Patent US3900084A successfully refreshed from Google Patents.
US3900084A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improvements in hydraulically and mechanically actuatable brake systems with automatic adjusters
Assignee: Girling Ltd
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Filing: 1974-02-25
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Granted: 1975-08-19
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Expires: 1994-02-25
Abstract
Abstract In a hydraulic actuator for a disc brake or the like, a reversible face cam serves the dual purpose of effecting relative rotation between two screw-threaded members of an automatic adjuster and of an auxiliary mechanical actuator for a handbrake. To render the adjuster load insensitive the preferred embodiments have an auxiliary piston biassed by an auxiliary spring to prevent the reversible face cam from being effective when the hydraulic pressure exceeds a relatively low predetermined brake pressure at which caliper deflection is negligible.
Inventors
- 👤 Glyn Phillip Reginald Farr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:32
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/38; F16D65/40; F16D65/52; F16D65/56; F16D65/567; F16D65/14; F16D65/16; F16D65/18; F16D2121/00; F16D2121/02; F16D2121/14; F16D2123/00; F16D2125/00; F16D2125/18; F16D2125/20; F16D2125/34; F16D2125/36; F16D2125/40; F16D2127/00; F16D2127/007
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
193 words
An actuator mechanism for a vehicle brake comprising in combination, a hydraulic actuator having actuator components being movable apart to apply an associated brake by fluid pressure applied between said components, an auxiliary mechanical actuator and an automatic slack adjuster which is operative between one of said components of the hydraulic actuator and said mechanical actuator, wherein said mechanical actuator comprises a reversible face cam aligned with the hydraulic actuator axis and comprising first and second cam members having co-operative helically inclined surfaces thereon, said first cam member being axially fixed relative to said other hydraulic actuator component, one of said cam members being turnable for mechanical actuation of the brake, and wherein said slack adjuster comprises a first non-rotatable adjuster member and a second rotatable adjuster member in screw-threaded engagement therewith, said first adjuster member being associated with said one actuator component, said second adjuster member being disposed to be axially abutted by said second cam member, means being provided to enable the latter to turn the second adjuster member in one direction upon hydraulic operation when adjustment is required but not to turn the second adjuster member in the opposite direction.
Claim 2
Dependent Claim
193 words
An actuator mechanism for a vehicle brake comprising in combination, a hydraulic actuator having actuator components being movable apart to apply an associated brake by fluid pressure applied between said components, an auxiliary mechanical actuator and an automatic slack adjuster which is operative between one of said components of the hydraulic actuator and said mechanical actuator, wherein said mechanical actuator comprises a reversible face cam aligned with the hydraulic actuator axis and comprising first and second cam members having co-operative helically inclined surfaces thereon, said first cam member being axially fixed relative to said other hydraulic actuator component, one of said cam members being turnable for mechanical actuation of the brake, and wherein said slack adjuster comprises a first non-rotatable adjuster member and a second rotatable adjuster member in screw-threaded engagement therewith, said first adjuster member being associated with said one actuator component, said second adjuster member being disposed to be axially abutted by said second cam member, means being provided to enable the latter to turn the second adjuster member in one direction upon hydraulic operation when adjustment is required but not to turn the second adjuster member in the opposite direction.
Claim 3
Dependent Claim
29 words
An adjuster mechanism according to claim 1 in which said face cam further comprises rolling members between said co-operative helically inclined surfaces on said first and second cam members.
Claim 4
Dependent Claim
108 words
An adjuster mechanism according to claim 1 in which the last mentioned means comPrises a first spring torsionally operative between said cam members in a direction to urge the latter apart through the co-operative effect of said helical surfaces thereon and a second spring biassing the second cam member towards the first cam member and strong enough to overcome the first spring such that, upon the occurrence of excess axial travel between the first cam member and the first adjuster member, the second adjuster member relieves the second cam member of the force of the second spring to enable the first spring to turn the second cam member.
Claim 5
Dependent Claim
72 words
An actuator mechanism according to claim 3 in which said slack adjuster further comprises an intermediate member relatively axially displaceably but non-relatively rotatably keyed to said second adjuster member, said second spring acting on said second cam member via said intermediate member, said second adjuster member axially abutting said intermediate member to relieve the second cam member of the force of the second spring upon the occurrence of said excess axial travel.
Claim 6
Dependent Claim
21 words
An actuator mechanism according to claim 4 in which said intermediate member comprises a collar which encircles said second adjuster member.
Claim 7
Dependent Claim
62 words
An actuator mechanism according to claim 3 in which said second spring acts on said second cam member via said second adjuster member and in which said slack adjuster further comprises a one-way ratchet type rotary clutch arranged between the second cam member and the second adjuster member, the ratchet type clutch being stepped upon the occurrence of said excess axial travel.
Claim 8
Dependent Claim
34 words
An actuator mechanism according to claim 1 in which said first cam member is journalled for rotation in said other hydraulic actuator component and is the one turnable for mechanical actuation of the brake.
Claim 9
Dependent Claim
68 words
An actuator mechanism according to claim 1 in which said first cam member is non-rotatable and is effectively part of said other hydraulic actuator component and said second cam member is the one turnable for mechanical actuation of the brake, and in which a lost motion connection is provided and is associated with the mechanical actuator to enable the second cam member to turn when adjustment is required.
Claim 10
Dependent Claim
34 words
An actuator mechanism according to claim 8 in which a lever is provided coaxial with the reversible face cam and the lost motion connection is provided between the lever and the second cam member.
Claim 11
Dependent Claim
51 words
An actuator mechanism according to claim 9 which further comprises first and second coaxial spindles and in which the lever is secured to said first spindle and said second spindle is provided on and journals the second cam member said lost motion connection being provided between said first and second spindles.
Claim 12
Dependent Claim
55 words
An actuator mechanism according to claim 9 which further comprises a spindle provided on and journalling the second face cam member, said lever being rotatably mounted on said spindle, and a second lever secured to said spindle and engageable by the first mentioned lever so that the lost motion connection is between said two levers.
Claim 13
Dependent Claim
52 words
An actuator mechanism according to claim 8 which further comprises a spindle provided on and journalling the second face cam member and a lever secured to said spindle and having a free end, and a brake applying member, said lost motion connection being between said free end and said brake applying member.
Claim 14
Dependent Claim
32 words
An actuator mechanism according to claim 1 in which said second adjuster member comprises a strut having an external screw thread mating with an internal screw thread in said first adjuster member.
Claim 15
Dependent Claim
72 words
An actuator mechanism according to claim 1 in which said second adjuster member is slidably sealed to the said other actuator component and has an effective cross sectional area less than that of the hydraulic actuator, whereby the screw thread connection between the first and second adjuster members is loaded by the hydraulic pressure to prevent said second adjuster member from turning in said opposite direction when the brake is applied hydraulIcally.
Claim 16
Dependent Claim
21 words
An actuator mechanism according to claim 1 in which said first adjuster member effectively comprises part of said one actuator component.
Claim 17
Dependent Claim
49 words
An actuator mechanism according to claim 1 in which the slack adjuster further comprises an auxiliary piston and an auxiliary spring axially biassing said auxiliary piston to prevent the second cam member from being displaced from its resting position when the hydraulic pressure exceeds a predetermined relatively low value.
Claim 18
Dependent Claim
91 words
An actuator mechanism according to claim 1 in which the slack adjuster further comprises an auxiliary piston displaceably mounted in said second adjuster member for movement by the hydraulic pressure against the second cam member to hold the latter in its resting position and an auxiliary spring biassing the auxiliary piston against the hydraulic pressure to prevent the auxiliary piston from holding the second cam member in its resting position so long as the hydraulic pressure is below a predetermined relatively low value at which it can overcome the auxiliary spring.
Claim 19
Dependent Claim
94 words
An actuator mechanism according to claim 14 in which said first adjuster member is separate from said one actuator component and acts as an auxiliary piston to hold the second cam member in its resting position and in which the slack adjuster further comprises an auxiliary spring biassing said first adjuster member against said one actuator component to prevent the first adjuster member from holding the second cam member in its resting position so long as the hydraulic pressure is below a predetermined relatively low value at which it can overcome the auxiliary spring.
Claim 20
Dependent Claim
16 words
An actuator mechanism according to claim 1 in which said one actuator component comprises a piston.
Claim 21
Dependent Claim
28 words
An actuator mechanism according to claim 19 in which said other actuator component comprises a cylinder body having a cylinder bore in which said actuator piston is slidable.
Claim 22
Dependent Claim
25 words
An actuator mechanism according to claim 20 in which said cylinder body is constructed as a caliper of a reaction type, spot type disc brake.
Claim 23
Dependent Claim
103 words
In a hydraulic brake actuator for a vehicle brake system: reversible face cam means; manual means for producing rotation at said reversible face cam means to produce axial thrust for auxiliary mechanical actuation of the brake system; a slack adjuster mechanism having a screw-thread connection therein, said axial thrust being applied via said slack adjuster mechanism; resilient means operative upon said reversible face cam means to produce rotation thereat upon hydraulic actuation of the brake system; and means for transmitting the last-mentioned rotation to said screw thread connection when the travel of the brake system upon hydraulic actuation thereof exceeds a predetermined value.
Claim 24
Dependent Claim
103 words
In a hydraulic brake actuator for a vehicle brake system: reversible face cam means; manual means for producing rotation at said reversible face cam means to produce axial thrust for auxiliary mechanical actuation of the brake system; a slack adjuster mechanism having a screw-thread connection therein, said axial thrust being applied via said slack adjuster mechanism; resilient means operative upon said reversible face cam means to produce rotation thereat upon hydraulic actuation of the brake system; and means for transmitting the last-mentioned rotation to said screw thread connection when the travel of the brake system upon hydraulic actuation thereof exceeds a predetermined value.
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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |