Patent GB-1494167-A (GB)
Title: Welding
IPC: B23K15/00
Filed: 1976-06-09
Abstract: 1494167 Welding WALLACE MURRAY CORP 9 June 1976 [18 June 1975] 23784/76 Heading B3R An assembly for positioning first and second workpieces, such as a shaft 100 and turbine 102, in mutual coaxially aligned and abutting relation for the purpose of welding the workpieces together, comprises a lower base-plate 64 having a recess 82 extending therethrough for receiving the first workpiece 100, an upper baseplate 68 normally held spaced from the lower base-plate and having a recess 76 for positioning the second workpiece 102 coaxial with the first which is positioned with its upper end below the top surface of the upper base-plate, the arrangement being such that on depression ofthe upper base-plate relative to the lower, the top of the upper base-plate moves to a position below the top of the first workpiece and the second workpiece abuts the first to enable welding together by oxy-acetylene, electric, inertia or, as described, electron beam. As described, the assembly is incorporated in an electron beam welding machine having a rotatable work-table 10 carrying two work holder assemblies for successive presentation to a working position in which they are raised into a vacuum chamber 14 whereon welding together of the workpieces is effected by an electron beam gun 11, Each assembly consists of a supporting plate 40 having a seal 42 for engaging the frame 15 of the vacuum chamber 14 when the assembly is raised by a standard 28. A second standard 50 is telescopically received in standard 28 and has an upper ring 52 rotatably mounted by a bearing 54 in the plate 40. A supporting plate 60 is mounted on the ring 52 and is secured to the lower base-plate 64. The upper base-plate 68 is mounted on the lower base-plate and is urged upwardly therefrom by springs 70 to a position determined by headed pins 72 secured to the lower base-plate. A sleeve 86 is secured to the lower base-plate and is bored to receive the first workpiece 100 which may be in the form of a shaft having an enlarged end received in a countersunk portion of the bore to axially locate the shaft. The upper end of the shaft 100 is normally disposed below the upper surface of the upper base-plate 68 so that the second workpiece in the form of a turbine or impeller can be located in a recess 76 in the upper baseplate. When the assembly is in the working position, the standards 28, 50 are raised to carry the assembly into the vacuum chamber 14 with the seal 42 engaging the plate 14 and the upper base-plate engaging an abutment assembly 105 which includes a circular plate 104 carried by a portion 17 of the vacuum chamber and having depending brackets for rollers 106. The engagement of the rollers with the upper base-plate 68 moves the cutter against the pressure of the springs 70 so that its upper surface is below the upper end of the shaft 100 which abuts the impeller 102 to provide access for the welding beam. A centering pin 116 is rotatable in bearings 114 in a collar 108 mounting the plate 104 and is urged by a spring 112 into engagement with a recess in the impellers to press the turbine against the end of the shaft. During welding, the standard is rotated to rotate the lower and upper base-plates and thus the shaft and impeller.