Patent GB-1157074-A (GB)
Title: Improvements in or relating to Self-Laying Endless Tracks and to Transporters Fitted therewith
Inventor: DOXEY BRIAN CECIL
IPC: B62D55/06
Filed: 1966-04-19
Abstract: 1,157,074. Flame cutting. BRITISH OXYGEN CO. Ltd. 23 March, 1967 [19 April, 1966], No. 17116/66. Heading B3V. [Also in Division B7] An endless track vehicle whose body 10 is quadrilateral in plan, see Division B7, comprises two pairs of endless tracks 12, 14, Fig. 1. Each track has ground engaging elements 18 which are rotatable about axes parallel to the longitudinal direction of the track. By selective actuation of the tracks, the vehicle may be moved in any direction of motion. The tracks may be driven by electric motors, manually or remotely controlled and powered by batteries carried by the vehicle or by flexible cables from a mains supply. The vehicle may carry a flame-cutting torch or may have application in transporting intense sources of gamma rays over the surface of a body to be tested; in mechanical handling; stacking, selecting or loading articles in warehouses or stores; in applying or cutting designs or patterns on carpets and in remote controlled military, aviation or agricultural operations. As applied to a device for cutting large metal plates, a torch fed by gases brought by cable or carried on the vehicle may operate through an aperture on the vehicle or may be carried by a rotatable boom 80 which may be driven through gearing by an electric motor 83 either continuously or in a series of discrete steps. The boom may be pivoted at one end or balanced by a counterweight and at its outer end may carry a lamp having a vertical filament scanned by optical telescopes 100, 102 mounted on motorized carriages 200, 202 operating on guide rails 300, 302 and which receive control instructions from a tape or plotting table. The images of the filament are scanned by photo-electric cells 500 mounted at the ends of vibrating piezo-electric rods 600. When the image is directly on the telescope axis, the relevant photo-cell produces a voltage at double the scan frequency but, off the axis, the photo-cell output contains a component of voltage at scan frequency, the phase of which changes through 180 degrees when the image changes from one side of the centre line to the other. The photo-cell output is fed into a filter 700 which removes the double frequency components and allows the fundamental component to pass through to an amplifier 800, the resulting voltage from which is fed to one of the two phase servomotors 30 driving one pair of the tracks. Alternatively, the boom 40, Fig. 3, may carry a line following head 46 and a cutting nozzle 48 to which is secured a heat shield 50. A transparent table 52, upon which a drawing is placed, is supported on the plate 54 to be cut by legs 56 and magnetic clamps 58. Signals from the line following head are transmitted to the track motors, the boom 40 being fixed relatively to the tractor. In another alternative, a cutting torch is mounted at the centre of the tractor, an optical line following head being mounted directly above the torch and follows an image projected on a ground glass screen carried by the tractor. Several tractors so equipped may be used simultaneously. Alternative control systems based on polar rather than rectilinear co-ordinates may be used and instead of telescopes, transducers responding to ultrasonic, laser, radar or other signals may be used.