US3713546A

US3713546A - Cushioning arrangement for railroad cars

Info

Publication number: US3713546A
Application number: US00091383A
Authority: US
Inventors: D Daugherty
Original assignee: Cardwell Westinghouse Co
Current assignee: Trane US Inc; Cardwell Westinghouse Co
Priority date: 1970-11-20
Filing date: 1970-11-20
Publication date: 1973-01-30
Anticipated expiration: 1990-01-30
Also published as: FR2114910A5; GB1374477A; ZA717383B; AU3529671A; AU442210B2; BR7007717D0; CA944316A; DE2157316A1; BE775584A; IT941214B

Abstract

A cushioning arrangement for railroad cars that is of the ''''end of car'''' cushioning type and includes a hydraulic cylinder keyed to the car fixed center sill against buff and draft forces and having its piston rod secured to a slidably mounted coupler adapter member having flanges projecting from either side of same that each carry a resilient draft impact absorbing cushion that cooperates with fixed draft stops. A compression spring acts between the hydraulic cylinder and the adapter member to bias the ram to its neutral position after a buff stroke, and the adapter member flanges engage over solid buff limiting stops at the end of the buff stroke. The hydraulic cushion includes a combined programmed metering-pressure sensitive orifice and control arrangement that insures needed control over the ram to overcome train line tendencies.

Description

1 1 Tan. 30, 1973 [54] CUSHIONING ARRANGEMENT FOR RAILROAD CARS David W. Daugherty, Jr., Downers Grove, Ill.

[75] Inventor:

[73] Assignee: Cardwell Westinghouse Company [22] Filed: Nov. 20, 1970 [21] Appl.No.: 91,383

[52] US. Cl. ..213/43, 188/314, 188/317, 213/8, 267/65 R [51] Int. Cl. ..B6lg 9/08, B61g 9/16 [58] Field of Search ..213/8, 43; 267/64 A, 65; 188/313, 314, 317

[56] References Cited UNITED STATES PATENTS 3,633,763 1/1972 Peterson ..213/43 3,150,783 9/1964 Campbell et a1. ..213/43 3,257,000 6/1966 Cope ..213/8 3,411,635 11/1968 Powell ..213/43 3,554,387 1/1971 Thornhill ..213/43 3,173,552 3/1965 Zanow ..213/43 3,400,833 9/1968 Powell ..213/43 Peterson ..213/43 Peterson ..213/43 Primary ExaminerDrayton E. Hoffman Attorney-Mann, Brown, McWilliams & Bradway [57] ABSTRACT A cushioning arrangement for railroad cars that is of the end of car cushioning type and includes a hydraulic cylinder keyed to the car fixed center sill against buff and draft forces and having its piston rod secured to a slidably mounted coupler adapter member having flanges projecting from either side of same that each carry a resilient draft impact absorbing cushion that cooperates with fixed draft stops. A compression spring acts between the hydraulic cylinder and the adapter member to bias the ram to its neutral position after a buff stroke, and the adapter member flanges engage over solid buff limiting stops at the end of the buff stroke. The hydraulic cushion includes a combined programmed metering-pressure sensitive orifice and control arrangement that insures needed control over the ram to overcome train line tendencies.

9 Claims, 11 Drawing Figures PATENTED JAN 3 0 I973 SHEET 1 BF 5 INVENTOR P Y T m m m.

i W W! W D PATENTEDJANSOIBIS 3.713.546

sum 2 0r 5 IN VENTOR DAVID W DAUGHERTKJR PATENTED JAN 30 I975 SHEET 3 OF 5 L I26 v INVENTOR DAVID W DAUG-ERTY, JR.

" B ATT'Y CUSHIONING ARRANGEMENT FOR RAILROAD CARS This invention relates to a cushioning arrangement for railroad cars of the end of car cushioning type, and more particularly, relates to improvements over the end of car cushioning arrangements disclosed in my applications Ser. No. 718,551, filed Apr. 3, 1968 and Ser. No. 803,531, filed Mar. 3, 1969, now U.S. Pat. Nos. 3,542,212 and 3,534,870, respectively.

The cushioning arrangements of my said applications are of the two way or double acting type that cushion both in draft and buff, in which a piston or ram head moves within a cylinder closed at either end, with the ram extending out of the rod end of the cylinder for connection to a slidably mounted coupler adapter member to which the coupler is connected. The ram head defines two separate chambers within the cylinder and includes a two way check valve that acts to permit hydraulic liquid flow from the high to the low pressure chamber during cushioning, with the hydraulic liquid flow being directed through a pressure sensitive orifice arranged to serve as the primary means for controlling pressure in the high pressure chamber during normal operations. In one arrangement, a rubber pad type resilient cushioning device is interposed between the hydraulic cylinder and the car to provide for draft shock absorption of the conservative energy type when draft impacts are occasioned with the piston disposed adjacent the draft end of the cylinder.

One of the long-standing problems in the railroad field in connection with end of car type cushioning devices has been the difficulty of providing control over tendencies of cars in a train to run in and run out (which actions are commonly referred to as train line action).

The principal object of this invention is to provide an end of car cushioning arrangement which insures full control over train line action of a car equipped with same and at all points of cushion travel provided by the cushioning unit involved.

Another principal object of the invention is to provide a cushioning arrangement in which resilient or conservative energy type cushioning acts in parallel with hydraulic cushioning means in handling draft impacts acting to move the hydraulic unit piston in the draft direction from its neutral position, with-the piston being adequately spaced from the end of the cylinder at the end of the draft stroke to avoid applying undesirable forces to that end of the cylinder.

Other important objects of the invention are to provide a combined programmed metering and pressure sensitive orifice control arrangement for hydraulic cushioning devices, to provide adequate conservative energy type draft cushioning in the limited space available for same at the end of the car, without increasing the overall length of the cushioning arrangement involved, and to provide a hydraulic cushioning arrangement that is economical of manufacture, convenient to install, and long lived in operation.

In accordance with this invention, the hydraulic cylinder is keyed to the car fixed center sill at its inner end against buff and draft forces, and has its piston rod or ram secured to a slidably mounted coupler adapter member positioned adjacent the outer end of the car cushioning gear pocket, which adapter member is equipped with laterally and outwardly extending flanges each carrying a rubber pad type draft cushioning device that respectively cooperate with fixed draft stops for draft cushioning purposes when the piston is moved in draft from its neutral position. A compression spring acts between the unit hydraulic cylinder and the adapter member to bias the ram piston to its neutral position after a buff stroke, and the adapter member flanges engage over solid buff limiting stops at the end of the buff stroke. The hydraulic cushion itself includes a combined programmed metering-pressure sensitive orifice control arrangement that operates at all positions of the cushion piston relative to its cylinder to insure that the needed control over the ram piston movements to avoid undesirable train line action is effective over the full range of travel of the cushion.

Other objects, uses and advantages will be obvious or become apparent from a consideration of the following detailed description and the application drawings in which like reference numerals indicate like parts throughout the several views.

In the drawings:

FIG. 1 is a diagrammatic two position plan view, partially in horizontal section, through one end of a railroad car equipped with the cushioning arrangement of this invention, with the upper half of the view showing the cushioning device in its neutral position and the lower half of the view showing the cushioning device in its full buff travel position;

FIG. 2 is a vertical section view substantially along line 2-2 of FIG. 1, showing the cushioning device in its neutral position;

FIGS. 3, 4, 5, 6 and 7 are fragmental cross-sectional views taken substantially along lines 3-3, 4,4, 55, 6-6, and 77, respectively, of FIG. 1;

FIG. 8 is a fragmental enlarged sectional view through the draft end of the hydraulic unit and associated parts showing the ram piston at its full draft travel position relative to the cylinder;

FIG. 9 is a fragmental sectional view illustrating on an enlarged scale the valve member that forms the pressure relief valve in the ram head or piston shown in FIG. 8;

FIG. 10 is similar to FIG. 1 but illustrates the invention arranged for a type F coupler application; and

FIG. 11 is similar to FIG. 2 but shows the embodiment of FIG. 10.

However, it is to be distinctly understood that the specific drawing illustrations provided are supplied primarily to comply with the requirements of the Patent Code, and that the invention may have other embodiments that will be obvious to those skilled in the art and that are intended to be covered by the appended claims.

GENERAL DESCRIPTION Reference numeral 10 of FIGS. 1 and 2 generally indicates a cushioning arrangement in accordance with this invention applied to the end 12 of a railroad car 14 for the purpose of providing end of car cushioning between the car and its coupler 16.

The only portion of the car 14 that is shown is its fixed center sill 18, which may be of the usual channel shaped configuration and formed to define at one end 20 of same a pocket 22 for receiving the cushioning arrangement l0.

The cushioning arrangement generally comprises hydraulic unit 24 including cylinder 26 having its inner or head end 28 suitably keyed to center sill 18, as by being applied to the lug structure 30 that is suitably affixed to the center sill 18. Mounted within the cylinder 26 is a piston or ram head 32 dividing the interior of the cylinder 26 into

variable volume chambers

34 and 36 on either side of the head 32. Head 32 is affixed to ram shank 38 which extends outwardly of the cylinder 26 along its longitudinal axis and through its outer or rod end 40 for connection to a coupler adapter or sliding box member 42 slidably mounted at the forward end of pocket 22. The adapter member 42 is connected to the shank 44 of the coupler 16 by a suitable key 46 (shown in phantom in FIG. 1

The coupler adapter member 42 is formed to define a pair of flanges or ears 48 and S0 projecting in opposite directions laterally of the pocket 22, which flanges or

ears

48 and 50 each carry a rubber pad type cushioning device 52 and 54 that respectively abut against fixed sill stops 56 and 58 to provide cushioning in draft when the coupler 16 is subjected to a draft impact when the piston 32 is in the neutral position shown in the upper portion of FIG. 1.

Interposed between a spring seat 60 and the adapter member 42 is a high strength compression spring 62 which acts as the return spring for the hydraulic cylinder 24. In the form shown, the ram stem 38 extends through inner wall 64 of the adapter member 42 and is held in place by a threadably mounted cap 66 against the rim 68 of which the wall 64 abuts under the action of spring 62 to apply the bias of the spring 62 to ram shank 38 and thus ram head 32. The coupler shank 46 abuts against the cap 66 on buff impacts; thus the cap 66 serves as a buff impact block for transmitting buff impacts to ram stem 38 and adapter member 42.

The hydraulic cushioning device 24 (see FIG. 8) includes a double acting check valve 70 and pressure relief valve 72 that serve the same general functions as their corresponding valves described in my said applications, as well as the boot 74 that provides the reservoir 76 for hydraulic liquid displaced from chamber 36 by the entry of the ram stem 38 into cylinder 24 during the buff stroke of the hydraulic cushioning device.

In accordance with this invention, hydraulic cushioning device 24 is arranged to provide a combined programmed metering-pressure sensitive orifice control arrangement generally indicated by reference numeral 78, which comprises pressure sensitive valve 80 operably associated with the central orifice 82 of the piston or ram head 32 for the purpose of blocking off hydraulic liquid flow between orifice 82 and ram head passages 84 until a predetermined pressure has built up in either of the

chambers

34 or 36. Extending longitudinally of the hydraulic cushion device 34 is a fixed metering pin 86' having its external surface 88 contoured to provide the force travel characteristics that may be desired as the ram head 32 moves towards cylinder end 28 as the cushioning arrangement absorbs a buff impact from the neutral position of FIG. 1. The programmed metering provided by pin 86 and valve 80 cooperate in series to provide the cushioning action hereinafter described.

Pressure relief or safety valve 72 (see FIG. 8) functions to permit hydraulic liquid to pass from chamber 34 to chamber 38 in the event that pressures in chamber 34 rise to predetermined levels (for instance 13,000 psi in a commercial embodiment) that warrant pressure relief for safety purposes.

The arrangement 10 is arranged to accommodate type E couplers while the arrangement 10A of FIGS. 10 and 11 is arranged to accommodate type F couplers. Arrangement 10A is otherwise substantially identical to arrangement 10.

The normal riding or neutral position of the cushion arrangement 10 is shown in the upper half of FIG. 1, with the piston ram head 32 spaced from cylinder end 40. In a commercial form of the invention, the arrangement is such that the spacing of the head 32 from the cylinder end 40 is about an inch and a quarter in the neutral position indicated and the rubber pad cushioning devices 52 provide a draft cushion travel of about one inch,.with the result that the ram or piston head 32 never contacts the cylinder end 40.

When buff impacts are occasioned, the coupler shank 46 engages cap 66 to thrust the ram shank 38 and coupler adapter member 42 to the right of FIG. 1, thereby causing ram head 32 to apply pressure on the hydraulic liquid in chamber 34 and thus causing double acting check valve to close to preclude the passage of hydraulic liquid therethrough to chamber 36 or reservoir 76. However, little or no relative movement of the piston head and thus the ram and coupler shank, occurs, relative to the hydraulic cylinder 26, until the pressure within the chamber 34 builds up to the point that the pressure sensitive valve opens to permit hydraulic liquid discharge through orifice 82 and passages 84. In a commercial form of the invention, this level lies in the range of from about 1,000 psi to about 2,500 psi of pressure acting on the high pressure side of the ram head, or terms of coupler pressure, in this range of from about 35,000 lb. to about 65,000 lb.

After the orifice control valve 80 opens, the cushion travel of the ram head 32 towards the cylinder end 28 proceeds, with the contoured surface 88 of metering pin 86 acting in accordance with well known cushioning principles to provide the force travel characteristic desired. The surface 88 is preferably contoured to provide substantially constant force travel closure characteristics, but the exact contour employed will depend on particular type of force travel characteristics that are desired by the designer, and will be effected to some extent by the presence of valve 80. The combined effect provided by orifice control valve 80 and programmed metering pin 86 enables close approach to desired cushioning efficiency.

The buff travel stroke of the hydraulic cushioning arrangement 10 is limited by the

flanges

48 and 50 engaging the respective over-travel stops 57 and 59, if that much travel is required to absorb the buff impact. In any event, when the buff impact is dissipated, valve 80 closes, and remains closed until again opened by forces acting in either

chamber

34 or 36 that are in the range indicated. However, the return spring 62 restores the parts to the neutral position indicated in FIG. 1, with the liquid flow past ram head 32 being by way of low volume flow snubbing rate seepage past the ram head by reason of normal tolerance variations. The neutral position is set by the elongate bolt and canister assemblies 63 (see FIGS. 6 and 8) which interconnect the coupler adapter 42 and the spring seat 60 at the four corners of the pocket 22, and the restorative action of cushions 52 and 54.

When draft impacts are occasioned, the coupler 16 moves to the left of FIG. 1 to draw draft key 46 against draft lugs 90 of the coupler adapter member 42 which results in the ram shank 38 being drawn to the left of FIG. 1 by virtue of the engagement of adapter member wall 64 with cap 66, as soon as valve device 80 opens at the predetermined pressure level dictated by the design of the orifice control valve 80. The ram head 32 and

flanges

48 and 50 of the coupler adapter 42 then cause the hydraulic cushion device 24 and rubber pad cushions 52 and 54 to act in parallel to absorb the draft impact, spring seat 60 and spring 62 being drawn to the left relative to the cylinder 26 by virtue of the connection of the bolt and canister assemblies 63 to the spring seat 60. After the draft impact has been dissipated, rubber pad devices 52 and 54 restore the cushioning arrangement to the neutral position of FIG. 1.

It will thus be apparent that this invention provides several important advantages.

In the first place, the pressure sensitive orifice control valve 80 provides control over movement of the ram relative to the hydraulic cylinder up to the pressure levels that will open valve 80 and at any position it might be between either end of cylinder 26. This operates to oppose tendencies of the coupler 16 to move in the usual train line action manner when run in and run out forces are imposed on the coupler, regardless of whether such forces are occasioned by cross country travel or travel around curves, or the like. As indicated, this control is available at all points of travel of the unit as valve 80 moves with head 32. When forces within the chamber 34 and chamber 36 (depending upon which chamber is being contracted by the cushioning action involved) are reduced to levels permitting valve 80 to close, hydraulic liquid flow through orifice 82 is precluded and ram head return to neutral is achieved under the biasing actions provided by return spring 62 and resilient cushioning devices 52 and 54, with the necessary hydraulic displacement being achieved through seepage past ram head 32. On the other hand, when either the buff or draft impacts involved do apply sufficient pressure on the hydraulic liquid in one of the indicated cylinder chambers, valve 80 opens to permit hydraulic liquid flow in the usual manner through orifice 82.

It will also be noted that the inner end of the hydraulic cylinder 26 is fixed against movement relative to the sill l8 and the draft cushioning that is provided is effected in part by conservative energy type cushioning devices at the forward or outer end of the cushioning pocket 22, which are disposed to one side of the longitudinal axis of the unit so that they do not add to the length of same or play any part in absorbing buff impacts.

SPECIFIC DESCRIPTION The fixed center sill 18 that is illustrated is intended to represent any suitable conventional type of center sill, one common form of which comprises the channel shaped member 100 defining spaced

side walls

102 and 104 separated by top wall 106, with the

walls

102 and 104 being suitably flanged as at 108. In the form shown, the

sill walls

102 and 104 are terminated short of the end 12 of the car 14, as at 110, and have affixed thereto the respective

upright plates

112 and 1 14 that form the over

solid stops

57 and 59, respectively, which plates 112 and 114 are suitably reinforced by vertically spaced webs 116. Fixed between the respective plates 112 and 114 and the end 12 of the car are suitable lon gitudinally extending

plates

118 and 120 to which the

respective stop plates

122 and 124 of the respective sill stops 56 and 58 are affixed as by welding.

Plates

118 and 120 are suitably reinforced by suitable webs 126 extending between same and the sill 18, and plates 122 are suitably reinforced by the

plate structures

130 and 132 that are indicated in FIG. 4, and which are affixed to the

respective stop plates

122 and 124, as by weldmg.

The sill pocket 22 is suitably closed from above and below by suitable top and

bottom plates

136 and 138 affixed in place in any suitable manner, as well as the top wall 106 of sill 18 inwardly of over

solid stops

57 and 59. Top plate 136 carries guide plate 137 above adapter members 42.

The lug structure 30 that keys the inner end 28 of the cylinder 26 to sill 18 is shown in the form of a U-shaped casting 140 having its

side walls

142 and 144 suitably reinforced by

webs

146 and 148 and affixed to the

walls

102 and 104 of the sill 18 in a suitable manner, as by employing rivets or the like. The casting 140 is shaped to define a central slot 150 that is vertically disposed and opens downwardly when the casting 140 is mounted in its operating position, as indicated in FIGS. 1 and 2, to receive the end 28 of cylinder 26.

The spring seat 60 normally seats against shoulder 152 of the cylinder under the action of spring 62, but as indicated, the spring seat 60 moves to the left of FIG. 1 relative to the cylinder when draft impacts are occasioned at a time the cushioning unit is in its neutral position of FIG. 1.

The coupler adapter member comprises a hollow box-shaped structure defining top wall 162,

side walls

164 and 166, and bottom wall 168, as well as transverse wall 64 which is formed with opening to receive the ram stern 68. At its outer end 172 member 42 is provided with two transversely extending upright flanges 174 on which is suitably mounted a wear plate 176 on which the coupler shank 46 rides.

Side walls

164 and 166 are formed with the

respective openings

178 and 180 between which extends the coupler key 46, which in the form shown is held in place by the respective latch bars 182 and 184 removably secured in place by screws or the like. Member 42 is internally flanged as at 186 for reinforcing purposes, the flanges being suitably contoured as at 188 to permit cap 66 to be rotated for applying or removing the ram shank relative to the member 42.

Flanges

48 and 50 are integral with

respective side walls

164 and 166 of the member 42, and as indicated in FIG. 1, they are formed with suitable bolt receiving holes 190 that receive the respective mounting bolts 192 that secure the respective rubber pad cushioning devices 52 and 54 thereto.

The rubber pad cushioning devices 52 and 54 are identical in construction and may be of any suitable specific construction of the so-called rubber pad type. In the form shown, they comprise urethane pads 194 suitably bonded to steel plates 196 in an alternating manner with the bolts 192 passing through the alternating pads and plates for threaded engagement with abutment plate 198 that engages the

respective stop plates

122 and 124 when the cushioning devices 52 and 54 are acting to absorb draft impacts. As indicated in FIG. 5, there are two pairs of bolts 192 and corresponding bolt holes 190 for each unit 52 and 54.

The adapter member 42 at its inner end 173 is formed to define spring seat 200 against which spring 62 seats in the manner indicated in FIGS. 1 and 2.

The movement of adapter member 42 longitudinally of sill 18 is guided by

plates

118, 120 and 133.

The bolt and canister assemblies 63 each comprise a tubular canister 202 (see FIG. 8) having a flared open end 204 of same seated in recess 206 of the spring seat 60 (at one corner of same) with respective canisters extending through opening 208 of the spring seat toward the end 173 of the adapter member 42. The canisters 202 define a bore 210 that is flanged as at 212 at the respective ends 214 thereof to serve as an abutment for the heads 216 of the respective bolts 218 which extend from the canisters 22 into threaded engagement with the end 173 of the adapter member 42. The bolt and canister assemblies 63 are adjusted so that when the bolt heads 216 engage the flanges 212 of each device 63, under the action of spring 62, piston 32 will be in the neutral position shown in FIGS. 1 and 2 and abutment plates 198 will be spaced approximately oneeighth of an inch from

stop plates

122 and 124, respectively.

Hydraulic cylinder 26 comprises a cylindrical side wall'220 closed by integrally united end wall 28 which is flanged as at 222 for keying application to slot 150 of lug structure 140. End 40 of cylinder 26 is formed by a wall 224 that is proportioned to substantially complement the internal surface 226 of side wall 220 and is held in place by holding ring 228 (see FIG. 8) that is threadedly received within the side wall 220 at its end 230 and against the wall 224 to press its shoulder 232 against the shoulder 234 of the side wall 220. Wall 224 is suitably recessed as at 236 and 238 to receive the respective O-ring seals 240 and 242 that are in sealing engagement with the surface 226 of side wall 220.

The ram head 32 and ram stem 38 in the form shown are integrally united to form a ram 35. At the ram head end 250 of the ram 35, the ram is formed with pressure sensitive orifice chamber 252, at one end 254 of which is seated ring 256'which forms orifice 82, which ring 256 is held in place by a suitable lock ring 258. Chamber 252 is formed to define smooth surfaced cylindrical wall 260 which has in sliding relation therewith sleeve member 262 forming the major component of valve 80, that has its outer surface 264 proportioned to substantially complement the surface 260. Sleeve 262 is biased against orifice ring 256 by suitable compression spring 266 that acts on the end 268 of the sleeve 262 to bias its other end 270 against the orifice ring 256.

The ram head end 250 of ram 35 is formed with a plurality of equally spaced passages 84 (though only one is shown) that communicate between the chamber 252 and chamber 36 when sleeve 262 is moved to the left of FIG. 8 under the action of the indicated predetermined pressure in either

chamber

34 or 36. In this connection, it has been found that the oil film which in practice will exist between sleeve end surface 271 and orifice ring surface 273 (which defines the valve seat against which sleeve surface 271 acts) sufficiently separates these surfaces so that the indicated pressure build ups on the high pressure side of the ram head (whether acting in buff or draft) will be operative to deflect sleeve 262 to open valve 80. Sleeve end surface may be rounded to reduce the strength of spring 266 that is required without reducing the thickness of sleeve 262.

The ram 35 is formed along its longitudinal axis with bore 280 that receives the metering pin 86 as the hydraulic cushion acts to absorb impacts in buff. Orifice bushing 282 is threadedly mounted at the end 284 of bore 280 and extends through spring 266 into guiding relation with the bore defining surface 286 of sleeve 262.

As indicated in FIG. 8, the bushing 282 is shouldered as at 288 to provide the indicated guiding relationship to the sleeve 262, and shoulder 288 and surface 286 are in substantial complemental engagement for liquid seal purposes.

The metering pin 86 extends through orifice 82 and orifice chamber 252 in alignment with the bore 280. The metering pin at its end 290 is provided with bushing 292 held in place by suitable mounting pin 294 for antifriction cooperation with the surface 296 that defines bores 280 and inner surface 297 of bushing 282 at the end of the buff stroke. At its other end 295 the metering pin is threaded as at 298 for threaded application to the end 28 of cylinder 26.

The ram head 32 is formed with passage 300 at one side thereof that receives the double headed valve member 302. The ends 304 and 306 of the valve member 302 are suitably contoured for sealing engagement with the

respective valve seats

308 and 310 formed in the ram head. In the form shown, valve head 306 is integral with stem 312 and is slotted as at 314 for threaded engagement with head 304 so that adjustment of the spacing between

heads

304 and 306 may be readily made to provide the operating characteristics desired.

Ram head 32 is also formed with cross passage 320 and it connects passage 300 with the passage 322 that extends longitudinally of the ram and leads to communication with the reservoir 76. In the form shown, the passage 322 terminates in cross passage 324 which connects the bore 280 to the reservoir 76. Flow deflector 326, secured in place by suitable pins 327, protects the boot 74 from hydraulic flow that is not parallel thereto.

The portion of the orifice chamber 252 in which the spring 266 is mounted is connected to passage 322 by cross bore 328 to insure that spring 266 operates in a low pressure area. Bore 328 is closed by suitable plug 330 at the outer side wall of the ram. Passage 322 is closed by suitable plug 332 at the face 334 of the ram.

The ram head 32 is recessed as at 336 to receive suitable bushing 338 that is in smooth sliding relationship with the surface 226 defined by the cylinder side wall 220.

The boot 74 in forming reservoir 76 is connected to cylinder wall 224 at its end 340 by suitable lock ring 342, and to the ram at its end 344 by suitable lock ring 346. End wall 224 is formed with a suitable passage 348 communicating between reservoir 76 and passage 350 of the cylinder side wall 220 for the purpose ofinsuring that the reservoir 76 is suitably fluid filled, which passage 350 is closed by suitable plug 352. Cylinder side wall 220 is also formed with suitable passage 354 for draining purposes, which passage is closed by suitable plug 356.

The boot 74 is formed from any suitable type of resiliently flexible material so that it expands resiliently as the cushion device moves to its full buff closure position, whereby the boot exerts sufficient pressure on the hydraulic liquid within the chamber 76 to bias same toward return tocylinder 26 on the return stroke of the cushion.

The relief valve 72 comprises a passage 360 extending through one side of' ram head 32 in which is mounted valve body 362 flanged as 364 for reception in counter bore 366 formed in the ram head 32 and is held in place by lock ring 368. Body 362 is formed with a plurality of longitudinally extending passages 370 each communicating with a groove 372 formed in the body 362 in its outer cylindrical side wall 374 see FIG. 9) that slidably mounts sleeve member 376 having a stepped diameter inner surface 378 of which surface portion 379 substantially complements the correspondingly formed portion 381 of side wall 374 of the body member 362 for good sealing relationship therewith downstream of groove 372. Sleeve inner surface 37 8 forms an internal annular shoulder 383, that is exposed to groove 372, and surface portion 385 which substantially complements the cylindrical side wall 387 of body 362 for good sealing relationship therewith upstream of groove 372. Sleeve member 376 is formed with a plurality of ports 380 adapted to be brought into simultaneous communication with groove 372 when the pressure in chamber 34 exceeds the safety limit prescribed by the designer, which pressure will act on shoulder 383 to deflect biasing control spring 382 to bring the ports 380 into communication with the groove 372 whereby hydraulic liquid may pass from passages 370 through groove 372 and passages 380 and thence through ram head passage 360 to provide the pressure relief desired. Spring 382 in normal operation biases sleeve member 376 to the position indicated in FIG. 9, which closes off ports 380 from groove 372.

In the form shown, the valve body 362 is formed to define a stem portion 384 over which the spring 382 is received and is held in place by suitable spring seat 386 that is threadedly received on the stem portion 384 and secured in place as by brazing. The arrangement illustrated permits spring 382 to be a relatively light compression spring.

In the cushioning arrangement 10A of FIGS. 10 and 11, the sill 18, the lug structure 30, the cushioning unit 24, including its ram 35, spring seat 60 and spring 62, are the same as described in connection with the embodiment of FIGS. 1 9. Cushioning arrangement 10A is modified principally to accommodate type F couplers and thus the principal changes in structure are concerned with coupler adapter member 42A and the car structure adjacent the outer end of the cushioning pocket 22A.

The coupler adapter member 42A includes a rounded end portion 200A that is substantially identical to the end portion 200 of adapter member 42 and thus is formed with oppositely projecting

flanges

48A and 50A with which the rubber

pad cushioning devices

52A and 54A are associated in a manner identical to that described in connection with the embodiment of FIGS. 1 9. The

cushioning devices

52A and 54A include the alternating rubber pads and

plates

194 and 196 operatively associated with a base plate 198, with the respective base plates 198 engaging

stop structures

56A and 58A respectively on draft impacts in the manner already described. Stop

structures

56A and 58A each comprise upright plates 122A suitably reinforced by spaced web plates 400.

Flanges

48A and 50A respectively also cooperate with over

solid stops

57A and 59A, respectively, each of which comprise the

respective upright plates

112A and 114A suitably reinforced by vertically spaced

web plates

402 and 404 that are fixed between the

respective side walls

102 and 104 of the sill 18 and the respective

sill extension plates

406 and 408 to which the respective upright stop forming

plates

112A, 114A, 122A and 124A are affixed, as by welding.

On either side of the outer end of pocket 22A, a pair of coupler

carrier support members

410 and 412 are mounted which support an arcuate coupler carrier 414 on which rides coupler 416, the shank of which is indicated at 418.

The end 200A of the coupler adapter 42A serves as a spring seat for spring 62, and the member 42A includes transverse wall 64A that is apertured as at 172A to receive the=outer end of the ram shank together with the rim 420 of a cap member 422 that is internally threaded as at 424 to threadedly receive the ram shank end.

The cap member 422 fits against the outer side of wall 64A, and has its end surface spherically contoured as at 426 for abutting cooperation with the spherically contoured end 428 of the coupler shank 418, which is pivoted between the top and

bottom walls

162A and 168A of the adapter member 42A by suitable pivot pin 430 (supported by retainer 431 threaded into member 42A).

As in the case of the embodiment of FIGS. 1 9, the pocket 22A is enclosed at the top by a suitable plate structure 432 and at the bottom by suitable plate structure 434.

The cushioning arrangement 10A functions in a manner similar to that of the arrangement 10 except that the arrangement 10A is of the type to accommodate type F couplers, as indicated. 1

In the illustrated embodiments, the hydraulic cushioning device 24 is arranged to provide fifteen inches of travel in the buff stroke and one inch of travel in the draft stroke. However, these dimensions are optional with the designer and may be varied to suit specific conditions, as may be the force travel characteristics that are employed.

The foregoing description and the drawings are given merely to explain and illustrate the invention and the invention is not to be limited thereto, except insofar as the appended claims are so limited, since those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.

I claim:

1. In a hydraulic cushioning device for application to one end of a railway car for cushioning buff and draft impacts delivered to the car coupler at such car end, and in which the cushioning device comprises a cylinder element and a piston element, one of which is adapted to be secured to the car underframe and the other of which is adapted to be operatively connected to the coupler, with the piston element being operably mounted in the cylinder element for reciprocating movement therein in operative relation with hydraulic liquid in said cylinder element for cushioning buff and draft impacts applied to the coupler, and with the cushioning device including means for controlling the flow of the hydraulic liquid through the piston element between a chamber on one side of the piston element and a chamber on the other side of the piston element, under impact forces acting on the coupler, for cushioning impacts applied to the coupler, by the passage of the hydraulic liquid between said chambers through said piston element to permit movement of the piston element under such impacts relative to the cylinder element, from a neutral position, including programmed metering pin means cooperating with a metering orifice in the piston element for providing said flow control on buff impacts in accordance with predetermined force travel relationships, and means for biasing said piston element to its neutral position, the improvement wherein said hydraulic liquid flow control means includes:

pressure responsive valve means for precluding hydraulic liquid flow between said chambers through the piston element under such impacts until fluid pressures in either of said chambers are at a predetermined pressure level relative to the other chamber, said valve means comprising a valve device carried by said piston element and cooperating with valve seat means to effect off-on control of hydraulic liquid flow through the piston element, said piston element being formed to expose said valve means to pressure conditions of the hydraulic liquid in both said chambers, said valve means being mounted in said piston element to be subject to and responsive to the pressures of the hydraulic liquid in the respective chambers, means for resiliently biasing said valve means against said seat means to effect blocking of hydraulic liquid flow through the piston element and being calibrated to permit said valve means to unseat from said seat means and permit hydraulic liquid flow between the chambers through the piston element under such impacts when said predetermined pressure level is reached in one of the chambers whereby hydraulic liquid flow through the piston element is accommodated to effect said cushion ing, said valve biasing means being effective to hold said valve means to fully block liquid fluid flow through said piston element until said predetermined pressure level is reached in the respective chambers independent of the position of the piston element longitudinally of the cylinder element, and valve seat means being in and carried by the piston element, and means independent of said orifice for confining return of hydraulic liquid between the chambers,

after cushioning of an impact by said movement of said piston element relative to said cylinder element, and said valve biasing means has closed said valve means, to between the cylinder element and the piston element and about the latter, and at a low volume flow snubbing rate, when the piston element biasing means is effective to return the piston element to its neutral position.

2. The cushioning device set forth in claim 1,

wherein: p i

the programmed metering pin means comprises a metering pin extending into said orifice and being fixed to said cylinder element at one end of said cylinder element,

with the portion of said metering pin extending between the side of the piston element facing said cylinder element one end, and said cylinder element one end, being free of encirclement by said valve member.

3. The cushioning device set forth in claim 1, wherein:

said hydraulic liquid return accommodating means comprises said piston and cylinder elements being formed to accommodate said hydraulic liquid return therebetween by way of tolerance variations.

4. The cushioning device set forth in claim 1, wherein:

said predetermined pressure level is in the range of from about 1,500 psi to about 2,500 psi.

5. In a hydraulic cushioning device for application to one end of a railway car for cushioning buff and draft impacts delivered to the car coupler at such car end, and in which the cushioning device comprises a cylinder element and a piston element, one of which is adapted to be secured to the car underframe and the other of which is adapted to be operatively connected to the coupler, with the piston element being operably mounted in the cylinder element for reciprocating movement therein in operative relation with hydraulic liquid in said cylinder element for cushioning buff and draft impacts applied to the coupler, and with the cushioning device including means for controlling the flow of the hydraulic liquid through the piston element between a chamber on one side of the piston element and a chamber on the other side of the piston element, under impact forces acting on the coupler, for cushioning buff and draft impacts applied to the coupler by the passage of the hydraulic liquid between said chambers through said piston element to permit movement of the piston element under such impacts relative to the cylinder element, from a neutral position, including programmed metering pin means cooperating with a metering orifice in the piston element for providing said flow control on buff impacts in accordance with predetermined force travel relationships, and means for biasing the piston element to its neutral position, the improvement wherein said hydraulic liquid flow control means includes:

pressure responsive valve means for precluding hydraulic liquid flow between said chambers through the piston element under such impacts until fluid pressures in either of said chambers are at a predetermined pressure level relative to the other chamber,

said valve means comprising a valve member carried by said piston element and mounted for movement relative to the piston element between a first position against a valve seat in which said hydraulic liquid flow through the piston element is blocked and a second position permitting said hydraulic liquid flow to accommodate said cushioning movement of the piston element,

said piston element being formed to expose said valve member to pressure conditions of the hydraulic liquid in both of said chambers,

said valve member being mounted in said piston element to be subject to and responsive to the pressures of the hydraulic liquid in said chambers,

means for resiliently biasing said valve member to said first position and being calibrated to permit movement of said valve member toward said second position when said predetermined pressure level is reached in one of said chamber,

said valve member biasing means being effective to hold said valve member to fully block said liquid fluid flow through said piston element in said first position of said valve member and until said predetermined pressure level is reached in one of the chambers independent of the position of the piston element longitudinally of the cylinder element,

said valve seat being in and carried by the piston element,

and means independent of said orifice for confining return of hydraulic liquid between the chambers, after cushioning of an impact by said movement of said piston element relative to said cylinder element, and said valve member biasing means has seated said valve member in said first position thereof, to between the cylinder element and the piston element and about the latter, and at a low volume flow snubbing rate, when the piston element biasing means is effective to return the piston element to its neutral position.

6. The cushioning device set forth in claim wherein:

wherein:

said programmed metering pin means comprises a metering pin extendingjnto said orifice,

said metering pin being fixed to said cylinder element at one end of the cylinder element,

with the portion of said metering pin extending between the side of the piston element facing said cylinder element one end, and said cylinder element one end being free of encirclement by said valve member.

8. The cushioning device set forth in claim 5 l0 wherein:

9. The cushioning unit set forth in claim 1, including:

safety relief valve means mounted in said piston element for limiting the pressure developed in one of said chambers to a predetermined maximum amount and including means for bypassing hydraulic fluid through said piston element when the last mentioned predetermined pressure has been reached,

said safety relief valve means comprising:

a passageway through said piston element and extending between said chambers,

a valve body mounted in said passageway and including a head closing said passageway and presenting a face exposed to said one chamber and formed to define a passageway extending longitudinally of said body from said face thereof,

said valve body defining a groove in the side wall of same and said body passageway communicating with said groove,

a sleeve slidably received over said valve body groove in sealing relation thereto and having an orifice formed therein adapted to communicate with said body passageway,

and spring means for biasing said sleeve relative to said valve body to maintain said sleeve orifice out of communication with said valve body groove,

said sleeve being formed with an annular shoulder thereabout exposed to said body groove for permitting said predetermined maximum pressure to move said sleeve against the action of said spring means to bring said sleeve orifice into communication with said groove whereby the hydraulic liquid may be' bypassed through said piston element passageway.

Claims

1. In a hydraulic cushioning device for application to one end of a railway car for cushioning buff and draft impacts delivered to the car coupler at such car end, and in which the cushioning device comprises a cylinder element and a piston element, one of which is adapted to be secured to the car underframe and the other of which is adapted to be operatively connected to the coupler, with the piston element being operably mounted in the cylinder element for reciprocating movement therein in operative relation with hydraulic liquid in said cylinder element for cushioning buff and draft impacts applied to the coupler, and with the cushioning device including means for controlling the flow of the hydraulic liquid through the piston element between a chamber on one side of the piston element and a chamber on the other side of the piston element, under impact forces acting on the coupler, for cushioning impacts applied to the coupler, by the passage of the hydraulic liquid between said chambers through said piston element to permit movement of the piston element under such impacts relative to the cylinder element, from a neutral position, including programmed metering pin means cooperating with a metering orifice in the piston element for providing said flOw control on buff impacts in accordance with predetermined force travel relationships, and means for biasing said piston element to its neutral position, the improvement wherein said hydraulic liquid flow control means includes: pressure responsive valve means for precluding hydraulic liquid flow between said chambers through the piston element under such impacts until fluid pressures in either of said chambers are at a predetermined pressure level relative to the other chamber, said valve means comprising a valve device carried by said piston element and cooperating with valve seat means to effect off-on control of hydraulic liquid flow through the piston element, said piston element being formed to expose said valve means to pressure conditions of the hydraulic liquid in both said chambers, said valve means being mounted in said piston element to be subject to and responsive to the pressures of the hydraulic liquid in the respective chambers, means for resiliently biasing said valve means against said seat means to effect blocking of hydraulic liquid flow through the piston element and being calibrated to permit said valve means to unseat from said seat means and permit hydraulic liquid flow between the chambers through the piston element under such impacts when said predetermined pressure level is reached in one of the chambers whereby hydraulic liquid flow through the piston element is accommodated to effect said cushioning, said valve biasing means being effective to hold said valve means to fully block liquid fluid flow through said piston element until said predetermined pressure level is reached in the respective chambers independent of the position of the piston element longitudinally of the cylinder element, and valve seat means being in and carried by the piston element, and means independent of said orifice for confining return of hydraulic liquid between the chambers, after cushioning of an impact by said movement of said piston element relative to said cylinder element, and said valve biasing means has closed said valve means, to between the cylinder element and the piston element and about the latter, and at a low volume flow snubbing rate, when the piston element biasing means is effective to return the piston element to its neutral position.

2. The cushioning device set forth in claim 1, wherein: the programmed metering pin means comprises a metering pin extending into said orifice and being fixed to said cylinder element at one end of said cylinder element, with the portion of said metering pin extending between the side of the piston element facing said cylinder element one end, and said cylinder element one end, being free of encirclement by said valve member.

3. The cushioning device set forth in claim 1, wherein: said hydraulic liquid return accommodating means comprises said piston and cylinder elements being formed to accommodate said hydraulic liquid return therebetween by way of tolerance variations.

4. The cushioning device set forth in claim 1, wherein: said predetermined pressure level is in the range of from about 1,500 psi to about 2,500 psi.

5. In a hydraulic cushioning device for application to one end of a railway car for cushioning buff and draft impacts delivered to the car coupler at such car end, and in which the cushioning device comprises a cylinder element and a piston element, one of which is adapted to be secured to the car underframe and the other of which is adapted to be operatively connected to the coupler, with the piston element being operably mounted in the cylinder element for reciprocating movement therein in operative relation with hydraulic liquid in said cylinder element for cushioning buff and draft impacts applied to the coupler, and with the cushioning device including means for controlling the flow of the hydraulic liquid through the piston element between a chamber on one side of the piston element and a chamber on the other side of the piston element, under impact forces acting on the coupler, for cushioning buff and draft impacts applied to the coupler by the passage of the hydraulic liquid between said chambers through said piston element to permit movement of the piston element under such impacts relative to the cylinder element, from a neutral position, including programmed metering pin means cooperating with a metering orifice in the piston element for providing said flow control on buff impacts in accordance with predetermined force travel relationships, and means for biasing the piston element to its neutral position, the improvement wherein said hydraulic liquid flow control means includes: pressure responsive valve means for precluding hydraulic liquid flow between said chambers through the piston element under such impacts until fluid pressures in either of said chambers are at a predetermined pressure level relative to the other chamber, said valve means comprising a valve member carried by said piston element and mounted for movement relative to the piston element between a first position against a valve seat in which said hydraulic liquid flow through the piston element is blocked and a second position permitting said hydraulic liquid flow to accommodate said cushioning movement of the piston element, said piston element being formed to expose said valve member to pressure conditions of the hydraulic liquid in both of said chambers, said valve member being mounted in said piston element to be subject to and responsive to the pressures of the hydraulic liquid in said chambers, means for resiliently biasing said valve member to said first position and being calibrated to permit movement of said valve member toward said second position when said predetermined pressure level is reached in one of said chamber, said valve member biasing means being effective to hold said valve member to fully block said liquid fluid flow through said piston element in said first position of said valve member and until said predetermined pressure level is reached in one of the chambers independent of the position of the piston element longitudinally of the cylinder element, said valve seat being in and carried by the piston element, and means independent of said orifice for confining return of hydraulic liquid between the chambers, after cushioning of an impact by said movement of said piston element relative to said cylinder element, and said valve member biasing means has seated said valve member in said first position thereof, to between the cylinder element and the piston element and about the latter, and at a low volume flow snubbing rate, when the piston element biasing means is effective to return the piston element to its neutral position.

6. The cushioning device set forth in claim 5 wherein: said valve member and said valve seat are in circumambient relation to said orifice.

7. The cushioning device set forth in claim 6 wherein: said programmed metering pin means comprises a metering pin extending into said orifice, said metering pin being fixed to said cylinder element at one end of the cylinder element, with the portion of said metering pin extending between the side of the piston element facing said cylinder element one end, and said cylinder element one end being free of encirclement by said valve member.

8. The cushioning device set forth in claim 5 wherein: said predetermined pressure level is in the range of from about 1,500 psi to about 2,500 psi.