GB1459103A - Guiding a working head - Google Patents

Abstract

1459103 Welding by fusion MITSUBISHI JUKOGYO KK 7 Jan 1974 [8 Jan 1973 2 Feb 1973] 00595/74 Heading B3R In moving a working head (e.g. for inspecting, surface finishing, cleaning or, as shown, welding) along fillet lines a, b and b, c between intersecting walls and a base of a structure, such as the lattice structure shown in Fig. 1A, in order that the head may operate into and out of the corner b between said lines it is both rotated about a fixed point adjacent said corner and moved radially of said point. In Figs. 4, 5, a truck 1, supported on a structure base 5 by a driving wheel 2 and a freely rotatable castor 3, has a sucker 7 which when actuated to stick to said base provides a pivot 0 about which the truck can rotate. A structure-wall-following plate 9 having wallengaging rollers 10 is supported on the truck for free rotation about the pivot 0 and is lockable to said truck by means not shown. A welding torch 12 is horizontally slidable in said truck in a cylinder the axis of which intersects the pivot 0. The torch is fast with a cam follower 13 engaging a cam groove 14 in the plate 9. A compression spring 15 is provided between the follower 13 and the end of the cylinder 11. In operation, with the plate 9 locked to the truck with the torch normal to the structure wall, and two rollers 10 of said plate engaging said wall, the truck is driven along said wall and fillet welding is effected. When a corner is reached the leading pair of rollers 10 engages the next wall, the sucker 7 is actuated and the plate 9 unlocked, whereupon the truck and torch rotate about the pivot 0 by 90 degrees. During this rotation the cam follower 13 moves in the cam groove 14 to effect radially outward and then inward corner welding movement of the torch. On completion of said 90 degrees rotation, the sucker 7 is de-actuated and the plate 9 locked to the truck, and the truck is driven along said next wall. The position of the intersection of the axis of the tip of the welding torch and the structure may be changed by changing the mounting position of the follower 13 on the torch. In Figs. 8-10 (not shown) the cam follower 13 is inwardly spring-pressed against the peripheral edge of a cam plate geared so as to be rotationally fixed with the structure-wall-following plate 9. For structures other than rectangular plan, e.g. parallelogram plan, the wall engaging rollers are arranged on the plate 9 accordingly. In a further method (Figs. 2, 3, not shown), the tip of the welding torch is angled, in the horizontal plane, at 5 degrees to its line of radial movement. The torch tip is downwardly angled at 45 degrees and is of the CO 2 solid wire type. The torch may be followed by a second torch angularly disposed thereto about the same pivot point.