimensions of which correspond to the inside dimensions of the bed 17, so that the clip guide 48 is guided in the bed 17 so as to be longitudinally displaceable with little play. In the lower area of the side of the clamp guide 48 facing away from the bed 17, an insert 50 is provided, by means of which the clear width of the U-profile narrows; the width corresponds to the back width of the clip. In this insert 50, which acts together with the wire holder claw 65 as a bending device, the hardened lower end of a staple driver 53 is guided in a longitudinally displaceable manner. At the upper end of the clamp driver 53 an articulated head 55 is flanged to the side, in which a needle bearing bush 56 is fitted, the axis of rotation of which extends transversely to the longitudinal direction of the clamp guide 48.

The articulated head 55 serves, as described further below, to connect the clamp driver 48 to the drive device.

The clamp driver 53, which is guided in a longitudinally displaceable manner in the clamp guide 48, has a rectangular cross section and an elongated shape. The lower hardened end of the clamp driver 53 is dimensioned depending on the width of the cross leg of the clamp and is held interchangeably in the factory at the upper part of the clamp driver 53. At the upper end of the clamp ejector 53, a joint head 58 is also flanged, in which a needle bearing bush 59 is fitted. The joint head 58 is, similar to the joint head 55, set offset laterally upwards from the clamp driver 53, the arrangement being such that the two rod ends 55 and 58 are mounted opposite one another on one of the two long sides and do not interfere with the up and down movement of the clamp guide 48 or the clamp driver 53.

In order to keep the clamp guide 48 and the clamp driver 53 in the bed 17 captive, a cover plate 63 is screwed to the two jaws 34 and 35 by means of several screws 61, so that the clamp guide 48 in the bed 17 and the clamp driver 53 in the clamp guide 48 are arranged vertically movable and the whole arrangement can be removed as a quick-change unit from the head frame 11 or flanged to it.

On the cover plate 63, a wire holder claw 65 is articulated, which is pivoted parallel to the longitudinal extension of the clamp driver 53 about an axis 66 in the central region of the cover plate 63 and through a recess 67 open on the lower edge of the cover plate 63, projecting towards it lower end of the clamp driver 53 is pivotable.

The free end of the wire holder claw 65 is provided with a head 68 which has on its inside a transverse groove 71 which runs transversely to the longitudinal direction of the clamp driver 53 and into which the wire feed 43 feeds the wire required for the formation of the clamp. By means of an S-shaped spring 67 which is screwed to the cover plate 63 at its upper end and which bears on the head 68 of the wire holder claw 65 with its lower end, the latter is pressed in the direction of the clamp driver 53 (see also FIG. 2). .

FIG. 3 illustrates a quick-change unit in which a wire 70 is brought laterally through the wire feed 43 in the area of the clip guide 48 or the clip driver 53. For a better illustration, the cover plate 63 is omitted so that the cutting device 45 is visible laterally on the clamp guide 48. This is a sharp-edged nose 72 formed on the side of the clamp guide 48, which is guided along the edge of the wire feed 43 during the downward movement of the clamp guide 48 and thus cuts off a piece corresponding to the clamp dimensions from the wire. Since the wire piece is held by the claw 68 during this process, the wire piece is simultaneously bent into the clamp. Finally, it lies curved in the channel of the clamp guide 48.

As indicated schematically, two connecting plates 76 are arranged on each of the two joint heads 55 and 58, which establish the connection to a drive device (not shown). The releasable connection between the two rod ends 55 and 58 and the drive device is described below.

Fig. 4 illustrates in detail the cross-sectional shape of the stitching head 10 shown in Fig. 1 only in an overview. It should be noted that the bed 17, in Fig. 1 composed of several parts in Fig. 4 is designed as a one-piece aluminum die-cast part. For reasons of weight saving, the clamp guide 48 also has a double T-shaped cross-sectional profile, the clamp driver 53 being received in a recess 49 pointing away from the bed 17.

As can be clearly seen in FIG. 4, the head frame 11 has an angled flange 77 for receiving the screw 27, to which the spacer 26 also connects in a rectangular recess 78. On its side facing the clamping claw 25, the spacer 26 has a projecting transverse edge 80, so that when the screw 27 is screwed on, the clamping claw 25 rests only on this transverse edge 80 on the spacer 26 and thus without tilting with the dovetail 40 and the bed 17 can come into engagement.

5 and 6 illustrate how, by means of the two connecting plates 76, the clamp guide 48 is connected to a swivel arm 80 of the drive device, which is not further illustrated. Analogously to the joint head 55 of the clamp guide 48, the swivel arm 80 likewise has a needle bearing bush 82 through which a cylindrical bolt 83 projects axially. A snap ring 84 is seated in a recessed groove 8 at its front end. The connecting plates 76 have an elongated shape and have at both ends two bores 86 and 87 of the same diameter, which are dimensioned such that the cylinder bolt 83 is straight through the hole 87 the connecting plates 76 fits through. The two connecting plates 76 are held captively on the swivel arm 80 on both sides by the head 85 or the snap ring 84. The needle bearing bush 56 of the joint head 55 receives a bearing pin 88, at one end of which a thread 89 is formed, which protrudes through one of the connecting plates 76. The thread 89 has a smaller diameter than the pin 88, so that a shoulder 91 is formed in the transition from the bearing pin 81 to the thread 89, on which the connecting plate is screwed by means of a nut 92, lies firmly. On its other end face, the pin 88 is provided with a stepped bore 93, which has an internal thread 94. A cylinder screw 96 can be screwed into this internal thread 94 through the hole 86 of the connecting plate 76.

An analogous arrangement is provided for connecting the joint head 58 of the clamp driver 53 to the drive device. This connection is therefore not described further.

To remove the quick-change unit from the head frame 11, the screw 27 of the clamping claw 25 is loosened and the quick-change unit is pivoted slightly around the joint heads 55 and 58, respectively. As soon as the dovetail 14 has come free from the wedge bar 20 or from the clamping claw 25, the two screws 96 are unscrewed from the bearing pin 88 and the connecting plate 76 thus loosened is pivoted up. It is now possible to remove the quick-change unit laterally, the bearing pin 88 sliding out of the needle bearing bushes 56 and 58, respectively. The assembly is done in reverse order.

Claims (18)

1. Stapling head for a wire stapling machine, particularly for stapling cardboard sections by means of wire staples, comprising a head frame (11),
      a longitudinally guided stapling guide (48) in a bed (17) on the head frame (11), to form and hold a staple before driving it into the goods to be stapled,
      a staple driver (53) longitudinally guided in the stapling guide (48) parallel to the direction of movement of the stapling guide (48), for driving the staple into the goods to be stapled,
      cutting means (45) for manufacturing wire staple sections of predetermined length, and bending means (50) to form the staple, and having two drive arms to synchronise the different machine movements of the stapling guide and staple driver, and
      characterised by,

   - having a quick-release joint (96) disposed between the drive arms and staple driver (53), and that the bed (17) is separated from the head frame (11) and is constructed from independent components, whereby the bed (17) and the head frame (11) correspond respectively to each other, as well as having means of holding (18, 21, 29, 40, 27) separable from each other, for a precise positioning of the bed (17) on to the head frame (11).
2. Stapling head as Claim 1, characterised by the means of holding (18, 21, 29, 40, 27) having positive abutment means (18, 21, 29, 40) and clamping means.
3. Stapling head as Claim 2, characterised by the positive abutment means (18, 21, 29, 40) , being formed by means of a groove (18, 21, 29) and at least one fitting (40) corresponding to it.
4. Stapling head as Claim 3, characterised by the groove (18, 21, 29) having undercut flanks (21, 29), which engage the fitting (40) at least partially.
5. Stapling head as Claim 2, characterised by the holding means being a swallowtail groove (18, 21, 29), and the fitting corresponding to it, is guided into the swallowtail (40) and held.
6. Stapling head as Claim 5, characterised by the swallowtail groove (18, 21, 29) having an initial (21) and a second tapered gib (29), of which one (29) is detachable and moveable.
7. Stapling head as Claim 5, characterised by the swallowtail groove (18, 21, 29) and the fitting (40) being aligned essentially parallel to the stapling guide (48).
8. Stapling head as Claim 5, characterised by the cross section dimensions of the swallowtail (40) being kept substantially constant over its entire length.
9. Stapling head as Claim 3, characterised by the fitting (40) on the bed (17) being constructed in one piece.
10. Stapling head as Claim 5, characterised by the swallowtail (40) being subdivided longitudinally into several sections.
11. Stapling head as Claim 6, characterised by the tapered gib (28) held moveable and adjustable in the head frame (11), being formed by means of a cylindrical screw (27) against the swallowtail (40), with a flexible clamping shoe (25) on the bed (17).
12. Stapling head as Claim 2, characterised by index means (24) being disposed between the head frame (11) and the bed (17), to fix the position of the bed (17) on the head frame (11) transversely to the longitudinal direction of the means of holding (18, 21, 29, 40, 27).
13. Stapling head as Claim 12, characterised by the index device being formed by an adjusting screw (24) disposed transversely to the longitudinal direction of the swallowtail groove (40).
14. Stapling head as Claim 2, characterised by the bed (17) being disposed for incorporating a wire guide (43).
15. Stapling head as Claim 2, characterised by the bed (17) being disposed for incorporating the cutting device (45).
16. Stapling head as Claim 1, characterised by the cutting device (45) being integrally mounted in one piece laterally on the stapling guide (48)
17. Stapling head as Claim 2, characterised by the bed (17) being disposed for incorporating the bending device (50).
18. Stapling head as Claim 2, characterised by the stapling guide (48) being held securely with the staple drive (53) in the bed (17).

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