GB770965A - Improvements in or relating to closures of pressure vessels - Google Patents

Abstract

770,965. Pressure cookers and like vessels. DIENY, A. Oct. 25, 1954 [Oct. 23, 1953; Oct. 30, 1953 ; Dec. 31, 1953], No. 30631/54. Class 123 (1). A pressure vessel, such as a cooker 1, Figs. 1 and 2 having an inwardly-turned upper rim 20, is closed by a lid 2 which has a cylindrical peripheral part 2b terminating in an outwardlyturned rim 2f of slightly smaller diameter than the inner diameter of the rim 20, and steamtightness between the cooker and lid is secured by an elastic sealing ring 12 which, after insertion of the lid into the cooker, is located on the rim 2f to encircle the lid part 2b and to be compressed between the rims 2f, 20 by the built-up internal pressure. Preferably the cooker rim 20 is cut away at, say, three spaced points 20a, the lid rim 2f being provided with three corresponding extensions 2h adapted, initially, to contact an inner shoulder 1a towards the upper end of the cooker to centre the lid, and the spaces 20a permitting parts of the sealing ring 12 to be bent upwardly, Fig. 4, by internal over-pressure to release the latter. The sealing ring 12, which may be of circular or elliptical cross-section and, if desired, reinforced by a helical spring core, is formed with an outwardly-projecting hand grip 12a to facilitate its removal from the lid after the cooking operation. The lid may be provided with a pressurerelease valve, fusible safety plug, &c. Opposed handles 28, Fig. 7, on the cooker are secured to one another and to the cooker by a pair of rods 30 which engage an outer groove in the cooker wall, corresponding to the internal shoulder la, and have their ends connected to the handles by screws 31.