US1387035A - Continuous automatic fluid-pressure brake for railway and like vehicles - Google Patents

Description

A. M. BELL. CONTINUOUS AUTOMATIC FLUID PRESSURE BRAKE FOR RAILWAY AND LIKE VEHICLES.

APPLICATION FILED JUNE 28, I919. 1,387,035. P nted Aug- 9, 1921.

2 SHEETS-SHEET l.

A M. BELL.

CONTINUOUS AUTOMATIC FLUSD PRESSURE BRAKE FOR RAILWAY AND LIKE VEHICLES.

V APPLICATION FILED JUNE 28. I919- 1,387,Q35 Patented Aug. 9, 1921.

2 SHEETS-SHEET 2.

WESTMINSTER, LONDON, ENGLAND; a FIRM colv'srs'rnve or JoiiN CHAR ES T ap ea] ARTHUR Mormon BELL, or BOMBAY, INDIA; ASSIGNOR To TAITE a citation, or

TAITE, FREDERICK grocntviv DAVIS, AunsnorrR-EY cnARLEsBa INnLEY'TArrE.

ooNTnvUoUs AnToian'r o' FLUID-PRESSURE BRAKE FOR RAILWAY AND LIKE VEHICLES.-

1I387I35I Specification of Letters ratiit. Patented Aug. 9,1921.

Application filed June 28,

7 Vehicles, of which the followingis aspecifi cation. I I

This invention relates to continuous automatlc fluid-pressure ,brake apparatus for I railway and like trains (more particularly goods trains) wherein, for the purpose of enabling the potential brake-power of a vehicle to be definitelyadjusted to meet the requirements arising from either the loaded orthe empty condition as' the case may be, such vehicle is provided with a su'pplemen: tary brake-cylinder whereof the piston is adapted to actuate the brake-shaft of the vehicle concurrently with the piston of the primary or normally-operative brake-cylinder, and a device (hereinafter termed a control-valve) whereby to effect on the one hand the manual throwing into potential operation, and on the-other hand the automatic cutting-out of -said supplementary brakecylinder according as it 'is required to exchange the braking capabilities of the vehicle from those proper to an empty to those proper to a loaded vehicle, or vice versa.

The primary object of the. present invention is to provide an improved construction of control-valvefor use in combination with the supplementary brake-cylinder and with a supplementary fluid-pressure reservoir and other necessary devices andconnectlons for enabling the requisite supply of fluid under pressure (hereinafter referred to as; compressed air) tobe furnish mentary brake-cylinder. I,

, The improved control-valve is interposed ina connection between the train-pipe and the triple-valve of the supplementary fairreservoir and brake-cylinder of the vehicle, and comprises the control-valve itself (prop-- erly so-called) which, onthe one hand, constantly tends under spring-action to assume the closed position wherein it cuts off com munication betweenthe train-pipe and the supplementary air-reservoir. and brake+cylinder, and which, on the, other hand, is

. with theed to the s upple- 1919. Serial no. '307,2eo.'

adapted to be brought, by meanskof'a manually-operable cam, to the open position.

wherein, it establishes such communication and thus renders the supplementary brakecylinder brake-cylinder of the vehicle. Means are provided whereby, when pressure. exists in. the supplementary a1r-reservo1r (as during ordinary working conditions), although the control-valve still remains open, the .cam

I becomes potentially freed to spring-action'in n such. manner that, on the brakes being completely released .or allowedto leak-off (as when the vehicle is put'aside with a view to being unloaded), the cam will be automatically restored to inoperative position, thus permitting the automatic return'of the control valve itself to its closed position. 7 I In the accompanying drawings, which illustrate'one form of the improved controlvalve and parts immediately I associated therewith, Figure 1 shows the valve in the closed position, Fig. 2 shows ther same in the open position, Fig. .3 shows the valve in potentially operative in conjunction prlmary (or normally-operative) the intermediate (but still open) positionv which it assumes during ordinary working conditions when the vehicle to which it is applied 'is'being run loaded, and Fig. 4 is a diagrammatic view illustrating the relation between the improved control-valve, the train 1 pipe and the'supplementary brake-cylinder with its air reservoir and triple-valve, as

well as the primary brake-cylinder with its air-reservoir and triple-valve.- In' each figtween the train-pipe a and the air-reservoir c and between said reservoir and the brakecylinder Z). The construction of these parts and their interconnections and mode of operation are well known in the art need not be further described. I bis the supplementarybrake-cylinder, of the supplementary air-reservoir, and-d the supplementary ,ure the valve-casingis represented in; axial 'SQCtIOIL'.

triple-valve, all ofwhich are of usual; construction andadapted to operate inI-the well I 1 known manner; while the improved controlvalve is shown at e.' The connections between the supplementary brake-cylinder b and its triple-valve d, and between the latter and the supplementary air-reservoir 0, are

as usual, but the control-valve 6 serves to control the connection between the train-pipe 0; and the supplementary triple-valve d as hereinafter explained.

in the example illustrated, the control alv'e comprises a piston-valve 11 of substantially L 'orm litted to slide to-and-tro in a cylindsical casing 12 so as to alternatively open or close communication between two ports 13, 1-1 in the wall oi the casing, these ports being permanently connected, the one 13 by a pipe 15 with the traiirpipe a and the other 1 1 by a pipe 16 with the triple-valve CZ of the supplementary airreservoir 0' and brake-cylinder 5. Between the leftand end of the valx 'e-piston 11 and the adjacent endclosure 1T oi the casing 12, is interpoi-sed under compression, a spring 18 (hereinafter termed the valve-spring) constantly tending to cause the piston 11 to move toward the right so as to assume the closed position shown in Figs.

g iandewherein communication between the two ports 1'3, 1% is cut off; while the space 19 between the righthand end of the valve-piston 11 and the corresponding endclosure 20, of

the casing constitutes what may be termed a variable air-pressure chamber in the wall of which is a third port 21 in permanent communication by a pipe 22 with the supplementary air-reservoir; the force exerted upon the piston 11 in the one direction by the valve-sp 'ing 18 being less than that erted upon in the opposite direction by the air-pressure in. the space 19 when normal working pressure exists within the supplementary reservoir 0 a The piston rod 23 of the valvepiston 11 extends outward toward the right through a striding-box 21 at the end of the space .19,

and has attached to it, externally at 25, a

rod 26 which is movable to-and-tro as one with the piston 11 in a guide 27, and through a slot 28 in this rod extends a cam-bar 29 which is slidable in guides (whereof one 30 alone-is shown) transversely of the rod 26.

The cam-bar '29 constantly tends to assume the inoperative position illustrated in F igs. 1 and i underthe pressure of a spring 31 (hereinafter termed the cam-spring) in opposition to which it can be moved by hand to the fully set position shown in Fig. 2; the

spring being shown as confined between the guide 30 anda collar 32 on the cam-bar, while in Fig. 4 the cam-bar is shown as provided with a handle 7-5. T he left-hand edge of the car-bar 29 presents, for engagement with-the adjacent end 33 of the slot 28, an inclined cam-face which, when the bar is moved by hand against the spring 31 to the fully set position (ordinary atmospheric pressure being assumed to exist at this time in the chamber 19) causes displacement of the valve from the closed position shown in Figs. 1 and 4: to the open position shown substantially in Fig. 2, the cam-bar 29, on reaching the fully set position, becoming locked therein by the engagement of the end 33 of the slot 28 over a shoulder at the termination of the cam-face 34%. It will be observed that this locking is due to the action of the valve-spring 18 which, after the cam-face 34: has passed completely through the slot 28, returns the valve 11 a short distance toward the right until arrested by the cam-bar 29, beyond the shoulder 35, whereas the admission of air at w rlring pressure to the chamber 19 will, by moving the valve 11 toward the left, disengage the shoulder 35 and release the cam-bar 29 to action of its spring 31. It is obvious, however that if, on such release, the cam-bar were permitted to return immediatelv to its initial or idle position (Figs. 1 and i), there would be a possibility of the valve 11 closing, prematurely, the connection between the ports 13 and 14- as a result of e. g. shock or excessive vibration during the running of the train; Means are therefore provider for insuring that the ultimate restoration of the cam-bar 29 to itsinitial or idle position (Figs. 1 and a) shall be effected not'as the result of such movement of the valve 11. toward the left, but as the result of a subsequent movement of the valve 11 toward the right due to the pressure in the chamber 19 falling below that of the valve-spring 18 when the pressure within the supplementary air-reservoir 0 drops as hereinafter stated.

For this burpose the cam-bar '29 is pro vided at its right-hand edge with a shoulder 36 so situated relatively to the shoulder 35 at the left-hand edge that the release the shoulder 35 (in consequence of the. rise ot pressure in the chamber 19 and movement of the valve 11 toward the left) will be immediately tollowed by the re-arrest of the cam bar 29 owing to the engagement oi the shoulder 36 against the right-hand end 37 of the slot 28 asshown in Fig. 30. The v cam-bar 29 now occupies what may be termed the half set position, (F

when the vehicle has been put away for unloading and the brakes on the vehicle have leaked oil. The cam-bar 29, is of such width between the shoulders 35 and 36 (one ot sesame which is slightlygin advance of the other) as to be only just capable of passing through the slot28, so that the end 3? oftheslot cannot fail to come into position to engage theslioulder 36 as soon as the end 33 0f the slotbecomes disengaged from the shoulder '35, and hence premature return of the cam-bar 29 -t o,-its'initialor idle position (Figs. 1 and dycannot'occur.

In operation, when-a loaded vehicle has been coupled-up to the brake-system of a train, the cam-bar'29 is moved by hand against the. pressure of the cam-spring 81 so as to bring the control valve piston 11, by the action of the cam-face 3% against the end 33 of the slot 28, from the closed position shown in Fig. 1 to the open position shown in Fig. 2, in opposition to the valve-- spring 18, the cam-bar 29 becoming locked in the operative position by engagement of its shoulder 35 with the slotted rod. v After the train-coupling operation is complete and the brake apparatus charged with air, the 311- pressure maintained in the tram-pipe a during the continuance of ordinary running conditions gains access, byway of the pipe 15, port 13, valve-piston 11, portv 14:, and pipe 16, to the supplementary air-reservoir c and thence to the variable air-pressure cha aber 19, and, by exerting a pressure against the valvepiston 11 further moving the latt r in opposition to the valve-spring 18, causes the shoulder 35 on the-cam-bar 29 to become freed from the slotted rod 26 so as to permit the engagement with the latter of the shoulder 3-6, as shown in Fig. 3. So

lon as normal working air-aressure is p o maintained in the supplementary a1r-reservoir c and variable air-pressure chamber 19, the supplementary brake-cylinder 2') remains capable of operating in conjunction With the primarybrake-cylinder b of the vehicle, as is required for braking the vehicle when loaded, this state of affairs continuing so long as the vehicle remains coupled-up with the train and the latter is kept under running conditions. 7

When the vehicle is put aside for unloading, the complete release ofpressure from the brake apparatus (consequent upon the opening of the train-pipe a and the c and variable air-pressure chamber 19 being new cut off from the train-pipe a by,

the closure of the control-valve, it follows that, if "the unloaded -vehicle be again put into running condition, the supplementary brake-cylinder w1ll-rema1n lnoperative,

as is required for braking the vehicle whenempty;

I claim 1. 1n anautomaticjfluid-pressure brake a1 paratu's, the combination of a trainpipe,

asuppl'em'entary fluid-pressure reservoir,- a

supplementary brake-cylinder, atriple valvle connected with said reservoirand'said cylinder, a; connection between the triple valve and theitrain-pipe, a control-valve 1n saidv connection, a spring under the *action'of which said valve constantlyvtendsto assume a closed posit on'in which SELlClCOIlllCtlOIL is closed, a manually-operable, cam for moving saidvalve to an. open position inwhich said connection is open, a spring for restoring said cam to its inoperative position and means whereby, when pressure exists in the supplementary fluid'pressure reservoir, al-

thoughthe'controlevalve still remains open,

said cam becomes potentially freed to the actionof said spring in such a manner that,

on the brakes being completely released or allowed to leak off, the cam will be automa tically restored to inoperative position, thus permitting the automaticreturn of the control-valve itself-to the closed position, sub.-

'stantially as and forthe purpose set forth.

2. In an automatic fluid-pressure brake] apparatus, the combination of-a' train-pipe,

a primary braking mechanism connected therewith, a supplementary"braking mechanism connected'with said train-pipe and arranged to supplement the action of said primary braking-mechanism, controllingmeans whereby the connection between said supplementary braking mechanismand said trainpipe is controlled, manually operable.

means for actuating said controlling-means to open said connection, said controlling means being maintained inopen position by mechanism and means whereby said-manupressure in said supplementary braking ally operable means is automatically restored to its inoperative positionand said controlling-means is automatically actuated to close, said connection when said pressure is released. Y

3. In an automatic fluid-pressure brake apparatus, the combination of a tram-plpe I a primary braking mechanism connected therewith, a supplementary braking mechanism connected with said "train-pipe and arranged to supplement the action of said primary braking-mechanism, controllingmeans whereby the connection betweensaid supplementary braking mechanism and said train-pipe is controlled, a cam whereby said controlling-means isv actuated to open said connection, said cam being held by said controlling-means and being released as pressure in said supplementary braking mech- Lil anism drops and means for automatically causing said controlling-means to close said connection when said cam is released.

4:. In an automatic fluid-pressure brake apparatus, the combination of a train-pipe, a primary fluid-pressure reservoir, a prirnary brake-cylinder, a primary triple-valve connected with said train-pipe, said brakecylinder and said reservoir, a supplementary fluid-pressure reservoir, a supplementary brake-cylinder connected therewith, a supplementary triple-valve in said connection,

a valve-casing, a connection from said valve casing; to said train-pipe, a connection from said supplementary triple-valve to said valve-casing, a controlling-valve in said casing whereby communication between said two last named connections is controlled, a spring at one end of said valve whereby the latter constantly tends to assume a position in which said communication is closed, a connection leading from said valve-casing behind the other end of said valve to said supplementary fluid-pressure reservoir and a manually operable cam whereby said valve is actuated against the tension of said spring to open said communication.

ARTHUR- MORTON BELL;

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