US2834481A - Automatic couplers for railway and like vehicles - Google Patents

Description

May 13, 1958 ca. 0. MARSH ETAL 2,334,431

AUTOMATIC COUPLERS FOR RAILWAY AND LIKE VEHICLES Filed Nov. 8, 1955 2 Sheets-Sheet 1 May 13, 1958 G. c: MARSH ETAL 2,834,481

AUTOMATIC COUPLERS FOR RAILWAY AND LIKE VEHICLES Filed Nov. 8, 1955 2 Sheets-Sheet 2 Unite a States Patent AUTOMATIC COUPLERS FOR RAILWAY AND LIKE VEHICLES Gerald Crant'on Marsh, Eramhail, Cheshire, Eric John Application November 8, 1955, Serial No. 545,709

Claims priority, application Great Britain November 16, 1954 5 Claims. (Cl. 213--76) This invention relates to automatic couplers for railway and like vehicles of the kind, hereinafter termed of the kind described, which comprises a substantially vertical face arranged to abut a corresponding substantially vertical face of a mating coupler and in which, when two couplers are properly coupled they are locked together in such a way that relative movement between the two abutting faces is substantially prevented.

When a train of railway vehicles is equipped with fluid pressure operated brakes, a so-called train pipe, or brake pipe, extends the length of the train connecting with the braking apparatus on each of the vehicles, and the brakes are automatically applied and released by varying the fluid pressure obtaining in this train pipe in well known manner.

Couplers are known which incorporate means for automatically establishing communication between the sections of the train pipe carried by two adjacent vehicles when the two are coupled together. When vehicles are uncoupled it is desirable to have some means for preventing extraneous dirt and moisture from entering the train ipe to the detriment of the braking apparatus and its operation.

One of the requirements of an automatic fluid pressure operated (vacuum or compressed air) braking system for railway trains is that the breaking away of one or more vehicles from the rest of the train shall automatically cause an application of the brakes, so that any device which prevents the ingress of extraneous dirt and moisture must also permit the relatively unrestricted flow of air into or out of the train pipe (according to whether the brakes are vacuum or compressed air operated) in the event of such a break away, and it is an object of this invention to provide such a device having this feature.

A further object of the invention is to provide a train rpipe'connecting device which may be conveniently secured in position and removed therefrom as a single unit without the use of spanners or other tools.

Accordingly the invention provides in an automatic coupler of the kind described, a detachable train pipe connecting unit comprising a hollow body defining therein a chamber open at one end and closed at the other and having a port for permanent communication between said chamber and the train pipe, valve device for opening and closing the open end of said chamber, a resilient sealing member'around said open end and located for engagement with a corresponding sealing member of a mating coupler to form a seal when the two couplers are coupled together and means for the automatic opening of said valve device by the coupling together of the two couplers, said valve device comprising a valve member which is biassed by a spring towards its closed position and which is opened by the flow of air between the train pipe and atmosphere through said chamber whentwo couplers are accidentally parted and remains open until the difference in pressure between the train pipe and atmosphere is reduced to a value no longer sufficient to hold the valve member open against the action of said spring.

Preferably the longitudinal axis of the train pipe connecting unit is normal to the plane of the vertical face of the coupler, said unit being slid'able axially ina housing formed in or secured to the coupler, and being held therein by a spring, when the coupler is not coupled, in such a position that said open end projects slightly beyond said plane, whereby the coupling together of two couplers causes the spring to be further stressed to provide sealing pressure between the two sealing members.

The housing of the train pipe connecting unit may be a cylindrical bore within which the unit is retained by a so-called bayonet type of fixing, an L shaped slot being formed in the wall of the housing and engaged by a radially projecting rigid pipe, the unit being held in position by a spring which is stressed during the insertion of the unit into the housing. The pipe is in communication with the chamber and may be connected to the train pipe by a flexible hose.

The valve device may comprise an inner member axially slidable in said chamber having a stem and a valve member on said stem biassed by a sprin into engagement with an annular seat formed by an inwardly projecting shoulder of the hollow body at its open end, thereby to interrupt communication between said chamber and the atmosphere and said inner member projecting slightly through said coupling face for engagement by the corresponding inner member of a mating coupler, whereby the coupling of two couplers forces the valve member off its seat.

For use with compressed air braking systems the valve device of the train pipe connecting unit may comprise a main valve member slidably mounted on the stern of the inner member and seating on the. annular seat between the said chamber and the atmosphere said main valve member having a port or ports therethrough which are normally closed by a spring biassed auxiliary valve member formed on the stem and which are opened automatically when the coupler is uncoupled and the action of the biasing spring is overcome by the fluid pressure in the chamber when the latter exceeds the atmospheric pressure by a predetermined amount.

The hollow body may be closed at one end by a piston slidable in said chamber, the arrangement being such that the rearwardly directed thrust due to the pressure of compressed air Within the train pipe connecting unit is taken by the piston and applied to the housing in such a manner that the hollow body of said unit is relieved of said thrust andthe seal between the units of two coupled couplers is maintained.

Although concerned primarily with the connection of the sections of train pipe carried by adjacent vehicles, the invention is also applicable to the connection of the steam pi es carried by the vehicles for heating purposes. Since the steam pipes are charged with steam at a pressure above that of the atmosphere, a steam pipe connecting unit in accordance with the invention is provided, in the same way as the unit foruse with compressed air braking systems, with a piston slidable in the hollow body and closing one end thereof, the piston being disposed to be engageable with the housing Within which the unit is accommodated in the coupler, or with a part in fixed relationship with that housing, in order that the unit may be relieved of the rearwardly directed thrust due to the pressure of steam in the unit. The valve device in the steam pipe connecting unit is similar to that in the unit for use with vacuum braking systems in that the valve member is biassed by a spring acting thereon in the direction from the closed end to the open end of the hollow body so as to close the valve member on a valve seat at the open end of the body whenever the coupler is uncoupled or accidentally parted. The possible danger of steam escaping under pressure is therefore prevented and no immediate loss of heating occurs in the vehicles in the event of two couplers parting. The valve device also ensures that no dirt enters the steam pipe.

The invention will be further described by way of example with'reference to the accompanying drawings in which:

Figure 1 is a sketch showing a preferred arrangement of a detachable pipe connecting unit in an automatic coupler of the kind described, other parts apertaining to the installation of the coupler in a vehicle being shown to illustrate the general arrangement,

Figure 2 illustrates in section a form of pipe connecting unit designed in accordance with the invention for use in connecting the sections of train pipe of a vacuum operated braking systeni; this design being also fundamentally suited to the connection of the steam pipes, and

Figure 3 illustrates, also in section, a further form of pipe connecting unit designed in accordance with the invention for use with compressed air braking systems.

The coupler shown in Figure l is of usual construc tion as regards coupling features, being formed with a substantially vertical face presenting a rounded nose 11 and a recess to accommodate the nose of a mating coupler. Angular movement of the coupler about the pivot 12 fixed on the vehicle is limited to the length of a horizontal slot which is defined by structure 13 and through which the coupler passes. The head of the coupler is extended downwardly to provide a housing 14 for the i train pipe connecting unit indicated generally 15. The housing is split longitudinally at the bottom and provided with lugs 16 on either side of the split. A bolt 17 retained in the lugs 16 prevents withdrawal of the connecting unit by abutment with a pipe connecting piece 13, as will be more apparent from Figure 2. Joining the connecting piece 18 with the section of train pipe 19 carried by the vehicle is a length of flexible hose 20. An isolating cock 21 is introduced into the train pipe section 19 adjacent each end thereof, the cock being adjustable to the on or off position by an arm 22.

The pipe connecting unit is slidable in a cylindrical bore in the housing 14, the axis of the bore being normal to the plane of the vertical face of the coupler and so positioned in that face that, whenever the coupler is coupled to another mating coupler the two train pipe connecting units are coaxial.

Referring now to Figure 2, the train pipe connecting unit comprises an outer hollow cylindrical body 23 open at one end 24 and closed at the other end by a screw threaded cap 25. The wall of the hollow body 23 is pierced by a port 26 which communicates with the connecting piece 18 formed, in this case, integral with the body. The pressure required to hold the connecting piece 18 abutting the bolt 17 is provided by a helical spring 27 interposed in compression between the cap and the rear wall of the housing 14. The exposed front face at the open end 24 of the hollow body is provided with a resilient sealing member in the form of a frustroconical lip 28 of resilient material such as rubber, which lip is disposed encircling the opening in the end 24 to engage a similar lip of a mating unit, when two couplers are coupled together, to forma fluid tight seal.

Slidably mounted in the hollow body 23 and, in the uncoupled condition of the coupler, extending axially slightly beyond the front face of the body is an inner member having a valve member 29 and a hollow stem 30 which engages telescopically a tubular extension 31 of the cap 25. The hollow stem 30 contains a helical spring 32 extending between a seat formed in the valve member 29 and a seat 33 formed in the tubular extension 31, whereby the valve member is biassed towards the open end 24 of the hollow body and, when the coupler is not coupled, is retained in seating engagement with an inwardly projecting shoulder formed on the body at 4 the end 24 to prevent the ingress of dirt and moisture into the train pipe.

When two couplers are coupled together, the front face of the hollow body and the inner member are engaged by the corresponding parts of the unit in the mating coupler, the springs 27 being further compressed so that the sealing lips 28 are pressed together by these springs to form a fluid tight seal. Engagement of the valve members 29 causes them to be forced inwards, further compressing their respective biassing springs 32 and opening the valves to establish communication between the two units and thus between the two sections of train pipe carried by the two coupled vehicles.

Should the two couplers part when the normal degree of vacuum pertains in the train pipe the train pipe connecting units become disengaged and atmospheric air rushes in through the open end of the hollow body and the pressure thereof, acting on the exposed surfaces of the valve member, holds the latter off its seat until the degree of vacuum in the train pipe is reduced to a value at which the pressure difference between the two sides of the valve device is insufficient to hold the valve open against the action of the spring 32. When this occurs the valve closes and prevents the entry of dirt and moisture into the train pipe. It will thus be seen that the breaking apart of a pair of couplers results in the destruction of the vacuum in the train pipe and consequently an application of the brakes, followed by the sealing of the train pipe against the entry of extraneous dirt and moisture.

In the form of train pipe connecting unit illustrated in Figure 3 for use with compressed air braking systems, the inner member comprises a main valve member 40 and an auxiliary valve member 41. The main valve member 40, as does the valve member 29 of the previously described form of unit, seats on an inwardly projecting shoulder at the open end of the hollow body, and is part of a sleeve 42 slidably mounted on a stem 43 of the inner member, the auxiliary valve member 41 being formed on the stem. The main valve member 40 is annular in shape to provide a port with a seating surface 40a for the auxiliary valve member 41. Located immediately behind the main valve member 40 are ports 44 in the sleeve 42, the stem 43, which is not hollow in this case, being of reduced section in the region of these ports so that a rearwardly directed face of the auxiliary valve member is exposed to the pressure within the hollow body.

The auxiliary valve member 41 projects beyond the open end of the hollow body and the seating surface 40a is of conical shape diverging outwards from the hollow body so that the thrust applied to the inner member when the auxiliary valve member encounters the corresponding member of a mating coupler and the two couplers are coupled together is transmitted through the auxiliary valve member to the main valve member, thereby opening the main valve against the action thereon of a return spring 45. The auxiliary valve is normally maintained closed by a biassing spring 46 extending between a shoulder on the sleeve 42 and a collar 47 fixed on the stem 43.

The hollow body is composed of four sections: a front end section 52 defining the open end of the body and carrying the resilient sealing member formed, in this case, in the manner of a pad, a tubular rear end section 53, an intermediate cylindrical section 54 to the ends of which the end sections 52 and 53 are fixed by screw threads, and a bush 55 fitted within the intermediate section 54. The bush 55 is formed with a boss or spider 56 acting as a guide and support for the sleeve 42 of the main valve member and affords a suitable sliding surface for a cup-shaped piston 48 which closes the rear end of the hollow body and is slidable therein, escape of compressed air past the piston being prevented by the provision of at least one packing ring such as that indicated at 49. A stem 50 of the piston 4'8 projects into the tubular end section 53 and is provided with an axially extending blind bore 51 within which the stem 43 of the inner member is guided.

A spring 57 is housed by the tubular end section 53 between a small internal flange 58 formed thereon and a plate 59 there being. a retaining ring 60 adjacent the rear end of the section 53 to render the spring and plate captive within that section when the hollow body is removed from its housing.

In Figure 3, the unit is shown retained in the housing by a bayonet type of fixing, the wall of the housing having formed therein an L-shaped slot of which the leg portion appearing in the figure is designated 61, the other leg portion of the slot being open at the outer edge of the housing to allow of the insertion into the leg portion 61 of the rigid pipe connecting piece 18 mounted, in this case, radially of the hollow body. When the unit is installed in the housing, the plate 59 is positioned clear of the retaining ring 60 by engagemnt with an appropriately disposed abutment 62 formed in the housing so that the spring 57 then acts to push the unit forward in relation to the housing and provides the pressure necessary to hold the connecting piece 18 against the side of the slot 61. When the coupler containing the unit is uncoupled, the unit is so positioned by the connecting piece 18 in the slot 61 that the front end section 52 of the hollow body projects slightly beyond the vertical face of the coupler and the stem 50 of the piston 48 is held separated from the plate 59 by a small gap due to abutment of the piston, under the action of the spring 45 against a shoulder 63 of the rear end section 53 of the hollow body.

If now the coupler is coupled to another mating coupler, the unit is forced rearwards into the bore of the housing by an amount which is greater than the gap between the piston stem 50 and the plate 59 so that the two engage. Thus, when the train pipe is charged with compressed air, the rearwardly directed thrust, due to the pressure building up in the unit, tending to separate termined value the auxiliary valve member 41 is closed.

by its biassing spring 46 and the two valve members form a seal against the entry of dirt and moisture.

It will be appreciated that the isolating cock denoted 21 in Figure 1 is provided in order to close the train pipe at the end of a vehicle from which another is to be uncoupled, so that the uncoupling does not result in the venting of the train pipe to atmosphere.

A unit similar to that shown in Figure 2 maybe installed in a coupler for the purpose of making the connection between the steam pipes of adjacent vehicles, but is modified to include the feature, described with reference to Figure 3, for relieving the unit of the rearwardly directed thrust due to the pressure of the steam. Thus, the cap 25 may be arranged to slide in the hollow body 23 instead of being fixed therein and be extended rearwardly to abut the rear wall of the housing, the spring 27 being arranged to bear directly against the hollow body. Two units, one for train pipe connection and the other for steam pipe connection, may be installed in the same coupler, the relative disposition of the units being such as to ensure their connection with the corresponding units of a mating coupler.

Having thus described our invention what we claim is:

1. In an automatic coupler of the kind having a substantially vertical face arranged to abut a corresponding vertical face of a mating coupler and to be locked in coupler and closed at the other end and having a port to establish permanent communication between said chamber and the train pipe, a valve device for opening and closing the open end of said chamber, a resilient sealing member extending around said open end and located to be engageable with the corresponding member of a mating coupler, a spring positioning said body, when the coupler is not coupled, with said open end projecting slightly beyond said plane so that the coupling together of two couplers causes said spring to be further stressed to provide sealing pressure between the sealing members, and means for the automatic opening of said valve device by the coupling together of the two couplers, said valve device comprising a valve member which is biassed by a spring towards its closed position and which is opened by the flow of air between the train pipe and atmosphere through said chamber when two couplers are accidentally parted and remains open until the difference in pressure between the train pipe and atmosphere is re duced to a value no longer sufilcient to hold the valve member open against the action of said spring.

2. In an automatic coupler of the kind having a substantially vertical face arranged to abut a corresponding vertical face of a mating coupler and to be locked in abutting relationship therewith, a detachable train pipe connecting unit comprising a hollow body slidable axially within the coupler in a direction normal to the plane of said vertical face, said body defining therein a chamber open at the end thereof facing outwards of the coupler and closed at the other end and having a port to establish permanent communication between said chamher and the train pipe, a valve device for opening and closing the open end of said chamber, a resilient sealing member extending around said open end and located to be engageable with the corresponding member of a mating coupler a spring positioning said body, when the coupler is not coupled, with said open end projecting slightly beyond said plane so that the coupling together of two couplers causes said spring to be further stressed to provide sealing pressure between the sealing members, and means for the automatic opening of said valve device by the coupling together of the two couplers, said valve device comprising an inner member having a stem, a main valve member slidably mounted on said stem, a return spring biassing said main valve member towards its closed position, an annular valve seat for said main valve member formed at said open end, an auxiliary valve member formed on said stem, and a spring biassing said auxiliary valve member towards a position in which it closes at least one port through said main valve member, said port being opened when the coupler is uncoupled and the air pressure in said chamber acting on said auxiliary valve member exceeds the atmospheric pressure by an amount suflicient to overcome the action of the spring biassing said auxiliary valve member.

3. In an automatic coupler of the kind having a substantially vertical face arranged to abut a corresponding vertical face of a mating coupler and to be locked in abutting relationship therewith, a detachable train pipe connecting unit adapted for use with a braking system operated by compressed air and comprising a hollow body slidable axially within a housing of the coupler in a direction normal to the plane of said vertical face and having a port to establish permanent communication between the interior of said body and the train pipe, a piston slidable within said body to close one end thereof and leave open the other end facing outwardly of the coupler, an inner member having a stern, a main valve member slidable on said stern, a return spring biassing said main valve member towards its closed position, an annular valve seat for said main valve member formed at the open end of said body, an auxiliary valve member formed on said stem and biassed by a spring towards a position in which it closes at least one port through said rnain valve member, a resilient sealing member extending around said open end and located to be engageable with the corresponding member of a mating coupler, a spring urging said body outwardly of said housing, and stop means by which, when the coupler is not coupled, said body is held projecting slightly beyond said plane whereby said spring is further stressed by the coupling of the coupler to another coupler to provide sealing pressure between the sealing members, the arrangement being such that, when both said valve members are in closed position, said inner member projects suificiently beyond said open end to be engageable with the corresponding member of a mating coupler and thrust applied to said inner member when coupling takes place is transmitted through said auxiliary valve member to said main valve member to lift same from its seat, said piston is disposed to be engageable with said housing to relieve said body of rearwardly directed thrust due to compressed air contained thereon, and said port through said main valve member is opened when the coupler is uncoupled and the air pressure within said body acting on said auxiliary valve member exceeds atmospheric pressure by a predetermined amount sufficient to overcome the action of the spring biassing said auxiliary valve member.

4. In an automatic coupler of the kind having a substantially vertical face arranged to abut a corresponding vertical face of a mating coupler and to be locked in abutting relationship therewith, a detachable pipe connecting unit slidably received within a housing in the coupler, said housing defining an open-ended slot, a rigid pipe connecting piece extending laterally of said unit for connection of the interior of said unit to a pipe carried by the vehicle to which the coupler is attached, said pipe connecting piece being adapted to pass into said slot, a spring urging said unit in a direction outwardly of said housing, stop means in'fixed relationship with said housing and engageable with said pipe connecting piece to hold said unit against the action of said spring in such a position that, when the coupler is not coupled, the forward end of said 'unit projects slightly beyond said vertical face, and, sealing means at the forward end of said unit and located for engagement with the corresponding means of a mating coupler, whereby the coupling together of two couplers causes said spring to be further stressed to provide sealing pressure between the sealing means of the couplers.

5. In an automatic coupler of the kind having a substantially vertical face arranged to abut a corresponding vertical face of a mating coupler and to be locked in abutting relationship therewith, a detachable pipe connecting unit slidably received within a cylindrical bore of a housing of the coupler, a rigid pipe connecting piece projecting radially from said unit for connection of the interior of said unit to a pipe carried by the vehicle to which the coupler is attached, a spring urging said unit in a direction outwardly of said housing, and sealing means at the forward end of said unit and located for engagement with the corresponding means of a mating coupler, the wall of said housing defining an L-shaped slot into which said pipe connection is adapted to pass in the manner of a bayonet type of fixing and said unit being held by said fixing against the action of said spring in such a position that, when the coupler is not coupled, the forward end of said unit projects slightly beyond said vertical face whereby the coupling together of two couplers causes said spring to be further stressed to provide sealing pressure between the sealing means of the couplers.

References Cited in the file of this patent UNITED STATES PATENTS 918,230 Ward Apr. 13, 1909 1,795,147 Schleich et a1 Mar. 3, 1931 1,877,924 Mackin Sept. 20, 1932 2,677,472 Larsson May 4, 1954

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