Position-sensitive alarm system
First Claim
1. A vehicle alarm system adapted for installation in a vehicle havinga warning device (41, 42) triggerable upon detection of a disturbance to the vehicle andcomprisingat least one position sensitive sensor (10, 10'"'"') furnishing repetitively, continuously sequentially position output signals representative of the position of the vehicle on a support surface;
- data storage means (30,
51) connected to and receiving the position output signals from said sensor, and storing data representative of the position of the vehicle on the support surface;
comparator means (34,
53) connected to said data storage means and said position sensitive sensor and receiving stored data indicative of a prior position of the vehicle as represented by a prior position output signal as well as a then furnished position output signal, and comparing said prior and then furnished signals for detecting a deviation of the position output signal furnished by said sensor (10) from a stored value retained in the storage means,said comparator means furnishing a triggering signal to said warning device (41,
42) when said deviation of position exceeds a predetermined amount to provide a warning when a disturbance of the position of the vehicle with respect to a prior position on said support surface is sensed by said sensor.
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Accused Products
Abstract
To increase the responsiveness of a vehicle alarm system to, for example, unauthorized entry through windows, jacking up for removal of parts or vehicle theft as well violent impact by another vehicle, at least one position sensitive sensor has its output signal, which represents the instantaneous position of the vehicle stored after activation of the alarm system. Any change in that position is detected and triggers a warning device when the deviation exceeds a predeterminable amount. The position sensitive sensor may be a fluid-filled vessel the internal resistance of which is measured in a resistance bridge or it may be a variable inductance sensor which is connected to a frequency generator whose output signals are counted and compared with a given value. The system according to the invention may also serve as an accelerometer.
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Citations
18 Claims
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1. A vehicle alarm system adapted for installation in a vehicle having
a warning device (41, 42) triggerable upon detection of a disturbance to the vehicle and comprising at least one position sensitive sensor (10, 10'"'"') furnishing repetitively, continuously sequentially position output signals representative of the position of the vehicle on a support surface; -
data storage means (30,
51) connected to and receiving the position output signals from said sensor, and storing data representative of the position of the vehicle on the support surface;comparator means (34,
53) connected to said data storage means and said position sensitive sensor and receiving stored data indicative of a prior position of the vehicle as represented by a prior position output signal as well as a then furnished position output signal, and comparing said prior and then furnished signals for detecting a deviation of the position output signal furnished by said sensor (10) from a stored value retained in the storage means,said comparator means furnishing a triggering signal to said warning device (41,
42) when said deviation of position exceeds a predetermined amount to provide a warning when a disturbance of the position of the vehicle with respect to a prior position on said support surface is sensed by said sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification