Patent EP0089478A1 successfully refreshed from Google Patents.
EP0089478A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A brake pressure control valve for a double piping braking system
Assignee: Nissan Motor Co Ltd
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Filing: 1983-02-07
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Granted: —
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Expires: 2003-02-07
Abstract
Abstract In a brake pressure control valve (10) having two valve units (16, 16') arranged therein, there is disposed a free piston self-centering promoting arrangement. The arrangement comprises a shoulder portion (30a, 30a') of a hollow member (30) which is retained in each valve unit to retain the substantially all essential parts in a casing (20,20'), a radially outwardly projected portion (32b, 32b') of the free piston (32, 32') which is axially slidably received in the hollow plug with its outside end contacting with the pair, and an annular spring seat (37, 37') which supports one end of a biasing spring (38, 38') of the pressure control piston of the unit, wherein the spring seat is in abutment with both the shoulder portion and the radially outwardly projected portion at the same time when the free piston assumes its home position.
Inventors
- 👤 Hitoshi Kubota
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 12:36
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/26; B60T11/00; B60T11/10; B60T11/28; B60T11/34
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
176 words
A brake pressure control valve for a double piping hydraulic braking system, comprising: a housing (14) having a bore (14a) formed therein; a pair of substantially identical valve units (16,16') coaxially and symmetrically arranged in said bore, each valve unit including a valve body (34,34'), a pressure control piston (20,20') and a spring (38,38') which are constructed to produce a controlled outlet hydraulic pressure in accordance with the magnitude of a hydraulic pressure applied thereto; a pair of free pistons (32,32') respectively associated with the paired valve units and contacting each other to be movable therewith, said free pistons supporting the associated valve bodies and one ends of the associated springs to cause one of said valve units to produce, when the other valve unit fails to operate, an outlet hydraulic pressure which is equal to the applied pressure in magnitude; and a self-centering promoting means ((37,30a,32b), (37',30a',32b')] which causes each of the springs to apply no force to the corresponding free piston when said free piston moves away from its home position toward the pair.
Claim 2
Dependent Claim
176 words
A brake pressure control valve for a double piping hydraulic braking system, comprising: a housing (14) having a bore (14a) formed therein; a pair of substantially identical valve units (16,16') coaxially and symmetrically arranged in said bore, each valve unit including a valve body (34,34'), a pressure control piston (20,20') and a spring (38,38') which are constructed to produce a controlled outlet hydraulic pressure in accordance with the magnitude of a hydraulic pressure applied thereto; a pair of free pistons (32,32') respectively associated with the paired valve units and contacting each other to be movable therewith, said free pistons supporting the associated valve bodies and one ends of the associated springs to cause one of said valve units to produce, when the other valve unit fails to operate, an outlet hydraulic pressure which is equal to the applied pressure in magnitude; and a self-centering promoting means ((37,30a,32b), (37',30a',32b')] which causes each of the springs to apply no force to the corresponding free piston when said free piston moves away from its home position toward the pair.
Claim 3
Dependent Claim
131 words
A brake pressure control valve as claimed in Claim 1, in which said self-centering promoting means comprises: a hollow member (30,30') retained in the mouth of said casing to retain the substantially essential all parts of the valve unit in the casing, said hollow member having a shoulder portion (30a,30a') which protrudes into the interior of said casing; a radially outwardly projected portion (32b,32b') of the free piston which is axially slidably received in said hollow member with its outside end contacting with the pair free piston; and an annular spring seat (37,37') on which said one end of said spring is seated, said spring seat being in abutment with both said shoulder portion and said radially outwardly projected portion at the same time when said piston assumes its home position.
Claim 4
Dependent Claim
51 words
A brake pressure control valve as claimed in Claim 2, in which said hollow member is formed with a radially inwardly projected portion (30b,30b') to which said radially outwardly projected portion of the free piston is engageable to limit the axially outwardly displacement of the free piston relative to the casing.
Claim 5
Dependent Claim
52 words
A brake pressure control valve as claimed in Claim 1, in which said pressure control piston is formed with an axially extending through passage (20e,20e') which connects the hydraulic pressure inlet and outlet ports of said valve unit when said valve body is disengaged from the mouth portion of said through passage.
Claim 6
Dependent Claim
85 words
A brake pressure control valve as claimed in Claim 4, in which said valve unit further comprises: an annular spring seat (28,28') coaxially and removably mounted on the mouth portion of said pressure control piston to support thereon the other end of said spring; and a valve seat (29,29') fixed to said annular spring seat so that, upon engagement with said valve body, said through passage of the pressure control piston is closed, and, upon disengagement with said valve body, said through passage is open.
Claim 7
Dependent Claim
79 words
A brake pressure control valve as claimed in Claim 5, in which said valve unit further comprises: a cylindrical valve body supporter (33,33') coaxially connected at its base portion to the free piston to be movable therewith and containing therein said valve body; and a spring (36,36') compressed between said valve body and said free spring to bias said valve body causing a head of said valve body to be projected outwardly from said supporter toward said valve seat.
Claim 8
Dependent Claim
139 words
A brake pressure control valve as claimed in Claim 6, in which said self-centering promoting means comprises: a hollow member (30,30') retained in the mouth of said casing to retain the substantially essential all parts of the valve unit in the casing, said hollow member having a shoulder portion (30a,30a') which protrudes into the interior of said casing; a radially outwardly projected portion (32b,32b') of the free piston which is axially slidably received in said hollow plug with its outside end contacting with the pair free piston; and an annular spring seat (37,37') axially movably disposed on the cylindrical valve body supporter and supporting thereon said one end of said spring, said spring seat being in abutment with both said shoulder portion and said radially outwardly projected portion at the same time when said piston assumes its home position.
Claim 9
Dependent Claim
51 words
A brake pressure control valve as claimed in Claim 7, in which said hollow member is formed with a radially inwardly projected portion (30b,30b') to which said radially outwardly projected portion of the free piston is engageable to limit the axially outward displacement of the free piston relative to the casing.
References Cited (Backward Citations)
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