Patent US3581847A successfully refreshed from Google Patents.
US3581847A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic adjusting devices for shoe drum brakes
Assignee: Toyota Motor Corp
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Filing: 1968-04-29
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Granted: 1971-06-01
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Expires: 1988-04-29
Abstract
Abstract An automatic adjuster for a shoe drum brake which is provided with a hydraulic shoe expander, having a hydraulic piston mechanically connected with one of said shoes and a movable cylinder connected through a variable length transmission means to the remaining one of said shoes, the length of said transmission means being adjustable through a mechanical adder adapted for adding the working movements of said cylinder and said piston.
Inventors
- 👤 Tatsumi Torii
- 👤 Masakazu Ishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:17
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/38; F16D65/40; F16D65/52; F16D65/56; F16D65/561; F16D65/562; F16D65/14; F16D65/16; F16D65/22
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
176 words
In an automatic slack adjusting device for an automotive brake of the expansion type comprising a rotating drum and friction shoe means adapted for cooperation therewith, wherein said shoe means are expandingly applied against said drum in such a manner as to obtain action and reaction therebetween when said friction shoe means is actuated by two kinds of actuating means adapted for functioning independently of each other, said adjusting device comprising a slack actuating adjusting means being operable in both a parking and a service brake mode and having no functional interference therebetween, wherein the improvement comprises such that one of said two actuating means is provided with a slack adjusting means and a fluid actuator means having an operating piston and cylinder assembly, said piston being located in said cylinder separately from and in the enD of said cylinder which is opposite said adjusting means, said slack adjusting means being adjusted automatically by movement of said operating piston exclusively in the application of the brake when the wear of the brakeshoe exceeds a predetermined value.
Claim 2
Dependent Claim
176 words
In an automatic slack adjusting device for an automotive brake of the expansion type comprising a rotating drum and friction shoe means adapted for cooperation therewith, wherein said shoe means are expandingly applied against said drum in such a manner as to obtain action and reaction therebetween when said friction shoe means is actuated by two kinds of actuating means adapted for functioning independently of each other, said adjusting device comprising a slack actuating adjusting means being operable in both a parking and a service brake mode and having no functional interference therebetween, wherein the improvement comprises such that one of said two actuating means is provided with a slack adjusting means and a fluid actuator means having an operating piston and cylinder assembly, said piston being located in said cylinder separately from and in the enD of said cylinder which is opposite said adjusting means, said slack adjusting means being adjusted automatically by movement of said operating piston exclusively in the application of the brake when the wear of the brakeshoe exceeds a predetermined value.
Claim 3
Dependent Claim
58 words
An automatic slack adjusting device as set forth in claim 1, wherein said slack adjusting means comprises a cylindrical nut integrally formed with a toothed wheel, and a threaded stem in engagement with said cylindrical nut and one of said friction shoe means, said toothed wheel being mechanically connected with said operating piston of said fluid actuator means.
Claim 4
Dependent Claim
90 words
An automatic slack adjusting device as set forth in claim 2, wherein said toothed wheel is mechanically connected with said operating piston by a connecting means comprising two connecting members, one of which is connected at its one end with said operating piston, the opposite end of said one of said connecting members being pivotably connected with another of said connecting members at one end thereof, said other connecting member being made of resilient material, pivotably mounted on said fluid actuator means, and kept in engagement with said toothed wheel.
Claim 5
Dependent Claim
51 words
An automatic slack adjusting device as set forth in claim 3, wherein said one of said connecting members comprises an L-shaped bracket provided with a circular ring portion positioned between said one of friction shoe means and said operational piston and adapted to said piston by means of a stepped headpiece.
Claim 6
Dependent Claim
80 words
An automatic slack adjusting device as set forth in claim 4, wherein said threaded stem of the slack adjusting means is formed on its one end with a recess which is mechanically connected with one end part of said one of friction shoe means, and said stepped headpiece is formed with a recess mechanically connected with another of said friction shoe means, whereby the threaded stem and the stepped headpiece cannot be rotated when the slack adjusting device is actuated.
Claim 7
Dependent Claim
50 words
An automatic slack adjusting device as set forth in claim 1, wherein one of said actuating means is slidable relative to a backplate, and another of said actuating means is pivotably mounted on the first actuating means and comprises a bellcrank lever guided through a slot formed in the backplate.
Claim 8
Dependent Claim
87 words
An automatic slack adjusting device comprising a fluid actuator means including a hydraulic operational piston, a slack adjusting means located opposite to the fluid actuator means and including a cylindrical nut, a threaded stem in engagement therewith, an L-shaped connecting means, one end of which is mechanically connected with said piston, a resilient bellcrank lever pivotably mounted on said fluid actuator means and operatively connected at its one end with another end of said L-shaped connecting means, and a toothed wheel mechanically connected with said bellcrank lever.
Claim 9
Dependent Claim
87 words
An automatic slack adjusting device comprising a fluid actuator means including a hydraulic operational piston, a slack adjusting means located opposite to the fluid actuator means and including a cylindrical nut, a threaded stem in engagement therewith, an L-shaped connecting means, one end of which is mechanically connected with said piston, a resilient bellcrank lever pivotably mounted on said fluid actuator means and operatively connected at its one end with another end of said L-shaped connecting means, and a toothed wheel mechanically connected with said bellcrank lever.
Claim 10
Dependent Claim
45 words
An automatic slack adjusting device as set forth in claim 7, wherein said toothed wheel is turned when movement of the operational piston exceeds a predetermined value in the application of the brake, with said tooth wheel being turned only when the brake is released.
Claim 11
Dependent Claim
45 words
An automatic slack adjusting device as set forth in claim 7, wherein said toothed wheel is turned when movement of the operational piston exceeds a predetermined value in the application of the brake, with said tooth wheel being turned only when the brake is released.
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) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |