EP0516625B1 - Cutting device for a wire removing machine - Google Patents

Abstract

A cutting device for a wire removing machine for cutting through tie wires of bales, in particular cellulose bales, has essentially two elongate cutters (5, 6) that can move back and forth in relation to each other, each provided at their cutting edges with a row of regularly spaced teeth (16, 17) having an undercut on their front flanks, in the cutting direction. In order to precisely define the moment when the wires are cut and at the same time ensure that a gripping device has already reliably clamped the tie wires before they are cut through by the cutting device, the front flanks (18, 19) of the teeth (16, 17) have at their lower end, in the area of the tooth root, a receiving pocket (21, 22) for at least one tie wire, the back ends of the receiving pockets (21, 22) forming knife-edges (24). The sections of the front flanks (18, 19) of the teeth (16, 17) that extend between the tip (20) of the tooth and the corresponding receiving pocket (21 or 22) form blunt slide edges.

Description

The invention relates to a cutting device for a de-wiring machine for severing the tying wires of bales, in particular of cellulose bales, with two elongated knives which can be pushed back and forth relative to one another and are provided on their cutting sides with a row of teeth each consisting of teeth arranged one behind the other at regular intervals, which have an undercut on their flanks at the front in the cutting direction.

In a known cutting device of the type mentioned (DE-PS 28 16 912), the front flanks of the teeth of both cutter bars are designed as cutting over their entire height.

Such a cutting device is used, for example, in a wire removal machine, as is known from DE-PS 37 07 966. In such a dewiring machine, the cutting device is combined with a gripping device which, after cutting the wires, brings them into a predetermined position in which they can be reliably gripped by a winding device.

The invention has for its object to develop the known cutting device in that the Cutting time can be precisely defined to ensure that the gripping device already holds the tying wires reliably before they are cut by the cutting device.

According to the invention this object is achieved in that the front flanks of the teeth each have a receiving pocket for at least one lacing wire at their lower ends in the region of the tooth base, that the rear ends of the receiving pockets are designed as a cutting edge and that the front flanks of the teeth are in their section are formed between the tooth head and the receiving pocket as blunt, continuously backward sliding edges.

In the cutting device according to the invention, the tying wires to be severed are drawn from the blunt sliding edges towards the tooth feet into the receiving pockets. The process of severing the tying wires drawn into the receiving pockets only begins when the cutting edges, which are formed at the ends of the receiving pockets located in the cutting direction, have approached one another to such an extent that their distance is less than a wire diameter. The beginning of the cutting process can thus be precisely defined in the cutting device according to the invention and can be matched to the work steps of a gripping device which interacts with the cutting device.

Preferably, the receiving pockets are formed deeper than the diameter of the wire to be cut, so that it can be pulled completely into the respective receiving pocket.

The receiving pockets should be formed deeper than half the diameter of the wire to be cut, so that there are two opposing receiving pockets can completely enclose the respective wire.

The ends of the receiving pockets, which are designed as cutting edges, can be arcuate, preferably semicircular.

The ends of the receiving pockets, which are designed as cutting edges, expediently extend over their entire height, so that a flawless and reliable cut can be made.

The cutting edges can be formed by an undercut.

On the heads of the teeth of both cutter bars, bevels are preferably formed, which extend from the highest point of the respective tooth lying in the extension of the front flanks at an angle to the side of the tooth feet. As a result, a starting position of the knife bars can be set, in which two adjacent teeth of the opposite knives form a roof-shaped unit, at which the wire is rejected and fed to the respective tooth gaps.

The invention is illustrated in the drawing, for example, and described in detail below with reference to the drawing.

Fig. 1

einen Schnitt durch eine Schneidvorrichtung,

Fig. 2

eine Ansicht eines Ausschnitts eines Messers aus Fig. 1 in Richtung der Pfeile II-II,

Fig. 3

einen Schnitt entlang der Linie III-III aus Fig. 2,

Fig. 4

in schematischer Darstellung einen Ausschnitt aus der Seitenansicht der Schneidvorrichtung, bei der die Zähne in der Ausgangsposition zur Aufnahme eines Drahtes stehen,

Fig. 5

den gleichen Ausschnitt wie Fig. 4 mit einer Messerstellung, bei der der Draht bereits ein Stück zwischen die Zähne eingezogen ist,

Fig. 6

den gleichen Ausschnitt wie Fig. 4 mit einer Messerstellung, bei der sich der zu durchtrennende Draht im Inneren einer Aufnahmetasche befindet, und

Fig. 7

den gleichen Ausschnitt mit einer Messerstellung nach dem Durchtrennen des Drahtes.

Show it:

Fig. 1

a section through a cutting device,

Fig. 2

2 shows a view of a section of a knife from FIG. 1 in the direction of arrows II-II,

Fig. 3

3 shows a section along the line III-III from FIG. 2,

Fig. 4

a schematic representation of a detail from the side view of the cutting device, in which the teeth are in the starting position for receiving a wire,

Fig. 5

the same detail as Fig. 4 with a knife position, in which the wire is already pulled a bit between the teeth,

Fig. 6

the same section as Fig. 4 with a knife position, in which the wire to be cut is inside a pocket, and

Fig. 7

the same cutout with a knife position after cutting the wire.

1 of the drawing, the cutting device consists of a cutter bar 1, which is fastened with the aid of screws 2 to a machine frame 3, which is only shown in part.

The cutter bar 1 consists essentially of a holder 4, which has a U-shaped cross section, and two elongated knives 5 and 6, which are guided in a longitudinally displaceable manner between the legs 7 and 8 of the U-shaped holder 4.

To improve the sliding properties between the legs 7 and 8 of the U-shaped bracket and the two knives 5 and 6 bearing metal strips 9 and 10 are provided.

To adjust the play between the two knives 5 and 6, a plurality of screws 11 are arranged distributed over the length of the knife bar 1, which extend through the two legs 7 and 8 of the U-shaped holder 4 and the knives 5 and 6 and at their threaded end 12 are provided with a lock nut 13. By tightening and loosening the nut 13, the play between the two knives 5 and 6 can be adjusted precisely or adjusted when the knife bar 1 is worn or deformed.

In order to ensure the longitudinal displaceability of the two knives 5 and 6 despite the continuous screws 11, the two knives 5 and 6 are provided in the area of the screws 11 with elongated holes 14 and 15, which are at least as long as the intended strokes of the two knives 5 and 6. As drives for the two knives 5 and 6, lifting cylinders (not shown in the drawing) can be provided, for example.

In the embodiment shown in the drawing, both knives 5 and 6 are moved in opposite directions relative to the U-shaped holder over the same distances. But there is also the possibility that one of the two knives is fixed and only the other is driven.

Both knives 5 and 6 have teeth 16 and 17 arranged one behind the other on their cutting sides at uniform intervals, the front flanks 18 and 19 of which, at an angle to one another, move past one another like scissors will.

The front tooth flanks 18 and 19 extend from the tooth head 20 in the respective plane of the knife with a corresponding undercut obliquely to the rear, so that when the knives are actuated the interacting front flanks 18 and 19 of the teeth 16 and 17 initially in the area of the tooth heads 20 touch, while the other areas of the front flanks 18 and 19 come into contact with each other only when the knives 5 and 6 continue to move.

The interacting front flanks 18 and 19 of the teeth 16 and 17 each have at their lower ends in the area of the respective tooth base a receiving pocket 21 and 22, respectively, which extends back a little from the respective front flank 18 and 19. The receiving pockets 21 and 22 are higher than the diameter of a wire 23 to be cut and deeper than half the diameter of the wire.

The rear ends of the receiving pockets 21 and 22 in the cutting direction are designed as cutting edges 24, which are created by applying a relief grinding 25.

In the sections between the respective tooth head 20 and the receiving pocket 21 and 22, the front flanks 18 and 19 of the teeth 16 and 17 are formed as blunt sliding edges. Due to this design feature, the strapping wires can only be severed in the area of the receiving pockets 21 and 22 with the aid of the cutting edges 24, while the blunt flanks 18 and 19 only serve to grip the strapping wires to be severed and in Towards the receiving pockets 21 and 22.

On the tooth heads 20 of the teeth 16 and 17 of both knives 5 and 6, bevels 28 are formed which extend from the highest point of the respective tooth 16 and 17, which is in the extension of the front flanks 18 and 19, at an angle in the direction of the tooth feet extend there.

In Figures 4 to 7, some relative positions of the knives 5 and 6 to each other are shown.

4 shows the initial position of the knives 5 and 6, in which two adjacent teeth 16 and 17 each form a roof-shaped unit 26, the two adjoining bevels 28 of the tooth heads 20 defining the roof pitch. When the cutter bar runs against the bale provided with the tying wires, the respective wires 23, on which such a roof-shaped unit 26 strikes, are rejected to the side, so that each wire is fed to a tooth gap.

If the two knives 5 and 6 are then displaced relative to one another by a tooth pitch, the respective wire 23, as shown in FIG. 5, is enclosed by the two front flanks 18 and 19 of two interacting teeth 16 and 17. Since the flanks 18 and 19 are blunt, the wire 23 cannot be severed in the area of the flanks, but is pulled in the direction of the receiving pockets 21 and 22.

When the wire 23 has reached the area of the receiving pockets 21 and 22, the two immediately opposite receiving pockets 21 and 22 form an all-round closed area, as shown in FIG. 6 27, so that the wire 23 comes to lie exactly between the cutting edges 24.

When the knives 5 and 6 are further displaced relative to one another, the two cutting edges 24 move past one another and cut through the wire 23. Such a position of the two knives 5 and 6 that goes beyond the cutting position is illustrated in FIG. 7. After cutting the wire 23, the two knives 5 and 6 can be moved back to their starting position, which is illustrated in FIG. 4.

Claims (8)

1. A cutting device for a wire removing machine, for cutting through the binding wires of bales, particularly bales of paper pulp, with two elongate cutters adapted for displacement to and fro in respect of each other and provided on their cutting sides with respective rows of teeth consisting of teeth disposed serially at regular intervals and having an undercut on their flanks which are in front in the direction of cutting, characterised in that the front flanks (18, 19) of the teeth (16, 17) have at their bottom ends in the region of the tooth root, respective receiving pockets (21, 22) to accommodate at least one binding wire (23) and in that the rear ends of the receiving pockets (21, 22) are constructed as a cutting edge (24) and in that the portion of the front flanks (18, 19) of the teeth (16, 17) between the tooth head (20) and the respective receiving pocket (21, 22) is constructed as a blunt and steadily rearwardly extending sliding edge.
2. A cutting device according to claim 1, characterised in that the receiving pockets (21, 22) are constructed to be deeper than the diameter of the wire (23) which is to be cut.
3. A cutting device according to claim 1 or 2, characterised in that the receiving pockets (21, 22) are constructed to be deeper than half the diameter of the wire (23) which is to be cut.
4. A cutting device according to one of claims 1 to 3, characterised in that the ends of the receiving pockets (21, 22) which are constructed as cutting edges (23) are arcuately shaped.
5. A cutting device according to claim 4, characterised in that the ends of the receiving pockets (21, 22) which are constructed as cutting edges (24) are substantially semi-circular in shape.
6. A cutting device according to one of claims 1 to 5, characterised in that the ends of the receiving pockets (21, 22) which are constructed as cutting edges (24) extend over their entire height.
7. A cutting device according to one of claims 1 to 6, characterised in that the cutting edges (24) are constituted by a relief (25) formed by grinding.
8. A cutting device according to one of claims 1 to 7, characterised in that constructed on the heads (20) of the teeth (16, 17) of both cutters (5, 6) are sloping surfaces (28) which extend from the highest point of the respective tooth (16,17) which is a prolongation of the front flanks (18, 19) and at an angle to the side of the tooth roots.

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