US3773187A

US3773187A - Cushioning assembly

Info

Publication number: US3773187A
Application number: US00247594A
Authority: US
Inventors: R Carlson
Original assignee: Miner Enterprises Inc
Current assignee: Miner Enterprises Inc
Priority date: 1972-04-26
Filing date: 1972-04-26
Publication date: 1973-11-20
Anticipated expiration: 1990-11-20
Also published as: CA970330A

Abstract

A cushioning assembly designed to be installed in a draft gear pocket of a railroad car and function as a draft gear. The cushioning assembly has an elongated housing with one closed end wall and a plurality of cylindrical passageways extending lengthwise from the closed end wall. A damped spring unit is slidingly mounted in each of the cylindrical openings with its piston in abutting engagement with the closed end wall. The other end of the damped spring units project outwardly of the housing and are in abutting engagement with a force transfer member extending crosswise to the axis of the cylindrical housing.

Description

O Umted States Patent 1 [111 3,773,187

Carlson Nov. 20, 1973 CUSHIONING ASSEMBLY 3,412,869 ll/l968 Wallace et al. 213 43 [75] Inventor: Robert L. Carlson,Chicago, Ill.

I Primary Exammer-Drayton E. Hoffman [73 Ass1gnee: Mmer Enterprises, Inc.,Chicago, V m Att .jgh Dienner Ill.

[22] Filed: Apr. 26, 1972 [57] ABSTRACT [21] Appl. No.: 247,594 A cushioning assembly designed to be installed in a draft gear pocket of a rallroad car and function asa draft gear. The cushioning assembly has an elongated U.S. housing one closed end and a of cy- 213/223, 267/65 R lindrical passageways extending lengthwise from the [51] Int. Cl. B6lg 9/08 closed end wall A damped Spring unit is slidingly [58] Field of Search 213/8, 43, 223, 22, mounted in each f the cylindrical openings with its 213/40 67, 69; 188/322; 267/65 R piston in abutting engagement with the closed end wall. The other end of the damped spring units project [56] References C'ted outwardly of the housing and are in abutting engage- UNITED STATES PATENTS ment with a force transfer member extending cross- 3,275,164 9/1966 Peterson 213 43 wise to the axis of the cylindrical housing- 3,34l,189 9/1967 Rumsey 213/43 3,682,461 8/1972 Wachenheim 213 43 8 Chums 5 D'awmg F'gures 1 1 ""1 13s V \QG I64 156 48 lSZ CUSHIONING ASSEMBLY BACKGROUND OF THE INVENTION My invention relates generally to a cushioning assembly for use in cushioning shock forces imposed on the coupler of a railway car, and the principal object thereof is to provide a cushioning assembly employing a plurality of parallel mounted damped spring units slidably disposed in a cluster arrangement and coupled together by force transfer means to act in unison.

Due to the large size of conventional draft gear apparatus and the different design parameters for the various draft gear applications, there are a large variety of draft gear types which are not adaptable to high production parts manufacture and to standardization of parts.

One object of this invention is to provide a cushioning assembly that uses a plurality of identical damped spring units which are small enough to be assembled on a high production basis and are of a standard size.

A further object of this invention is to provide a cushioning assembly having a cylindrical housing with a plurality of parallel guide surfaces for slidingly receiving a plurality of standardized damped spring units which cooperate in unison to absorb shock forces imposed on the coupler of a railway car.

A further object of this invention is to provide a damped spring unit which is inexpensive to manufacture, and adaptable to high production assembly techniques.

SUMMARY OF THE INVENTION My invention is directed to a cushioning assembly adaptable for use in cushioning shock forces imposed on the coupler of the railway car, and utilizes an elongated container having a closed end wall and a plurality of parallel passageways extending lengthwise from this end wall. A damped spring unit is slidably supported in each of the parallel passageways. The damped spring units are identical in construction and include a chamber formed lengthwise in the elongated casing, a piston and associated piston rod axially disposed in the chamher with the piston rod extending through an opening at the inner end of the casing in the direction of the closed end wall, and a damped spring means disposed in the chamber for imposing spring and damping forces acting between the damped spring unit casing and the piston. By providing front and rear follower plates and a force transfer means all of the damped spring units will act conjointly in response to draft or buff forces exerted on the railroad car coupler.

DESCRIPTION OF DRAWINGS For a better understanding of this invention, a reference may be made to the accompanying drawings, in which:

FIG. 1 is a fragmentary plan view, partly in horizontal section, depicting one embodiment of a cushioning device embodying the principles of my invention;

FIG. 2 is an end view of the elongated container taken from the left side of FIG. 1 and looking in the direction of the open end;

FIG. 3 is a fragmentary plan view, partly in horizontal section, of a second embodiment of my present invention;

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 3 and looking in the direction of the arrows; and

FIG. 5 is a horizontal cross-sectional view of a damped spring unit used in the cushioning assembly illustrated in the embodiments of FIGS. 1 and 3.

FIRST EMBODIMENT Referring now to FIGS. 1 and 2, there is illustrated a cushioning assembly generally indicated by the reference numeral 10 and embodying the principles of my invention, which is adapted to be mounted in the end portion (draft gear pocket) of the center sill of a railway car together with a force transfer means. The cushioning assembly 10 is housed in an elongated container 12, which is preferably made as a casting.

The container 12 has an elongated body portion 14 having a pair of generally parallel side walls 18 and upper and lower outwardly

curved walls

20 and 22. A Figure-8 web structure 24 is formed between upper and

lower walls

20 and 22 to define a pair of closed spaced parallel cylindrical passageways 26 extending from closed end wall 28. Integrally formed with the closed end wall 28 is a rectangular flange 30, and a plurality of stiffening ribs 32 extend between the flange 30 and the body portion 14.

A pair of damped spring units 40 are slidably disposed in the cylindrical passageways 26. The damped spring units are identical in construction and comprise an elongated cylindrical casing 42 having an outside diameter slightly less than the diameter of cylindrical passageway 26 and having an internal elongated axial chamber (shown in FIG. 5). As will be described in detail with reference to FIG. 5, a damped spring means is provided in the axial chamber for imposing spring and damping forces between the elongated casing 42 and a piston axially supported in this axial chamber. The piston rod 44 extends through an opening provided in the inner end 46 of the cylindrical casing 42 and has an enlarged end member 48 engageable with end wall 28.

The outer end of the cylindrical casing 42 projects outwardly of the cylindrical passageway 26 and abuts a force transfer member 50, such as for example a standard AAR front follower, to enable the two damped spring units 42 to move conjointly in response to buff forces exerted against the front follower 50 and to move conjointly in response to draft forces transmitted through a strap yoke 51. Thus, it is to be noted that the follower 50 or the strap yoke 51 constitute force transmitting means.

From the foregoing description, it will be appreciated that the novel arrangement of providing the piston rod facing the inner end of the cylindrical passageways 26 and utilizing the cylindrical casings 42 as the guiding surface for the damped spring units prevents eccentric loading on the slim piston rod 44. Thus the piston rod may be loaded close to its yield point in compression without allowing an additional factor for bending.

Another novel feature of this invention is a simple means of pre-s hortening of the draft gear. This preshortening of the draft gear is provided by inserting a light-weight slug 52, of a material such as aluminum, through a preformed opening 54 in the upper wall 20, and positioning of the cylindrical casings 16 so that the slug 52 enters into an annular groove 56, which is cut at the inner end of the cylindrical casings 16, to thereby retain the spring damped unit in the pre-shortened position. Upon impact, the slug 52 will be sheared off and the unit 40 will be free to extend. Likewise a slug is inserted through an opening in lower wall 22 (not shown) and manipulated into an annular groove in the lower damped spring unit.

SECOND EMBODIMENT The second embodiment is depicted in FIGS. 3 and 4 and operates in the same manner as the first embodiment. The difference between the two embodiments is that the second embodiment uses four damped spring units instead of two.

The housing for the second embodiment is shown as a container 60 having an elongated body portion 62 formed by lower and

upper walls

64, 66 and having end walls 68, '70. End wall 68 is solid and closes one end of the container 61) and is secured to upper and

lower walls

64, 66, as by welding. The other end wall 70 is of rectangular shape having four circular openings '71 therein and is likewise secured to the ends of upper and

lower walls

64, 68, as by welding. Disposed lengthwise between upper and

lower walls

64, 68 and aligned with openings 71 in end wall '70 are four cylindrical tubes 74 in a cluster arrangement.

A damped spring unit is slidably mounted within each of the four cylindrical tubes 74. These damped spring units are identical in construction to the two described with reference to the first embodiment and like parts are designated by prime numbers. A front follower 76 abuts the end faces of the four cylindrical casings 42' and a strap yoke (not shown) encompass the container 61) to function as force transmitting means in buff or draft the same as the follower 50 and yoke 51 of HG.

DAMPED SPRING UNlT There is shown in FlG. 5, a damped spring unit, generally designated by the reference numeral 111%, which could be used with the cushioning assemblies of P168. 1 and 3. Although other conventional damped spring units would operate as well as the one shown in FlG. 5, this particular design is preferred because it is relatively inexpensive to manufacture and easy to assemble.

Referring now to FIG. 5, there is indicated generally by the reference numberal 100, a novel damped spring unit enclosed in a cylindrical casing 102. The cylindrical casing 102 has an elongated tubular body portion 104 closed at its ends by forward and

rearward end caps

106 and 108 to define an axial chamber 111 therein. The forward end cap 106 is secured, as by welding, to body portion 104 and has a stepped axial bore 112. including an annular shoulder 114.

A piston 116 and associated piston rod 118 are slidably supported in axial chamber 110 and the forward end portion 120 of piston rod 118 projects through a bushing 121 and snap ring means 122 seated in axial bore 112 of end cap 106. A rod end member 124 is secured concentrically on the forward end face of piston rod 118, for abutting engagement with an end wall such as 28 or 68.

Slidably mounted adjacent to the annular shoulder 114 of end cap 106 is an annular stepped floating sleeve member 126 which carries an O-ring or seal 128 and back-up ring 129 that engage the inner wall of tubular body portion 1&4. interposed between the annular shoulder 114 and the end face 131) of sleeve memher 126 is an annular seal 132 formed of a soft pliable material. A sleeve bushing 134 seats against an annular shoulder 135 at the forward inner peripheral surface of sleeve member 126.

The other end cap 108 is formed of a plurality of interfitting parts which provide a valve means 136 for filling chamber 110 with a compressible solid or elastomer (not shown), such as silicone rubber. A valve receptacle member 138 has a stepped axial bore 140 in which the valve means 136 is mounted and carries an O-ring or seal 142 and leather back-up ring 144 that engages the inner wall of tubular body portion 104. A valve receptacle retainer 146 is threadedly mounted with internal threads formed along the inner wall of tubular body portion 104. A seal 148 having openings 150 formed by radial grooves around its peripheral edge is slidably positioned within axial bore 140 and adjacent to a smaller diameter portion 152 of axial bore 140. A threaded valve seat member 154 having a central opening 158 is threaded into the axial bore 140 and forms a seat against which seal 148 abuts. A threaded plug 156 is threaded into axial bore 140 to positively close the axial bore 140 and prevent leakage of elastorner from the chamber 110. To fill chamber 1 10 with a compressible solid, the plug member 156 is completely unscrewed to expose the passageway formed by the central opening 158, whereupon pressurized injection of elastomer through opening 158 will displace seal 148 from sealing engagement with seat 154 and permit the elastomer to flow through the peripheral grooves 150 of the seal 148, through the smaller diarnetered bore 152 and thence into the chamber 110.

The piston 116 is guided along the cylindrical inner surface 160 of elongated body portion 104 by means of an annular wear ring 162. Piston 116 divides the chamber 110 into two

chamber sections

164 and 166 which are in communication by virtue of a plurality of orifices 168 formed axially through piston 116.

The damped spring units as described with reference to FIG. 5 are designed to be small enough to be adapted to high production parts manufacture. Most parts can be made on automatic screw machines. The tubular body portion 104 could be made for example from honed steel tubing.

1n the operation of damped spring units 160 when assembled into a cushioning apparatus as shown in FIG. 1, impact forces imparted to force transfer means 50 cause casing 1112 to push inwardly of the cushioning container and displace the casing 102 relative to piston 116. During such movement the compressible solid in chamber 164 is forced to flow through axial orifices 168 to chamber 166 to effect a damping and spring force on the movement of casing 102 and thereby provide a dissipation of energy of buff forces applied to the transmitting means 50. At the point of maximum buff travel, the force transmitting means 50 engages the outer end of elongated container 12 and the remaining buff force is transmitted directly through the container 12 to the conventional rear stop lugs (not shown) provided at the rear of the draft gear pocket and in engagement with the rear end wall 28, FIG. 1, or end wall 68 of P16. 3.

When draft forces are imposed on the rear end wall, such as 28, by force transmitting means 51, the container 12 is moved toward front follower 50 which abuts front stop lugs (not shown) and the piston rod 44 is moved inwardly of damping cylinder 42 in the same manner as described above in relation to buff force impacts.

While the compressible solid referred to herein is the preferred compressible medium to be used in the damped spring means of the present invention, it is noted that other compressible mediums such as some of the compressible liquids currently available may be utilized in other embodiments within the scope of the present invention.

From the foregoing, it can be seen that a cushioning device constructed in accordance with the principles of this invention comprises two or more damped spring units mounted in a cluster arrangement within parallel cylindrical passageways provided in an elongated container, which functions as a guide for the individual units and also serves to absorb over-solid blows to protect the units during excessive impacts.

One advantage of the cluster concept is that it greatly reduces production cost by using a multiplicity of smaller damped spring units which are adaptable to high production techniques. Further cost advantages are possible by using standardization of parts since one basic diameter damped spring unit could fulfill all requirements. Piston rod travel requirements are accommodated by varying the length of the cylinder and piston rod. Capacity requirements are met by choosing the proper number of damped spring units.

Another feature of the cluster concept is that the draft gear will still operate if one of the damped spring units becomes inoperative. This concept also lends itself to ease of repair by means of replacing only the inoperative units and returning them to the factory for repair, or the units could be made as throw-away cartridges. If the damped spring units are made as throwaway cartridges, they would be designed with no means for disassembly which would reduce manufacturing cost.

I claim:

1. A cushioning assembly comprising an elongated container having a closed end wall and a plurality of parallel passageways extending lengthwise from said closed end wall, a damped spring unit supported in each of said passageways having an elongated casing of conforming configuration to said passageways slidingly disposed therein, each of said damped spring units including a chamber formed in said elongated casing, a piston and piston rod disposed axially in said chamber with said piston rod having an end portion extending from the inner end of said casing toward said closed end walls, spring damped means in said chamber for imposing spring and damping forces between said elongated casing and said piston in both axial directions, and force transfer means for coupling all of said damped spring units to act conjointly in response to draft and buff forces exerted separately against said force transfer means.

2. A cushioning assembly as defined in claim 1, wherein said plurality of parallel passageways comprises two closely spaced cylindrical passageways and wherein said elongated casing of the two of said damped spring units has a cylindrical shape with a diameter slightly less than that of said cylindrical passageways.

3. A cushioning assembly as defined in claim 1, wherein said plurality of passageways comprises four cylindrical passageways in a cluster arrangement and wherein said elongated casing of the four of said damped spring units has a cylindrical shape with a diameter slightly less than that of said cylindrical passageways.

4. A cushioning assembly as defined in claim 1, wherein said piston has an axial orifice means and said spring damped means comprises a compressible solid filling said chamber for providing a damping and spring force between said elongated casing and said piston.

5. A cushioning assembly asdefined in claim 1, wherein said force transfer means comprises a front follower in engagement with the outer end faces of said elongated casing of said damped spring units.

6. A cushioning assembly as defined in claim 1, wherein said force transfer means comprises a strap yoke encompassing the assembly and in engagement with the rear wall of the elongated container.

7. A cushioning assembly as defined in claim 1, wherein said parallel passageways have cylindrical configurations and said elongated casings have cylindrical configurations of a slightly smaller diameter than that of said passageways, and wherein said parallel passageways are disposed in a close cluster arrangement.

8. A cushioning assembly as defined in claim 1, further comprising pre-shortening means including a breakable slug inserted through a transverse opening provided in said elongated container into one of said parallel passageways and into conforming slot formed in said casing disposed in said one passageway with said damped spring units positioned in a predetermined shortened position.

Claims

5. A cushioning assembly as defined in claim 1, wherein said force transfer means comprises a front follower in engagement with the outer end faces of said elongated casing of said damped spring units.