GB2405118A

GB2405118A - Shear with actuating mechanism under tension

Info

Publication number: GB2405118A
Application number: GB0319374A
Authority: GB
Inventors: Shaun Tyas; David Stonecliffe
Original assignee: VAI Industries UK Ltd
Current assignee: Primetals Asset Management UK Ltd
Priority date: 2003-08-18
Filing date: 2003-08-18
Publication date: 2005-02-23
Anticipated expiration: 2023-08-18
Also published as: GB2405118B; GB0319374D0

Abstract

A shearing machine comprising a support frame and a pair of opposed upper and lower shear blades B, (Fig 6, D) each of which is carried by a corresponding support beam (Fig 6, C, E), and a shear actuating mechanism F, G which interconnects the two support beams directly so as to draw them together in use, whereby the shearing force (Fig 7, F) is not transmitted through the frame (Fig 5, K). Actuators K and L are used in combination with actuators G and F to effect different shearing actions. Selective operation of the actuators enables the shearing action to be achieved in a stationary horizontal plane without lifting or lowering the material cut.

Description

24051 1 8 - 1 "Compact Shear" This invention relates to shearing equipment

for the purpose of cutting flat material stock in the form of strip or plate.

Various arrangements of opposed shear blades are commonly used for cutting sheet material such as metal.

The present invention relates particularly to the method of transmitting the force necessary to shear the material from the actuating mechanism to the shear blades.

Known methods of applying the shearing force are illustrated in the following four

1 0 examples.

Example 1: Mechanical Shearing Machine.

Referring to Figures 1 and 2: A shearing force is applied to the material being sheared, A, by an upper shear blade B. fixed to a moving upper beam C. An opposing stationary lower shear blade D, is supported by a fixed lower beam E. The vertical motion of the upper shear blade and beam, and the applied force are generated by the rotation of cranks G and H. about axes 01 and 02. The motion and force is transmitted by the links I and J. The cranks are usually driven by an electric motor through reduction gears and shafts. In addition, it is usual to synchronise the rotation of the cranks by a system of interconnecting gears.

The vertical reaction to the shearing force is transmitted through the bearings of the cranks M and N and the shear frame K, to the lower beam E, thus containing and balancing the forces within the system. The complete assembly is usually supported by concrete foundations L. The relative rotation of the cranks G and H are shown in figure 1 as being in exact synchronization. With this arrangement the upper shear blade and beam will be caused to move with vertical motion whilst remaining horizontal.

Referring to Figure 1a: in some known arrangements, one crank H. is rotationally displaced with respect to the other crank G. The rotational displacement is constant throughout the complete operating cycle of the cranks. The effect of the rotational displacement of the cranks is to superimpose a rotational motion on the vertical motion of the upper shear blade, B and beam, C. This is known as "rocking" and imparts some benefit to the shearing action.

In this example, two crank and link mechanisms are shown but an arrangement using a single crank and link mechanism has also been constructed. In this case only vertical motion of the blade is achieved.

Example 2: Mechanical Shearing Machine.

Referring to Figure 3: an alternative to the machine described in example 1 is illustrated in figure 3. In this example the vertical motion of the upper shearing blade and beam, and the applied force are generated by the expansion of the hydraulic rams, A and B. Otherwise the machine is similar to that described in example 1.

The extension of the rams, A and B. is shown in figure 3 as being in synchronization. With this arrangement the upper shear blade and beam will be caused to move with vertical motion whilst remaining horizontal. The synchronization is achieved in some cases by mechanical constraints or in other cases by a feedback position control system applied to the hydraulic rams.

The reaction to the vertical shearing force is transmitted via the upper mountings M and N of the hydraulic actuators through the shear frame K which supports the lower beam E. In some known arrangements, one ram is extended and retracted in advance of the other throughout the complete operating cycle of the shearing action. The effect of the relative displacement of the rams is to superimpose a rotational motion on the vertical motion of the upper shear blade and beam. - 3

In this example, two hydraulic rams are shown but an arrangement using a single ram is also known. In this case only vertical motion of the blade can be achieved.

Example 3

Referring to Figure 4: in example 1 above the movement the shearing action is in the downward movement of the upper blade. Shearing machines utilising the same crank mechanism can also be arranged whereby the upper shear blade D, and support beam E, are stationary, the shearing action being achieved by the upward movement of the lower shearing blade B. and beam C. Such mechanisms are otherwise similar to

Example 1.

The reaction to the vertical shearing force is transmitted via the bearings of the cranks M and N. and transmitted through the shear frame K, to the upper beam E, thereby containing and balancing the forces within the system.

Example 4

Referring to Figure 5: in In example 2 above the movement the shearing action is in the downward movement of the upper blade. Shearing machines utilising the same kind of ram actuators can also be arranged whereby the upper shear blade D and beam E, are stationary, the shearing action being achieved by the upward movement of the lower shearing blade B and beam C. Such mechanisms are otherwise similar to

example 2.

The reaction to the vertical shearing force is transmitted through the lower mountings M and N of the hydraulic actuators and the shear frame K, which supports the upper beam E. The present invention seeks to provide a mechanism for applying the force and motion for the cutting of metals or other materials by a shearing action that avoids transmitting the shearing force through the frame of the shearing machine and allows greater flexibility in the operation of the machine. - 4

Accordingly the present invention provides a shearing machine comprising a support frame and a pair of opposed upper and lower shear blades each of which is carried by a corresponding support beam, and a shear actuating mechanism which interconnects the two support beams directly so as to draw them together in use, whereby the shearing force is not transmitted through the frame.

Some embodiments of the invention will now be described with reference to the examples of Figures 6 to 11.

As shown in Figure 6, the shearing force is applied to the material being sheared, A by the shear blades B and the upper beam C. The relative motion between of the upper shear blade and beam, and the lower shear blade and beam, and the shearing force, are generated by the retraction of the hydraulic actuators, F and G which are directly connected between the beams by the links H and 1. Thus the relative motion and the shearing force are transmitted directly between the upper and lower shear beams.

The large shearing force is not transmitted to any supporting frame. In this arrangement the supporting frame is incidental to the transmission of the shearing force and is therefore not shown in detail.

As shown in Figure 6, the lower shear is supported and fixed to the machine foundation, J. With this arrangement the lower beam will be stationary and the shearing action will be in a downward direction.

An alternative configuration is illustrated in the example shown in figure 8. In this configuration the upper shear beam is supported by a fixed structure K, mounted on the foundations, J. With this arrangement the upper beam will be stationary and the shearing action will be in an upward direction.

Another alternative configuration is illustrated in the example shown in figure 9. In this configuration the lower shear beam is mounted on the foundations, J. by hydraulic actuators, K and L. Consequently various combinations of cutting actuators can be - 5 achieved by extending or retracting the supporting actuators K at the same time as the shearing actuators, F and G. Some examples of possible modes of operation are as follows: 1 Expand actuators K and L in synchronization with the retraction of actuators F and G. This will effect a shearing action in an upward direction.

2 Hold the actuators K and L stationary whilst retracting the actuators F and G. This will effect a shearing action in a downward direction.

3 Retract actuators K and L at half the rate of the retraction of actuators F and G. This will effect a shearing action in an upward and downward direction without lifting or bending the material being cut.

A variation that can be operated in a similar manner is illustrated in Figure 10. In this example the upper beam is supported on hydraulic actuators, K and L. By the simultaneous operation of the actuators F and K and actuators G and L a similar range of shearing actions to the ones in the previous example can be achieved.

Another variation is illustrated in Figure 9a. This incorporates a curved shearing blade B and actuator F is retracted and extended in advance of actuator G throughout the complete operating cycle of the shearing action. The effect of the relative displacement of the rams is to superimpose a rotational motion on the vertical motion of the upper shear blade and beam. This is known as "rocking" and has some benefit to the shearing action.

If the supporting actuator K is operated in synchronization with the actuator F and the supporting actuator L is operated in synchronization with the actuator G the result will be to effect a "rocking" shearing action on the lower blade whilst holding the upper blade stationary. Thus it will cause the material to be sheared with a rocking action in an upward direction without the need to change the mechanical configuration of the shearing machine. - 6

In the example of Figure 11, the hydraulic actuator F is extended in advance of hydraulic actuator G during the cutting stoke of the shearing action. The effect of the relative displacement of the rams is to cause the blade B to shear the material in the same way as an inclined blade, without the need to change the blade to a special inclined one. By changing the position control of the hydraulic actuators the shearing machine can be quickly changed to produce a vertical shearing action with horizontal blade as shown in figure 6, or an inclined blade shearing action as shown in Figure 11.

The above example refers to hydraulic actuators, but it will be appreciated that the same effect can be achieved by any other type of actuator, for example, mechanical, pneumatic, or electrical.

Claims

_ CLAIMS

1. A shearing machine comprising a support frame and a pair of opposed upper and lower shear blades each of which is carried by a corresponding support beam, and a shear actuating mechanism which interconnects the two support beams directly so as to draw them together in use, whereby the shearing force is not transmitted through the frame.

2. A shearing machine according to claim 1 in which the lower shear beam is fixed to the support frame so that the shearing action is downwards.

3. A shearing machine according to claim 1 in which the upper shear beam is fixed to the support frame so that the shearing action is upwards.

4. A shearing machine according to any preceding claim in which the shear actuating mechanism comprises a pair of link mechanisms including variable actuators which interconnect spaced-apart points on the two support beams.

5. A shearing machine according to claim 1 in which one of the shear beams is connected to the support frame by at least one variable actuator so as to allow one of the shear blades to be inclined during the cutting operation by selective operation of the shear actuating mechanism and the supporting variable actuator or actuators.

6. A shearing machine according to claim 5 in which the said one shear beam is supported on the support frame by a pair of spaced-apart supporting variable actuators, whereby selective operation of the interconnecting actuators in one direction, and compensating operation of the supporting actuators in the opposite direction, enables the shearing action to be achieved in a stationary horizontal plane without lifting or lowering the material cut.

7. A shearing machine according to any preceding claim in which the blade is curved to allow cutting with a rocking motion and/or by selective operation of the shear actuating mechanism. l - 8

8. A shearing machine substantially as herein described with reference to ay of Figures 8 to 11 of the accompanying drawings.