Patent GB-190717308-A (GB)
Title: Improvements in Interrupters for Electric Circuits.
Inventor: WAPPLER REINHOLD HENRY
Filed: 1907-07-29
Granted: 1908-02-06
Abstract: 17,308. Wappler, R. H., and Fayer, C. F. July 29. Switches.-An electric interrupter, specially adapted for X-ray work and the like, is operated by an electromagnetic motor, rectilinear reciprocating motion being given to the vibrating contact. The operating-coil of the motor is connected in shunt with the Ruhmkorff coil, and serves to dissipate the energy of the latter when the energizing circuit is broken. A spindle d, mounted in journals c, c<1> in pillars b, b<1> secured to an insulating-base a, has flattened portions 22 which act as a cam to operate the moving contact. A fly-wheel e, of insulating-material with an armature f embedded therein, is fixed on the spindle by a screw, as shown. A solenoid a is mounted on the base a at right-angles to the spindle d so that their two central lines lie in the same horizontal plane. Another solenoid i is placed opposite to the solenoid n, but appreciably higher than the centre line of the spindle. Its core 28 has a pole-piece 29 preferably extending over one-third of the circumference of the flywheel. A switch 14 is provided for coupling either solenoid into circuit. A rod m is journaled in a cylindrical block l held by means of a circumferential groove 32 and a screw 33 in a split pillar k fastened to the base ; this rod carries the vibrating contact n, which has a stepped conical rearportion n<1> for dissipating the heat generated. A reduced end 36 of the rod m carries an insulating- plate o with a terminal plate r, to which is fastened one end of a wire 41. A rod 38, fixed in the block l and passing freely through a hole in the plate o, maintains this plate vertical ; the plate bears upon the flattened portion 22 of the spindle d by means of a spring 35 surrounding the rod m. The stationary contact w is fixed to an externally threaded rod v carried in an internally tbreaded split pillar t fixed to the base, the rod v being in line with the rod m. Stops v<2> limit the adjustment of the plate w obtainable by this arrangement, and a clamp screw 44 secures the rod when necessary. A hole 46 is drilled through the rod v and plate w for cooling the latter. The plates n, w are preferably of silver. Terminals 11, 13, 12, 25, 27 are provided for the current supply, Ruhmkorff coil, condenser, operating-magnet h, and starting-magnet i, respectively. The electric connexions are as shown in Fig. 1. The operation is as follows :-The contact stud 16 is an off-stud. To start the device, the switch arm 14 is moved momentarily on to the stud 17 ; current then flows from the terminal 11 (left-band) by way of wire 47, 48, switch-arm 14, stud 17, wire 49 through the coil i, and wires 50, 51 to the terminal (right-hand). This effects movement of the armature f from either the position indicated in Fig. 1 or that at right-angles to it, these being positions where the turning effort of the magnet h is nil. The switch arm 14 is then moved to the contact 18, and the circuit is diverted by way of the wire 52, operating-coil h, wire 53, terminal 13 (lower), rod m, contact-plates n, w, and wires 54, 51 to terminal 11 (right-hand). The Ruhmkorff coil is directly in shunt with coil h, and rupture of the energizing-current of both coils by rotation of the fly-wheel e results in the energizing of the coil h, which is of high resistance, from the self-induction of the Ruhmkorff coil, thereby increasing the speed of the interrupter. The condenser is connected across the make-and-break switch by means of the terminals 12.