Vehicle collision prevention device

Claim 1

A vehicle collision prevention device intended to be mounted in a vehicle in a position having a clear line of vision forwardly of the vehicle to detect the presence of a vehicle in front of the protected vehicle and behind which the protected vehicle is to travel, the device comprising a hollow box-like housing including a front surface and a bottom surface, a radar transmitting and receiving antenna mounted in said housing immediately behind said front surface and adapted to transmit electromagnetic radar waves in a direction forwardly of the vehicle and to receive any such waves which strike the forward vehicle and are bounced rearwardly therefrom, a radar unit connected to said antenna and providing an electrical voltage output signal proportional to the distance between said forward vehicle and said protected vehicle, a distance control manually settable by the vehicle driver to a desired distance at which the vehicle driver wishes to follow the front vehicle, the preset distance control providing an output voltage signal indicative of the preset distance selected by the vehicle driver, a distance integrator circuit receiving said radar unit output signal and said preset distance control output signal in a manner to compare the same and provide a proportional comparative output voltage signal, a difference integrator circuit, said comparactive output signal from said distance integrator being fed into said difference integrator circuit, an electrical generator tachometer adapted to be connected to a speedometer cable of said protected vehicle for generating an electrical voltage indicative of the speed of the vehicle at all times, said tachometer generator signal being fed into said difference integrator circuit, means for applying the braking system of the protected vehicle, and said difference integrator providing output signals proportional to the difference between the tachometer generator signal and the distance integrator comparative output signal to operate said means in a manner to selectively apply and release the brake system of the vehicle whereby said vehicle may be slowed to automatically follow the forward vehicle at the selected preset distance.