U.S. patent number 3,838,646 [Application Number 05/302,701] was granted by the patent office on 1974-10-01 for noise suppression system for car retarders.
This patent grant is currently assigned to General Signal Corporation. Invention is credited to Willis R. Smith, Daniel E. Turner.
United States Patent |
3,838,646 |
Smith , et al. |
October 1, 1974 |
NOISE SUPPRESSION SYSTEM FOR CAR RETARDERS
Abstract
A noise suppression system for a railway classification yard is
disclosed. An oil-in-water emulsion consisting essentially of one
part of oil and ten parts of water is sprayed against the rail car
wheels as they enter the master retarder. Additional spray means
are provided at the group retarders for spraying additional
emulsion against the wheels of heavily loaded cars as they enter
the group retarders. The oil-in-water emulsion eliminates the
squealing of the car retarders with only a minor reduction in
braking efficiency.
Inventors: |
Smith; Willis R. (Rochester,
NY), Turner; Daniel E. (Rochester, NY) |
Assignee: |
General Signal Corporation
(Rochester, NY)
|
Family
ID: |
23168859 |
Appl.
No.: |
05/302,701 |
Filed: |
November 1, 1972 |
Current U.S.
Class: |
104/26.2;
184/3.2; 188/62; 188/264B |
Current CPC
Class: |
B61B
1/005 (20130101); B61K 3/00 (20130101); B61K
7/02 (20130101) |
Current International
Class: |
B61B
1/00 (20060101); B61K 7/02 (20060101); B61K
7/00 (20060101); B61K 3/00 (20060101); B61b
001/00 () |
Field of
Search: |
;104/26R,26A
;184/2,3R,15B ;188/264B ;356/128,130 ;246/182A |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Conway Yard" by Pennsylvania R.R., date 4/1/58. .
"BN Studies Retarder Noise Abatement" by Burlington Northern in
11/72, issue of "Railway System Controls," pp. 14-17, 20..
|
Primary Examiner: Spar; Robert J.
Assistant Examiner: Oresky; Lawrence J.
Attorney, Agent or Firm: Kleinman; Milton E. Sande; George
Vande Wynn; Harold S.
Claims
I claim:
1. A noise suppression system for car retarders comprising
a. a car retarder for partially braking a rail car, said retarder
comprising a pair of elongated braking shoes mounted on either side
of each rail, said elongate shoes being mounted on a support base
and movable into and out of engagement with the wheels of the rail
car when partial braking is desired,
b. a plurality of spray means mounted on said support base for
spraying an oil-in-water emulsion against said rail car wheels,
said emulsion consisting essentially of lubricating oil and
water,
c. detector means for detecting the presence of a rail car and
energizing said spray means.
2. A noise suppression system for car retarders as claimed in claim
1 wherein said retarder comprises a plurality of elongated braking
shoes on either side of said rail, each of said braking shoes being
provided with a plurality of spray nozzles for spraying said
emulsion against said rail car wheels.
3. A noise suppression system for car retarders as claimed in claim
1 which further comprises a concrete basin which surrounds and
supports said car retarder, said basin providing a collection sump
for the emulsion sprayed by said spray means.
4. A noise suppression system for a rail classification yard, said
system comprising
a. a master car retarder for partially braking a plurality of rail
cars, said master retarder comprising a pair of elongated braking
shoes mounted on either side of each rail, said master retarder
also comprising a detector means for detecting the presence of a
rail car, and weight detector means for determining the weight of a
rail car as it passes through said master retarder,
b. at least one group retarder for partially braking at least one
rail car, said group retarder comprising a pair of elongated
braking shoes mounted on either side of each rail, said group
retarder also comprising detector means for detecting the presence
of a rail car,
c. a plurality of spray means mounted on each of said group
retarders and said master retarder for spraying an oil-in-water
emulsion against the wheels of a rail car, said emulsion consisting
essentially of a lubricating oil and water,
d. control means for actuating said spray means mounted on said
master retarder as said car is passed through the master retarder,
and selectively activating the spray means mounted in said group
retarder when said rail car exceeds a certain predetermined
weight.
5. A noise suppression system for a rail classification yard as
claimed in claim 4 wherein each of said retarders is mounted in a
concrete basin, said basin defining a collection sump for said
emulsion after it has been sprayed against said rail car
wheels.
6. A noise suppression system for a rail classification yard as
claimed in claim 4 which further includes a fluid mixing and
handling system to prepare and supply the oil in water emulsion,
said means comprising a water inlet, an oil inlet, means for mixing
said emulsion, and discharge means for conveying said solution to
said spray means.
7. A noise suppression system for car retarders comprising
a. a car retarder for partially braking a rail car, said retarder
comprising a pair of elongated braking shoes mounted on either side
of each rail, said elongated shoes being mounted on a support base
and movable into and out of engagement with the wheels of a rail
car when said partial braking is desired,
b. a plurality of spray means mounted on said support base for
spraying an oil-in-water emulsion against said rail car wheels,
said emulsion consisting essentially of a lubricating oil and
water,
c. detector means for detecting the presence of a rail car and
energizing said spray means,
d. mixing means for preparing and supplying said oil and water
emulsion, said means comprising a water inlet, an oil inlet, means
for mixing said emulsion, and discharge means for conveying said
solution to said spray means.
8. A noise suppression system for car retarders as claimed in claim
7 which further comprises storage means for receiving the oil in
water emulsion from said mixing means, said storage means having a
liquid level means for withdrawing said emulsion from said mixing
means when the level of emulsion in said storage means has dropped
below a certain predetermined level, said storage means also
defining means for supplying said emulsion to said spray means.
9. A noise suppression system for car retarders as claimed in claim
7 which further comprises a control means for activating said water
inlet and said oil inlet and energizing said mixing means when said
liquid level means indicates the emulsion in said mixing means has
dropped below a predetermined level.
10. A noise suppression system for car retarders as claimed in
claim 8 which further comprises refractometer means for measuring
the relative proportion of oil and water in said mixing means.
11. A fluid mixing and handling system for supplying a lubricating
emulsion to a railway car retarder comprising
a. a car retarder means for braking the wheels of a rail car,
b. spray means mounted on said car retarder for spraying an
oil-in-water emulsion against a rail car wheel, said emulsion
consisting essentially of a lubricating oil and water,
c. mixing means for preparing and supplying an oil and water
emulsion, said mixing means comprising a water inlet, an oil inlet,
means for mixing said emulsion and outlet means for discharging
said emulsion,
d. storage means for receiving the emulsion from said mixing means
and supplying said emulsion to said spray means, said storage means
also having a liquid level means mounted therein for indicating
when the level of said emulsion has dropped below a certain
predetermined level,
e. control means for receiving signals from said liquid level means
and energizing means to withdraw additional emulsion from said
mixing means.
12. A fluid mixing and handling system for supplying a lubricating
emulsion as claimed in claim 11 wherein said mixing means further
includes refractometer means to determine the proportion of oil and
water being mixed in said mixing means.
13. A fluid mixing and handling system for supplying a lubricating
emulsion to a railway car retarder as claimed in claim 12 which
further comprises control valves for said water inlet and said oil
inlet, said control means responsive to said refractometer means to
open and close said oil and water valves to achieve a predetermined
proportion of oil and water in said mixing means.
Description
BACKGROUND OF THE INVENTION
This invention relates to a noise suppression system for use in a
railway classification yard. Specifically, it eliminates the squeal
caused by metal to metal contact when the brake shoes of the master
and group retarders exert a braking action against the wheels of
the incoming railway cars.
Car retarders are employed in railway classification yards in
conjunction with a "hump" over which a string of cars is pushed.
The cars are then individually, or in cuts, allowed to accelerate
down the hump and through the appropriate switching networks to
their ultimate destination. As the cars accelerate down the hump,
it is necessary to keep the speed of travel within certain
predetermined levels in accordance with their rolling resistance,
distance to be travelled before coupling, and various other
factors.
Since light cars generally have the greatest rolling resistance and
thus must be given the greatest acceleration to reach the most
distant destination in the classification yard, the hump is built
high enough to cause light cars to reach sufficient speed to carry
them to the furthest point. Car retarders are then added to reduce
the speed of the heavier cars. The first retarder is employed on
the main track downstream of the hump but before the track divides
into the classification branches. This main retarder is known as
the master car retarder, and the retarders that are placed on the
individual branch lines are known as group retarders.
Each of these retarders employ a pair of elongated brake shoes on
either side of each rail which come together to grip the wheels of
the rail car and cause a partial braking of the car's movement. The
steel-on-steel friction generated by the car retarder at the
substantial loads imposed by the retarder results in a loud and
offensive squeal each time the retarder engages a railway car. The
present invention is particularly adapted to eliminate the squeal
with only a minimal amount of reduction in braking efficiency.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a noise
suppression system which will eliminate the squeal of a railway car
retarder by spraying the wheels of the railway car with an
oil-in-water emulsion as the car passes through the retarder. The
emulsion consists essentially of one part of lubricating oil to ten
parts of water and provides sufficient lubrication to eliminate the
"chatter" or vibration which results in the squealing noise without
substantially impairing the braking efficiency of the car retarder.
In actual practice, the squeal is eliminated with only a 6 percent
reduction in braking efficiency.
A plurality of spray means is mounted immediately adjacent each of
the braking shoes in the master retarder to spray the oil-in-water
emulsion against the wheels of the railway car as it passes through
the master retarder. A car detector means energizes and deenergizes
the spray means for the master retarders. The group retarder spray
means are activated when an exceptionally heavy car is cut through
one of the group retarders. In actual practice, it has been found
advantageous to spray the wheels of each car loaded in excess of 80
tons. Although the group retarders are also used on empty cars and
lighter cars, it has been found that the oil-in-water emulsion
deposited by the master retarder is sufficient lubrication for the
group retarder.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a portion of a railway classification yard
illustrating a master retarder and three group retarders with the
appropriate controls for each;
FIG. 2 is a plan view of a car retarder;
FIG. 3 is an elevation view of a car retarder illustrating the
retarder and a sump formed below the retarder;
FIG. 4 is a detailed plan view of a portion of a car retarder
illustrating the spray means employed in the present invention;
FIG. 5 is a cross-sectional view of a car retarder taken along
section line 5 -- 5 of FIG. 4;
FIG. 6 is a cross-sectional view of a car retarder taken along
section line 6 -- 6 in FIG. 4;
FIG. 7 is a cross-sectional elevation view of the storage means
utilized in the present invention; and
FIG. 8 is a cross-sectional elevation view of the mixing means used
to mix the oil-in-water emulsion in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a plan view of a portion of a rail classification yard.
It illustrates the main track 11 which passes through the master
retarder 12 and then splits into three branch lines 13, 14 and 15.
Each of these branch lines is equipped with a group retarder such
as those illustrated at 16, 17 and 18.
As will be more fully described in FIGS. 2, 3, and 4, each of the
retarders is equipped with a plurality of spray means for spraying
an oil-in-water emulsion against the wheels of a rail car as it
passes through the retarder. The master control for the noise
suppression system is controller 19 which is connected to car
detectors 20 and 21 and which energizes the spray pump 22 for the
master retarder when the car detector 21 senses an incoming freight
car or "cut" of freight cars.
As was pointed out previously, it is intended that every car be
sprayed in the master retarder, but that only those cars in excess
of eighty tons be sprayed in the group retarder. It has been found
the residual lubrication remaining after the spraying operation in
the master retarder is sufficient to prevent excessive noise for
light cars when they pass through the group retarder. It is
desirable, however, to energize the spray means for those
exceptionally heavy cars.
A weight detector 23 is placed on the main track to identify those
cars which are in excess of eighty tons. This is coordinated
through the controller 19, and the controller for the main rail
classification yard to energize the appropriate spray pump control
for the group retarders 16, 17, and 18. These spray pump controls
24, 25 and 26 are also equipped with car detectors to determine the
presence of a rail car at the group retarder. The spray pump
control 24 receives signals not only from the weight detector 23
and the main controller 19, but also from the car detectors 27 and
28. The spray pump control 24 will energize group retarder 16 if
positive or "and" signals are received from both the weight
detector and the controller 19. Similarly, spray pump control 25 is
equipped with car detectors 29 and 30 while spray pump control 26
is equipped with car detectors 31 and 32. The car detectors 28, 30
and 32 deenergize the spray pumps as the car or "cut" of cars pass
through the retarder.
A fluid mixing and handling system is provided to supply an
oil-in-water emulsion consisting essentially of a lubricating oil
and water. The fluid mixing system is indicated generally at 33 in
FIG. 1 and, as will be hereinafter later described with reference
to FIG. 8, includes a fluid handling and mixing means. Conduits 34
and 35 lead to the master retarder and the group retarders and
provide a fresh emulsion consisting essentially of 1 part of
lubricating oil to 10 parts of water. Conduit 34 leads to pump 36
which continually fills a storage means 37. The pump 22 is
energized by a signal from the car detector 21 and draws from the
storage means 37. The emulsion is then sprayed against the wheels
of the rail car as will be hereinafter later described and the
surplus drains into a sump 38 which will be hereinafter later
described. The sump drains through conduit 39 to the group retarder
17. Each of the group retarders 16, 17 and 18 are also equipped
with concrete sump basins to collect the excess emulsion after it
has been sprayed against the railway car wheels. The sump basins
are connected to drain line 40 which returns the used emulsion back
to the mixing and storage means 33. A positive assist is added by
means of pump 41.
The outlet supply conduit 35 leads to the group retarders 16, 17
and 18 and is pumped to intermediate storage tanks 42, 43 and 44 by
means of pumps 45, 46 and 47. The pumps 48, 49 and 50 are energized
by means of spray pump controls 24, 25, and 26 and draw from the
intermediate storage tanks 42, 43 and 44 when the proper
combination of signals has been received by the spray pump
controllers.
The spray means used to spray the oil-in-water emulsion against a
railway car wheels is illustrated in FIGS. 4, 5 and 6. FIG. 4 is a
plan view of one section of a car retarder equipped with a spray
means. FIG. 5 is a cross-sectional view taken along section line
5--5 in FIG. 4. FIG. 6 is a sectional view taken along section line
6-6 in FIG. 4. As will be noted from a brief examination of FIGS. 3
and 4, each of the car retarders is equipped with a plurality of
sections and shoes. One such section or shoe is illustrated in FIG.
4. The car retarder comprises a pair of elongated brake shoes 50
and 51 mounted on either side of a railway car rail. The rails are
supported by means of beams 52 and 53. Each of the beams is adapted
to move the brake shoes 50 and 51 into and out of engagement with a
railway car wheel as illustrated in FIG. 5. The actuating
mechanisms for means 52 and 53 are well-known in the art and will
not be further described. Each of the means 52 and 53 define a load
bearing flange 54 and 55 which extends the entire length of the
beam and provides a mounting surface for the brake shoes 50 and 51.
This flange is reinforced by a plurality of perpendicularly aligned
and equally spaced support ribs 56-62. The ribs are joined together
by means of a web 63 which also extends the length of the support
beam 52. The support beam 53 also defines a plurality of ribs 64-70
and a longitudinally extending web 71.
The spray means comprises a plurality of nozzles mounted on either
side of the rail for spraying the oil-in-water emulsion against the
rail car wheel as illustrated in FIG. 5. In the preferred
embodiment, one-half inch pipes 72 and 73 are mounted on either
side of the rail by means of a plurality of spring clips 74 and 75
which extend over the pipe 73 and down through an opening 76
defined in the webs of the beams 52 and 53 to clamp said pipes
against said beams. The pipe itself rests upon the upstanding ribs
56-62 of beam 52. The resilient nature of clamps 74 and 75 ensures
that the pipes 72 and 73 are held securely in place.
Each of the pipes 72 and 73 is equipped with a plurality of spray
nozzles. These spray nozzles 77-83 for pipe 72 and nozzles 84-90
for pipe 73 are aligned to provide a continuous bath of
oil-in-water emulsion on either side of the rail 91. The diverging
nature of the sprays, and the curved portions 72a and 73a provide
angled sprays which will thoroughly wet both the flange 92 and the
rim 93 of the rail car wheel. The curved portions 72a and 73a also
ensure the space between the individual retarder sections is
covered. Since the brake shoes are brought to bear against the rim
on one side and the flange on the other, it is necessary that both
surfaces receive the proper amount of lubrication. The 1:10 ratio
or mixture of oil and water has been found to provide the proper
degree or amount of lubrication when the rail car wheels are
thoroughly wetted with the emulsion.
FIGS. 2 and 3 are diagrammatic views of the complete retarder with
some of the detail omitted for purposes of clarity. FIG. 2
illustrates a plurality of elongated braking shoes 101-120 mounted
on either side of each rail 121 and 122. Each of these braking
shoes is supported by the respective support or retarder beam
101a-120a. The beams in turn support spray pipes 121-140 which are
secured to the beams in the manner illustrated in FIGS. 5 and 6.
The pipes are connected together by means of rubber hose connectors
121a-140a. These connector hoses provide the requisite flexibility
for the spray pipes since each section is individually operated.
They also provide for the relative expansion between the various
members due to extreme temperature variation. The spray pipes
121-140 are connected to the fluid supply system by means of
manifold 141 which extends perpendicularly to the tracks 121 and
122 and intersects the spray pipes 121-140 at a convenient
midpoint. The midpoint is selected to minimize the problems
associated with pressure drop across the respective lengths of
piping 121-140. Each of the terminal ends of spray pipes 121-124
and 137-140 is equipped with caps to seal the ends of the spray
pipes and to prevent the discharge of emulsion therefrom.
The retarder illustrated in FIG. 2 is illustrated in elevation view
in FIG. 3. As indicated previously, the retarders are generally
placed on the slant of a "hump" to assist in regulating the speed
of a railway car after it passes over the hump and is routed to its
preselected destination. The individual retarder beams 104a-120a
are supported by a plurality of wooden railway cross ties 142-150.
These cross ties are in turn supported by a concrete basin or sump
illustrated generally by numeral 151. This sump provides a
collection point for the excess emulsion sprayed against the car
wheels as they pass through the retarder. As was previously
described in FIG. 1, the emulsion 152 collected in the lower
portion of the sump is routed back to the mixing and storage means
33 by means of drain pipes 39 and 40 and pump 41.
The fluid mixing and handling system for supplying the oil-in-water
emulsion is illustrated in FIGS. 7 and 8. FIG. 7 is a
cross-sectional and elevation view of the storage tank provided at
each of the retarders. FIG. 8 is a cross-sectional and elevational
view of the mixing means for preparing the oil-in-water
emulsion.
As illustrated in FIG. 8, the mixing means comprises a water inlet
201, an oil inlet 202, and a discharge outlet 203 for discharging
the oil-in-water emulsion. The tank 204 is sized to accomodate the
total volume of all the retarder storage tanks. The incoming
solution from conduit 40 is first filtered by filter means 205 and
then pumped by means of pump 206 into the mixing tank 204. This
pump is actuated whenever the liquid level in the mixing tank drops
below a certain predetermined level. This predetermined level is
established by the position or placement of the detector 207
mounted in the wall of the mixing tank 204. When pump 206 is
activated, it drains the emulsion from each of the retarder sumps
and recycles the filtered emulsion for reuse in the system. In the
preferred embodiment, a large percentage of the solution is
recovered and recycled for reuse in the system. In the event there
is no solution available in the retarder sumps to fill the mixing
tank 204, the mixing controller 208 will open the water control
valve 209 and allow a predetermined quantity of water to be
admitted to the mixing tank 204.
A second detector 210 is placed within the mixing tank 204 to
determine the level where the maximum addition of soluble oil will
fill the tank if the solution is pure water. When detector 210 has
indicated that the requisite amount of water has been supplied to
the mixing tank 204, it will close valve 209 and energize the
refractometer 211 to analyze the solution 212 in the mixing tank
204. At the same time, the mixing means 213 will be energized by
drive means 214 to thoroughly mix the existing emulsion with the
incoming water. After a suitable time delay, the refractometer will
analyze the percentage of oil and water and provide a
representational signal to the master controller 208. The master
controller 208 will then open the lubricant control valve 215 to
allow the proper amount of oil to enter the mixing tank 204.
Detector 216 senses the maximum quantity of emulsion desired in the
mixing tank 204. It also operates as a high limit or upper limit
control in the event of failure of one of the other components.
The automatic analysis of the emulsion 212 is also necessary since
substantial amounts of rain water will be collected in the sump
basins 151 and the mixture pumped from the retarder sumps may have
a vastly altered oil to water mixture ratio. In the event a
substantial amount of fresh water has been added to the system,
pump 206 will fill the mixing tank to the level indicated by
detector 210. At that time, the mixture will be analyzed by
refractometer 211 and if additional oil is needed to bring the
mixture to the proper ratio, valve 215 will be open, and the
appropriate amount of oil will be added to the solution. Although
the emulsion is extremely stable, it may be desirable to have the
mixing means 213 continuously rotating within the tank 204. This
would ensure that the lubricant and oil do not separate. The
solution is drawn from the mixing tank 204 to each of the retarder
storage tanks by means of pumps 36, 45, 46 and 47. The storage tank
for retarder 12 is illustrated in FIG. 7 wherein pump 36 draws the
mixture from the mixing tank to the storage tank 37. A pair of
liquid level indicators 217 and 218 provide low level and upper
level limit indicators for the amount of solution stored in tank
37. When the amount of solution has dropped below the level
predetermined by level indicator 217, the control means 219
energizes pump 36 and withdraws the appropriate amount of solution
from tank 204 to fill the local storage tank 37. When the level of
the solution reaches the level indicated by level indicator 218,
pump 36 is deenergized. The solution is withdrawn from storage tank
37 through conduit 220 by means of pump 22. Pump 22 is activated by
controller 19 whenever the car detector 21 senses a railway car
entering the master retarder. After the car has left the retarder,
pump 22 is deenergized by the car detector 20.
The emulsion provided by the fluid mixing and handling system is an
oil-in-water solution consisting essentially of a lubricating oil
and water. It has been found that a mixture of Texaco type 1609,
class 38 soluble heavy duty oil, mixed ten parts of water to one
part of oil will eliminate the noise and squeal of the normal car
retarder but will only reduce the braking efficiency by
approximately 6 percent.
In a first test of the retarder noise suppression system, a mixture
of 20 parts of water to 1 part of soluble oil was used with only
partial abatement of the noise. Of ten cars that passed through the
retarder, two generated substantial noise when the retarders were
actuated.
In a second test of the solution, that being 10 parts of water for
1 part of oil, all the cars passed through the retarder without any
excessive noise or squealing and the effective retardation was
diminished by only 6 percent.
In a third test, a mixture of 5 parts of water to 1 part of oil was
employed and the noise was totally eliminated; however, the
retarder efficiency was substantially reduced.
The mixture of oil and water appears thoroughly emulsified. The
Texaco 1609 class 38 soluble heavy duty oil is reddish in
appearance, but when mixed with 10 parts of water to 1 part of oil
provides a milky, almost opaque solution.
While there has been described what at present is considered to be
the preferred embodiment of the present invention, it would be
obvious to those skilled in the art that various changes and
modifications may be made therein without departing from the
invention. For example, it would be possible to interchange the
liquid level detectors 207, 210, 216, 217 and 218 with continuous
line level indicators to provide an analog output. Additionally,
the refractometer 211 could continuously analyze the solution 212
to continuously adjust the oil and water mixture present in the
mixing tank 204.
Having thus described a noise suppression system in one specific
embodiment, it is understood that this form is selected to
facilitate the disclosure of the invention rather than to limit the
number of forms which it may assume. It is further understood that
various modifications, adaptations, and alterations may be applied
to the specific form shown to meet the requirements of practice,
without in any manner departing from the sphere of scope of the
following appended claims.
* * * * *