A control valve for use in a dual or split braking system which has a proportioning valve therein generally operable to proportion the fluid pressure in one of the systems. The control valve is provided with a shuttle or warning piston movable from a normally centered position to opposed translated positions in response to a predetermined differential between the separate supplied fluid pressures in said systems acting thereon.Plug Valves A by-pass passage is provided in the control valve connected in by-pass relation with the proportioning valve, and a valve member is normally urged toward a position closing said by-pass passage.Water Pump Control Valves A lost motion connection is defined between the shuttle piston and valve member wherein said valve member is moved to a position opening the by-pass passage permitting the flow of one of the supplied fluid pressures therethrough in by-pass relation with the proportioning valve to obviate the proportioning function thereof upon the movement of the shuttle piston to one of its translated positions.GATE VALVES It is also contemplated that the control valve can include the proportioning valve. A control valve comprising a housing having a bore therein, a pair of spaced inlet ports for subjection to separate substantially equal fluid pressures and connected with said bore, piston means movable in said bore between said inlet ports including a pair of opposed end portions respectively subjected to the fluid pressures at said inlet ports for comparing the magnitudes thereof, said piston means being movable from a normally centered position in said bore toward opposed translated positions therein in response to the fluid pressure at one of said inlet ports acting on one of said end portions in the event of the failure of the fluid pressure at the other of said inlet ports acting on the other of said end portions, an outlet port in said housing, said one inlet port being spaced between said outlet port and said piston means, a passage in said housing connected between said outlet port and said one inlet port, a valve seat within said bore about said passage and facing said one end portion, valve means within said bore on said one end portion and movable between a normal operative position urged into engagement with said valve seat to close said passage interrupting pressure fluid communication between said one inlet port and said outlet port and a disabled position disengaged from said valve seat to open said passage and establish open pressure fluid communication therethrough between said one inlet port and said outlet port, and said valve means defining a lost motion connection with said one end portion when said piston means is in its centered position, said piston means being movable toward one of its opposed translated positions through said lost motion connection to initially drivingly engage said one end portion with said valve means and thereafter concertedly move said valve means toward its disabled position upon the failure of the fluid pressure at said other inlet port.

MORE NEWS

2012-02-01

Back