Accumulator charging and relief valve

• US 3,896,845 A
• Filed: 06/13/1974
• Issued: 07/29/1975
• Est. Priority Date: 06/13/1974
• Status: Expired due to Term

• Current Assignee: Donald L. Parker
• Original Assignee: Donald L. Parker
• Inventors: Parker, Donald L.
• Primary Examiner(s): Klinksiek, Henry T.
• Application Number:
  US05/479,035
• Time in Patent Office: 411 Days
• Field of Search: 137/493.3,493.4,493.5,493.6
• US Class Current: 137/493.3
• CPC Class Codes: B60T 13/148 Arrangements for pressure supply
• CPC Class Codes: F16K 17/168 combined with manually-controlled valves, e.g. a valve combined with a safety valve
• CPC Class Codes: Y10T 137/7774 Supporting valve spring carried by supporting valve
• CPC Class Codes: Y10T 137/7777 Both valves spring biased

Abstract

A combination charging and relief valve for an accumulator of a hydraulic power brake booster. The valve includes a threaded body member having an end portion located within the brake booster housing separating a passage fluidly connected to a hydraulic fluid pressure source and another passage fluidly connected to a storage chamber or accumulator of the brake booster. The end portion of the valve has passage means therethrough, including an axial bore. A valve element is supported in the axial bore and may be reciprocated between closed and open positions against a spring normally holding the valve in a closed position. Valve seat portions are formed on the end of the valve body and the movable valve element providing a metal-to-metal sealing contact to prevent fluid leakage with the valve element in a closed position. The valve element has an O-ring type seal about it which contacts the end surfaces of the valve element and the valve body to form a sealing contact therewith encircling the metal-to-metal contact between the valve element and the valve body when the valve is in a closed operative position. A check valve within the movable valve element permits fluid to flow from the accumulator to the pressure source when the pressure in the accumulator exceeds a predetermined pressure level.

Claims

1. In a charging valve adapted to be removably attached to a brake booster housing for controlling the introduction of pressurized fluid to an accumulator, a valve body having an enlarged cylindrical head with a threaded portion adapted to be removably attached in a corresponding threaded bore in said housing, said valve body having an elongated end portion extending into a cavity in the brake booster housing between a first passage fluidly connected to a fluid pressure source and a second passage fluidly connected to an accumulator;

annular seal means encircling said end portion and engaging the surrounding surface of the housing to prevent fluid communication therebetween;

said end portion having passage means therein including an axially directed cylinder bore and a radially directed port connected to said first passage;

a movable valve member having an elongated cylindrical portion extending into said bore for reciprocal movement therein, and having a passage including an axially directed portion fluidly connected to said first passage and a radially directed portion normally covered by the surrounding end of said valve body when in a closed operative position and moved with said movable valve member to an open operative position away from said end portion of said valve body to interconnect said first and second passages, said end portion of said movable valve member having a valve seat formed thereabout, a corresponding valve seat formed on the end of said valve body adapted to be engaged by the valve seat of the movable valve member when in a closed operative position thereby providing a primary metal-to-metal seal therebetween, a spring biasing said movable valve member toward its closed operative position with the valve seats engaged, an annular resilient seal member encircling said valve seats when in a closed operative position, inclined surfaces on said movable valve member and on said valve body contacting opposite sides of said seal member when in a closed operative position and thereby compressing portions of said seal member to provide a secondary seal about said primary metal-to-metal seal.

2. In a charging and relief valve assembly for a brake booster and a housing and an accumulator, a valve body having an enlarged cylindrical head with a threaded portion adapted to be attached in a corresponding threaded bore in said housing, thus providing an easily removable connection therebetween, said valve body having an elongated end portion extending into a cavity in the brake booster housing between a first passage fluidly connected to a fluid pressure source and a second passage fluidly connected to the accumulator annular seal means encircling said end portion and engaging the surrounding surface of the housing to prevent fluid flow therebetween, said end portion having an axially directed bore therein and a radially directed passage fluidly connected to said first passage, a movable valve member having an elongated cylindrical portion extending into said bore for reciprocal movement therein and having a passage including an axially directed portion fluidly connected to said first passage and a radially directed portion normally covered by the surrounding end of said valve body when in a closed operative position and moved with said movable valve member to an open operative position away from said valve body to interconnect said first passage and said second passage, said elongated end portion having a valve seat formed thereabout, a corresponding valve seat formed on the end of said valve body adapted to be engaged by the valve seat of the movable valve member when in a closed operative position thereby providing a primary metal-to-metal seal therebetween, a spring extending between said housing and the movable valve member biaSing the valve member toward a closed operative position with said valve seat portions engaging one another, an annular resilient seal member encircling said valve seats when in a closed operative position, annular inclined surfaces on said valve body and said movable member contacting opposite sides of said seal member when in a closed operative position and thereby compressing portions of the seal member to provide a secondary seal encircling the primary metal-to-metal seal, relief valve means in said movable valve member including a spherical valve member biased by a spring against the end of said movable valve member, a bleed passage in the end of said movable valve member interconnecting said first and second passages whereby a predetermined fluid pressure differential across said relief valve moves it away from said bleed passage to permit fluid flow from said second passage to said first passage.