Richard J Mackinnon

US Patent:

41079620, Aug 22, 1978

Filed:

Apr 28, 1977

Appl. No.:

5/791856

Inventors:

Richard B. MacKinnon - Waltham MA

International Classification:

B60R 2504

US Classification:

70243

Abstract:

A circuit for controlling the operability of an electrically-operated fuel system, for a vehicle, and particularly for controlling a fuel injection system. The circuitry includes a timing network and a concealed switch the position of which is only known to an authorized operator of the vehicle. When the concealed switch is closed by an authorized person an associated relay is energized and the timing network is inhibited which in turn maintains a main control relay in its enabling position permitting normal operation of the fuel system. In this authorized mode of operation the timing network is essentially maintained in a state where it is not permitted to time-out. When an unauthorized person gains entry to the vehicle, by-passing the ignition switch, the concealed switch is not closed, nor is the associated relay energized. The timing network is thus permitted to time-out and after a presettable period the main control relay is switched to its disabling position interrupting operation of the fuel system and, of course, the vehicle after the unauthorized person has traveled only a relatively short distance thinking he has safely taken the vehicle.