GB2063134A

GB2063134A - Apparatus for linearly moving a tool

Info

Publication number: GB2063134A
Application number: GB7938729A
Authority: GB
Original assignee: FERROUS TRANSFORMERS Ltd
Current assignee: FERROUS TRANSFORMERS Ltd
Priority date: 1979-11-08
Filing date: 1979-11-08
Publication date: 1981-06-03
Also published as: GB2063134B

Abstract

An apparatus for linearly moving a tool 2, e.g. an electric welding torch cutting tool or spray, comprises a linearly movable carriage 1 to which the tool 2 is secured, a rail 3 along which the carriage 1 is linearly movable, and slider means 4 secured to the carriage 1 for sliding movement relative to the rail 3. A drive cable 5 (e.g. of wire, chain or rope) secured to the carriage 2 forms a closed loop having runs which extend along the rail 3 such that the carriage may be driven to and fro along the rail. Control means including spaced actuating members 28 along the rail 3 are provided for selectively actuating or deactuating the operation of the tool 2 secured in use to the carriage 1, via a switch 29 carried below the carriage. Actuating members 26 may be provided at or adjacent each end of the rail for actuating a limit switch 27 to reverse the direction of movement of the carriage 1. Ultrasonic, arc and plasma welding means are referred to. <IMAGE>

Description

SPECIFICATION Apparatus for linearly moving a tool This invention relates to an apparatus for linearly moving a tool, e.g. an electric welding torch, comprising a linearly movable carriage to which the tool is secured in use and a track along which the carriage is linearly movable. In one such apparatus the carriage is provided with a pinion which moves to and fro along a rack by means of a motor carried by the carriage. If the rack is of a fixed length it would be necessary to replace this by a rack of greater length if the carriage were required to travel a distance greater than the length of the first rack.

According to the invention there is provided an apparatus for linearly moving a tool comprising a linearly movable carriage to which the tool is secured in use, a rail along which the carriage is linearly movable, slider means secured to the carriage for sliding movement relative to the rail, and a cable secured to the carriage and forming a closed loop having runs which extend along the rail such that the carriage may be driven to an fro along the rail.

Lengths of rail, which are comparatively inexpensive to manufacture, may be connected together to provide the desired length. By using a cable drive it is no longer necessary to mount a motor on the carriage.

Suitably the carriage is provided with a tool holder assembly comprising a mast transversely movable relative to the carriage, a slider which is slidably mounted on the mast and an arm which is pivotably movable relative to the slider.

Actuating members may be provided one at or adjacent each end of the rail for actuating a limit switch mounted on the carriage to reverse the direction of movement of the carriage at the end of its movement in one direction.

Further actuating members may be provided at spaced intervals along the rails for actuating a further switch secured to the carriage to actuate or deactuate the operation of the tool secured in use to the carriage.

The position of the actuating means and the limit switch and/or that of the further actuating means and the further limit switch may be reversed, if desired. In practice it is simpler to provide the limit switches on the carriage especially where a large number of actuating means are required.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a side view of an apparatus for moving a tool, showing a cable drive for a carriage to which the tool is to be secured, the carriage being movable along a rail; and Figure 2 is a perspective view of the apparatus from the side remote from that shown in Figure 1, showing the tool secured to the carriage and sliders secured to the carriage for sliding relative to the rail.

Referring to the drawings, the apparatus shown comprises a linearly movable carriage 1 to which the tool 2 to be moved is secured. in this embodiment, the tool 2 is an electric welding tool or torch connected to a stationary electrical power source (not shown) by means of a power supply cable 40.

The apparatus further includes a rail 3, which is of I-cross section in this embodiment, along which the carriage 2 is movable and slider means in the form of four slider members 4 each located at a respective corner of the carriage. As shown in Figure 1, a drive cable 5 is secured to the carriage 2 by supports 6,7 each of which hold one end of the cable 5. The cable 5 extends in a direction parallel to the rail 3 from the support 7, passes over a pulley Sat one end of the rail 3, extends back parallel to the direction of the rail 3 passing through apertures (not shown) in the supports 6,7, passes over an idler pulley (not shown) at the far end (not shown) of the rail 3 and returns parallel to the direction of the rail 3 to the support 6.By the application of drive to the pulleys the carriage 2 may be driven to and fro along the rail according to the rotational direction of the pulley 8.

The pulley 8 is driven by a variable speed, reversible electric motor 9 through suitable gearing 10. Tensioning rollers 11 are provided as shown for maintaining tension in the cable 5.

The carriage 1 is also provided with a tool holder assembly 12 comprising a mast 13 transversely movable relative to the carriage 1, a slider 14 slidably mounted on the mast 13 and an arm 15 pivotably movable relative to the slider 14. A tool-holding sleeve assembly 16 is secured to the arm 15. Clamps 17, 18 are respectively provided for holding the slider 14 at a fixed position relative to the mast 13 and for holding the arm 15 fixed relative to the slider 14. The mast 13 is held in a base 16 which is movable along a track 19 which extends transversely to the direction of movement of the carriage 2 by means such as a wormwheel (not shown) connected to a handwheel 20. The base 16 may be locked in a desired position by screws 41. The tool 2 is also supported by means of an auxiliary tool holder assembly 21 which clamps the cable 40.In this embodiment, the assembly comprises a mast 22 fixed relative to the carriage 1 and an arm 23 pivotably mounted on a slider 24 provided with a clamp 25. The cable 40 is clamped by a cable clamp (not shown) to the arm 23.

Actuating members are provided one at each end of the rail 3, one of which members 26 is shown in Figure 2, for actuating a limit switch 27 to reverse the direction of movement of the carriage 1 at the end of its movement in one direction. Further actuating members 28 are provided at spaced intervals along the rail 3 for actuating a further switch 29 to actuate or deactuate the operation of the tool 2. The switches 26 and 29 form part of switching circuitry (not shown) enclosed in a housing 30 secured to the carriage 1.

The controls for the carriage are shown in Figure 2.

These comprise a motor speed selector 31, a direction of, travel switch 32 having a centre "offposition", a start button 33, a weld sequence button 34, a warning light 35 for indicating a "welding on" mode and a "weld off" safety switch 36.

With the start button 33 depressed and a suitable speed selected by the selector 31, the carriage 1 will travel to and fro along the rail 3. Its initial direction is determined by the setting of the switch 32. As long as the safety switch 36 is in the "off" position, no current is supplied to the welding tool. To initiate the supply of current, the switch 36 is moved to the "on" position and the weld sequence button 34 is depressed. The tool 2 will then perform welding operatins at positions determined by the actuating members 28. The tool 2 can be arranged to weld continuously instead of at spaced intervals if the switching circuitry controlled by actuating members 28 is deactuated or the actuating members 28 removed. Manual override of the actuating members 26 can be achieved by manually switching of the switch 32 as and when desired.

Fillet, butt and lap welds may be performed with the aid of the apparatus described with reference to the drawings. The rail may be caused to extend horizontally or vertically as desired. Using a suitable jig, several small components can be placed in line and the welding tool will pass each in turn. Alternatively, the welding of only two components may be performed, such as the welding of two elongate strips to provide a composite strip of T-shaped cross section for example.

It will be appreciated that if it is desired to extend the length of the rail 3, then this may be accom plished by the joining of a further length of rail of the same cross-section with the aid of fishplates for example.

The drive cable 5 is preferably in the form of a wire but may be a chain or rope. It is not necessary for the runs of the cable to extend parallel to the direction of the rail, but they would normally lie in substantially the same plane.

Although the apparatus has been described with reference to the drawings in connection with a welding tool, it will be appreciated that any suitable tool may be used with the apparatus, e.g. a cutting tool or a plant spraying head. Furthermore, the welding tool may be an ultrasonic welding tool, arc welding electrode or plasma torch for example.

Claims

1. An apparatus for moving a tool comprising a movable carriage to which the tool is secured in use, a rail along which the carriage is movable, slider means secured to the carriage for sliding movement relative to the rail, a cable secured to the carriage and forming a closed loop having runs which extend along the rail such that the carriage may be driven to and fro along the rail, and control means for selectively actuating or deactuating the operation of the tool secured in use to the carriage.

2. An apparatus as claimed in Claim 1, wherein actuating members are provided one at or adjacent each end of the rail for actuating a limit switch mounted on the carriage to reverse the direction of movement of the carriage at the end of its move ment in one direction.

3. An apparatus as claimed in Claim 2, wherein said control means comprises further actuating members provided at spaced intervals along the rails for actuating a further limit switch secured to the carriage.

4. An apparatus as claimed in any preceding Claim, wherein the drive cable is secured to the carriage by supports each of which holds one end of the cable.

5. An apparatus as claimed in Claim 4, wherein the cable extends in a direction parallel to the rail from one support, passes over a drive pulley at one end of the rail, extends back parallel to the rail passing through apertures in the supports, passes over an idler pulley at the other end of the rail and returns parallel to the direction of the rail to the other support.

6. An apparatus as claimed in Claim 5, wherein the drive pulley is driven by a variable speed, reversible electric motor.

7. An apparatus as claimed in any preceding Claim, comprising tensioning roller for maintaining tension in the cable.

8. An apparatus as claimed in any preceding Claim, wherein the carriage is provided with a tool holder assembly comprising a mast transversely movable relative to the carriage, a slider which is slidably mounted on the mast and an arm which is pivotably movable relative to the slider.

9. An apparatus as claimed in Claim 8, comprising clamps for holding the slider at a fixed position relative to the mast and for holding the arm fixed relative to the slider.

10. An apparatus as claimed in Claim 8 or Claim 9, wherein the mast is held in a base which is movable along a track which extends transversely to the direction of movement of the carriage.

11. An apparatus as claimed in Claim 8, Claim 9 or Claim 10, comprising a further said tool holder located adjacent said tool holder whereby the tool in use may be supported by both tool holders.

12. An apparatus as claimed in any preceding Claim, wherein the cable is in the form of a wire, chain or rope.

13. An apparatus for moving a tool, substantially as hereinbefore described with reference to the accompanying drawings.