Device fitted on vehicles for monitoring tyre pressure

• US 6,194,999 B1
• Filed: 06/08/1998
• Issued: 02/27/2001
• Est. Priority Date: 05/26/1995
• Status: Expired due to Fees

• Current Assignee: Gunter Lothar Schulze, Günter Uhl, Norbert Normann, Ralph Kessler, Schröttle, Michael
• Original Assignee: Gunter Lothar Schulze, Günter Uhl, Norbert Normann, Ralph Kessler, Schröttle, Michael
• Inventors: Normann, Norbert, Uhl, Günter, Schulze, Gunter Lothar, Schröttle, Michael, Kessler, Ralph
• Primary Examiner(s): Wu, Daniel J.
• Application Number:
  US08/952,690
• Time in Patent Office: 995 Days
• Field of Search: 340/442, 340/445, 340/447, 340/448, 731/462, 731/465, 731/468, 200/61.22, 200/61.25
• US Class Current: 340/447
• CPC Class Codes: B60C 23/0433 Radio signals
• CPC Class Codes: B60C 23/0437 Means for detecting electromagnetic field changes not being part of the signal transmission per se, e.g. strength, direction, propagation or masking
• CPC Class Codes: B60C 23/0444 Antenna structures, control or arrangements thereof, e.g. for directional antennas, diversity antenna, antenna multiplexing or antennas integrated in fenders

Abstract

The proposed device is fitted on vehicles equipped with pneumatic tires and is used for monitoring tire pressure. The device comprises: a pressure measurement sensor on each of the wheels (2) being monitored; a transmitter mounted next to each pressure measurement sensor which emits signals carrying the pressure data obtained from the pressure measurement sensor, and a receiver for those signals fitted on the vehicle chassis. An antenna (5a, 6a, 7a, 8a) is arranged next to each wheel (2) as the receiver. The antennae are connected to a common receiving and monitoring circuit (15, 17).

Claims

1. Device on vehicles with wheels having air tires, for monitoring the air pressure in the tires using a pressure sensor on each of the tires (2) to be monitored, with each pressure sensor accompanied by a transmitter which sends out signals containing the sensed air pressure, and with antennas for receiving the signals which are fastened to the chassis of the vehicle, whereby merely one antenna (4;

5a-8a) is arranged in the vicinity of each wheel (2) and the antennas (4;

5a-8a) are connected with a common electronic receiving and evaluating circuitry (15, 17), characterized in that from each of the electric lines (5, 6, 7, 8) connecting the antennas with the receiving circuitry (15), a branch line (19, 20) with a rectifier (21) branches off, and the branch line connects with a microcomputer serving as an evaluating circuitry (17) which is controlled by the rectified signals in such a way that every time when a signal is received from the transmitter (3) on the wheel (2) by way of one of the antennas, the microcomputer (17) evaluates only that signal which is sent by the corresponding line (5-8) to the receiving circuitry (15).

2. Device according to claim 1, characterized in that the antenna (4;

5a-8a) utilizes an electric line (5-8) which belongs to another monitoring device assigned to the same wheel (2).

3. Device according to claim 1, characterized in that a sensor (4) belonging to another monitoring device assigned to the same wheel (2) is designed to serve as an antenna also.

4. Device according to claim 1, characterized in that an electric line which is connected to another user installed in the vicinity of a particular wheel (2), for example a rear light, is utilized as an antenna.

5. Device according to claim 2, characterized in that the other monitoring device (4) monitors the brake liner wear.

6. Device according to claim 2, characterized in that the other monitoring device (4) monitors the wheels (2) with regard to blocking (ABS system) and/or slipping (ASR system).

7. Device according to claim 1, characterized in that the electric line (5, 6, 7, 8) is a co-axial cable which is stripped of its outer conductor over a portion of its length in the vicinity of the wheel (2).

8. Device according to claim 1, characterized in that in each of the branch lines (19, 20) a limiting value switch (22) is installed which permits the rectified signal to pass through to the evaluating circuitry only if this signal exceeds a certain limiting value.

9. Device according to claim 8, characterized in that in each of the lines (5-8) connecting the antennas with the receiving circuitry an interrupting switch (22, 23) is installed which is controlled by the microcomputer (17).