US3082708A

US3082708A - Long travel cushion body railroad car

Info

Publication number: US3082708A
Application number: US25128A
Authority: US
Inventors: William H Peterson
Original assignee: Pullman Inc
Current assignee: Pullman Inc
Priority date: 1960-04-27
Filing date: 1960-04-27
Publication date: 1963-03-26
Anticipated expiration: 1980-03-26

Description

March 26, 1963 w. H. PETERSON LONG TRAVEL CUSHION BODY RAILROAD CAR 5 Sheets-She Filed April 27, 1960 March 26, 1963 w. H. PETERsoN 3,082,708

LONG TRAVEL CUSHION BODY RAILROAD CAR Filed April 2'?. 1960 5 sheets-sheet 2 March 26, 1963 w. H. PETERSON 3,082,708

LONG TRAVEL CUSHION BODY RAILROAD CAR Filed April 27. 1960 5 Sheets-Sheet 3 March 26, 1963 lw. H. PETERSON LoNG TRAVEL CUSHION BonY RAILROAD CAR 5 Sheets-Sheet 4 Filed April 27, 1960 z Ue rz Zar Hf Zens'm March Z6, 1963 w. H. PETERsoN 3,082,708

LONG TRAVEL CUSHION BODY RAILROAD OAR Filed April 27. 1960 5 sheets-sheet 5 V l" w( Q N 1""15 Q N R1' I S1 Q yl l i -1 LNX N s N N N N QO w 5 @o N 1 N :w s O O I w i NN 1 g w gg N @1| N N I N `Sf`- I I Bauen/507" N gz'llmgfee P5012/ @y WM mymw United States Patent O 3,082 708 LONG TRAVEL CUSHIO BODY RAILROAD CAR William H. Peterson, Homewood, Ill., assignor to Iullman Incorporated, Chicago, lll., a corporation of Dela- Ware Filed Apr. 27, 1960, Ser. No. 25,128 3 Claims. (Cl. 10S-392.5)

My invention. relates to a long -travel cushion body railroad car, and more particularly, to a railroad car having its body cushioned with respect to its underframe for practice of the principles described in my application Serial No. 856,963, tiled December 3, 1959, now Patent No. 3,006,436, granted October l0, 1961 (the entire disclosure of which is hereby incorporated herein by this reference.)

Lading damage resulting from coupler impacts and the claims resulting therefrom have always been a major problem for the railroad industry, but during recent years the problem has been greatly magniiied by increased service speeds with the resulting increase in severity and frequency of coupler impacts between freight cars. Furthermore, statistics show that most lading damage claims can be attributed to damage caused by coupler impacts, such as those incurred during switching operations.

My application Serial No. 856,963 discloses a basically new approach to the protection of lading in transit on railroad cars, which is particularly elective in providing damage free protection to the class of lading that is most critical from the damage claim standpoint, that is, commodities packed in fibre or cardboard boxes or cartons.

As disclosed in my application Serial No. 856,963, during any impact situation, changes in the absolute velocity of the lading (which are normally caused by stopping and starting of the car, and by impacts against the car couplers during transit) are eliected by adding or s-ubtracting kinetic energy to the lading through the frictional forces acting between the lading and the car as Well as the pressure of the car end wall on the lading (the car end wall involved depending upon which car coupler is initially subjected to the longitudinal shock, and whether the shock is in buff or in draft). My said application discloses that damage free lading protection against longitudinal impacts (that is, impacts applied against the car couplers) can be obtained if there is interposed between the couplers and the car body containing the lading a cushioning device or arrangement having a cushion travel sufficient in capacity and length that the absolute velocity of the lading is changed to that required by the Law of Conservation of Momentum 'for Inelastic Bodies by employing to a substantial degree the frictional forces acting between the lading and the car, as distinguished from the compressive forces applied to the lading by the car end wall. This novel approach involves, among other things, extending the time of closure of the cushioning device employed sufficiently so that the changes that must occur to the absolute velocity of the lading (by reason of the aforementioned Law of Conservation of Momentum) occur to the lading substantially as a unit. The length of travel found essential to U.S. railroad practices is in the range of -40 inches, and preferably is on the order of 30 inches. i

I have found, as disclosed in my above mentioned application, that a cushion travel in this range permits the inherent stability of the load and the friction between the lading and the car body to act as substantial factors in creating the lading acceleration (either positive or negative) necessary to achieve the absolute velocity dictated by the aforementioned Law of Conservation of Momentum, without developing within the lading the destructive compressive forces which cause lading damage.

3,082,708 Patented Mar. 26, 1963 ice The invention of my application Serial No. 856,963 is applicable to a wide variety of railroad car arrangements, including cars especially designed for piggyback freight container sys-tems of handling freight as well as the familiar boxcars, flatcars and other standard designs. Several examples are illustrated in said application, two of them relating to the well known cushion underframe arrangement and a cushion body arrangement.

As is well known in the art, cushion underframe cars employ as part of the underframe a sliding sill or draft and bufiing col-umn, which moves (under the impe-tus of coupler impacts) with respect to the car body, car bolsters, trucks, and brake rigging to effect the cushioning action required. Cushion body cars employ a body that is separate from the car underframe structure, and the car underframe structure (which includes the bolsters adapted for connection to the car or trucks), the trucks supporting same, and the brake rigging move with respect to the body under the impetus of the coupler impact to eiect the cushioning action required. t

The present application is directed to the cushion body car disclosed in said application Serial No. 856,963, and includes improvements over the specific form of car illustrated in that application.

A principal object of the present invention is to provide a railroad car of simplified arrangement incorporating the principles disclosed in my application Serial No. 6,963, which is suitable for use in making the familiar boxcar, atcar, gondola car and the like, as well as all special car arrangements, such as those specially designed for piggyback service. t i

A further principal object of this invention is to provide a simpliiied car including an underframe that consists of essentially only a center sill and bolsters, which when associated with a cushioned car body in accordance with this invention, will provide the surprising results of my said application Serial No. 856,963; to provide a novel cushion pocket and long travel cushion device for railroad cars that insure the cushioning action contemplated by my application Serial No. 856,963; to provide a novel car body underframe design adapted for use as a foundation for car bodies which is especially adapted for practicing the invention of my said application Serial No. 856,963; and to provide a simplified car design that is inexpensively manufactured and is well suited for carrying out the principles of the invention described in my application Serial No. 856,963.

Other objects, uses and advantages will be obvious or become apparent from a consideration of the following detailed description and the application drawings.

In the drawings:

FIGURE 1 is a diagrammatic perspective View illustrating the principal features of a cushion body railroad car in accordance with this invention, with the conventional car body structure, car trucks and railroad safety equipment omitted to facilitate illustration;

FIGURE Z is a cross-sectional View substantially along line 2 2 of FIGURE l;

FIGURE 3 is a diagrammatic perspective view substantially along line 3 3 of FIGURE l;

FIGURE 4 is an enlarged perspective View illustrating the manner in which a preferred form of cushioning unit is applied to the `car structure shown in FIGURE 1;

FIGURE 5 is a diagrammatic fragmental perspective View illustrating the roller arrangement that is applied between the car body underframe and center sill structure of the embodiment of FIGURE l;

FIGURE 6 is a diagrammatic cross-sectional view approximately along line 6--6 of FIGURE 4;

FIGURE 7 is a diagrammatic sectional view substantially along line 7-7 of FIGURE l;

FIGURE 8 is a diagrammatic cross-sectional View substantially along line 8 8 of FIGURE l;

FIGURES 9 and 10 are diagrammatic perspective views, in section, illustrating one embodiment of a specific long travel hydraulic cushion device that may be used in practicing my invention, and showing it in extended and contracted positions, respectively; and

FIGURE ll is an enlarged sectional view of the cushion unit of FIGURES 9 and l0, positioned as shown in FIG- URE 9, illustrating the direction of the hydraulic liquid flow on initiation of the contraction stroke of the hydraulic unit.

However, it should be understood that the specific disclosure which follows is for the purpose of complying with section 112 of Title 35 of the U.S. Code and the appended claims should be construed as broadly as the prior art will permit consistent with the disclosure herein made.

GENERAL DESCRIPTION Referring now to FIGURE l, reference numeral 10 generally indicates a car structure conforming to the invention described in my application Serial No. 856,963, which is of the cushion body type, and comprises a center sill structure 12 connecting spaced bolster structures 14, and a body underframe structure 16 which is mounted for movement with respect to the center sill structure 12 and bolster structures 14.

Only one of the bolster structures 14 is illustrated and the conventional car trucks have been omitted, but as well known in the art, bolster structures 14 are operatively secured through a conventional center plate and kingpin arrangement to the trucks.

For purposes of this invention, any type of car body structure may be mounted on or associated with the body underframe structure 16, whether of (for instance) the boxcar, atcar, gondola, passenger, or special piggyback or freight container car type, and for simplicity of illustration, only the details of the body underframe are shown.

As indicated in FIGURES l, 2 and 5, the body underframe 16 includes spaced side sills 18 that ride on rollers 20 journalled at the ends of the respective bolster structures. In accordance with this invention, the underframe 16 is supported by center sill structure 12 only through the rollers at the ends of the bolster structures 14.

The side sills 18 of the body underframe 16 are joined together by end cross bearer structures 22 (only one of which is shown) and intermediate cross bearer structures 24, which are formed to define

openings

26 and 28, respectively, through which the center sill structure 12 extends without contacting or resting on any of the cross bearer structures.

In the specific embodiment illustrated, a long travel cushioning arrangement having the characteristics contemplated by my said application Serial No. 856,963 is interposed between the center sill structure 12 (which together with `bolster structures 14 actually forms the underframe of the car) and the body underframe 16 where indicated by reference numeral 30 (see FIGURES l and 4). hydraulic cushioning device 32 received between the two Z members 34 that are employed to make up the center sill structure 12, and applied between spaced lugs 36 that are fixed in spaced pairs to the respective Z members 34. The cushion device 32 includes

follower members

38 and 40 which bear against the lugs 36 as well as spaced stop or key members 42 that are fixed to the respective intermediate cross bearers 24 and operate between the lugs of the respective pairs of spaced lugs 36.

The remainder of the car lil (other than the structure illustrated) need include only those structures required to make operative the conventional safety and other apparatus required by A.A.R. regulations, some of which are diagrammatically indicated in the drawings such as the hand brake 43, and a platform 44 for operating same, couplers 45, uncoupling devices 46, and suitable ladder The cushioning arrange-ment 30 includes a and 7).

arrangement which may include the hand hold generally indicated at 47. The hand brake and platform for operating same may be secured to the simplified end sill structure indicated at 48 in FIGURE 1 and the uncoupling devices should be carried by or connected to the center sill structure. The brake rigging, trainline conduiting 49, and other equipment needed to make the brake rigging operative are preferably entirely secured to the center sill structure rather than to the car body, though this may be done in any suitable manner (some of these components being diagrammatically illustrated in FIGURES l The uncoupling device at the brake end of the car may be supported by end sill structure 48, and at the 'other end of the car, the uncoupling device may be supported by a similar end sill structure 48 (not shown).

The hydraulic cushion device 32 is received in a cushion pocket 50 (see FIGURE 4) defined by the center sill structure 12 and the spaced pairs of lugs 36 carried by same. Device 32 generally comprises (see FIGURES 9 and 10) a cylinder 52 and a piston head 54 having xed thereto a tubular piston rod 56 which projects outwardly of the cylinder 62. The heads or closures 58 and 60 form the cushion followers 38 and 4t), respectively, that are held against the spaced pairs of lugs and stop members by high strength compression springs 62.

The hydraulic unit 32 is designed to have a cushion travel or closure distance in the range of 2.0-40 inches, and preferably on the order of 30 inches, and the body underframe 16 is arranged to permit this amount of movement in either direction when longitudinal impacts are applied to the car 10 in service. The stop members or keys 42 project through the top of the center sill structure 12, through appropriate slots 64 which likewise are proportioned to permit the above specified movement of the stop members with respect to the center sill structure. Unit 32 is double acting, as it affects the cushioned transfer of impacts applied to either end of the car 10, and it preferably is provided with a substantially constant force travel closure characteristic.

In service, when an impact occurs, for instance, in the direction of the arrow 66 of FIGURE 10, the center [sill structure 12 and the bolster structures 14 fixed thereto (together with the car trucks) move under the impetus of the impact against one end of the hydraulic device 32 to move the latter from its extended position of FIG- URE 9 to its contracted position of FIGURE 10. As the hydraulic device moves to its contracted position of FIG- URE 10, hydraulic liquid is forced through orifices `to dissipate in the form of heat lsubstantially all of the energy that is involved in the so vcalled impact effect when a car impacts against, or is impacted by, one or more other cars; the cushion device also adds to or subtracts from the Vbody and lading carried `by the underframe 16 the energy of the impact that is to be acquired by or lost as a result of the impact (depending upon the condition of impact).

Under the impact conditions of IFIGURE 10, the impact has been applied to the coupler 45 at the left hand end of the car shown in FIGURE 1 (which is keyed to the center sill structure 12 through appropriate draft gear) and this forces the left hand pair of lugs 36 against the hydraulic device closure member 60 forming the follower 40, which presses the device 32 against the right hand stop member 42, as indicated in FIGURE 10. Due to the inertia of the body underframe 16 and the body structure and lading carried thereby, the absolute motion of the body and lading is initially unaffected by the impact, but the pressure on the hydraulic device -follower 38 acting on the right hand stop member 42 gradually transfers the kinetic energy of the impact to the `body underframe 16 and the body structure and lading carried thereby (by reason of the pressure against the right hand stop member 42). The cushion device continues to close until its parts have the operative relation indicated by FIGURE 10, at which time the car body and lading have the ultimate velocity dictated by the aforementioned Law of Conservation of Momentum.

After the impetus of an impact has been dissipated and the kinetic energy involved in the impact has been transferred to the body and lading through the cushioned device, springs 62 acting in tandem on heads 58 and 60 restore the car body and lading to its normal central position with respect to the car center sill structure 12.

When the direction of impact is in the opposite direction, the functioning of the hydraulic device 32 is the same, though the forces involved act in opposite directions. Draft forces are handled in a similar manner, though the operation of the cushion device will depend upon the direction of the draft force, as will be understood by those skilled in the art.

The shape of the body underframe sill members 16 and the complementary shape of rollers 20 (see FIG- URE 2) insures that the body underframe will be properly centered during relative movement between body underframe and the center sill structure during dissipation of impacts.

Specific Description r[he center sill structure 12 is preferably of the standard Z26 type and thus includes the two Z members 34 welded together as at 7@ along the length of the center sill structure. It is the Z members 34 `when united as shown that define the familiar inverted channel-shaped configuration of the `center sill structure 12, which thus has an open bottom 72 and laterally extending flanges 74. The Z members may be initially formed as at 76 to define the respective slots 64 when they are joined together. The center sill structure 12 may be provided at its ends with the customary draft gear pocket, lugs, draft gear, yoke, coupler key and the like for operatively mounting coupler 45 within the ends of the center sill structure, as will be immediately apparent to those skilled in the art. Strikers 7S, which may be formed in any suitable manner, form the ultimate ends of Ithe center sill structure 12.

The bolster structures 14 are essentially of the standard box type including spaced webs 80 (see FIGURES 1 and 2) fixed as by welding between upper and

lower cover plates

82 and 84. As indicated in FIGURES 1 and 2, the top cover plate 82 extends across the width of the car, while the bottom cover plates 84 extend between the edges of the center sill structure flanges 74 and the respective other ends of the bolster structures, the webs S0 being fixed at their inner ends to the center sill structure, as by welding; top and

bottom cover plates

82 and 84 are fixed to the portions of the center sill structure that they abut, as by welding. As indicated in FIGURE 2, a conventional center plate structure 86 is afiixed to sole plate 87 and the center sill structure by appropriate rivets S8. The center plate structure extends across the bottom of the center sill structure and forms the upper center plate of the conventional pivotal connection lbetween railroad car body bolsters and railroad car truck holsters, as is well known in the art. The kingpin connection between the upper and lower center plates may be effected in any conventional manner.

The bolster structures in the form illustrated include a side bearing 89 of a conventional type braced by side bearing brace plate 91 welded between webs 80 and the respective bottom plates 84.

At the ends of the bolster members 90l defined on either side of the car by the webs 80 and

plates

82 and 84, the webs S0 and the

plates

82 and 84 are welded to an end plate structure 92 defined by a pair of plates 94 (see FIGURES 2 and 5) rigidly afiixed to each other by welding, appropriate bolts 95, and brace plate 97 (the latter also being welded to bottom plate 84). The end plate structure 92 has fixed thereto frame 96 which together with the plate structure 92 journals shaft 98 which rotatably mounts the respective rollers 20. Frame is only diagrammatically illustrated and may take tue form of end member 99, afiixed to the respective plate structures 92 as by being welded to side members 100 which are in turn welded to .the respective plate structures 92.

Rollers 20 are preferably journalled so that they are coplanar in a substantially horizontal plane (that is a plane parallel to the center sill structure 12) and the upper portions of their peripheries are tangent with a common generally horizontal plane.

The conventional brake rigging and trainline connections in accordance with this invention are affixed to or supported only by the center sill structure 12 in any suitable manner, though preferably the brake and other equipment are applied to the center sill structure 12 in the area of bays `103 and 105 defined vby the body underframe cross bearers 22 and 24., leaving bay 107 free for use in applying the cushioning arrangement to the car. Thus, the AB valve 102, the brake cylinder 104, and the auxiliary reservoir 106 may be 4suspended from the sides of the center sill structure 12 in bay `105 by

appropriate bracket structures

107 and 108, respectively. 'Ihe dead lever arm and similar members of the brake rigging may be affixed to the underside of the center sill structure in any suitable manner, as by appropriate brackets 109 (see FIGURE 7) affixed to the center sill structure, though the dead lever arm is preferably mounted in the area of bay 105. The brake rod (see FIG- URES 2 and 7) that is preferably connected to hand brake 43 extends through opening 26 of the adjacent end cross bearer structure 22 (see FIGURE 3) and also through openings 117 formed in the webs 80 of one of the ybolster members 90. The rigging may employ a center rod and other connections which may be applied yto the center sill structure in any suitable manner.

The trainline 49 is afiixed to the center sill structure by employing suitable bracket devices 113 as and where desirable along the length of the trainline. The trainline 49 should be arranged to have the usual connections with the brake rigging and trainlines of adjacent cars, and in the embodiment illustrated passes through holes 119 in web 80 of one of the bolster members 90 (see FIGURE 2).

The end sill structure 48 carried by the center sill structure 40 may comprise channel members 110 and 111 Welded together and to the center sill structure and adjacent bolster structure 14 in any suitable manner. Likewise, the ladders, brake, uncoupling device and the like may be secured to the end sills as desired. Hand brake wheel 43 is applied to vertical plate structure in any suitable manner to make operative any conventional hand brake arrangement.

The body underframe 16 is formed by the side sills 18, which are of channel-shaped section defining upper and lower fianges 114 and 116 separated by web 118. In the area of the bolster members 90, a wear plate 120 is affixed to the upper flange 114 which actually rides on the respective rollers 20.

Rollers 20 are made frustoconical in configuration to conform to the taper of the upper flanges 114 of sills 18. The oppositely directed taper of rollers 20 of each bolster structure 14, and the sill webs 118 keep the body underframe 16 in proper alignment with the center sill structure 12.

The end cross bearers 22 (see FIGURE 3) of the underframe 16 each comprise cross bearer members 122 defined by upper and

lower cover plates

124 and 126 affixed to the upper and l-ower edges of web 123. At their outer ends,

plates

126 and 124 and web 12% are welded to the respective sills 18, while at their inner ends, they are affixed to a vertical end plate 130, which depends below the bottom plate 126 and is afiixed to depending web 132 which is also welded to bottom plate 126. Reinforcing plates 134 and 136 are affixed to the lower edges of plate 132, and plates 136 of each cross bearer member 122 are rigidly joined by reinforcing plate 13S which in turn is reinforced by channel member 140.

The top plate 124 of the end cross bearer structures extends the width of the car and is reinforced by having welded thereto channel member 142, which is fixed at its respective ends to the respective side sills 16.

The end cross bearer structures 22 thus define a wheel well 144 to insure adequate clearance from the truck wheels at all possible positions of the cross bearer structure 22 with respect to the center sill structure 12. The dashed line position of truck wheel 145 in FIGURE 3 shows the wheel positioning relative end cross bearer structures 22 on straight track with truck spring fully compressed, while the broken line showing of wheel 145 indicates the position of the wheel with the trucks at maximum turned position on a 175 foot radius curve with truck springs fully compressed.

The intermediate cross bearer structures 24 (see FIG- URE 8) comprise cross bearer members 150 defined by top cover plate 152, bottom cover plates 154 and web 156. The top and bottom cover plates and the web 156 are afiixed together and to side sills 18 as by welding. Plate 152 extends the width of the car and is reinforced by channel member 158 which has its ends affixed as by Welding to the respective side sills 18. Adjacent the center sill structure 12, and on either side thereof, the intermediate cross bearers are joined by longitudinally extending tie plates 160 provided with upper and lower reinforcing

plates

161 and 162 which are secured to the top andbottom cover plates, respectively, as by welding. The bottom cover plates are joined underneath the center sill by reinforcing plate 164 that is in turn reinforced by channel member 166.

The intermediate cross bearer structures are also joined together by stringers 170, which are fixed between the respective cross bearer top cover plates 152 and channels 150 as by welding. Spaced reinforcing channel members 172 are fixed between the respective side sills 16 across the cushion pocket 50, and shear plate 174 is welded between the respective channels 172 and stringers 170. The side edges of the shear plate 174 are turned downwardly as at 176 for strengthening purposes.

The stop members 42 of the respective intermediate cross bearer structures are welded between the respective plates 164 and 152 (see FIGURE 4).

It will therefore be seen that the intermediate cross bearer structures not only perform the usual cross bearer function, but also are rigidly united together longitudinally of the cushion pocket, and further, the side sills of the underframe are likewise rigidly united together across the center of cushioned pocket. This insures against deformation of the underframe structure in spite of the relatively light framing arrangement employed.

The channel members 172 and downturned edges or anges 176 of shear plate 174 provide the necessary edge stability for the shear plate to transmit cushion forces out to the sides of the car body without buckling. Since cross bearer members 156 are designed primarily for vertical bending strength, the illustrated shear plate arrangement is necessary to supply to these members the horizontal bending strength required when the cushion device operates as a result of coupler impacts.

The side sills 18 of the body underframe are preferably joined intermediate the end cross bearer structures and the intermediate cross bearer structures by appropriate channel members 180 which thus form cross tics. The underframe 16 may also include decking side sills 182 that are aflixed to the top yfianges 120 of the side sills 16 as well as to the ends of the

channels

142, 158, 172 and 180, and decking end sills 181 affixed to sills 182. In between these channels and parallel thereto may be mounted appropriate steel deck forming members of any suitable type to provide decking 184, appropriate decking supporting stringcrs 183 being employed where necessary or desirable.

The cushion device 32 is supported in the cushion pocket `50 by carrier plates 190 secured in place as by bolts 192. As seen in FIGURE 6, the ends 194 of the carrier plates and guide plates 195 fixed to the respective Z members 34 guide the hydraulic unit 32 in its contraction and extension strokes.

Hydraulic Cushion Device The hydraulic cushion device 32 is preferably of that type described in my copending application Serial No. 782,786 led December 24, 19'58, now Patent No. 3,035,- 827, granted May 22, 1962, the entire disclosure of which is hereby incorporated herein by this reference (the improved device disclosed in my later filed application Serial No. 9,785, filed February 19, 1960, now Patent No. 3,035,714, granted May 22, 1962, may also be employed, and the disclosure of this application is also incorporated herein by this reference).

The device 32 is a dissipative energy system type constant force travel long travel cushioning mechanism arranged to transfer and dissipate substantially all kinetic energy imposed on the center sill structure 12 by draft and buff forces applied to the car couplers (in excess of the minor amounts absorbed by the draft gear and return springs of the device 32). This is to be distinguished from conservative energy system type cushioning devices that merely store the energy on impact and return it in the form of oscillations. As described in my application Serial No. 856,963, device 32 is a 100 percent efiicient cushion travel device meaning that it transfers and dissipates the required energy with minimum travel and with no recoil.

ln other words, and as specified in said Peterson application Serial No. 856,963, the cushioning device 32 should have a travel of from about 20 to about 40 inches, or its equivalent, and be characterized by its ability to dissipate a su'icient amount of the energy of impact (other than that portion of such energy needed to recenter the cushioning device), either on closing of the device, or on closing and return of the device (note that the restricted flow of hydraulic liquid in cushioning device 32 on its return to normal is energy dissipating and thus cushion 32 has controlled recoil), so that the major portion of the remaining energy of impact is transmitted as kinetic energy to the load. Thus, in essence this makes the cushioning device 32 a dissipative energy system cushion as opposed to a conservative energy system cushion that stores and returns substantially all kinetic energy applied to it, although such dissipative energy system cushion should have sufficient energy storing and return characteristics to return the cushion and the body underframe to neutral or recentered position.

By employing the long travel cushioning device 32, the time required for the transfer of, for instance, the momentum of a striking car to a struck car 10 is prolonged sufliciently to achieve the aforementioned benefits that are disclosed in my said application Serial No. 856,963.

The device 32 generally comprises the aforementioned tubular cylinder 52 in which piston head 54 is reciprocably mounted, tubular piston rod 56 affixed to piston head 54, and invaginating tubular member or boot 200 connected between the tubular cylinder 52 and the tubular piston rod 56, and the helical compression springs 62 extending between closure members 58` and 60i of the tubular cylinder 52 and tubular piston rod 56, and a spring seat 202.

The closure member 58 and tubular cylinder 52 carry a metering pin 204 that is reciprocably received within the bore 206 of the tubular piston rod 56. The metering pin. 204 preferably is provided with a guide member 208 at its projecting end when the cushion device of my application Serial No. 782,786 is employed.

The internal surface 210` of tubular cylinder 62 is formed 1n any suitable manner as at 212 (see FIGURES 9-11) to receive three

snap rings

214, 216 and 218. The snap ring 214 serves as a stop for piston head 54 when the device is in its extended position of FIGURE 9, while the snap rings 216 and 218` hold in place a piston rod guide member 220 to which one end 22 of the invaginating boot or tubular member is secured by a suitable clamp 224i. The other end 226 of the boot or tubular member is turned outside in, and is secured to the external surface 228 of the piston rod 66 by a suitable clamp 230.

The device 32 is charged with hydraulic liquid as described in said copending application Serial No. 782,786 to completely ll the space defined by the tubular cylinder S2, the tubular piston rod 56, `and the invaginating boot or tubular member 200. When in use, the device 32 has the normal positioning indicated in FIGURES 9 and 11, and in the illustrated arrangement, the device 32 engages the lugs 36 and stops 42 at both ends of, for instance, cushion pocket S0, as previously described. When the center sill structure 12 receives a shock either in buff or draft, either the tubular member 52 will commence movement to the left of FIGURE 9 or the tubular piston rod 56 and piston head 54 will commence movement to the right of FIGURE 9, or possibly both movements may occur. In any event, as the device 3-2 retracts under the force being pushed, the metering pin 204 displaces hydraulic liquid contained within the tubular piston rod S6 and the piston head 54 causes a hydraulic liquid fiow through its orifice 232 through which the metering pin extends. As shown, metering pin 204 is provided with a tapered surface 234 that preferably is designed to provide a constant force travel characteristic as the hydraulic cushion 32 contracts under the shock opposed on it; that is, the arrangemen-t is such that for every unit of travel, the cushioning device provides a substantially constant cushioning effect.

As indicated in FIGURE 1l, the oil ow then initiated is from the chamber 236 on the high pressure side of the piston head 54 through the orice 232 and into the bore 206 of tubular piston rod 56, thence radially outwardly of the piston rod 56 through orifices or ports 238 of the tubular piston rod 56. As the hydraulic liquid within the tubular piston rod is displaced by the metering pin 204, it likewise moves through the ports 238, as indicated by the arrows in FIGURE 11. Metering pin guide member 26S is formed with relatively large apertures 211,0` to permit a free flow of hydraulic liquid during movement of the metering pin.

The hydraulic liquid flow through ports 238 is under relatively high velocity and creates great turbulence in the chamber 242 that is formed by the space between the tubular piston rod guide member 220 and the piston head 54. This gre-at turbulence is caused at least in part by the radially directed o-w of hydraulic liquid impinging directly against the inner surface 21d of tubular cylinder 52, and is responsible for dissipation of much of the kinetic energy of the hydraulic liquid in the form of heat.

As the contraction of the hydraulic cushion device 32 proceeds, the high pressure chamber 236 is reduced in volume by the advancement of the piston head 54 toward the tubular cylinder closure member S8. The hydraulic liquid passing through orifice 232 lis the chamber 242 behind the piston head 54, `while a volume of hydraulic liquid equivalent .to 4that displaced by the total entry into the liuid chamber of the piston rod 56 passes through apertures 244 of guide member 22()l into the space 246 enclosed by the invaginating boot or tubular member 200 which inflates or expands and rolls to the position suggested by FIGURE l0. The apertures 244 are relatively large in cross-sectional area which provides and permits the relatively large volume and consequently low pressure hydraulic liquid flow from chamber 242 to space 246. This avoids generation of any appreciable compressive force on the relatively slender metering pin and prevents any possibility of it buckling.

After the shock has been fully dissipated, the compression springs 62, acting in tandem, return the hydraulic cushioning components to the initial extended position of FIGURES 9 and ll. During this movement under the action of the compression springs, the oil ilow illustrated in FIGURE 1l is reversed, and invaginating tubular member or boot 20d deflates and returns to the position of FIGURES 9 and l1, thereby insuring that the hydraulic liquid displaced by the piston head 54 and piston rod 56 is restored to its normal operative locations.

It will thus be seen that device 32 is composed of few and simple components. Furthermore, all sliding` or dynamic seals are eliminated and instead static or stationary seais are employed throughout the device 32. Thus, the ilexible tubular member 200 is interposed between the piston rod 56 and its guide member 220, and I contemplate that at the ends of the cushion device, static seals such as welded joints or sealing rings held under pressure are to be employed where indicated at 249.

Moreover, all kinetic energy applied to the cushion device, with the exception of the small potential energy stored in the return springs 72, is either dissipated in the form of heat by the passing of the hydraulic liquid through orice 232 and the turbulence in chamber 242, or is transferred as kinetic energy (positive or negative, depending on the condition of impact) to the struck car with its load.

Reference may be had to said copending application Serial No. 782,786, for a more specific description of the speciic unit illustrated. It may be added, however, that the tapering surface 234 of the metering pin 204` extends between points 250 and 252 (see FIGURES 9 and 1l) and that the contour of tapered surface 234 in the illustrated embodiment is designed from the relationship wherein AX is the orice area of any position x (see FIG- URE ll) along the totai nominal stroke d (the length of the tapered surface 23d), and AO is the initial oriiice area defined by the orice 232 at the beginning of a stroke, in the case Where a completely rigid body is being cushioned from impact. While in most cases and for a given car Weight this assumption will result in a reasonably e'- cient design, small alterations can be readily made to this shape to give it a closer approach to the optimum of constant force travel `characteristic for a given situation after a few experimental trials. However, the shape given by the above formula is the best starting point. Furthermore, it is usually possible to obtain a reasonably eliicient design by approximating the curved shape given by the above expression as by calculating a series of spaced cross-sectional areas so determined by straight tapers, if this facilitates manufacture. Moreover, the pin could be contoured so as to provide for the desired stroke which Would give a substantially higher force travel characteristic than that throughout the normal stroke, in order to protect against overloads or other unusually severe condition. In fact there is no limit to the possibilities of how the pin might be shaped to suit special situations or the application of existing knowledge of this art but in any event, I prefer that, for use in cars such as car 10i, unit 32 be designed for handling the maximum impact and energy absorption requirements that it is apt to be subjected to. Thus, the device 32 should be so designed that when metering pin 264 closes orifice 232 at point 252, the device will have absorbed the maximum impact that can be applied to it.

The orifice areas referred to above are the orifice areas of oriiice 232 minus the cross-sectional area of the metering pin at any given position along the stroke of the metering pin.

The components of the unit 32 of the illustrated embodiment may be formed from any suitable materials, boot 20d being formed from suitable impervious, flexible, rubber-like material with special additives for low temperature exibility and clamps 224 and 23)v being of the type of clamp sold under the trademark Punch-Lok, made and sold -by the Punch-lok Company of Chicago, Illinois. Clamps 224 and 230 as well as O-ring seal 255 of piston rod guide 220 provide the overall static seal desired between the piston rod 56 and the cylinder 52.

The unit 32 of the illustrated embodiment is preferably charged with the high viscosity index oil sold yby Shell `Oil Company under the trade designation Aeroshell No. 4, as this oil desirably has a relatively small variation in viscosity between the extremes of minus 60 degrees F. and 150 degrees F.

The hydraulic liquid when the device 32 is in fully extended position is under very little pressure, perhaps no more than 2 p.s.i., but even though the pressures in the high pressure chamber 236 may rise to as much as 8,000 p.s.i. as when the device is employed in railroad cars, such as car 10, to cushion buff and draft forces, the maximum pressure within the invaginating boot 200 (when fully inated) is believed to be about p.s.i. Boot 200 stretches about 100 percent when fully initiated. Units 32 can be designed for operating pressures up to the limit of the yield strength of cylinder 52 and the device of FIGURES 9-11 when employed as indicated, is capable of handling kinetic energy on the order of a million foot pounds, depending, of course, on the specific design required for a specific purpose. Units 52 will thus easily handle mile per hour impacts when applied to, for instance, the railroad car structures of FIGURES 1-8.

Distinguishing Characteristics of t/ze Invention It will thus be seen that I have provided a highly simplified railroad car structure that not only is especially adapted for providing the benefits of the long travel cushioning action contemplated by my application Serial No. 856,963, but also has a number of important distinguishing characteristics of its own.

Forinstance, the basic arrangement of car 10 avoids the coupler angling problem that can arise in connection with cushion underframe cars. In the car of this application, the trucks are pivoted directly to the center sill at bolsters 14, and thus the distance lbetween the truck kingpins and the pulling faces at the respective coupler locations does not change materially as a result of coupler impacts. However, in cushion underframe cars employing the invention of my application Serial No. 856,- 963, the center sill slides with respect to -the car bolsters, with the truck being pivoted to the bolster, which means that it may be necessary to provide for a total of sixty inches of movement of the sliding sill with respect to the trucks and their kingpins. Such a requirement for cushion underframe cars is particularly acute for long car arrangements because coupler angling on curves will be excessive, particularly when coupler impacts are occasioned on curves.

Moreover, since all brake rigging and other car equipment necessary to make the brake rigging operate are attached to center sill structure 12, the car body structure that is carried by underframe structure 16 may be made readily removable to adapt cars 10 for use in practicing container systems of handling freight. Thus, the car body that is applied to underframe 16 may be appropriately designed for crane or fork lift handling between the car 10 and a highway vehicle and suitable latch devices employed to latch the container body to underframe 16. Also, by omitting underframe 16, it is possible to form a freight container carrying car of the type disclosed in the copending application of Kenneth J. Austgen, Serial No. 9,135, -filed February 16, 1960 (the disclosure of which is hereby incorporated herein tby this reference). It will therefore be seen that my invention has versatility aspects that markedly distinguish it from conventional apparatus.

Furthermore, my car arrangement permits uncoupling devices to be mounted in the conventional manner, which is an advantage over cushion underframe cars as the sliding sills of the latter, which carry the couplers, require uncoupling devices of a special design to accommodate the relative movement between the coupler and its uncoupling device.

An important feature of the center sill structure herein disclosed is the simplication that is permitted by reason of the fact that no vertical loads are applied to the center sill structure at points spaced from the bolster structures 14, except for reaction forces resulting from the operation of cushion device 32. Thus, it will be noted that the weight of the lbody underframe 16 and the lading carried thereby is applied directly to the car trucks through the bolster structures.

Furthermore, the rigid interconnection of the intermediate cross bearer structures 24 and the side sills of the :body underframe between them, across and along the cushion pocket, provides an unusually rugged reinforcement against deformation during operation 0f the cushion device.

The natural shape of the center sill structure provides a housing for the cushion device, and the latter is made leak free by the use of static seals throughout and positioning the invaginating boot 200 at a point remote from high pressure hydraulic liquid.

The importance of the static seals in device 32 lies in the fact that conventional sliding seals, such as those customarily found in hydraulic piston and cylinder arrangements are not only exposed to high pressure hydraulic liquids, `but are peculiarly susceptible to damage by foreign matter. For instance, sliding seals customarily engage exposed parts such as a piston rod, that extend from the lcylinder of a hydraulic device, and since the oily surface of the piston rod quickly collects foreign matter, which may include hard particles, such as sand or pieces of metal, these will be drawn against and under the seal on retraction of the rod, with the result that the seal is eventually formed with a multitude of tears or grooves, each of which forms a path for hydraulic leakage.

In accordance with my invention, the static seals of device 32 effect what amounts to a hermetic seal for device 32, and since the long travel I contemplate makes it possible for hydraulic devices to handle the high pressures involved in `transferring and dissipating the modern high speed coupler impacts, it will be apparent that my invention provides for the rst time a practical and inexpensive, leak free hydraulic cushioning arrangement for railroad cars which is adapted to take full advantage of the natural housing formed by center sills of the type shown in the drawings.

This application is a continuation-in-part of my application Serial No. 797,529, filed March 5, 1959, and my application Serial No. 856,963, led December 3, 1959.

The foregoing description and the drawings are given merely to explain `and illustrate my 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 my disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.

I claim:

1. A cushion body railroad car comprising an underframe composed essentially of a center sill structure comprising a center sill member of channel shaped section disposed with the open side thereof facing downwardly, a bolster structure secured to said center sill structure adjacent each end of the center sill structure, said bolster structures each being operatively connected to a railroad car truck, roller means carried by said bolster structures adjacent each end thereof, said roller means each comprising a roller journalled on the respective bolster structures for rotation about an axis extending laterally of 13 the center sill structure with said rollers having the upper peripheries thereof tangent with a common substantially horizontal plane, a car body underframe structure carried by and riding on said rollers, said body underframe structure being mounted on said rollers for movement longitudinally of the center sill structure, said body underframe structure comprising side sills extending longitudinally of said center. sill structure and engaging said rollers, end cross bearer structures joining said side sills together adjacent the ends of said body underframe structure, and intermediate spaced cross bearer structures joining `said side sills together adjacent the midportion of the body underframe structure, said cross bearer structures being formed to dene openings through which said center sill structure extends, a cushion device mounted within said center sill member between said intermediate cross bearer structures, stop members xed to the respective intermediate cross bearer structures and extending through said center sill member, and lugs ixed to said center sill member and spaced apart longitudinally of said center sill member a distance corresponding to the distance between said stop members, said cushion device being operatively interposed between the respective stop members and lugs, said rollers being frustoconical in configuration and the rollers on opposite sides of the car being directed in opposite directions, with 14 said car body underframe structure side sills in the area thereof engaging the respective rollers being formed t0 substantially complement the configuration of the respective rollers.

2. The railroad car set forth in claim 1 wherein said end cross bearer structures are formed with wheel wells to avoid interference with the truck wheels.

3. The railroad car set forth in claim 1 wherein said cushion device is mounted within said center sill member by supporting same on carrier plates affixed to the lower edges of said center sill member, and including guide plates aixed within said center sill member and in engagement with said cushion device for guiding the movement of same between its extended and contracted positions.

References Cited in the iile of this patent UNITED STATES PATENTS Fitch July 21, 1936 McCatferty et al. Jan. 7, 1958 OTHER REFERENCES

Claims

1. A CUSHION BODY RAILROAD CAR COMPRISING AN UNDERFRAME COMPOSED ESSENTIALLY OF A CENTER SILL STRUCTURE COMPRISING A CENTER SILL MEMBER OF CHANNEL SHAPED SECTION DISPOSED WITH THE OPEN SIDE THEREOF FACING DOWNWARDLY, A BOLSTER STRUCTURE SECURED TO SAID CENTER SILL STRUCTURE ADJACENT EACH END OF THE CENTER SILL STRUCTURE, SAID BOLSTER STRUCTURES EACH BEING OPERATIVELY CONNECTED TO A RAILROAD CAR TRUCK, ROLLER MEANS CARRIED BY SAID BOLSTER STRUCTURES ADJACENT EACH END THEREOF, SAID ROLLER MEANS EACH COMPRISING A ROLLER JOURNALLED ON THE RESPECTIVE BOLSTER STRUCTURES FOR ROTATION ABOUT AN AXIS EXTENDING LATERALLY OF THE CENTER SILL STRUCTURE WITH SAID ROLLERS HAVING THE UPPER PERIPHERIES THEREOF TANGENT WITH A COMMON SUBSTANTIALLY HORIZONTAL PLANE, A CAR BODY UNDERFRAME STRUCTURE CARRIED BY AND RIDING ON SAID ROLLERS, SAID BODY UNDERFRAME STRUCTURE BEING MOUNTED ON SAID ROLLERS FOR MOVEMENT LONGITUDINALLY OF THE CENTER SILL STRUCTURE, SAID BODY UNDERFRAME STRUCTURE COMPRISING SIDE SILLS EXTENDING LONGITUDINALLY OF SAID CENTER SILL STRUCTURE AND ENGAGING SAID ROLLERS, END CROSS BEARER STRUCTURES JOINING SAID SIDE SILLS TOGETHER ADJACENT THE ENDS OF SAID BODY UNDERFRAME STRUCTURE, AND INTERMEDIATE SPACED CROSS BEARER STRUCTURES JOINING SAID SIDE SILLS TOGETHER ADJACENT THE MIDPORTION OF THE BODY UNDERFRAME STRUCTURE, SAID CROSS BEARER STRUC-