Anti-hijacking vehicular alarm system with timer controlled alarm circuit

Claim 2

An anti-hijacking vehicular alarm system in which an alarm is to be actuated upon unauthorized opening of a door of the vehicle, said alarm system comprising: alarm circuit means for actuating an alarm in response to the opening of a vehicle door when said means is activated; timer means capable of being actuated for a selected interval of time, said timer means being constructed such that the duration of the interval, once selected, cannot be shortened; and means responsive to actuation of said timer means for activating said alarm circuit means for the duration of said interval of time such that the alarm circuit means must remain activated for the duration of said interval.

Claim 3

The alarm system of claim 1 wherein the vehicle includes an ignition circuit, the alarm system including means responsive to actuation of said timer means for activating the ignition circuit of the vehicle for the duration of said interval of time such that the ignition circuit is activated only when the alarm circuit means is activated.

Claim 4

The alarm system of claim 2 wherein: the timer means includes a clock-timer, actuator means selectively movable manually from a rest position to a selected position and movable from said selected position to said rest position only in response to operation of said clock-timer over the duration of said timed interval, and a timing member movable with said actuator means; said means for activating the alarm circuit means includes a first electric switch in the alarm circuit means responsive to the movement of said timing member; and said means for activating the ignition circuit includes a second electric switch in the ignition circuit responsive to the movement of said timing member; said first and second electric switches rendering said alarm circuit means and said ignition circuit in activated condition while the timing member moves from the selected position toward the rest position.

Claim 5

The alarm system of claim 3 including means for selectively positively limiting the displacement of said actuator means to only a portion of the total movement available to the actuator means for selectively limiting said interval to only a portion of the full duration available for selection in the system.

Claim 6

The alarm system of claim 3 wherein: the actuator means includes a rotatable shaft; the timing member includes a timing disk rotatable with said shaft, and first camming means on the timing disk for movement along a prescribed path of travel as the timing disk rotates; the first and second electric switches each include an actuator arm lying in the path of travel of the camming means for intercepting said camming means and actuating said first and second switches to deactivate the alarm circuit means and the ignition circuit when the timing disk is at said rest position.

Claim 7

The alarm system of claim 5 wherein said camming means include projections extending from a face of the timing disk.

Claim 8

The alarm system of claim 5 including key-operated means interengaged with said rotatable shaft such that said shaft may be manually rotated only when a corresponding alarm key is received within the key-operated means, and means for retaining said alarm key within said key-operated means during the duration of said interval.

Claim 9

The alarm system of claim 5 including means for warning of the expiration of said interval just prior to such expiration, said warning means including a third electric switch; a further actuator arm for actuating said third electric switch; and second camming means on the timing disk for movement along a path of travel and located with respect to said further actuator arm such that movement of the timing disk will move said further actuator arm to actuate said third electric switch prior to actuation of said first and second electric switches; and means responsive to actuation of said third electric switch for providing said warning.

Claim 10

The alarm system of claim 8 wherein said first camming means include first projections extending from a face of the timing disk for actuating said first and second switches and said second camming means include a second projection spaced angularly from said first projections such that said further actuator arm is engaged by said second projection prior to engagement of the actuator arms associated with said first and second switches.

Claim 11

The alarm system of claim 1 including means for warning of the expiration of said interval a relatively short time prior to such expiration.