Anti-theft vehicle brake-supervising device

Claim 1

An anti-theft vehicle brake-supervising device of the type which selectively prevents reverse flow of a fluid from at least one vehicle wheel cylinder back to the vehicle master cylinder to thereby maintain the braking function of said fluid within said wheel cylinder, the improvement comprising wall means defining a cylindrical flow chamber of a prescribed diameter having opposite distal and proximal ends, a first fluid connection connected from said flow chamber distal end to said vehicle master cylinder, a second fluid connection connected from said flow chamber proximal end to said vehicle wheel cylinder, said first and second fluid connections cooperating to normally allow opposite direction fluid flow between said master cylinder and wheel cylinder through said flow chamber, a bypass passageway connected between said distal end of said flow chamber and said second fluid connection having a one-way valve operatively disposed therein effective to permit fluid flow only from said master cylinder into said wheel cylinder incident to utilizing said fluid to selectively immobilize said vehicle, and a cylindrically shaped flow control member having a medial portion of a prescribed smaller radius size than said cylindrical flow chamber and having enlarged diameter portions with sealing means thereon at opposite ends extending into sealing contact with said flow chamber wall to thereby define an external flow passage of a prescribed longitudinal length and in encircling relation about said cylindrical flow control member bounded at opposite ends by said sealing means, said cylindrical flow control member being operatively arranged to be manually urged through movement in said flow chamber between an operative position adjacent said proximal end thereof in which said external flow passage is in communication only with said wheel cylinder fluid connection and an operative position adjacent said flow chamber distal end in which the longitudinal length of said external flow passage extends also to said master cylinder fluid connection to thereby provide communication between said wheel cylinder and said master cylinder through said external flow passage incident to the release of said fluid immobilizing said vehicle, whereby the manual urging of said cylindrical flow control member from said proximal end to said distal end of said flow chamber to cause the release of said vehicle is aided by the pressure and flow direction of said fluid returning to said master cylinder.