Description:DOUBLE DIAPHRAGM SPRING BRAKE ACTUATOR WITH DUST
SEALING ASSEMBLY FOR VEHICLE AND A METHOD THEREOF
FIELF OF THE INVENTION
The present invention relates to a brake actuator. More particularly, the present
5 invention relates to a double diaphragm spring brake actuator with dust sealing
assembly for a braking system of a vehicle which prevents dust and mud water
entering into the spring room and internal breather valve arrangement and
provides secure and precise fit, thus ensuring proper alignment and seating.
Advantageously, the present invention allows excess pressure to escape, thus
10 preventing overpressure buildup in the spring room.
BACKGROUND OF THE INVENTION
Spring Brake Actuator, also known as an Air Brake Actuator or Spring Brake
Chamber, is a critical component in the braking system of commercial vehicles,
such as trucks, buses, and trailers. It is a mechanical device that uses compressed
15 air to apply a spring-loaded brake caliper to the brake shoes, thereby slowing or
stopping the vehicle.
The actuator consists of a spring-loaded chamber that is connected to the air brake
system. When the air pressure in the chamber drops below a certain threshold,
typically due to an air leak or failure of the air brake system, the spring-loaded
20 piston extends, thus pushing the brake shoes against the rotor or drum to apply the
brakes. This ensures that the vehicle can still be safely braked, even in the event of
an air brake system failure.
Double Diaphragm Spring Brake Actuator is a type of Spring Brake Actuator that
converts the pneumatic energy into mechanical output force to apply the brakes. It
25 consists of two diaphragms, one above the other, with a spring or air chamber
between them. When the brakes are applied, the compressed air or spring force
pushes the upper diaphragm down, which in turn pushes the lower diaphragm
down, creating a pressure differential across the actuator. This pressure differential
is transmitted to a brake chamber, which contains a piston that is connected to the
3
brake shoes. The piston moves outward, pushing the brake shoes against the rotor
or drum to apply the brakes.
Some of the prior arts are:
US2017057480A1 discloses a pull style double diaphragm spring brake actuator
5 comprising actuator's operating rod is pulled toward the actuator to apply the
brake. The actuator's parking brake release piston is located closer to the brake
than the service brake piston, and the parking brake power spring is positioned
between the mounting end of the actuator and the parking brake piston such that
when parking brake release pressure is removed from the parking brake release
10 chamber the parking brake piston biases the operating rod in the brake application
direction, drawing the operating rod further into the actuator. The operating rod
may penetrate the parking brake piston and an intermediate flange between the
parking brake piston and the service brake piston and be connected to the service
brake piston such that the service brake piston may control brake application
15 when the parking brake piston is in its parking brake release position adjacent to
the end of the actuator that is mounted to the brake.
CN103742571A discloses a double-diaphragm spring brake air chamber for
commercial vehicle brake system comprising a connecting cover (1), a front push
plate, a central shaft (2) and diaphragms (5), the central shaft (2) penetrates a
20 central hole of the connecting cover (1), the front end of the central shaft is
connected with the front push plate through a screw, a rear push plate A (4) and a
rear push plate B (6) are fixedly clamped at the rear end of the central shaft (2)
through screws (3), and the diaphragms (5) are clamped between the rear push
plate A (4) and the rear push plate B (6). By the aid of the technical scheme,
25 product structures are simplified, product failures are decreased, production cycle
is shortened, productivity and durability of products are improved, so that product
performances are improved, the service lives of the products are prolonged, and a
truck brake system is safer.
4
US3730056A discloses a double diaphragm brake operator improvements
comprising two diaphragms placed close to each other therewithin and held in
position inside the chamber by a clamp band, the outer or outboard (with respect
to the axle or brake) one of said diaphragms having a separate air pressure input
5 on the outer shell of the chamber, a perforated ring spacing said two diaphragms
with an air inlet connected to said perforation for feeding air between said
diaphragms and means for effectively sealing the peripheral zones of said
diaphragms with respect to said ring and clamp band, particularly including means
preventing extrusion of the diaphragms at the connection points of the clamp band
10 halves.
US3908520A discloses an adjustment means for double diaphragm spring brake
chamber actuator comprising a release mechanism for a double diaphragm spring
brake actuator utilizes a threaded rod having a portion extending outwardly from
the brake chamber housing and a portion telescopically positioned within a
15 movable piston in the emergency brake chamber. The threaded rod may have the
exterior portion covered by a removable cup. The piston within the emergency
brake chamber is free to move the entire length of the release bolt, but yet only a
portion of the release bolt extends outwardly from the brake chamber housing.
However, the conventional double diaphragm spring brake actuator as discussed
20 in the prior art have vent holes to expel air when the spring is compressed. This
allows dust and moisture to enter the spring room, leading to rust and potential
spring failure over time. The presence of dust and moisture increases the
frequency of maintenance required. Rust and debris cause wear and tear on the
internal components, reducing the overall lifespan of the actuator. Contaminants
25 entering the spring room affects the performance of the brake actuator, thus
leading to less reliable braking over time. Conventional designs are more
susceptible to environmental conditions, such as rain and dust, which compromise
the actuator’s functionality.
Accordingly, there is a need for an improved double diaphragm spring brake
30 actuator with dust sealing assembly for a vehicle which provides a more robust
5
seal that prevents contaminants from entering the spring room, thereby enhancing
the durability and reliability of the brake actuator.
OBJECT OF THE INVENTION
The principal object of the present invention is to provide a double diaphragm
5 spring brake actuator with dust sealing assembly for a vehicle.
Another object of the invention is to provide a double diaphragm spring brake
actuator with dust sealing assembly which protects the internal components from
dust and debris by dust sealing arrangement, which can significantly extend the
lifespan of the actuator.
10 Another object of the invention is to provide a double diaphragm spring brake
actuator with dust sealing assembly which maintains consistent performance over
time by keeping the spring room clean, thus reducing the risk of failure and
ensuring reliable braking.
Another object of this invention is to provide a double diaphragm spring brake
15 actuator with dust sealing assembly which minimizes the ingress of contaminants,
which provides less frequent maintenance and lower overall maintenance costs.
SUMMARY OF THE INVENTION
It is a primary aspect of the present invention to provide A double diaphragm
spring brake actuator (100) with dust sealing assembly (25) for a vehicle,
20 comprising: a service brake (1) comprising a diaphragm (3), a push rod with
clevis assembly (4), a non-pressure plate assembly (5), and a return spring (6), and
a parking brake (2) comprising a rear shell (7), a power spring (8), a spring guide
(9) having at least two grooves (9a, 9b), and an outer surface (9c), an adaptor (10),
a diaphragm (11), a pusher rod assembly (12), a flange (13), a spring room (14),
25 an internal breather valve arrangement (15), a plug (16) and a dust sealing
assembly (25).
The dust sealing assembly (25) comprising:
6
i. a primary sealing member (22) comprises a dust plug (17) having a groove
(22a), an outer surface (22b), an outer flap (22c), and at least two to four
slits (22d), where the dust plug groove (22a) and dust plug outer surface
(22b) is configured to tightly locked with rear shell (7), the dust plug outer
5 flap (22c) configured to seal the outer surface of the rear shell (7b), that
prevents larger contaminant particles and mud water from entering into the
spring room (14) and the internal breather valve arrangement (15), and at
least two to four slits (22d) configured to deplete the over pressure built
inside the spring room (14) during parking brake (2) released condition;
10 ii. a secondary sealing member (23) comprises a seal (18) having a sealing
beads (18a) and a sealing globule (18b) and a seal guide (19) having a
bump (19a), an inner groove (19b) and at least three or more protrusions
(19c), where the seal guide (19) and the seal (18) are axially inserted by
applying a load on three or more protrusions (19c) of the seal guide (19),
15 fitting into their respective groove on outside of the spring guide (9b), the
sealing beads (18a) on the seal (18) prevents dust and mud water from
entering into the spring room (14) that seals the path between the rear shell
(7) and the seal (18), the sealing globule (18b) on the seal (18) prevents
dust entry in the path between the spring guide (9) and the seal (17), and
20 the sealing beads (18a) and the sealing globule (18b) prevent dust and mud
water from entering into the spring room (14) when a minor load is acting
on the seal (18) and the seal guide (19) during the parking brake (2) is
released condition, thus provide a better sealing between the rear shell (7)
and the spring guide (9), and
25 iii. a tertiary sealing member (24) comprises a snug fit retainer (20) having a
groove (20a) and an O-ring (21), where the O-Ring (21) and the snug fit
retainer (20) are axially inserted in the groove (9a) on inside of the spring
guide (9), and the O-ring (21) radially seals to prevent dust and mud water
entering into the spring room (14) and the internal breather valve
30 arrangement (15).
7
Another aspect of the present invention is to provide a method of working of a
double diaphragm spring brake actuator (100) with dust sealing assembly (25) for
a vehicle as claimed in claim 1, said method comprises steps of:
a. compressing or caging the power spring (8) of the parking brake
5 (2) by an air pressure applied in an inlet port of the parking brake
(2) chamber during vehicle normal running condition, where the
power spring (8) configured to remain compressed or caged until
the parking brake (2) is applied;
b. supplying a pressurized air from the reservoir to the chamber inlet
10 port of the service brake (1) and acting on the diaphragm (3) in the
chamber of the service brake (1) when the service brake (1) is
applied and the dust plug (17), damage it, or fall out from the rear
shell (7), thus the secondary sealing member (23) and a tertiary
sealing member (24) prevents dust and mud water entry into the
15 spring room (14) and the internal breather valve arrangement (15)
through the passage of wind off rod hole on the rear shell (7);
c. releasing the air pressure from the chamber of the parking brake (2)
to the atmosphere through a graduated hand control valve when the
parking brake (2) is applied, that allows the power spring (8), the
20 diaphragm (11), the spring guide (9), and the pusher rod assembly
(12) to extend and transfers the spring force to the slack adjuster
through the push rod with clevis assembly (4), thereby increasing
the volume in the spring room (14) and creating a vacuum pressure
in the spring room (14) depleted by atmospheric air flows from the
25 service brake (1) chamber through the dual brake valve, the relay
valve, the modulator valve and the quick release valve into the
spring room (14) through the internal breather valve arrangement
(15), thus dust plug outer flap (22c) of the primary sealing member
(22) configured to seal the outer surface of the rear shell (7b) to
30 prevent dust and mud water from entering into the spring room
(14);
8
d. applying the air pressure to the inlet port of the parking brake (2)
chamber through the graduated hand control valve during the
parking brake release condition to allow the air to enter the
chamber and causes the power spring (8) to start compressing by
5 using the spring guide (9) and the diaphragm (11), and moving and
releasing the parking brake (2) by the pusher rod assembly (12) as
the power spring (8) compresses to allows the vehicle to move
freely, where the movement of the power spring (8) reduces the
volume in the spring room (14) which causes an overpressure to
10 build up in the spring room (14) prevented by the internal breather
valve arrangement (15) and the dust plug (17) of the primary
sealing member (22), thus preventing dust and water from entering
into the spring room (14) through the dust plug (17), the seal (18),
and the O-Ring (21) and allowing the excess pressure to escape
15 through the internal breather valve arrangement (15) and the dust
plug (17);
e. releasing the brakes manually by the driver by unplugging the dust
plug (17) from the rear shell (7) if the vehicle fails or is halted due
to parking brake failure to allow access to the internal mechanisms
20 of the actuator and compress the power spring (8) using a wind-off
rod that disengages the brakes and allow the vehicle to be moved,
where after moving the vehicle, the driver forgets to reinsert the
dust plug (17), damage it, or fall out from the rear shell (7), thereby
the secondary sealing member (23) and the tertiary sealing (24)
25 prevent dust, mud, and water from entering into the spring room
(14) and internal breather valve arrangement (15), and
f. engaging the service brake (1) and the parking brake (2)
simultaneously for enhanced vehicle control during a compounding
brake application, where the air pressure depletes from the inlet
30 port of the parking brake (2) chamber and applies to the inlet port
of the service brake (1) chamber, thus allows the air pressure to
9
flow from the service brake (1) chamber to the spring room (14)
through the internal breather valve arrangement (15) by closing of
hole in the pusher rod assembly (12) using the plug (16) to ensures
that the air pressure dynamics remain stable and that the actuator
5 functions properly without unwanted air flow, and prevents the
entry of dust and mud water into the spring room (14) and the
internal breather valve arrangement (15) by the dust plug (17) of
the primary sealing member (22).
10 BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a view of a double diaphragm spring brake actuator with dust sealing
assembly for a vehicle according to the present invention.
Figure 2 is a view of a double diaphragm spring brake actuator with dust sealing
assembly for a vehicle according to the present invention.
15 Figure 3 is a view of a double diaphragm spring brake actuator with dust sealing
assembly for a vehicle when device is in parking brake applied condition
according to the present invention.
Figure 4 is a view of a dust plug of a primary sealing member of a double
diaphragm spring brake actuator with dust sealing assembly for a vehicle
20 according to the present invention.
Figure 5 is a view of a double diaphragm spring brake actuator with dust sealing
assembly for a vehicle when device is in parking brake release condition
according to the present invention.
Figure 6 is a view of a dust plug of a primary sealing member is in unplugged/fall
25 down condition and the secondary and tertiary sealing arrangements of double
diaphragm spring brake actuator according to the present invention.
10
Figure 7 is a view of a double diaphragm spring brake actuator with dust sealing
assembly for a vehicle when the parking brake and service brake both are in
applied condition according to the present invention.
Figure 8 is a detailed view of a dust plug of a primary sealing member according
5 to the present invention.
Figure 9 is a detailed view of a seal guide of a secondary sealing member
according to the present invention.
Figure 10 is a detailed view of a seal of a secondary sealing member according to
the present invention.
10 Figure 11 is a detailed view of a snug fit retainer of a tertiary sealing member
according to the present invention.
Figure 12 is a detailed view of a spring guide and rear shell according to the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
15 The present invention as embodied by a “a double diaphragm spring brake
actuator (100) with dust sealing assembly (25) for a vehicle and method thereof”
succinctly fulfils the above-mentioned need[s] in the art. The present invention
has objective[s] arising because of the above-mentioned need[s], said objective[s]
having been enumerated herein above.
20 The following description is directed to a double diaphragm spring brake actuator
(100) with dust sealing assembly (25) for a vehicle and a method thereof as much
as the objective(s) of the present invention are enumerated, it will be obvious to a
person skilled in the art that, the enumerated objective(s) are not exhaustive of the
present invention in its entirety and are enclosed solely for the purpose of
25 illustration. Further, the present invention encloses within its scope and purview,
any structural alternative(s) and/or any functional equivalent(s) even though, such
structural alternative(s) and/or any functional equivalent(s) are not mentioned
explicitly herein or elsewhere, in the present disclosure. The present invention
11
therefore encompasses also, any improvisation[s]/modification[s] applied to the
structural alternative[s]/functional alternative[s] within its scope and purview. The
present invention may be embodied in other specific form[s] without departing
from the essential attributes thereof.
5 Furthermore, the terms and phrases used herein are not intended to be limiting, but
rather are to provide an understandable description. Throughout this specification,
the use of the word "comprises" and variations such as "comprises" and
"comprising" may imply the inclusion of an element or elements not specifically
recited.
10 The conventional double diaphragm spring brake actuator vent holes to expel air
when the spring is compressed. This allows dust and moisture to enter the spring
room, leading to rust and potential spring failure over time. The presence of dust
and moisture increases the frequency of maintenance required. Rust and debris
cause wear and tear on the internal components, reducing the overall lifespan of
15 the actuator. Contaminants entering the spring room affects the performance of the
brake actuator, thus leading to less reliable braking over time. Conventional
designs are more susceptible to environmental conditions, such as rain and dust,
which compromise the actuator’s functionality.
But in the case of the present invention, the improved double diaphragm spring
20 brake actuator with dust sealing assembly for a vehicle provides a more robust
seal that prevents contaminants from entering into the spring room, thereby
enhancing the durability and reliability of the brake actuator.
Referring to Figure 1 to 12, in an embodiment of the present invention, provides a
double diaphragm spring brake actuator (100) with dust sealing assembly (25) for
25 a vehicle, comprising: a service brake (1) comprising a diaphragm (3), a push rod
with clevis assembly (4), a non-pressure plate assembly (5), and a return spring
(6), and a parking brake (2) comprising a rear shell (7), a power spring (8), a
spring guide (9) having at least two grooves (9a, 9b), and an outer surface (9c), an
adaptor (10), a diaphragm (11), a pusher rod assembly (12), a flange (13), a spring
12
room (14), an internal breather valve arrangement (15), a plug (16) and a dust
sealing assembly (25).
The dust sealing assembly (25) comprising: a primary sealing member (22)
comprises a dust plug (17) having a groove (22a), an outer surface (22b), an outer
5 flap (22c), and at least two to four slits (22d), where the dust plug groove (22a)
and the dust plug outer surface (22b) is configured to tightly locked with rear shell
(7), the dust plug outer flap (22c) configured to seal the outer surface of the rear
shell (7b), that prevents larger contaminant particles and mud water from entering
into the spring room (14) and the internal breather valve arrangement (15), and at
10 least two to four slits (22d) configured to deplete the over pressure built inside the
spring room (14) during the parking brake (2) released condition, a secondary
sealing member (23) comprises a seal (18) having a sealing beads (18a) and a
sealing globule (18b) and a seal guide (19) having a bump (19a), an inner groove
(19b) and at least three or more protrusions (19c), where the seal guide (19) and
15 the seal (18) are axially inserted by applying a load on three or more protrusions
(19c) of the seal guide (19), fitting into their respective groove on outside of the
spring guide (9b), the sealing beads (18a) on the seal (18) prevents dust and mud
water from entering into the spring room (14) that seals the path between the rear
shell (7) and the seal (18), the sealing globule (18b) on the seal (18) prevents dust
20 entry in the path between the spring guide (9) and the seal (17), and the sealing
beads (18a) and the sealing globule (18b) prevent dust and mud water from
entering into the spring room (14), when a minor load is acting on the seal (18)
and the seal guide (19) during the parking brake (2) is released condition, thus
provide a better sealing between the rear shell (7) and the spring guide (9), and a
25 tertiary sealing member (24) comprises a snug fit retainer (20) having a groove
(20a) and an O-ring (21), where the O-Ring (21) and the snug fit retainer (20) are
axially inserted in the groove (9a) on inside of the spring guide (9), and the O-ring
(21) radially seals to prevent dust and mud water entering into the spring room
(14) and the internal breather valve arrangement (15).
13
In the preferred embodiment of the present invention, the secondary sealing
member (23) and the tertiary sealing member (24) configured to assemble in their
respective grooves of the spring guide (9) by a press fit, thread joint, riveting,
pasting and gluing.
5 In the preferred embodiment of the present invention, the seal (18) configured to
assemble on the seal guide (19) in their respective groove by a press fit, riveting,
pasting and gluing.
In the preferred embodiment of the present invention, the seal (18) configured to
assemble in its respective bump (19a) of the seal guide (19) by a press fit, riveting,
10 pasting and gluing.
In the preferred embodiment of the present invention, the O-Ring (21) configured
to assemble in the snug fit retainer (20) in its respective groove (20a).
In the preferred embodiment of the present invention, the sealing beads (18a)
configured to radially seal with the inner surface (7a) of the rear shell (7) and the
15 sealing globule (18b) face sealing with the outer surface (9c) of the spring guide
(9).
In the preferred embodiment of the present invention, the sealing beads (18a) and
the sealing globule (18b) is selected from round, oval, D shape, square, and
rectangular.
20 In the preferred embodiment of the present invention, the dust plug (17)
configured to assemble on the rear shell (7) of the parking brake (2) using
interference fit or riveting.
Another embodiment of the present invention is to provide a method of working
double diaphragm spring brake actuator (100) with dust sealing assembly (25) for
25 a vehicle, said method comprises steps of:
a. compressing or caging the power spring (8) of the parking brake
(2) by an air pressure applied in an inlet port of the parking brake
(2) chamber during vehicle normal running condition, where the
14
power spring (8) configured to remain compressed or caged until
the parking brake (2) is applied;
b. supplying a pressurized air from the reservoir to the chamber inlet
port of the service brake (1) and acting on the diaphragm (3) in the
5 chamber of the service brake (1) when the service brake (1) is
applied and the dust plug (17), damage it, or fall out from the rear
shell (7), thus the secondary sealing member (23) and the tertiary
sealing member (24) prevents dust and mud water entry into the
spring room (14) and the internal breather valve arrangement (15)
10 through the passage of wind off rod hole on the rear shell (7);
c. releasing the air pressure from the chamber of the parking brake (2)
to the atmosphere through a graduated hand control valve when the
parking brake (2) is applied, that allows the power spring (8), the
diaphragm (11), the spring guide (9), and the pusher rod assembly
15 (12) to extend and transfers the spring force to the slack adjuster
through the push rod with clevis assembly (4), thereby increasing
the volume in the spring room (14) and creating a vacuum pressure
in the spring room (14) depleted by atmospheric air flows from the
service brake (1) chamber through the dual brake valve, the relay
20 valve, the modulator valve and the quick release valve into the
spring room (14) through the internal breather valve arrangement
(15), thus dust plug outer flap (22c) of the primary sealing member
(22) configured to seal the outer surface of the rear shell (7b) to
prevent dust and mud water from entering into the spring room
25 (14);
d. applying the air pressure to the inlet port of the parking brake (2)
chamber through the graduated hand control valve during the
parking brake release condition to allow the air to enter the
chamber and causes the power spring (8) to start compressing by
30 using the spring guide (9) and the diaphragm (11), and moving and
releasing the parking brake (2) by the pusher rod assembly (12) as
15
the power spring (8) compresses to allows the vehicle to move
freely, where the movement of the power spring (8) reduces the
volume in the spring room (14) which causes an overpressure to
build up in the spring room (14) prevented by the internal breather
5 valve arrangement (15) and the dust plug (17) of the primary
sealing member (22), thus preventing dust and water from entering
into the spring room (14) through the dust plug (17), the seal (18),
and the O-Ring (21) and allowing the excess pressure to escape
through the internal breather valve arrangement (15) and the dust
10 plug (17);
e. releasing the brakes manually by the driver by unplugging the dust
plug (17) from the rear shell (7) if the vehicle fails or is halted due
to parking brake failure to allow access to the internal mechanisms
of the actuator and compress the power spring (8) using a wind-off
15 rod that disengages the brakes and allow the vehicle to be moved,
where after moving the vehicle, the driver forgets to reinsert the
dust plug (17), damage it, or fall out of the rear shell (7), thereby
the secondary sealing member (23) and the tertiary sealing member
(24) prevent dust, mud, and water from entering into the spring
20 room (14) and the internal breather valve arrangement (15), and
f. engaging the service brake (1) and the parking brake (2)
simultaneously for enhanced vehicle control during a compounding
brake application, where the air pressure depletes from the inlet
port of the parking brake (2) chamber and applies to the inlet port
25 of the service brake (1) chamber, thus allows the air pressure to
flow from the service brake (1) chamber to the spring room (14)
through the internal breather valve arrangement (15) by closing of
hole in the pusher rod assembly (12) using the plug (16) to ensures
that the air pressure dynamics remain stable and that the actuator
30 functions properly without unwanted air flow, and prevents the
entry of dust and mud water into the spring room (14) and the
16
internal breather valve arrangement (15) by the dust plug (17) of
the primary sealing member (22).
In the preferred embodiment of the present invention, the pressure energy is
converted into linear mechanical force and transfer it to a 'S'-cam through the push
5 rod with clevis assembly (4) and a slack adjuster, thus causing the brake shoes to
be applied when the service brake (1) is applied.
In the preferred embodiment of the present invention, the linear motion is
converted into rotary motion by using the slack adjuster to transfers the output
force to the ‘S’ cam shaft when the parking brake (2) is applied.
10
WORKING EXAMPLE
An exemplary embodiment discloses a double diaphragm spring brake actuator
(100) with dust sealing assembly (25) for a vehicle comprising: a service brake (1)
comprising a diaphragm (3), a push rod with clevis assembly (4), a non-pressure
15 plate assembly (5), and a return spring (6), and a parking brake (2) comprising a
rear shell (7), a power spring (8), a spring guide (9) having at least two grooves
(9a, 9b), and an outer surface (9c), an adaptor (10), a diaphragm (11), a pusher rod
assembly (12), a flange (13), a spring room (14), an internal breather valve
arrangement (15), a plug (16) and a dust sealing assembly (25).
20 The dust sealing assembly (25) comprising:
(i) a primary sealing member (22) comprises a dust plug (17) having a
groove (22a), an outer surface (22b), an outer flap (22c), and at least
two to four slits (22d), where the dust plug groove (22a) and the dust
plug outer surface (22b) is configured to tightly locked with the rear
25 shell (7), the dust plug outer flap (22c) configured to seal the outer
surface of the rear shell (7b), that prevents larger contaminant particles
and mud water from entering into the spring room (14) and the internal
breather valve arrangement (15), and at least two to four slits (22d)
17
configured to deplete the over pressure built inside the spring room
(14) during parking brake (2) released condition;
(ii) a secondary sealing member (23) comprises a seal (18) having a
sealing beads (18a) and a sealing globule (18b) and a seal guide (19)
5 having a bump (19a), an inner groove (19b) and at least three or more
protrusions (19c), where the seal guide (19) and the seal (18) are
axially inserted by applying a load on three or more protrusions (19c)
of seal guide (19), fitting into their respective groove on outside of the
spring guide (9b), the sealing beads (18a) on the seal (18) prevents
10 dust and mud water from entering into the spring room (14) that seals
the path between the rear shell (7) and the seal (18), the sealing globule
(18b) on the seal (18) prevents dust entry in the path between the
spring guide (9) and the seal (18), and the sealing beads (18a) and the
sealing globule (18b) prevent dust and mud water from entering into
15 the spring room (14), when a minor load is acting on the seal (18) and
the seal guide (19) during the parking brake (2) is released condition,
thus provides better sealing between the rear shell (7) and the spring
guide (9); and
(iii) a tertiary sealing member (24) comprises a snug fit retainer (20) having
20 a groove (20a) and an O-ring (21), where the O-Ring (21) and the snug
fit retainer (20) are axially inserted in the groove (9a) on inside of the
spring guide (9), and the O-ring (21) radially seals to prevent dust and
mud water entering into the spring room (14) and the internal breather
valve arrangement (15).
25 Working
The double diaphragm spring brake actuator with dust sealing assembly for a
braking system of a vehicle working on following conditions:
(i) during vehicle normal running condition, the power spring (8) of the
parking brake (2) is compressed or caged by an air pressure applied in a chamber
18
inlet port of the parking brake (2), where the power spring (8) remains
compressed or caged until the parking brake (2) is applied.
(ii) when the service brake (1) is applied and the dust plug (17), damage it, or
fall out from the rear shell (7), a pressurized air is supplied from the reservoir to
5 the chamber inlet port of the service brake (1) and act on the diaphragm (3) in the
chamber of the service brake (1), the pressure energy is converted into linear
mechanical force and transfer it to a 'S'-cam through the push rod with clevis
assembly (4) and a slack adjuster, thus causing the brake shoes to be applied, thus
the secondary sealing member (23) and the tertiary sealing member (24) prevents
10 dust and mud water entry into the spring room (14) and internal breather valve
arrangement (15) through the passage of wind off rod hole on the rear shell (7).
(iii) when the parking brake (2) is applied, the air pressure from the chamber of
the parking brake (2) is released to the atmosphere through a graduated hand
control valve, that allows the power spring (8), the diaphragm (11), the spring
15 guide (9), and the pusher rod assembly (12) to extend and transfers the spring
force to the slack adjuster through the push rod with clevis assembly (4), the slack
adjuster converts the linear motion into rotary motion and transfers the output
force to the ‘S’ cam shaft, thereby increasing the volume in the spring room (14)
and creating a vacuum pressure in the spring room (14) depleted by atmospheric
20 air flows from the service brake (1) chamber through the dual brake valve, the
relay valve, the modulator valve and the quick release valve into the spring room
(14) through the internal breather valve arrangement (15), thus dust plug outer
flap (22c) of the primary sealing member (22) seals the outer surface of the rear
shell (7b) to prevent dust and mud water from entering into spring room (14).
25 (iv) during the parking brake release condition, the air pressure is applied into
the inlet port of the parking brake (2) chamber through the graduated hand control
valve, that allows the air to enter the chamber and causes the power spring (8) to
start compressing by using the spring guide (9) and the diaphragm (11), the pusher
rod assembly (12) configured to move and release the parking brake (2) as the
30 power spring (8) compresses, thus allows the vehicle to move freely, where the
19
movement of the power spring (8) reduces the volume in the spring room (14)
which causes an overpressure to build up in the spring room (14) that is prevented
by the internal breather valve arrangement (15) and the dust plug (17) of the
primary sealing member (22), thus preventing dust and water from entering into
5 the spring room (14) through the dust plug (17), the seal (18), O-Ring (21) and
allowing the excess pressure to escape through the internal breather valve
arrangement (15) and the dust plug (17).
(v) if the vehicle fails or is halted due to parking brake failure, the driver
releases the brakes manually by unplugging the dust plug (17) from the rear shell
10 (7) that allows access to the internal mechanisms of the actuator and compresses
the power spring (8) using a wind-off rod that disengages the brakes and allows
the vehicle to be moved, where after moving the vehicle, the driver forget to
reinsert the dust plug (17), damage it, or fall out of the rear shell (7), and the
secondary sealing member (23) and the tertiary sealing (24) configured to prevent
15 dust, mud, and water from entering into the spring room (14) and the internal
breather valve arrangement (15).
(vi) during a compounding brake application, the service brake (1) and the
parking brake (2) are engaged simultaneously for enhanced vehicle control, the air
pressure depletes from the inlet port of the parking brake (2) chamber and apply to
20 the inlet port of the service brake (1) chamber, thus allows the air pressure to flow
from the service brake (1) chamber to the spring room (14) through the internal
breather valve arrangement (15) by closing of hole in pusher rod assembly (12)
using the plug (16), thus ensures that the air pressure dynamics remain stable and
that the actuator functions properly without unwanted air flow, and prevents the
25 entry of dust and mud water into the spring room (14) and the internal breather
valve arrangement (15) by the dust plug (17) of the primary sealing member (22).
ADVANTAGE OF THE PRESENT INVENTION
20
The present invention relates to a double diaphragm spring brake actuator for a
braking system of a vehicle which provides a tight seal around the spring room,
preventing dust, dirt, and moisture from entering into the spring room, thus
ensures that the spring remains clean and dry, which is essential for maintaining
5 proper braking performance.
The present invention relates to a double diaphragm spring brake actuator which
prevents corrosion on the spring and other components by preventing dust, dirt,
and moisture from entering into the spring room, thus extends the lifespan of the
actuator and reduces the risk of premature failure.
10 The present invention relates to a double diaphragm spring brake actuator which
ensures that air pressure dynamics are maintained within the actuator, which is
critical for proper braking performance and ensures that the brakes operate
consistently and effectively by preventing air leaks and maintaining proper
pressure.
15 The present invention relates to a double diaphragm spring brake actuator which
reduces noise generated by the actuator due to reduced air leaks and improved air
pressure dynamics.
It will be apparent to a person skilled in the art that the above description is for
illustrative purposes only and should not be considered as limiting. Various
20 modifications, additions, alterations, and improvements without deviating from
the spirit and the scope of the invention may be made by a person skilled in the
art.
21
LIST OF NUMERALS:
(1). Service brake
(2). Parking brake
(3). Diaphragm
5 (4). Push rod with clevis assembly
(5). Non-pressure plate assembly
(6). Return spring
(7). Rear shell
(7a). Inner surface
10 (7b). Outer surface
(8). Power spring
(9). Spring guide
(9a, 9b). two grooves
(9c). Outer surface
15 (10). Adaptor
(11). Diaphragm
(12). Pusher rod assembly
(13). Flange
(14). Spring room
20 (15). Internal breather valve arrangement
(16). Plug
(17). Dust plug
(18). Seal
(18a). Sealing beads
25 (18b). Sealing globule
(19). Seal guide
(19a). Bump
(19b). Inner groove
22
(19c). Three Protrusions
(20). Snug fit retainer
(20a). Groove
(21). O-ring
5 (22). Primary sealing member
(22a). Groove
(22b). Outer surface
(22c). Outer flap
(22d). Two slits
10 (23). Secondary sealing member
(24). Tertiary sealing member
(25). Dust sealing assembly
(100). Double diaphragm spring brake actuator
15
, C , Claims:WE CLAIM:
1. A double diaphragm spring brake actuator (100) with dust sealing
assembly (25) for a vehicle, comprising:
a. a service brake (1) comprising a diaphragm (3), a push rod with
5 clevis assembly (4), a non-pressure plate assembly (5), and a return
spring (6), and
b. a parking brake (2) comprising a rear shell (7), a power spring (8),
a spring guide (9) having at least two grooves (9a, 9b), and an
outer surface (9c), an adaptor (10), a diaphragm (11), a pusher rod
10 assembly (12), a flange (13), a spring room (14), an internal
breather valve arrangement (15), a plug (16) and a dust sealing
assembly (25),
characterized in that the dust sealing assembly (25) comprising:
i. a primary sealing member (22) comprises a dust plug
15 (17) having a groove (22a), an outer surface (22b), an
outer flap (22c), and at least two to four slits (22d),
where the dust plug groove (22a) and dust plug outer
surface (22b) is configured to tightly locked with rear
shell (7), the dust plug outer flap (22c) configured to
20 seal the outer surface of the rear shell (7b), that
prevents larger contaminant particles and mud water
from entering into the spring room (14) and the
internal breather valve arrangement (15), and at least
two to four slits (22d) configured to deplete the over
25 pressure built inside the spring room (14) during
parking brake (2) released condition;
ii. a secondary sealing member (23) comprises a seal
(18) having a sealing beads (18a) and a sealing
globule (18b) and a seal guide (19) having a bump
30 (19a), an inner groove (19b) and at least three or more
protrusions (19c), where the seal guide (19) and the
24
seal (18) are axially inserted by applying a load on
three or more protrusions (19c) of the seal guide (19),
fitting into their respective groove on outside of the
spring guide (9b), the sealing beads (18a) on the seal
5 (18) prevents dust and mud water from entering into
the spring room (14) that seals the path between the
rear shell (7) and the seal (18), the sealing globule
(18b) on the seal (18) prevents dust entry in the path
between the spring guide (9) and the seal (17), and the
10 sealing beads (18a) and the sealing globule (18b)
prevent dust and mud water from entering into the
spring room (14) when a minor load is acting on the
seal (18) and the seal guide (19) during the parking
brake (2) is released condition, thus provide a better
15 sealing between the rear shell (7) and the spring guide
(9), and
iii. a tertiary sealing member (24) comprises a snug fit
retainer (20) having a groove (20a) and an O-ring
(21), where the O-Ring (21) and the snug fit retainer
20 (20) are axially inserted in the groove (9a) on inside
of the spring guide (9), and the O-ring (21) radially
seals to prevent dust and mud water entering into the
spring room (14) and the internal breather valve
arrangement (15).
25
2. The double diaphragm spring brake actuator (100) as claimed in claim 1,
wherein the secondary sealing member (23) and the tertiary sealing
member (24) configured to assemble in their respective grooves of spring
guide (9) by a press fit, thread joint, riveting, pasting and gluing.
30
25
3. The double diaphragm spring brake actuator (100) as claimed in claim 1,
wherein the seal (18) configured to assemble on the seal guide (19) in their
respective groove by a press fit, riveting, pasting and gluing.
5 4. The double diaphragm spring brake actuator (100) as claimed in claim 1,
wherein the seal (18) configured to assemble in its respective bump (19a)
of the seal guide (19) by a press fit, riveting, pasting and gluing.
5. The double diaphragm spring brake actuator (100) as claimed in claim 1,
10 wherein the O-Ring (21) configured to assemble in the snug fit retainer
(20) in its respective groove (20a).
6. The double diaphragm spring brake actuator (100) as claimed in claim 1,
wherein the sealing beads (18a) configured to radially seal with the inner
15 surface (7a) of the rear shell (7) and the sealing globule (18b) face sealing
with the outer surface (9c) of the spring guide (9).
7. The double diaphragm spring brake actuator (100) as claimed in claim 1,
wherein the sealing beads (18a) and the sealing globule (18b) selected
20 from round, oval, D shape, square, and rectangular.
8. The double diaphragm spring brake actuator (100) as claimed in claim 1,
wherein the dust plug (17) configured to assemble on the rear shell (7) of
the parking brake (2) using interference fit or riveting.
25
9. A method of working of a double diaphragm spring brake actuator (100)
with dust sealing assembly (25) for a vehicle as claimed in claim 1, said
method comprises steps of:
a. compressing or caging the power spring (8) of the parking brake
30 (2) by an air pressure applied in an inlet port of the parking brake
(2) chamber during vehicle normal running condition, where the
26
power spring (8) configured to remain compressed or caged until
the parking brake (2) is applied;
b. supplying a pressurized air from the reservoir to the chamber inlet
port of the service brake (1) and acting on the diaphragm (3) in the
5 chamber of the service brake (1) when the service brake (1) is
applied and the dust plug (17), damage it, or fall out from the rear
shell (7), thus the secondary sealing member (23) and a tertiary
sealing member (24) prevents dust and mud water entry into the
spring room (14) and the internal breather valve arrangement (15)
10 through the passage of wind off rod hole on the rear shell (7);
c. releasing the air pressure from the chamber of the parking brake (2)
to the atmosphere through a graduated hand control valve when the
parking brake (2) is applied, that allows the power spring (8), the
diaphragm (11), the spring guide (9), and the pusher rod assembly
15 (12) to extend and transfers the spring force to the slack adjuster
through the push rod with clevis assembly (4), thereby increasing
the volume in the spring room (14) and creating a vacuum pressure
in the spring room (14 depleted by atmospheric air flows from the
service brake (1) chamber through the dual brake valve, the relay
20 valve, the modulator valve and the quick release valve into the
spring room (14) through the internal breather valve arrangement
(15), thus dust plug outer flap (22c) of the primary sealing member
(22) configured to seal the outer surface of the rear shell (7b) to
prevent dust and mud water from entering into the spring room
25 (14);
d. applying the air pressure to the inlet port of the parking brake (2)
chamber through the graduated hand control valve during the
parking brake release condition to allow the air to enter the
chamber and causes the power spring (8) to start compressing by
30 using the spring guide (9) and the diaphragm (11), and moving and
releasing the parking brake (2) by the pusher rod assembly (12) as
27
the power spring (8) compresses to allows the vehicle to move
freely, where the movement of the power spring (8) reduces the
volume in the spring room (14) which causes an overpressure to
build up in the spring room (14) prevented by the internal breather
5 valve arrangement (15) and the dust plug (17) of the primary
sealing member (22), thus preventing dust and water from entering
into the spring room (14) through the dust plug (17), the seal (18),
and the O-Ring (21) and allowing the excess pressure to escape
through the internal breather valve arrangement (15) and the dust
10 plug (17);
e. releasing the brakes manually by the driver by unplugging the dust
plug (17) from the rear shell (7) if the vehicle fails or is halted due
to parking brake failure to allow access to the internal mechanisms
of the actuator and compress the power spring (8) using a wind-off
15 rod that disengages the brakes and allow the vehicle to be moved,
where after moving the vehicle, the driver forgets to reinsert the
dust plug (17), damage it, or fall out from the rear shell (7), thereby
the secondary sealing member (23) and the tertiary sealing (24)
prevent dust, mud, and water from entering into the spring room
20 (14) and internal breather valve arrangement (15), and
f. engaging the service brake (1) and the parking brake (2)
simultaneously for enhanced vehicle control during a compounding
brake application, where the air pressure depletes from the inlet
port of the parking brake (2) chamber and applies to the inlet port
25 of the service brake (1) chamber, thus allows the air pressure to
flow from the service brake (1) chamber to the spring room (14)
through the internal breather valve arrangement (15) by closing of
hole in the pusher rod assembly (12) using the plug (16) to ensures
that the air pressure dynamics remain stable and that the actuator
30 functions properly without unwanted air flow, and prevents the
entry of dust and mud water into the spring room (14) and the
28
internal breather valve arrangement (15) by the dust plug (17) of
the primary sealing member (22).
10. The method as claimed in claim 8, wherein the pressure energy is
5 converted into linear mechanical force and transfer it to a 'S'-cam through
the push rod with clevis assembly (4) and a slack adjuster, thus causing the
brake shoes to be applied when the service brake (1) is applied.
11. The method as claimed in claim 8, wherein the linear motion is converted
10 into rotary motion by using the slack adjuster to transfers the output force
to the ‘S’ cam shaft when the parking brake (2) is applied.
15
Dated this 20th day of January 2025 Kalyanchand Jhabakh (IN/PA-830)
Agent for applicant.
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