GB697816A - Improvements relating to liquid filters having a by-pass valve - Google Patents

Abstract

697,816. Filters. SIMMONDS AEROCESSORIES, Ltd. March 19, 1952 [April 10, 1951], No. 8331/51. Class 46 [Also in Group XXIX] In a liquid filter having an excess-pres-- sure by-pass valve the valve comprises an annular body of rubber or the like having an annular cantilver portion which normally covers one or more apertures through which the liquid may flow to by-pass the filter element and which flexes to uncover one or more apertures when excessivepressure develops across the element, the body being mounted in a housing fixed in the filter casing and supporting the element. Such a valve body 6, is a snug fit in a housing 7, Fig. 1, and has an annular cantilever portion 19 covering holes 10. The housing interior communicates with the region surrounding the filter outlet tube 4 by the spaces between inturned fingers 20 provided at the end of a tubular shank 15 and urged against a circlip 21 by a spring 22. The spring 22 is retained in contact with the housing 7 for ease of assembly by lugs 17 on the end of a tubular extension 16 which fits snugly about the tube 4. In Fig. 2, the valve body 6 embraces the tube 4 and is secured to the 'housing 7 by an annular portion 24 of the latter. The spring 22 bears against a separate annular disc member 25 seating against the outer end of the valve body 6. In the construction of Fig. 1, the valve body may be spring-loaded by a spring interposed between the valve body and the base of the retainer member 11; the cantilever portion 19 may be relatively thin, the valve being arranged to open at a desired operating pressure by the use of a spring of suitable strength. In the embodiments shown the operating pressure is a function both of the material of the valve body 6 and of the shape of the cantilever portion 19 and may be varied as desired.