Rolling diaphragm apparatus
AssigneeAutomotive Products plc
InventorsJohn P. Burke, Alastair J. Young
Life of this patent
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Abstract
This invention relates to a rolling diaphragm apparatus in which an annular diaphragm is secured by its outer and inner peripheries respectively to a housing and a piston between which the diaphragm seals against fluid leakage. One of said peripheries is formed as a bead which locates in an annular seat on the part to which said one periphery is attached, the bead being retained on its seat by a resilient retaining ring that snaps into position on the seat part. The bead has a substantially radially directed face and a substantially axially directed face, both of said faces engaging with corresponding faces on the retaining ring which snaps into positive engagement with the seat part. Such a construction is particularly useful in vacuum boosters for motor vehicle braking systems.
Claims4
A rolling diaphragm apparatus having:
- a housing;
- a piston;
- an annular diaphragm secured by its inner and outer peripheries respectively to said piston and housing;
- a bead formed on the diaphragm at one of said inner and outer peripheries and having thereon a substantially axially directed face and a substantially radially directed face;
- an annular seat formed on the respective one of said piston and housing to which the bead is attached and into which the bead locates;
- and a resilient retaining ring having a positive snap fit engagement with the respective seat part, said snap fit being formed by a detent on one of the ring and seat part engaging a groove in the other of the ring and seat part and the ring having corresponding faces thereon that engage with said bead faces, said ring having a portion that constitutes an annular axial projection that engages the seat part into which the ring snaps to support the ring against movement caused by loads acting on said diaphragm, said portion constituting a piston back stop means that prevents the piston from contacting the housing on retraction from an operative stroke.
Dependencies are inferred from the claim text.