US3759400A - Housed draft gear - Google Patents

Housed draft gear Download PDF

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Publication number
US3759400A
US3759400A US00237819A US3759400DA US3759400A US 3759400 A US3759400 A US 3759400A US 00237819 A US00237819 A US 00237819A US 3759400D A US3759400D A US 3759400DA US 3759400 A US3759400 A US 3759400A
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United States
Prior art keywords
rubber
housing
friction
draft gear
unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US00237819A
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English (en)
Inventor
G Cope
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Amsted Industries Inc
Original Assignee
Dresser Industries Inc
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Publication date
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Publication of US3759400A publication Critical patent/US3759400A/en
Assigned to FIRST NATIONAL BANK OF CHICAGO, THE reassignment FIRST NATIONAL BANK OF CHICAGO, THE SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: AMSTED INDUSTRIES INCORPORATED
Assigned to AMSTED INDUSTRIES, INC., A CORP. OF DE. reassignment AMSTED INDUSTRIES, INC., A CORP. OF DE. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: DRESSER INDUSTRIES, INC., A CORP OF DE.
Assigned to AMSTED INDUSTRIES INCORPORATED, A CORP. OF DE. reassignment AMSTED INDUSTRIES INCORPORATED, A CORP. OF DE. RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: FIRST NATIONAL BANK OF CHICAGO, AS AGENT
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Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61G—COUPLINGS; DRAUGHT AND BUFFING APPLIANCES
    • B61G9/00—Draw-gear
    • B61G9/04—Draw-gear combined with buffing appliances
    • B61G9/06—Draw-gear combined with buffing appliances with rubber springs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F1/00—Springs
    • F16F1/36—Springs made of rubber or other material having high internal friction, e.g. thermoplastic elastomers
    • F16F1/40—Springs made of rubber or other material having high internal friction, e.g. thermoplastic elastomers consisting of a stack of similar elements separated by non-elastic intermediate layers

Definitions

  • ABSTRACT A housed draft gear for railway vehicles having friction and rubber cushioning units arranged in tandem in an open-fronted cavity of uniform cross section in a houss and 991 e esimbledlslefiev in the s tx, $1.
  • the housing Preferably ported at the sides only for observation of the rubber cushioning unit, the housing had adequate strength at the rear with a rear wall of reduced thickness compared to previous gears, correspondingly increasing the space available for the rubber cushioning unit in the cavity.
  • the preferred friction unit included a central wedge serving as a plunger for the draft gear and friction shoes wedged laterally by the plunger into frictional engagement with the housing.
  • the friction unit was compact and only occupied but a small part of the cavity with both wedge and shoes projecting therefrom for maximizing the space available for the rubber cushioning unit.
  • a releasable interlock between the wedge and the shoes and the shoes and the housing held the several components of the draft gear in assembled relation and permitted their ready assembly and disassembly.
  • the rubber pads or mats are O-shaped with a central tunnel portion. After extensive testing, it was found that this that design provided too little lateral restraint wherein the mat was squeezed out from the spring and spacer plates. Further, the pad has an inability to recover properly after being squeezed out, and the condition became progressively worse, lowering the capacity of the gear to the point where it could not pass the AAR. Z-yearcheclr test as presently called for in Specification M-QOLE.
  • FIG. l is a plan view in working position of a preferred embodiment of the housed draft gear of the pres ent invention, with portions broken away and shown in section to more clearly illustrate certain of the details of construction;
  • FIG. 2 is a side elevational view in working position of the draft gear of FlG. 1, again with portions broken away and shown in section to more clearly illustrate certain of the details of construction;
  • FIG. 3 is a vertical sectional view taken along lines Iii-15 of FIG. 2;
  • FIG. 4 is a side elevational view of the wedge of the friction unit of the draft gear of FIG. 1.
  • each spring unit is characterized by having opposed horizontal and vertical surfaces and a central tunnel portion.
  • a vertical strap member connects the horizontal surfaces and is integral therewith.
  • the strap member substantially bisects the tunnel portion. This provides lateral restraint and recovery means after compression.
  • the opposed vertical surfaces are convex and the opposed horizontal surfaces are concave. This prevents the mats from protruding over the edges of the spring plates under load, thus removing a further hindrance to full recovery of the mat on the removal of the load.
  • each spring consisting of a spring plate sandwiched by a pair of rubber pads ormats are of a thickness greater than and of a cross-section slightly larger than the spring plates.
  • the rear unit 7 is contained longitudinally by and acts between the rear wall 3 and a front spring follower plate 13 separating the rear and front units. While the longitudinal alignment so provided might be adequate, the length of the rear unit, even in the 24 its in. pocket version, is such as to render some intermediate guidance desirable. Accordingly, the rear unit 7 is divided longitudinally by spacer plates 10 interposed between each spring 9 which consists of a spring plate 12 having a rubber pad 11 secured on each side.
  • the spacer plates 10 are thicker than the spring plates 12 to provide both stabilization of the column and protection of the individual spring plates 12.
  • the spring plates 12 are slightly smaller in cross section than the spacer plates so that they are prevented from contacting the sides of the housing and being bent during compression.
  • rubber is used herein to differentiate the rear unit 7 from the front unit 8 and the material of which the pads 11 are made is rubber-like in being elastic and flowing under compression
  • the preferred material is rubber only in that general sense and, in stead of natural or synthetic rubber, is the elastomer known popularly as polyurethane rubber.
  • This preference is dictated in the main by the increased capacity derivable from the higher compression modulus and greater elasticity at high hardness of polyurethane rubber than natural and synthetic rubber and, among polyurethane rubbers, those having a durometer hardness (as measured on the Shore A scale) of around 100 now appear to be the most suitable.
  • the friction cushioning unit 8 upon which the improved draft gear depends mainly for adequate capacity at initial or low travel, has as its preferred components a single center wedge 17, centered transversely on the housing 1, and a plurality and preferably a pair of side wedges or friction shoes 18.
  • the wedge 17 is generally of arrowhead shape in plan and rectangular on any cross section (as shown in FIG. 4) with a forwardly projecting shank 19 at the front and a plural or double wedge, rearwardly tapering head 20 at the rear, the latter having on opposite sides flat, vertically extending, horizontally oblique and rearwardly converging wedging faces 21 on opposite sides of and at equal angles to the longitudinal centerplane of the gear.
  • Both the wedge 17 and friction shoes 18 preferably normally project forwardly from the front end 6 of the cavity 2 beyond the front end 26 of the housing 1 and in the illustrated embodiment the wedge or, more precisely, combined wedge and plunger or wedgeplunger has a flat front face 27 adapted to bear against the rear of a conventional front follower block 28, although, if desired the wedge and block can be integral.
  • the friction cushioning unit 8 divides the applied longitudinal force into lateral and longitudinal components by the wedging action of the wedgeplunger 17 on the friction shoes 18 and uses the lateral component for constantly wedging or urging the outer side or friction surfaces 23 of the shoes into frictional engagement with the sides 25 of the cavity 2 on which they slide longitudinally in the course of the gears travel.
  • the friction unit transmits the longitudinal component of the applied force through the rear bearing surfaces 24 of the shoes and the intervening front spring follower 13 to the rubber cushioning unit 7.
  • the internal friction or hysteresis of the elastomer itself is best kept low because it is then less sensitive to dynamic deformation and, therefore, produces lower reaction levels for a given energy input. In other words, if the rubber has high internal friction it is then more velocity-sensitive and produces higher reaction force levels for a given input at a given velocity.
  • the friction developed by the high spring force levels due to the high compression modulus, is not velocity-sensitive to anywhere near the same degree and, therefore, does not produce inordinately high reaction force levels and this helps to obtain high cushioning capacity at low reaction levels.
  • This minimum aperturing by giving the housing more than usual strength despite its relative simplicity, permits reduction not only in the thickness of the rear wall 3 but also in that of the side walls 4 and 5 by weight-reducing depressions 30 formed in their outsides rearwardly of the portion of the housing at the front which is exposed to lateral forces from the friction cushioning unit 8.
  • the insertibility of the housed parts of the draft gear into the housing 1 through the open front end 6 of the cavity 2 does not stem solely from the uniform cross section of the cavity 2 and, instead, depends in part on the way in which the draft gear is held in assembled relation.
  • the several parts are so held by a releasable interlock pin 31 passing through the upper and lower surfaces of the housing and engages grooves 37 in the wedge-plunger.
  • the wedgeplunger 17 is locked against relative forward movement and also retains the friction shoes 18 against relative forward movement to the housing 1.
  • Each friction shoe 18 preferably has a guide lug 43 extending rearwardly beyond its rear bearing surface 24 as a rearward extension of its outer friction surface i 23 and fitting in an outwardly opening groove 44 in the adjoining side portion of the front spring follower 13 for limiting the relative transverse movement therebetween, as an aid in maintaining the desired longitudinal alignment between the friction and rubber cushioning units.
  • the spacer plates 10, end wall 3 and the internal follower 13 have depressions which correspond in diameter and location to the holes of apertures 14 in the spring plate 12 to provide additional retention and alignment which gives the column some degree of stability.
  • the preferred adaptations of the improved draft gear for 24 as and 36 in. standard pockets will vary in two main respects, one, travel, and the other, the number of rubber springs 9 in their rubber cushioning units 7.
  • the rubber cushioning unit normally will be precompressed or under initial compression to escape the low gradient at the beginning in the compressioncapacity curve of such a unit, and, depending on its length, this precompression does have a definite bearing on its practical furthercompression.
  • the travel of the adaptation of the gear for a 2.4 it pocket ordinarily will be around 3 V4 in. and at that travel tests have indicated the gear to have a capacity of about 51,000 ft. lbs. at 710,000 lbs. reaction, far in excess of the minimum capacity required by the applicable A.A.R. specification. With the greater length of its rubber cushioning unit, the adaptation for the 36 in. pocket would pass by a large margin.
  • a housed draft gear comprising a housing, a cavity in and extending longitudinally of said housing and bounded laterally by side wall means thereof, said cavity being closed at the rear and opening at the front onto a front end of said housing, rubber and friction cushioning units in tandem in said cavity and insertible thereinto through said open front thereof, said rubber unit comprising a plurality of rubber pads having convex opposed vertical surfaces and concave opposed horizontal surfaces being disposed rearwardly and yieldably resisting rearward movement of said friction unit, said friction unit being movable longitudinally in and normally projecting forwardly from said housing and under external longitudinal forces telescoping into and frictionally engaging said side wall means of said housing and compressing said rubber unit, and said cavity being of uniform cross section over at least the area of said'wall means engaged. by said friction unit, and means for normally locking said friction unit and therethrough said rubber unit in said housing.
  • a housed draft gear according to claim 1 in which the rubber units comprise a pair of rubber pads sandwiching an intervening spring plate, each pair being separated by a spacer plate.
  • a housed draft gear according to claim 2 in which the spring plates are slightly smaller in cross section than the spacer plates wherein said rubber unit comprises a plurality of pairs of rubber pads separated by a spring plate, and said rubber pads are characterized by having a central tunnel portion, comprising a vertical strap member connecting the horizontal surfaces and being integral therewith, said strap member substantially bisecting the tunnel portion.
  • a housed draft gear according to claim 1 wherein the means releasably locking the friction unit to the housing is a pin means passing through the housing and engaging a groove in wedge-plunger of the friction unit, in absence whereof the cavity is unrestricted for free insertion and removal of the friction and rubber units.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Architecture (AREA)
  • Vibration Dampers (AREA)
  • Vehicle Body Suspensions (AREA)
  • Gears, Cams (AREA)
US00237819A 1972-03-24 1972-03-24 Housed draft gear Expired - Lifetime US3759400A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US23781972A 1972-03-24 1972-03-24

Publications (1)

Publication Number Publication Date
US3759400A true US3759400A (en) 1973-09-18

Family

ID=22895327

Family Applications (1)

Application Number Title Priority Date Filing Date
US00237819A Expired - Lifetime US3759400A (en) 1972-03-24 1972-03-24 Housed draft gear

Country Status (11)

Country Link
US (1) US3759400A (xx)
AU (1) AU470452B2 (xx)
BE (1) BE796015A (xx)
BR (1) BR7302098D0 (xx)
CA (1) CA973128A (xx)
DE (1) DE2314683A1 (xx)
FR (1) FR2177890B1 (xx)
GB (1) GB1398681A (xx)
IT (1) IT977513B (xx)
NL (1) NL7304012A (xx)
ZA (1) ZA73833B (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120118847A1 (en) * 2010-11-17 2012-05-17 Carlstedt Richard A Railcar draft gear spring assembly and method of making an elastomeric spring unit
US8869954B2 (en) 2011-04-15 2014-10-28 Standard Car Truck Company Lubricating insert for railroad brake head assembly
US8869709B2 (en) 2011-08-10 2014-10-28 Standard Car Truck Company High friction railroad car components with friction modifying inserts

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10250057A1 (de) * 2002-10-26 2004-05-06 Manfred Bartel Zug-Druck-Dämpfungssystem mit Richtgelenkwirkung

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2903143A (en) * 1956-11-23 1959-09-08 Miner Inc W H Shock absorbing mechanism
US2925182A (en) * 1955-11-10 1960-02-16 Symington Wayne Corp Housed draft gear
US3491898A (en) * 1967-09-13 1970-01-27 Dresser Ind Housed draft gear

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2667277A (en) * 1950-04-08 1954-01-26 Miner Inc W H Friction shock absorber for railway draft riggings
BE528605A (xx) * 1953-05-04
US3138264A (en) * 1961-05-22 1964-06-23 Symington Wayne Corp Friction-rubber draft gear
FR1407297A (fr) * 1963-07-22 1965-07-30 Miner Inc W H Dispositif de traction
US3465900A (en) * 1966-08-30 1969-09-09 Symington Wayne Corp Friction-polyurethane rubber draft gear

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2925182A (en) * 1955-11-10 1960-02-16 Symington Wayne Corp Housed draft gear
US2903143A (en) * 1956-11-23 1959-09-08 Miner Inc W H Shock absorbing mechanism
US3491898A (en) * 1967-09-13 1970-01-27 Dresser Ind Housed draft gear

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120118847A1 (en) * 2010-11-17 2012-05-17 Carlstedt Richard A Railcar draft gear spring assembly and method of making an elastomeric spring unit
US8365930B2 (en) * 2010-11-17 2013-02-05 Miner Enterprises, Inc. Railcar draft gear spring assembly and method of making an elastomeric spring unit
US8869954B2 (en) 2011-04-15 2014-10-28 Standard Car Truck Company Lubricating insert for railroad brake head assembly
US8869709B2 (en) 2011-08-10 2014-10-28 Standard Car Truck Company High friction railroad car components with friction modifying inserts

Also Published As

Publication number Publication date
CA973128A (en) 1975-08-19
FR2177890A1 (xx) 1973-11-09
BR7302098D0 (pt) 1974-07-11
BE796015A (fr) 1973-06-18
GB1398681A (en) 1975-06-25
AU5252373A (en) 1974-08-29
AU470452B2 (en) 1976-03-18
DE2314683A1 (de) 1973-10-04
IT977513B (it) 1974-09-20
NL7304012A (xx) 1973-09-26
ZA73833B (en) 1973-11-28
FR2177890B1 (xx) 1977-12-30

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Date Code Title Description
AS Assignment

Owner name: FIRST NATIONAL BANK OF CHICAGO, THE,ILLINOIS

Free format text: SECURITY INTEREST;ASSIGNOR:AMSTED INDUSTRIES INCORPORATED;REEL/FRAME:004666/0778

Effective date: 19860227

Owner name: FIRST NATIONAL BANK OF CHICAGO, THE, ONE FIRST NAT

Free format text: SECURITY INTEREST;ASSIGNOR:AMSTED INDUSTRIES INCORPORATED;REEL/FRAME:004666/0778

Effective date: 19860227

AS Assignment

Owner name: AMSTED INDUSTRIES, INC., 3700 PRUDENTIAL PLAZA, CH

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DRESSER INDUSTRIES, INC., A CORP OF DE.;REEL/FRAME:004513/0932

Effective date: 19850911

AS Assignment

Owner name: AMSTED INDUSTRIES INCORPORATED, A CORP. OF DE., IL

Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:FIRST NATIONAL BANK OF CHICAGO, AS AGENT;REEL/FRAME:005070/0731

Effective date: 19880831