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US 4,063,784 AGranted
Two-pressure brake control valve for airbrakes
AssigneeKnorr-Bremse GmbH
InventorPeter Pick
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AssigneeKnorr-Bremse GmbH
InventorPeter Pick
Estimating the term…
A two-pressure brake control valve has a service brake portion which is connected to a brake line, an auxiliary reservoir,an emergency reservoir and a brake cylinder. A main piston in the service brake portion is subjected to brake line pressure on one side and on its other side is subjected to pressure in the auxiliary reservoir. An auxiliary piston which has a greater sensitivity of response than the main piston is displaceable on the main piston and has one side subjected to the brake line pressure and its other side subjected to auxiliary reservoir pressure. A release acceleration valve is connected to the brake line and has an actuator in the displacement path of the auxiliary piston so as to be actuated to an open position upon movement of the auxiliary piston in the initial phase of a brake release operation. There is also a filling valve which is actuated in response to movement of the auxiliary piston to connect the emergency reservoir to the auxiliary reservoir during the release operation.
In a two-pressure brake control valve for a single stage releasing indirectly acting airbrake for railway vehicles having a service brake portion connected to a brake line, an auxiliary reservoir, an emergency reservoir and a brake cylinder, said service brake portion comprising a slidingly displaceable main piston connected to said brake line and auxiliary reservoir to be responsive to the difference in pressure between said brake line and auxiliary reservoir and displaceable in response to the difference in pressure in said brake line and auxiliary reservoir during braking and release operations, an auxiliary piston slidably displaceable in said main piston between two end positions and one side subjected to brake line pressure and the other side subjected to auxiliary reservoir pressure, said auxiliary piston having a greater sensitivity of response to pressure difference than said main piston, a release acceleration valve connected to the brake line and to the emergency reservoir, means in the displacement path of said auxiliary piston and responsive to movement of the auxiliary piston for actuating said release acceleration valve to an open position to connect said emergency reservoir to said brake line in the initial phase of a release operation, and means responsive to said actuating means for connecting said emergency reservoir to said auxiliary reservoir during the release operation.
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Controlled by two fluid pressures: with one or more auxiliary valves, for braking, releasing, filling reservoirs
Other control devices or valves characterised by definite functions: with a quick braking action, i.e. with accelerating valves actuated by…
Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other…:…
Vehicle brake control systems or parts thereof
Term ended 20 Dec 1994 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to a two-pressure brake control valve for a single stage releasing indirectly acting airbrake for railway vehicles having a service brake portion connected to a brake line, an auxiliary reservoir, an emergency reservoir and a brake cylinder, more particularly, to a release acceleration device for such a control valve.
Various forms of brake control valves have been utilized in air braking systems for railway and other vehicles. One such brake control valve comprises a two-pressure control valve for a single stage releasing indirectly acting air brake system and having a service portion and an emergency portion both of which are connected to a brake line, an auxiliary reservoir, an emergency reservoir and to at least one brake cylinder. The service brake portion is provided with a main control piston actuated by the difference between the brake line pressure and the auxiliary reservoir pressure and this piston actuates a brake accelerator having an overflow chamber in order to provide uniform and rapid application of the brakes. Also in the service brake portion is a brake valve which permits air from the auxiliary air reservoir to act upon the brake cylinder and a release valve for venting the brake cylinder. There is further provided a release acceleration valve which is actuated in response to the difference between the brake line pressure and the auxiliary reservoir pressure. The release acceleration valve in the initial phase of the brake release operation connects the emergency brake reservoir to the brake line so that this reservoir can be filled with air and during the release operation connects the emergency brake reservoir to the auxiliary brake reservoir.
Such release acceleration valves must comply with the requirement that when the reservoirs are refilled during a normal brake release operation of the brakes on the vehicles of a train, the release operation of individual brakes on a vehicle should not be started until the pressure in the brake line is built up sufficiently to secure a release of brakes in the adjacent vehicles.
Other objects and advantages of the present invention will be apparent upon reference to the accompanying description when taken in conjunction with the following drawings, which are exemplary, wherein:
FIG. 1 is a diagrammatic view, in section, of the service brake portion of the brake control valve of the present invention and showing the main control piston in its lower end position;
FIG. 1a is a portion of FIG. 1 but in enlarged scale to show the main and auxiliary pistons;
Proceeding next to the drawings wherein like reference symbols indicate the same parts throughout the various views a specific embodiment and modifications of the present invention will be described in detail.
In FIG. 1, there is shown a service brake portion 1 of a brake control valve which controls the brake functions as a single release procedure wherein a brake cylinder is completely vented during a partial increase of pressure in a brake line (L-line) 3 by means of pressure in an auxiliary air reservoir (R) 4. The left side of the service brake portion 1 is bolted to the right flange of a valve support 2 which is attached to the frame of the vehicle in a known manner. On the left flange of the valve support there is attched an emergency brake portion, which is not illustrated, which together with the service brake portion 1 constitutes the brake control valve. On the right side of the service brake portion 1 as shown in FIG. 1 there is attached a release valve portion having a rapid release valve which is not illustrated.
The emergency brake portion and the release brake portion including the rapid release valve may be known valve components that can be assembled together with the service brake portion 1 to constitute a single-release brake control valve.