Patent GB-547931-A (GB)
Title: Improvements in or relating to apparatus for the heat treatment of internal metal surfaces
IPC: C21D9/14
Filed: 1941-06-04
Abstract: 547,931. Heat-treating metals; burners. SHORTER PROCESS CO., Ltd., and SHORTER, A. E. June 4, 1941, No. 7050. [Class 72] [Also in Group XI] An apparatus for heat - treating an internal metal surface e.g. of a bearing member, comprises a burner head which is located in juxtaposition with respect to the surface to provide a combustion zone between the burner and the surface and is provided with longitudinal gas passages provided with radial outlets, and with means such as longitudinal flutes in the burner head or a plurality of channels in the head terminating in orifices interspersed between the gas outlets, for leading an auxiliary supply of a combustionsupporting medium such as air, to the combustion zone. The heating device may be formed integrally with a quenching unit supplied with fluid through - a conduit extending through the burner head. The burner head 10, Fig. 4, having radial gas outlets 16 is provided with a central conduit 12 which conveys quenching fluid to the quenching unit 11 provided with radial outlets 23. The head 10 is secured to a gas-distributing chamber 13 having air inlet 14 connected to a supply of gaseous fuel, e.g. an oxy-acetylene mixture, and communicating with a plurality of gas passages 15 in the head, each passage tapering towards the bottom. A combustion supporting gas such as. air is fed into a pipe 17 which extends down through the chamber 13 and divides into two tubes 18 which lead to channels 19, Fig. 2, having a series of radial outlets 20. Alternatively, the tubes 18, and channels 19 are omitted and the external surface of the burner head is provided with longitudinal flutes between the gas outlets 16. The burner head 10 is located as shown in the central bore 26, which is to be hardened, of a bearing member 25 mounted in the jaws 27 of a chuck which is rotated round the central axis of the bore. During the heating operation, fluid supplied to the conduit 12 passes through the burner head 10 and when the bore 26 has been heated sufficiently the apparatus is moved to withdraw the head 10 and move the unit 11 into the bore to quench the heated surface. To locate the apparatus in the bore, a guide member 28 is provided with a central aperture to receive a guide pin 29 projecting from a plug 22 acting as a closure member for the quenching chamber 21. To control, automatically, the heat-treating operation, the burner 10 and quenching unit 11 are supported in a clamp 30, Fig. 5, secured to a bracket 31 projecting from a carriage 32 mounted in a vertical slide 33, secured to a stanchion 34 on a base plate 35. The carriage 32 is connected to a counterweight 36 by a belt 37 passing over pulleys 38, 39, its upward movement being limited by a stop 40. The burner 10 is held in position within the bore 26 of the article 25 by the engagement with an aperture 42 in the carriage 32 of a spring- controlled detent 41 adapted to be engaged by a cam 44 forming a projection at one end of a lever 45 pivoted on the stanchion 34 and pivotally connected at its upper end through a link 46 to the movable core 47 of a solenoid 48. The gases are fed to the burner by pipes 46, 47 leading to a pressure regulating and proportioning valve mechanism 48 connected to a push button mechanism 49 for switching the gas supply on and off, from which a pipe 50 leads the gases to the inlet 14. A gas timing mechanism 51 for determining the period of the heating, and a quench timing mechanism 52 for determining the quenching period, and a master switch 57. are mounted on the stanchion 34. The article 26 is supported on a plate 56 which is secured to a turntable 53 coupled through reduction gear 54 to a driving motor 55. The central aperture 56 on the plate 53 is provided with a series of fins 58 which engage the outside of the unit 11 from which the fluid passing through the outlets 23 drains away through ports 59 and ports 60 in the turntable 53, the latter with its associated parts being mounted in a tank 61. Where the bore to be treated is formed by a drilling, reaming or like operation, performed, e.g. on a lathe, the heat treating device may be an additional tool in the turret of the lathe.