GB2087781A

GB2087781A - Sheet shearing apparatus

Info

Publication number: GB2087781A
Application number: GB8132358A
Authority: GB
Original assignee: Mengele and Soehne Maschinenfabriken Karl GmbH
Current assignee: Mengele and Soehne Maschinenfabriken Karl GmbH
Priority date: 1980-10-27
Filing date: 1981-10-27
Publication date: 1982-06-03
Also published as: BE890878R; ATA452181A; IT1139573B; GB2087781B; DE3040422A1; DE3040422C2; IT8124734A0; NL8104855A; JPS57102718A

Abstract

Sheet shearing apparatus has a shearing frame 3 comprising a shearing table (5) and an upper blade (7b) which is movable relative to a fixed lower blade (7a). A supporting table 1, which is several times longer than the upper blade and is associated with the shearing table (5), is located outside the shearing frame (3). The frame 3 is longitudinally displaceable on guide rails 14 and is also supported by a drivable undercarriage and the lower blade 7a is secured either longitudinally on the shearing table 5 or along the whole length of the supporting table 1. A rotatable cutting tool 30 is arranged to be raised and lowered in sliding guides on the strand and so that the cutting line of the blade is parallel to the direction of the cutting edges of the blades 7a,7b in front of the shearing table 5. <IMAGE>

Description

SPECIFICATION Sheet shearing apparatus The invention relates to a sheet shearing apparatus comprising an upper blade moved against a fixed lower blade, and a shearing table.

Compared with blades such as circular saws rotating about an axis, sheet metal can be cut with guillotine shears in a fraction of the time required for rotating blades and with a far longer working life of the blades whereas with wide sheet metal cut sections the resultant stresses scarcely affect the edge zones, in the case of narrow sections they are an important factor. In particular, sheet metal strips up to 10-12 times the sheet thickness generally bend and become bowed to such an extent that they can be restraightened only with difficulty.In principle, therefore, both types of machines are required for producing sheet metal sections of any desired size, and in order to cut metal sheet into wide and narrow sheet sections the said metal sheet must be worked in turn on both machines which, apart from the machine expense involved, necessitates larger working surfaces and transporting means.

A disadvantage of guillotine shears however is that they can be designed and made only up to a length of 6 or at most 8 metres. Even at such lengths the table and blade face are subjected to particularly sever bending fracture stresses which can increase a thousand-fold at a distance. The deflection is further increased by the necessary toe dog on the table.

Compensation of the deflection would be extremely costly. The resultant inaccuracies have therefore had to be accepted and taken into account.

Also, the material involved has an adverse effect in the case of long guillotine shears. For example, the weight of a guillotine shears of 12 metres would be doubled compared with one of only 8 metres.

For all these reasons guillotine shears have hitherto rarely been constructed longer than 6 to 8 metres.

For many purposes and also having regard to continuous working far larger table lengths would however be advantageous.

A further disadvantage of guillotine shears with upper and lower blades is that when producing relatively narrow sheet metal strips the latter will bend and warp in a quite arbitrary manner, and can be restraightened only with difficulty. The far shorter working life of the blades compared with circular saws is a further disadvantage.

With circular blades on the other hand, which have also already been designed as roller baldes to be continuously displaceable in the cutting line of a metal sheet with the aid of a carriage, the unfavourably large cutting angle, which is between 300 and 60 , is a disadvantage. Also, separated large metal sheet sections are, as opposed to guillotine shears, bent downwards to a great extent.

The object of the invention is to obviate the above disadvantages and provide sheet shearing apparatus which utilises the advantages of both cutting devices in a combined form.

This objective is achieved according to the invention and is characterised in that a supporting table several times longer in relation to the upper blade length of the guillotine shears is associated with the shearing table of the guillotine shears outside the shearing frame and the stand of the guillotine shears is longitudinally displaceable via sliding parts in guide rails arranged along its length and is on the other hand supported on the ground by a drivabie undercarriage in a guide rail or in a guide gear rack, wherein the fixed lower blade is secured either longitudinally on the shearing table or longitudinally along the whole length of the supporting table and toe dogs having a corresponding action on the shear table or against the supporting table are provided and on one of the two sides of the shears frame at least one cutting tool rotating about an axis such as a circular blade with a carriage and an adjustment device is arranged so as to be able to be raised and lowered in sliding guides on the stand of the guillotine shears, and in that the cutting line of the circular blade is parallel to the direction of the cutting edge of the guillotine shears in front of the shearing table.

It is immediately clear that on account of the resultant possible step-wise operaton of the guillotine shears, which consists in the cutting of a partial cutting line, in the further movement of the shears along the supporting table by a length corresponding to the upper blade, and then again of the next cut, only a small force is required to move the cutting means, which is also reflected in the weight of the guillotine shears, and that on account of the short supporting lengths only practically negligible deformations can still arise, with the result that the guillotine shears according to the invention can now be designed and operated without any restriction as regards length. Deformations can also no longer occur on the cut-off sheet metal sections themselves since they are always cut with the same small cutting angle.

A further advantage of the invention is that an existing table can be lengthened as required, or the table length can even be shortened if necessary. The guillotine shears according to the invention can thereby also be adapted to slightly varying requirements.

To cut off narrow sheet metal strips, according to the invention the circular blade is used. Since in this connection the strips are bent only along one side, it is relatively easier to restraighten them and the blades of the guillotine shears are preserved, having regard to their fairly short working life when cutting relatively narrow sheet metal strips, whereas instead the guillotine shears are used for cutting relatively wide sheet or panel sections, and in this connection operate many times quicker than the circular blade.

The invention will now be described, by way of example and in more detail, with reference to the accompanying drawings, in which: Figure 1 shows sheet shearing apparatus according to the invention as seen from the rear side of the supporting table; Figure 2 is a side view of the guillotine shears shown in Figure 1; and Figure 3 is a side view of the guillotine shears shown in Figure 1, but viewed from the other side.

In the drawings, in Figures 1 and 2 a supporting table is denoted by the reference numeral 1 and a metal sheet lying thereon by the reference numeral 2.3 is a C-shaped frame whose opening 4 is arranged opposite the supporting table 2. A narrow shearing table 5 (see Figure 2) is arranged at the same height as the supporting table and underneath the opening 4; a toe dog is arranged above the shearing table 5. A fixed lower blade 7a is provided on the rear of the shearing table 5. An upper blade 7b co-operating with the lower blade 7a is arranged on a ram 8, which latter is arranged in a heightadjustable manner on a drive arm 11 via two spindles 9 and spindle nuts 10. The side arms 11 a and 11 b of the drive arm are rotatably mounted in joints 12 on the shears frame 3 and are driven by a cylinder piston unit 13 driving the rear cross-bar of drive arm 11 c.

According to the invention, the guillotine shears length is only a fraction of the length of the supporting table, as is illustrated in Figure 1. Guide rails 14 in which sliding rollers 15 connected to the guillotine shears frame 3 are mounted in a longitudinally displaceable manner, extend along the whole length of the supporting table at the front side thereof. On the floor, the guillotine shears frame 3 together with a drive pinion 16 are supported in a rail 17 with a guide gear rack. One of the drive pinions 16 is driven from a drive motor 18 via a universal shaft 19. The drive motor 18 drives, via a further universal shaft 20, a drive pinion 21 which engages with a guide gear rack of the guide rail 14b.Brackets 24 which can disengage in a telescopic manner from housings 23 are distributed on the longitudinal side of the supporting table 1 and arranged beneath the guide rail 14b.

Transverse grooves 25 in which clamping cylinders 26 are held in a sliding manner, and with which the metal sheet 2 is held by the sheet edge opposite the strip being cut off, are provided on the upper side of the table.

The operation of the guillotine shears according to the invention is illustrated in Figure 1, the left-hand side of which shows the position after the first cut of the sheet 2. The guillotine shears is now driven to the right by means of the drive pinions 16 and 21 to the second cut in the cutting line - arrow a - and a further piece of the metal strip 2a is cut off. As soon as the guillotine shears has passed the brackets 24b and 24c, the latter automatically extend outwardly so that they support the cut-off metal strip 2a, like the bracket 24a.As soon as the guillotine shears has reached the right-hand side - as indicated by the dotted lines - the ram 8 together with the lower blade 7a is brought via the drive (not illustrated) of the spindle nuts 10 to the opposite angular position, and after insertion of the metal sheet 2 into the frame opening 4 a further strip is cut off in the opposite working direction - arrow b.

According to the invention, a circular saw 30 with its housing 31 in which also the drive thereof is installed, is arranged on the right-hand side on the frame 3 of the guillotine shears. The housing 31 can be vertically adjusted on sliding rails 32a and 32b (Figure 2), and 33 denotes a hydraulic piston cylinder unit for the feed.

According to Figures 1 and 3, a horizontally revolving milling head 35 is arranged so as to be able to be raised and lowered in the vertical direction, in exactly the same manner on the other side.

Without necessarily limiting the scope of the invention claimed, preferred embodiments of the invention may be summarised as follows.

1. Cutting shears with an upper blade moved against a fixed lower blade and a shearing table, characterised in that a supporting table (1) several times longer in relation to the upper blade length of the guillotine shears is associated with the shearing table (5) of the guillotine shears outside the shearing frame (3) and the stand (3) of the guillotine shears is longitudinally displaceable via sliding parts (15 and 21) in guide rails (14) arranged along its length and is on the other hand supported on the ground by a drivable undercarriage (16) in a guide rail (14) or in a guide gear rack (17), wherein the fixed lower blade (7a) is secured either longitudinally on the shearing table (5) or longitudinally along the whole length of the supporting table (1) and toe dogs (6) having a corresponding action on the shear table or against the supporting table (1) are provided and on one of the two sides of the shears frame (3) one cutting tool rotating about an axis such as a circular blade with a carriage and an adjustment device is arranged so as to be able to be raised and lowered in sliding guides on the stand of the guillotine shears, and in that the cutting line of the circular blade is parallel to the direction of the cutting edge of the guillotine shears in front of the shearing table.

2. Cutting shears according to Summary 1, characterised in that a milling head similarly arranged in a vertically displaceable manner on a carriage, and which if necessary can also be laterally displaced in the direction of the sheet edge, is provided on the side of the guillotine shears frame opposite the circular blade.

Claims

1. Sheet shearing apparatus comprising a shearing table and an upper blade movable relative to a lower blade, characterised in that a supporting table (1) several times longer than the upper blade (7b) is associated with the shearing table (5) outside a shearing frame (3), a stand is longitudinally displaceable and supported on a drivable undercarriage (16) so that the fixed blade (7a) is secured longitudinally of the supporting table (1) or the shearing table (5), and in that a cutting tool rotatable about an axis is disposed on one of the two sides of the shearing frame (3) and is adjustable so as to be raised or lowered on the stand and so that the cutting line of the circular blade of the cutting tool is parallel to the direction of the cutting line of the edges of the blades (7a, 7b) in front of the shearing table.

2. Sheet shearing apparatus as claimed in Claim 1, characterised in that the stand is longitudinally displaceable in guide rails (14) disposed along its length.

3. Sheet shearing apparatus comprising a shear ing table and an upper blade which is movable relative to a lower blade, characterised in that a support table (1) several times longer than the u upper blade is associated with the shearing table (5) outside the shearing frame (3), and a stand is longitudinally displaceable in guide rails (14) arranged along its length and is on the other hard supported on the ground by a drivable undercarriage (16) in a guide rail (14) or in a guide gear rack (17), wherein the fixed lower blade (7a) is secures either longitudinally on the shearing table (5) or longitudinally along the whole length of the supl)ort- ing table (1), and toe dogs (6) having a correspor ding caction on the shearing table or against the supporting table (1) are provided, and a cutting t zol rotatable about an axis such as a circular blade \with a carriage is disposed on one of the two sides of the shearing frame (3), and an adjustment device is arranged so as to be able to be raised and lowered in sliding guides on the stand, and so that the cutting line of the circular blade is parallel to the direction of the cutting edge of the guillotine shears in front of the shearing table.

4. Sheet shearing apparatus as claimed in any one of Claims 1 to 3, characterised in that a milling head (35) is arranged in a vertically displaceable manner on a carriage provided on the side of the frame.

5. Sheet shearing apparatus as claimed in Claim 4, characterised in that the milling head (35) is arranged to be laterally displaceable in the direction of the edge of a sheet being sheared.

6. Sheet shearing apparatus constructed and arranged to operate substantially as hereinbefore described with reference to the accompanying drawings.