Patent US3774978A successfully refreshed from Google Patents.
US3774978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Auxiliary hydraulic brake lock
Assignee: Minnesota Automotive Inc
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Filing: 1972-04-24
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Granted: 1973-11-27
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Expires: 1992-04-24
Abstract
Abstract An improved brake locking apparatus for hydraulic brake systems having an accumulator and an accumulator control unit. A pressure control element in the accumulator maintains a fluidic pressure in a closed brake system equal to that of a precharged pressure. A pair of sequentially operated lock valves in the accumulator control unit block fluid flow from the brake cylinders to the master cylinder when the braking system is locked, and sequentially unseat to gradually release the back pressure flow to the master cylinder when the braking system is unlocked. Control valves in the accumulator control unit cooperate with the sequentially operated lock valves to allow fluidic precharging of the accumulator by the master cylinder when the braking system is locked, and isolate the accumulator from the hydraulic braking system when the braking system is unlocked.
Inventors
- 👤 F Staunton
- 👤 V Tillman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:37
CPC Classifications
B; B60; B60T; B60T11/00; B60T11/10; B60T11/16; B60T11/228; B60T17/00; B60T17/08; B60T17/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
293 words
An improved hydraulic brake locking apparatus comprising: a. housing means forming a fluid chamber and having inlet and outlet ports to the fluid chamber, said inlet port adapted to be connected to the master cylinder of a hydraulic brake system, and said outlet port adapted to be connected to one or more brake cylinders of the brake system; b. locking valve means within said fluid chamber operable in a locked position to block fluid flow through said inlet port, and operable in an unlocked position to allow fluid flow through said inlet port; c. primary control means connected to said housing means and operable to move between first and second positions; said primary control means being operatively connected with said locking valve means such that said primary control means when in its first position, allows said locking valve means to operate in its locked position, and said primary control means when in its second position, causes said locking valve means to operate in its unlocked position; d. accumulator means having inlet means and operable to store and to thereafter release the energy of a fluid charge in response to a fluid pressure received by said inlet means; e. accumulator passage means connecting said accumulator inlet means with said housing means for establishing fluid communication between said accumulator means and said fluid chamber; and f. control valve means connected to control fluid flow through said accumulator passage means in response to said primary control means; said control valve means operable to directionally block fluid flow from the fluid chamber to the accumulator means when said primary control means is in its second position, and operable to allow fluid flow through said accumulator passage means when said primary control means is in its first position.
Claim 2
Dependent Claim
293 words
An improved hydraulic brake locking apparatus comprising: a. housing means forming a fluid chamber and having inlet and outlet ports to the fluid chamber, said inlet port adapted to be connected to the master cylinder of a hydraulic brake system, and said outlet port adapted to be connected to one or more brake cylinders of the brake system; b. locking valve means within said fluid chamber operable in a locked position to block fluid flow through said inlet port, and operable in an unlocked position to allow fluid flow through said inlet port; c. primary control means connected to said housing means and operable to move between first and second positions; said primary control means being operatively connected with said locking valve means such that said primary control means when in its first position, allows said locking valve means to operate in its locked position, and said primary control means when in its second position, causes said locking valve means to operate in its unlocked position; d. accumulator means having inlet means and operable to store and to thereafter release the energy of a fluid charge in response to a fluid pressure received by said inlet means; e. accumulator passage means connecting said accumulator inlet means with said housing means for establishing fluid communication between said accumulator means and said fluid chamber; and f. control valve means connected to control fluid flow through said accumulator passage means in response to said primary control means; said control valve means operable to directionally block fluid flow from the fluid chamber to the accumulator means when said primary control means is in its second position, and operable to allow fluid flow through said accumulator passage means when said primary control means is in its first position.
Claim 3
Dependent Claim
256 words
An improved hydraulic brake locking apparatus according to claim 1, wherein said fluid chamber has a generally cylindrical interior characterized by first axial passage means partitioning said interior into first and second axially aligned chambers in fluid communication with each other, and wherein said inlet port opens into said first chamber, said outlet port opens into said second chamber, and said accumulator passage means is fluidly continuous with said second chamber; and wherein said locking valve means comprises: a. a first lock valve seat defined by said first axial passage means; b. a first lock valve element axially movable in said first axial passage means toward and away from seating engagement with said first lock valve seat, said first lock valve element having an axial passageway therethrough and defining a second lock valve seat; said first lock valve element operable in an unseated condition when said locking valve means is in said unlocked position, and operable in a seated condition when said locking valve means is in said locked position; c. a second lock valve element axially movable toward and away from seating engagement with said second lock valve seat; said second lock valve element being operable in an unseated condition when said locking valve means is in said unlocked position, and operable in a seated condition when said locking valve means is in said locked position; and d. first yielding means connected to urge sAid second and said first lock valve elements toward seating engagement respectively with said second and said first lock valve seats.
Claim 4
Dependent Claim
144 words
An improved hydraulic brake locking apparatus according to claim 2, wherein said accumulator passage means includes a third chamber axially aligned with said second chamber and fluidly connected therewith by a second axial passage means, and conduit means connecting said third chamber with said accumulator means for fluid communication therebetween; and wherein said control valve means includes: a. a principal control valve seat defined by said second axial passage means; b. a principal control valve element axially movable in said second axial passage means toward and away from seating engagement with said principal control valve seat; c. second yielding means connected to yieldingly urge said principal control valve element toward seating engagement with said principal control valve seat; and d. means connected to cause said principal control valve element to unseat in response to movement of the primary control means to its first position.
Claim 5
Dependent Claim
123 words
An improved hydraulic brake locking apparatus according to claim 3, wherein said control valve means is further characterized by: a. a secondary control valve seat defined by said second axial passage means; and b. a secondary control valve element axially movable within said second axial passage means toward and away from seating engagement with said secondary control valve seat; said secondary control valve element having an axial passageway therethrough and defining said principal control valve seat; said secondary control valve element being urged toward seating engagement with said secondary control valve seat by said first yielding means, and operable to unseat against the bias of said first yielding means in response to positive differential fluid pressure between said third and second chambers respectively.
Claim 6
Dependent Claim
152 words
An improved hydraulic brake locking apparatus according to claim 3, wherein said primary control means when moving to its second position causes said second and said first lock valve elements to respectively sequentially unseat against the bias of said first yielding means; and wherein said means connected to cause said principal control valve element to unseat comprises: a. first stem means axially extending from said second lock valve element into said second chamber for axial movement with said second lock valve element; b. second stem means axially extending from said principal control valve element into said second chamber for axial movement with said principal control valve element; and c. guiding stop means within said second chamber cooperatively engaging said first and second stem means, and operable to impart unseating motion to said principal control valve element when said second and said first lock valve elements are positioned in their respective locked positions.
Claim 7
Dependent Claim
124 words
An improved hydraulic brake locking apparatus according to claim 5, wherein said first stem means axially extending from said second lock valve element comprises an annular stem having a cylindrical stem wall whose interior surface defines a cylindrical stem cavity; wherein said second stem means axially extending from said principal control valve element comprises a cylindrical stem that axially extends within said cylindrical stem cavity and slidingly engages said cylindrical stem wall of said annular stem; and wherein said second yielding means is contained within said cylindrical stem cavity and operatively engages said cylindrical stem of said principal control valve element and said second lock valve elements so as to yieldingly urge them in axially opposite directions as limited by said guiding stop means.
Claim 8
Dependent Claim
86 words
An improved hydraulic brake locking apparatus according to claim 6, wherein said guiding stop means comprises: a. elongated opening means normally extending and formed within the cylindrical stem of said principal control valve elemEnt; and b. extension means normally projecting from said cylindrical stem wall within said cylindrical stem cavity; said projecting extension means slidedly engaging said elongated opening means so as to limit, against the bias of said second yielding means, the maximum relative motion of said cylindrical and annular stems in axially opposing directions.
Claim 9
Dependent Claim
171 words
An improved hydraulic brake locking apparatus according to claim 1, wherein said accumulator means is further defined by: a. an accumulator housing forming an accumulator chamber having an interior wall surface and an accumulator inlet port to said accumulator chamber, said accumulator inlet port adapted to be detachably connected to said accumulator passage means; b. a pressure control element having sliding engagement with said interior wall surface and dividing said accumulator chamber into a first accumulator chamber and a second accumulator chamber, said pressure control element being movable in opposite directions to simultaneously expand one of said chambers while contracting the other; c. accumulator yielding means connected to urge said pressure control element in a direction tending to contract said first accumulator chamber and to expand said second accumulator chamber; and d. stop element means forming a portion of the interior wall surface and limiting movement of said pressure control element in the direction thereof urged by said accumulator yielding means and defining a minimum volume of said first accumulator chamber.
Claim 10
Dependent Claim
67 words
An improved hydraulic brake locking apparatus according to claim 8, wherein the interior wall surface of said accumulator wall chamber is generally cylindrical, wherein said pressure control element comprises a rigid generally cylindrical piston having axial sliding engagement with said interior wall surface so as to fluidically separate said first and second accumulator chambers, and wherein said accumulator yielding means comprises an axially expandable and compressible spring.
Claim 11
Dependent Claim
136 words
An improved hydraulic brake locking apparatus according to claim 1, wherein a pair of said accumulator means, said accumulator passage means, said control valve means, said locking valve means, and said housing means are operatively connected to a single primary control means to form a dual hydraulic brake locking apparatus, and wherein said primary control means includes symmetrical cam means movable between said first and second positions, said cam means being operatively connected with said pair of locking valve means so as to allow each of said pair of locking valve means to simultaneously operate in said locked position when the cam means are in said first position and operable to cause each of said pair of locking valve means to simultaneously operate in said unlocked position when the cam means are in said second position.
References Cited (Backward Citations)
US3597016A
Cited
US3497265A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |