Note: Descriptions are shown in the official language in which they were submitted.
CA 02434590 2004-08-17
-1-
A PARKING BRAKE FOR A RAIL VEHICLE
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to parking brakes for rail vehicles
and more
specifically to a parking brake with an actuator, and a force multiplier that
is connected to
a brake cylinder piston which applies and releases the brakes on a rail car.
The prior art discloses a number of parking brake systems for rail vehicles.
Some
of the parking brake systems operate independently of the overall brake system
for the
train and others are integrated with the overall brake system, particularly by
using the
main brake cylinder that operates the train's brakes.
In general, brake systems for rail vehicles are pneumatically (air) operated.
The
brake system includes a brake cylinder with a piston rod to operate the brake
shoes to
engage the rail car wheels and brake the rail car. The brake cylinder receives
a signal to
apply the brakes and generally has a spring return to release them. The signal
or force to
activate the brakes is generally multiplied by some sort of lever that is
located between a
brake cylinder actuator and the brake shoes. Other brake cylinders may be
spring applied
and air released.
Most rail cars have a manually-operated parking brake that applies the wheel
brakes. Generally, for truck-mounted brake systems, which are well-known in
the art, one
end of the brake cylinder has a piston rod output that is connected to levers
or similar
elements which connect the brake cylinder to the brake beams. Furthermore, as
part of the
parking brake system, a combination of chains and cables are generally used to
connect
the brake cylinder to a manually-operated actuating device. That connection
often includes
a multiplier lever. The multiplier lever is connected to a convenient location
on the rail
car.
The prior art also discloses an electropneumatic controlled parking brake,
that is
one that has electrical and pneumatic elements.
Manual fluid pumps to actuate separate hydraulic parking brakes on railroad
vehicles are also disclosed in the prior art. Those parking brakes are
connected to the
brake beams and may or may not be independent of the main brake cylinder.
Some rail car users or operators may prefer to eliminate the use of cables to
connect the brake cylinder to a multiplier lever because of brake system
complexity and
CA 02434590 2004-08-17
-2-
cost, or for other reasons. Users may also like to have additional options as
to where the
multiplier levers could be located or positioned as part of any parking brake
system. The
present invention addresses those concerns and interests.
According to an aspect of the present invention there is provided is a parking
brake
for a rail vehicle having a brake cylinder and a piston in the brake cylinder
responsive to
forces to apply and release the brakes on the vehicle. The brake cylinder may
have a
pressure side and a non-pressure side. The parking brake further includes at
least one off
center connecting rod extending though an opening in the brake cylinder and
connected to
or with the piston through that opening. The opening may be on the pressure or
non-
pressure side of the brake cylinder. The at least one off center connecting
rod may
function as an anti-rotational rod. The parking brake also includes a force
multiplier
connected to or with the at least one rod. Further included is an actuator
connected to or
with the force multiplier for driving the force multiplier to provide the
force to move the at
least one rod and the piston to move the brakes to an apply position.
According to an aspect of the present invention, there is provided a parking
brake
for a rail vehicle comprising: a brake cylinder and a piston in the brake
cylinder responsive
to forces to apply and release brakes on the vehicle; at least one off center
connecting rod
extending through an opening in the non-pressure side of the brake cylinder
and connected
to the piston through the opening, a force multiplier; a non-flexible
connector directly
connecting the force multiplier to the at least one off center connecting rod;
and, an
actuator connected to the force multiplier for driving the force multiplier to
provide the
force through the non-flexible connector to move the at least one off center
connecting rod
and the piston to move the brakes to an apply position.
According to an aspect of the present invention, there is provided a parking
brake
for a rail vehicle comprising: a brake cylinder and a piston in the brake
cylinder
responsive to forces to apply and release brakes on the vehicle; at least one
off center
connecting rod extending through an opening in the brake cylinder and
connected to the
piston through the opening; a force multiplier supported by the brake cylinder
and
connected to the at least one off center connecting rod; and an actuator
connected to the
force multiplier for driving the force multiplier to provide the force to move
the at least
one off center connecting rod and the piston to move the brakes to an apply
position.
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In this application, an element may be connected to or with another element,
meaning that the connection may be direct or indirect regardless of whether
the word
CA 02434590 2003-07-08
_3_
"to" or "with" is used to describe the connection. Either "to" or "with" may
be used
herein, and they are interchangeable.
Other featuxes of the pxesent invention will become; apparent from the
following detailed description of the invention when considered in
conj~~~ctio~~a with.
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRA~T1NCS
Figure 1 is a perspective view of a prior art truck-maunted parking brake
mounted on a rail cax.
Figure 2 is an exploded perspective view of a priox art parking brake systean
having a multiplier connected to bxake cables that are connected to a brake
cylinder.
Figure 3 is a perspective, schematic view of a parking brake acco~dbng to the
principles of the present invention.
Figure 4 is a perspective view of a first embodiment of a parking brake
according to the principles of the present inventim.
Figure 4A is an exploded view of the parking brake of Figure 4.
Figure 5 is a perspective view of a second embodiment of a parking brake
according to the principles of the present invention.
Figure SA is an exploded view of the parking brake of Figure 5.
Figuxe 6 is a perspective view of a third embodiment ~of a parking brake
according to the principles of the present invention.
Figure &A is an exploded view of the parking brake of Fig~zre G.
Figure 7 is a perspective view of a fourth embodiment of a parking brake
according to the principles of the present invention.
Figure 7A is an exploded view of the parking brake of Figure 7.
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Figure 8 is a perspective view of a fifth embodiment of a parking brake
according to the principles of the present invention.
Figure 8A is an exploded view of the parking brake of I' figure 8.
Figure 9 is a perspective view of a sixth esn.bodinxent of a parking brake
according to the principles of the present invention.
Figure 9A is an exploded view of the parking brake of Figure ~.
Figure 9B is a cross-sectional view of the mounting c~f a carry to a brake
cylinder according to the principles of the invention:.
Figure 10 is a perspective view of a seventh eanbodirnen.t of a parking brake
according to the principles of the present invention.
Figure 10A is an exploded view of the parking brake of Figure 10.
Figure 11 is a perspective view of an eighth e~nbodirnent of a parking brake
according to the principles of the present invention.
Figure 11A is an exploded view of the parking brake of Figure 1 l .
1 S Figure 12 is a perspective view of a ninth embodianent of a parking brake
according to the principles of the present invention.
Figure 12A is an exploded view of the parking brake ofFig;aare 1?.
Figure 13 is a perspective view of a parking brake system installed on a rail
car according to the principles of the present invention.
DETAILED DESCRIPTIt7N OF THE PREFER1~ED EMB~DIMENT~
Parking brakes on rail vehicles are well known in the art. ~eneraliy, as shown
in the prior art of Figure l, a parking brake or hand brake system includes an
actuator,
such as a hand wheel 43 and chain 40 as well as a force multiplier 30 z~ounted
to tgie
end of a rail car 44. The actuator chain 40 can be connected to a brake
cylinder 22.,
for instance, through a series of handles and transfer levers (not
id.°ntified for sake of
CA 02434590 2003-07-08
clarity). Applying a force to the actuator chain 40, far example, by turning
the
wheel 43, pulls the chain 40 and ultimately transfers the pulling f~rce to the
brake
cylinder 22 which applies the brakes to the rail car's wheels.
Figure 2 illustrates a prior art mechanical parking or hand brake 20 wherein a
pair of hand brake cables 42 are connected on one ez~d to a piston {not shown)
tl~~ough
openings 28 in the brake cylinder 22. ~n the other end, the cables are
connected to
force multiplier 30 and actuator chain 40. Actuator chain 40 can be connected
to an
actuator wheel 43 mounted on a rail car, as shown in Figure 1.
The parking brake of the present invention is shown in Figures 3-13.
Figure 3 shows a parking brake 20 for a :rail vehicle that ir~civdes a brake
cylinder 22 and a piston {not shown) inside the brake cylinder fleet is
responsive to
forces to apply and release brakes on the vehicle via piston rod 24, which
rides inside
piston rod sleeve 25. The parking brake 20 also includes at least one off
center
connecting rod 26, that extends through at least one opening28 izF the a brake
cylinder 22. The at least one off center connecting rod26 is con:rzected to
the piston
(not shown) through the at least one opening 28.. The parking brake 20
fo:frther
includes a force multiplier 30 (shown schematically) that is connewted to or
suppoz-ted
by the brake cylinder 22 and connected to the at least one ofd center
connecting
rod 26. Also included in parking brake 20 is an actuator 40 (shown
schematically)
connected to the force multiplier 30. The actuator 40 may also be. connected
directly
to or located within brake cylinder 22. The actuator40 provides the force to
move the
at least one off center connecting rod 26 via multiplier 30 and the piston
(not shown)
to move the brakes to an applied position.
The brake cylinder piston is not shown in any of the embodiment figures and,
when referred to, will hereafter be referred as the piston without identifying
the piston
CA 02434590 2003-07-08
with a numerical designation. The piston is connected to a piston rod24 that
extends
from the brake cylinder 22 and the rod 24 may be exzclosed in a piston rod
sleeve 25.
A flange 68 is generally included and used to mate the non-pressure side 27
and a
pressure side 29 (as shown in Figure 3) of the brake cylinder 22.
tsenerally, the parking brake of the present invention, as shown in Figure 3,
works as follows. The actuator40 applies a force to the force multiplier 30
that is
connected to or supported by the brake cylinder 22. The force multiplier 30
mop=es
the at least one off center connecting rod26. The at least one off center
connecting
rod 26, being connected to a piston (not sho'vn) in the brake cylinder22,
drives the
piston rod 24 which moves the brakes (not shown) to an applied position on the
vehicle's wheels (not shown).
Figures 3-13 show the preferred embodiments of the parking brake of the
present invention.
It should be noted that except for the numerical designation of tl~e parking
brake (e.g., 120 for the first embodiment (Figures 4 and 4A); '220 for the
second
embodiment (Figures 5 and 5A), etc.) certain elements designated anal.
described in
the first embodiment are also included in other embodiments of this invention.
Those
elements are commonly numbered and their function in each of the other
embodiments is essentially identical to that described in the first embodiment
except
where noted otherwise in each embodiment. Those elements include ba~ake
cylinder 22, piston rod 24, piston rod sleeve 25, off center connecting rod26,
non-
pressuxe side 27, opening 28, pressure side 29 and flange 6$. Every though all
of these
elements and their function are included in each of the embodiments (Figures 4-
12A),
their description and function will not necessarily be repeatef. in each of
tlae
succeeding embodiments. Also, generally, elements with the identical last two
CA 02434590 2003-07-08
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numerical digits have similar functions and their number increa;~es by adding
at least
I00 to those last two digits in each succeeding embodiment (e.g.,pin 166 in
the first
embodiment (Figures 4 and 4A) essentially performs the same ffi~~-~etion as
pin 1266 in
the ninth embodiment (Figures 12 and 12A), but may perform tlxat function or
be used
on or between different elements).
FIRST EM~013IIVgEa~IT
A first embodiment, shown in Figures 4 and 4A, is parking brake 120 that
includes the brake cylinder 22 with a piston (not shown) inside the brake
cylinder 22.
The parking brake 120 also includes at least one off center connecting rod26
that extends though an opening 28 in the non-pressure side 27 of the brake
cylinder22
and is connected to the piston through the opening 28. ~Ihile Figures ~ and 4A
show
or indicate that there are two off-center connecting rods 26, one vrith
ordinary skill in
the art would know how to make the present invention with one off center
connecting
rod 26 or with more than two off center connecting rods 26.
Also, the off center connecting xod(s) 26, as shown in Figures 3-13, may be
located or positioned at other places on the non-pressure side 27 of the brake
cylinder
22. For example, the off center connecting rods 26 spawn in Figures 6 and 6A
have
been rotated 90° from their position shown in Figures 4 and 4A.
Parking brake 120 also includes a force multiplier 130 shown as a bifurcated
closed fork or a Y-shaped lever in Figures 4 and 4A. ~tlaer shapes of force
multipliers or levers are contemplated. The force multiplier 1~0 is supported
by the
brake cylinder 22 by non-flexible linkage 160. The linkage I60 is connected to
a boss
or mounting plate 165, which is connected to flange 68. Linkage I60 may
include
links 180 and pins 178. Force multiplier 130 may also be pivotally connected
to the
at least one connector rod 26 by assembly 150, which may include clevis or
clevi~
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~_8_
like element 162 and pin 166. Clevis 162 may be mounted on, or be a part of,
the end
of the off center connecting rod 26. Parking brake 120 also inclrades an
actuator 140,
shown as a chain. Chain 140 may be connected to force multiplier 130 at
connection
point 141.
Force multiplier 130 includes a lever connected to actuator 140 at a first
position 141 on the lever 130 and is connected to the at least one off center
connecting rod 26 at a second position, pin 166, on the lever 130 and is
supported by
the brake cylinder 22 at a third position, pin 178, on the lever 130. It is
possible, in
this and other embodiments, that the second position may be between the first
and
third positions on the lever (as is the case in this embodiment), or the thi~d
position
may be between the first and second positions on the lever (as in the third
embodiment, shown as Figures 6 and 6A).
When a force is applied to actuator or chain 140, force ~miltiplier 130 is
pulled
in direction 100. Multiplier 130 pivots about the substantially nixed pi~o~
point or
axis 132, which is defined by pin 178 that connects link 180 to force
rxmltiplier 130.
The pivot axis 132 is located below off center connecting rod 26 as vie~reci
from the
top of force multiplier 130 at connection point 141. Stated another way, the
connection, at pin 166, of the multiplier 130 to the off center connecting rod
26 is
between the connection, at point 141, of the multiplier 130 to the actuator
140 and the
connection, at pin 178, connecting the brake cylinder 22 to the force
multiplier 130.
As multiplier 130 is pulled to the left (as showrn in Figures 4 and 4A),
connector rod 26 is pulled to the left as well. Off center connecting rod 26,
being
connected to the piston inside brake cylinder22, drives piston rod 24, which
rides
inside piston rod sleeve 25. Sleeve 2S fts inside brake cylinder extension
184.
Cylinder extension 184 may be connected integrally to or cast monolithically
with
CA 02434590 2003-07-08
,
brake cylinder 22. Piston rod 24 in turn moves the brakes knot shovan~ to an
apply
position on the rail vehicle's wheels.
Force multiplier 130, as do the force multipliers in the other embodiments
herein, performs at least two functions. First, it multiplies the force that
is applied at
connection point 141 through actuator 140, and applies that multiplied force
to
connector rod 26 through connector assembly 150. Second, multiplier 130
inversely
multiplies the distance traveled by chain 140 and causes connector rod 26 to
move a
distance that is inversely proportional to the distance traveled by chains
140.
Generally, the "multiplier ratios" for the force and distance mult2piiers of
the present
invention range generally from approximately 1:l to 4:1 for the :force
multiplier and
1:1 to 1:4 for the distance multiplier. Tllat is, for example, for an
approximately three
inch movement of the chain 140 there will be approximately a one inch movement
of
the off center connecting rod 26. For the force component, if approximately
3,000
lbs. of pull force is applied at connection point 141, there will be
approximately 9,000
lbs. of pull force applied to off center connecting rod 26. For the present
irwention's
best mode of operation, the force ratio is expected to be ~pprox~:mately 3:1
and the
distance ratio is expected to be 1:3. Other ratios are also contemplated.
SECOND EMBODIMENT
A second embodiment, shown in Figures 5 and SA is parking brake 220. The
force multiplier 230 is a bifurcated U-shaped lever which ~~.ay include
legs434.
Force multiplier 230 is supported by, and may be pivotally connected to, the
brake
cylinder 22 through assembly 250. Assembly 250 may include a collar286 that
its
around piston rod sleeve 25 and may have a boss282 with a hole''<Y88 for
connection
to a cylinder extension boss 28~ on cylinder extension 284. Assembly 250 may
also
CA 02434590 2003-07-08
° 10-
include pin 292 and nut 294 extending through holes in boss 2E7. dollar 286
rnay
also be connected integrally to, or cast monolithically witlA, brake cylinder
22.
Force multiplier 230 is connected to the at least one ofd center connecting
rod 26 by linkage 260, which may include two links 280 and two connector
pins27~
for each rod 26. Linkage 260 may connect to rod 26 thro~~gh opening 25~,.
Parking brake 220 also includes an actuator 240, show's as a chain, which may
be connected to the force multiplier 230 at connection point 241 on Handle 239
of
force multiplier 230.
Thus, the force multiplier 230 includes a lever connected to actuator 240 at a
first position 241 on the lever 230 and is connecWd to the at least one ofd
center
connecting rod 26 at a second position, pin 278, on the lever 230 and is
supported by
the brake cylinder 22 at a third position, pin 292, on the lever.
When a force is applied to actuator or chain 240, force multiplier 230 is
pulled
in direction 200. Force multiplier 230 pivots about the substantially fixed
rotational
axis 232, which may be defined generally by the longitudinal axis of pirz292.
As in
Figure 4, pivot axis 232 is located below off center connecting rod 26 as
viewed from
the top of force multiplier 230 at connection point 241. Stated another way,
tl~e
connection, at pin 278, of the multiplier 230 to the off center connecting rod
26 is
between the connection of the force multiplier 230, at point 24I, to the acW
ator 240
and the connection, at pin 292, connecting the brake cylinder 22 to the force
multiplier 230.
As force multiplier 230 is pulled to the left in direction 200 has shorn in
Figures 5 and SA), off center connecting rod 2G is pulled to the left as well,
and the
brakes are moved to an apply position as described in the first embodiment.
CA 02434590 2003-07-08
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This embodiment also includes a sheave wheel 270 that may change the pull
direction 200 to pull direction 200A. Pull direction 200A differs by
approximately
90° from pull direction 200. Sheave wheel 270 may be rraounteax on the
rail car, tlae
rail car truck or other appropriate location.
A change in the direction of pull may be dictated by where, for instance, an
actuator wheel 43 or equivalent device (see Figure 1) is located and where and
how
the brake cylinder 22 is mounted on the rail car trdaclc. A she;ave wlxed,
sucks as
sheave wheel 270, may thus be used to change direction of pull from a "end of
car"
actuator wheel mounting location (such as shown in Figure 1 ) to a "side of
car"
location (not shown) or vice versa. If desired, more than one s:~eave wheel
can be
used. In addition, one or more sheave wheels may be used with all of the
present
embodiments.
THIRD EMB~DIMEIVrT
A third embodiment, shown in Figures 6 and 6A, is parking brake320. the
force multiplier 330 is a single-handle, Y-shaped lever, which may include
legs 334
and handle 339. The legs 334 may be a single unit and curved, as shown in
Figures 6
and 6A, or the legs may be shaped in a different con~rgurstio~a,. T'he handle
339 rxay
include one or more pieces. The handle 339 and legs 334 may be integrally
connected, for instance, by welding or cast as a monolithic unit. Also, force
multiplier 330 may be a bifurcated fork lever similax to force multiplier 130,
as shown
in Figures 4 and 4A.
Force multiplier 330 is supported by brake cylinder 22 by linkage 360.
Linkage 360 is connected to a boss or mounting plate 365, which is connected
to
flange 68. Linkage 360 may include links 380 and pins 378. Force multiplier
330
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-I 2-
may also be pivotally connected to the at least one off center connector rod
26 by
assembly 350, which may include clevis 362 and pin 366.
Parking brake 320 also includes an actuatoa~ 340, shown a;> a chain. Chain 340
rnay be connected to force multiplier 330 at connection point 341.
Thus, force multiplier 330 includes a lever connected to actuator 340 at a
first
position 341 on the lever 330 and is connected to the at Least one off center
connecting rod 26 at a second position, at pin 378, on the lever 330 and is
supported
by the brake cylinder 22 at a third position, at pin 366, on the lever-.
When a force is applied to actuator or chain 340, force multiplier 330 is
pulled
in direction 300. Pull direction 300 is in the opposite direction of the pull
directions
in the first and second embodiments, as shown in Figures 4-SA. l~~lultiolier
330 piwo~
about the substantially fixed pivot point or axis 332, which is def~.~~vd by
pin 378 that
connects link 380 to force multiplier 330. The pivot axis 332 is located above
off
center connecting rod 26, as viewed from the top of force multiplier 330 at
connection
point 341. Stated another way, the connection, at pin 378, of the multiplier
330 to the
off center connecting rod 26 is between the connection, at poi~~t 34 p , of
the force
multiplier 330 to the actuator 340 and the connection, at pir~ 36f,
con~~ecting brake
cylinder 22 to the force multiplier 330,
As multiplier 330 is pulled to the right (as shov,~n in Figures 6 and 6A), off
center connecting rod 26 is pulled to the Left, Off center connecting rod 26,
being
connected to the piston inside brake cylinder 22, drives piston rod 24 to the
left as
well. Piston rod 24, in turn, moves the brakes (not shown; to an applied
position on
the rail vehicle's wheels (not shown).
It is noted that the at least one off-center connecting rod 26 has been
rotated
approximately 90° from the position of the off center connecting rod
26, as shown in
CA 02434590 2003-07-08
-13-
Figures 4 and 4A and other embodiments. The off center connecting rod or rods
26
of embodiments 1-6 herein may be rotated from the positions shown in Figures 4-
9A.
FOURTH EMBODIMEIoTT
A fourth embodiment, shown in Figures 7 and 7A, is parl~aaag r:,rake 420. The
force multiplier 430 is a bifurcated U-shaped lever. The fors:e multiplier430
is
supported by the brake cylinder 22 through an assembly 45G. Assembly450 may
include collar 486, which fits around piston sleeve 25 and may also include a
collar
boss 487 with hole 463. Assemb1y450 may also include pin 492, which may be
inserted through opening 436 on force multiplier leg 434.
The opening 436 on leg 434 may be oblong in shape or of whatever shape and
size will permit substantially arcuate and somewhat vextical movement of force
multiplier 430 that occurs when force multiplier 430 is pulled in direction
400 (or, is
moved in the reverse direction by a spring or similar deuce (not shown)). The
force
in pull direction 400 causes force multiplier 430 to pivot about an axis 432
defined by
pin 492. Pin 492 has a smaller diameter than the diameter of opening 436,
shown as
an oblong opening in Figures 7 and 7A. Alternatively, a similar oblong-type
opening
can be placed, instead, at the opening whexe pin 466 is inserted, aid the
coa~nectio~ at
pin 432 may then be made such that no "play" occurs.
The force multiplier 430 is connected to the at least one o:~'f cer~tc.r
c~nraecting
rod 26 by inserting pin 466 through a clevis-type arrangement a~ one end of
force
multiplier leg 434 and then through opening 26A in off center connecting rod
26,
where pin 466 is secured (not shown).
Parking brake 420 also includes an actuator 440, sYaowrg as a chain, which may
be connected to force multiplier 430 at connection point 441 on l~aaa~dle 439.
CA 02434590 2003-07-08
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Thus, force multiplier 430 includes a Lever connected to actuator 440 at a
first
position 441 on the lever 430 and to the at Least one off center connecting
rod 26 at a
second position, pin 466, on the lever 430 and is supported by the brake
cylinder 22 at
a third position, at pin 492, on the lever.
When a force is applied to actuator or chain440, force multiplier 430 moves
in pull direction 400, which is in the opposite direction of the pull
direction described
in embodiments 1 and 2 and shown in Figures 4-5A. Force multiplier430 pivots
about a substantially fixed rotational axis 432 which is defined generally by
the
longitudinal axis of pin 492 extending through the hole 463 of continuous boss
487.
Rotational axis 432 is located above off centex connecting rod 26., when
viewed from
the top of force multiplier 430 at connectioxi point 441. Stated another way,
the
connection, by boss 487 at opening 436, of the force multiplier 430 to the
brake
cylinder 22 is between the connection, at point 441, of the force r~~ultiplier
430 to the
actuator 440 and the connection, at pin 466, connecting the at least one off
center
connecting rod 26 to the force multipliex 430.
As force multiplier 430 is pulled to the right in directioar 400 (as shown in
Figures 7 and 7A), ofF center connecting rod 26 is pulled to the Left in an
opposite
direction, and the brakes are moved to an applied position, as described iE~a
the first
embodiment.
It is noted that, in embodiments 1-3, as may be the case with other
embodiments herein and shown in their respective figures, the Linkage
connections
(i.e., 160, 260, 360) provided the ability for force multipliers 130, 230 and
330 to
have an arcuate and somewhat vertical movement when a force was applied. 1n
this
fourth embodiment, there is no such Linkage connection, and so the elongated
opening
CA 02434590 2003-07-08
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in leg 434 provides force multiplier 430 with the ability to accommodate the
arcuate
movement that occurs when a force is applied to the levers of the present
invention.
FIFTH EMBODIMEiVT
The fifth embodiment, shown in Figures 8 and 8A, is parl~ing brake 520.
Parking brake 520 is essentially the same as, and essentially functions the
same as,
parking brake 420 described in the fourth embodiment and shown in liigures 7
and
7A, but differs in the following ways. Assembly 550 may include a collar 586
that
has bifurcated boss 587, as opposed to the continuous boss487, shown in
1?igaares 7
and 7A and described in the fourth embodiment. Supporting mt:mber 550 Fxaay
also
include nut 594 to secure pin 592.
Moreover, force multiplier 530 is connected to the at least one ofd center
connecting rod 26 by a linkage 560, which may include two links 580 and two
connector pins 578 for each rod 26. This is different from the connector pin
466 and
clevis-type opening at one end of leg 434 that connects foree multiplier 430
to rod 26,
as shown in Figures 7 and 7A and described in the fourth embodiment.
In addition, force multiplier 530 pivots about a substantially fixed
rotational
axis 532, as defaned by pin 592. Thexe is no "play" in the movement about axis
532
because opening 536 on leg 534 is not elongated, and pin 592 is secured by nut
594.
As discussed above in the fourth embodiment regarding the arcuate movea~zen~
of the
force multiplier 430, in this fifth embodiment, linkage 560 is configured to
pernxit the
arcuate movement.
Thus, force multiplier 530 includes a lever that is connected to actuator 540
at
a first position, connection point 541, on the lever 530 and is connected to
the at least
one connector rod 26 at a second position, pin 578, on the lever 5 30 and is
supported
by the brake cylinder 22 at a third position, pin 592, on the lever.
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I 6-
SIXTH EMBODIMENT
A sixth embodiment, shown in Figures 9, 9A and 9B, is parking bralce 920.
The force multiplier 930 is a cam, which may include a cam handle 972 and a
cam
ramp 974. Cam 930 may also include hall bearings 930A, races 930B, a ball
S separator or cam sleeve 973 and cam ring 975. The handle 972 and ramp 974
may be
connected together as an integral unit, alone or together with cam bracket
976, or east
together as a monolithic unit. Cam ramp 974 may be a single piece or
co~~.~gured to
have more than one piece. If, for instance, ramp 974 is in two pieces, cam
bracket
976 may be configured such that it would be connected to and mate the pieces
of
ramp 974 (not shown connected or mated by ramp 974). Ii' handle 972 and ramp
974
are cast or made monolithically, bracket 976 may not be included.
Force multiplier or cam 930 may rest on or be .supported by or be attached to
brake cylinder 22 as follows. As shown in Figure 9B, brake cylinder 22 may
have a
cast boss 22A for shouldering and fastening cam 930. There may be two of these
I S bosses 22A 180° apart. Each boss 22A may have kidney or
equivalently shaped slots
22B. These slots 22B may have openings 22C for a fastening bolt 22D°
The bolts
22B would be fastened to allow the cam 930 to rotate around the. bral~e
cylinder 22.
Each slotted end (not shown) of the slotted opening 22B may be used as a cam
930
rotational stop (not shown). The cam 930 and the brake cylinder 22 may contain
a
thrust bearing 930C, which may be comprised of two races 930B, a ball
separator or
sleeve 973 and ball bearings 930A.
Alternately, cam 930 may have two kidney shaped slots, 180° apart.
T wo
bolts 22D, one per slot, may be positioned within the slot or slots and
fastened to
bosses or ears (not shown), 180° apart, cast onto the brake cylinder
22. The bolts 22D
2S may be fastened to allow the cam 930 to rotate around the brake cylinder
22. Each
CA 02434590 2003-07-08
_17_
slotted end (not shown) may be used as a cam 930 rotational step (not sl~own~.
The
cam 930 and the brake cylinder 22 may contain a thrust bearing 934C, which may
be
comprised of two races 930B, a ball separator or sleeve 973 and ball bearings
930B.
Sleeve 973 retains ball bearings 930A which race on races 9308 as shown in
Figure
S 9B.
The cam 930 may be assembled as a monolitlnc one-piece cast or machined
element or as an assembly of two or more cast ormachined parts.
Force multiplier 930 may also include follower 952 aazd may further include
an alignment plate 961. Alignment plate 961 may support follower 952 via
opening
967. Alignment plate 961 may be connected to fia~~ge 68 by, for instance,
bolts or
may be cast monolithically with flange 68.
Force multiplier 930 is connected to the at least one ofd center connecting
rod
26 by follower 952, follower brackets 9S4 and bolts 959. A first end 9S6 of
follower
952 may sit adjacent to cam 930, and a second end 9S8 may be connected to
follower
brackets 954. Follower brackets 9S4 may be connected to the at least one off
center
connecting rod 26 through bolts 959 and opening 26A of roc: 26. The :follower
brackets 954 may also be slidably connected to, or supported by, brake
cylinder 22
by, for instance, brake cylinder extension 984. Alternatively, brackets 9S4
may be
separate (single or dual) brackets connected individually or in pairs to off-
center
connecting rods 26. In addition, brackets 954 may be without any p~~aa~~ed
portion and,
therefore, not supported by the brake cylinder extension 984 or by the brake
cylinder
22 at all, except through follower 9S2 and alignment plate 961.
Parking brake 920 also includes an actuator 940, shown as a chain, which may
be connected to force multiplier 930 at connection point 94I on handle 939.
CA 02434590 2003-07-08
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When a force is applied to actuator or chain 940, force multiplier 930 is
pulled
in direction 900. Force multiplier 930 pivots or rotates about axis 964, which
is
substantially the longitudinal center line axis of bxake cylinder 22. As force
multiplier
930 is pulled in direction 900, cam ramp surface 977 rotates and also moves in
direction 900 moving follower 952 to the left in direction 900A at
substantially a 90°
angle from direction of pull 900. 'That movement of follower 952, in W rn,
pulls off
center connecting rod 26 in direction 900A causing the rai;G car's brakes to
be moved
to an applied position, as described in the first embodiment.
The arc movement of handle 939, radius of brake cylinder 22 and length of
handle 939 all may help establish the force and distance ratios of multiplier
930.
SEVENTH EMBODIlVIENT
A seventh embodiment, shown in Figures 10 and 1 GA, is J~arking brake 1020.
The force multiplier 1030, shown as a handle, may include arms 10-35, 103"J of
differing lengths, as measured linearly from the vertical plane of pivot axis
1096.
Handle 1030 may include a handle pin 1031 and handle openings J.033. 'phe
differing
lengths of arms 1035 and 1037, as measured from the vertical plane of pivot
axis
1096, may establish the force and distance ratios of force multiplier 1030.
Force multiplier 1030 is supported by a brake cylinder 22 tl-~rough a~oua~ting
plate 1065 and boss 1069. Boss 1069 may be connected i;~.~itegrailyy for
instance, by
welding, or cast monolithically with plate 1065. Mounting plate 1065 may be
connected to flange 68 on brake cylinder 22 by, for instance, bolt:y. Force
multiplier
1030 is connected to mounting plate 1065 by inserting pin I03 J. into and
through
mounting plate boss 1069 and securing pin 1031 at the other end knot shown).
Force multiplier 1030 may be pivotally connected to the at least one off
center
connecting rod 26 by assembly 1050. Assembly 1050 may include chain 1091, legs
CA 02434590 2003-07-08
-19-
1099 and pin 1066. Legs 1099 may have a clevis-type opening at one end. Chain
1091 connects to force multiplier 1030 at point 1033 and to legs 1099 at
connection
point 1099A. Legs 1099 axe connected to the at least one off center connecting
rod
via pin 1066 through a clevis-like opening on leg 1099 and further through
opening
S 26A in rod 26.
Leg or legs 1099 are configured to be essentially a one-to-one (1:1) lever but
may be configured to be a force multiplier by changing the dimension or
distance
between selected connection positions on the lever at which the lever connects
to
elements of a parking brake (e.g., a first position connecting to an actuator,
a second
position connecting to a off center connecting rod and a third position
co:anectins~ to a
brake cylinder). If the legs 1099 are so configured as ~a force mul'.tipiie~,
s~:cl~ a force
multiplier could supplement or even replace the force multiplier 1030, as
described
herein.
Force multiplier 1030 is connected to, or supported by, brake cylinder 22 via
1S flexible linkage 1060. Linkage 1060 may include chain 1091, legs 1099, pins
1078,
link 1080 and boss 1093. Chain 1091 connects force multiplier 1030 to legs
1099 at
connection point 1099A. Link 1080 connects to legs 1099 via pin 10'78 and
connects
to brake cylinder 22 via boss 1093, pin 1078 and to boss 1097 on brake
cylinder 22
via a pin or screw or equivalent connector (not shown).
Boss 1097 is an alternative to, say, boss 587 in Figure 8 or plate 165 in
Figure
4 as a way to connect a lever, such as force multiplier 1030 or a c~nverted
force
multiplier made from legs 1099, to bxake cylinder 22. Moreover, should legs
1099 be
configured as a force multiplier, the resulting force rnult~iplier may be
similar to that
of the third embodiment of Figures 6 and 6A in that the third position on tlae
lever
(e.g., where the brake cylinder supports the force multiplier) is ~etweei~ she
f'3rs~ arid
CA 02434590 2003-07-08
second positions on the lever, although the off center connecting rods 26 of
the third
embodiment are shown rotated approximately 90° from the location of the
off center
connecting rods 26 of this seventh embodiment.
When actuator or chain 1040 is pulled, it exerts a force on force multiplier
1030 in pull direction 1000. Force multiplier 1030 pivots about a
substantially fixed
rotational axis, which may be offset and in a plane substantially
perpendicular to the
longitudinal center-line axis 1064 of brake cylinder 22, as shown in Figures
10 and
10A. As force multiplier 1030 is pulled in direction 1000 and rotates about
axis 1096,
legs 1099 are pulled in direction 1000A and rotate about the axis defined by
pin 1078
and link 1080, thereby pulling off center connecting rod 26 to tF~e left (as
shown in
Figures 10 and 10A) in a direction opposite of direction 1000A, which then
moves the
rail car's brakes to an applied position, as described in the first
embodiment.
EI(sHTH EMBODIMI1,T~TT
An eighth embodiment, shown in Figures 11 and 1 1A, is parking brake 1120.
The arrangement of parking brake 1120 is similar to the arrangement of parking
brake
1020, described in the seventh embodiment and shown in ~igure;~ i 0 and 10A,
with
the, exception of what follows and 'vith the differences being evident in the
dravt.~ings
of the two embodiments.
Force multiplier 1130 may include a handle and a symmetrical curved surface
or a wheel. Force multiplier 1130 may also include handle argns :~ 138 and 1
I38A o~
differing or equal lengths, as measured from pivot axis 1196. Syrn~netrical
curved
surface or a wheel 1145 may have a radius equal to or different from the
lengths of
the arms 1138 and 1138A. The differing lengths of arm 1138 and radius
o~° wheel
1145 may help establish the force and distance ratios of multiplier 1130:
CA 02434590 2003-07-08
-21-
Force multiplier 1130 is supported by a brake cylinder z:~ through mounting
block 1198. Mounting block 1198 may be connected integrally to brake cylinder
22
by, for instance, bolts or welding, or cast with the brake cylinder 22 aS a
neono11th1C
unit. Force multiplier 1130 is connected to znouni;ing block I I c~8 by
inserting arm
1138 into hole 1198A and securing arm 1138A (the securing part is not showa~~.
Force multiplier 1130 may also be pivotally connected to the at least one ofd
center connecting rod 26 and to the brake cylinder 22, as described in the
seventh
embodiment and shown in Figures 10 and 1.0A. l~fowever, one difference from
the
seventh embodiment may be the connection between force multiplier 1030 and
lags
IO I099. In this eighth embodiment, chain portion 1140A, as shown in s figures
i 1 and
11A, serves the same function as chain 1091 in the seventh embodiment, as
shown in
Figures 10 and 10A. Chain 1140A may be connected to wheel 1145 at connectgon
point 1145A. Chain I140A will wrap around wheel 1145 as it tunas in a
counterclockwise direction 1100B.
Parking brake 1120 also includes an actuator I 140, shown as a chain. Chain
1140 may be connected to force multiplier aim 1138 at connection point I 14I .
When chain 1140 is pulled, it exerts a force on multiplier 1130 in pull
direction 1100. Force multiplier 1130 pivots about the substantially fixed
rotational
axis 1196. Rotational axis 1196 may be offset and in a plane substantially
perpendicular to the longitudinal center-line axis 1064 of brake cylinder ~2,
as shown
in Figure 10A. As chain 1140 is pulled in direction 1 i00, chain portion 1140A
is
being pulled in direction 1100A. Parking brake I 120 operates essentially the
same as
parking brake 1020 in applying the rail car's brakes.
CA 02434590 2003-07-08
-22-
NIhtTH EMB~IJ1ME1VT
A ninth embodiment, shown in Figures 12 and 12A, is parking brake 1220.
The arrangement of parking brake 1220 is similar to the arrangement of parking
brake 1120, described in the eighth embodiment and shown ia~ 1?iga~res 11 and
11A,
with the exception of what follows and with the differences teeing evident in
the
drawings of the two embodiments.
Force multiplier 1230 includes an asymmetrical curved surface element
configured substantially as shown in Figures 12 and 12A. Force multiplier 1230
may
include a boss 1279 that is connected integrally to, for instance, by welding,
or cast
monolithically with curved element 1230. Force multiplier 1230 pivots about
axis
1296. The force and distance ratios for force multiplier 1230 may be
detemnined by
the horizontal distances, measured in the same horizontal plane, between the
pivot
axis 1296 and contact point 1247, and the pivot axis 1296 and con~ct point
1249, as
shown in Figures 12 and 12A.
Force multiplier 1230 is supported by the brake cylinder 22 through piz~ 1289
and boss 1290. Boss 1290 may be connected integrally to, for instance, by
welding,
or cast monolithically with brake cylinder 22 and/or flange 68. Force
multiplier 1230
is connected to brake cylinder 22 by inserting pin 1289 into boss 1290 and
securing
pin 1289 (not shown).
Force multiplier 1230 may also be pivotally connected t~ t~.~e at least one
ofd
center connecting rod 26, as described in the seveaitla and ei;~hth
embodiments
(Figures 10-1 1A) and as shown in Figures 12 and 12A.
Chain 1240 is the actuator for parking brake 1220. Chain 1240 ~~nay be one
continuous chain (including a portion 1240A) connected to legs 1299 by pin
1278.
Chain 1240 may also be connected to force multiplier 1230 beginning at claa~n
contact
CA 02434590 2003-07-08
-23-
point 1247 and by riding along the outer surface of force multiplier 1230 to
contact
point 1249. Curved surface element 1230 is mounted ori, or cast monolithically
with,
boss 1279 at a sufficient angle to have chain 1240 wrap around the outer
surface of
force multiplier 1230 such that when chain 1240 is pulled in direction 1200,
chain
1240 clears chain portion 1240A.
When chain 1240 is pulled in direction 1200, it exerts a force on force
multiplier 1230. Force multiplier 1230 pivots about the substantially fixed
rotational
axis 1296. Rotational axis 1296 may be offset and iix a plane substantially
perpendicular to the longitudinal center-line axis 10t~4 of brake cylinder 22,
as slZOwn
in Figure 10A. As force multiplier 1230 is pulled in direction 1.200, parking
brake
1220 operates essentially the same as parking brake 1120 in applying the rail
car's
brakes.
Figure 13 shows an example of a parking brake, according to the princip~s of
this invention, installed on a rail car. Hand wheel 23 and sheave wheel 1370A
are
mounted on a rail car (not shown here). Parking brake 1320 is mounted on a
rail car
truck 10 and shown are brake cylinder 22, force multiplier 1330, actuator
chain 1340
and sheave wheel 1370B connected to brake cylinder 22. Tura~ing wheel 43 pulls
chain 1340 and parking brake 1320 operates essentially the same as described
herein
for similar embodiments in applying the rail car's brakes.
Generally, for the first six embodiments shown in Figures 4-9A herein, the
structure connecting the force multipliers to the at least one off center
connecting rod
26 may comprise only non-flexible connecting elements, such as, :for example,
clevis
162, link 280, pin 278 and follower brackets 954. Cn the other hand, for the
embodiments 7-9 shown in Figures 10-12A, that correcting structure may
comprise
both flexible and non-flexible elements.
CA 02434590 2003-07-08
_~,L~._
It should also be noted that any of the force multipliers in er~~bodiments 7-~
may be interchangeable, in that the force multiplier on any particular
embodianent
may be replaced by one of the ather force multipliers, an d the mounting
location of
the force multipliers may also be interchangeable as well.
Although the present invention has been described and illustrated in detail,
it
is to be clearly understood that the same is by way of illustration and
example only
and is not to be taken as limiting. The spirit and scope of the present
invention are to
be limited only by the terms of the appended claims.
