Hydraulic tractor theft prevention device

An anti-theft device for use with vehicles having brakes that are normally applied to prevent vehicle movement and that are hydraulically released for use when the vehicle is started, the vehicle including a hydraulic fluid reservoir for containing hydraulic fluid and a hydraulic fluid pump for delivering hydraulic fluid under pressure to a brake release actuator from which the hydraulic fluid recirculates to the reservoir, said anti-theft device comprising:

• a substantially rectangular block-shaped body having opposed first and second faces, opposed top and bottom sides, and opposed ends;
• a substantially cylindrical bore extending from said top side of said body to a terminal end of said bore within said body;
• a first internal passageway formed in said body with said first internal passageway communicating with said cylindrical bore and extending therefrom to a terminal end within said body;
• a second internal passageway formed in said body with said second internal passageway communicating with said cylindrical bore and extending therefrom to a terminal end within said body, said terminal end of said second internal passageway being displaced from said terminal end of said first passageway;
• a substantially cylindrical valve core having a longitudinal axis, an external end and an internal end and being positioned within said substantially cylindrical bore, wherein said external end is located at said top side of said body and said internal end is positioned within said bore spaced from said terminal end thereof;
• said first and second internal passageways communicating with said bore at a position intermediate said external and internal ends of said valve core;
• sealing means for sealing said valve core against an interior surface of said bore adjacent said external and internal ends thereof;
• a conduit formed in said valve core with said conduit having a first end communicating with said terminal end of said bore and a second end communicating with said bore at a position corresponding to a location where said first and second internal passageways communicate with said bore;
• said valve core being rotatable about said longitudinal axis within said bore between a first position wherein said second end of said conduit communicates with said first internal passageway and a second position wherein said second end of said conduit communicates with said second internal passageway;
• an elongated handle having a first end and a second end, wherein said first handle end is fastened to said exterior end of said valve core, said handle having a secure position, wherein said handle extends from said valve core exterior end, along said top side of said block, such that when said valve core is in said valve core first position, a longitudinal axis of said handle is aligned with a longitudinal axis of said block, and wherein exterior edges of said handle are disposed inwardly of edges of said top surface;
• a locking mechanism disposed near said second handle end for locking said handle means in said secure position;
• a fluid inlet port coupled to and communicating with said bore at the terminal end thereof for receiving hydraulic fluid under pressure from the hydraulic pump;
• a first fluid outlet port coupled to and communicating with said first internal passageway adjacent the terminal end thereof for delivering hydraulic fluid back to the hydraulic fluid reservoir;
• and
• a second fluid outlet port coupled to and communicating with said terminal end of said second internal passageway for delivering hydraulic fluid to the brake release actuator,
• whereby when said handle is locked in place in said secure position, hydraulic fluid is directed from the hydraulic pump through said valve core, said first internal passageway and back to the reservoir leaving the brakes engaged so that the vehicle can not be operated and when said handle is unlocked and rotated from said secure position, hydraulic fluid is directed from the hydraulic pump through said valve core, said second internal passageway and to the brake release actuator to release the brakes for operation of the vehicle.