GB2323058A

GB2323058A - Cutting mechanism.

Info

Publication number: GB2323058A
Application number: GB9805324A
Authority: GB
Inventors: David Martin Fox
Original assignee: STRESSLINE
Current assignee: STRESSLINE
Priority date: 1997-03-13
Filing date: 1998-03-13
Publication date: 1998-09-16
Also published as: GB9805324D0; GB9705183D0

Abstract

A cutting mechanism comprises at least two pivotal arms (19, 20). A first arm (19) is pivotally mounted on a base member (10) and a second arm (20) is pivotally mounted on the first arm. A cutting device (18) is carried on the second arm (20), and drive means (22,26) are associated with the pivots between the base member (10) and the first arm (19) and between the first and second arms (19,20) for effecting a pivoting action of the arms (19,20) and to position and move the cutting device (18) in a selected manner during a cutting movement. Control means is provided for controlling the operation of the cutting mechanism to achieve a selected movement of the cutting device (18). The drive means (22, 26) for pivoting the arms (19, 20) are controlled by the control means in a preselected manner and the control means is controlled having regard to different parameters of the cutting device (18) such as speed of cutting and drive torque.

Description

CUTTING MECHANISM This invention relates to cutting mechanisms, in particular to cutting mechanisms in which a cutting element is moved through a work piece in a controlled manner during a cutting operation.

In cutting through work pieces ofrelatively large dimensions, such as during the use of rotary saws to cut concrete products, it has been proposed to use cutting elements mounted for movement along linear guides. However such mechanisms are subject to excessive wear due to the presence of dust particles and control ofmovement of the cutting element is restricted.

It is an object of the invention to provide an improved cutting mechanism in which disadvantages of prior mechanisms are overcome.

According to the invention there is provided a cutting mechanism comprising at least two pivotal arms, a first arm being pivotally mounted on a base member and a second arm being pivotally mounted on the first arm, a cutting device carried on the second arm, drive means associated with the pivots between the base member and the first arm and between the first and second arms for effecting a pivoting action of the arms and to position and move the cutting device in a selected manner during a cutting movement, and control means for controlling the operation of the cutting mechanism to achieve a selected movement of the cutting means, the drive means for pivoting the arms being controlled by the control means in a preselected manner and the control means being controlled having regard to different parameters of the cutting device such as speed of cutting and drive torque.

Preferably the cutting mechanism has drive means mounted on the second arm for effecting drive of the cutting means which is usually in the form of a rotary cutting means such as a rotary saw or a band saw. Alternatively the cutting means may be reciprocal and, for example, in the form of a hacksaw.

The drive means for the cutting means inay be an electric motor having a belt drive to the cutting means, the motor being mounted on the second arm.

The base member may be movable to change the position of the mechanism in relation to a work piece and for this purpose the base member may be a mobile frame or a tractor unit.

The connection between the first arm and the base member may include a pivot to enable the first arm to pivot about an axis at a right-angle to the pivotal connection between the first arm and the base member.

The control means may be pre-programmed to give the desired movement of the cutting device, for example a linear movement of a preselected distance, an arcuate movement, a combination of linear and arcuate movements, or any other selected movement.

The cutting mechanism may include more than two pivotal arms and for each pivot drive means may be provided to effect the selected movement of the cutting device. The drive means for the arms may comprise hydraulic cylinders, rotary actuators, electric motors, or any other suitable drive means.

Further features of the invention will appear from the following description of an embodiment of the invention given by way of example only and with reference to the drawings, in which: Fig 1 is a cutting mechanism showing the cutting device in one position, Fig 2 is a view corresponding to Fig 1 with the cutting element in another position and, Fig 3 is an end view of the mechanism of Figs 1 and 2.

Referring to the drawings there is shown a cutting mechanism intended primarily to cut preformed lengths of concrete but the mechanism can be readily adapted for other purposes.

The mechanism comprises a mobile frame 10 mounted for movement along tracks 11 carried on a base 12. The frame 10 is generally rectangular having uprights 13 at each corner and on the lower ends of each upright 13 is carried a rotatable wheel 14 engaging with a track 11.

Upper cross members 15 interconnect the upper ends of the uprights 13 and intermediate cross members 17 interconnect the uprights 13 at opposite ends of the frame 10.

Cutting means 18 is attached to the frame through a first arm 19 and a second arm 20, the first arm 19 being mounted through brackets 21 to an upper cross member 15 at one end of the frame 10.

A rotary actuating mechanism 22 is carried by the brackets 21 and is arranged to rotate the first arm 19 about a horizontal axis 23 relative to the frame 10. The rotary actuator 22, in the form of a hydraulic rotary actuator, as shown, has output shafts 24 extending from each end and on each shaft 24 is mounted a link member 25 of the first arm 19. The outer end of each link 25 is coupled to a further rotary actuator 26, output shafts 27 of which extend from opposite ends of the rotary actuator 26 and are connected to a pair of links 28 forming the second arm 20 so that the arm 20 rotates about an axis 29 of the actuator 26.

The cutting means 18 is located at the outer end of the second arm 20 for rotation about an axis 31 extending parallel to the axes 23 and 29.

The cutting means 18 in this case takes the form of a rotary disc having cutting elements'(not shown) which may be carborundum or diamond faced. The second arm 20 carries a drive motor 32 for the cutting means 18 mounted on a cross piece 33 extending between the links 28. The output shaft of the drive motor 32 drives a belt drive 33 for transmitting drive to a shaft 34 on which the cutting means 18 is carried. It will be appreciated, however, that other drive arrangements may be used for driving the cutting means 18, for example the cutting means 18 may be directly driven by a motor. Moreover the motor may be an electric motor, a hydraulic motor or a pneumatically operated motor. Instead of the cutting means being a rotary disc it may take the form of a bandsaw, a hacksaw or other kinds of cutting devices.

The rotary actuating mechanisms 22 and 26 may be hydraulically driven incorporating a rotary hydraulic motor or hydraulic cylinders. Alternatively the actuators may incorporate an electric motor with or without a gearbox. Whichever form of actuator is employed the actuator would normally incorporate position sensing means for determining the relative positions of the arms and the support frame.

The cutting means 18 is, as illustrated, intended to cut a plurality of lengths of preformed concrete 36 constituting work pieces. The cutting means 18 is moved by pivoting ofthe arms 19 and 20 from a start position (Fig 2) to cut in a direction at a right-angle to the lengths 36 cutting through the lengths 36 as the cutting means 18 is moved in a straight line across the frame 10. Upon completion of a cutting movement the cutting means 18 is moved back to its start position. During a cutting operation the rotary actuators 22 and 26 are operated to pivot the arms 19 and 20 to provide the desired cutting movement. It will be appreciated that by controlling the operation of the actuators 22 and 26 the cutting means 18 can execute different cutting movements including arcuate movements, a combination of arcuate and rectilinear movements and any other movement of any complex pattern within the range of the arms 19 and 20. By rotation of the arms 19 and 20 about a vertical axis angled cuts can also be made.

Instead of the use of the frame 10, as described, the arms 19 and 20 may be mounted on other base members. For example the rotary actuator 22 may be mounted on a base capable of rotary movement about a vertical axis. As another alternative the mechanism may be mounted on a vehicle so that the cutting means can effect a cutting operation on road surfaces or other surfaces on which the vehicle travels, or on surfaces above the vehicle or to the side of the vehicle.

If the range of the movement ofthe cutting means needs to be extended three or more pivotal arms may be employed, each arm being pivotally connected to the next arm through a rotary actuator.

In order to select and control the movement of the cutting means there is provided control means (not shown) for controlling the operation of the rotary actuators and of the drive for the cutting means. The control means is programmable so that any desired cutting movement may be selected and also includes feedback means whereby the pre-programmed arrangement may be altered according to operational parameters such as drive motor currents, speed of cut etc so that the movement of the arms can be altered from the pre-programmed arrangement to take account of the cutting characteristics of different work pieces, the operation of the cutting means and the kind of cutting means employed.

In the case where the cutting means is mounted on a mobile frame, as illustrated, the control means may also control the position of the frame in relation to the work pieces. The control means may also control ancillary operations such as water supply for cooling purposes to the cutting means.

The control means would incorporate sensors sensing the position, speed of operation and other relevant parameters of the components. The control means can take any convenient form suited to the operational requirements.

Claims

1. A cutting mechanism comprising at least two pivotal arms, a first arm being pivotally mounted on a base member and a second arm being pivotally mounted on the first arm, a cutting device carried on the second arm, drive means associated with the pivots between the base member and the first arm and between the first and second arms for effecting a pivoting action of the arms and to position and move the cutting device in a selected manner during a cutting movement, and control means for controlling the operation of the cutting mechanism to achieve a selected movement of the cutting device, the drive means for pivoting the arms being controlled by the control means in a preselected manner and the control means being controlled having regard to different parameters of the cutting device such as speed of cutting and drive torque.

2. A cutting mechanism according to claim 1 and comprising drive means mounted on the second arm for effecting drive of the cutting means.

3. A cutting mechanism according to claim 2 wherein the cutting means is rotary.

4. A cutting mechanism according to claim 2 wherein the cutting means is reciprocal.

5. A cutting mechanism according to any one of claims 2 to 4 wherein the drive means for the cutting means is an electric motor having a belt drive to the cutting means, the motor being mounted on the second arm.

6. A cutting mechanism according to any preceding claim wherein the base member is movable to change the position the mechanism in relation to a work piece.

7. A cutting mechanism according to claim 6 wherein the base member is a mobile frame or a tractor unit.

8. A cutting mechanism according to any preceding claim wherein the connection between the first arm and the base member includes a pivot to enable the first arm to pivot about an axis at a right-angle to the pivotal connection between the first arm and the base member.

9. A cutting mechanism according to any preceding claim wherein the control means is preprogrammable to give the desired movement of the cutting device, for example a linear movement of a preselected distance, an arcuate movement, a combination of linear and arcuate movements, or any other selected movement.

10. A cutting mechanism according to any preceding claim, including more than two pivotal arms and for each pivot drive means is provided to effect the selected movement of the cutting device.

11. A cutting mechanism substantially as described herein and with reference to the accompanying drawings.