US3589528A - Valve apparatus for controlling train action events - Google Patents

Abstract

A valve apparatus for controlling ''''run-in'''' train action events. The valve is characterized by a valve member which is normally open to provide a low impedance level in an hydraulic cushioning device capable of effectively absorbing buff coupling shock. Fluid reaction surface means associated with the valve member enables the valve member to move to a relatively closed position to provide a high impedance level and thus enable the cushioning device to control ''''run-in'''' train action events. A disabling device obviates the function of the reaction surface means, when buff coupling forces act on the cushioning device, so as to cause the valve member to remain open.

Description

mite States Primary Examiner-Drayton E. Hoffman Attorney-Burns, Doane, Swecker & Mathis ABSTRACT: A valve apparatus for controlling run-in" train action events. The valve is characterized by a valve member which is normally open to provide a low impedance level in an hydraulic cushioning device capable of effectively absorbing buff coupling shock. Fluid reaction surface means associated with the valve member enables the valve member to move to a relatively closed position to provide a high impedance level and thus enable the cushioning device to control run-in train action events. A disabling device obviates the function of the reaction surface means, when buff coupling forces act on the cushioning device, so as to cause the valve member to remain open.

PATENTEU JUN29 I97! 3589528 sum 1 or 4 BY zws QM, w w

ATTORNEYS PATENTEU JUN29 I971 sum 2 OF 4 INVENTOR JACK GA STEPHENSON av am, QM, Zin -4 41M Mr ATTORNEYS PATENTED JUN29 1971 SHEET 3 0F 4 INVENTOR JACK G. STEPHENSON ATTORNEYS PATENTEUJUNZSIQY: 3.589528 SHE-ET t 0F 4 INVENTOR JACK G STEPHENSON BY 3am gow maffiuwf ATTORNEYS VALVE APPARATUfi lFOlit CONTROLLING TRAIN ACTION EVENTS RELATED APPLICATION This application pertains to a valve apparatus which may be utilized advantageously in a railway cushioning device, the structure and mode of operation of which are set forth in U.S. application Ser. No. 744,947, filed July 15, 1968, and assigned to the assignee of the present application.

GENERAL BACKGROUND, OBJECTS AND SUMMARY OF INVENTION Railway freight cars often carry goods and commodities which must be protected from shock. Thus, there has been a longstanding practice in the railway art to provide cushioning mechanisms in association with car coupling devices. Such mechanisms enable shock forces, generated during car coupling operations, to be absorbed without transmitting excessive shock to goods contained within the railway cars being coupled.

While cushioning devices provide a mechanism for absorbing coupling shocks, there still remains the problem of coping with train action events.

Train action events may be defined as a phenomena which occurs as a consequence of the existence of slack in the couplings between moving railway cars. Such slack enables the cars, in motion on a railbed, to undergo relative movement. Thus, train action" denotes the equalizing of speed of adjacent cars which have undergone relative movement. A train action event is termed a run-out where adjacent cars are moving apart. Where moving cars are converging, the train action event is termed a run-in..

There are several undesirable aspects associated with train action phenomena. While train action is occurring, crewmen experience an undesirable floating" sensation. At the termination of train action events, shock forces are transmitted to coupling units and railway cars and often transmitted in a more or less wave form throughout a train. Such train ac tion induced shocks are often severe enough to both damage goods carried by a train and cause injury to train erewmen. lndeed, the train action induced shock forces may be so severe as to induce derailment.

A major contribution to the railway cushioning art which provides a system for effectively coping with run-out" train action events is featured in Stephenson et al. U.S. Pat. No. 3,451,561.

While the stephenson et al. concept provided a concept for effectively handling a run-out event, there remained a need, going beyond the teaching of this concept, for a method and apparatus which would effectively minimize or control runinevents.

The problems involved in coping with run-in" events are particularly aggravating and seemingly mutually inconsistent from the standpoint of solutions.

The greatest forces ordinarily imposed upon a coupling are those encountered in a railway yard where a train is moving at relatively low speed and abruptly engages a car for coupling purposes. ln'order to absorb the high level shock generated during such coupling operations, it is necessary that a cushioning device have a capacity to move relatively rapidly and dissipate large amounts of energy on a fairly uniform basis.

However, when a train is in motion and lower level forces are acting on the coupling units so as to tend to induce a runin" phenomena, i.e., induce convergence of coupling units, the requisites of the cushioning device necessary to absorb high level coupling shocks are self-defeating. With the coupling unit being able to move rapidly so as to absorb coupling shock, its capacity to cause slow coupling movement so as to control run-in" events is severely restricted.

Conversely, if the cushioning mechanism is designed to impede coupler movement to an extent sufficient to control run-in events, the cushioning device will be unable to effectively absorb the high energy coupling shocks.

A particularly acute problem relates to the provision of a mechanism for controlling the impedance level in a cushioning device, which mechanism will operate with sufficient rapidity and reliability to control both run-in" events and buff coupling forces acting on the cushioning mechanism.

It thus is a principal object of the present invention to provide a control valve mechanism, uniquely adapted for incorporation in an hydraulic cushioning mechanism associated with a railway car, which valve mechanism is normally open and remains open to absorb coupling shock and is closed in response to run-in" train action forces so as to provide a higher impedance level.

It is a further object of the invention to provide such a runin" control valve, including a low inertia disabling component which acts rapidly to maintain the valve in an open condition in response to buff coupling forces.

A further object of the invention is to provide such a runin control valve including a valve member and disabling member, which traverse overlapping paths so as to maintain the control valve within minimum dimensions.

Another object of the invention is to provide a simplified valve structure characterized by telescopingly assembled components, with at least two of these components being biased by a single spring mechanism.

It is another object of the invention to provide such a runin control valve characterized by structural simplicity and inherent ruggedness and a mounting arrangement which positively prevents valve components from entering into the interior of the cylinder of an hydraulic impedance mechanism.

In accomplishing certain of the foregoing objects, there is presented through this invention, a method of controlling train action phenomena wherein an impedance means is provided between relatively movable draft gear cushioning members. The impedance means is operable to impede buff movement of the draft gear.

The term buff movement, as here used, denotes in the conventional sense, the movement of a coupler bar toward a railway car occasioned by forces such as those generated during coupling operations. Draft movement on the other hand indicates outward movement ofa coupling bar, i.e., movement of a coupling bar away from its associated railway car in response to pulling forces acting on the coupling bar.

In response to the buff forces acting on the draft gate tending to produce run-in train action events, a first level of impedance to movement is provided by the impedance means. In response to buff coupling forces acting on the draft gear, i.e., buff forces generated during coupling operations, a second level of impedance is provided which is substantially less than the first level ofimpedance.

In a preferred embodiment, this basic concept is augmented by providing other hydraulic impedance means between the draft gear cushioning members. This other hydraulic impedance means is operable to impede draft movement of railway car draft gear. In response to draft forces acting on the draft gear and tending to provide run-out" train action events, a relatively high impedance level is provided in the other impedance means. In response to low level draft forces acting on the draft gear, a relatively low impedance level is provided in this other impedance means.

The invention here presented relates to a run-in" control valve incorporated in an overall impedance system as described in an application of Seay et al. filed July 15, 1968 and entitled ,Method and Apparatus for Controlling Train Action Events.

ln accomplishing at least some of the foregoing objects, there is presented, through this invention, a run-in" control valve characterized by a normally open valve. In its open condition, this valve provides a low impedance level resisting buff coupling forces. Actuating means associated with the valve move the valve to a closed position in,response to run-in" forces acting on a cushioning mechanism. A low inertia, disabling device serves to obviate the influence of the actuating means when buff coupling forces are acting upon the cushion device.

In a specific format, the valve mechanism includes body means and passage means extending through the body means and operable to provide fluid communication between the impedance zone of a cushioning device and a low pressure, fluid discharge zone of the cushioning devicev A valve member is mounted for telescoping movement in the body means and is operable to control flow through the passage means. A fluid reaction means is operably associated with the valve member and is operable to move the valve member to a position impeding flow through the passage means in response to flow from the impedance zone to the low pressure discharge zone. Port means provide fluid communication between the passage means and the fluid reaction means. A valve disabling means is operable to tend to close the port means, in response to a rate of movement of a railway coupling member connected with the cushioning device which results from any anticipated buff coupling forces acting on the coupling member. A biasing means resiliently urges the valve member to a position opera ble to permit flow through the passage means.

DRAWINGS In describing the invention, reference will be made to a preferred embodiment shown in the appended drawings.

In the drawings:

FIG. 1 provides a perspective view of a railway car and components of a cushioning mechanism and a coupling bar, with these components being shown in an exploded or separated format;

FIG. 2 provides an enlarged, sectioned, elevational view of the cushioning mechanism shown in FIG. 1;

FIG. 3 provides a plan view of the inner cylinder wall of the FIG. 2 cushioning device, with this wall laid flat";

FIG. 4 provides an enlarged, transverse, sectional view of the FIG. 2 cushioning device as viewed along the section line 4-4 of FIG. 2;

FIG. 5 provides a transverse, sectional and enlarged view of the FIG. 2 cushioning device as viewed along the section line 5-5 of FIG. 2;

FIG. 6 provides an enlarged, elevational, and sectioned view of a valve mechanism incorporated in the FIG. 2 mechanism, which valve mechanism is operable to control flow through cylinder ports during buff movement of the draft gear, i.e., coupling bar. The valve components are shown in FIG. 6 in their relaxed or normal condition, i.e., with no fluid forces acting on the components; I

FIG. 7 illustrates the components of the FIG. 6 assembly as they are disposed during an outflow of fluid from the inner cylinder of the FIG. 2 mechanism so as to control run-in" train actions events;

FIG. 8 illustrates the components of the FIG. 6 assembly as they are disposed during an outflow of fluid from the inner cylinder of the FIG. 2 assembly in response to coupling shock acting on the coupling member;

FIG. 9 provides a transverse sectional view of the FIG. 6 assembly as viewed along the section line 9-9 of FIG. 6;

FIG. 10 provides a transverse sectional view of the FIG. 6 assembly as viewed along the section line 10-20 of FIG. 6;

FIG. ll provides a transverse sectional view of the FIG. 6 assembly as viewed along the section line 11-11 of FIG. 6;

FIG. 12 provides a bottom plan view of the underside of a railway car sill illustrating details of an anchoring system for securing the piston rod of the FIG. 2 mechanism to the sill;

FIG. 13 provides an enlarged, transversely sectioned, view of a check valve mechanism incorporated in the FIG. 2 mechanism, which check valve mechanism enables fluid to return to the interior of the inner cylinder of this mechanism during draft movement of the coupling bar; and

FIG. 14 provides an enlarged transversely sectioned view of a valve mechanism mounted at the draft end of the inner cylinder of the FIG. 2 mechanism and which serves to control "run-out" train action events.

BASIC STRUCTURE FIGS. 3 and 2 illustrate the basic components ofa cushioning mechanism designed to be incorporated in a railway freight car in conjunction with a conventional drawbar or coupler.

Cushioning mechanism 1 includes cylinder means 2. This cylinder means comprises an outer cylinder 3 and an inner cylinder 4. A piston means 5 is telescopingly associated with the cylinder means 2. Piston means 5 includes a piston 6 mounted for telescoping movement within the interior cavity 7 of cylinder 4. Piston means 5 includes a piston rod 8 extending from one side only ofthe piston body 6.

An anchor assembly or anchor means 9 serves to connect the piston means 5 to the sill 10 of a railway car 1}. Anchor means 9 comprises a conventional spherical bearing assembly 12 carried at the free extremity of the piston rod 3. This spherical bearing assembly 12 is secured within a unitized precast housing 13. The housing 13 is secured within the sill 10 as, for example, by conventional welding techniques.

A continuation of outer cylinder 3 defines a connecting means 14 which serves to connect the cylinder means 2 with a conventional drawbar 15.

A restoring mechanism 16 provides a resilient interconnection between the sill 10 and a tongue portion 17 of the cylinder means 2. Restoring mechanism 16, fabricated from coil springs, serves to yieldably and resiliently bias the cylinder means 2 to a predetermined neutral or rest position. Restoring mechanism 16 may be of the general type described, for example, in the Abbott et al. US. Pat. No. 3,233,747.

The general manner in which a cushioning mechanism is mounted on a railway car structure is well understood and described, for example, in the Abbott et al. US. Pat. No. 3,233,747, as well as in said Stephenson et al. US. Pat. No. 3,451,561.

Suffice it to say, with reference to FIG. 2, that the cushioning device I is mounted within the sill 10, with the piston means 5 fixedly anchored to the sill 10 by way of anchor means 9. The cylinder means 2 is free to undergo longitudinal telescoping movement within the sill 10.

Buff movement of the cylinder means 2 is limited by engagement of collarlike abutment means 1%, carried by connecting means 14, with collarlike abutment means 19 carried by the outer end of the sill 10. Draft movement of the cylinder means 2 is limited by engagement of the piston means 6 with an annular check valve member 20 defining the draft end of cylinder space 7.

Restoring mechanism 16 is connected, at one end, by bracket means 21 to a sill baseplate 22. Sill plate 22 is fixedly connected to the underside of sill 10 so as to provide support for the underside of cylinder means 2.

Another portion of restoring mechanism 16 is connected with the tongue portion 17 of cylinder means 2.

The coil spring components of restoring mechanism 16 tend to yieldably bias the cylinder means 2 toward a predetermined neutral position as described in detail in the aforesaid Abbott et al. US. Pat. No. 3,233,747. In connection with this invention, the predetermined neutral position is the position at which the piston means 6 engages the draft extremity of cylinder space 7, Le, the check valve 24).

It will here be recognized that ability this neutral position, the restoring mechanism 16 need not have a capacity to restore in a buff direction. It is necessary only for the restoring mechanism to return the cylinder means 2 from the full buff position illustrated in FIG. 3, in a draft direction, to the neutral position. Thus, if desired, the structure of the restoring mechanism described in the Abbott et al. patent may be simplified to eliminate the ability of the Abbott et al. restoring mechanism to resiliently bias the cylinder means 2 in a buff direction.

CYLINDER STRUCTURE As noted, cylinder means 2 includes outer cylinder 3 and inner cylinder 4. Outer cylinder means 3, as shown in FIG. 2, 4i and 5, has a generally rectangular crosssectional configuratron.

lnner cylinder 4, which is contained within and spaced from the outer cylinder 3, has a generally cylindrical or circular cross section.

' Cylinder 4 is spaced from cylinder 3 so as to provide a generally annular, low pressure cavity 23. Because of the relatively low pressure nature of the fluid contained within this cavity, the sidewall 24 of cylinder 3 may be relatively thin in relation to the sidewall 25 of cylinder 4. Cylinder 4 contains the high-pressure cavity 7.

The ends of cylinder means 3 and 4, adjacent anchor means 9, may be termed first cylinder ends. The first end of outer cylinder means 3 is defined by a cylinder head 26. The first end of inner cylinder means 4 is defined by a cylinder head 27. Cylinder heads 26 and 27 are both centrally aperturcd to telescopingly receive the piston rod 8.

A bushing 28 provides a bearing relationship between the cylinder head 27 and piston rod 8. An assembly 29 of conventional annular seals is provided in cylinder head 26 to maintain a sealed relationship between the cylinder head 26 and the reciprocable piston rod 8.

it is here significant to note that the seal mechanism 29 is disposed in an annular recess 29a formed in cylinder head 26. Recess 29a faces outwardly so as to provide access to the seal assembly 29 from the exterior of the unit. Seal assembly 29 may be retained in place in recess 29a by an annular cover plate 2%. Plate 2% may be secured in place by conventional threaded fasteners, as shown in FIG. 2.

An accordianlike elastomeric dust shield 30 is connected at one end 31 to cylinder head 26 and the other end 32 to piston rod 8. This dust shield structure protects the portion of the piston rod 8 which reciprocates into and out of the cylinder means 2.

As shown in H6. 2, note that cylinder head 27 is stabilized by cylinder head 26. This support is achieved by a plurality of circumferentially spaced and radially directed webs 33 extending longitudinally between the cylinder heads 26 and 27. As illustrated, the longitudinal spacing of cylinder heads 26 and 27 and the circumferential spacing of the webs 33 provides passage means 32 defining a continuation of the lowpressure cavity 23. This passage means 34 communicates with the rightmost end of cylinder head 27, viewing the apparatus as shown in FIG. 2.

The end of cylinder means 2 disposed adjacent connecting means 14 may be termed the second cylinder head or second cylinder end,

Thus, the second end of cylinder means 3 is closed by generally annular, second cylinder head means 35. The second end of inner cylinder means 4 is closed by second cylinder head means 36.

As illustrated, cylinder head means 35 and 36, in essence, are defined by an integral wall extending entirely across the second end of cylinder means 2.

Inner cylinder wall means 25 may be mounted in an interfering fit relationship on an annular ledgelike portion 37 of the unitary wall means 38 which provides cylinder head means 355 and 36. A similar mounting arrangement interconnects wall 25 with cylinder head 27.

Port means 39 provide communication between the highpressure cylinder cavity 7 and the low-pressure cylinder cavity 23. For purposes of convenience of illustration, all of the ports of port means 39 are illustrated in FIG. 2 as though they were aligned with the median longitudinal plane of the cylinder wall 25v it will be understood, however, that the actual disposition of these ports is more accurately reflected in FIG. 3.

During buff movement of the cylinder means 2, the cylinder head wall 36 moves toward the leftmost side of piston means 6, viewing the apparatus as shown in H6. 2, so as to expel fluid from the cylinder cavity portion "in into the low-pressure zone 23. Fluid expelled from the cavity 7a enters the low-pressure zone 23 and flows into the passage means 34. This fluid is returned to the cylinder zone 7b, disposed between the rightmost side of piston 6 and the cylinder head 27, by way of a check valve 20.

Check valve 20 comprises a generally annular valving plate 20:! mounted on cylinder head 27 within cavity 7. Plate 20a is valvingly associated with a plurality of longitudinally extending and circumferentially spaced, high capacity passages 40 formed in cylinder head 27. A series of circumferentially spaced coil spring unit 411 serve to yieldably and resiliently bias the plate 20a toward anchor means 9, into passage closing relationship with the passage means 4i). Each such biasing mechanism 4ll comprises a coil spring 42 interposed between an abutment 33, carried by valve plate 20:: by way ofa rod 44, and an abutment 45 formed in a cylinder head passage to.

The structure and mode of operation of this check valve mechanism is described in detail, for example, in the Blake U.S. Pat. No. 2,944,681. For present purposes, it is sufficient to note that fluid expelled from space 7a and transmitted to This fluid expelled from cavity 7b will return to cavity 7a by way of a first port 47 in port means 39. Port 457 is disposed in the underside of cylinder wall 25 and provides fluid communication between the cavities 7a and 23 throughout the extent of draft travel of the cylinder means 2.

A check valve mechanism 43, illustrated in detail in FIG. 13, provides continuously, check valve controlled communication between the cavity 7a and the cavity 23. The flow capacity of the port means 47, when placed in an open condition by check valve 48 is of a relatively high magnitude, so as to afford nominal resistance to return flow of fluid from lowpressure cavity 23 through the zone 7a.

Structural details of the check valve mechanism 458 are shown in FIG. l3. As there shown, mechanism 48 comprises a body 39 connected by threaded coupling means 50 to the exterior of wall 25. A valve member 53 is telescopingly mounted within valve body 49.

Valve member Sll is generally cylindrical in character and includes a cylindrical sidewall 52 provided with a plurality of radial ports 53. An impcrforate head wall 54, connected with sidewall 52, provides a sealing surface 55 to sealingly engage a valve seat 56 formed on valve body d9. A coil spring 57 interposed between valve member carried abutment 53 and a valve body carried abutment 59 serves to yieldably bias the valve member 5i to a closed position.

in response to a relatively low-pressure in cavity 70., resulting from draft movement of cylinder means 2, the valve 5!. will automatically open so as to allow the return flow of fluid from cavity 23 into the zone 7a.

PISTON MEANS AND ANCHOR STRUCTURE The structure of piston means 5 and anchor means 9 is illustrated in H08. 2 and 112.

Piston means 5 includes the piston 6. A bushing 60 is supported in an annular, notchlike recess fill formed on the outer cylindrical periphery of piston 6. Bushing 60 may be secured in place by an annular plate 62 secured to piston body 6 by threaded fastener 63. A generally annular sealing element 64 is carried on the outer periphery of bushing 60 and provides sliding and substantially sealing engagement between the outer periphery of the piston 6 and the inner periphery of wall 25 of cylinder means 4. Element 6 5 may comprise a split" piston ring operable to provide highly limited leakage between zones 70 and 7b, as described in the aforesaid Stephenson application.

Piston rod 8 extends from one side only of piston body 6 and intersects the first ends only of cylinder means 3 and 4. Thus, piston 6 is supported in a cantilever fashion within cylinder means 4, with there being no piston rod extending into the cavity portion 7a or through the second cylinder end plate 38.

Piston rod 8 is sealingly and slidably supported during its reciprocable passage through cylinder heads 27 and 26 by bushing 28 and seal means 29.

The free, or rightmost extremity of piston rod 8 terminates in the spherical bearing assembly 12. This spherical bearing assembly 12 is of the type described, for example, in the aforesaid Blake U.S. Pat. No. 2,944,681.

For present purposes, it is sufficient to note that this spherical bearing assembly, which serves to accommodate nonaxially directed stress, comprises a headlike portion 65 providing arcuate spherical segment surfaces 66 and 67. A bearing plate 68 conformingly engages surfaces 66 while another bearing plate 69 conformingly engages surface 67. Plates 68 and 69 are interconnected as described generally in the aforesaid Blake U.S. Pat. No. 2,944,681.

Unitized housing 13 of an anchor means 9 comprises a pair of sidewalls 70 and 71. These walls extend longitudinally of the sidewalls 72 and 73 of sill 10. Housing sidewalls 70 and 71 may be welded to sill sidewalls 72 and 73 respectively.

Housing sidewalls 70 and 71 are interconnected by a pair of longitudinally spaced, and transversely extending, walls 74 and 75, Wall 75 is provided with an aperture 76 of a size sufficient to receive the spherical bearing assembly 12.

With spherical bearing assembly 12 inserted through the aperture 76 of the welded-in-place housing 13, it will be positioned such that the plate 69 abuttingly engages an abutment or stop portion 740 carried by the transverse wall 74 of housing means 13.

With the spherical bearing assembly 12 thus disposed in abutting engagement with the stop 74a, the assembly 12 may be fixed in position relative to the housing 13 by inserting a securing plate 77. Securing plate 77, as shown in FIG. 1, is U- shaped and includes a pair of laterally spaced legs 78 and 79. Plate 77 is installed through the open underside 30 of housing 13 so as to straddle the piston rod 8, with the legs 78 and 79 disposed on opposite lateral sides of the piston rod 8. The width of the plate 77 is such that when it is disposed in this straddling position, it bridges the longitudinal clearance between plate 68 and the housing wall 75, assuming, of course, that plate 69 is abuttingly engaged with the stop 74a. With anchor plate 77 thus positioned, it may be secured in place by conventional threaded fasteners 8% which pass transversely through the housing wall 75 and the lower wall portion 82 plate 77 which connects the legs 78 and 79.

HYDRAULIC FLUID SYSTEM When the cushioning mechanism 1 is assembled, oil may be introduced into the cavity 7 through conventional filling orifices (not shown). Oil is introduced when the piston 6 is in the full buff position shown in FIG. 2. The volume of oil is adjusted so as to fill the total void space of cavities 7a, 7b, 23 and 34, except for a volume equal to one-half of the volume of piston rod 8 which reciprocates into and out of the cavity 7, i.e., the change in volume of cavity 7 caused by reciprocation of piston rod 8.

This degree of filling will leave, in the total void space of cylinder means 2, when the piston is in the full buff or contracted position, a void or air space equal to one-half of the piston rod volume which reciprocates into and out of the cavity 7. At the other extremity ofpiston movement, i.e. when the cylinder is in the extended or draft position, this void space will be equal to one and one'half times the piston rod volume which moves into and out of the cavity 7.

Even at the draft position of the cylinder means 2, the air void, which comprises an air body in direct communication with the hydraulic oil of the system, will exist only in the top of cavity 23 and above the cavity 7. Thus, the free air or void space will not extend into the hydraulic impedance zone 7.

Nevertheless, this air, being in direct contact with the oil body, will be capable of intermixing with the oil as relative movement between the piston means 5 and cylinder means 2 occurs. It has been found, quite unexpectedly, that this intermixing, which may produce air bubbles within the oil contained in cavity 7, does not deleteriously affect the ability of the oil in cavity 7 to control train action events and absorb high impact shocks.

This air void will provide an effective mechanism for accommodating the expansion of oil which results from oil heating during shock absorbing action.

Somewhat surprisingly, it has been found that the air void may be reduced to the point where virtually no air exists in the system when the cylinder is in the full buff position shown in FIG. 2. Even under this condition, the system will still accommodate the thermally induced expansion of the hydraulic oil.

RUN-IN" AND BUFF SHOCK CONTROL SYSTEM The impedance to coupler bar movement during buff move ment of cylinder means 2 is controlled by a plurality of exponentially spaced ports 83 through 94 included in the port series 39.

These exponentially spaced ports are arranged on cylinder wall 25, generally as shown in FIG. 3.

FIG. 3 represents cylinder wall 25, separated at median and longitudinally extending line 26, and laid flat. Line 26 represents the intersection of the longitudinally extending vertical median plane passing through the cylinder means 4 with the upper portion of wall 25. The general location of line 26 is shown in FIGS. 4 and 5.

The exponential spacing herein-referred to corresponds generally to that described, for example, in the Seay U.S. Pat. No. 3,30l ,410 and described also in the previously noted Stephenson et al. Patent No. 3,451,561.

In one embodiment of the invention, where the piston 6 is operable to reciprocate longitudinally within cavity 7 through an increment of about 15 inches, and where the inner diameter of cylinder wall 25 is approximately 8 inches, and where piston rod 3 has a diameter of approximately 3 /4 inches, the exponentially spaced ports 83 through 94 are spaced from the cylinder end 95, in a direction measured longitudinally or parallel to the junction 26, in general accordance with the following tabulation:

Distanee in inches Port: from cylinder ends 95 83 2. 00

S5 a s 2. 44

All of the ports 83 through 94, in the embodiment characterized by the dimensions above-noted, are of the same diameter, i.e., nineteen sixty-fourths inches.

In this embodiment the longitudinal width of the piston 6, i.e., the distance between piston sides 6a and 6b, is approximately 2 and 6 inches.

In the full buff position of piston 6, this piston covers ports 83 through 88. Each of these six ports adjacent cylinder end 95 are individually controlled by a control valve 96. Thus, ports 89 through 94 are continuously open and unvalved, while ports 83 through 38 are each under the control of an individual valve 96.

In order to facilitate the overall illustration of the invention, the various valve mechanisms 96 associated with the ports 03 through 88 of port system 39 are not shown in FIG. 2. How ever, the positioned relationship of valves 96 are shown in FIGS. 3, 4 and 5.

Structural details of a representative control valve 96 are illustrated in FIGS. 6 through 11. As there shown, the control valve 96 comprises a generally cylindrical body 97. A threaded coupling 90 serves to threadably secure the valve 96 to the exterior of the wall 25 in a radially extending alignment with respect to the central axis of the cylinder means 4 and in coaxial disposition with its associated port. The valve 96, illustrated in FIGS. 6 through 11, is shown in association with the first port 03 in the exponential series.

As shown in FIGS. and 5, the various valves 96 are arranged so as to project into the enlarged corner portions of the generally annular cavity 23, where maximum space is available.

Returning to the basic structure of valve 96, each valve includes a reciprocable, generally cylindrical, spool valve member 99. Each such spool valve member includes a generally cylindrical body portion 100 having a closed, radially outermost, extremity 101. A plurality of radially extending ports 102 intersect the cylindrical wall portion 100, immediately beneath the end wall 101. In the embodiment characterized by the dimensions above-noted, four ports 102 are provided, each having a diameter of eleven sixty-fourths inches.

The end 103 of valve 99, facing the central axis of the cylinder means 4, is open as shown in FIG. 6.

Each reciprocable valve further includes a generally annular rimlike piston 104. This piston extends radially outwardly from cylinder wall 100, generally adjacent the free end 103.

A second series of radially extending and circumferentially spaced ports 105 intersects cylinder wall 100 adjacent piston 104.

An annular shoulder or ledge 106 if formed on the outer periphery of cylindrical wall 100. Ledge 106 faces generally axially, toward the head portion 101 of valve 99.

A valve body cap 107 closes the outermost end of the valve body 97 and telescopingly receives the cylindrical wall 100. As illustrated, closure or cap 107 may be disclike in structure. Closure 107 is provided with a central aperture 106 through which cylindrical wall portion 100 reciprocates.

Closure 107 provides an annular abutment 109, extending radially outwardly from a cylindrical cap surface 110, which surface defines aperture 106. With abutment 106 with abutment 109, the main valve ports 102 are positioned so as to clear, i.e., be spaced outwardly from, the outer extremity 111 of closure 107.

Valve 99 is biased outwardly of the central axis of cylinder means 41 so as to bring the abutment 106 into engagement with abutment 109 by a coil spring 112. This spring 112 abuttingly engages an annular recess or seat 113 formed in the free end 103 of the valve wall 100.

As shown in FIG. 6, closure 107 cooperates with a radially extending valve body wall 114 and a cylindrical body wall 115 to define a generally annular cylinderlike cavity 116. Valve piston 104 is operable to reciprocate through cavity 116.

Port means 105 provide, by way of port 83, fluid communication between the high-pressure cavity 7 and the zone 1160 of cavity 116 which is disposed between the closure 107 and the piston 1.

A plurality of ports 117 intersect the generally hexagonal base wall 118 of valve body 97, immediately adjacent, but radially outwardly of, the cylinder end wall 114. Port means 117 thus serve to provide fluid communication between the low pressure cavity 23 and the portion 116k of cylinder cavity 116 disposed between piston 104 and valve body 114.

Thus, piston 104i is biased inwardly toward the central axis of piston means 1 by the pressure of fluid within the cavity 7. Piston 104 is biased radially outwardly, away from the central axis of cylinder means 41, by a generally low-pressure fluid within cavity 23.

Thus, when the higher pressure of fluid within cavity 7, acting through port means on piston 104, overcomes both the spring biasing of spring 112, and the fluid pressure of cavity 23 transmitted through ports 117 to piston 104, the valve 97 will move radially inwardly to a closed valve position, i.e., the position shown in FIG. 7. In this closed valve position, the ports 102 are covered and substantially closed by surface 110. Surface, is disposed in generally telescoping and conforming relation with the outer periphery 119 of valve wall 100.

In this connection, however, it will be understood that the relationship between outer periphery 119 of valve 96 and surface 110 may not be such as to provide complete sealing, i.e., some limited leakage may take place. Indeed, in the embodiment characterized by the dimensional criteria above-indicated, with the valve disposed in the FIG. 7 position, a degree of leakage through the valve takes place which is on the order of one-tenth of the flow permitted by the valve in the open position shown in FIG. 6.

It will here by understood that the reaction surface 104a provided by the piston 104 in the zone 116a is sufficient to provide a net downward biasing operable to overcome both the biasing influence of spring 112, the biasing of fluid pressure in the zone 11611, and any biasing acting outwardly on the valve 99 as a result ofa restricted flow through the ports 102.

The restoring or biasing force of spring 112 is ofa relatively low magnitude such that the valve member 97 will move to the closed valve position during any run-in train action phenomena. This results because the low velocity of piston 6 during run-in events is sufficient to generate enough pressure in cavity 7 and cavity 116a to induce closing movement of valve 99.

It is contemplated that, in some circumstances, the restoring mechanism 16 may serve to position the piston 6 at a neutral position where the piston 6 would be spaced from its extremity of draft movement. Under such circumstances, where the restoring mechanism 16 is imposing very low level forces on the piston 16 tending to restore the piston 16 from a full draft position to an intermediate neutral position, the spring 112 will overcome the pressure effects of fluid within the cavity 7, transmitted through the port means 105 and acting on the piston 10 2, so as to hold the valve 99 in the open position shown in FIG. 9. With the valve 99 thus held open during the restoring action, relatively rapid restoration will be assured.

Valve mechanism 96 includes a unique disabling device 120 which serves to maintain the valve 97 in an open position when the coupler bar 15 and cylinder means 2 are subjected to impact forces of the type encountered during coupling operations. Such operations ordinarily occur in railway yards where trains are being assembled and one car is moved into engagement with another with sufficient force to induce interlatching of the coupler bars of the two cars involved.

Because of the severity of such coupler forces, it is highly desirable to maintain an immediately effective low level of impedance in the unit 1, operable to dissipate impact energy in a generally uniform manner and without excessively stressing the cylinder components of the mechanism. This low level of impedance is in contrast to the high level of impedance previously described which is attained during run-in phenomena.

The high level of impedance during run-in" phenomena is necessary in order to impede coupler movements where the level of forces acting on the coupler units is relatively low in comparison to those encountered during coupling operations.

The low level of impedance effected by the valve mechanism 96 will now be described with relation to FIGS. 6 and 8.

Disabling mechanism 120 comprises a sleeve 121 mounted for telescoping movement within the valve member 99. As shown, sleeve 121 is generally cylindrical in configuration and has an open upper end 122 as well as an open lower end 123. Ends 122 and 123 are connected by a relatively thin walled, or recessed, cylindrical wall portion 124%.

Upper end 122 is telescopingly and slidably supported by cylindrical wall portion 125 of valve '99. The lower end 123 of sleeve 121 is telescopingly and slidably supported by a cylin drical wall portion 126 formed in the valve body 97.

Sleeve 121 is provided with a radially outwardly extending, ledgelike flange 127. Flange 127 defines an abutment which engages the end 128 of coil spring 112, i.e., the end of this spring opposite to the end 129 which is engaged by the seat 113.

In the normal or neutral position of valve 96 shown in FIG. 6, the spring 112 biases the flange 127 radially inwardly toward the axis of cylinder means 4 so as to cause the flange 127 to abuttingly engage an annular seat 129 formed in the valve body 97. With the flange 127 engaged with the seat 129, the spring 112 is operable to resist radially inward movement of the valve member 99.

The biasing effect of spring 112, both with respect to sleeve 121 and valve member 99, may be varied by selecting a spring 112 of appropriate resilience. This biasing effect may also be varied in accordance with the degree of spring prestressing which is dependent upon the distance between the seat 113 and the ledge 127, when this ledge is engaged wit the abutment 129.

The diameter of the port 83 is less than the outer diameter of the sleeve end 123. Thus, if the ledge 127 should rupture, radially inward movement of the sleeve 121 would be interrupted by engagement of the sleeve end 123 with the portion 130 of cylinder wall 25 which surrounds the port 83. In this manner, inadvertent entry of the sleeve 120 into the high-pressure cavity 7 is positively prevented.

When the coupler bar is subjected to coupling forces or impacts, there will be a tendency for the piston 6 to move relatively rapidly within the cylinder cavity 7. This tendency to undergo rapid movement will generate a high-pressure within the cavity zone 7a and tend to induce a relatively high velocity fluid flow, radially outwardly through the central passage 131 of the sleeve 121. This fluid flow, because of its relatively high velocity, will produce a substantial pressure drop longitudinally across the sleeve 121. This pressure drop will overcome the biasing influence of the spring 112 and cause the sleeve 121 to move radially outwardly with respect to the longitudinal axis of the cylinder means 4. It is anticipated that this sleeve movement will occur in response to all movements of drawbar 1S and cylinder means 2, relative to fixed piston means 5, in excess of inches per second. This rate of movement substantially embraces the entire buff impact range during car coupling action.

The outward movement of sleeve 121 will terminate when the outermost sleeve end 122 engages an annular abutment 132 formed in valve member 99. Abutment 132 comprises a generally radially extending wall projecting outwardly from a cylindrical wall 133. Cylindrical wall 133, in essence, defines the inner surface of wall 100.

With the sleeve end 122 engaged with the abutment 132, this sleeve end 122 is operable to close the ports 105, as shown in FIG. 8. With the ports 105 thus closed, the ability of the piston 104 to move the valve member 99 to a closed valve position is obviated.

Sleeve 121 is characterized by a substantially lower inertia factor than that possessed by the valve 99. This difference in inertia will tend to cause the sleeve 121 to move relatively rapidly to the FIG. 8 position, before fluid pressure is able to build up in the zone 116a and induce movement of the piston 104. Further, a high velocity flow through the passage 134, and through the central passage of the valve member 99, will tend to create a velocity reaction force acting on the valve head 101 so as to tend to hold the valve member 99 in its open position while the sleeve 121 is moving to its disabling position.

It will also be appreciated that, even apart from the low inertia characteristic of the disabling sleeve 21, the restricted flow path defined by the ports 105 will somewhat delay the generation of sufficient force in the zone 116a operable to act on the piston surface 104a and move the valve member 99 to a closed valve position. The individual influences of either the low inertia of the sleeve 121, the restrictive influence of the ports 105, or the fluid reaction on the head 101, or the combined influence of these factors, ensures that a rate of fluid flow passing through the passage 131 sufflcient to induce movement of the sleeve 121, will cause the sleeve 121 to move to its disabling position before the piston 104 is able to move the valve 99 to a closed valve position.

However, once the valve 99 has moved to the closed valve position of FIG. 7, it is unlikely that sleeve 121 will be able to move radially outwardly to close the ports so as to obviate the biasing influence of piston 104-. The closing of ports 102 will probably prevent a flow of sufficient velocity through the passage 131 to induce movement of the sleeve 121. This valve characteristic, however, is not believed to be of adverse consequence because during run-in phenomena, train action forces would not be expected to approach the magnitude of coupling forces so as to require that the ports 102 remain open.

It will here be noted that with the valve components disposed as shown in FIG. 8, the wall 133 defines a substantially smooth-walled continuation of the inner wall 134 of sleeve 121. This results, of course, from walls 133 and 134 having the same circular cross section, i.e., the same internal diameter.

It will here be recognized, that the level of impact forces required to induce the disabling operation of the sleeve 121 will be determined, to a large extent, by the resistance to sleeve movement offered by the coil spring 112.

Where each of the valves 96 associated with the ports 83 through 88 is identical in structure, and includes a coil spring 112 of identical configuration and resilience, the various disabling sleeves 121 should operate in unison, and immediately in response to the imposition of coupling forces on the drawbar 15.

This will ensure that the exponential pattern of the ports 83 through 94 remains fully operative during the high impact condition so as to facilitate or contribute to a substantially linear disposition of energy in the manner described in Seay US. Pat. No. 3,301,410.

At this point it will be recognized that even the lower level impact forces encountered during coupling action will be suf flcient to induce the disabling operation of the sleeves 121 of the various valves 96 individually associated with the ports 83 through 88. This results because, even under the influence of relatively low impact coupling forces, the flow velocity through the passage 134 will be substantially higher than that encountered during run-in" train action phenomena, and thus will be operable to move the sleeve 121 to the disabling position shown in FIG. 11.

In the system here described, it is contemplated that each of the valves 96 will be of identical configuration and operating characteristics. Thus, during run-in" phenomena, each of the valves 96 associated individually with the ports 83 through 88 should close more or less simultaneously, in response to runin" phenomena.

However, it is recognized that under certain conditions, it may be desirable to provide valves 96 which operate in sequence or at different times so as to provide progressive closing off or constricting of the ports.

It will also be recognized that the number of ports required to control run-in" phenomena may vary, depending upon operating conditions, and that the number of these ports which are valved may vary, depending upon operating criteria.

SYSTEM FOR CONTROLLING RUN-OUT PHENOMENA The system incorporated in mechanism 1 for controlling "run-out" phenomena is illustrated in FIGS. 2 and 14.

This system includes, as a part of the port means 39, a relatively small capacity port 135 and a somewhat larger capacity port 136, provided with a control valve mechanism 137.

In the embodiment characterized by the dimensions previously indicated, the port 135 has an effective diameter of approximately 0.099 inches and the port 136 has a diameter of nineteen sixty-fourths inches However, fluid flow through port 136 is controlled by the substantially small flow capacity of the passage means of valve 137.

In this embodiment, the port 135 is spaced longitudinally from the edge 95 by a distance of approximately 16.62 inches. The port 136 is spaced from the edge 95 by a distance of approximately l9.72 inches.

Valve mechanism 137, as shown in FIGS. 14 and 5, is disposed in a lower corner of cavity 23. Control valve 137 is substantially the same as the run-out control valve described in detail in the aforesaid Stephenson et al. U.S. Pat. No. 3,451,56l.

In summary, this control valve 137 is characterized by a generally cylindrical valve body 138. Valve body 133 is attached by threaded fastening means 139 to wall 25. When thus attached, valve body 138 extends generally coaxially of port 136, i.e., radially of the central axis of cylinder means 4i.

Control valve 137 includes a generally cylindrical valve member 1 mounted for telescoping movement within valve body 138. A coil spring 141, interposed between a valve body ledge 142 and a flange 143 carried by valve 140, serves to bias the valve member 140 radially inwardly with respect to the cylinder means 4. Inward movement of valve member 1410 is limited by engagement of the flange 143 with a valve body ledge 1%.

Valve member 1410 is defined by a cylindrical wall 145 having an open upper end 146 and a closed lower end 147. One or more ports 148 intersect cylindrical wall 145 immediately adjacent the closed end 147.

With the valve member 141) disposed in the neutral position shown in FIG. 6, the flow controlling port means 148 is disposed in communicating relation with the cavity 7b. When the valve member 1411) is moved radially outwardly, by overcoming the biasing influence of spring 1411, a cylindrical wall 149 of valve body 138 valves-off" or closes the port means 148.

During run-out" train action phenomena, fluid flowing from the cavity 712, through the port means M3, and thence through the valve passage 151), to the low pressure zone 23 will induce, i.e., insure or maintain, a substantial pressure drop across the closed valve head 147. This pressure differential may also be viewed as resulting, at least in part, from the difference in pressure between the zone 7b and the zone 23, resulting from movement of piston 6.

Regardless of the manner in which the pressure differential is explained, its existence will serve to induce radially outwardly movement of the valve 140 in response to run-out" train action phenomena. This valve closing action will close off the port means 136, and thus provide a relatively high level of impedance operating against the piston 6 during run-out train action events.

When the restoring mechanism 16 is tending to move the cylinder means 2 in a draft direction, i.e., restore the unit from a buff condition the pressure differential acting across the valve 140 will not be sufficient to overcome the biasing influence of the spring 1411. Thus, the valve 137 will remain open during the restoring action of mechanism 16 so as to provide a relatively low level of impedance operating against the piston 6 during the restoring action. This relatively low level of impedance will tend to ensure that the mechanism 16 is operable to effect rapid restoration of the cylinder means 2 to its neutral position.

It will also be appreciated that during run-out train action phenomena, once the piston means 6 has moved" relative to the cylinder wall 25, so as to have cleared the series of exponential ports 33 through 9 1, an abrupt intensification of im pedance will result because of the highly constricted nature of the port 135 and the closing of the port 136 by the valve 137. This impedance is further intensified when the piston 6 has moved" relative to the cylinder wall 25 so as to have moved past the port 135. Once the port 135 has been cleared, virtually the only flow out of the cavity 711 will be effected by leakage through the closed valve 137, by leakage around piston 6 between the cavities 7a and 7b, and by other highly constricted leakage paths.

OVERALL MODE OF OPERATION OF IMPEDANCE SYSTEM During coupling action, the disabling means of the valve mechanism 16 will maintain the ports 83 through 88 in an open conditionv This will resuit in the entire series of exponentially spaced ports 33 through 94 remaining open. These open ports will yield a substantially or generally linear dissipation of impact energy, with a relatively low impedance level present in cavity 7a,

Once coupling has been effected, with the cars involved being at a substantial standstill, relatively rapid restoration of the unit 1 is effected by mechanism 16 as a result of the control valve 137 remaining open.

With a train in motion, run-in events are controlled by all or some of the ports 33 through 941, and 135. The port 136 will play little or no part in the control of run-in" phenomena, since this port will be covered by the piston 6 when the cylinder means 2 is in the extreme draft position.

Of this group of ports, 83 through 94, and 135, those disposed between the piston face 6!; and the cylinder head 38 during a run-in" event will control the impeding of piston movement. This impedance will be of a relatively high magnitude as a result of the closing of the valves 96 in response to run-in" induced forces.

During run-out train action events, it is anticipated that the ports and 136 will play the primary governing role. In this connection, it will be recalled that the neutral position for the mechanism 1 positions the piston face 6a in juxtaposition with the draft extremity 211 of the cavity 7. It thus is anticipated that the slack developed as a result of train movements will position the piston means 6 in an intermediate position within the cavity where impedance is controlled by the ports 135 and 136. However, it is apparent that some of the ports 83 through 94 in the exponential series may play a role in this impedance if they are located between the piston face 6a and the piston extremity 211 during the run-out event.

Regardless of the position of the piston at the commencement of the run-out event, the piston will move relatively rapidly to a position where control is influenced by the ports 135 and 13d. At least by this point in time, the pressure within the zone 7b will be sufficient to close the valve 137 and create a high hydraulic impedance within the cavity 7b, operable to resist draft movement of the cylinder means 2.

Thus, during run-out" events, if the piston 6 commences movement from the full buff position shown in FIG. 2, three stages of progressively intensifying impedance will develop in the cavity 712. During the first stage, at least some of the ports in the exponential series will provide escape paths for fluid and thus provide the lowest level of impedance in this threestage phenomena. As draft movement of the cylinder means 2 continues, the piston 6 will move through the exponential series and then be controlled, in the second impedance stage, by the port 135 and the port 136. It is contemplated by the time the piston e clears the exponential series, the valve 137 will have closed the port 136. Thus, during this second stage, the relatively restricted escape path provided by the port 135 will afford a higher impedance level.

Continued draft movement of the cylinder means 2 will cause the piston 6 to clear or move past the port 135 so that, in essence, system leakage or bypassing provides the only escape for fluid from the cavity 7b. This leakage or bypassing will pro vide the third or highest level of impedance during the run out" event.

GENERAL MODE OF INSTALLATION OF CUSHIONING MECHANISM By reference to FIG. 1, the mode of interconnection of the cushioning mechanism 1 with the drawbar 15 and the railway car sill 111 will be evident.

The housing 13 is welded in place within the sill 111, as previously described and as illustrated in FIG. 12.

Thereafter, the piston end of the cushioning mechanism 1 is inserted through the opening in the sill mouth 13a. The

cushioning mechanism 1 is moved longitudinally through the sill so as to slide the bearing assembly 12 through the aperture 76 and into abutting engagement with the stop 74a. The securing plate 77 is then installed so as to effectively anchor the piston means to the sill 10.

The coupler bar 15 is inserted into the recess in the connecting means 14. A conventional coupler key 150 is inserted, in sequence, through a slot 151 in vertical wall 152 of connecting means 14, a slot 153 in drawbar l5, and a slot 54 in vertical wall 155 of connecting means 14. With the key 15) thus installed, drawbar 15 is connected with cylinder means 2. In the usual fashion, key 150 will pass loosely" through slot 153 so as to permit horizontal pivoting movement of drawbar 15 relative to cylinder means 2.

During the installation, the plate 22 is connected to the underside of the sill 10 so as to provide a floor operable to slidably support the cylinder means 2 of the cushioning mechanism 1.

Either before or after the installation of the drawbar 15, the restoring mechanism 16 is connected to the sill floor 22. The mechanism 16 is connected with the tongue portion 17 of the cylinder means 2 in the manner generally described in the Abbott US. Pat. No. 3,233,747.

SUMMARY OF ADVANTAGES AND SCOPE OF lNVENTlON A major advantage of the invention resides in the ability of the run-in" control valve to provide an immediately effective, low impedance level in the hydraulic cushioning device capable of effectively absorbing buff coupling shock. The low level forces acting on the cushioning device during run-in" train action events, are controlled by the valve member moving to a closed valve position.

The immediately effective, open passage condition of the valve, which serves to control buff coupling forces, results from a unique combination of the normally open valve and the low inertia disabling sleeve which moves almost instantaneously to obviate the valve closing influence of the annular fluid reaction piston 104.

The telescoping relationship of the valve 99 and the sleeve 121 provides axially overlapping operating paths for these components so as to minimize the axial dimension of the control valve 96 and facilitate its positioning between the low pressure and high-pressure cylinder walls of the cushioning device.

The use of cylindrical components and a single actuating spring in the valve contributes to ease of manufacture and structural and operational reliability.

The use of the cylindrical lip 130, in combination with the valve 96, which prevents the accidental introduction of the cylindrical valve components into the interior of the highpressure cylinder, yields a significant safety factor.

in the past, it has been suggested that excessive pressure responsive, relief valves may be provided in hydraulic cushioning devices so as to prevent the development of excessive pressures. However, the inertia of such relief valves, and the conventional biasing associated with them, inherently provides a relatively high impedance level for the dissipation of impact or coupler shocks, in direct contradistinction to the low impedance provided in the present invention for absorbing such impact or coupler shocks.

Further, the low impedance level of the present invention is immediately effective to absorb impact energy where relief valve systems inherently involve an operational delay, during which there is a danger of developing excessive hydraulic pressures.

Further, vent valves systems have an inherent propensity to provide undesirably high impedance in response to low-level, coupling action induced impact forces. Thus, during such lowlevel coupling action, the vent valve systems tend to produce excessive impedance, so as to transmit excessively severe shock forces to the body of a railway car.

The unique utilization ofrunin control valves in association with an exponential series of ports provides a mechanism operable to effect a generally linear dissipation of impact energy with no operational delay and yet be fully responsive to run-in" train action events so as to control and limit the severity of this phenomena.

A highly significant aspect of the invention involves the provision of a comprehensive system including the unique run-in control valve, which enables a cushioning mechanism to effectively absorb coupler shocks, effect rapid restoration, and yet provide high impedance levels for controlling both run-in" and run-out" train action phenomena.

in describing the invention, reference has been made to preferred embodiments. However, those skilled in the railway cushioning art and familiar with the disclosure of this invention may envision additions, deletions, modifications and substitutions which fall within the purview of the art as defined in the appended claims.

lclaim:

l. A valve for controlling the impedance level in an hydraulic-type train cushioning device, said valve comprising:

valve means biased to a normally open condition and operable to provide immediately effective fluid communication between a high-pressure impedance zone of a cushioning device and a fluid receiving means;

actuating means operable to move said valve means to a position tending to impede flow between said impedance zone and said fluid receiving means in response to runin," train action forces acting on said cushioning device; and

valve disabling means, operable in response to buff coupling forces acting on said cushioning device, to disable said actuating means and maintain said valve means in a substantially open condition.

2. A valve for controlling the impedance level in hydraulictype railway cushioning devices, said valve comprising:

body means;

passage means extending through said body means and operable to provide fluid communication between an hydraulic impedance zone of a railway-cushioning device and a low-pressure fluid discharge zone of said cushioning device:

a valve member mounted for telescoping movement in said body means and operable to control flow through said passage means;

fluid reaction means operable to cause said valve to move to a position impeding flow through said passage means in response to flow from said impedance zone to said lowpressure fluid discharge zone;

port means providing fluid communication between said passage means and said fluid reaction means;

valve disabling means operable to tend to close said port means in response to a rate of movement of a railway coupling member, connected with said cushioning device, which rate of movement results from buff coupling forces acting on said coupling member; and

biasing means resiliently urging said valve member to an open position operable to permit fluid flow through said passage means.

3. A valve for controlling the impedance level in hydraulictype railway cushioning devices, said valve Comprising:

generally cylindrical body means;

passage means extending through said body means and operable to provide fluid communication between an hydraulic impedance zone of a railway cushioning device and a low-pressure fluid discharge zone of said cushioning device;

a cylindrical valve member mounted for telescoping movement in said body means and operable to control flow through said passage means, said valve member including a fluid reaction surface traversing said passage means,

and

first port means between said reaction surface and said impedance zone providing communication between said passage means and said discharge zone; annular piston means connected with said valve member and operable to cause said valve to move to a position impeding flow through said passage means in response to flow from said impedance zone to said low-pressure discharge zone: second port means providing fluid communication between said passage means and said annular piston means: sleeve means operable to tend to close said second port means in response to a rate of movement of a railway coupling member, connected with said cushioning device, which rate of movement results from buff coupling forces acting on said coupling member, which buff forces induce a rate of movement of said coupling member exceeding the rate of movement responsive to run-in forces; and

coil spring means resiliently urging said valve member to a position operable to permit fluid flow through said passage means and urging said sleeve means away from said second port means;

mounting means operable to secure said valve member to the exterior of a cylinder wall housing said impedance zone; 7

retaining means operable to prevent movement of said valve member and said sleeve means through said cylinder wall into said impedance zone:

said sleeve means being characterized by lower inertia than said valve member.

Claims (3)

1. A valve for controlling the impedance level in an hydraulictype train cushioning device, said valve comprising: valve means biased to a normally open condition and operable to provide immediately effective fluid communication between a high-pressure impedance zone of a cushioning device and a fluid receiving means; actuating means operable to move said valve means to a position tending to impede flow between said impedance zone and said fluid receiving means in response to ''''run-in,'''' train action forces acting on said cushioning device; and valve disabling means, operable in response to buff coupling forces acting on said cushioning device, to disable said actuating means and maintain said valve means in a substantially open condition.

2. A valve for controlling the impedance level in hydraulic-type railway cushioning devices, said valve comprising: body means; passage means extending through said body means and operable to providE fluid communication between an hydraulic impedance zone of a railway-cushioning device and a low-pressure fluid discharge zone of said cushioning device: a valve member mounted for telescoping movement in said body means and operable to control flow through said passage means; fluid reaction means operable to cause said valve to move to a position impeding flow through said passage means in response to flow from said impedance zone to said low-pressure fluid discharge zone; port means providing fluid communication between said passage means and said fluid reaction means; valve disabling means operable to tend to close said port means in response to a rate of movement of a railway coupling member, connected with said cushioning device, which rate of movement results from buff coupling forces acting on said coupling member; and biasing means resiliently urging said valve member to an open position operable to permit fluid flow through said passage means.

3. A valve for controlling the impedance level in hydraulic-type railway cushioning devices, said valve comprising: generally cylindrical body means; passage means extending through said body means and operable to provide fluid communication between an hydraulic impedance zone of a railway cushioning device and a low-pressure fluid discharge zone of said cushioning device; a cylindrical valve member mounted for telescoping movement in said body means and operable to control flow through said passage means, said valve member including a fluid reaction surface traversing said passage means, and first port means between said reaction surface and said impedance zone providing communication between said passage means and said discharge zone; annular piston means connected with said valve member and operable to cause said valve to move to a position impeding flow through said passage means in response to flow from said impedance zone to said low-pressure discharge zone: second port means providing fluid communication between said passage means and said annular piston means: sleeve means operable to tend to close said second port means in response to a rate of movement of a railway coupling member, connected with said cushioning device, which rate of movement results from buff coupling forces acting on said coupling member, which buff forces induce a rate of movement of said coupling member exceeding the rate of movement responsive to run-in forces; and coil spring means resiliently urging said valve member to a position operable to permit fluid flow through said passage means and urging said sleeve means away from said second port means; mounting means operable to secure said valve member to the exterior of a cylinder wall housing said impedance zone; retaining means operable to prevent movement of said valve member and said sleeve means through said cylinder wall into said impedance zone: said sleeve means being characterized by lower inertia than said valve member.

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