GB257327A - Improvements in or connected with electro-therapeutic apparatus - Google Patents

Abstract

257,327. Parry, P., and Brayne, D. H. May 25, 1925. Electric appliances.-In an electortherapeutic apparatus of the type in which the patient is electrically insulated from the earth and is periodically connected therewith, the make and break device comprises an electromagnet or solenoid, the armature of which makes and breaks the supply circuit of the magnet as well as the patient's earth circuit. Fig. 2 shows the underside of a panel carrying the circuit-breaking apparatus. The swinging pivoted armature c of the electromagnet a has a contact spring k in the magnet circuit and a contact arm p in the patient's circuit. A stud h has insulated and conducting sides, and in one direction of movement of the armature the spring k makes connection with the conducting side to energize the magnet, but when the armature moves in the opposite direction, the spring rubs against the insulated side. The circuit of the magnet is completed by means of switch which connects together the terminals l, n, but to ensure starting when the contact spring is not on the conducting side of the stud h, an auxiliary contact l<1> is provided, whereby the contact-breaker can be shortcircuited. A resistance r, s is included in the patient's circuit. In a modification of the make and break device, Fig. 9, a point h<1> bears against a conducting disc coaxial with the armature pivots. The disc is free to turn relatively to the armature to an extent determined by a driving pin y which engages with opposite sides of a recess z cut in the disc. To break the magnet circuit at the end of the armature swing, a piece of insulating material x<1> is let into the disc flush with the surface.