Filters

Abstract

A filter insert ( 10 ) comprising: a body portion ( 12 ) and a closed-ended tube ( 14 ), an open end of which is sealingly affixed around the periphery of the body portion ( 12 ); an inlet aperture ( 16 ) and an outlet aperture ( 18 ) each aperture communicating via a through hole in the body portion ( 12 ) with the interior of the tube ( 14 ); a filter medium ( 20 ) located within the tube ( 14 ) and being sealingly interposed between the inlet aperture ( 16 ) and the outlet aperture ( 18 ), wherein the tube ( 14 ) is at least partially manufactured of a flexible plastics material, and wherein the body portion ( 12 ) is relatively rigid.

1 .- 40 . (canceled) 
     
     
         41 . A filter comprising a housing, a connector and a part-turn locking mechanism for releasably locking the housing to the connector, the part-turn locking mechanism comprising:
 a first position in which the housing is locked to the connector;   a second position in which the housing is retained to the connector but capable of limited axial movement relative to it; and   a third unlocked position in which the housing is unlocked from the connector.   
     
     
         42 . A filter as claimed in  claim 41 , wherein the part-turn locking mechanism comprises an engagement surface and a lug arranged to engage and slide relative to the engagement surface. 
     
     
         43 . A filter as claimed in  claim 42 , wherein the engagement surface comprises, a first flat portion, an inclined portion and a second flat portion. 
     
     
         44 . A filter as claimed in  claim 41 , wherein the part-turn locking mechanism comprises a locking collar. 
     
     
         45 . A filter as claimed in  claim 44 , wherein one of the housing, connector and locking collar comprises a lug adapted to engage with an engagement surface of another one of the housing, connector and collar, the engagement surface comprising a first flat portion and an inclined portion, wherein relative rotation of the collar and connector in a first direction causes the lug to slide over the first flat portion, thereby inhibiting axial separation of the housing and connector, and then over the inclined portion, thereby displacing the housing axially towards the connector, and wherein relative rotation of the collar and connector in a second direction opposite to the first direction causes the lug to slide over the inclined portion, thereby allowing the housing to be displaced axially away from the connector, and then over the first flat portion thereby inhibiting axial separation of the housing and connector. 
     
     
         46 . A filter as claimed in  claim 45 , further comprising an aperture in the first flat portion, the aperture being located at a radially spaced apart position from the inclined portion and being larger than the lug to allow the lug to pass therethrough thereby permitting separation of the housing from the connector when the collar is rotated by a predetermined amount in the second direction. 
     
     
         47 . A filter as claimed in  claim 45 , wherein the engagement surface comprises a second flat portion located on the opposite side of the inclined portion to the first flat portion. 
     
     
         48 . A filter as claimed in  claim 45 , comprising a plurality of lugs engageable with a plurality of engagement surfaces, each engagement surface comprising a first flat portion, an inclined portion, and optionally, a second flat portion. 
     
     
         49 . A filter as claimed in  claim 48 , wherein the lugs are unequally spaced at different radial positions. 
     
     
         50 . A filter as claimed in  claim 48 , wherein at least two of the plurality of lugs are differently shaped. 
     
     
         51 . A filter as claimed in  claim 45 , further comprising a filter insert receivable within the housing. 
     
     
         52 . A filter as claimed in  claim 51 , wherein the filter insert comprises a spigot axially engageable with a flow control valve of the connector, the flow control valve being openable upon axial displacement of the spigot towards the flow control valve and closeable upon axial displacement of the spigot away from the flow control valve. 
     
     
         53 . A filter according  claim 51 , comprising a filter insert comprising: a body portion and a closed-ended tube, an open end of which is sealingly affixed around the periphery of the body portion; an inlet aperture and an outlet aperture each aperture communicating via a through hole in the body portion with the interior of the tube; a filter medium located within the tube and being sealingly interposed between the inlet aperture and the outlet aperture, wherein the tube is at least partially manufactured of a flexible plastics material, and wherein the body portion is relatively rigid.