EP1539415A1

EP1539415A1 - Device located on scrap shears or similar, for reducing the frictional forces that occur as a result of the action of the material to be crushed on the closing motion

Info

Publication number: EP1539415A1
Application number: EP03798052A
Authority: EP
Inventors: Thomas Deimel; Sebastian Schipp; Karsten Rudolf Schneider
Original assignee: Atlas Copco Construction Tools GmbH; Atlas Copco Construction Tools AB
Current assignee: Construction Tools GmbH; Construction Tools PC AB
Priority date: 2002-09-18
Filing date: 2003-08-01
Publication date: 2005-06-15
Also published as: DE10243125A1; JP2005538843A; US20050150343A1; KR20050054869A; WO2004028729A1

Abstract

The invention relates to scrap shears (1) comprising several jaw arms (2a, 2b, 3), which can execute a pivoting motion in relation to one another in a closing or opening direction of the scrap shears. At least one jaw arm is equipped with a counter-bearing element (12) on the end section lying opposite the mounting (4), said element being displaced, (at least temporarily), in relation to the jaw arm carrying said element between a working position and a reduced friction position. The counter-bearing (12) is configured in such a way that the distance between its external surface (12b), which faces away from the carrying jaw arm and the mating surface (3b) of the neighbouring jaw arm (3), which faces towards said external surface, increases with the relative displacement of the counter-bearing element towards the reduced friction position.

Description

Device on scrap shears or the like - to reduce the frictional forces that occur under the action of the crushing material in the course of the closing movement

description

The invention relates to a device on scrap shears or the like - to reduce the frictional forces that occur under the influence of the crushing material in the course of the closing movement - with several jaw arms that can execute a pivoting movement relative to each other in the closing or opening direction of the scrap shears, the of the holder End sections facing away from the scrap shears have at least two mutually adjacent jaw arms, which together form a cutting region that narrows with the pivoting movement in the closing direction, and wherein the end sections of mutually adjacent jaw arms overlap at least in the closed position of the scrap shears.

Scrap shears and comparable shredding devices that are attached to a carrier device - for example a hydraulic excavator - are used to separate or shred objects made of steel or other, in particular metallic materials.

In the simplest case, scrap shears are equipped with two jaw arms which can be pivoted relative to one another, the end sections of which, facing away from the holder of the scrap shears, have cutting elements on the sides facing one another; a cutting gap is formed between them when the respective end sections approach each other.

The invention is the like on all such scrap shears. applicable, regardless of the manner in which and with which drive means the pivoting movement of the jaw arms is brought about relative to one another in the closing or opening direction of the scrap shears. The scrap shear or the like. can thus be designed such that either only one jaw arm or both jaw arms can be pivoted with respect to the holder and that the jaw arms movable with respect to the holder either have their own drive means or are driven together. In addition, the invention is also on scrap shears or the like. applicable with more than two jaw arms, in particular in embodiments with a double jaw having two outer jaw arms and a middle jaw arm, the end section of which can be pivoted between their outer jaw arms by a relative movement between the middle jaw arm and the double jaw. The relative movement between the double jaw and the middle jaw arm can be made possible in that either the double jaw and the middle jaw arm are movable with respect to the holder of the scrap shears. In embodiments with only one jaw arm that is movable relative to the holder, the middle jaw arm can predominantly be pivoted, while the double jaw is a component of the scrap shears that is not movable with respect to the holder.

In order to prevent a further, undesirable evasive movement of the middle jaw arm, a wear-resistant slide plate or a cutting element is arranged on the jaw arm of the double jaw - which lies on the side of the middle jaw arm facing away from the cutting gap - as abutment in the last-mentioned double-jaw types.

During the cutting process, transverse forces are generated in the cutting area of the scrap shears under the influence of the shredding material, which act approximately perpendicular to the plane of the swivel movement and can increase the distance between the jaw arms involved in the cutting area, with the result that the cutting gap also experiences a corresponding change and that Shredding material can be drawn into it. If the transverse forces reach correspondingly high values, frictional forces can act between the adjacent jaw arms, which cannot be overcome by means of the drive forces available for operating the scrap shear. The result of this is that the scrap shears are no longer capable of working and the clamping condition that has occurred - possibly with considerable time and effort - must be eliminated.

The invention is based on the object of making clamping states that occur during the cutting process manageable in that the components of the scrap shears interacting in the cutting area are suitably designed and / or handled.

The novel device should in particular also be designed in such a way that the scrap shears remain functional even when there are unfavorable operating conditions by reducing the static friction forces and the drive forces required for the opening movement.

The object is achieved by a device having the features of claim 1. The basic idea of the invention is to equip at least one jaw arm at its end section facing away from the holder - in other words in the region in which transverse forces can act on adjacent jaw arms during the cutting process under the action of the comminution material - with an abutment element. This can - at least temporarily - move relative to the supporting jaw arm between a working position and a friction reduction position in such a way that its relative movement in the direction of the friction reduction position increases the distance between its outer surface facing away from the supporting jaw arm and the counter surface of the adjacent jaw arm facing it. This is equivalent to the fact that the distance between the correspondingly moved outer surface and a reference surface of the supporting jaw arm which is fixed relative thereto is reduced.

Insofar as the aforementioned requirements are met, the abutment element can be designed and arranged as desired in the context of the invention. In particular, the abutment element itself can also be designed as a cutting element or can be equipped with a cutting element.

Furthermore, according to the teaching of the invention, several abutment elements can be used at the same time, and also in different functions, for example as a cutting element itself or as a sliding plate supporting the adjacent jaw arm. With regard to the underlying task, at least one of the existing abutment elements must be designed in such a way that it can be moved either automatically (ie without external intervention) or by influencing it from the outside, for example in the direction of the friction reduction position. “Working position” is to be understood as the position of the abutment element in question, which it assumes in normal operation of the scrap shear. By moving the abutment element in the direction of the friction reduction position, the frictional forces effective at the relevant end sections are reduced, so that any jamming - for example, by Initiation of the pivoting movement in the opening direction of the scrap shears - by equipping the scrap shears with at least one abutment element - which can be moved in a suitable manner with respect to the load-bearing jaw arm - ensures that those triggered by the transverse forces in the cutting area and possibly also the further one Environmentally influencing frictional forces can be reduced in a suitable manner, so that the scrap shear remains operational without a long downtime.

In principle, the subject matter of the invention can be designed such that the abutment element can adjust itself freely on the supporting jaw arm in accordance with the available freedom of movement. Alternatively, however, an embodiment is also possible in which the abutment element can be locked with respect to the supporting cheek arm by means of at least one locking element (claim 2). This embodiment enables the following handling:

In the normal state, the abutment element is kept immovable with respect to the supporting jaw arm in a predetermined working position via the at least one locking element (for example at least one screw connection). If a clamping should occur in the course of the cutting process, the locking is released so that the abutment element can now move in the direction of the friction reduction position. After removing the clamping, the abutment element can then be locked again after reaching the working position. The embodiment in question is thus designed such that the abutment element is only temporarily movable with respect to the supporting jaw arm.

Depending on the operational circumstances and requirements, the subject matter of the invention can also be developed in such a way that the locking element is designed to be remotely operable (claim 3).

In particular, the locking element can consist of at least one clamping cylinder, which normally blocks the abutment element with respect to the supporting jaw arm and, if necessary, is released by arbitrary actuation from the outside, so that the abutment element is subsequently movable in the manner already mentioned. In the simplest case, the clamping cylinder is designed as a hydraulic cylinder; alternatively, however, other types of locking elements can also be used, in particular motor-driven threaded spindles.

Within the scope of the invention, the abutment element can be designed as a wedge element, which can be moved at least temporarily in the direction of the friction-reducing position on the occasion of the opening movement of the scrap shears relative to the supporting jaw arm (claim 4).

This embodiment naturally presupposes that the supporting jaw arm has a suitable guide surface. In cooperation with the wedge element, this must be such that the movement of the wedge element in the opening direction of the scrap shears results in an increase in the distance between its outer surface and the mating surface of the adjacent jaw arm facing it.

In the simplest case, the wedge element is supported on the supporting jaw arm in such a way that the wedge element moved relative to this at the same time executes a transverse movement parallel to itself (claim 5).

In another embodiment of the subject matter of the invention, the abutment element is designed to be displaceable transversely to the level of the pivoting movement (claim 6). This embodiment can be further developed in that the

Abutment element is designed to be displaceable by means of screw elements on the one hand and lockable on the other (claim 7).

Alternatively, the abutment element can also be designed in the manner of a cylinder unit and can be displaced by means of a pressurized fluid

(Claim 8).

The cylinder unit preferably has a reset, the effect of which from

Fluid-induced holding force is opposite (claim 9).

The provision - in the simplest case a mechanical suspension - can be designed in such a way that it is effective either in the direction of the working position or in the direction of the friction reduction position.

Preferably, the cylinder assembly under the action of the fluid in one

Operating state transferred in which the abutment element assumes its working position (claim 10).

In a further embodiment variant of the subject matter of the invention, the abutment element is designed to be pivotable with respect to the supporting jaw arm in such a way that in the friction-reducing position, the distance between the then obliquely aligned abutment outer surface and the counter surface of the adjacent jaw arm increases - as seen in the closing direction of the scrap shears (claim 11). The pivot position of the abutment element can be changed in a particularly simple manner under the action of either a screw means (claim 12) or an eccentric (claim 13).

It goes without saying that within the framework of the teaching according to the invention - if necessary taking into account the design of the scrap shear or comparable shredding device - several of the design variants mentioned above can also be used simultaneously. This applies in particular to the case in which the scrap shears or comparable shredding device has more than two jaw arms, for example the double jaw mentioned at the beginning and a central jaw arm interacting with it. The invention is explained in more detail below with reference to the drawing; In this example a scrap shear with three jaw arms - namely a double jaw having two outer jaw arms and a pivotable middle jaw arm - is shown as an example. As already mentioned, the invention can also be used on differently designed shredding devices, in particular on scrap shears equipped with only two jaw arms. In detail show:

La is a schematic representation of a view of scrap shears,

1b in a spatial oblique view, the double jaw and the associated middle jaw arm of the scrap shear shown in Fig. La,

2a shows a highly schematic section through the double jaw and the central jaw arm of a scrap shear designed according to the invention in a position assumed during the cutting process,

2b shows a section corresponding to FIG. 2a after initiating the movement of the scrap shears in the opening direction,

3a highly schematic a section through the double jaw and the middle jaw arm of a scrap shear designed according to the invention in a position assumed in the course of the cutting process, both the outer jaw arms of the double jaw and the middle jaw arm being equipped with a wedge element,

3b shows a section corresponding to FIG. 3a after initiating the movement of the scrap shears in the opening direction,

4a is a highly schematic section through the double jaw and the middle jaw arm of a scrap shear designed according to the invention in a position assumed during the cutting process, an outer jaw arm of the double jaw having an abutment element in the manner of a cylinder unit, 4b shows a section corresponding to FIG. 4a after initiating the movement of the scrap shears in the opening direction,

5a is a highly schematic section through the double jaw and the middle jaw arm of a scrap shear designed according to the invention in a position assumed in the course of the cutting process, an outer jaw arm of the double jaw having an abutment element which can be pivoted by means of an eccentric,

5b shows a section corresponding to FIG. 5a after initiating the movement of the scrap shears in the opening direction,

6a is a highly schematic section through the double jaw and the middle jaw arm of a scrap shear designed in accordance with the invention in a position assumed in the course of the cutting process, an outer jaw arm of the double jaw having an abutment element which can be pivoted by means of a screw element, and

6b shows a section corresponding to FIG. 6a after initiating the movement of the scrap shears in the opening direction.

The hydraulic scrap shear 1 shown in FIG. 1 a has a double jaw 2 and a central jaw arm 3 as main components known per se, which are movably attached to a holder 4. This is equipped on the side facing away from the main components 2, 3 with a rotary console 5, via which it can be rotatably attached to a carrier device, not shown - for example a hydraulic excavator.

While the middle jaw arm 3 is designed with one arm, the double jaw 2 comprises two outer jaw arms, namely the first jaw arm 2a located at the front in FIG. 1 a and the second jaw arm 2 b located at a distance behind it and visible in FIG. 1 b.

For actuating the main components 2, 3 there are two hydraulic cylinders 6, 7, which are articulated on the bracket 4 on the one hand via their cylinder housing 6a or 7a below the rotary bracket 5 and on the other hand via their piston rods 6b or 7b with the double jaw 2 or are connected to the middle jaw arm 3. By extending the hydraulic cylinders 6 and 7, the main components 2 and 3 - which in turn are pivotally supported on the holder 4 - are moved such that the scrap shear 1 executes a closing movement in the direction of the arrow 8. The return stroke movement of the hydraulic cylinders 6 and 7 results in an opposite pivoting movement of the main components 2 and 3, so that the scrap shear 1 executes a movement in the opening direction.

While the middle jaw arm 3 has three cutting elements arranged next to one another in its longitudinal direction on its outer side, which is visible, for example, in FIG

9, the first jaw arm 2a is equipped on its end face (see Fig. 1b) with three cutting elements 10 arranged one behind the other in its longitudinal direction, i.e. the cutting elements 9 and 10 are detachably fastened on mutually facing sides of the middle jaw arm 3 and the first jaw arm 2a and together form the cutting area of the scrap shears 1 in the course of the closing movement in the direction of arrow 8. This results from the fact that the middle jaw arm 3 is made shorter is as the outer jaw arms 2a, 2b of the double jaw and is guided such that it at least partially engages with the free end portion 3a in the course of the cutting process in the space between the jaw arms 2a and 2b; accordingly the end sections of mutually adjacent jaw arms overlap - namely on the one hand the end sections of the jaw arms 2a and 3 and on the other hand the jaw arms 3 and 2b with their approach to the closed position laterally,

If the main components 2 and 3 have approached each other sufficiently in the course of their pivoting movement in the direction of arrow 8 (cf. FIG. La), the comminution material 11 (cf. FIG. 2a, b) is not shown here under the influence of Free end portion 3a pressed against the double jaw 2 and finally by cooperation of the mutually facing cutting elements 9 and

10 severed, the free end portion 3a engaging in the space between the jaw arms 2a and 2b.

Since the central jaw arm 3 executes an evasive movement with respect to the first jaw arm 2a (in the transverse direction) under the influence of the transverse forces which act on it in the course of the cutting process, part of the Shredding material is drawn into the cutting gap between the cutting elements 9 and 10. This may lead to the fact that the driving forces generated by the hydraulic cylinders 6 and 7 are no longer sufficient to open the scrap shears 1 by moving in the opposite direction to the arrow 8. The main components 2 and 3 are thus jammed due to the static friction forces acting in the cutting gap and on the central jaw arm 3 and the second jaw arm 2b and can no longer be moved in the return stroke direction by acting on the hydraulic cylinders 6 and 7, unless explained as follows precautions will be taken that go beyond the state of the art.

As shown in FIGS. La, b and 2a, b, the scrap shear 1 designed according to the invention additionally has an abutment element in the form of a wedge element 12, to which a wear-resistant sliding plate 12a is detachably fastened by means of fastening elements (not shown) (for example fastening screws). The wedge element 12 is arranged on the second jaw arm 2b at the level of the free end section 3a, possibly displaceably, on the inner side of the jaw arm 2b, which faces the middle jaw arm 3 on its side facing away from the cutting elements 9.

As can be seen in FIG. 2a, an undesired evasive movement of the central jaw arm 3 is prevented by the fact that it is supported - in particular in the course of the cutting process - by its counter surface 3b lying on the right side on the working surface 12b of the sliding plate 12a facing it. The slide plate 12a is aligned via guide plates 13, 14 (cf. FIG. 1 a) fastened to the second jaw arm 2b in such a way that it ultimately relates to the mutual approach of the double jaw 2 and the middle jaw arm 3 in the course of the closing movement the longitudinal axis 4a of the bracket 4 assumes an almost vertical position.

The freedom of movement of the sliding plate 12a together with the wedge element 12 - to the left in FIG. 1 a - is further determined by a stop plate 15 likewise fastened to the second jaw arm 2b; in the working position indicated in FIG. 1 a, the wedge element 12 is supported laterally on the stop plate 15 and is held immovably by means of clamping screws 16 with respect to the second jaw arm 2b carrying the wedge element 12. As will be explained in more detail below, After the loosening of the clamping screws 16 and under the action of the guide plates 13, 14 with respect to the second jaw arm 2b, the slide plate 12a fastened to the wedge element 12 can also move such that - starting from the working position shown in FIG. 2a - the distance between the Slide plate 12a or its working surface 12b and the first jaw arm 2a enlarged. This is made possible by the fact that the wedge element 12 is supported via a support surface 12c on a correspondingly extending guide surface 2c of the second jaw arm 2b; the two mentioned interacting surfaces 12c and 2c are aligned (as shown in FIG. 2a) in such a way that - seen in the opposite direction to arrow 8 - they form an acute angle with the pivoting movement plane E of the scrap shears.

After all, the second jaw arm 2b and the wedge element 12 are connected to one another, for example under the action of screws and / or bolts, in such a way that the wedge element 12 can move temporarily with respect to the supporting jaw arm 2b and only a limited freedom of movement between the one shown in FIG 2a has the working position shown and a friction reduction position deviating therefrom (cf. FIG. 2b).

Fig. 2a shows - after initiation of the cutting process and the resulting mutual approximation - the position of the double jaw 2 and the middle jaw arm 3 after the crushing material 11 in the cutting gap 17 between the mutually facing cutting elements 9 and 10 of the middle jaw arm 3 and of the first jaw arm 2a has been retracted. The middle jaw arm 3 has carried out a transverse evasive movement in the direction of arrow 18 due to the transverse forces acting in the cutting gap and is supported with its counter surface 3b directly on the working surface 12b of the slide plate 12a, and thus also with the interposition of the wedge element 12, on the second Jaw arm 2b off.

The wedge element is guided on the one hand with respect to the second jaw arm 2b such that the slide plate 12a and wedge element can only execute a parallel movement in the plane of the drawing. On the other hand, under the action of the support surface 2c and the guide surface 12c, the sliding plate 12a is held on the second jaw arm in such a way that it can move parallel to itself in the plane of the drawing, as a result of which the distance between the working surface 12b and the first jaw arm 2a changes; The same applies accordingly with regard to the distance between the first jaw arm 2a and the middle jaw arm 3, as long as the latter rests on the sliding plate 12a. In the working position shown in FIG. 2a, the wedge element 12 bears on its narrow side facing away from the central jaw arm 3 against the stop plate 15 (shown in FIG. 1a).

The frictional force conditions, which are present under the action of the crushing material 11 on the one hand in the cutting gap 17 and on the other hand between the middle jaw arm 3 and the sliding plate 12a, may result in the double jaw 2 and the middle jaw arm 3 no longer being affected by the hydraulic cylinders 6, 7 Let move and the scrap shear 1 is jammed. To eliminate this clamping state, the clamping screws 16 (shown in FIG. 1 a) are first loosened, so that the slide plate 12a together with the wedge element 12 is now movably guided on the second jaw arm 2b.

As a result of the clamping force acting between the central jaw arm 3 and the sliding plate 12a, there is a non-positive connection between these parts, ie the forces driving in the opening direction of the scrap shear 1 no longer counteract the frictional force between the middle jaw arm 3 and the sliding plate 12a, but a smaller one , effective frictional force between the support surface 12c and the guide surface 2c. Accordingly, the driving forces are sufficient to move the middle jaw arm 3 relative to the double jaw 2, the sliding plate 12a together with the wedge element 12 being temporarily moved with the middle jaw arm 3 and - due to the parallel displacement of the sliding plate 12a with respect to the second jaw arm 2b - the distance between the slide plate 12a and the first jaw arm 2a is increased. This change in distance also has the consequence that the clamping force acting on the double jaw 2 and the central jaw arm 3 decreases and the overall system consisting of parts 2, 3, 12a and 12 relaxes. Fig. 2b shows in this context an operating state of the scrap shear, after - after loosening the clamping screws 16 - the double jaw 2 and the middle jaw arm 3 have been moved relative to each other in the opening direction (against arrow 8) and the slide plate 12a together with the wedge element 12 under the action of the middle jaw arm 3 (ie upwards in the illustration) has also been moved. In order to clarify the movement processes that occur, the working position of the parts 12, 12a (shown in FIG. 2a) and the associated starting position of the middle jaw arm 3 are additionally indicated by dash-dotted lines. The invention thus makes it possible to eliminate any clamping states that may occur with simple means and with little effort. The subject of the invention can in particular also be designed such that the sliding plate 12a simultaneously forms the wedge element 12 and accordingly the support surface 12c is directly part of the sliding plate 12a.

Furthermore, in the context of the invention, the middle jaw arm 3 can likewise have a wear-resistant section on its side facing the sliding plate 12a - in particular in the form of a detachably fastened wear plate. Irrespective of this, the subject matter of the invention can also be advantageously configured in such a way that the locking of the wedge element 12 or the slide plate 12a designed as a wedge element with respect to the second jaw arm 2b can be influenced remotely, for example by means of hydraulically actuated clamping cylinders. The solution according to the invention also relates to embodiments in which the slide plate 12a together with the wedge element 12 or the slide plate forming the wedge element without locking possibility, that is from the outset with a predetermined range of motion as a movable component on the second jaw arm 2b.

In the embodiment shown in Fig. 3a, b, each jaw arm 2a, 2b and 3 is equipped with an abutment element designed as a wedge element, the wedge elements differing from each other and the second jaw arm 2b with respect to its design with that in Fig. 2a, b matches. At least one of the cutting elements 10 is detachably attached to a wedge element 19, which is supported via a support surface 19a on a correspondingly aligned guide surface 20 of the first jaw arm 2a. The freedom of movement of the wedge element 19 in the direction of the supporting jaw arm 2a (ie downward in FIG. 3a) is limited by a stop surface 20a formed thereon. As already explained above, the wedge element 19 can be designed such that it can be locked in the working position (shown in FIG. 3a) by means of locking elements (not shown) with respect to the supporting jaw arm 2a. The middle jaw arm 3 is provided with a wedge element 21 in the area in which the cutting gap 17 is formed during the cutting process, which can be displaced with respect to the jaw arm 3 and, if necessary, can also be locked by means of at least one locking element, not shown. A wedge-like guide 22 held on the central jaw arm 3 projects into the cavity of the wedge element 21. In the working position shown in FIG. 3a, the inner support surfaces 21a, 21b are supported on the correspondingly aligned guide surfaces 22a, 22b of the wedge-like guide 22. The latter is designed such that it has a cross section tapering in the direction of arrow 8. On the side facing the first jaw arm 2a, the wedge element 21 is at least equipped with a cutting element 9 which is attached to it interchangeably.

3b shows an operating state of the scrap shear after which - if necessary after releasing an existing lock - the jaw arms 2a, b on the one hand and the middle jaw arm 3 on the other hand have been moved relative to one another in the opening direction (counter to arrow 8).

Since the wedge elements 12, 19 and 21 each move in the longitudinal direction with respect to the supporting jaw arm 2b, 2a or 3 during the opening movement of the scrap shears and can simultaneously perform a transverse movement, the overall system shown (also in the area of the cutting gap 17) can be corresponding relax quickly.

3a, b can also be modified such that only two of the three jaw arms 2a, 2b and 3 are equipped with wedge elements in the manner shown, for example the outer jaw arms 2a and 2b of the double jaw.

Furthermore, with a view to eliminating clamping states, it may already be sufficient, for example, to equip only the middle jaw arm with the wedge element 21. Accordingly, the first jaw arm 2a is designed according to FIG. 2a; the second jaw arm 2b has - with the elimination of the wedge element 12 - on the side facing the middle jaw arm 3 only the slide plate 12a which is held on the second jaw arm with fastening means, not shown. Any clamping states that occur can also be eliminated within the scope of the invention in that at least one jaw arm of the scrap shears has an abutment element that can be displaced transversely to the plane of the pivoting movement. 4a, b, the second jaw arm 2b is equipped on its side facing the middle jaw arm 3 with a transversely displaceable abutment element in the form of a cylinder unit 23; this essentially consists of a housing 23a fastened to the second jaw arm 2b and a piston 23b movably guided therein with a sealant 23c. The parts 23a to 23c delimit an internal chamber 23d which can be pressurized via a bore 23e by supplying a fluid or, if necessary, relieved of pressure.

The range of motion of the piston 23b with respect to the housing 23a in the direction of the central jaw arm 3 is limited by stops 24 attached to the housing 23a. On the side facing away from the chamber 23d, the piston 23b carries a slide plate 12a. As can also be seen in particular in FIG. 4b, the cylinder unit 23 and the sliding plate 12a are matched to one another in such a way that the stops 24 are in any case outside the area of influence of the central jaw arm 3.

4a, the cylinder unit 23 assumes its working position, in which the piston 23b rests against the stops 24 and the middle jaw arm 3 is supported on the working surface 12b of the sliding plate 12a via its counter surface 3b. The chamber 23d is pressurized by the supplied fluid. In contrast, FIG. 4b shows an operating state in which the piston 23b has shifted within the housing 23a (to the right in the drawing) in the direction of its friction-reducing position, as a result of which the distance, for example, between the working surface 12b and the first jaw arm 2a has increased accordingly. ^• The above-mentioned transverse movement of the piston 23b is possibly made possible and triggered by the fact that - after relieving the pressure in the chamber 23d via the bore 23e - the central jaw arm 3 executes a lateral evasive movement due to the transverse forces acting in the cutting gap 17 and thereby the pressure-relieved piston via the sliding plate 12a 23b shifts in the direction already mentioned, with the result that the overall system consisting of the jaw arms 2a, 2b, 3 and the cylinder unit 23 is relieved in particular in the region of the cutting gap 17. In the context of the invention, the embodiment according to FIGS. 4a, b can be further developed such that the cylinder unit 23 attached to the second jaw arm 2b additionally has a reset acting on the piston 23b.

This is preferably designed as a mechanical suspension and is effective in such a way that the pressure-relieved piston 23b within the housing 23a assumes the friction reduction position (to the right in the drawing).

The use of a provision can also be advantageous in that it does

Evasion movement of the middle jaw arm 3 supports and thus contributes to the relaxation of the overall system, in particular in the cutting gap 17.

It goes without saying that the cylinder unit 23 can also be double-acting in the context of the solution according to the invention, so that the piston 23b transfers through different pressurization both in the working position shown in Fig. 4a and in the pressure reducing position indicated in Fig. 4b can be.

The embodiment in question (according to FIGS. 4a, b) can also be designed according to the invention in such a way that the chamber 23d is filled with a viscous agent (in particular grease) via the bore 23e by means of a press and the bore 23e is activated in the event of a malfunction, so that the viscous agent can escape to the outside under the action of the piston 23b.

This embodiment has the advantage that it works with simple, normally already existing equipment (for example a lubricant hand press), is not very susceptible to faults and can be operated easily in the event of a fault, for example by opening a shut-off valve which opens the bore 23e and thus the chamber 23d unlocks.

The embodiment according to FIGS. 4a, b can also be simplified in the context of the invention in that the abutment element is designed to be displaceable on the one hand by means of screw elements and on the other hand to be lockable.

This can be achieved in particular in that the piston 23b is displaced and held within the housing 23a by means of adjusting screws, not shown leaves. The set screws are rotatably connected on the one hand to the piston 23b and, on the other hand, are supported on the housing 23a, so that the piston 23b either moves in the direction of the working position (FIG. 4a) or in the direction of, depending on the direction of rotation of the set screws executes the retracted friction reduction position (Fig. 4b).

Within the framework of the teaching according to the invention, the desired reduction in the frictional forces occurring under the influence of the comminution material can furthermore be achieved in that at least one jaw arm has an abutment element on its end section facing away from the holder, which is designed to be pivotable in a suitable manner with respect to the supporting jaw arm. In the embodiment according to FIGS. 5a, b, an abutment element 25 is fastened to the second jaw arm 2b, which is composed of the following components: a base plate 25a with a U-shaped cross section, a pivot plate 25b articulated on one side and a sliding plate 12a fastened thereon, and one lockable eccentric 25c, on which the pivot plate 25b is supported in an angle-variable manner with respect to the base plate 25a.

While the articulated connection (not shown) between the parts 25a and 25b is arranged on the side of the base plate 25a facing the central jaw arm 3, the eccentric 25c lies on the opposite side, the pivot plate 25b having an end face which engages more or less in the base plate 25d.

5a, under the action of the correspondingly held eccentric 25c, the swivel plate 25b assumes the working position in which the working surface 12b of the slide plate 12a is aligned parallel to the swivel movement plane E or to the first jaw arm 2a.

By suitable rotation of the eccentric 25c counterclockwise, the swivel plate 25b connected to the eccentric can be moved in such a way that the end surface 25d retracts in the direction of the base plate 25a and the swivel plate - like the work surface 12b - is oriented at an acute angle with respect to the swivel movement plane E. Starting from the working position shown in Fig. 5a, the swivel plate is transferred by rotating the eccentric 25c into the friction reduction position indicated in Fig. 5b, with the result that the distance between the working surface 12b and the first jaw arm 2a increases and thus relaxation also in Area of the cutting gap 17 is made possible.

It goes without saying that the slide plate 12a must be adapted to the pivot plate 25b in such a way that its pivoting movement with respect to the base plate 25a always results in the desired increase in distance from the first jaw arm 2a.

Furthermore, the embodiment in question presupposes that the swivel plate 25b is connected to the eccentric 25c in such a way that it is inevitably carried along when the eccentric is rotated and is alternatively swiveled in both directions with respect to the base plate 25a.

The embodiment of the subject matter of the invention shown in FIGS. 6a, b differs from the embodiment according to FIGS. 5a and 5b in that the pivot position of the abutment element 25 can be changed under the action of a screwing means - consisting of at least one adjusting screw 26. Apart from this, the pivotable abutment element corresponds to the eccentric design in terms of its design and its essential components.

Starting from the working position (FIG. 6a), in which the at least one adjustment screw 26 has its maximum screw-in depth with respect to the base plate 25a, the inclination of the swivel plate 25b together with the slide plate 12a with respect to the swivel movement plane E by rotating the at least one adjustment screw 26 and the associated one The screw-in depth can be changed continuously in the direction of the friction reduction position (Fig. 6b). The pivoting movement of the pivot plate 25b in the direction of the friction reduction position has the consequence that the distance between the working surface 12b of the slide plate 12a and the first jaw arm 2a increases. Accordingly, the middle jaw arm 3 can perform an evasive movement, in particular allows relaxation in the area of the cutting gap 17 between the cutting elements 10 and 9; this relaxation process in turn leads to the fact that the frictional forces counteracting the opening movement (counter to arrow 8) in the area between the jaw arms 2a and 3 on the one hand and 3 and 2b on the other hand become smaller and thus allow the scrap shears to be operated further. As in the case of the embodiment according to FIGS. 5a and 5b, the at least one adjusting screw 26 is rotatably connected to the swivel plate 25b in such a way that it is inevitably carried along with the movement of the adjusting screw 26 with respect to the base plate 25b, both in the direction of the working position as well as in the direction of the friction reduction position.

It goes without saying that the abutment element 25 can also be equipped with differently designed adjustment elements within the framework of the teaching according to the invention. Furthermore, it is possible according to the invention to operate the adjustment elements in question remotely by means of motor drives and to hold them in an intended position.

The advantage achieved by the invention is, in particular, that by equipping at least one jaw arm of the scrap shears or the comparable shredding device with at least one movable abutment element, the overall system formed by the jaw arms can, if necessary, be relaxed in the area in which the shredding material is acted on. Accordingly, the at least one abutment element (in each case) is arranged on the end section of the relevant jaw arm facing away from the holder and is such that the distance to the adjacent jaw arm can be increased if necessary, the outer surface of the abutment element facing away from the jaw arm carrying out a relative movement with respect to the supporting jaw arm ,

Another advantage of the solution according to the invention can be seen in the fact that any clamping condition that has occurred can be eliminated without intervention in the cutting area and, in particular, without removal and conversion measures in the area of the interacting jaw arms.

Claims

claims

1. Device on scrap shears (1) or the like - to reduce the frictional forces that occur under the action of the crushing material (11) in the course of the closing movement (arrow 8) - with several jaw arms (2a, 2b, 3), which are relative to each other a pivoting movement Can execute in the closing or opening direction of the scrap shears (1), the end sections facing away from the holder (4) of the scrap shears (1) having at least two adjacent jaw arms (2a, 3 or 3, 2b) having cutting elements (10, 9) , which together form a cutting area that narrows with the pivoting movement in the closing direction (arrow 8), and wherein the end sections of mutually adjacent jaw arms (2a, 3. or 3, 2b) overlap laterally, at least in the closed position of the scrap shears (1) by the following features: at least one jaw arm (2a, 2b, 3) is at its end section facing away from the holder (4), regardless of whether this End section is also effective as a cutting element (9, 10), equipped with an abutment element (19, 12 or 21), which - at least temporarily - move relative to the supporting jaw arm (2a, 2b, 3) between a working position and a friction reduction position can, and the abutment element is designed such that with its relative movement in the direction of the friction reduction position, the distance between its outer surface facing away from the supporting jaw arm (2a, 2b, 3) and the opposite surface of the adjacent jaw arm facing this increases.

2. Device according to claim 1, characterized in that the abutment element (12, 25) by means of a locking element (16, 26) with respect to the supporting jaw arm (2b) can be locked.

3. Apparatus according to claim 2, characterized in that the locking element is remote-controlled.

4. Device according to one of the preceding claims, characterized in that the abutment element is designed as a wedge element (12, 19, 21), which at least temporarily in the opening movement of the scrap shears (1) relative to the supporting jaw arm (2b, 2a, 3) Direction can be moved to the friction reduction position.

5.. Device according to claim 4, characterized in that the wedge element

(12, 29, 21) is supported on the supporting jaw arm (2b, 2a, 3) in such a way that the moving wedge element simultaneously executes a transverse movement parallel to itself.

6. Device according to one of claims 1 to 3, characterized in that the abutment element (23) is designed to be displaceable transversely to the plane of the pivoting movement (E).

7. The device according to claim 6, characterized in that the abutment element is on the one hand displaceable by means of screw elements and on the other hand lockable.

8. The device according to claim 6, characterized in that the abutment element is designed in the manner of a cylinder unit (23) and is displaceable by means of a pressurized fluid.

9. The device according to claim 8, characterized in that the cylinder unit (23) has a reset, the effect of which is counter to the holding force caused by the fluid.

10. Device according to one of claims 8 and 9, characterized in that the cylinder unit (23) is transferred under the action of the fluid into an operating state in which the abutment element assumes its working position.

11. Device according to one of claims 1 to 3, characterized in that the abutment element (25) with respect to the supporting jaw arm (2b) in such a way is pivotable that in the friction reduction position the distance between the then obliquely aligned abutment outer surface (12b) and the counter surface (3b) of the adjacent jaw arm (3) - seen in the closing direction (arrow 8) of the scrap shear (1) - increases.

12. The apparatus according to claim 11, characterized in that the pivot position of the abutment element (25) under the action of a screw (26) can be changed.

13. The apparatus according to claim 11, characterized in that the pivot position of the abutment element (25) under the action of an eccentric (25c) is variable.