A quick acting three-way valve that operates a poppet with a lost motion connection. A sleeve is sealed through the diaphragm. A solid or hollow sleeve may be employed with a hollow or solid poppet, respectively. If either the sleeve or the poppet is hollow, the other may or may not be, as desired. An exhaust port is provided in communication with either one or both of the hollow interiors of the sleeve and poppet, the exhaust port being provided through the valve body.
BACKGROUND OF THE INVENTION
This application is a division of copending application Ser. No. 461,743 filed Apr. 17, 1974, for COMBINATION VALVE, the said copending application Ser. No. 461,743 being a division of copending application Ser. No. 359,653 filed May 14, 1973 for COMBINATION VALVE, the said copending application Ser. No. 359,653 being a continuation-in-part of abandoned application Ser. No. 217,539 filed Jan. 13, 1972 for DIAPHRAGM VALVE AND COMPONENTS THEREOF. The benefit of the filing dates of all of the aforesaid applications is hereby claimed for this application.
A braking system for railroad freight trains and a novel relay valve for use in the system are disclosed. The relay valve permits the brake system to be configured so that the requirement for expensive control valves is minimized. The novel relay valve is interposed between the control valve and a number of brake cylinders. Upon a signal from the control valve, the relay valve delivers brake air to the cylinders from a pre-charged reservoir or other source. The novel relay valve includes primary and secondary flow valves to cause air to be delivered to the brakes in a controlled manner. An exhaust valve arrangement in the relay valve permits the brakes to be released.
A valve arrangement has a housing in which are arranged an electromagnetically actuatable pilot valve controlling a differential pressure and a main valve actuatable by the differential pressure, the closure member of the main valve permitting a connection to be established between an outlet port and, alternatively, a first or a second inlet port. In order to keep the overall length of the valve arrangement as small as possible, the present invention provides a joint axis (29) of the pilot valve (5) and of the electromagnet (6) actuating the pilot valve (5) which is perpendicular to the axis (30) of the main valve (7) in a plane that is radially offset relative to the axis (30). In the inactive position, both compartments (23, 24) are exposed to the higher pneumatic pressure.
An electrically actuated relay valve or adaptive braking modulator for a vehicle fluid pressure braking system includes a housing having a fluid pressure inlet, a pair of vents communicating with the ambient atmosphere, and a brake application effecting mechanism. The inlet communicates with a chamber defined within the modulator, amd this chamber is in turn communicated to the brake application effecting mechanism. An electrically actuated valve controls communication from the inlet into the chamber, and is shiftable from a first condition permitting substantially uninhibited communication from the inlet to the chamber to a second condition communicating the chamber to one of the vents when an incipient skidding condition is detected. A pressure differential responsive valve element controls communication between the chamber, the brake application effecting mechanism, and the other vent. When the pressure level in the brake application effecting mechanism is greater than the pressure level in the chamber, the pressure differential responsive valve element communicates the brake application effecting mechanism to the other vent. However, when the electrically actuated valve is not actuated during normal braking, the pressure differential responsive valve element prevents communication to the other vent and permits uninhibited communication between the chamber and the brake application effecting mechanism. This arrangement substantially improves the response time of the adaptive braking modulator.
An air hoist having a reversely rotatable drum adapted to have an elongated flexible load-carrying element, such as a cable, wound onto or off of the drum to permit lifting or lowering of a load. The drum also serves as a reciprocating cylinder and is axially slidably disposed in sealed engagement with an internal piston which, while it rotates with the drum, is axially restrained. A fluid pressure chamber is formed between the end wall of the drum and the piston so that the pressure fluid which is supplied to or discharged from this chamber controls the axial displacement of the drum. A ball-screw arrangement coacts between the drum and a stationary support so as to cause rotation of the drum in response to axial movement thereof, whereby the drum undergoes a helical-type motion during winding or unwinding of the load-carrying element. A control device is associated with the hoist for controlling the flow of pressure fluid to or from the pressure chamber.
A vacuum-operated brake power booster is provided having a movable wall which is sealed off relative to the vacuum housing and a control valve body which is slidable jointly with the movable wall. A hollow cylinder-shaped expanded plastic ring is arranged in the annular clearance between the neck portion of the pedal side housing shell and the collar of the diaphragm, which collar sealingly surrounds the control valve body. The expanded plastic ring effects the air flow during brake operation such that the air flow, enters the annular clearance through the duct extending in a radial direction within the control valve body and is suitably deflected and cushioned so that no noises arise at this point. In the same manner and simultaneously, vibrations, especially those of the neck portion of the housing shell of the vacuum housing, are suppressed, since the expanded plastic ring adheres to the inside wall of the housing shell.
