DE2532704A1 - TABLE SHEARS - Google Patents

Description

Dr. Joachim Rasper ^{IIam 1}

Patent attorney 62 Wiesbaden

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Haemmerle AG Zofingen
Switzerland

Guillotine shears

The invention relates to guillotine shears with a fixed lower knife and a pivotable upper knife, which during the Cutting movement is guided at a certain distance from the lower knife. Plate shears of the type mentioned are used for Cutting of sheets made of steel and other metals as well as for cutting plates made of other materials used.

Table shears with a fixed lower knife and a swiveling upper knife are usually used for the execution of a rotating cut and are usually hydraulic

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actuated. In a known manner, the cutter bar is such Guillotine shears stored in special bearings, which are built into the side stands of the guillotine shears. To achieve a rotating or swing cut is the axis of rotation of the cutter bar or upper cutter around one shifted a predetermined amount relative to the fixed lower knife upwards, so that the cutting direction is easy is directed obliquely downwards. The rotating movement directly supports the clearing of the cut edges after the cut and the repulsive cutting force component is reduced.

Exact knife guidance is only possible, however, if the upper knife is a while against the lower knife the cutting movement has narrowly limited play. This requires a backlash-free mounting of the axis of rotation of the pivotable Upper knife.

In order to make the axle bearing play-free, it has already been proposed to provide a play compensation, which consists in the arrangement of a pressure element that acts transversely to the axis of rotation on the cutter bar. Adjustable Pre-tensioned disc springs have proven to be useful for this.

The absolutely backlash-free mounting of the axis of rotation of the upper knife also has disadvantages. During the cutting process Tiny metal particles often stick to the edge of the sheet metal when it moves upwards of the upper knife are jammed. This causes sudden stresses and damage the knife edge. This damage occurs mainly in the case of the rotating cut described

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because the gap between the knives increases immediately after the cut, due to the reverse sequence of movements when going up the upper knife again but when passing the lower knife again except for the play-free the set cutting distance is suddenly reduced.

The aim of the invention is therefore a guillotine shear that does not have these disadvantages, although a rotating
Cut can be carried out with a cutting distance that can be adjusted without play, in which, however, the upper knife does not have to be brought unnecessarily close to the chamfered lower knife when swiveling up.

This goal is achieved by using plate shears
fixed lower knife and swiveling upper knife, which during the cutting movement at a predetermined distance
is guided by the lower knife, which is characterized in that a displacement member is present, which
periodically with the upward movement of the upper knife
this moves in relation to the lower knife in the sense of an increase in the knife play.

To adjust the cutting distance, a resiliently flexible acting transversely to the axis of rotation of the upper cutter is required
Pressure element, available, which cancels the bearing play of the axis of rotation in the horizontal plane. The sliding element according to the invention, acting transversely on the axis of rotation of the upper knife, is under the influence of the scissors actuation, so that in each case during the upward movement of the upper knife, the axis of rotation counteracts the action of the pressure element in
their storage is postponed. In this way, the knife play is increased to a predetermined value.

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Appropriately, the shaft journal is the axis of rotation of the upper knife, which with play in the horizontal Direction in a bearing takes up, flattened along horizontal sectional planes, with in the bearing spaces Crescent-shaped guide elements are used, which on their side facing the pin a have flat sliding surface, along which the pin under the action of the pressure element opposite the Camp is displaceable. According to a particular embodiment, the flattened pin can have a central transverse bore have, in which a piston supported against the bearing inner surface is inserted.

In the following, three exemplary embodiments of the invention are described in greater detail with reference to the accompanying drawings explained:

It represent

Fig. 1 shows the schematic design of a shaft bearing of the guillotine shears in side view, or on average,

Fig. 2 shows a variant of the storage with more details and

3 shows a further variant in horizontal section.

The Tafelsch, shown only schematically in Fig. 1 e re is provided with a swiveling upper cutter 1 and a fixed lower cutter 2. The upper knife 1 is attached on both sides to a knife arm 3, wherein in Fig. 1 only one knife arm is shown. the

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pivotable mounting of the knife arm 3 takes place by means of self-aligning bearings 4, in which a pin 5 of the axis of rotation of the knife arms is accommodated. The dimensions of the self-aligning bearings and the journals 5 are chosen so that a play s remains in the horizontal direction. To cancel this play, the pin 5 is under the influence of a horizontally acting force P ₁ , which is shown only schematically in the drawing by an arrow. The more detailed design of such a lash adjuster is known from Austrian patent 259-343. In the position shown, the game s is dimensioned in the horizontal direction so that there is only a small gap between the upper cutter and the lower cutter 2, which corresponds to the cutting distance.

The pin 5 is along horizontal cutting planes flattened, as indicated by the arrows 6. Crescent-shaped guide segments 7 are inserted into the spaces between them and face the pin Side each have a flat sliding surface in turn along the arrows 6. In this way it is made possible that the pin 5 in the bearing 4 can be moved in the horizontal direction until the clearance s.

Provisions are made that during the upward movement of the upper knife 1, so after the cut, the pin 5 is moved against the action of the play compensation P ₁ along the sliding surfaces of the segments 7, so that the distance between the upper knife and lower knife 2 by the predetermined value of s is increased.

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There are various possibilities for moving the pin 5 given. According to the embodiment shown in FIG. 2, the pin 5 is axially Bore 8 is provided which opens into a transverse bore 9 in which a piston 10 is received. The piston 10 is designed so that its surface 11 facing away from the transverse bore 9 is cambered and against the inner one Ring 12 of the journal bearing 4 is supported. Through the hole 8 takes place at the appropriate time, i.e. after completion Section, the application of a pressure medium, so that the pin 5 moves in the horizontal direction, whereby the knife play corresponding to the cutting distance is increased by the amount of the bearing play s.

The knife arms 3 are directly connected to the bearing 4 and the entire bearing 4 is held so that it can be displaced relative to the pin ö by the amount of the bearing play s. A spring pressure P- acts on the rollers 13, which are supported against the outer bearing ring 14. The bearing play s is canceled as soon as the piston 10 is depressurized, whereby the upper knife 1 is held by the lower knife 2 at the cutting distance. By renewed supply of pressure through the bore 8 after the cut with the upward movement of the upper cutter, the bearing 4 is brought back into the position shown, so that the bearing clearance s increased distance between the upper cutter and lower cutter.

A variant can be seen from FIG. 3. The knife shaft 15 carries a pin 16 which has an extension 17 possesses, which takes place in a camp 18 with 19 Lgerspiel. A cutter bar 20 is mounted on the pin 16,

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which to compensate for play, under the pressure of a spring 21 stands. The spring 21 acts in the direction of the arrow 22. Against the extension 17 of the pin 16 is supported in a a connecting rod 24 mounted pressure roller 23. The connecting rod 25 carries a piston 26 which is accommodated in a cylinder 27. The pressurized one Piston 26 counteracts spring 21. The control of the piston 26 takes place in such a way that when descending of the cutter bar 20 releases the spring 21 to compensate for the bearing play and to reduce the knife spacing can work. When moving up the cutter bar 20, the piston 26 is hydraulic or pneumatic The medium is applied so that the force of the spring 21 is overcome. The knife play is during the upward movement of the cutter bar increased, since the pin extension 17 advanced by the amount of the bearing play 19 will.

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Claims (4)

Patent claims: 1.! Plate shears with fixed lower knife and swiveling oversize, which during the cutting movement in a predetermined Distance from the lower blade is guided, characterized in that a displacement member (10; 25, 26) is present, which periodically with the upward movement of the upper knife (1) this relative to the lower knife (2) in the sense of increasing the knife play (s). 2. guillotine shears according to claim 1, in which for setting the cutting distance a transverse to the axis of rotation of the upper knife resiliently acting pressure member (21) is present that the bearing play (19) the axis of rotation (5, 15) in the horizontal plane, characterized in that the transverse to the axis of rotation (5, 15) of the upper knife (1) effective displacement element (10, 25, 26) is under the influence of the scissors actuation and with the upward movement of the upper knife (1) the axis of rotation (5, 15) moves against the influence of the pressure element (10, 25, 26) in its bearing (4, 18). 3. Guillotine shears according to claims 1 and 2, characterized in that the shaft journal (5) of the axis of rotation of the upper knife, which is accommodated with play (s) in the horizontal direction in a bearing (4), is flattened along horizontal cutting planes (6) , with crescent-shaped guide segments (7) being inserted into the bearing spaces, each of which has a flat sliding surface on its side facing the pin, along which the _{pin (5) under the action of the pressure element (P 1} ) can be displaced relative to the bearing (4) is. 609826/0623 4. Plate shears according to one of claims 1-3, characterized in that that the flattened pin (5) has a central transverse bore (8) in which an aich against the bearing inner surface supporting piston (10) is inserted. 609826/0623