Reservoirs for liquid pressure control systems and a method of filling the same

• US 4,503,678 A
• Filed: 04/11/1984
• Issued: 03/12/1985
• Est. Priority Date: 01/21/1981
• Status: Expired due to Fees

• Current Assignee: Automotive Products PLC (Whitnash Plc)
• Original Assignee: Automotive Products PLC (Whitnash Plc)
• Inventors: Wimbush, Maurice J.
• Primary Examiner(s): Garrett, Robert E.
• Assistant Examiner(s): Meyer, Richard S.
• Application Number:
  US06/599,249
• Time in Patent Office: 335 Days
• Field of Search: 188/352, 137/852, 137/854, 303/64, 60/584, 60/585, 60/586, 60/587, 60/592
• US Class Current: 60/584
• CPC Class Codes: B60T 11/26 Reservoirs integral with master controls B60T11/22
• CPC Class Codes: B60T 11/30 Bleed valves for hydraulic brake systems
• CPC Class Codes: B60T 17/222 by filling or bleeding of hydraulic systems
• CPC Class Codes: F16D 25/12 Details not specific to one of the before-mentioned types
• CPC Class Codes: F16K 15/148 the closure elements being fixed in their centre
• CPC Class Codes: Y10T 137/789 Central mount

Abstract

A liquid reservoir for a hydraulic master cylinder, having a body with a detachable cap for refilling the reservoir, and a diaphragm secured in position by the cap and dividing the reservoir into an air chamber, vented to atmosphere via a hole in the cap and a liquid chamber connected to the master cylinder. An inlet port is provided in the wall of the reservoir for initial charging of the liquid into the liquid chamber without removal of the cap, the port being closed by a plug after the liquid reservoir has been filled. The method of filling a hydraulic control system which has such a reservoir is by the application of vacuum to the system via the inlet port, introducing liquid into the system through the port and subsequently sealing the port with the plug.

Claims

1. A method of prefilling a hydraulic control system prior to installing said hydraulic control system for normal use, said hydraulic control system comprising a hydraulic master cylinder, a remote hydraulic slave cylinder connected to the master cylinder via a conduit, and a hydraulic fluid reservoir connected to the master cylinder, wherein said reservoir comprises a body having a mouth for replenishing said reservoir with hydraulic fluid, a removable cap normally closing said mouth, a removable diaphragm disposed in said body such as to divide said body into first and second chambers, said diaphragm being held in place by said cap when in position closing said mouth, a vent port in said cap venting said first chamber to atmospheric air, an outlet port and an inlet port in said second chamber, said outlet port placing said second chamber in communication with said master cylinder and said inlet port placing said second chamber in communication with the ambient, said method comprising connecting said system through said vent port in said cap to a source of vacuum for evacuating atmospheric air from said first chamber and for checking the integrity of said diaphragm, subsequently connecting said inlet port to said source of vacuum for evacuating atmospheric air from said second chamber and said system and for checking the integrity of said system, subsequently connecting said inlet port to a source of hydraulic fluid for filling said second chamber and said system with said hydraulic fluid while maintaining said first chamber connected to said source of vacuum, disconnecting said inlet port from said source of hydraulic fluid and said first chamber from said source of vacuum, and sealing said system from the ambient by closing said inlet port by means of a plug, said inlet port and said plug being so constructed as to allow flow of hydraulic fluid from said second chamber to the ambient upon excess hydraulic fluid pressure in said second chamber and prevent reverse flow from the ambient into said second chamber.

2. The method of claim 1 wherein said hydraulic control system is a motor vehicle clutch release mechanism.

3. A method of initially charging a hydraulic fluid control system with hydraulic fluid, said hydraulic fluid control system comprising a hydraulic master cylinder, a remote hydraulic slave cylinder connected to the master cylinder via a conduit, and a reservoir of hydraulic fluid feeding the master cylinder, said reservoir comprising a reservoir body having a mouth, a detachable cap mounted on the mouth of the body and removable for replenishing the reservoir with hydraulic fluid, a diaphragm secured in position by said cap and removable for replenishing the reservoir with hydraulic fluid, said diaphragm dividing the reservoir body into two chambers, one of said chambers being an air chamber vented to atmosphere through an aperture in the cap and the other of said chambers being a hydraulic fluid chamber containing hydraulic fluid and connectable to the master cylinder, an inlet port defined in a wall of the reservoir body for the initial charging of hydraulic fluid into the hydraulic fluid chamber without necessitating the removal of the cap and diaphragm, and a closure plug located in the inlet port for subsequent sealing thereof after the initial charging, wherein the inlet port and the closure plug are so constructed and arranged as to allow excess hydraulic fluid in the hydraulic fluid chamber to exit the reservoir past the closure plug when a predetermined pressure differential exists across the closure plug, said method comprising applying vacuum to the system via the inlet port, introducing hydraulic fluid into the system via the inlet port, and subsequently sealing the system by installing the plug in the inlet port, said inlet port and said plug being arranged in assembly to allow the hydraulic fluid to flow through the assembly from the hydraulic fluid chamber to ambient upon excessive hydraulic fluid pressure in the hydraulic fluid chamber.

4. The method of claim 3 further comprising the steps of applying vacuum to said hydraulic fluid chamber through said aperture in the cap prior to applying vacuum to the system, and checking the integrity of the diaphragm while vacuum is applied to said air chamber.

5. The method of claim 4 further comprising the step of maintaining vacuum applied to said air chamber while introducing hydraulic fluid into the system, and cutting off application of vacuum to said air chamber prior to installing the plug in the inlet port.