Distance warning device for vehicles

Claim 2

A distance warning installation for vehicles, especially for motor vehicles, characterized in that each vehicle is equipped with two transmitter means mounted substantially at roof height to the left and right of the vehicle for transmitting radiant energy toward the rear and with a forwardly directed receiver means disposed at the front end of the vehicle for receiving the same type of radiant energy, said transmitter means radiating each a directional beam rearwardly with predetermined inclination both with respect to the plane of the road surface as well as with respect to the vehicle longitudinal center plane and thus an area of increased radiation intensity results at a predetermined distance to the rear of the vehicle which can be detected by a receiver means of a following vehicle, and in that upon impingement of the increased radiation intensity area of the directional beams transmitted by the transmitter means of a preceding vehicle on the receiver means of a following vehicle, a control signal is automatically produced by said receiver means.

Claim 3

An installation according to claim 1, characterized in that said control signal produces an acoustic warning signal.

Claim 4

An installation according to claim 1, characterized in that said control signal produces an optic signal.

Claim 5

An installation according to claim 1, with vehicle braking means, characterized in that said control signal automatically initiates a braking operation by said braking means.

Claim 6

An installation according to claim 1, characterized in that each transmitter means is so constructed that the inclination of the directional beam to the road surface is variable in dependence on the vehicle velocity so that the receiver means of a following vehicle can detect the directional beam of the preceding vehicle travelling at lower velocity at a larger distance than at a higher velocity of the preceding vehicle.

Claim 7

An installation according to claim 5, characterized in that the vehicle receiver means is so constructed that it responds to a predetermined intensity of the received directional beam.

Claim 8

An installation according to claim 5, characterized in that the vehicle receiver means is so constructed that it responds to a predetermined change of intensity dI/dt corresponding to the relative oncoming velocity of the following vehicle into the radiation space of a preceding vehicle.

Claim 9

An installation according to claim 5, characterized in that each transmitter means is so constructed that for purposes of avoiding interference radiation, it transmits a directional beam with characteristic signal and that the receiver means is so constructed that it responds only to directional beams with these characteristic signals.

Claim 10

An installation according to claim 6, characterized in that each transmitter means is so constructed that it transmits a directional beam with a frequency dependent on the vehicle velocity and that the receiver means is so constructed that it compares the frequency of a received directional beam with a frequency proportional to the velocity of its own vehicle and upon determination of predetermined comparison criteria produces said control signal.

Claim 11

An installation according to claim 9, characterized in that the receiver means of each vehicle is provided with shielding means which is so constructed that only the directional beams of a vehicle travelling in the same lane can impinge on the receiver means.

Claim 12

An installation according to claim 8, characterized in that the directional beam has a constant frequency as characteristic signal.

Claim 13

An installation according to claim 8, characterized in that the directional beam has a constant pulse repetition rate as characteristic signal.

Claim 14

An installation according to claim 8, characterized in that the vehicle receiver means is so constructed that it responds to a predetermined intensity of the received directional beam.

Claim 15

An installation according to claim 8, characterized in that the vehicle receiver means is so constructed that it responds to a predetermined change of intensity dI/dt corresponding to the relative oncoming velocity of the following vehicle into the radiation space of a preceding vehicle.

Claim 16

A distance warning installation for vehicles, especially for motor vehicles, characterized in that each vehicle is equipped with at least one transmitter means for transmitting a radiant energy directional beam toward the rear and with a forwardly directed receiver means disposed at the front end of the vehicle for receiving the same type of radiant energy, in that upon impingement of the directional beam transmitted by the transmitter means of a preceding vehicle on the receiver means of a following vehicle, a control signal is automatically produced by said receiver means, and in that each transmitter means is so constructed that the inclination of the directional beam to the road surface is variable in dependence on the vehicle velocity so that the receiver means of a following vehicle can detect at a larger distance the directional beam of the preceding vehicle travelling at lower velocity than a preceding vehicle travelling at a higher velocity.

Claim 17

A distance warning installation for vehicles, especially for motor vehicles, characterized in that each vehicle is equipped with at least one transmitter means for transmitting a radiant energy directional beam toward the rear and with a forwardly directed receiver means disposed at the front end of the vehicle for receiving the same type of radiant energy, in that upon impingement of the directional beam transmitted by the transmitter means of a preceding vehicle on the receiver means of a following vehicle, a control signal is automatically produced by said receiver means, and in that each transmitter means is so constructed that the inclination of the directional beam to the road surface is variable in dependence on the vehicle velocity so that the receiver means of a following vehicle can detect at a larger distance the directional beam of the preceding vehicle travelling at lower velocity than a preceding vehicle travelling at a higher velocity.

Claim 18

A distance warning installation for vehicles, especially for motor vehicles, characterized in that each vehicle is equipped with at least one transmitter means for transmitting radiant energy toward the rear and with a forwardly directed receiver means disposed at the front end of the vehicle for receiving the same type of radiant energy, in that upon impingement of the directional beam transmitted by the transmitter means of a preceding vehicle on the receiver means oF a following vehicle, a control signal is automatically produced by said receiver means, and in that the vehicle receiver means is so constructed that it responds to a predetermined change of intensity dI/dt corresponding to the relative oncoming velocity of the following vehicle into the radiation space of a preceding vehicle.

Claim 19

A distance warning installation for vehicles, especially for motor vehicles, characterized in that each vehicle is equipped with at least one transmitter means for transmitting radiant energy toward the rear and with a forwardly directed receiver means disposed at the front end of the vehicle for receiving the same type of radiant energy, in that upon impingement of the directional beam transmitted by the transmitter means of a preceding vehicle on the receiver means oF a following vehicle, a control signal is automatically produced by said receiver means, and in that the vehicle receiver means is so constructed that it responds to a predetermined change of intensity dI/dt corresponding to the relative oncoming velocity of the following vehicle into the radiation space of a preceding vehicle.

Claim 20

A distance warning installation for vehicles, especially for motor vehicles, characterized in that each vehicle is equipped with at least one transmitter means for transmitting a radiant energy directional beam toward the rear and with a forwardly directed receiver means disposed at the front end of the vehicle for receiving the same type of radiant energy, in that upon impingement of the directional beam transmitted by the transmitter means of a preceding vehicle on the receiver means of a following vehicle, a control signal is automatically produced by said receiver means, in that each transmitter means is so constructed that it transmits a directional beam with a frequency dependent on the vehicle velocity and that the receiver means is so constructed that it compares the frequency of a received directional beam with a frequency proportional to the velocity of its own vehicle and upon determination of predetermined comparison criteria produces said control signal, each vehicle being equipped with two transmitter means mounted substantially at roof height to the left and right of the vehicle, said transmitter means radiating each a directional beam rearwardly with predetermined inclination both with respect to the plane of the road surface as well as with respect to the vehicle longitudinal center plane and thus an area of increased radiation intensity results at a predetermined distance to the rear of the vehicle which can be detected by a receiver means of a following vehicle.

Claim 21

A distance warning installation for vehicles, especially for motor vehicles, characterized in that each vehicle is equipped with at least one transmitter means for transmitting a radiant energy directional beam toward the rear and with a forwardly directed receiver means disposed at the front end of the vehicle for receiving the same type of radiant energy, in that upon impingement of the directional beam transmitted by the transmitter means of a preceding vehicle on the receiver means of a following vehicle, a control signal is automatically produced by said receiver means, in that each transmitter means is so constructed that it transmits a directional beam with a frequency dependent on the vehicle velocity and that the receiver means is so constructed that it compares the frequency of a received directional beam with a frequency proportional to the velocity of its own vehicle and upon determination of predetermined comparison criteria produces said control signal, each vehicle being equipped with two transmitter means mounted substantially at roof height to the left and right of the vehicle, said transmitter means radiating each a directional beam rearwardly with predetermined inclination both with respect to the plane of the road surface as well as with respect to the vehicle longitudinal center plane and thus an area of increased radiation intensity results at a predetermined distance to the rear of the vehicle which can be detected by a receiver means of a following vehicle.