US2595466A

US2595466A - Brake pipe vent control

Info

Publication number: US2595466A
Application number: US75824A
Authority: US
Inventors: Keller Siegfried
Original assignee: Werkzeugmaschinenfabrik Oerlikon Buhrle AG
Current assignee: Rheinmetall Air Defence AG
Priority date: 1948-02-16
Filing date: 1949-02-11
Publication date: 1952-05-06
Anticipated expiration: 1969-05-06
Also published as: FR70359E; GB661572A; FR980975A; DE802878C; ES187041A1; FR62619E; NL81175C

Description

May 6, 1952 5, KELLER 2,595,466

BRAKE PIPE VENT CONTROL Filed Feb. 11, 1949 INVENTQR Siegfried Keller AT ORNE'JS Patented May 6, 1952 2,595,466 BRAKE PIPE VENT CONTROL Siegfried Keller, Effretikon, Switzerland, assignor to Machine Tool Works Oerlikon, Administration Company, Zurich-Oerlikcn, Switzerland, a

company of Switzerland Application February 11, 1949, Serial No. 75,824

In Switzerland February 16, 1948 5 Claims. 1

In accordance with the international regula tions governing brakes on goods trains, the control valve of each wagon braked should, when the indirect-acting pneumatic brakes are applied, automatically produce a specific decrease in pressure in the continuous brake-line with a view to achieving a quick response of the brakes throughout the train.

In the existing types of control valves this is generally achieved by an arrangement whereby a so-called accelerator responds to the decrease in pressure in the continuous brake-line initiated from the drivers cabin, said accelerator opening a valve by means of which compressed air in the brake-line can suddenly expand into a specific additional volume. This produces a specific rapid drop in pressure in the brake-line, which drop is propagated in like manner through all the control valves to the end of the train. Such accelerators may come into action only when the brakes are first applied and must remain inoperative during the continued application or release of the brakes. As the above-mentioned additional volume is in most cases comprised within the control valve casting, it involves an increase in the dimensions and weight of this appliance.

The invention relates to a device for indirectacting pneumatic brakes for achieving a sudden tapping of the pressure medium in the continuous brake-line at the moment when the brakes are first applied, said device comprising a rocker which is controlled by a piston actuated by the drop in pressure in the brake-line and momentarily opens a valve leading from the brake-line to the atmosphere, being thereupon tipped up by the movement of said piston to such an extent that the operated valve can return to'its position of closure, said rocker being, after the brakes have been initially applied, held in its tipped-up position, independently of the further movements of the piston operating it, by a looking member controlled by the brake cylinder pressure, until such time as the pressure in the brake cylinder has dropped to a pre-determined minimum value upon the release of the brake.

In the enclosed drawing the object of the invention is diagrammatically represented; in said drawing:

I designates a known type of control valve for indirect-acting pneumatic brakes, II the compressed air reservoir, III the brake cylinder, IV the rocker accelerator, V the locking member.

The piston 55 of a known type of indirectacting control valve I connected to the continw ous brake-line I slides in a housing it with which; 1

the brake-line I is connected, in response to a decrease in pressure in the brake-line I effected from the drivers cabin with a view to app y the brakes, to the left as a result of the throttling effect of the duct 2. The guide bush 4, in which the rocker 5 (comprising two arms l1, l8 forming a right angle) is pivotally mounted at 6, is thereby likewise displaced out of a rest position to the left in opposition to the slight pressure exerted by the spring 7.

The arm ll of the rocker 5 which, in the rest position shown in the drawing is in alignment with the tappet 8 of the accelerator valve 9, engages this tap'pet and opens the valve against the influence of a spring H5 pressing the valve on its seat. Thus the brake line I is connected with the atmosphere through the housing l5. Owing to the sudden escape of compressed air the piston 3 is impelled still further to the left to a working position. Shortly before reaching this position the arm 58 of the rocker 5 bears against the edge H} of the housing I5, whereupon it is pivoted about the pin 6. At this moment the tappet 8 of the valve 9 is released and the latter is closed again by the spring It.

To prevent the accelerator from coming into action again in the course of the continued application or the release of the brakes, the guide sleeve i is arrested by the plunger II in the groove [2 as soon as a specific brake cylinder pressure on the piston Hi corresponding to the first pressure stage is produced via the conduit I3. Only when, upon release of the brakes-- which is performed by increasing the pressure in the brake pipe l-the brake cylinder pressure has dropped below that of the first pressure stage, can the brake-line pressure acting on the plunger ll overcome the brake cylinder pressure exerted on the piston 14, whereupon the guide-sleeve t is released and slides back to its initial position under the pressure exerted by the spring I, to operate again, in the manner described, when the brakes are again applied.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. In a pneumatic brake, in combination with a brake line, a brake cylinder and a compressed air reservoir, an accelerator valve having a valve seat, a movable valve body and a spring pressing said valve body against said valve seat; a control valve comprising a movable pressure-actuated piston, a cylinder containing said piston and u-havins, o da o ne ed w h-sai brake n and the other side connected withvsaidcompressed air reservoir, whereby said piston is actuated by difference in pressure between said brake line and said compressed air reservoir, a casing communicating with said cylinder, a rocker, a bush movable along with said piston and pivotally supporting said rocker, said rocker being movable along with said piston in the direction of movement of said valve body to open said accelerator valve against the pressure of said spring when said piston is moved, said casing connecting said brake line with said accelerator valve, said casing having a stop engaging a part of said rocker during movement of said piston and moving said rocker away from said valve body, whereupon the valve body is closed by said spring, a movable locking member locking said bush to hold said rocker in its position away from said valve body,

and means connected with said locking member and said brake cylinderand actuating said looking member by pressure in the brake cylinder to lock said rocker.

2. In a pneumaticbrake having a brake line, in combination, a casing connected with the brake line, a pistonmovable Within said casing and having one side subjected to pressure in said brake line, a compressed air reservoir connected with said casing and supplying compressed air to the other side of said piston to normally balance said piston, whereby said piston is moved when pressure drops in said brake line,,a valve in said casing for connecting said one side of the piston with the atmosphere and having a valve seat, a valve body and resilient means pressing said valve body against said valve seat to maintain said valve normally closed, a member movable along with the piston from a rest position to a working position, said member engaging said valve body during this movement and opening the valve against the action of said resilient means to vent air from said brake line, said casing comprising a member engaging the first-mentioned member during the movement of the piston and causing the first-mentioned member to disengage from said valve body, whereupon said valve is closed by said resilient means and the venting of air from said brake line is interrupted.

3. In a pneumatic brake having a brake line. in combination, a casing connected with the brake line, a piston movable within said casing and having one side subjected to pressure in said brake line, a compressed air reservoir connected with said casing and supplying compressed air to the other side of said piston to normally balance said piston, whereby said .piston is moved when pressure drops in said brake line, a valve in said casing for connecting said one side of the piston with the atmosphere and having a valve seat, a valve body and resilient means pressing said valve body against said valve seat to maintain said valve normally closed, a member movable along with said piston from a rest position to a working position, said member engaging said valve body during this movement and opening the valve against the action of said resilient means to vent air from .said brake line, said casing comprising a member which is out of engagement with the first-mentioned member in the rest position of the latter and which engages the first-mentioned member during the movement of the piston to disengage the firstmentioned member from said valve body, whereupon said valve is closed by said .resilient means and the venting of air. fromsaidbrakelineis interrupted.

4. In a pneumatic brake having a brake line, in combination, a casing connected with the brake line, a piston movable within said casing and having one side subjected to pressure in said brake line, a compressed air reservoir connected with said casing and supplying compressed air to the other side of said piston to normally balance said piston, whereby said piston is moved when pressure drops in ,said brake line, a valve in said casing for connecting said one side of the piston with the atmosphere and having a valve seat, a. valve body and resilient means pressing said valve body against said valve seat to maintain said valve normally closed, a guide bush located in said casing and movable by said piston from a rest position to a working position, a rocker mounted upon said guide bush and movable along with said guide bush as well as transverse- 1y thereto, said rocker engaging said valve body during the movement to a working position and opening the valve against the action of said resilient means to vent air from said brake line, said casing comprising, a stop engaging said rocker during the movement of the piston and causing the rocker close to the end of this movement to move transversely to the guide bush and thereby become disengaged from said valve body, whereupon said valve is closed by said resilient means and the venting of air from said brake line is interrupted.

5. In a pneumatic brake having a brake line and a brake cylinder, in combination, a casing connected with the brake line, a piston movable within said casing and having one side subjected to pressure in said brake line, a compressed air reservoir connected with said casing and supplying compressed air to the other side of said piston to normally balance said piston, whereby said piston is moved when pressure drops in said brake line, a valve in said casing for connecting said one side of the piston with the atmosphere and having a valve seat, a valve body and resilient means pressing said valve body against said valve seat to maintain said valve normally closed, a member movable along with the piston from a rest position to a working position, said member having means engaging said valve body during this movement and opening the valve against the action of said resilient means to vent air from said brake line, said casing comprising a member engaging said means during the movement of the piston and causing the means to disengage from said valve body, a locking device for locking said first-mentioned member in said working position, and pneumatic means connected with said locking device and said brake cylinder and actuating said locking device When-said brake cylinder is charged.

SIEGFRIED KELLER.

REFERENCES CITED The following references are of record in the file of this patent: