Patent GB-550404-A (GB)
Abstract: 550,404. Heat treating metals. SHORTER PROCESS CO., Ltd., and SHORTER, A. E. July 14, 1941, No. 8870. [Class 72] [Also in Groups XXIX and XXXVII] A portable or transportable control unit for a heat treating apparatus includes time controls for independently controlling the flow of at least two heat treating media and means for permitting these media' to flow independently of the time controls. The Figures show a form of the invention suitable for controlling the supplies of fuel gas, such as acetylene, of combustion supporting gas, such as oxygen and of quenching media usually air or water to a surface hardening apparatus. The control unit comprises a casing H housing three valves F, O, W, controlling the fuel, oxygen and water respectively. The valves F, O are actuated by a common solenoid and the valve W by a solenoid WS, both solenoids being under the control of a relay system RS itself controlled by timing devices GT, WT and push-button switches TGS, TWS, CS, and LS. The relay comprises a pair of contacts RG1, RG2, adapted to be closed by a solenoid RSG to energize the solenoid GS and a pair of contacts RW1, RW2 adapted to be closed by a soleniod to energize the soleniod WS. When the push TGS is depressed the solenoids RSG and GS are energized to open the fuel valves for testing purposes. Similarly, depression of the push TWS opens the quenching valve. When the push CS is momentarily depressed a solenoid GTR is energized to couple the hand 15 to the armature of the motor GTM which coupling closes contacts GTB. This in turn energizes the solenoid GS to open the valves F, O. When the hand 15 reaches a' preselector hand 13 the contacts GTB are opened to cut out the solenoid RSG and thus break the circuit including the solenoid GS. At the same time a cam device driven by the motor armature uncouples the hand 15 and allows it to return under spring action to its initial position. As the hand is uncoupled, contacts GTA are momentarily closed energizing solenoid WTR which initiates a similar series of operations associated with the motor WTM. The cycle may be interrupted at any time by opening the switch LS. A delay may be introduced between the closing of valves F, O, and the opening of the valve W by arranging cam devices driven by the motor armature so that a suitable interval elapses between the opening of the contacts GTB and the closing of the contacts GTA. Double contact sockets GA, GB, GS, WA, WB, and WC may be arranged in parallel with the solenoids GS, WS for connection to electrical apparatus for effecting at appropriate times relative movement between the article being treated and the heating and quenching units. If electrical energy is used in place of a flame, it may be applied either inductively resistively or through an electric arc. According to the Provisional Specification clockwork may be used in place of the synchronous motors and the timing mechanism by itself may be used to control solenoid-actuated valves housed in the heattreating apparatus. If a plurality of similar articles are to be treated, they may be mounted in a conveyer belt having a tripping mechanism coupled to the master switch arranged so that when the heat-treating cycle is completed the master switch is turned off and the treated article moved out of range of the heating and quenching devices. Subsequent movement of the conveyer brings the succeeding article within range and recloses the master switch and the cycle is repeated.