GB735936A - Improvements in or relating to pressure-proof housings - Google Patents

Abstract

735,936. Closures for resisting fluid pressure. SIEMENS-SCHUCKERTWERKE AKT.-GES. May 30, 1952 [Oct. 17, 1951], No. 13858/52. Class 123(1). [Also in Group XXXVII] The pressure proof casing of apparatus such as electrical equipment to be used in mines or other places where there is danger of explosion, comprises a housing part and a cover, both having walls thick enough to withstand the pressure of an explosion, both having flanges normally abutting to form an airtight seal, but held in such a way that internal pressure can cause separation of the flanges, labyrinthine means in the joint preventing particles from passing out of the casing. This means may comprise a bar 6 in slots 5 in the flanges. A tongue 22 and the groove 23 in which it fits may be formed in separate pieces fixed to the housing parts, Fig. 6. The pieces may be held by pressure, screws or locating pins, and may extend around the whole or part of the periphery of the casing, overlapping edges being arranged in other parts. Abutting ends or crossing over parts of bars 6 may be joined by inter-engaging recesses and projections arranged to maintain the labyrinthine effect. Fig. 8 shows a casing 31 with a cover 29 hinged at 30 and sealed with a bar screwed to the cover along the edges parallel to the paper, and by overlap along the other edges 32, 33. A bar and slot seal may be provided at the hinged edge. Where a slot cuts an overlapping edge the bar 40 which fits it may carry a suitably shaped extension 41.