Patent GB-571438-A (GB)
Title: Improvements in or relating to the heat treatment of metal articles
Filed: 1942-08-18
Abstract: 571,438. Heat - treating articles. SHORTER PROCESS CO., Ltd., and SHORTER, A. E. Aug. 18, 1942, No. 11575. [Class 72] In the heat treatment of metal articles, in which the heated article is quenched by a stream of liquid supplied through a hydraulic system having controllable mass-time characteristics, a predetermined mass of liquid is isolated from a source of liquid under pressure, preferably in a reservoir of variable capacity adjusted to contain a volume of liquid having the required mass and causing said mass of liquid to impinge on the heated surface. The article W is mounted on a support S in a tank T and is heated by a heater H supplied with heating medium through a conduit system C which includes a How control means 10 and a timing mechanism 11. The quenching unit Q is supplied with liquid through a system which includes a valve 12 for controlling the supply from a pump P, the valve being preferably of the solenoid type operated by closure of contacts controlled by timing mechanism 13. The system also includes an inverted V-shaped tube 14, one limb of which is connected to the valve 12 and the other to a reservoir 15 of variable capacity, a pipe 19 leading to the unit Q. Projecting upwardly from the tube 14 is a pipe 16 leading to an adjustable air inlet valve 17 having a vent pipe 18 open to the atmosphere. An adjustable air inlet valve 20 similar to the valve 17 is provided in a pipe 21 extending upwardly from the pipe 19 and liquid discharged through the pipes 18, 21 is collected in the vessels 22, 23, the latter being drained by a pipe 24 into the tank T, and from the latter by a pipe 25 into the sump D. The delivery nozzle or nozzles of the unit W must be at a level not below the reservoir 15. When the valve 17 is open, the valve 20 shut and the valve 12 open, liquid will fill the whole hydraulic system and flow out through the unit Q, a small amount escaping through the pipe 18. On turning off the valve 12, the liquid will, because of the entry of air through the valve 17, continue to flow out of the unit Q until the surface of the liquid in the reservoir 15 has fallen to the level of the unit Q, shown by the broken line B. The flow of liquid will then cease with -a column of air trapped in the tube 14 between the valve 17 and the line B. If the valve 12 is now turned on the liquid remaining in the reservoir 15 and in the pipe 19 will be initially discharged from the unit Q and there will be an interval during which the trapped column of air is ejected through the unit followed by a continuous stream of liquid. When the valve 12 is again turned off, the liquid will continue to flow until as before the liquid in the reservoir falls to the level B. The supply of heating medium is terminable by means of the timing mechanism 11 simultaneously with the energization of the solenoid operating the valve 12 which remains open for a period determined by the setting of the mechanism 13. The capacity of the reservoir 15 and the pipe 19 may be varied by adjusting the length of the pipe in which the air is trapped, preferably by using telescoping piping, one pipe extending- into another pipe of wider bore furnished with a gland provided with packing held in position by a unit as shown at G. The heating medium may be gas supplied to a burner or electrical energy operating inductively, resistively or through an arc. The parts 10, 11, 12 and 13 may be constructed to operate as described in Specification 550,404.