Vacuum booster enclosure

Claim 1

A booster enclosure comprising a first, generally cylindrical shell which is open at one end and closed at the other end thereof, said first shell having a plurality of circumferentially spaced apart, radially inwardly extending claws formed on the rim of said first shell defining said open end thereof; a second shell having a peripheral edge being of a size adapted for insertion into and close fitting contact within said open end of said first shell, said second shell having a plurality of circumferentially spaced-apart grooves formed in said peripheral edge, said grooves being alignable with said claws such that said second shell can be inserted into said first shell by aligning said grooves therewith causing said claws to pass through said grooves as said second shell is inserted into said first shell so that the mutually adjacent ends are overlapped; resilient means positioned between said overlapped end portions, said resilient means being adapted to exert force on said end portions in both radial and axial directions; and interlocking means comprising mating small projection means formed on at least one of the inner periphery of said first shell at said open end thereof and said peripheral edge, and small groove means formed on the other of said inner periphery and said peripheral edge of said second shell; whereby when said second shell has been inserted into said first shell, said first and second shells can then be rotated relative to one another such that said claws are no longer in alignment with said grooves and thus extend over said peripheral edge of said second shell, said small projection means being of a small size sufficient to allow said rotation of said first and second shells past said small projection means, said rotation ceasing when said small projection means interlocks with said small groove means, such that said first and second shells are locked together by said interlocking means acting in cooperation with said claws and said resilient means.