Valved filter support tube

Claim 2

In a liquid filter unit having an annular filter element within a cup-shaped casing closed by an end plate with a central outlet opening and inlet openings therearound respectively in communication with the inside and the outside of the filter element: a support tube having an apertured end portion which extends axially beyond one end of the element, an opposite end portions portion which fits within one end of, and extends partially within, said element, and a radial flange which is in sealing contact with said one end of the element; a combined seal and relief valve member formed of elastomeric material and comprising an annular disc which abuts the inner surface of said end plate and has a resiliently flexible outer peripheral flange portion which normally overlies said inlet openings and is in sealing contact with the inner surface of the end plate therearound, an inner peripheral portion which is in sealing contact with said end plate around said outlet opening, and, intermediate said peripheral portions, a coaxial tubular neck which is in resilient sealing contact with an internal annular portion of said support tube adjacent said apertured end portion; an end cap which is held in sealing contact with the other end of said element and is resiliently biased so as to press the apertured end of the support tube into engagement with said disc around said neck; and said peripheral flange being resiliently deflectable under the pressure of liquid entering said inlet openings to permit liquid to pass into the casing for passage through the filter element, and said neck being resiliently deflectable at a predetermined pressure by liquid which passes from said inlet openings into contact with said neck by way of the openings in said apertured end portion of the support tube, to permit liquid entering the casing to bypass the filter element and flow direct to said outlet opening.

Claim 3

In a liquid filter unit having an annular filter element within a cup-shaped casing closed by an end plate with a central outlet opening and inlet openings therearound respectively in communication with the inside and the outside of the filter element, said element being formed of pleated sheet filter material with the ends of each pleat individually sealed separately from adjacent pleats: a plastics support tube having a grooved outer surface, a castellated end portion which extends axially beyond one end of the element, an opposite end portion which fits within one end of, and extends partially within, said element, and, a radial flange which is in sealing contact with said one end of the element over at least the inner peripheral portion thereof; a combined seal and relief valve member formed of elastomeric material and comprising an annular disc which abuts the inner surface of said end plate and has a resiliently flexible outer peripheral flange portion which normally overlies said inlet openings and is in sealing contact with the inner surface of the end plate therearound, an inner peripheral portion which is in sealing contact with said end plate around said outlet opening, and, intermediate said peripheral portions a coaxial tubular neck which is in resilient sealing contact with an internal annular portion of said support tube adjacent said apertured end portion; an end cap which is held in sealing contact with the other end of said element and is resiliently biased so as to press the castellated end of the support tube inTo engagement with said disc around said neck; and said peripheral flange being resiliently deflectable under the pressure of liquid entering said inlet openings to permit liquid to pass into the casing for passage through the filter elements, and said neck being resiliently deflectable at a predetermined pressure by liquid which passes from said inlet openings into contact with said neck by way of the openings in said castellated end portion of the support tube, to permit liquid entering the casing to bypass the filter element and flow direct to said outlet opening.

Claim 4

In a liquid filter unit having an annular filter element within a cup-shaped casing closed by an end plate with a central outlet opening and inlet openings therearound respectively in communication with the inside and the outside of the filter element, said element being formed of pleated sheet filter material with the ends of each pleat individually sealed separately from adjacent pleats: a plastics support tube having a grooved outer surface, a castellated end portion which extends axially beyond one end of the element, an opposite end portion which fits within one end of, and extends partially within, said element, and, a radial flange which is in sealing contact with said one end of the element over at least the inner peripheral portion thereof; a combined seal and relief valve member formed of elastomeric material and comprising an annular disc which abuts the inner surface of said end plate and has a resiliently flexible outer peripheral flange portion which normally overlies said inlet openings and is in sealing contact with the inner surface of the end plate therearound, an inner peripheral portion which is in sealing contact with said end plate around said outlet opening, and, intermediate said peripheral portions a coaxial tubular neck which is in resilient sealing contact with an internal annular portion of said support tube adjacent said apertured end portion; an end cap which is held in sealing contact with the other end of said element and is resiliently biased so as to press the castellated end of the support tube inTo engagement with said disc around said neck; and said peripheral flange being resiliently deflectable under the pressure of liquid entering said inlet openings to permit liquid to pass into the casing for passage through the filter elements, and said neck being resiliently deflectable at a predetermined pressure by liquid which passes from said inlet openings into contact with said neck by way of the openings in said castellated end portion of the support tube, to permit liquid entering the casing to bypass the filter element and flow direct to said outlet opening.

Claim 5

In a liquid filter unit having an annular filter element within a cup-shaped casing closed by an end plate with a central outlet opening and inlet openings therearound respectively in communication with the inside and the outside of the filter element, said element being made of pleated sheet filter material with the ends of each pleat individually sealed separately from adjacent pleats: a plastics support tube having a groove external surface, an apertured end portion which extends axially beyond one end of the element, a radial flange which is in sealing contact with said one end of the element over at least the inner peripheral portion thereof, and an opposite end portion which fits within one end of, and extends partially within, said element, and which terminates in a perforate end wall; a combined seal and relief valve member formed of elastomeric material and comprising an annular disc which abuts the inner surface of said end plate and has a resiliently flexible outer peripheral flange portion which normally overlies said inlet openings and is in sealing contact with the inner surface of the end plate therearound, an inner peripheral portion which is in sealing contact with said end plate around said outlet opening, and, intermediate said peripheral portions a coaxial tubular neck which is in resilient sealing contact with an internal annular portion of said support tube adjacent said apertured end portion; an end cap which is held in sealing contact with the other end of said element by interengaged formations on said end wall and end cap, said end cap having integral resilient members which engage the base of said casing to press the apertured end of the support tube into engagement with said disc around said neck; and said peripheral flange being resiliently deflectable under the pressure of liquid entering said inlet openings to permit liquid to pass into the casing for passage through the filter element and said neck being resiliently deflectable at a predetermined pressure by liquid which passes from said inlet openings into contact with said neck by way of the openings in said apertured end portion of the support tube so as to permit liquid entering the casing to bypass the filter element and flow direct to said outlet opening.

Claim 6

In a liquid filter unit having an annular filter element within a cup-shaped casing closed by an end plate with a central outlet opening and inlet openings therearound respectively in communication with the inside and the outside of the filter element, said element being made of pleated sheet filter material with the ends of each pleat individually sealed separately from adjacent pleats: a plastics support tube having a groove external surface, an apertured end portion which extends axially beyond one end of the element, a radial flange which is in sealing contact with said one end of the element over at least the inner peripheral portion thereof, and an opposite end portion which fits within one end of, and extends partially within, said element, and which terminates in a perforate end wall; a combined seal and relief valve member formed of elastomeric material and comprising an annular disc which abuts the inner surface of said end plate and has a resiliently flexible outer peripheral flange portion which normally overlies said inlet openings and is in sealing contact with the inner surface of the end plate therearound, an inner peripheral portion which is in sealing contact with said end plate around said outlet opening, and, intermediate said peripheral portions a coaxial tubular neck which is in resilient sealing contact with an internal annular portion of said support tube adjacent said apertured end portion; an end cap which is held in sealing contact with the other end of said element by interengaged formations on said end wall and end cap, said end cap having integral resilient members which engage the base of said casing to press the apertured end of the support tube into engagement with said disc around said neck; and said peripheral flange being resiliently deflectable under the pressure of liquid entering said inlet openings to permit liquid to pass into the casing for passage through the filter element and said neck being resiliently deflectable at a predetermined pressure by liquid which passes from said inlet openings into contact with said neck by way of the openings in said apertured end portion of the support tube so as to permit liquid entering the casing to bypass the filter element and flow direct to said outlet opening.

Claim 7

A filter unit according to claim 2, in which the outer surface of said support tube has intersecting longitudinal and circumferential grooves therein to facilitate the flow of filtered liquid from said element into the interior of said support tube.

Claim 8

A filter unit according to claim 1, in which one end of a helical spring abuts a seat in the base of said cup-shaped casing and the other end of said spring abuts said end cap to press said end cap into sealing engagement with said element and press said support tube into engagement with said seal and relief valve member.

Claim 9

A filter unit according to claim 1, in which said radial flange on said support tube and said end plate each have an integral peripheral skirt which respectively fit around peripheral portions of said element at opposite ends thereof.

Claim 10

A filter unit according to claim 3, in which said radial flange on the support tube has projections thereon to prevent the peripheral flange on said seal member from forming a seal with said radial flange when said peripheral flange is deflected.