GB648173A - Method of and means for holding two generally-parallel sheet-metal strips in accurately-spaced relation, for example, in order to facilitate the welding thereof - Google Patents

Abstract

648,173. Welding ; uniting by fusion ; workholders. ROVER CO., Ltd. Dec. 10, 1948, No. 31975. [Classes 83 (iii) and 83 (iv)] (Also in Group XXII] A method of holding apart two generally-parallel sheet-metal strips 27 in spaced relation comprises supporting the strips between two lines of spaced electromagnetic means 14 having polepieces 15, 16 directed towards the strips, the pole faces of one line being accurately spaced from those of the other line, and the electromagnetic means, when energized, pulling the strips against the polepieces into the required location. In a jig for holding the two strips during welding, each line of electromagnetic means comprises coil cores 18 which interconnect the polepieces 15, 16 and are mounted in brass or other non-magnetic brackets 21 on pivoted side-members 20. A channel-section built up by welding from three strips 27, 28 is supported on a beam 32 and is mechanically held near the base by blocks 29 on the side members. When the electromagnets are energized, the sides 27 of the channel are pulled into the correct position for another strip 35 to be placed on top of them, secured there by clamps 34 on the side members and spot-welded to the sides 27. Subsequently the box-section thus formed is removed and seam-welded to form, for example, part of a motor car chassis. Alternatively, the boxsection can be made from two channel-sections by welding their flanges together, with the bases of the channel held against the polepieces in the jig.