BRAKE LINING WEAR INDICATOR
First Claim
Patent Images
1. In a brake:
- a member to be braked;
a friction member having a lining for engagement with said member to be braked;
probe means carried by said friction member for engagement with said member to be braked after a predetermined amount of lining wear;
indicator means;
a voltage source;
transistorized control means operatively connected between the voltage source, the probe means, the indicator means, and an electrical ground for actuating said indicator means upon said predetermined amount of lining wear; and
said transistorized control means including transistor means having an input element and an output element, said output element being in series flow relationship with said indicator means, said voltage source and said ground, and bias means connected to said input element, said input element being responsive to said probe means to switch the transistor means upon engagement of the probe means with the member to be braked.
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Abstract
This invention relates to a device providing a warning signal to the vehicle operator when the brake lining has worn a predetermined amount, and more specifically, concerns an electronic control means which is responsive to a probe means inserted in the brake lining for controlling an indicator means that provides a visual indication.
22 Citations
14 Claims
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1. In a brake:
- a member to be braked;
a friction member having a lining for engagement with said member to be braked;
probe means carried by said friction member for engagement with said member to be braked after a predetermined amount of lining wear;
indicator means;
a voltage source;
transistorized control means operatively connected between the voltage source, the probe means, the indicator means, and an electrical ground for actuating said indicator means upon said predetermined amount of lining wear; and
said transistorized control means including transistor means having an input element and an output element, said output element being in series flow relationship with said indicator means, said voltage source and said ground, and bias means connected to said input element, said input element being responsive to said probe means to switch the transistor means upon engagement of the probe means with the member to be braked.
- a member to be braked;
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2. In a brake:
- a member to be braked;
a friction member having a lining for engagement with said member to be braked;
probe means carried by said friction member for engagement with said member to be braked after a predetermined amount of lining wear;
indicator means;
a voltage source;
transistorized control means operatively connected between the voltage source, the probe means, the indicator means, and an electrical ground for actuating said indicator means upon said predetermined amount of lining wear; and
said transistorized control means including a transistor having an input element and an output element, said output element being in series flow relationship with said indicator means, said Voltage source, and said ground; and
bias means connected to said input element to keep said transistor in a normally nonconducting state, said input element being responsive to said probe means to switch the transistor means to a conducting state upon engagement of the probe means with the member to be braked.
- a member to be braked;
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3. A brake lining wear indicator as claimed in claim 2, wherein said bias means comprises:
- a first and second resistor, in series flow relationship, interposed between said input and said ground; and
a third resistor interposed between said supply and the junction of said first and second resistors.
- a first and second resistor, in series flow relationship, interposed between said input and said ground; and
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4. A brake lining wear indicator as claimed in claim 3, wherein said probe means is interposed between said third resistor and said junction of said first and second resistors.
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5. A brake lining wear indicator as claimed in claim 4, wherein said probe means, after a predetermined period of frictional engagement with said member to be braked, is separated thereby and provides an open circuit to said junction, which upon disengagement of said probe means and said member to be braked, will cause said transistor to remain in a conducting state.
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6. In a brake:
- a member to be braked;
a friction member having a lining for engagement with said member to be braked;
probe means carried by said friction member for engagement with said member to be braked after a predetermined amount of lining wear;
indicator means;
a voltage source;
transistorized control means operatively connected between the voltage source, the probe means, the indicator means, and an electrical ground for actuating said indicator means upon said predetermined amount of lining wear; and
said transistorized control means including transistor means having an input element and an output element, said output element being in series flow relationship with said indicator means, said voltage source, and said ground, and bias means connected to said input element to keep said transistor in a normally nonconducting state, and input element being responsive to said probe means after a predetermined period of frictional engagement of the latter with the member to be braked provides an open circuit to said bias means to switch said transistor to a conducting state.
- a member to be braked;
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7. A brake lining wear indicator as claimed in claim 6, wherein said bias means comprises a first and second resistor, in series flow relationship, interposed between said input and said source of voltage.
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8. A brake lining wear indicator as claimed in claim 7, wherein said probe means is connected to the junction intermediate said first and second resistors.
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9. A brake lining wear indicator as claimed in claim l, and further including a test means interposed between said source of voltage and said bias means to check the integrity of said transistorized control means and said indicator means.
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10. A brake lining wear indicator as claimed in claim 6, and further including a test means interposed between said source of voltage and said input element to check the integrity of said transistorized control means and said indicator means. ll. A probe carried in the friction lining of a brake shoe for engagement with a member to be braked upon a predetermined amount of lining wear to actuate a warning device, said probe comprising:
- first and second wires;
first and second terminals secured, respectively, to said first and second wires;
retainer means in which said first and second terminals are carried in an opposing relationship;
a generally U-shaped conductor member being embodied in a nonconducting plug;
said plug installed in a an opening in said friction member and having a flange for abutment against said friction member;
said conductor member having a flat portion exposed for engagement with said member to be braked, and first and second legs for contacting said first and second terminals; and
said plug and said conductor member frictionally cooperate With said terminals and said retainer means to secure said plug with respect to said friction member and establish a predetermined relationship between said flat portion and said lining of said friction member.
- first and second wires;
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12. A probe carried in the friction lining of a brake shoe for engagement with a member to be braked upon a predetermined amount of lining wear to actuate a warning device, said probe comprising:
- a wire;
a terminal secured to said wire;
retainer means in which said terminal is carried;
a generally J-shaped conductor member being embodied in a nonconductive plug;
said plug installed in an opening in said friction member and having a flange for abutment against said friction member;
said conductor member having a flat portion exposed for engagement with said member to be braked, and a leg for contacting said terminal; and
said plug and said conductor member frictionally cooperating with said terminal and said retainer means to secure said plug with respect to said friction member and establish a predetermined relationship between said flat portion and said lining of said friction member.
- a wire;
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13. In a brake:
- a member to be braked;
a friction member having a lining for engagement with the member to be braked;
probe means carried by said friction member;
said probe means including an electrically conductive element for frictional engagement with said member to be braked after a predetermined amount of lining wear;
said member to be braked severing said element after frictional engagement between the latter and the member to be braked;
indicator means; and
control means operably connecting said element with the indicator means for actuating the latter upon severing of the element.
- a member to be braked;
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14. In a brake:
- a member to be braked;
a friction member having a lining for engagement with the member to be braked;
probe means carried by said friction member;
said probe means including an electrically conductive element for frictional engagement with said member to be braked after a predetermined amount of lining wear;
said member to be braked severing said element after frictional engagement between the latter and the member to be braked;
indicator means; and
control means operably connecting said element with the indicator means for actuating the latter during a brake actuation only after the lining has worn said predetermined amount to permit the element to engage the member to braked, said control means maintaining actuation of said indicator means after said element is severed.
- a member to be braked;
Specification