Note: Descriptions are shown in the official language in which they were submitted.
1078335 :'
SELF LUBRICATING YOKE WEAR PLATE ARRANGEMENT
Thls invention relates to a self lubricating wear
plate arrangement for railroad car draft gear rigging yokes, 7~ r
and more particularly, to a self lubricating wear plate ar-
~rangement for supporting the inner end of the yoke of coupler
draft gear rigging.
Draft gear rigging for, for instance, AAR type F
interlocking couplers conventionally comprises a draft gear
applied within the center sill draft gear pocket, between pairs ~.
of stop lugs fixed to the center sill on either side of same,
.0 which pairs of stop lugs are spaced apart longitudinally of the
I center sill. The draft ger is embraced by a vertical yoke ~:~
¦ extending longitudinally of the car and operably connecte.d to
. the coupler by a vertical connector pin that is supported by
and rides on a support plate secured across the underside of :
the center sill and aiso supporting the outer end of the yoke.
The inner end of the yoke is supported by and rides on a wear
plate that is secured across the underside of the center sill,
and it is upwardly indented to dispose the yoke inner end in
. proper working alignment level with the coupler longitudinally
.0 of the center sill. Additionally and conventionally, a flat
safety plate is secured across the underside of the center sill
between the connector pin support plate and the yoke wear ..
plate, this safety plate normally being disposed below and
spaced from the underside of the yoke.
As the draft gear operates to accommodate buff and
draft impacts acting on the coupler, the yoke slides back and
1078335
forth on its wear plate, which results in wear on both the wear
plate and yoke that is accentuated by a downward acting vector
in the forces acting on the wear plate, due to the location of
the yoke wear plate at the inner end of the yoke. While t~a
yoke wear plates are relatively easy to replace, the yokes
themselves are not because of their embracing relation with the
draft gear. AAR regulations require that when the yoke at its
inner end has worn away about 3/8ths of an inch, the yoke must
be repaired or replaced.
This required repair or replacement of the yoke
necessarily involves shopping of the car for removal of the
draft gear rigging and separation of the yoke from the draft
gear, so that the yoke can be replaced or serviced. The worn
yoke is conventionally restored to working condition by filling
in its worn area with weld material, grinding down the surface
involved to the needed level, and then suitably heat treating ~ -
the yoke to get the repaired area of same to the required
; hardness. After these time consuming procedures, the yoke is
then available for re-use.
The familiar AAR type E coupler draft rigging arrangement
involves the familiar horizontal key connecting the yoke to the
coupler, with the yoke resting on one or more wear plates
secured across the underside of the center sill and either
upwardly indented or built up within the center sill, to dispose
the yoke in proper working alignment level with the coupler,
longitudinally of the center sill. The wearing action on the
yoke in these arrangements presents the same problems referred
to above with regard to yoke and wear plate replacement.
: . .~ ,
`` l07s33s
j;'
A principal object of the present invention is to
¦ .
provide a wear plate arrangement for supporting the yoke, in
¦ .
which metal wear between the yoke and its wear plate is essentially
eliminated, after the yoke surfacing involved has been resurfaced
by polishing to a mirror finish as a result of normal operation .
of the rigging. :
Another principal object of the present invention is
to provide a self lubricating liner arrangement for the yoke
wear plate which is characterized both by dry lubrication and a -
1.0 -re-surfacing of the yoke underside during normal use of the .. .
draft gear rigging that provides the surfacing of the yoke :~ .
which rides on its wear plate, with a wear resisting mirror ;~
like finish.
:~
Still other objects of the invention are to provide a :
yoke wear plate arrangement that avoids the need for a special
''-:
upward indentation in the wear plate or building up of same to
dispose the yoke at its needed operating level, to provide a
liner arrangement for yoke wear plates formed of a material :
characterized by being resistant to adherence of foreign matter
,~, thereto, and to provide a yoke wear plate arrangement of the
type indicated that is economical of manufacture, easy to
install in both new and used equipment, and long lived in .
operation.
In accordance with the present invention, the conventional
yoke wear plate of draft rigging for AAR type interlocking : : .
couplers is replaced by a wear plate assembly comprising a r;
planar support plate that is secured at the same position as a
conventional yoke wear plate, and that is equipped with a ¦ :-
I ` ' . ;
- 3. 1:~
I '
`:
~.
1(~78335 :.
spe~ial liner for supporting the yoke inner end at its operative
level within the car center sill. The liner is formed from an
ultra high molecular weight polymer material that is of dry
self lubricating nature, and resists adherence thereto of
foreign material. The material from which the liner is formed
is also characterized by its tendency to reform the yoke underside
surface portion riding on same whereby such yoke underside
surface portion defines a mirror finish that acts to inhibit
further wear of the yoke during use.
The liner, which may be of either plate or tubular
form, is applied to the planar support plate so that the liner
.material is interposed between the yoke and the new support
plate in question. The new wear plate assembly is equipped to
have the liner centered with respect to the yoke and center
sill.
Other ob~ects, uses, and advantages will be obvious ~ `
or become apparent from a consideration of the following detailed
description and the application drawings in which like reference
numerals are employed to indicate like parts throughout the
several views.
In the drawings:
Figure 1 is a diagrammatic plan view, partially in
section, illustrating a typical mounting arrangement of an AAR
type F interlocking coupler and draft rigging therefor, with
parts being shown in phantom;
Figure 2 is a vertical sectional view through the
draft rigging and associated parts shown in Figure 1, with
parts being shown in phantom and the draft gear being shown in
,, ,, ,,~_,
107B335
block diagram form; :,
Figure 3 is a fragmental view taken substantially '
along line 3--3 of Figure 2, showing one wear plate assembly
arranged in accordance with the invention, with the wear plate :
liner partially broken away, and the center sill shown in '
phantom; ' '
Figure 4 is a plan view of the wear plate asse~bly , .
shown in Figure 3, with the liner shown partially broken away; ~
. Figure 5 is a view similar to that of Figure 4 but . :;
IO illustrating a modified form of wear plate assembly; and
. Figure 6 is a perspective view of still another form .
of wear plate assembly arranged in accordance with the invention. .:
However, it is to be distinctly understood that,the
specific drawing illustrations provided are supplied primarily ;
to comply with the requirements of the Patent Laws, and tha.t
the invention is susceptible of other embodiments that will be
obvious to those skilled in the art, and which are intended to .
be covered by the appended claims. : :
Reference numeral 10 of Figure 1 generally indicates
O an AAR type F interlocking coupler applied to conventional '
center sill 12 that is an integral part of railroad car body 14
~(the latter being largely omitted except for the relevant parts
in the area of the operating location of the coupler 10).
The center sill 12 is of the usual inverted channel .
shape type, defining spaced wide walls 16 and ~ each having
laterally directed end flanges 18 and ~.
The respective center sill side walls 16 and ~ each
:
have applied to same, spaced apart, forward stop lugs ~ and
-, :
5.
':
~078335 1,
rearward stop lugs ~ between which is interposed conventional
draft gear ~ and its associated front follower 22. Draft ¦ . .
gear ~ is shown only diagrammatically as its specifics hav`e
nothing to do with the present invention. :
. The draft gear ~ and its front follower 22 are ~
embraced, as is conventional, by vertical yoke 24 which is ~.
connected to the shank 26 of the coupler 10 by connector pin .
.28 that is supported by support plate 30 that is secured
across the center sill 12, at the level of its undersides 32 ~
0 and 34, by suitable rivets 36. As usual, the spherically -: ;
~on~oured inner end 35 of the coupler seats against the :
correspondingly contoured force transmitting recess 37 of
the front follower 22. : .
. The yoke 24 comprises the usual upper and lower
straps or arms 40 and 42 that are suitably apertured as
indicated in Figure 2 to receive the connector pin 28, and
that are integrally connected together at the inner end 43
of the yoke by the yoke bight portion 44.
The underside 46 of the yoke lower strap 42 is
generally flat or planar in configuration, and at its inner
end 48, it is supported by and rides on the conventional
yoke wear plate that is replaced, in accordance with the
present invention, by the yoke wear plate assembly indicated :
at 50 in the showing of Figures 1 - 4. Conventionally the
draft gear rigging involved also includes a flat safety :
plate 52 secured across the center sill 12 at the level of
its undersides 32 and 34, by employing appropriate rivets
54. As indicated in Figure 2, the safety plate 52 is
:~
6~
1078335
disposed below the normal working level of the yoke lower
strap 42 so as to be out of contact with same.
The conventional yoke wear plate that is not
illustrated is customarily secured across the center plate
in the same manner as plates 30 and 52, and is indented
upwardly so as to dispose the yoke 24 in proper working
level alignment with the coupler longitudinally of the
center sill~(see page 534 of the 1970 Edition of the Car and
Locomotive Cyclopedia).
The wear plate assembly 50 comprises planar, totally
flat, plate 60 that is free of the aforementioned upward
indentation, and that is fixed across the center sill at the
ievel of the center sill undersides 30 and 34, as by employing
suitable rivets 62. Plate 60 has applied to same liner 64
which is of molded or extruded one piece construction and is
formed from an ultra high molecular weight polymer of dry
self lubricating characteristics.
In the preferred embodiment, the polymer is polyethylene
having a molecular weight of at least 2,000,000 and no
greater than about 10,000,000, as the polymer material in
question having a molecular weight much in excess of 10,000,000 -
becomes too difficult to work.
Polyethylene having the ultra high molecular
weight range indicated provides a liner having surfacing that is
; ~ characterized by resistance to adherence thereto of foreign
matter, while being self lubricating in nature and providing a
coefficient of sliding or dynamic friction of the yoke surface
46 on the liner on the order of .02. The material in question,
in addition to being a high strength wear resistinq material
1078335
also is characterized by effecting on the yoke surfaceing
riding on same a polishing or honing resurfacing action such
that after a period of normal use, the yoke surfacing in
question takes on a mirror-like finish whereby the wear
surface of the yoke in question becomes effectively resistant
-
against further wear. Metal worn off the yoke, during the
polishing action in question, seems to embed itself in the
liner wear surface, to the extent it remains in the locale
of the parts involved. Any foreign matter that is caught
between the two surfaces involved also seems to become
embedded in the liner surfacing, and thus is Positioned to
avoid any wearing action on the yoké wear surface involved~ ~-
As indicated, since the material from which the liner is -
made resists adherence thereto of foreign matter, such
foreign matter does not accumulate on the liner and it is
only grit and the like that becomes trapped between the two
surfaces that is subject to the embedding action indicated.
The liner 64 in the form of Figures 1 - 3 comprises
a tubular member 70 formed to define a flat bore 72 that
~0 substantially complements the transverse cross-sectional ;
configuration of the plate 60 for ready application thereto.
Tubular member 70 is proportioned so that its ends 74 and 76
will be closely adjacent if not in contact with the inner
surfaces 17 and 19 of the respective center sill sides 16
:and ~, to maintain the liner ~ centered with respect to
the yoke it is to support.
The tubular member 70 has a wall thickness equivalent
` to that which will support the yoke inner end 43 for proper
~078335 ~,
working alignment with the coupler 10 longitudinally of the center
sili, which dimension is approximately 3/8ths of an inch in prac-
tice. This disposes the yoke and the draf~ gear it embraces in
- horizontal level alignment with the center line of draft (indicated
at 75).
In use, as the coupler 10 is acted on by the usual buff `
and draft impacts, the draft gear 20 functions in the normal manner
to absorb the impacts, which will involve the yoke 24 moving
longitudinally of the center sill inwardly and outwardly of same,
10 'which involves a sliding of the yoke undersurface 48 on the upper
surface 78 of the liner 64. The invention acts to substantially
eliminate the usual mechanical wear experienced on conventional
yoke and wear plate arrangements by the dry self lubricating
L~16~ ~
characteristics of the material forming the ~ 64, and by the
gradual forming on the yoke undersurface 48 of the aforementioned
mirror-like surfacing which tests have shown to have the effect of
making the metal of the yoke resistant to further wear due to rela- ;
tive movement with respect to the liner 64 and its support plate 60.
The wear plate assembly also serves as a sound deadener !,
and impact energy absorber, and thus is particularly useful in the
case of caboose and other cars where noise is a problem. Liner 64
avoids the metal to metal contact of conventional arrangements that
are a source of much noise pollution due to the banging together -~
of the metal parts involved.
In the wear plate assembly 50A of Figure 5, the liner
64A, instead of having the relative length shown in Figure 3,
whereby the length of the member 64 substantially complements
the spacing between the center sill inside surfaces 17 and 19,
the length of the liner 64A is made somewhat in excess of the
maximum width of the yoke lower strap 42. To maintain the
liner member 64A properly centered with respect to the yoke,
lugs 80 are fixed to the plate 60 adjacent either end 74A and
76A of the liner 64A. Liner 64A thus comprises shortened
1078335
.,
tubular member 70A.
Assembly 50A is otherwise the same as that of Figures
1 - 3.
In the embodiment of Figure 6, the assembly 50B
comprises the plate 60 (shown in phantom), which has applied
thereto modified liner 64B that is formed from the same material
as liners 64 and 64A, but is of channel shaped configuration
defining web portion 90 and depending side flanges or ribs 92
and 94 that are spaced apart to receive in a substantially
c~mplementary manner the plate 60. The liner 64A has a length i-
comparable to that of liner 64 whereby the inside surfaces 17
and 19 of the center sill maintain the liner in alignment wlth
the yoke. The flanges 92 and 94, keeping in mind that the yoke
continuously rests on liner 64A, preclude movement of the liner
forwardly and rearwardly of the draft gear pocket.
In this embodiment, if desired the liner 64A may be
fixed to the plate 60 by employing suitable bolts on either -
side of the yoke.
While the wear plate assemblies illustrated are shown
, ?.0 applied to a type F coupler application, they are equally
applicable to type E coupler applications as replacements for
the conventional wear plates therein employed, with like benefits
to the yokes involved. The upward indenting or building up of
the conventional yoke wear plates for type E coupler equipment,
which is similar in amount to that required for type F equipment
is thus avoided by doing the proper positioning of the yoke
with the indicated thickness of the liner.
It will therefore be seen that the invention provides
a wear plate assembly for draft gear rigging yokes which is of
-
10 .
f . .--.... . _ . ,
107~3335 , ~
simplified nature and yet has the capability of eliminating the
wear problem on the yoke and its wear plate that is currently
such a problem to the railroad industry.
The invention is equally applicable to new and old
equipment, and when applied, not only provides for a dry self
lubricating type action, but also a resurfacing of the yoke
undersurface which results in both the yoke and its wear plate
assembly being protected against undue wear. As the material
from which the liner of the invention is made resists adherence
0 thereto of foreign material, the abrasive effect of foreign
matter that is usually found in equipment of this type, especially
where wet type lubricants are employed, will be largely avoided,
with any trapped foreign matter becoming embedded in the liner.
The term "foreign matter" in this regard means the dirt, grit, ~ -
dust, road bed particles and the like that under the car equipment
is exposed to in service, as is well known in the art.
Furthermore, the liner of the invention when the car
~0 is operating absorbs the energy of impacts against it due to
yoke movements relative to it, and in avoiding metal to metal
contact between the yoke and its wear plate, also acts as a
sound deadener.
The foregoing description and the drawings are given
merely to explain and illustrate the 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
the disclosure before them will be able to make modifications
0 and variations therein without departing from the scope of the
invention.
I CL~
11 .
: : :, ,. ., . : , : . .: .;.. . , -
