Full-function valve with quick drive away for heavy duty semi-trailer brake systems
AssigneeMidland Brake, Inc.
InventorMichael J. Moody
Life of this patent
Estimating the term…
Abstract
A full function valve incorporating a proportioning valve module that initially directs supply air pressure during initial system charging to the spring brake chambers to prepare the spring brakes for prompt release when there is sufficient system supply air pressure to operate the service brakes. The proportioning valve module then opens to increase supply air pressure to the reservoir, while charging of the spring brake chambers continues, until the service brakes become operable and the spring brakes disengage.
Claims14
In a unitary full function valve having a valve body with multiple ports, including individual ports for fluid communication to a spring brake chamber, a service brake chamber, to a reservoir and to exhaust, and for receiving pressurized supply air and control air, said ports being in communication by passageways and valves so as to connect:
- supply air to said spring brake chamber, when said supply air is at a predetermined pressure,
- supply air and air stored in said reservoir to said service brake chamber, when said supply air is at said predetermined pressure and said control air is at a selected pressure;
- the improvement comprising:
- a proportioning valve module in communication with said supply air and said reservoir, said proportioning valve module having a first mode of operation for limiting the pressurization of said reservoir by supply air during an initial charging period while providing full pressurization of said spring brake chamber by said supply air, said proportioning valve module having a second mode of operation for providing an increase in pressurization of said reservoir when said spring brake chamber has been partially pressurized.
A unitary full function valve, comprising:
- a valve body with multiple ports, including individual ports for fluid communication to a spring brake chamber, a service brake chamber, to a reservoir and to exhaust, and for receiving pressurized supply air and control air, said ports being in communication by passageways with a spring brake release valve, a pressure protection valve, and a proportioning valve module;
- said spring brake release valve being in communication with said supply air, and being operable at a first predetermined supply air pressure to connect a port leading to said spring brake chamber from an exhaust port to said supply air,
- said pressure protection valve being in line with said supply air, said pressure protection valve being biased to open at a second predetermined pressure to connect said supply air with said proportioning valve module and with said spring brake release valve and said spring brake chamber,
- said proportioning valve module being in communication with said supply air and said reservoir by passageways, said proportioning valve module having a first mode of operation for limiting pressurization of said reservoir by said supply air during an initial charging period while providing full pressurization of said spring brake chamber by said supply air, and said proportioning valve module having a second mode of operation for providing an increase in pressurization of said reservoir and service brake chamber when said spring brake chamber has been partially pressurized with supply air.
Dependencies are inferred from the claim text.