Arrangement of a magnetic coupling coil and a transponder circuit on a vehicle wheel

• US 20060049928A1
• Filed: 08/31/2005
• Published: 03/09/2006
• Est. Priority Date: 09/03/2004
• Status: Active Grant

• Current Assignee: SMARTRAC TECHNOLOGY GERMANY GmbH (Avery Dennison Corporation)
• Original Assignee: SMARTRAC TECHNOLOGY GERMANY GmbH (Avery Dennison Corporation)
• Inventors: Ening, Christian
• Granted Patent: US 7,375,626 B2
• Time in Patent Office: Days
• US Class Current: 340/448
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: H01Q 1/2241 used in or for vehicle tyres
• CPC Class Codes: H01Q 1/3291 mounted in or on other locations inside the vehicle or vehicle body
• CPC Class Codes: H01Q 7/06 with core of ferromagnetic material H01Q7/02 takes precedence
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/45 Transponders
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

The arrangement of a magnetic coupling coil (2) and a transponder circuit (1) on a vehicle wheel (5) allows wireless data communication with an interrogation circuit (3) arranged on a fixed structure of the vehicle on which the wheel is mounted so as to be able to rotate about at least one rotational axis (9). The magnetic coupling coil is mounted coaxially to the rotational axis of the wheel and defines a closed loop. This coupling coil acts as an inductive coupling interface between an antenna coil (10) of the transponder and an excitation coil (4) of the interrogation circuit. This magnetic coupling coil comprises a loop portion (2″) oriented such that the magnetic field (11′) in the magnetic coupling coil, which is induced by a primary magnetic field (8) generated by the interrogation circuit excitation coil, is directed in this loop portion in a substantially perpendicular direction to the primary magnetic field. The antenna coil (10) of the transponder circuit, which is arranged in a winding (2″) of the coupling coil loop portion, is oriented so that only the magnetic field induced in the coupling coil loop portion passes therethrough without being influenced by the primary magnetic field.

Claims

1. An arrangement of a magnetic coupling coil and a transponder circuit on a vehicle wheel for wireless communication with an interrogation circuit arranged on a fixed structure of the vehicle on which the wheel is mounted so as to be able to rotate about at least one rotational axis, the magnetic coupling coil, which is coaxially mounted to the rotational axis of the wheel and defines a closed loop, acting as an inductive coupling interface between an antenna coil of the transponder circuit and an excitation coil of the interrogation circuit, wherein the magnetic coupling coil comprises a loop portion oriented such that the magnetic field in the magnetic coupling coil, which is induced by a primary magnetic field generated by the excitation coil of the interrogation circuit, is directed in this loop portion in a substantially perpendicular direction to the primary magnetic field, and wherein the antenna coil of the transponder circuit, which is arranged on the coupling coil loop portion, is oriented such that only the induced magnetic field of the coupling coil loop portion passes therethrough without being influenced by the primary magnetic field.

2. The arrangement according to claim 1, wherein the coupling coil portion describes a winding formed of at least one turn inside which there is arranged the transponder circuit antenna coil, the winding axis parallel to the axis of the turns of the antenna coil being substantially perpendicular to the rotational axis of the wheel.

3. The arrangement according to claim 2, wherein the loop portion winding comprises several turns extending over a distance corresponding to the length of the antenna coil of the transponder circuit in the direction of the axis of the turns.

4. The arrangement according to claim 1, wherein the coupling coil is arranged at the periphery of the wheel on or in an inner lateral wall of the tyre of the vehicle wheel, the excitation coil of the interrogation circuit is arranged on a part of the body or chassis of said vehicle opposite the periphery of the wheel, characterized wherein the transponder of the transponder circuit is of the passive type to be supplied with energy by the primary magnetic field transmitted by the excitation coil of the interrogation circuit.

5. The arrangement according to claim 4, wherein at least the coupling coil loop portion is not integrated in the inner lateral wall of the tyre, and wherein the transponder circuit is held by bonding or using hooks on the inner lateral wall of the tyre, the antenna coil being arranged in a winding of the loop portion.

6. The arrangement according to claim 4, wherein the transponder circuit includes a pressure measurement sensor and/or a temperature measurement sensor encapsulated in a plastic or glass case.

7. The arrangement according to claims 1, wherein the loop of the magnetic coupling coil, which describes at least two turns, is arranged on or in two inner lateral walls of the tyre of the vehicle wheel.