GB956817A - Filters for liquids - Google Patents

Abstract

956,817. Filters. GENERAL MOTORS Ltd. Feb. 28, 1963 [March 14, 1962], No. 9740/62. Heading B 1 D. In a liquid filter, an end-cap at one end of a filter element forms one part of a housing for a pressure relief valve, the other part of the valve housing being resiliently pressed into sealing contact with said end-cap. An oil-filter, Fig. 1, comprises a metal casing 1 formed with flange 2 seated on gasket 3 in recess 4 in a mount face 5. The casing has coaxial bolt or stud 6 having enlarged end 7 brazed or welded to the base of casing 1, the other end of stud 6 extending beyond the end of the casing and screwed into opening 9 in mount face 5. Annular filter element 10 of pleated, resinimpregnated paper is mounted on perforate tube 11, on stud 6 and is provided with endcaps 12. A cup-shaped metal pressing 19 forming a valve housing member is mounted on stud 6, and is provided with a coaxial series of valve ports 20, formed between coaxial beads 21, and with a flange 22. Compression spring 23 abuts against the base of casing 1 and presses the rim 22 of the housing 1a against annular bead 14 on end-cap 12. This spring also presses the other end-cap against mount-faces with opposite sides of element 10 in communication with oil inlet and outlet 17 and 18. The centrally recessed portion of end-cap 12 forms with member 19 a valve housing within which is an annular valve disc 24 slidably mounted on stud 6 and pressed against beads 21 by one end of helical spring 25 the other end of which abuts end-cap 12. Bosses 26 are formed on stud 6 to prevent accidental removal of springs 23 and 25, housing member 19 and valve disc 24 from the stud. The central opening of each end-cap 12 has radial recesses 27, Fig. 2, so that the end-caps will clear the bosses 26 when the element is fitted over stud 6. Recesses 27 may constitute the valve outlet and the filtered oil outlet. Additional openings 28 may be formed in the end-caps. In the filter of Fig. 1 the element 10 is reversible so that either end-cap may form part of the valve housing. The endcap forming part of the housing may also be flat; the member 19 may be flat or cup-shaped. When filter element 10 becomes clogged, the oil pressure increases until valve disc member 24 becomes unseated to permit by-pass flow of liquid via valve ports 20 and recesses 27 in each of the end caps 12 to the outlet opening 18.