US3186562A - Freight car underframe with hydraulic cushioning - Google Patents

Description

June 1, 1965 ANGOLD 3,186,562

FREIGHT CAR UNDERFRAME WITH HYDRAULIC CUSHIONING Filed Aug. 11, 1958 7 Sheets-Sheet 1 J. A. ANGOLD June 1, 1965 7 Sheets-Sheet 2 Filed Aug. 11, 1958 3 H V NW M m W J 2;}: :5: J H U \m M 1 1w: 1 1: d M L; 2 W W W .fl

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June 1, 1965 J. A. ANGOLD 3,136,562

FREIGHT CAR UNDERFRAME WITH HYDRAULIC CUSHIONING Filed Aug. 11. 1958 7 Sheets-Sheet v3 fizaenim J. A. ANGOLD 3,186,562

FREIGHT CAR UNDERFRAME WITH HYDRAULIC CUSHIONING June 1, 1965 7 Sheets-Sheet 4 Filed Aug. 11. 1958 s June 1', 1965 J. A. ANGOLD 3,186,562

FREIGHT CAR UNDERFRAIE WITH HYDRAULIC CUSHIONING Filed Aug. 11. 1958 7 Sheetfiheet 5 I 'l J I June 1,19 5 7 J. A. ANG OLD- 3,186,562

FREIGHT CAR UNDERFRAME WITH HYDRAULIC CUSHIONING I h I: Q va; Bay .4

- g I 'jnz/emfar' 5 .w v u 1 0? 0252503625.

United States Patent 3,186,562 FREEGHT CAR UNDERFRAME WITH HYDRAULIC (IUSHIQNING John A. Angold, Topeka, Kane, assignor to Keystone This invention relates to a railway car underframe construction wherein a hydraulic cushioning device is disposed to act between a floating sill and the fixed underframe for supplementing the cushioning action of the usual draft gears, which in this instance are disposed in the floating sill. More particularly, the invention is concerned with providing better protection to car lading, with particular emphasis being placed on the elimination of impact damage at the higher coupling speeds, which at the present time can sometimes result in serious damage to the car itself. Normal handling procedures prescribed by the A.A.R. define four mph. as the accepted coupling speed, but, on occasion, the actual coupling speed not infrequently may run as high as twelve to fifteen m.p.h., andsuch speeds have resulted in excessive lading damage.

While protection to lading is paramount, such protection must be achieved without imposing excessive strains on the car underfrarne construction. This problem of providing an economical car underframe construct-ion capable of properly cushioning high-speed coupling impacts for insuring safe handling of lading is a major one in modern railroad technology, and certainly one of the most expensive.

It will be appreciated that, while the car-coupling speeds during yard classification operations are of greatest significance, high impact loads are also applied to cars during normal train operation due to slack run in and slack run out, such as results when a long train moves into a steep-sided valley or over the hump of a hill.

Accordingly, the principal object of this invention is to reduce the impact shocks imparted to a freight car and the lading therein during classification and train operations. Briefly, this is accomplished with a cushioned underframe construction that includes a floating center sill having the usual draft gear devices at its opposite ends and connected to the fixed underfra-me structure through a hydraulic cushioning unit that is arranged in line within the floating sill to provide a long travel, energy absorption stroke for dissipating the high energy impact loads with a minimum of reaction to the car structure. The hydraulic cushioning unit is a double-acting device selectively reacting in opposite directions between the floating center sill and the fixed underframe structure.

Other objects and advantages will become apparent during thecourse of the following description.

In the accompanying drawings forming a part of this specification, and in which like numerals areemployed to designate like parts throughout the same:

FIG. 1 is a fragmentary perspective view of a car under-frame construction in accordance with this inven tion, with parts thereof broken away for clarity of illustration;

FIG. 2 is a detailed sectional view illustrating the construction and arrangement at one of the bolsters of the underframe, and is taken on the line 2-2 of FIG. 1; FIG. 3 is a detailed sectional view illustrating the construction and arrangement at a typical cross bearer of the underframe, and is taken along the line 33 of greases Patented June 1, 1965 FIG. 6 is a semi-diagrammatic elevational view through the cushioning unit, with parts thereof being shown in exploded relation, with the upper half of the figure being in section and the lower half being in elevation;

FIG. 7 is an elevational view through the assembled parts at one end of the hydraulic unit, with the upper half being shown in section; and

FIGS. 8A to 8B are graphs of the results of various performance characteristics of a car equipped with a cushioned underframe in accordance with this invention.

Referring now to the drawings and particularly to FIGS. 14 thereof, the car frame comprises a main underframe structure 26 providing a central guideway 21 extending lengthwise therethrough and a rigid, elongated column 22 disposed in the guideway and supported from the underfrarne structure for lengthwise sliding movement through the guideway. This slidable column 22 is hereinafter termed a floating sill, and, as is apparent from FIGS. 2 and 3, it has conventional double Z bars providing continuous top and side walls, and it is open along its bottom side to receive and house the various cushioning instrumentalities and cooperating stop abutments that are provided in accordance with the present invention.

In the illustrated form of this invention, these instrumentalities consist of a double-ended hydraulic cushioning unit 24 fixed to the opposed side walls of the floating sill centrally therealong, piston stop assemblies 25 fixed to the main underframe structure at positions adjacent opposite ends of the hydraulic cushioning unit 24, return spring assemblies 26 disposed in the floating sill at positions outwardly of the outer ends of the piston stop assemblies 25, and reacting between the floating sill and the main underframe structure to restore the floating sill, and hence the hydraulic unit, to their neutral centered position lengthwise in the main frame, and draft gear mechanisms 27 positioned in conventional draft pockets 23 provided in the floating sill and operatively connected with the usual yoke 2? and coupler 30. For convenience in illustration, one end portion of the main frame, including its associated return spring assembly 26 and draft gear mechanism 27, has been omitted; but it will be understood that both ends of the car frame are of identical construction.

, The general operation of this equipment will be apparent. The hydraulic unit 24 is a double-ended device and acts both in butt and in draft to cushion and absorb impact energy applied through the coupler 3d at either end of the car. Forces applied through the coupler are transmitted to the floating sill through the draft gear mechanism 27, and then are transmitted from the floating sill to the main frame through the fluid system of the hydraulic cushioning unit 24, with both the draft 'gear mechanism and the hydraulic cushioning unit initially acting simultaneously in cushioning and absorbing the energy of these forces. Closure travel of the draft gear mechanism is substantially completed well before that of the hydraulic unit, and the hydraulic unit absorbs the major share of the energy while maintaining reaction forces to the car frame at an acceptable level. This is accomplished by virtue of the long travel stroke (ten inches), which is permitted in the hydraulic unit as compared with the three or four inch maximum travel of the draft gear mechanism. The novel construction of the hydraulic unit for absorbing a maximum of energy under impact loading is described hereinafter.

The main underframe structure comprises lengthwise extending side sills 31; a pair of back-to-back, laterally spaced, lengthwise extending, channel-shaped Center sill members 32 that border and define the guideway 21; end sills 33; cross-bearer and crosstie members designated 34- and 35, respectively, connecting the side sills 31 to the center sill members 32; and bolster members 36.

The bolster framing details are shown in FIG. 2, which illustrates the manner in which the bolster members 36 mate flush with the edges of the channels 32 with a top tie plate 37 interconnecting the top sides of the bolster members and with a dished bolster center plate 38 having upwardly inclined lateral extensions 38E partially underlying and interconnecting the bottom sides of the bolster members. with lateral extending, depending ribs 38R (see FIG. 4) to strengthen the construction.

The framing details of the cross-bearers adjacent the hydraulic unit 24 are shown in FIG. 3, which illustratesthe manner in which the cross-bearer members 34 mate flush with the lateral edges of the channels 32, with a tie plate 4% being bridged across the floating sill and interconnect,-,

The bolster center plate is preferably, provided ing the top sides of the cross-bearer members, and with I pending reinforcement ribs 41R to strengthen the construction.

It will be apparent, th erefore, that the guideway 21gis bounded by continuous walls at its lateral extremities and by a number of longitudinally spaced tie members at its upper and lower sides. The various tie members sup-' The bottom porting and connecting the channels 32 of the main underframe for supporting the floating sill within the guideway are apparent in FIG. 4, and include the bolstercenter plate 38, the bottom plates diet the cross-bearers and cross" ties which support the piston stop assemblies 25, and numerous additional bottom tie members as indicated at 42.

The floating sill 22 is also provided with a number of bottom tie members, some of which. (as shown at 44) are disposed beneath and serve as carriers for the hydraulic unit; some of which (as shown at 45) are disposed beneath the piston stop assemblies and the remaining ones (as .shown at 46) are spaced along and give added rigidity to the floating sill. Ateach end of the floating sill, solid stops are provided in the form of bottom tie plates 47 arranged on opposite ends of the bolster center plate 38 and spaced therefrom for abutment with the bolster center plate in positively limiting travel of p the heating sill. In the preferred arrangement of this disclosure, these stops plates 47 are arranged to accommodate ten inches of travel.

The hydraulic unit 24 and the return spring assemblies stops for each of these assemblies, with the stops being a unique mounting relationshipv and mode of operation which facilitates its use in conjunction with a floating center sill structure and results in achieving a' significant elimination of lading damage at the higher coupling speeds; for example, 12 mph. T he hydraulic mechanism is arranged symmetrically within thefloating sill and functions therein as a double-ended in-line unit that supplies a maximum cushioning effect While requiring a minimum of mounting space. ts mounting location :within the floating sill simplifiesthe underframe structure. The inline action of the device minimizes the'establishment of damaging stresses, both in the underframe and in the floating sill, and is believed to contribute importantly in achieving the desired uniform response, of the hydraulic unit under shock loads. The hydraulic unit has the addi- I cushioning stroke, and this is done by'providing a hydraulic fluid friction system that'develops, a progressively increasing resistance ,to flow for maintaining the required pressures in the hydraulic system, even though the speed of closure progressively decreases throughout the length of thestroke; i V I As a further feature, the hydraulic unit is free of damaging recoil, with the return spring assembly 26 being depended upon for restoring thefloating sill and the hydraulic mechanism itself to its symmetrically neutral position centrally in the car. In this connection, the hydraulicmechanism develops a desirably low resistance during the restoring stroke.

The details of construction of the hydraulic mechanism are best shown in FIGS. 5 and 6. The mechanism includes the hollow, generally square shaped-outer casing 59 which, in addition 'to forming a convenient structure for attachment to the floating sill and for thereception arranged within the hollow floating sill and accommodating in-line mounting of the return spring assemblies, and particularly of the hydraulic unit;

7 Since the hydraulic unit is double acting, it has its outer casing-like main body 50 anchoredto the side walls 228 ing, bridge-like tie structure '52 that carries a separate face plate fixed at its innerend for abuting engagement with the ad acent piston rod. The tie structure has a generally channel-shaped, cross-sectional configuration, and is anchored fast to the bottom plates 41 of adjacent cross-bearer and crosstie' members.

Each return spring assembly 26. comprises a pair of vertically spaced, horizontally extending coil springs 64 reacting between a stop plate structure" 65 suitably fixed to the floating sill and a spring stop assembly 66 anchored to the bolster center plate 38. The spring stop assembly I 66 carries an abutment plate structure 668 providing seating engagement for the outer ends of the coil springs;

In the preferred form of the invention, as illustrated I herein for purposes of disclosure, the hydraulieunit 24 has and securement of the parts of the hydraulic mechanism, also provides a lubricant reservoir and recirculation chamber forlthe hydraulic fluid. The hollow housing'provides a generally square mounting chamberdl having an overall length of about 34 and a height and width of 11%,

with thechamber opening through circular-holes 52 at its opposite ends, these holesbeing bounded by corner flanges SilF provided on the housing for anchoring reservoir end castings 53 that cooperate witha double acting piston 54, an open ended cylinder 55, and cylinder head castings 56.

The various partsot' the hydraulic unit are best shown in FIG. 6, which-illustrates one end of the unit in exploded, aligned relation. It will'be understood that the unit is preferably.symmetrical, and that both ends are of identical construction. For convenience, the various parts of the unit are described individually, and thereafter their order ofassembly and mode of interaction are described. i

The end casting 53 has a generally square, cross-sectional shape to provide mating corner portions that are provided with countersunk holes SST-l ter attachment bolts 503 that are engaged in the-corner flanges, 50F of the housing. Each" end casting is formed Withan axial pistonrod passage753P having a diameter slightly greater than that ofrthe piston rod,.with a snitablebearing sleeve 57 provided therein adjacentto the "usual piston rod sealing facilities, which may includeV-shaped sealing elements 59V compacted betweena packing gland'plate59 and'a pressure ringofl under a pre-determinedaxial loadplate .59 carries awiplerfr'ing ing established: by coil springs'tiLejThepacking gland centric with the pistonfrod, V r 1 I a The end casting has an inwardly projecting frusto-con 59R that is maintained conisease cial shape, as indicated at 58, to provide a structural backing of desired length and strength for the bearing sleeve 5'7. Finally, the end casting is provided with a drilled bore 5313 for supplying hydraulic fluid to the system after the parts are assembled, with the bore opening through an otherwise continuous, annular locating shoulder 538 provided about the outer margin of an annular, intermediate face 53F provided on each end of the casting. The outside diameter of the shoulder 538 is approximately 11%. In addition, a groove 53G extends peripherally through the generally square shaped, inwardly directed face of the casting and receives a suitable gasket ring for sealing cooperation with the adjacent end of the reservoir housing St).

Each end casting cooperates with an adjacent cylinder head casting 56 having the general form of a circular ring to provide a central passage for the piston rod, and including an integral, outwardly projecting marginal annular wall 56W that terminates in end face 56F arranged for abutting engagement with the intermediate end face 53F of the adjacent end casting. This integral annular wall forms a central pocket 56F, which receives the tap ering, inner end portion 58 of the end casting with a suitable clearance being provided for a required hydraulic fluid return circuit, as will be described. A part of this circuit is provided by radially extending holes 56H that are drilled through the integral annular wall at spaced points about the periphery thereof to place the pocket in communication with the reservoir chamber.

The cylinder head is provided with a series of axial passages 56A in annular arrangement through its transverse faces, with these passages being blocked by a check valve mechanism 62 during the cushioning movement of the piston, and being exposed by release of the check valve mechanism during the return movement of the piston. The check valve mechanism comprises a sealing ring 62R resiliently pressed against the inner face of the cylinder head by a plurality of bolt and spring assemblies 62A, which normally maintain the sealing ring in masking sealing relationship across the inner ends of the passages, and which accommodate axial displacement of the sealing ring from the cylinder head to admit hydraulic fluid to the cylinder during the return stroke. Finally, the cylinder head has an annular recess 56R about the outer margin of the outer face formed by the annular wall 56W, with this recess being complemental to and receiving the locating shoulder 538 of the end casting to fixthese parts in aligned engagement.

The outside diameter of the cylinder head is approxirnately il /s" inches, and it therefore fits loosely within the reservoir chamber. Engagement of the shoulder 533 in the recess 56R centers the cylinder head with respect t? tlle end casting, and hence with respect to the reservoir 1 se The hydraulic cylinder 55 has an overall length of 26%", and is centered lengthwise within the reservoir housing 50, so that at each end the cylinder is set back from the end of the housing a sufficient distance to accommodate the cylinder heads and part of the end castings within the housing. The cylinder has an outer diameter of 11 /3", and, when positioned in engagement with the cylinder heads, is maintained centered within the reservoir chamber to provide a minimum clearance between the walls of the reservoir housing and the cylinder on the order of A5. To provide this centered engagement, the inner face of each cylinder head is formed with a marginal recess for receiving the adjacent end face 55F of the cylinder. It will be apparent, however, that the square shape of the housing leaves appreciable clearances at the corner regions of the reservoir chamber to provide this chamber with the desired fluid capacity. Maintaining The cylinder receives the symmetrical, double-ended piston and rod structure 5 preferably having the piston rods 54R formed integrally therewith and projecting coaxially from the opposite end faces of the double-ended piston 54F. It will be noted that this symmetrically arranged, double-ended piston structure maintains constant volume relationships within the hydraulic unit, since as the piston is displaced in one direction from'its centered neutral position the volume of the piston rod that is displaced at one end of the cylinder is exactly compensated by the other piston rod.

The hydraulic unit is preferably assembled on end. One reservoir end casting 53 is supported with its central passage overlying an open pit. A cylinder head casting is placed on the end casting in pre-determined aligned relationship, with these castings having mating dowel pin openings facilitating this alignment.

It will be apparent from a consideration of FIG. 7 that the two castings are brought together so that the annular shoulder 538 seats within the annular recess 56R of the head casting, with the flat, annular, opposing end faces 53F and 55F in abutting engagement. The reservoir housing is then applied over the assembled castings and supported with its end face resting on the gasket ring. The cylinder and piston may then be applied, it being noted that the end of the cylinder is received in the annular locating recess provided on the inner face of the cylinder head casting to maintain the cylinder in a centered, properly spaced position within the reservoir chamber of the housing. Finally, the other cylinder head and reservoir end are applied, and the bolts 50B are engaged between the reservoir housing and reservoir ends. When finally assembled, the cylinder is under axial compression by virtue of direct metal-to-metal contact between the ends of the cylinder and the cylinder heads, and between the cylinder heads and the reservoir end castings. The clearances are selected so that the gasket ring is under a predetermined compression between the ends of the housing and the reservoir end castings, but these parts are not in direct metal-to-metal contact.

After assembly of the parts is completed and with the unit in a horizontal position, as indicated in FIGS. 6 and 7, hydraulic fluid is introduced through the passage 53B in the end castings, and it flows around the cylinder head and the cylinder to the reservoir chamber, and also flows through a radial passage 56K in the cylinder head to the head casting pocket 56F to ultimately fill the cylinder itself. The reservoir is filled to the level L (see FiG. 7) to proyide suflicient air space for expansion of the hydraulic fluid. The mechanism is then inserted upwardly into the floating sill and secured therein, with the tie plates 44 being removable for accommodating insertion and removal of the hydraulic unit.

As mentioned previously, when the hydraulic mechanism is in place within the floating sill its functions in conjunction with the draft gear mechanisms in cushioning impact loads applied through the couplers; and, being double acting, it responds both in buff and in draft in handling loads applied from either end of the car. In the hydraulic mechanism, the impact loads applied from the floating sill to the reservoir housing act to displace the housing from its centered, neutral position lengthwise of the under frame, while the piston rods 54R abut against the piston stop assemblies and maintain the piston stationary with respect to the underframe.

As will be apparent, the cylinder heads and reservoir ends move as a unit with the housing, and the relative movement of these parts with respect to the piston is cushioned, while the energy of impact is dissipated by hydraulic fluid friction developed under the influence of hydraulic fluid pressures that are established and maintained in the cylinder. In accordance with the invention, these pressures are maintained at a high and generally uniform level throughout the'cushioning stroke.v This is best done by arranging the friction-producing fluid passages so that their effective area progressively decreases throughout the I passage area is constant throughout the length of the stroke. A piston operating in a straight bore with a PI'EGB-C termined constant peripheral clearance is typical.

The preferred fluid passage arrangement may be'cmbodied in a number of ways; for example, the cylinder through which the piston moves may be made slightly larger than the piston to provide flow passages in the form of peripheral clearances; In this case, the bore of the cylinderv is tapered from a maximum at the center to a minimum at each end. Alternatively, the cylinder may have a straight bore of uniform, circular cross-section with the flow passages being formed by providing grooves" lengthwise in the cylinder walls, with the size of the grooves being a maximum adjacent the center of the cylinder, and a minimum at the opposite ends. In the preferred construction disclosed herein for purposes of illustration, the cylinder 55 has a'straight bore of uniform, circular cross-section cooperating with a piston having its cylindrical sealing wall formed with a pair of axially spaced grooves 54G to receive a pair of piston ringsin continuous sealing engagement with the cylinder wall. In this disclosure, the cylinder wall is provided with an arrangement of axially spaced orifice. openings 55-0 (see FIGS. and 6). communicating between the reservoir chamber and the cylinder. These orifice openings are preferably located to feed directly into the corner regions of the reservoir chamber, and this minimizes fluid frictional resistance in'the return circuitthat is established for the hydraulic fluid during the operating stroke 'of the unit. This return circ'uit is completed through a set of enlarged holes 55H provided approximately centrally along the length of the cylinder at spaced points about the periphery thereof.- These enlarged holes'are masked by the piston when it is in its centered, neutral position, and are progressively ex-.

be' cor-related with: the return spring assemblies to provide for a rapid andcasyreturn of the piston.

The performance characteristics of a cushioned underframe, in accordance with this invention, are illustrated in the graphs of FIGS. 8A to 8B. Reference should I first be had, however, to the curve ofpFlG. 8D, the

' that were niadeover a, range of impact speeds.

tests, a moving car Was coupled with a capacity-loaded ordinate of which indicates the effective orifice area at car standing at rest and backed up byisix empty cars which had their air'brakes set. Only the moving car had the cushioned underframe of this invention. actual tests, the cushioned underframe was provided with arubber draft gear, while the adjacent endfof the standing car was provided with'a friction draft gear, and these, two draft 7 gear mechanisms functioned with the hydraulic mechanism in cushioning and dissipating the energy of impact.

Under these conditions, therefore, the curve of FIG.

' 8A illustrates that-the travel or displacement of the posed as the piston is displacedtoward one end of the a a cylinder.

It will be immediately apparent that, as the piston is moved toward the end of the cylinder and fluid isfor'ced from the cylinder chamber and through the orifice openings, the pressure within the cylinder is dependent'upon the. size of these orifices and upon the speed of travel of the vpistonerelative to the cylinder., The piston speed reaches a maximum shortly after impact, and is there after reduced as the piston is brought to rest, preferably immediately before the positivestops can engage. While the piston speed decreases, fluid pressures are maintained generally uniform by arranging the'orifices to provide a correspondingly decreasing effective orifice area. It will be apparent that, as'the piston is displaced toward the end of the cylinder, it progressively masks and bypasses more 'duced, and this arrangement avoids adangerous stress-- 'ing of the housing 50. I a

When the impact loading is removed, the returnspring assemblies 26 react between the main frame and the floating sill-to restorethe parts to their centered neutral 7 position; and, 'as the piston'returns through-the cylinder,

hydraulic, fluid flows principally through the enlarged holes 551-1, through the reservoir chamber, and then.

through the' radial holes 56H in the cylinder. head to force open the check valve ring 62R and refill the previously evacuated chamber. It will be apparent that this piston from its centered neutral position is approximately 9 /2" at a 12 mph. 'coupling' speed, and is reduced only. to about 6 for al mph. coupling speed; It is significant that, even at'speedsof 12 mph, the 10" allowable :t'ravelis not fully used up. While solid stops come into play'after 10 of travel, it is important'that this be avoided wherever possible in order to eliminate undesirable shocks that may damage not'only the lading but the underframe structure itself.

It is also interesting that for the lowerspeeds the hydraulic mechanism develops a relatively long cushioning stroke, and this,'of course, permits it to handle im pacts at these speedsquite effectively.

The curve of FIG. 8B is believed to be sel -explanatory in that it shows the approximateacceleration or deceleration which the carundergoes for the range of coupling speeds. Similarly, curve 8C is self-explanatory, and it illustrates the coupling force developed at various impact speeds; This is the force that is applied throughthe coupler and transmitted through the floating sill and the hydraulic mechanism to the piston stop, assembly,

. which then distributes it to the underframe. Even for amplifier that feeds into a recording oscillograph. It 7 should be understoodrthat there .is no output from the accelerometer immediately prior to impact. or when the parts are finally brought to a rest condition; The velocity curve rises rathersharplyat impact, and then drops off: to extend below thebase'line until the rest condition is attained. Considering" that thefhorizontal base line defines a constant rate of change ofvelocity from impact speed to the rest condition, theisvelocity :curve of FIG. SEindicates that. the acceleration or deceleration is' somewhat greater than average during the .fluid circuit provides a low-resistant fiow pathydepende ing on the adjustment of the check valve; and this may.

initial closure,-and. it is thereafter. somewhat lesser than average, v 4 Y i I Thus, .it may be 'seen'thattheobjects of this inven- 'tion have beenaccomplished in that the ,hydraulic mechanism, when embodied more floating sill of acushioned undcrframe, rnarkedlyreducescoupling forces applied to the car, and hen'ce better protects the .lading;

f The in-line'lmounting of the hydraulic ni cchanism In the simplifies the fabrication of the underframe structure and facilitates assembly of the unit within the underframe while also minimizing dangerous stress conditions in the underframe, and particularly in the floating sill. Important advantages also exist from the standpoint of maintenance, particularly in connection with the provision of the reservoir, which tests indicate has never been subjected to a pressure greater than 70 pounds per square inch. Similarly, the pressures at the piston rod sealing arrangement are held within this range, and this greatly minimizes maintenance problems.

It should be understood that the description of the preferred form of the invention is for the purpose of complying with Section 112, Title 35, of the US. Code, and that the claims should be construed as broadly as the prior art will permit.

I claim:

1. In combination, an underframe structure having a guideway extending lengthwise therethrough, a channel shaped unitary floating sill structure in the guideway to project from opposite ends thereof and slidably supported from the underfrarne structure, a hydraulic cushioning unit disposed in the floating sill structure and including a double-ended hydraulic cylinder lengthwise in the guideway and fixed to the floating sill structure and a double-ended piston and piston rod assembly slidable lengthwise in the cylinder to develop hydraulic fluid pressure therein, with the piston rods projecting from opposite ends of the cylinder to abut with cooperating stops fixed to the underfrarne structure and projecting within the floating sill structure adjacent opposite ends of the assembly, said unit having means providing a hydraulic fluid flow path between opposite ends of the cylinder for developing fluid frictional resistance to relative lengthwise movement between the cylinder and the assembly so that the unit resists relative lengthwise movement between the structures by developing hydraulic fluid friction under hydraulic pressure, and a separate return spring assembly disposed within the floating sill structure in lengthwise outwardly spaced relation from each end of the hydraulic cushioning unit and each including resilient lengthwise extending spring means reacting between an inner stop abutment fixed to the floating sill structure in alignment with the hydraulic unit and an outer stop abutment fixed to a bolster center plate of the underframe structure and projecting upwardly into the floating sill structure and aligned with the hydraulic unit.

2. In combination, an underframe structure having a guideway extending lengthwise therethrough, a channel shaped unitary floating sill structure in the guideway to project beyond opposite ends thereof and slidably supported from the underframe structure, a hydraulic cushioning unit disposed in the floating sill structure and ineluding a double-ended hydraulic cylinder lengthwise in the guideway and fixed to the floating sill structure and a double-ended piston and piston rod assembly slidable lengthwise in the cylinder to develop hydraulic fluid pressure therein, with the piston rods projecting from opposite ends of the cylinder to abut with cooperating stops fixed to the underframe structure and projecting within the floating sill structure adjacent opposite ends of the assembly, said unit having means providing a hydraulic fluid flow path between opposite ends of the cylinder for developing fluid frictional resistance to relative lengthwise movement between the cylinder and the assembly so that the unit resists relative lengthwise movement between the structures by developing hydraulic fluid friction under,

unit and being aligned horizontally for positive engagement.

3. The arrangement of claim 2, wherein a bolster center plate of the underframe structure functions as one of said stops.

4. In combination, an underframe tructure comprising opposed horizontally extending channel members defining a lengthwise extending guideway that is open at the bottom, side sills extending parallel to and flanking the channel members, end sills connecting the ends of the side sills and channel members, and a plurality of cross-bearer and crosstie members connecting the side sills to the channel members at spaced points therealong, a channel shaped unitary floating sill structure disposed lengthwise in the guideway, with the underframe structure including bottom tie members bridging the guideway and slidably supporting the floating sill structure therein, piston stop assemblies disposed in alignment within the floating sill and spaced apart lengthwise on opposite sides of the transverse center line of the underframe structure, said assemblies each comprising a bridging member extending lengthwise between and fixed to bottom plates of adjacent cross-bearer and crosstie members to provide cooperating lengthwise spaced horizontally aligned stops, and a hydraulic cushioning unit disposed in the floating sill structure and including a double-ended hydraulic cylinder lengthwise in the guideway and fixed to the floating sill structure and a double-ended piston and piston rod assembly slidable lengthwise in the cylinder to develop hydraulic fluid pressure therein, with the piston rods projecting from opposite ends of the cylinder to abut with the piston stop assemblies, said unit having means providing a hydraulic fluid flow path between opposite ends of the cylinder for developing fluid frictional resistance to relative lengthwise movement between the cylinder and the piston assembly so that the unit resists relative lengthwise movement between the structures by develop ing hydraulic fluid friction under hydraulic pressure.

5. In combination, an underframe structure having a guideway extending lengthwise therethrough, a channel shaped floating sill structure in the gui eway and slidably supported from the underframe structure, and a hydraulic cushioning unit disposed in the floating sill structure and comprising a double-ended hydraulic cylinder lengthwise of the guideway, an outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly extending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder to abut with cooperating stops fixed to the underfrarne structure and projecting within -the floating sill structure adjacent opposite ends of the assembly, and cylinder heads Within the casing in telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, said unit providing a hydraulic fluid flow path for developing fluid frictional resistance to relative lengthwise movement between the cylinder and the assembly such that the unit resists relative lengthwise movement between the structures, each head having fluid flow passage means extending therethrough to connect between the cylinder and reservoir chamber and said cylinder having fluid return holes centrally therealong opening into the reservoir chamber to compl-etea hydraulic fluid return circuit, with the fluid return holes being masked by the piston when the piston is in a neutral centered position within the cylinder, with each head having check valve means normally blocking flow outwardly through the head as thepiston is moved toward such head, thereby developing hydraulic fluid pressure Within the cylinder, said check valve means being yieldable to accommodate flow inwardly through the head.

6. The arrangement of claim 5, wherein the hydraulic fluid flow path for developing fluid frictional resistance to relative lengthwise movement between the cylinder and the assembly is provided in-the form of holes opening through the periphery of the cylinder, said holes being distributed along the length of the cylinder such that the eflective orifice area thereof progressively decreases during the cushioning stroke of the hydraulic unit.'

7. The arrangement of claim 5, wherein the hydraulic unit includes separate reservoir end castings in telescoping relation over the piston rods and in direct abutment with the adjacent cylinder head, and means for securing the, end castings to the casing with the end castings-holding the cylinder heads in compression against the cylinder, with each end casting having peripheral sealing means in sealing engagement with the adjacent end of the casing,

and with each end casting being formed with a plugged filling bore communicating with the reservoir chamber and with the outer end of the adjacent cylinder head.

8. In combination, anunderframe structure comprising opposed horizontally extending channel members defining a lengthwise extending guideway that is open at the bottom, side sills extending parallel to and'flanking the channel members, end sills connecting the ends of the side sills and channel members, and a plurality of crossbearer and crosstie members connecting the side sills to the channel members at spaced points therealonga channel shaped floating sill structure disposed in the guideway, with the underframe structure including bottom tie members bridging the guideway and slidably supporting the floating sill structure therein, piston stop assemblies disposed within the floating sill and spaced apart length- 'WlSE/ on opposite sides of the center line of the underframe structure, said assemblies each comprising abridging member extending lengthwise-between and fixed to bottom plates of adjacent cross-bearer and crosstie members to provide cooperating lengthwise spaced horizontally aligned stops, and a hydraulic cushioning unit disposed 'in, the floating sill structure and comprising a doubleended hydraulic cylinder lenghwise of the guideway, an.

outer casing housing the cylinder and'forming areservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly ext-ending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder to abut with the piston stop assemblies, and cylinder heads within the casing in telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, said unit providing a hydraulic fluid flow path for developing fluid frictional resistance to relative lengthwise moveended hydraulic cylinder lengthwiseof the guideway, an

outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly extending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder to abut with the piston stop assemblies, and cylinder heads within the casing in telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, said unit providing a hydraulic fluid flow path for'developing fluid frictional resistance to relative lengthwise movement between the cylinder and the assembly such that the unit resists relative lengthwise movement between the structures, each head having fluid flow passage means extending therethrough to connect between the cylinder and reservoir chamber and said cylinder having fluid return 7 holes centrally therealong opening into the reservoir chamber to complete a hydraulic fluid return circuit, With the fluid return holes being masked by the piston when the piston 'is in 'a neutral centered position within the cylinder,-with each headhaving check valve means normally blocking flow outwardly through the head as the ment between the cylinder and the assembly such that i the unit resists'relative lengthwise movement between the structures, each head having fluid flow passage means" extending therethrough to connect between the cylinder and reservoir chamber and said cylinder having fluid re-' turn holes centrally. therealong opening into the reservoir chamber to complete a hydraulic fluid return circuit, with the fluid return holes beingmasked by the piston when the piston is in a neutral centered position within the cylinder, with each head having check valve means normally blocking flow outwardly through the head as the piston is moved toward such head, thereby developing hydraulic fluid pressure within the cylinder, said check valve means being yieldable to accommodate flow in-t wardly through the head. 7 i

9. In combination, an underframe structure comprising opposed horizontally extending channel members dew fining a lengthwise extendin guideway that is open at the bottom, side sills extendingparallelto and flanking the channel members, end sillsconnecting the ends of the side sills andchannel members, and a plurality of cross bearer and crosstie members connecting the side sills to the channel members at spacedpo ntstherealong, a channel shaped floating sill structure disposed in the guideway,

with the underframe structure including bottom tie mem- 'bers bridging the guideway and slidably supporting the floating sill structure therein, said floating sill structure piston is moved-toward such head, thereby'developing hydraulic fluid pressure within the cylinder, said' check valvemeans being'yieldable to accommodate flow in-' wardly through-the head. i

1%. In combination, an underframe structure having a guideway open, at the bottomaand extending lengthwise through the underframe structure, a channel-shaped floating sill structure having anro'pen bottom andlsupported from the underframe structure for lengthwise sliding movementin the guideway, said floating sill structure extending the length of said guideway and having aligned draft pockets adjacent opposite ends thereof, adratt gear mechanismoperatively mounted in each pocket, coupling mechanism to each draft gear mechanism for transmitt-ing butt and draft impact forces therethrough to thefloating sill structure, and a double-acting hydraulic cushioning unittdisposed in the floating sill structure intermediately betweenand aligned with the draft pockets and including a double-ended hydraulic cylinder lengthwise of the guideway and fixed'to the floating sillstructure anda doubleended piston and 'pistonrod assembly slidable in the cylinder to develop hydraulic fluid pressuretherein, with t the piston 'rods' projecting from opposite ends of the cylinder to abut with cooperating stopsflxed tothe underframe structure and projecting 'withinfthe' floating sill structure adjacent opposite ends'of the assembly, said hydraulic unit includingan outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, and cylinder heads within the casing in having aligned draft pockets adjacent opposite ends there of, a draft gear mechanism ioper'atively mounted in each position within thecylinder;

telescoping relation over the piston rods to seal'the cylinder at opposite ends: thereof, each head having fluid flow passage-means extending therethrOughtoconnect between the cylinder and "reservoir chamber, with each head having check valve means normally blocking flow outwardly through the headand yieldable to accommodate flow inwardlylthrough the head; and said cylinder having fluid-return holes centrallytherealong'opening 7 into the reservoir chamber to complete a hydraulic fluid return 'circ'uitpwith the -'fluid-ret,urn, holes being masked, neutral centered by the pistonwhenthe piston is in a- 11 The arrangement of claim 1d wherein the hydraulic unit includes separate reservoir end castings in sealing, telescoping relation over the piston rods and in direct, sealing abutment with the ends of the casing and means for securing the end castings to the casing with the end castings holding the cylinder heads against the cylinder to provide a low-pressure space between each end casting and the cylinder head adjacent thereto, each said space serving as a fluid flow passage between the cylinder and the reservoir chamber.

12. In combination, an underframe structure having a guideway extending lengthwise therethrough, a channelshaped floating sill structure in the. guideway and slidably supported from the underfrarne structure, and a hydraulic cushioning unit disposed in the floating sill structure and comprising a double-ended hydraulic cylinder lengthwise of the guideway, an outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly extending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder to abut with cooperating stops fixed to the underframe structure and projecting within the floating sill structure adjacent opposite ends of the assembly, and cylinder heads within the casing in telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, said unit providing a hydraulic fluid flow path for developing fluid frictional resistance to relative lengthwise movement between the cylinder and the assembly such that the unit resists relative lengthwise movement between the structures, each head having fluid flow passage means extending therethrough to connect between the cylinder and reservoir chamber, with each head having check valve means normally blocking the flow outwardly through the head as the piston is moved toward such head, thereby developing hydraulic fluid pressure within the cylinder, said check valve means being yieldable to accommodate flow inwardly through the head.

13. In combination, an underframe structure comprising opposed horizontally extending channel members defining a lengthwise extending guideway that is open at the bottom, side sills extending parallelto andflanking the channel members, end sills connecting the ends of the side sills and channel members, and a plurality of crossbearer and crosstie members connecting the side sills to the channel members at spaced points therealong, a channel-shaped floating sill structure disposed in the guideway, with the underframe structure including bottom tie members bridging the guideway and slidably supporting the floating sill structure therein, piston stop assembliesidisposed within the floating sill and spaced apart lengthwise on opposite sides of the center line of the underframe structure, said assemblies each comprising a bridging member extending lengthwise between and fixed to bottom plates of adjacent cross-bearer and crosstie members to provide cooperating lengthwise spaced horizontally aligned stops, and a hydraulic cushioning unit disposed in the floating sill structure and comprising a double-ended hydraulic cylinder lengthwise of the guideway, an outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly extending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder to abut with the piston stop assemblies, and cylinder heads within the casing in telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, said unit providing a hydraulic fluid flow path for developing fluid frictional resistance to relative lengthwise movement between the cylinder and the assembly such that the unit resists relative lengthwise movement between the structures, each head having fluid flow passage means'extending" therethrough to connect between the cylinder and reservoir chamber, with each head having check valve means normally blocking flow'outwardly through the head as the piston is moved toward such head, thereby developing 1d hydraulic fluid pressure within the cylinder, said check valve means being yieldable to accommodate flow inwardly through the head.

14. A hydraulic cushioning unit comprising a doubleended hydraulic cylinder, an outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly extending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder, and cylinder heads within the casing in telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, said unit providing a hydraulic fluid flow path for developing fluid frictional resistance to relative lengthwise movement between the cylinder and the assembly, each head having fluid flow passage means extending therethrough to connect between the cylinder and reservoir chamber, with each head having check valve means normally blocking flow outwardly therethrough as the piston is moved toward such head, thereby developing hydraulic fluid'pressure within the cylinder, said check valve means being yieldable to accommodate flow from the reservoir chamber inwardly through the head. I

15. In combination, an underframe structure having a guideway extending lengthwise therethrough, a channelshaped floating sill structure in the guideway and slidably supported from the underframe structure, and a hydraulic cushioning unit disposed in the floating sill structure and comprising a double-ended hydraulic cylinder lengthwise of the guideway, an outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly extending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder to abut with cooperating stops fixed to the underframe structure and projecting within the floating sill structure adjacent opposite ends of the assembly, and cylinder heads within the casing in telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, said cylinder having holes spaced along the length thereof forming a reversible hydraulic fluid flow path between opposite ends of the cylinder, said flow path including the reservoir chamber.

16. In combination, an underframe structure having a guideway extending lengthwise therethrough, a channelshaped floating sill structure in the guideway and slidably supported from the underframe structure, and a hydraulic cushioning unit disposed in the floating sill structure and comprising a double-ended hydraulic cylinder lengthwise of the guideway, an outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly extending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder to abut with cooperating stops fixed to the underframe structure and projecting within the floating sill structure adjacent opposite ends of the assembly, and cylinder heads within the casing in telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, said unit having means providing a reversible hydraulic fluid flow path between opposite ends of the cylinder for developing uniform fluid frictional resistance characteristics to relative lengthwise movement in either direction between the cylinder and the piston assembly.

17, In combination, an underframe tructure having a guideway extending lengthwise therethrough, a channelshaped floating sill structure in the guideway and slidably supported from the underframe structure, and a hydraulic cushioning unit disposed in the. floating sill structure and comprising a double ended hydraulic cylinder lengthwise of the guideway, an outer casing housing the cylinder and forming a reservoir chamber therearound for hydraulic fluid, a double-ended piston and piston rod assembly extending lengthwise through the cylinder with the piston rods thereof projecting from opposite ends of the cylinder V to abut with cooperating stops fixed to the underframe structure and projectingwithin the floating sill structure adjacent opposite ends of the assembly, and cylinder heads within the casing in-telescoping relation over the piston rods and sealing with the cylinder at opposite ends thereof, 1

separate reservoir end castings in telescoping relation over the piston rods andin direct abutment with the adjacent cylinder head, means for securing the end castings to the casing; with the end castings holding the cylinder heads in compression against the cylinder, with each end casting having peripheral sealing engagementwith the adjacent end of the casing, and means providing a reversible hydraulic fluid-flow path between oppositerends of the cylinder for developing uniform fluid frictional resistance characteristics to relative lengthwise movement in either; direction between the cylinder and the piston,

assembly.

18. In combination, an underfname structure having a guideway extending lengthwise therethrough, a rigid elongated unitary column structure in the guideway to ported from said underframe structure, a hydraulic cushioning mechanism disposed within said guideway intermediately therealong and including a hydraulic cylinder lengthwise in the guideway and a piston and piston rod assembly slidable in the cylinder to develop hydraulic fluid pressure therein, said mechanism having flow restricting means providing a hydraulic fluid flow path between oppositesides of the piston for developing fiuid'frictional resistance to relative lengthwise movement between the cylinder and the assembly, and abutment means on one of said structures engaging said cylinder at 1 one end of said mechanism and abutment means on the other of said structures engaging said assembly at the opposite end of said mechanism so that the mechanism resists relative lengthwise-movement in either direction 7 between the structures by developing hydraulic fluid friction under hydraulic pressure.

'19. The combination of claim 18 further characterized by the provision of spring means for returning said cushioning mechanism'to its initial position following an 20 project beyond opposite endsgthereof and slidably, sup-' in, V structure to the vehicle body, an auxiliary sill extending longitudinally within said center sill structure and adapted to movevlongitudinally with respect thereto and having a neutral position,;a coupler and 1a draft' rigging arranged within said 'auxiliary' sill structure adjacent said first end of said body, a coupler and a draft rigging arranged within said auxiliary sill structure adjacent said second end of said body, means connecting each, driaft rigging to said auxiliary sill structure whereby it is moved relative to said center sill structureupon application of an impact to either coupler, a cylinder mounted Withinsaid auxiliary sill structure, means, securingithe cylin der to the center sill structure, a piston movable within said cylinder and arranged in a central position therein inrthe neutral posia railway vehicle body, a center sill structure extending longitudinally of said bodyand secured thereto, an auxiliary sill structure extending longitudinally withinjsaid center sill structure and arranged'for lengthwise movements with'respect to the center s'ill structure, resilient means maintaining said auxiliary sill structure in a new tral position with respect to the center sill structure, a coupler and a draft riggingiarranged within the auxiliary structure, means connecting said draft rigging to said auxiliary-sill structure, a cylinder mounted within said sill structures, means including transversely spaced block impact force against either end of said column structure. 1

26'. In a railway car: a longitudinally extending hollow center'sill fixed to the car; asliding center, sill member longitudinally slidably mounted in said fixed center sill; cooperating stop means carried by said fixed center si l and said sliding member limiting longitudinal movement of said member; resilient means biasing said member to a neutral position; a double-acting, hydraulic, piston-and cylinder buffer mechanism having a first external coupling element connected to the piston and a second external elements secured to said. centersill structure engaging the respective ends of the cylinder. maintaining it in a fixed position withrespectto the center: sill structure, a piston mounted for movement within'ithe cylinder, a rod carried 'by said piston extending towards the coupler through the associated end of the cylinden liquid within said cylinder,

' an abutment member carried by the: auxiliary sill structure spaced from one end of the cylinder in the neutral position of the auxiliary sill structure, means carried by said abutment member engaging said piston: rod in the neutral position of the'auxiliary sill structure, and said cylinder having a metering opening throughwhich said liquid is forced by movement of the piston.

coupling element connected to the cylinder; means connecting one of said coupling elements to said slidingmember;.and means connecting the other of said coupling elements to said car.-

21. In a railway car: a longitudinally extending hollow center-sill fixed to the car; a sliding center sill mounted longitudinallyslidably mounted in said fixed center sill and extending substantially the entirelength of saidfixed center sill;'cooperating stop means carried by said fixed center sill and said sliding member limiting longitudinal movement of said member;resilient meansbiasing said member to a neutral position midway between. the limits ofmovement of said member; a dou'bleracting, hydraulic,

piston-and-cylinder buffer mechanism having a first ex ternal coupling element connected to the piston and a second external coupling element connected to the cylin. der; means connecting one of said coupling elements to said sliding member; andrmeans connecting the other of said coupling elements to said fixed center sill.

22. A cushion mechanism for a railway vehicle fQr ab fsorbing theenergy of an impact applied to, a coupler thereof comprising, a railway vehicle body, a center sill structure; extending longitudinally of said body from a first end to a second end, means fixing the center sill 24. A'mechanism for absorbing the energy of an impact appliedto a coupler of arrailway vehicle comprising, a railway vehicle body, a center'sill structure extending longitudinally of said body andisecured thereto, an

auxiliary sill vstructure extending longitudinally within' saidcenter sill' structure and arranged for lengthwise movements with respect to thecenter sill structure, resilient means maintaining said auxiliary-sillstructure in a neutral position with respect to the" center sillistructure, a coupler and a draft rigging arranged within each end of; the auxiliary sill structure, means connecting each draft rigging to said auxiliary sill structure, a cylinder,

mounted within the mid-portion of said centersill' structure, transversely'spaced block elements secured a; said center ,sill structure engaging the respective ends of the cylinder maintaining it in a-fixed position with respect to the center sill structure, a piston mountedfor movements withinthe cylinder and having a rmid position-thereinin the neutral position ofthe auxiliary sill'structure,-fa piston rod carried ,by'the'piston extending-fromeach end ofthe cylinder, liquid substantially filling, said cylinder, abutment-members 'carr'iedi by :the auxiliary sill structure spaced from the associated block elements in the neutral position of the auxiliary 'sill structure, a prOjectionczirried 'l)y:each abutment member engaging an end of said piston rod, and said cylinder "having a plurality of metering grooves in the wall thereof through which said liquid is forced upon relative movements of the piston with respect to the cylinder.

25. A cushion mechanism for a railway vehicle for absorbing the energy of an impact applied to a coupler thereof comprising, a vehicle body, a center sill structure extending longitudinally of said body and secured thereto, an auxiliary sill structure extending lengthwise within said center sill structure arranged for movements longitudinally relative to said center sill structure, a coupler and a draft rigging carried by an end portion of said auxiliary sill structure, means coupling said draft rigging to said auxiliary sill structure for moving the auxiliary sill structure relative to said center sill structure upon application of an impact to said coupler, a cylinder mounted within said auxiliary sill structure, a piston within said cylinder, a piston rod extending through opposite ends of said cylinder, liquid within said cylinder, means carried by the auxiliary sill structure in abutting relationship with one end of said piston rod, means carried by the auxiliary sill structure in abutting relationship with the other end of said piston rod, members carried by the center sill structure engaging opposite ends of said cylinder preventing longitudinal movements of the cylinder relative to the center sill structure, and means for controlling the flow of liquid from one side of said piston to the other side thereof to cushion movements of the auxiliary sill structure relative to the center sill structure.

26. A cushion mechanism for a railway vehicle for absorbing the energy of an impact applied to a coupler thereof comprising, a vehicle body, a center sill structure extending longitudinally of said body and secured thereto, an auxiliary sill structure extending lengthwise within said center sill structure arranged for movements longitudinally relative to said center sill structure, a coupler and a draft rigging carried by an end portion of said auxiliary sill structure, means coupling said draft rigging to said auxiliary sill structure for moving the auxiliary sill structure relative to said center sill structure upon application of an impact to said coupler, a cylinder mounted within said auxiliary sill structure, a piston within said cylinder, a piston rod extending through opposite ends of said cylinder, liquid within said cylinder, members carried by one of said sill structures in abutting relationship with the opposite ends of said cylinder, members carried by the other of said sill structures in abutting relationship with opposite ends of said piston rod to produce relative movement between the piston and the cylinder during relative movement of the auxiliary sill structure and the center sill structure, and means metering movement of said liquid during relative movement of the piston and the cylinder.

27. A cushion mechanism for a railway vehicle for absorbing the energy of an impact applied to a coupler thereof comprising, a vehicle body, a center sill structure extending longitudinally of said body and secured thereto, an auxiliary sill structure extending lengthwise within said center sill structure arranged for movements longi- 18 tudinally relative to said center sill structure, a coupler and a draft rigging carried by an end portion of said auxiliary sill structure, means coupling said draft rigging to said auxilary sill structure for moving the auxiliary sill structure relative to said center sill structure upon application of an impact to said coupler, a cylinder mounted within said auxiliary sill structure, a piston within said cylinder, a piston rod extending through opposite ends of said cylinder, liquid within said cylinder, means securing said cylinder against axial movements with respect to said center sill structure, members carried by the auxiliary sill structure in abutting relationship with opposite ends of said piston rod to produce relative movement between the piston and the cylinder during relative movement of the auxiliary sill structure and the center sill structure, and means metering movement of said liquid during relative movement of the piston and the cylinder.

28. A cushion mechanism for a railway vehicle for absorbing the energy of an impact applied to a coupler thereof comprising, a vehicle body, a center sill structure extending longitudinally of said body and secured thereto, an auxiliary sill structure extending lengthwise within said center sill structure arranged for movements longitudinally relative to said center sill structure, a coupler and a draft rigging carried by each end portion of said auxiliary sill structure, means coupling said draft riggings to said auxiliary sill structure for moving the auxiliary sill structure relative to said center sill structure upon application of an impact to either coupler, a cylinder mounted within said auxiliary sill structure, a piston within said cylinder, a piston rod extending through opposite ends of said cylinder, liquid within said cylinder, a center post structure secured to said center sill structure in abutting relationship with one end of said piston rod, stop means carried by the center sill structure in abutting relationship with the other end of said piston rod, lugs carried by the auxiliary sill structure engaging opposite ends of said cylinder preventing longitudinal movements of the cylinder relative to the auxiliary sill structure, and said cylinder having grooves therein controlling the velocity of flow of the liquid from one side of the piston to the other to cushion movements of the auxiliary sill structure relative to the center sill structure.

References Cited by the Examiner UNITED STATES PATENTS Meyer et a1. 21343 LEO QUACKENBUSH, Primary Examiner. JAMES S. SHANK, Examiner.

Disclaimer 3,186,562.J0lm A. Angold, Topeka, Kans. FREIGHT CAR UN DER- FRAME 'WITH HYDRAULIC CUSHIONING. Patent dated June, 1, 1965. Disclaimer filed N 0v. 26, 1965, by the assignee, Keystone Railway Equipment Company. Hereby enters this disclaimer to claims 18, 19, 22, 23, 24, 25, 2'6', 27 and 28 of said patent.

[Ofiicz'al Gazette May 10, 1966.]

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