Monitoring apparatus for wheel units of an automobile

• US 6,446,764 B1
• Filed: 03/19/2002
• Issued: 09/10/2002
• Est. Priority Date: 03/19/2002
• Status: Expired due to Fees

• Current Assignee: Tien-Tsai Huang
• Original Assignee: Tien-Tsai Huang
• Inventors: Huang, Tien-Tsai
• Primary Examiner(s): Schwartz, Christopher P.
• Application Number:
  US10/101,257
• Time in Patent Office: 175 Days
• Field of Search: 188/1.11 L, 188/1.11 E, 340/442, 340/447, 340/448, 340/454, 731/462, 731/465
• US Class Current: 188/1.11L
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0433 Radio signals
• CPC Class Codes: F16D 66/021 using electrical detection or indication means

Abstract

In a monitoring apparatus, a conductive coupling member is embedded in a brake pad of a brake system and is spaced apart from a first brake member by a thickness of the brake pad when wearing of the brake pad has yet to reach a predetermined worn-out state. A wear detecting circuit is coupled to the coupling member for detecting wear condition of the brake pad, and is capable of outputting a wear signal when the brake system is activated and the brake pad ceases to space apart the coupling member from the first brake member. A pressure detecting unit generates a pressure signal in accordance with pressure condition in a pneumatic tire. A processing unit receives the wear signal and the pressure signal, and enables an indicating unit to indicate the pressure condition in the pneumatic tire and the wear condition of the brake pad.

Claims

1. A monitoring apparatus for a wheel unit of an automobile, the wheel unit including a pneumatic tire and a brake system for braking the pneumatic tire, the brake system including a conductive first brake member mounted on the pneumatic tire, and a second brake member provided with a brake pad that is disposed adjacent to the first brake member, the brake system being operable so as to enable the second brake member to move toward the first brake member such that the brake pad frictionally contacts the first brake member to brake the pneumatic tire, said monitoring apparatus comprising:

a conductive coupling member adapted to be embedded in the brake pad such that said conductive coupling member is spaced apart from the first brake member by a thickness of the brake pad when wearing of the brake pad has yet to reach a predetermined worn-out state;

a wear detecting circuit coupled electrically to said conductive coupling member for detecting wear condition of the brake pad, said wear detecting circuit being capable of outputting a wear signal when the brake system is activated and the brake pad ceases to space apart said conductive coupling member from the first brake member;

a pressure detecting unit for detecting pressure condition in the pneumatic tire and for generating a pressure signal in accordance with the pressure condition in the pneumatic tire;

a processing unit coupled electrically to said wear detecting circuit and said pressure detecting unit for receiving the wear signal and the pressure signal therefrom; and

an indicating unit coupled electrically to and enabled by said processing unit to indicate whether the brake pad has reached the predetermined worn-out state and to further indicate the pressure condition in the pneumatic tire.

2. The monitoring apparatus as claimed in claim 1, wherein said pressure detecting unit includes:

a pressure-responsive resonant switching device adapted to be mounted on the pneumatic tire and switchable between a normal impedance state, where the pressure in the pneumatic tire is within a predetermined normal operating pressure range, and an abnormal impedance state, where the pressure in the pneumatic tire is not within the predetermined normal operating pressure range;

an excitation unit adapted to be disposed adjacent to the pneumatic tire; and

a controller connected to said excitation unit and operable so as to supply an excitation signal to said excitation unit in order to enable said excitation unit to co-act with said resonant switching device by virtue of mutual induction according to the impedance state of said resonant switching device for inducing current in said resonant switching device as said resonant switching device is moved so as to be proximate with said excitation unit due to rotation of the pneumatic tire, said controller monitoring an output signal from said excitation unit and detecting presence of a change in the output signal of said excitation unit due to inducing of the current in said resonant switching device during a complete cycle of rotation of the pneumatic tire to enable said controller to determine the pressure condition in the pneumatic tire.

3. The monitoring apparatus as claimed in claim 1, wherein said conductive coupling member includes first and second conducting pieces, said wear detecting circuit being coupled electrically to said first and second conducting pieces such that, when the brake system is activated and the brake pad ceases to space apart said conductive coupling member from the first brake member, said first and second conducting pieces will be connected electrically to each other via the first brake member so as to enable said wear detecting circuit to generate the wear signal.

4. The monitoring apparatus as claimed in claim 1, wherein said conductive coupling member includes first and second conducting pieces, said wear detecting circuit including first and second detecting circuits coupled electrically and respectively to said first and second conducting pieces such that, when the brake system is activated and the brake pad ceases to space apart said conductive coupling member from the first brake member, said first and second conducting pieces will be connected electrically to each other via the first brake member, thereby connecting said second detecting circuit to said first detecting circuit to enable said first detecting circuit to generate the wear signal.

5. The monitoring apparatus as claimed in claim 4, wherein said second conducting piece is U-shaped, and includes a pair of parallel plates and an intermediate plate interconnecting said parallel plates, said intermediate plate being worn out when wearing of the brake pad has reached the predetermined worn-out state such that, when the brake system is not activated, said parallel plates will be disconnected from each other to enable said second detecting circuit to generate another wear signal.