U.S. patent application number 10/618232 was filed with the patent office on 2005-01-20 for locomotive draft gear assembly and yoke.
Invention is credited to Clark, Marlin E., Fetterolf, John F., Smith, Allen D..
Application Number | 20050011852 10/618232 |
Document ID | / |
Family ID | 34062422 |
Filed Date | 2005-01-20 |
United States Patent
Application |
20050011852 |
Kind Code |
A1 |
Fetterolf, John F. ; et
al. |
January 20, 2005 |
Locomotive draft gear assembly and yoke
Abstract
A yoke for use in a railway locomotive draft gear assembly is
provided. The yoke includes a back wall, a front wall and top and
bottom straps that extend from the front wall to the back wall. The
front wall includes two side sections and a bottom section and a
top section. The top strap and bottom strap are tapered to a
reduced width at the back wall. The draft gear assembly includes
the yoke with a coupler follower adjacent the front wall of the
yoke and a rear follower adjacent the back wall of the yoke. A
resilient member is located between the followers.
Inventors: |
Fetterolf, John F.;
(Mechanicsburg, PA) ; Clark, Marlin E.;
(Collirsville, IL) ; Smith, Allen D.;
(Mechanicsburg, PA) |
Correspondence
Address: |
Edward J. Brosius
44th Floor
205 North Michigan Avenue
Chicago
IL
60601
US
|
Family ID: |
34062422 |
Appl. No.: |
10/618232 |
Filed: |
July 14, 2003 |
Current U.S.
Class: |
213/75R |
Current CPC
Class: |
B61G 7/00 20130101; B61G
9/22 20130101 |
Class at
Publication: |
213/075.00R |
International
Class: |
B61G 001/00 |
Claims
1. A yoke for use in a railway locomotive draft gear assembly, the
yoke comprising: a front wall, a back wall, a top strap extending
from the front wall to the back wall, a bottom strap extending from
the front wall to the back wall, the front wall comprising two side
sections, each side section extending vertically between the top
strap and the bottom strap, the front wall further comprising a
bottom section, a center section and a top section, each of the
bottom, center and the top sections having a convex edge and
extending laterally between the two side sections, the top strap of
reduced width extending from the front wall to the back wall, the
bottom strap of reduced width extending from the front wall to the
back wall, and the back wall includes at least one indented section
of reduced thickness extending from near the top strap to near the
bottom strap.
2. The yoke of claim 1 further comprising, an indented area of
reduced thickness in the top strap and an indented area of reduced
thickness in the bottom strap.
3. The yoke of claim 1, wherein the back wall includes an inside
facing surface forming a bearing area.
4. The yoke of claim 1, wherein the width of the top strap is about
8.25 inches, the width of the bottom strap is about 8.25 inches and
the width of the back wall is about 8.25 inches.
5. A draft gear assembly for use in a railway locomotive coupling
assembly, the draft gear assembly comprising: a yoke comprising: a
front wall, a back wall, a top strap extending from the front wall
to the back wall, a bottom strap extending from the front wall to
the back wall, the front wall comprising two side sections, each
side section extending vertically between the top strap and the
bottom strap, the front wall further comprising a bottom section, a
center section and a top section, each of the bottom, center and
the top sections having a laterally convex shape and extending
laterally between the two side sections, the top strap of reduced
width extending from the front wall to the back wall, the bottom
strap of reduced width extending from the front wall to the back
wall, and the back wall includes at least one indented section of
reduced thickness extending from near the top strap to near the
bottom strap, a front coupler follower positioned between the top
strap and the bottom strap and adjacent an internal surface of the
front wall, a rear coupler follower positioned between the top
strap and the bottom strap and adjacent an internal surface of the
back wall, and a resilient draft gear located between the front and
rear coupler followers.
6. The draft gear assembly of claim 5, wherein the yoke top strap
includes an indented area of reduced thickness, and the yoke bottom
strap includes an indented area of reduced thickness.
7. The draft gear assembly of claim 5, wherein an inside facing
surface of the back wall forms a bearing area.
8. The draft gear assembly of claim 5, wherein the width of the top
strap is about 8.25 inches, the width of the bottom strap is about
8.25 inches and the width of the back wall is about 8.25
inches.
9. The draft gear assembly by claim 5, wherein the front coupler
follower comprises a generally rectangular structure having a top
edge, a bottom edge, two laterally spaced side edges, a front face
and rear face, and each side edge having a side support structure
extending longitudinally from the rear face, each side edge support
structure having a lightener opening therein.
10. The draft gear assembly of claim 5, wherein the front coupler
follower comprises a generally rectangular structure having a top
edge, a bottom edge and two laterally spaced side edges, and a
center support structure extending longitudinally from the rear
face, the center support structure having lightener areas at each
corner.
11. The draft gear assembly of claim 5, wherein the rear coupler
follower comprises a generally rectangular structure having a top
edge, a bottom edge, two laterally spaced side edges, a front face
and a rear face, and each side edge having a side support structure
extending longitudinally from the rear face, each side edge support
structure having a lightener opening therein.
12. The draft gear assembly of claim 5, wherein the rear coupler
follower comprises a generally rectangular structure having a top
edge, a bottom edge and two laterally spaced side edges, and a
center support structure extending longitudinally from the rear
face, the center support structure having Lightener areas at each
corner.
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Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to railcar coupling systems,
and more particularly to draft gear assemblies used in conjunction
with draft sills and couplers in locomotives.
[0002] Draft gear assemblies form the connection between the
couplers at the ends of adjoining railroad freight cars and the
draft sills at the ends of the freight cars. The draft sills are
commonly cast or fabricated sills that are mounted at the ends of
the center sills of the railcar. The draft sills have a pair of
front stops and a pair of rear stops, with a draft gear pocket
between the stops. The draft gear assembly is received in the draft
gear pocket.
[0003] Each draft gear assembly is connected to one coupler, and
couplers of adjacent rail cars are connected to form the train. The
train may be one hundred cars long and drawn by one or more
locomotives. Typically, there is a limited amount of slack or free
movement allowed between the cars; generally there is about two
inches of slack. This slack permits the rail cars limited movement
toward and away from each other in response to train action and
yard impact events.
[0004] Train action events include, for example: locomotive start
up and acceleration; dynamic braking; differences in braking forces
of adjacent cars; and gravity-induced movement of the cars as the
train moves onto and away from inclines. Yard impact events include
"humping" of the individual cars to build the train in the yard; in
humping, a car is pushed over a hump in the track in the yard,
released and allowed to roll down the incline of the hump toward an
awaiting car; during humping, the released cars can reach speeds of
4-10 mph and can severely impact the coupler of the awaiting
car.
[0005] Train action events and yard impact events both subject the
couplers of the cars to buff impacts, and train action events also
subject the couplers of the cars to draft impacts. These impacts
are transmitted from the couplers to the draft gear assemblies to
the rail car body. That is, as the couplers are pulled or pushed,
the movement is translated to the freight car body through the
draft gear assemblies. Typical draft gear assemblies include a yoke
element that is connected to the coupler through a pin or key, a
coupler follower and a draft gear, as well as other elements.
Generally, the coupler follower is positioned against or closely
spaced from the butt end of the coupler in the draft gear pocket,
within the yoke. The draft gear is positioned between the coupler
follower and the rear stops of the draft sill; other elements, such
as a wedge, may be interposed between the draft gear and the
coupler follower.
[0006] In buff events, the butt end of the coupler moves inward
against the coupler follower toward the rear stops of the draft
sill. As the coupler and coupler follower are moved rearward, the
shock of the movement is transferred to the draft gear. The draft
gear typically absorbs and dissipates some of the energy from this
shock through friction.
[0007] In draft events, slack is taken up between adjacent cars
beginning at one end of the train and ending at the other end of
the train. As a result of the slack being progressively taken up,
the speed differences between the railcars increases as the slack
at each coupler pair is taken up, with a resultant increase in buff
and draft impacts on the couplers. This slack is taken up
progressively, coupler pair by coupler pair. When the slack in the
coupler pair joining the last car to the train is taken up the next
to the last car may be moving at a speed of 4 miles per hour. The
slack in the last coupler pair is taken up very rapidly and the
last two cars are subjected to a very large impact capable of
damaging the lading or the car.
[0008] There is an on going review of the weight of freight car and
locomotive components in an effort to maintain strength and
performance, while lessening the weight of such components. One
known yoke for use in a locomotive draft gear assembly is made of
cast steel and weighs about 510 pounds. This shown yoke is made of
Grade B steel.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide our
improved, lighter weight yoke for use in a locomotive draft gear
assembly.
[0010] It is another object of the present invention to provide an
improved, lighter weight locomotive draft gear assembly.
[0011] In one aspect, the present invention provides a draft gear
assembly for use with railway locomotives. The draft gear assembly
has front and back ends and comprises a yoke, a coupler follower,
and at least one resilient member. The yoke has a front wall, a
back wall, a top strap extending from the back wall toward the
front wall. A coupler follower is positioned adjacent the front
wall of the yoke. A resilient member is positioned between the
coupler follower and another follower adjacent the back wall of the
yoke. The top strap and bottom strap of the yoke are tapered to a
reduced width at the back wall. The front wall of the yoke
comprises top and bottom sections of reduced area due to a convex
edge of each section.
[0012] In another aspect, the present invention provides a yoke for
use in a railway locomotive draft gear assembly. The yoke has a
back wall, a front wall, a top strap extending from the front wall
to the back wall, and a bottom strap extending from the front wall
to the back wall. The front wall includes two side sections and a
bottom section and a top section. The top strap and bottom strap
are tapered to a reduced width at the back wall. The front wall top
and bottom sections are of reduced area due to a convex edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Referring to the drawings,
[0014] FIG. 1 is a rear perspective view of a yoke of the present
invention;
[0015] FIG. 2 is a front perspective view of a yoke in accordance
with the present invention;
[0016] FIG. 3 is a top view of a draft gear assembly and coupler in
accordance with the present invention;
[0017] FIG. 4 is a side view of a draft gear assembly and coupler
in accordance with the present invention, and
[0018] FIG. 5 is a perspective view of a follower in accordance
with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring now to FIGS. 1 and 2 of the drawings, a yoke for
use in a locomotive draft gear assembly is shown generally at 10.
Such yoke is typically a single casting of steel. Yoke 10 is seen
to comprise an elongated top strap 12 and an elongated bottom strap
14. Rear end 16 of yoke 10 and front end 18 of yoke 10 are joined
by top strap 12 and bottom strap 14.
[0020] Back wall 16 is shown as having an inner concave surface 17
adapted to abut against the complementary convex surface of the
rear follower.
[0021] Front wall 18 is seen to comprise two side sections 28 that
are spaced laterally and extend from top strap 12 to bottom strap
14. Front wall is further seen to comprise a top section 22, center
section 26, and bottom section 24. Each of front wall top section
22, front wall center section 26 and front wall bottom section 24
are seen to have a convex edge extending from a center forward most
portion back into contact with front wall side sections 28. A draft
pin retainer 20 is seen to extend downwardly from front wall bottom
section 24. By such a design of front wall top section 22, front
wall center section 26 and front wall bottom section 24,
significant weight savings are provided from the prior art
locomotive draft gear yoke, which did not have such convex
edges.
[0022] Bottom strap 14 is seen to include indented section 32 of
reduced thickness in a center area of bottom strap 14. Top strap 12
contains a similar indented area of lessened thickness in an effort
to reduce overall weight of yoke 10.
[0023] Bottom strap 14 is also seen to include a curvature 34
wherein the width of bottom strap 14 is lessened from front wall 18
toward back wall 16. A similar curved section 36 is present on top
strap 12 where by top strap 12 is reduced in diameter from front
wall 18 toward back wall 16. It is also seen that back wall 16 is
of a width similar to the width of the reduced width sections of
top strap 12 and bottom strap 14. Such width is about 8.25 inches.
The reduced width of top strap 12, bottom strap 14 and back wall 16
combine to provide further weight savings in the improved design of
yoke 10.
[0024] Referring now to FIGS. 3 and 4 yoke 10 is shown as part of a
draft gear assembly 50 wherein a coupler 63 is received within
front wall 18 utilizing pivot pin 65. Coupler 63 is comprised of
pivot or butt end 66, shank 64 and coupler head 68. Knuckle 70 is
seen to pivot within coupler head 68. Pivot pin 65 is seen to
extend through openings in front wall top section 22, center
section 26, and bottom section 24. An appropriate bar device
extends through openings in pivot pin retainer 20 to keep pivot pin
65 retained in the coupler draft gear assembly.
[0025] Coupler follower 52 is seen in detail in FIG. 5, and is
usually a cast steel, generally rectangular structure. Coupler
follower 52 includes side edge support 53 that are seen as raised
structure extending from the back wall of coupler follower 52. Side
edge lightener openings 59 are seen to extend through side edge
supports 53 for weight savings. Coupler follower 52 includes center
support 55 which is a raised, generally rectangular section
extending from the back face 51 of coupler follower 52. Such raised
center support adds strength to coupler follower 52. However, for
weight savings, lightener areas 57 are seen to be provided at each
corner of center support 55 for weight savings. Such lightener
areas amount to removal of the corner sections of center support
55.
[0026] Coupler follower 52 is seen to be inserted between top strap
12 and bottom strap 14 of yoke ten and adjacent the inner surface
19 of front wall 18. Rear follower 54 is quite similar to front
follower 52 but is of a bit larger depth. Rear follower 54 is seen
to have a rear face that is positioned adjacent inner surface 17 of
back wall 16. Rear follower 54 is also positioned between top strap
12 and bottom strap 14. Both coupler follower 52 and rear follower
54 are usually comprised of cast steel.
[0027] Draft gear 56 is seen to be positioned between top strap 12
and bottom strap 14 of yoke 10, and is also positioned between rear
wall 72 of coupler follower 52 and rear wall 74 of rear follower
54. Draft gear 56 is seen to comprise a series of plates 58, which
are usually circular in cross section and metallic, usually of
steel composition. Between each plate 58, elastomer pad 60 is
located. As seen from FIGS. 3 and 4, a series of elastomer pads 60
and plates 58 comprise draft gear 56.
[0028] In a buff situation, when lateral force is applied through
coupler shank 64 and pivot end 66 laterally into draft gear
assembly 50, sufficient tolerance is provided in the opening for
pivot pin 65 such that coupler butt end 66 contacts the front face
of coupler follower 52 and imparts a laterally compressive force
against draft gear 56. Draft gear 56 accordingly acts as a
cushioning device to absorb some of the buff load from the coupler.
In draft, when horizontal force is applied through coupler shank
64, such force is applied through pivot pin 65 into front wall 18
of yoke 10.
* * * * *