| 摘要 |
1,079,465. Making cartridge cases; electromagnetic hammers. GENERAL DYNAMICS CORPORATION. May 12, 1965 [May 19, 1964], No. 20005/65. Headings B3A and B3H. [Also in Division H1 A sudden blow is imported to a workpiece by an electromagnetic hammer acting through a mass of pressure transmitting material. The invention is of particular use in dislodging tapered core pins 15, Fig. 2, from cartridge cases 11. A plurality of cases are assembled in holes 29, Fig. 1 (not shown), of a holder 27, supported on shoulders 33, and held in position by spigots 37 of a top plate 35. The detonator cavity 14 of each case is filled with a pressure transmitting fluid 39, such as silicone rubber, beeswax, paraffin, oil or water, and is closed by a piston 41 which may have sealing means. To dislodge the pins 15, the pistons 41 are struck a blow by a hammer 43 actuated by an electromagnetic coil 45 energized from a capacitor 51 through an ignitron switch 50. The capacitor is charged from a high voltage source 52 through switch 54 and resistor 53. The striking force is adjustable by spacers 61. Hammer 43 may be made of titanium with a layer of aluminium on its lower surface; radial grooves 65, Fig. 3 (not shown), may be formed in its upper face to provide lands 67 which engage the pistons 41. In another embodiment, Fig. 4 (not shown), the hammer assembly comprises a hollow core 71 wound with a helical hollow conductor 75 through which coolant is circulated. The hammer 79 rests on a conductive layer 81 separated from the core 71 by an insulator 77 of plastic impregnated fibre glass. |
