Patent GB-557767-A (GB)
Title: Novel or improved guiding means, or former, for guiding an arc or other welding tool, flame cutter, machine cutter or other tool in relation to the work
IPC: B23K5/08
Filed: 1942-08-22
Abstract: 557,767. Guiding lining brushes. AUSTIN MOTOR CO., Ltd., BLUNDELL, J. P., and ELT, R. O. Aug. 22, 1942, No. 11842. [Class 95] [Also in Group XXII] Uniting or dividing by fusion; milling; copying- mechanism. A guide means or former for guiding an arc or other welding tool, flame cutter or melting or other cutting tool or lining brush in relation to a work piece comprises a chain or perforated band driven by a toothed wheel and passing over a set of chain or other wheels or over the edge of a shaped former, the diameter of the wheels or radii of the curved parts of the former being such and the wheels or former so positioned that a given point on the chain or band will follow a track which corresponds to or is the reciprocal of the track which it is desired that the tool shall follow in relation to the work. The speed of the tool in relation to the work is thus kept constant. The tool or work may be traversed. If the work is traversed and the tool stationary the track of a given point on the chain or band when it connects to the work is the reciprocal of the required form of the track of the tool in relation to the the work. The path of the point may be continuous or may be reciprocating in cases where the track extends only over a part of the work. Chain or other wheels may be removably mounted on spindles or studs screwed to a plate on which the work is mounted so as to vary the form of track. In welding two pressed halves of a petrol tank 12, the rear half to which the front is previously tack-welded, is secured by pairs of clamps 23. 24, 25, in a frame 14a, provided with links 28 connected at the other ends to two opposite corners of a square frame 30 the other corners of which are connected by links 32 to arms 33 rigidly secured on a rotatable disc 11 so that the frame may be moved in any direction over the surface or the disc without changing its orientation in relation thereto. The frame is anchored by a pin 15 to an endless chain 16 which is traversed in a slot 89 between the two parts of the disc which are secured through distance pieces to a disc 87. Fig. 5 carried by a sleeve 79 mounted in ball bearings 78 on a central shaft 40. The disc 11 carries chain wheels 17, 17a round which the chain is traversed, the wheel 17a being driven through chains 36, 39 from the shaft 40 which is driven .through a chain 42 from a gear box 43 driven by an electric motor 44. During welding of straight parts of the work the disc 11 is stationary, but is partially rotated when operating on curved parts 80 as to keep the tool normal to the seam. The arc welding electrode 13 is mounted on a bracket 18 hinged at 19 to the forms 10 and provided with adjusting screws 20, 21. The arc is placed slightly below the centre of the disc so as to compensate for the variation in speed.due to the variation in the direction of rotation of the disc relative to the traverse of the chain. In order to rotate the disc intermittently a fixed square plate 22 is provided mounting a set of cams 54-57 and rods 58-61 which in turn engage a roller 91 on an arm 90 keyed to the sleeve 79 so as to rotate it in an anti-clockwise direction. The sleeve is connected by a friction clutch 81, 83 and chain gear 85, 86 to the gear box 43 so as normally to tend to rotate it in a clockwise direction against the action of the rods 58-61. The rods which are guided by rollers 74 are connected by links 62- 65 to spring controlled pivoted arms 66-69 carry, ingrollers 70-73 engaging their respective cams. The cams are mounted on studs 53 carrying chain wheels 51 which are driven by a chain 50 from a shaft 49 connected by a chain 47 to the shaft 40. The push rod 59 is controlled laterally by a spring 75 so that it can be pushed out of the  way when it fouls the push rod 58.