Anti-theft device for motorized vehicles

• US 5,061,915 A
• Filed: 06/12/1990
• Issued: 10/29/1991
• Est. Priority Date: 05/22/1990
• Status: Expired due to Fees

• Current Assignee: Del A. Murphy
• Original Assignee: Del A. Murphy
• Inventors: Murphy, Del A.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US07/536,709
• Time in Patent Office: 504 Days
• Field of Search: 340/426, 340/430, 340/527, 340/528, 340/543, 307/9.1, 307/10.1, 307/10.2, 307/10.3, 307/10.4, 307/10.6
• US Class Current: 340/426.12
• CPC Class Codes: B60R 25/04 operating on the propulsion system, e.g. engine or drive motor
• CPC Class Codes: B60R 25/1003 Alarm systems characterised by arm or disarm features
• CPC Class Codes: B60R 25/23 using manual input of alphanumerical codes

Abstract

An anti-theft device for motorized vehicles consisting of three relays and a number of switches controlled by the relays that are wired into the existing electrical system of the vehicle. The first relay energizes in response to an electrical signal generated by the existing electrical system and controls the sequencing of the disarming steps. The second relay disarms the device when energized by a signal generated in the existing electrical system but only after the first relay has been energized. The third relay activates the alarm and/or disables the vehicle starter when energized. The third relay will energize when there is an attempt to start a vehicle without following the prescribed sequence of disarming steps and is prevented from sounding an alarm and/or disabling the vehicle starter by the second relay when the second relay is energized. A connector consisting of a male-female pair that is installed with the pair disconnected. The connector allows the vehicle operator to disarm the system from inside the vehicle once the alarm is triggered. The operator can thereby practice the sequence of disarming steps until he is comfortable with the invention, whereupon he can simply connect the male-female pair to prevent disarming of the device from inside the vehicle once the device is triggered. The valet switch switches power from the electrical system directly to the third relay to energize the third relay and activate the device unless the valet switch is used while the device has already been disarmed or disabled.

Claims

1. An anti-theft device for a motorized vehicle with an electrical system having a common ground and a starter;

comprising;

a first relay that energizes in response to an electrical signal from the electrical system;

a first switch having a first and a second pole that switches power from the electrical system between the first and the second pole of said first switch;

a second relay that energizes only when said first switch switches power from the first pole of said first switch to the second pole of said first switch after said first relay is energized;

a second switch having a first and a second pole that switches power from the electrical system to the first pole of said second switch until said second relay is energized, whereupon said second switch switches power to the second pole of said second switch;

a third relay that energizes when power from the electrical system is switched by said second switch to the second pole of said second switch while said third relay is connected to the common ground;

a third switch connecting said third relay to the common ground that disconnects said third relay from the common ground when said second relay is energized; and

a fourth switch having a first pole electrically connected to the starter and a second pole, said fourth switch switching power from the second pole of said second switch to the starter unless said third relay is energized.

2. The anti-theft device of claim 1, further comprising a fifth switch that switches power from the electrical system to an alarm when said third relay is energized.

3. The anti-theft device of claim 2 wherein said fifth switch also switches power to said third relay once said third relay is energized.

8. The anti-theft apparatus of claims 1, 4, or 7 further comprising a removable reset connector short circuiting said third switch.

9. The anti-theft apparatus of claims 1, 4, or 7 further comprising:

a first valet switch that transmits power from the electrical system when closed; and

a second valet switches that switches power received from said first valet switch between said first switch and said third relay.

4. An anti-theft device for a motorized vehicle with an alarm and an electrical system having a common ground, comprising:

a first relay that energizes in response to an electrical signal from the electrical system;

a first switch having a first and a second pole that switches power from the electrical system between the first and the second pole of said first switch;

a second relay that energizes only when said first switch switches power from the first pole of said first switch to the second pole of said first switch after said first relay is energized;

a second switch having a first and a second pole that switches power from the electrical system to the first pole of said second switch until said second relay is energized, whereupon said second switch switches power to the second pole of said switch;

a third relay that energizes when power from the electrical system is switched by said second switch to the second pole of said second switch while said third relay is connected to the common ground;

a third switch connecting said third relay to the common ground that disconnects said third relay from the common ground when said second relay is energized; and

a fourth switch that switches power from the electrical system to the alarm when said third relay is energized.

5. The anti-theft device of claim 4 wherein said fourth switch also switches power to said third relay once said third relay is energized.

6. The anti-theft apparatus of claim 4 or claim 5 further comprising a fifth switch having a first pole electrically connected to the starter of the motorized vehicle and a second pole, said fifth switch switching power from the second pole of said second switch to the starter unless said third relay is energized.

7. An anti-theft apparatus for a motorized vehicle with an electrical system having a common ground, a starter, and an alarm, comprising:

a first relay that energizes in response to an electrical signal from the electrical system;

a first switch having a first and a second pole that switches power from the electrical system between the first and the second pole of said first switch;

a second relay that energizes only when said first switch switches power from the first pole of said first switch to the second pole of said first switch after said first relay is energized;

a second switch having a first and a second pole that switches power from the electrical system to the first pole of said second switch until said second relay is energized, whereupon said second switch switches power to the second pole of said switch;

a third relay that energizes when power from the electrical system is switched by said second switch to the second pole of said second switch while said third relay is connected to the common ground;

a third switch connecting said third relay to the common ground that disconnects said third relay from common ground when said second relay is energized;

a fourth switch that switches power from the electrical system to the alarm when said third relay is energized; and

a fifth switch having a first pole electrically connected to the starter and said third relay and a second pole, said fourth switch switching power from the second pole of said second switch to the starter and to said third relay unless said third relay is energized.