GB2075899A

GB2075899A - Rotatable cropping shear assembly

Info

Publication number: GB2075899A
Application number: GB8114446A
Authority: GB
Original assignee: Schwermaschinenbau Kombinat Ernst Thalmann VEB
Current assignee: Schwermaschinenbau Kombinat Ernst Thalmann VEB
Priority date: 1980-05-16
Filing date: 1981-05-12
Publication date: 1981-11-25
Also published as: IT1167755B; SE8103004L; IT8121757A0; DE3113036A1

Abstract

The invention relates to a rotatable cropping shear assembly for cropping high-speed rolled stock in wire mills, wherein the rolled stock is brought by means of a pivotable tube 6 laterally into the blade region 4 of blade head members 3 and 5 which are mounted in overhung manner and have helical grooves, and severed perpendicularly to the longitudinal axis of the stock material by the rotating blades 4. The invention achieves synchronisation in respect of the required transverse movement of the pivotable tube, with the transverse speed of the helical grooves in the blade head member by having the pivotable tube 6 connected by way of an alternating-stroke transmission means 11 and a transmission means 9 to the shears assembly drive, fixedly in respect of speed of rotation. <IMAGE>

Description

SPECIFICATION Rotating cropping shears assembly The invention relates to a rotating cropping shears assembly for high-speed rolled stock in wire mills, wherein the rolled stock is brought by means of a pivotable tube laterally into the blade region of blade head members having helical grooves and which are mounted in an overhung manner, and severed perpendicularly to the bar axis by the rotating blades, the lateral movement of the pivot tube corresponding to the speed of the transverse movement of the helical grooves of the blade head member.

To comply with the technical requirements for the production of rolled wire lashings which are ready for sale, it is necessary for the wire which is produced to be cropped. With the rolling speeds which are used at the present time, of more than 50 metres/second, only so-called high-capacity shears assemblies are used for this purpose.Thus, shears assemblies are known, which provide for guiding the wire leader in front of the shears assembly with special forms of switch points means, as described in DD-WP 129127, or by means of a pivot tube, as described in DD-WP B 23 D/215 596, gripping the wire leader in the blade head members by means of screwthread-like grooves and lateral movement with respect to the blades, severing the wire on the principle of the drum shears assembly, and conducting the cropped end and the stock leader away separately in different paths in the discharge portion.

Tests in respect of these alternative forms of shears assembly revealed technical disadvantages which made it impossible to achieve high-quality cropping. This disadvantage occurred primarily because the necessary synchronisation between the transverse movement of the helical grooves in the blade head member and the transverse movement of the wire leader in the switch points means or the transverse movement of the pivot tube, in respect of time, could not be achieved. This resulted in the wire being repeatedly caught in the groove boundaries in the blade head members, and rupture of the rolled wire in the wire guide means upstream of the shears assembly. In such situations, trouble is inevitable, so that the entire rolling line comes to a halt.

The problem of the invention is to achieve synchronisation in respect of the required transverse movement of the pivot tube, with the predetermined transverse speed of the screwthread-like grooves in the blade head member.

According to the present invention there is provided a rotatable cropping shears assembly for cropping high speed rolled stock in wire mills, comprising a pair of rotatable cutter heads provided with helical grooves in which cutter blades are located, a swingable pipe through which the material to be cropped is fed to the cutter blades, to be severed perpendicularly to the longitudinal axis of the rolled stock by the rotating blades, the lateral movement of the pivotable tube corresponding to the speed of transverse movement of the helical grooves of the cutter heads, the pivotable tube being connected by way of an alternating-stroke transmission means and a drive transmission means, fixedly in respect of the speed of rotation thereof, to the shears assembly drive.

In order to achieve the reversible pivotal movement of the pivot tube, a shift clutch means is arranged between the alternating-stroke transmission means and the shears assembly drive.

The invention further provides that a support roller which moves on a curved guide track is arranged below the pivot tube at the wire discharge end, for producing the lifting and pivotal movement.

An embodiment of the invention will now be described, by way of an example, with reference to the accompanying drawing, in which: Figure 1 shows a plan view of the shears assembly; and Figure 2 shows a view in section taken along line A-A indicated in Figure 1.

Figure 1 shows the motor 1 with the shears assembly 2 and the upper blade head member 3 and the blade 4 mounted thereon. Arranged upstream of the blade heads 3 and 5, at the wire discharge end, is a pivotable tube 6 which is mounted at one end in a Cardan joint 7, while a discharge means 16 is arranged downstream of the blade heads 3 and 5. A drive transmission means 9 which is driven in a rotational speed-dependent mode directly by the shears assembly is connected to the shears assembly 2 by coupling means 8. At the output side of the transmission means 9 is a shift clutch means 10 for driving an alternating-stroke transmission means 11.

The stroke connecting rods 12 of the transmission means 11 are connected to the pivotable tube 6 by way of a pair of universal-joint shaft coupling means 13.

Figure 2 shows the upper blade head 3 and the lower blade head 5 with the blades 4. A support roller 14 which is arranged belowthe pivotabletube 6 is disposed in the starting position on a guide track 15 which is of a curved configuration.

The mode of operation is as follows: By means of an electrical pulse which is triggered by the leader tip, the clutch means 10 is engaged and the transmission means 11 draws the pivotable tube 6 towards the left, as viewed in the rolling direction, by way of the stroke connecting rods 12 and the pair of universal joint shaft coupling means 13. When this occurs, the pivotable tube 6 is moved by the support roller 14 on the guide track 15, over a predetermined curved path. In this respect, the speed of movement of the pivotable tube 6, for each speed of rotation of the blade head members 3 and 4, precisely corresponds to the transverse speed of the pass grooves 17, as the transmission means 9 and the stroke transmission means 11 are coupled to the shears assembly drive for rotation at the same speed. The rolled wire is thereby reliably guided into the region of the blades 4 by the grooves 17, and severed. After the connecting rods 12 reach their limit position, the clutch means 10 is disengaged by the making of contacts. When the end of the wire has passed through the pivotable tube 6, a further electrical pulse is triggered, which actuates the clutch means 10 and sets the reversed alternating stroke transmission means in movement. The connecting rods 12 are now moved towards the right, as viewed in the direction of rolling, and the pivot tube 6 is moved into the starting position. When the connecting rods reach their limit position, contacts are made, for disengaging the clutch means 10 and reversing the transmission means 11.

Claims

1. A rotatable cropping shears assembly for cropping high speed rolled stock in wire mills, comprising a pair of rotatable cutter heads provided with helical grooves in which cutter blades are located, a swingable pipe through which the material to be cropped is fed to the cutter blades, to be severed perpendicularly to the longitudinal axis of the rolled stock by the rotating blades, the lateral movement of the pivotable tube corresponding to the speed of transverse movement of the helical grooves of the cutter heads, the pivotable tube being connected by way of an alternating-stroke transmission means and a drive transmission means, fixedly in respect of the speed of rotation thereof, to the shears assembly drive.

2. A rotatable cropping shears assembly as claimed in claim 1, in which the pivotable tube is connected by way of a pair of universaljoint shaft coupling means, to the connecting rods of the stroke transmission means.

3. A rotatable cropping shears assembly as claimed in claim 1 or claim 2, in which a shift clutch means is arranged between the stroke transmission means and the drive transmission means.

4. A rotatable cropping shears assembly as claimed in any preceding claims, in which a support roller is arranged below the pivotable tube at the wire discharge end thereof.

5. A rotatable cropping shears assembly as claimed in claim 4, in which the support roller is associated with a curved guide track.

6. A rotatable cropping shears assembly substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.