| 摘要 |
637,032. Electric welding. CYC-ARC, Ltd., and AINSWORTH, A. R. Nov. 24, 1947, Nos. 31058/47 and 5203/48. [Class 83 (iv)] In a portable arc stud-welder the studholder 25 is carried by a crosshead 21 from a piston 17 movable in a cylinder 3 and operated by a ram 44 through a liquid confined between the piston 17 and the ram 44. The holder 25 automatically adjusts the volume of confined liquid to suit the stud by drawing from or rejecting to a reservoir 5 through a port 35 shut on the first movement of the ram 44. The ram 44 is operated against a spring 46 by an electromagnetic solenoid core &c. 45 to raise the holder 25 against a spring 56 for arcing. The speed of lift is controlled by a throttle valve 63 preset for stud diameter, material, &c. The reservoir 5 has a variable volume portion 48 comprising a bellows and the liquid is totally enclosed. In a modification, Fig. 4 (not shown), the variable volume portion comprises a cylinder with a sprung piston. In a further modification, Fig. 7, the ram 185, piston 168 and bellows reservoir 175 are co-axial, the piston 168 remains stationary, and the stud holder 198 is carried by a cylinder 170 movable about the piston 168. The speed of lift during operation is controlled by presetting the spring 192 against which the solenoid core 184 operates. In a similar modification, Fig. 5 (not shown), the cylinder is stationary, the piston is movable and carries the stud holder on a crosshead and the reservoir comprises an annular chamber with a spring piston. In a further static form, Fig. 9, for use on a drill press or like machine having a vertically reciprocable tool carrier, solenoid core 203 drives the ram 206 through a pivoted lever, the piston 205 is parallel to the stud holder 213 and the fluid passages and reservoir 219 are combined in a single unit 204. In a final modification, Fig. 6 (not shown), the fluid passages are provided in a unit immersed in a fluid tank. |
