GB259719A - Improvements relating to electro-magnetically operated mechanism - Google Patents

Abstract

259,719. Electrical Apparatus Co., Ltd., Aerozon Air Conditioning Co., Ltd., and Walton, J. R. Aug. 26, 1925. Sparking-preventing devices.-In order to prevent excessive sparking at the control switch of electromagnetically-operated valves &c. an auxiliary electromagnet is provided in series with the main electromagnet the circuit of which is broken at contacts controlled by the auxiliary electromagnet when its winding is short-circuited by contacts on the control switch. As shown in Fig. 1 the electromagnet k has an armature f controlling a valve b through a spring-retracted rod g. The electromagnet k is connected as shown in Fig. 3 in series with an auxiliary electromagnet n when the contact arm v of the control switch engages the fixed contact w. As soon as the electromagnet n is thus energized the movable contact arm q controlled thereby engages the fixed contact r and completes a maintaining circuit for electromagnets n and k independently of the control switch. When the control switch arm is moved across to engage the contact x the coil n is short-circuited and the release of contact q breaks the circuit of electromagnet k at contacts q, r which are designed to take the arcing, contact q being pivotally spring mounted on the pivoted armature p and contact r being in the form of a roller. The two electromagnets are mounted together on a suitable framework, a portion of the member y forming a common magnetic circuit for both electromagnets.