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Patent US3914734A successfully refreshed from Google Patents.
US3914734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake failure warning device
Assignee: Individual
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Filing: 1973-05-02
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Granted: 1975-10-21
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Expires: 1993-05-02
Abstract
Abstract A brake failure warning device including an electrically conductive leaf spring which is spaced apart from an arcuate portion of the brake shoe and has one end biased towards the shoe. Connected to the one end of the leaf spring is a conductive plate, also spaced apart from the shoe, and a pin extending from the plate through the shoe a predetermined distance into the brake lining. The other end of the leaf spring is connected to, but electrically insulated from, the shoe via a non-conductive block. The leaf spring is electrically connected to an ignition switch and an alarm indicator located on the dashboard of a vehicle. When the brake lining has worn beyond the extension of the pin, the biasing force of the leaf spring urges the plate into contact with the shoe, thereby closing a circuit when the ignition switch is turned on to provide a brake failure warning signal. In an alternative embodiment, the pin is also made of a conductive material so that a second or back-up circuit is made through contact between the pin and the brake drum when the ignition switch is turned on.
Inventors
- 👤 Gonzalo Rigalt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:02
CPC Classifications
F; F16; F16D; F16D66/00; F16D66/02; F16D66/021; F16D66/022; F16D66/023; F16D66/024
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
180 words
A brake lining wear detector for a brake including an electrically conductive brake shoe and brake drum comprising: a. an electrically conductive leaf spring spaced apart from said brake shoe, said leaf spring being biased at one end towards said shoe; b. means for connecting the other end of said leaf spring to a first arcuate portion of said shoe, said connecting means electrically insulating said other end from said first portion; c. an electrically conductive plate connected to said one end of said leaf spring, said plate being mounted on the side of said spring facing said brake shoe and being spaced apart from said shoe; d. a pin connected to said conductive plate, said pin extending through an aperture in a second arcuate portion of said brake shoe a predetermined distance into the brake lining, said pin being slidable within the brake lining and spaced apart from said drum; and e. first means coupled to said brake shoe, said plate and said leaf spring for providing a brake lining wear signal when said plate contacts said brake shoe.
Claim 2
Dependent Claim
180 words
A brake lining wear detector for a brake including an electrically conductive brake shoe and brake drum comprising: a. an electrically conductive leaf spring spaced apart from said brake shoe, said leaf spring being biased at one end towards said shoe; b. means for connecting the other end of said leaf spring to a first arcuate portion of said shoe, said connecting means electrically insulating said other end from said first portion; c. an electrically conductive plate connected to said one end of said leaf spring, said plate being mounted on the side of said spring facing said brake shoe and being spaced apart from said shoe; d. a pin connected to said conductive plate, said pin extending through an aperture in a second arcuate portion of said brake shoe a predetermined distance into the brake lining, said pin being slidable within the brake lining and spaced apart from said drum; and e. first means coupled to said brake shoe, said plate and said leaf spring for providing a brake lining wear signal when said plate contacts said brake shoe.
Claim 3
Dependent Claim
16 words
The wear detector of claim 1 wherein said pin is made of an electrically conductive material.
Claim 4
Dependent Claim
34 words
The wear detector of claim 2 wherein the spaced apart distance between said conductive plate and said brake shoe is equal to said spaced apart distance between said conductive pin and said brake drum.
Claim 5
Dependent Claim
38 words
The wear detector of claim 3 further comprising second means coupled to said conductive pin, said conductive brake drum and said conductive spring for providing a brake lining wear signal when said conductive pin contacts said brake drum.
Claim 6
Dependent Claim
37 words
The wear detector of claim 4 wherein said conductive pin comprises an inner section of an electrically conductive material and an outer section of an electrically non-conductive material, said inner section extending longitudinally through said outer section.
Claim 7
Dependent Claim
34 words
The apparatus of claim 1 wherein the brake lining wear detector is connected to a plurality of wheels and said first means includes means for signaling the wear condition for each respective brake lining.
Claim 8
Dependent Claim
38 words
The apparatus of claim 1 wherein the brake lining wear detector is connected to a plurality of wheels and said first means includes means, common to all the wheels, for signaling the wear condition of the brake linings.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |