Description:DIAPHRAGM SEALING AND LOCKING UNIT FOR DOUBLE
DIAPHRAGM SPRING BRAKE ACTUATOR AND OPERATION
METHOD THEREOF
FIELD OF INVENTION
5 The present invention relates to the field of mechanics. Particularly, the present
invention relates to the double diaphragm of the spring brake actuator in
commercial vehicles. More particularly, the present invention relates to the locking
and sealing unit of a diaphragm in the double diaphragm spring brake actuator.
BACKGROUND OF THE INVENTION
10 Brake actuators and diaphragm actuators play a key role in the braking system.
Their purpose is to convert the pressure exerted on the brake pedal into braking
force. Wheel brake actuators, for instance in drum brakes, transfer the pressure built
up by the master brake actuator in the braking system to the brake shoes. In disc
brakes, diaphragm actuators ensure the pressure generated acts on the brake caliper,
15 thereby pressing the brake pads against the brake discs.
The double diaphragm spring brake actuator is used for generating the input force
required for the service brake and the parking brake.
When the driver applies a parking brake, air pressure in the parking brake chamber
drops as the brakes are applied. This causes the flexible diaphragm to be upward
20 into the service brake chamber to S-cam/Disc Brake.
Once the parking brakes are released, the diaphragm flexes back into place. The
ports reopen, allowing air to flow between parking chambers again. For the
effective functioning of the application and release of brakes, air leakage from the
chamber must be prevented by proper locking and sealing of the diaphragm. In both
25 parking brake apply & release condition, breathing happens through internal
breather valve.
3
There are few reports available in the literature about the existence of various
diaphragm locking and sealing units of double diaphragm spring brake actuator.
CN2839053 discloses a utility model which relates to a double-diaphragm type
spring brake cylinder assembly which is composed of a front shell component, a
5 back shell spinning component, a push rod component, a clamping hoop
component, diaphragms, a return spring, a dustproof cap, screws, a dustproof cover,
a locking nut, a connecting fork, a spring washer, a locking nut, a special-shaped
rubber sealing ring, a snap ring, a thread sleeve and a sealing ring. The utility model
is characterized in that the diaphragm an arranged in a back shell and the diaphragm
10 b arranged in the front shell present a cylinder shape, and the outer side of each of
two O-shaped rubber sealing rings in the position of the middle shell inner hole of
a middle shell component is provided with a nylon ring; the back shell component
is also provided with a filter core with a glue surface, which is pasted to the inner
side of a spring support and the front shell and the back shell are matched with the
15 axial geometric shape of the diaphragm b and the diaphragm a. The utility model
increases travel range, and the rubber diaphragms present a cylinder shape, which
reduces the loss of a lateral force generated by air pressure and makes an output
force stable and a characteristic curve smooth; meanwhile, two nylon guide
bearings are additionally provided, which reduces friction resistance and the loss of
20 an output force of a spring brake chamber; because of an air filtering device, the
corrosion of an energy storage spring and the abrasion of the rubber diaphragms are
reduced and long service life is prolonged.
CN209638287 discloses a utility model which relates to a double-diaphragm disc
type spring brake chamber capable of automatically loading parking brake. The
25 structure comprises a front cover assembly, a middle body assembly and a rear
cover assembly, a push rod disc cavity, a service brake cavity, a parking brake front
cavity and a parking brake rear cavity are formed, a tappet assembly is installed in
the parking brake rear cavity, the tappet assembly comprises a release disc
assembly, a tappet and a tappet supporting assembly, the release disc assembly is
30 installed at one end of the tappet and connected with a rear cavity leather film, and
4
the tappet supporting assembly is installed at the other end of the tappet; the release
disc assembly comprises a release disc and a guide sleeve, the release disc is
installed on the guide sleeve, the tappet is sleeved with the guide sleeve, and an
automatic combining mechanism is further installed on the guide sleeve. An air
5 outlet is formed in the side end surface of the front cover assembly; an air outlet
pipeline is installed on the upper end face of the rear cover assembly. The utility
model ensures that the strong spring is in a non-compression state when the parking
brake is released before loading, relieves the influence of fatigue on the service life,
is convenient to transport, and can ensure that the dustproof and waterproof effects
10 are achieved in the air chamber of the brake cavity.
Moreover, from the above cited literature it is clear that the effective diaphragm
locking and sealing is yet to be accomplished. Furthermore, the above-mentioned
prior arts don’t provide sufficient details about the locking and sealing mechanism
and they also involve multiple parts which make the system more complex and does
15 not prove to be cost effective. Hence, there exists an urgent need in the state of art
to develop and design a novel a diaphragm locking and sealing unit for double
diaphragm spring brake actuator.
To overcome the existing drawbacks and issues one solution is the introduction of
diaphragm locking and sealing unit for the double diaphragm spring brake actuator.
20 This invention relates to the traditional knowledge of mechanical engineering,
compliant mechanisms, and structural engineering. However, the present invention
mainly focuses on effective locking and sealing of the diaphragm for double
diaphragm spring brake actuator for commercial vehicles.
OBJECTIVES OF THE INVENTION
25 The principal objective of the present invention is to develop a diaphragm locking
unit.
Another objective of the present invention is to develop a diaphragm sealing unit.
5
Further another objective of the present invention is to develop a diaphragm threelayer locking and three-layer sealing unit for a double diaphragm spring brake
actuator.
SUMMARY OF THE INVENTION
5 The present invention discloses a diaphragm sealing and locking unit in double
diaphragm spring brake actuator (100), comprising: a parking brake (2) comprising
a rear shell (7), a power spring (8), a spring guide (9), an adaptor (10), a diaphragm
(11), a pusher rod assembly (12), a flange (13), a spring room (14), and an internal
breather arrangement (15), diaphragm (11) comprising two or more diaphragm
10 primary beads (11d, 11g) and diaphragm secondary beads (11f, 11c); a service
brake (1) comprising a diaphragm (3), a push rod with clevis assembly (4), a nonpressure plate assembly (5), and a return spring (6), wherein the adaptor (10), the
diaphragm (11), and the pusher rod assembly (12) are engaged together as a locking
and sealing unit; locking unit comprises a tight fit of an adaptor stopper surface
15 (10f) with a pusher rod assembly-stopper face (12f) configured to squeeze
diaphragm secondary bead 1 (11c), diaphragm primary bead 1 (11d), diaphragm
secondary bead 2 (11f) and diaphragm primary bead 2 (11g); a diaphragm wing
(11a) configured to be locked in an adaptor groove (10a); the diaphragm (11)
configured to be assembled in an adaptor stem-diaphragm guide face (10b) through
20 a diaphragm hole (11b); the adaptor stem outer surface (10c) and the diaphragm
(11) configured to be locked inside the rod of the pusher rod assembly inner surface
(12a); a concave profile of the pusher rod assembly (12d) configured to be locked
in a diaphragm projection (11e) to hold the diaphragm tightly, wherein sealing unit
comprises the diaphragm wing (11a) and the adaptor groove (10a), the concave
25 profile of the pusher rod assembly (12d) and the diaphragm projection (11e)
configured to have a volume filling in between them, diaphragm primary bead 1
(11d) and diaphragm primary bead 2 (11g) configured to be sealed between an
adaptor rim- primary sealing zone (10e) and pusher rod assembly-primary sealing
zone (12c), diaphragm secondary bead 1 (11c) and diaphragm secondary bead 2
6
(11f) configured to be sealed between an adaptor groove-secondary sealing zone
(10d) and pusher rod assembly -secondary sealing zone (12b) to arrest the air leak.
In one aspect of the present invention, the adaptor stopper surface (10f) and pusher
rod assembly -stopper face (12f) configured to squeeze diaphragm secondary bead
5 1 (11c), diaphragm primary bead 1 (11d), diaphragm secondary bead 2 (11f) and
diaphragm primary bead 2 (11g), diaphragm hole (11b) locked in between adaptor
stem-diaphragm guide face (10b) & pusher rod assembly inner surface (12a) forms
the first layer of locking of diaphragm
In one aspect of the present invention, the diaphragm wing (11a) configured to be
10 locked in the adaptor groove (10a) forms the second layer of locking of diaphragm.
In one aspect of the present invention, the concave profile of the pusher rod
assembly (12d) configured to be locked in a diaphragm projection (11e) forms the
third layer of locking of diaphragm.
In another aspect of the present invention, the diaphragm wing (11a) and the adaptor
15 groove (10a), the concave profile of the pusher rod assembly (12d) and the
diaphragm projection (11e) configured to have a volume filling in between them
forms the first layer of sealing of diaphragm.
In one aspect of the present invention, the diaphragm primary bead 1 (11d) and
diaphragm primary bead 2 (11g) configured to be sealed between an adaptor rim20 primary sealing zone (10e) and pusher rod assembly-primary sealing zone (12c)
forms the second layer of sealing of diaphragm.
In one aspect of the present invention, the diaphragm secondary bead 1 (11c) and
diaphragm secondary bead 2 (11f) are configured to be sealed between an adaptor
groove-secondary sealing zone (10d) and Pusher rod assembly -secondary sealing
25 zone (12b) forms the third layer of sealing of diaphragm.
7
In another aspect of the present invention, the adaptor (10), the diaphragm (11), and
the pusher rod assembly (12) are configured to be engaged by a press fit, threaded
joint, riveting, pasting, gluing, cotter joint, coupling or spinning.
In one aspect of the present invention, the adaptor (10) profile is manufactured by
5 processes comprising machining, forming, forging and the like.
In one aspect of the present invention, the pusher rod assembly (12) profile is
manufactured by processes comprising machining, forming, forging, welding and
the like.
In one aspect of the present invention, the diaphragm primary beads and diaphragm
10 secondary beads profile is selected from circle, taper, D shape, square and
trapezoid.
In one aspect of the present invention, the number of diaphragm primary beads
(11d, 11g) ranges from 1 to 6.
In one aspect of the present invention, the number of diaphragm secondary beads
15 (11c, 11f) ranges from 1 to 6.
In one aspect of the present invention, the radius of diaphragm primary beads and
diaphragm secondary beads ranges from 0.1 to 5.0 mm, height of diaphragm
primary beads and diaphragm secondary beadsranges from 0.1 to 8.0 mm and width
of diaphragm primary beads and diaphragm secondary beads ranges from 0.1 to 8.0
20 mm.
The method of operation of the diaphragm sealing and locking unit in double
diaphragm spring brake actuator (100), comprising steps of:
a. engaging adaptor (10), the diaphragm (11), and the pusher rod assembly
(12) together as a locking and sealing unit;
25 b. applying assembly load/torque on the adaptor stopper surface (10f) and
the pusher rod assembly-stopper face (12f) to squeeze diaphragm
secondary bead 1 (11c), diaphragm primary bead 1 (11d), diaphragm
8
secondary bead 2 (11f) and diaphragm primary bead 2 (11g) forming
the first layer of locking of diaphragm;
c. locking the diaphragm wing (11a) in the adaptor groove (10a) forming
the second layer of locking of diaphragm;
5 d. locking the concave profile of the pusher rod assembly (12d) in the
diaphragm projection (11e) forming the third layer of locking of
diaphragm;
e. volume filling in between the diaphragm wing (11a) and the adaptor
groove (10a), the concave profile of the pusher rod assembly (12d) and
10 the diaphragm projection (11e) forming the first layer of sealing of
diaphragm;
f. sealing between the diaphragm primary bead 1 (11d), diaphragm
primary bead 2 (11g), the adaptor rim- primary sealing zone (10e) and
pusher rod assembly-primary sealing zone (12c) forming the second
15 layer of sealing of diaphragm, and
g. sealing between the diaphragm secondary bead 1 (11c), diaphragm
secondary bead 2 (11f), the adaptor groove-secondary sealing zone
(10d) and pusher rod assembly -secondary sealing zone (12b) forming
the third layer of sealing of diaphragm.
20 BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts the double diaphragm spring brake actuator of the present
invention.
Figure 2 depicts the diaphragm locking and sealing unit (100) of the present
invention.
25 Figure 3 depicts the Parking brake apply condition of the present invention.
Figure 4 depicts the Parking brake release condition of the present invention.
Figure 5 depicts the parts of adaptor of the present invention.
Figure 6 depicts the pusher rod assembly of the present invention.
Figure 7a depicts the bottom view of the diaphragm of the present invention.
30 Figure 7b depicts the top view of the diaphragm of the present invention.
9
Figure 8a depicts the diaphragm profile arrangement of the present invention.
Figure 8b depicts the enlarged view of the diaphragm profile arrangement of the
present invention as shown in figure 8a.
Figure 9 depicts the enlarged view of the diaphragm locking and sealing unit (100)
5 of the present invention.
REFERENCE NUMERALS:
Table 1: Reference numerals for “DIAPHRAGM SEALING AND LOCKING
UNIT FOR DOUBLE DIAPHRAGM SPRING BRAKE ACTUATOR AND
10 OPERATION METHOD THEREOF” of the present invention:
S.NO PART NAME PART NUMEBR
1 Service Brake (1)
2 Parking Brake (2)
3 Diaphragm - A (3)
4 Push Rod with Clevis Assembly (4)
5 Non-Pressure Plate Assembly (5)
6 Return Spring (6)
7 Rear Shell (7)
8 Power Spring (8)
9 Spring Guide (9)
10 Adaptor (10)
11 Diaphragm (11)
12 Pusher rod assembly (12)
13 Flange (13)
14 Spring room (14)
15 Internal breather Unit (15)
16 Adaptor groove (10a)
17 Adaptor stem-diaphragm guide face (10b)
18 Adaptor stem outer surface (10c)
10
19 Adaptor groove-secondary sealing zone (10d)
20 Adaptor rim- Primary sealing zone (10e)
21 Adaptor stopper surface (10f)
22 Adaptor outer profile-Guide face (10g)
22 Diaphragm wing (11a)
23 Diaphragm hole (11b)
24 Diaphragm secondary bead 1 (11c)
25 Diaphragm primary bead 1 (11d)
26 Diaphragm projection (11e)
27 Diaphragm secondary bead 2 (11f)
28 Diaphragm primary bead 2 (11g)
29 Pusher rod assembly inner surface (12a)
30 Pusher rod assembly -secondary sealing
zone
(12b)
31 Pusher rod assembly-Primary sealing zone (12c)
32 Concave profile of the pusher rod assembly (12d)
33 Pusher rod assembly -Stopper face (12f)
34 Pusher rod assembly -butting face (12e)
DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by “DIAPHRAGM SEALING AND
LOCKING UNIT FOR DOUBLE DIAPHRAGM SPRING BRAKE
5 ACTUATOR AND OPERATION METHOD THEREOF”, succinctly fulfils
the abovementioned need(s) in the art. The present invention has objective(s)
arising as a result of the above-mentioned need(s), said objective(s) being
enumerated below. In 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
10 objective(s) are not exhaustive of the present invention in its entirety, and are
enclosed solely for the purpose of illustration. Further, the present invention
11
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 therefore encompasses also, any
5 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 spirit or essential attributes
thereof.
Throughout this specification, the use of the word "comprise" and variations such
10 as "comprises" and "comprising" may imply the inclusion of an element or elements
not specifically recited.
The present invention relates to the locking and sealing unit of a diaphragm in the
double diaphragm spring brake actuator.
The Double Diaphragm Spring Brake Actuator is a device used to convert
15 pneumatic pressure energy into mechanical output force. It consists of both Service
brake and Parking brake components.
Service Brake:
The Service brake portion of the actuator includes a diaphragm, push rod with clevis
assembly, non-pressure plate assembly, and a return spring.
20 Parking Brake:
The Parking brake section of the actuator consists of a rear shell, power spring,
spring guide, adaptor, diaphragm, pusher rod assembly, flange, spring room, and
internal breather unit.
The adaptor (10) of the present invention comprises of an adaptor groove (10a), an
25 adaptor stem-diaphragm guide face (10b), an adaptor stem outer surface (10c), an
adaptor groove-secondary sealing zone (10d), an adaptor rim- primary sealing zone
12
(10e), an adaptor stopper surface (10f) and an adaptor outer profile-guide face
(10g).
The diaphragm (11) of the present invention comprises of a diaphragm wing (11a),
a diaphragm hole (11b), a diaphragm secondary bead 1 (11c), a diaphragm primary
5 bead 1 (11d), a diaphragm projection (11e), a diaphragm secondary bead 2 (11f),
and a diaphragm primary bead 2 (11g).
The pusher rod assembly (12) of the present invention comprises of a pusher rod
assembly inner surface (12a), a pusher rod assembly -secondary sealing zone (12b),
a pusher rod assembly-primary sealing zone (12c), a concave profile of the pusher
10 rod assembly (12d), a pusher rod assembly -stopper face (12f) and Pusher rod
assembly -butting face (12e).
In reference to Figure 5 and Figure 9, the adaptor (10) comprises of adaptor side 1
and adaptor side 2. The adaptor side 1 of the adaptor profile arrangement comprises
of an outer rim referred to as the adaptor rim- primary sealing zone (10e), followed
15 by the adaptor groove (10a), followed by the adaptor groove-secondary sealing
zone (10d), the adaptor stem forms the centremost part of the adaptor (10) with the
adaptor stem outer surface (10c), the adaptor stem-diaphragm guide face (10b)
found in between adaptor groove-secondary sealing zone (10d) and the adaptor
stem outer surface (10c). The adaptor side 2 of the adaptor profile comprises of the
20 adaptor stopper surface (10f) and the adaptor outer profile-guide face (10g).
In reference to Figure 7a, Figure 7b, Figure 8a, Figure 8b and Figure 9, the
diaphragm (11) comprises of diaphragm side 1 and diaphragm side 2. The
diaphragm side 1 of the diaphragm profile comprises of a diaphragm hole (11b) in
the centre part of the diaphragm followed by the diaphragm wing (11a), the
25 diaphragm secondary bead 1 (11c) present in between diaphragm hole (11b) and
the diaphragm wing (11a) while the diaphragm primary bead 1 (11d) is present on
the other side of the diaphragm wing (11a). The diaphragm side 2 of the diaphragm
profile comprises of diaphragm secondary bead 2 (11f) which lies close to the
13
diaphragm hole (11b) followed by the diaphragm primary bead 2 (11g) followed by
the diaphragm projection (11e).
In reference to Figure 6 and Figure 9, the pusher rod assembly (12) comprises of
pusher rod assembly inner surface (12a), the diaphragm face of the pusher rod
5 assembly comprises of a pusher rod assembly -secondary sealing zone (12b), a
pusher rod assembly-primary sealing zone (12c), a concave profile of the pusher
rod assembly (12d), pusher rod assembly -butting face (12e) while the pusher rod
assembly -stopper face (12f) is face away from the diaphragm.
The present invention related to the diaphragm locking and sealing unit which
10 consists of diaphragm (11) assembled in the groove of adaptor (10). Adaptor (10)
& diaphragm (11) interference/threaded is locked in the rod of pusher rod assembly
(12). Adaptor (10) is guided in spring guide (9) groove. It prevents air leak entry to
the spring room, which helps to improve the life of the double diaphragm spring
brake actuator. The diaphragm sealing & locking unit helps to flow the breather air
15 for both parking brake apply & release condition.
The diaphragm (11) is fitted inside the adaptor (10) of the double diaphragm spring
brake actuator. Diaphragm wing (11a) is locked in adaptor groove (10a) which
helps in sealing to tightly hold the diaphragm. Diaphragm hole (11b) is assembled
in adaptor stem-diaphragm guide face (10b). The adaptor stem outer surface (10c)
20 & diaphragm (11) interference/threaded is locked inside the rod of the pusher rod
assembly inner surface (12a). The concave profile of the pusher rod assembly (12d)
is tightly locked in the diaphragm projection (11e). During assembly condition high
load/torque is applied on both adaptor stopper surface (10f) & pusher rod assembly
-stopper face (12f) to squeeze the diaphragm. This squeeze helps to arrest the air
25 leak.
The adaptor (10) profile is manufactured by processes comprising machining,
forming, forging and the like.
14
The pusher rod assembly (12) profile is manufactured by processes comprising
machining, forming, forging, welding and the like.
The diaphragm primary beads and diaphragm secondary beads profile is selected
from circle, taper, D shape, square and trapezoid.
5 The number of diaphragm primary beads (11d, 11g) ranges from 1 to 6.
The number of diaphragm secondary beads (11c, 11f) ranges from 1 to 6.
The radius of diaphragm primary beads and diaphragm secondary beads ranges
from 0.1 to 5.0 mm, height of diaphragm primary beads and diaphragm secondary
beads ranges from 0.1 to 8.0 mm and width of diaphragm primary beads and
10 diaphragm secondary beads ranges from 0.1 to 8.0 mm.
Diaphragm locking arrangement:
1. First layer locking: Assembly load/torque is applied on adaptor stopper
surface (10f) and pusher rod assembly -stopper face (12f) to get the better
squeeze on diaphragm secondary bead 1 (11c), diaphragm primary bead 1
15 (11d), diaphragm secondary bead 2 (11f) and diaphragm primary bead 2
(11g), diaphragm hole (11b) locked in between adaptor stem-diaphragm
guide face (10b) & pusher rod assembly inner surface (12a).
2. Second layer locking: The diaphragm wing (11a) is tightly locked in the
adaptor groove (10a).
20 3. Third layer locking: The concave profile of the pusher rod assembly (12d)
is tightly locked in the diaphragm projection (11e).
This three-layer locking unit helps to tightly hold the diaphragm in both apply &
release condition of the parking brake as shown in Figures 3 & 4.
Diaphragm sealing arrangement:
15
1. First layer sealing: Volume filling happens in between diaphragm wing
(11a) & adaptor groove (10a), the concave profile of the pusher rod
assembly (12d) & diaphragm projection (11e).
2. Second layer sealing: The diaphragm primary bead 1 (11d) and diaphragm
5 primary bead 2 (11g) & seal between adaptor rim- Primary sealing zone
(10e) & pusher rod assembly-primary sealing zone (12c).
3. Third layer sealing: The diaphragm secondary bead 1 (11c) and diaphragm
secondary bead 2 (11f) & seal between adaptor groove-secondary sealing
zone (10d) & pusher rod assembly -secondary sealing zone (12b).
10 This three-layer sealing/locking arrangement help to arrest the air leak for both
brakes apply & release condition as shown in Figures 3 & 4.
The adaptor stopper surface (10f) properly guides in spring guide groove (9). Both
male & female guide profile help to guide the diaphragm for both brake apply and
release condition. In this clearance between adaptor outer profile-guide face (10g)
15 & spring guide (9) helps to provide articulation.
Application of the present invention:
Service brake working: During normal vehicle condition, parking brake power
spring (8) is compressed/caged by means of air pressure applied in port 12
(Figure1). During service brake (1) application, pressurized air is supplied from
20 reservoir to port 11, which acts on the Diaphragm - A (3), the pressure energy is
converted into linear mechanical force and transferred to ‘S’ cam through push rod
with clevis assembly (4) & slack adjuster. Hence brake is applied.
Parking brake application: During parking brake (2) application, air pressure from
the port 12 will be depleted to atmosphere. This air pressure release allows power
25 spring (8), spring guide (9), adaptor (10), diaphragm (11) & pusher rod assembly
(12) start to expand and spring force is transferred to slack adjuster via push rod
with clevis assembly (4). Slack adjuster converts linear motion to rotary motion &
transfer output force to ‘S’ cam shaft/ Disc and brake is applied.
16
During parking brake (2) application, air pressure from port 12 will be exhausted
through graduated hand control valve. So heavy coil spring (8) starts to expand and
apply the parking brake. Due to the spring (8), spring guide (9), adaptor (10)
diaphragm (11) and pusher rod assembly (12) movement, the diaphragm (11)
5 interference/threaded locked inside the adaptor (10) & pusher rod assembly (12).
Adaptor (10) & pusher rod assembly (12) properly guided in spring guide (9) &
flange (13). This helps to properly guide to move the diaphragm (11) & pusher rod
assembly (12) to apply the brake. The heavy coil spring (8), spring guide (9) &
diaphragm (11) movement, volume increase happens in spring room (14). This
10 causes vacuum pressure in spring room (14). Atmospheric air from the port 11
flows to the spring room (14) through the hole provided in the rod of pusher rod
assembly (12), internal breather valve (15), diaphragm (11) adaptor (10) and spring
guide (9). This vacuum in spring room (14) is depleted.
Parking brake Release: Parking brake (2) release (Figure4), Air pressure is applied
15 through Port 12 through Graduated Hand control valve. So Heavy coil spring (8)
start to be compressed, and parking brake (2) will be released. Due to the spring
(8), spring guide (9), adaptor (10), diaphragm (11), and pusher rod assembly (12)
movement, the diaphragm (11) interference/ threaded locked inside the adaptor (10)
& pusher rod assembly (12). Adaptor (10) & pusher rod assembly (12) properly
20 guided in spring guide (9) & flange (13). This helps to properly guide to move the
diaphragm (11) & pusher rod assembly (12) to release the brake. The diaphragm
(11) rubber volume filled inside the adaptor (10) & pusher rod assembly (12), the
diaphragm (11) tightly squeeze & sealed both adaptor (10) & pusher rod assembly
(12) helps to prevent the air leak.
25 The adaptor (10), the diaphragm (11), and the pusher rod assembly (12) are
configured to be engaged by a press fit, threaded joint, riveting, pasting, gluing,
cotter joint, coupling or spinning.
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
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.
5
10
15
20

17 , Claims:WE CLAIM:
1. A diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100), comprising:
a parking brake (2) comprising a rear shell (7), a power spring (8), a spring
5 guide (9), an adaptor (10), a diaphragm (11), a pusher rod assembly (12), a
flange (13), a spring room (14), and an internal breather arrangement (15),
diaphragm (11) comprising 1 to 6 diaphragm primary beads (11d, 11g) and
diaphragm secondary beads (11f, 11c),
10 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),
wherein the adaptor (10), the diaphragm (11), and the pusher rod assembly
(12) are engaged together as a locking and sealing unit;
15 locking unit comprises a tight fit of an adaptor stopper surface (10f) with a
pusher rod assembly-stopper face (12f) configured to squeeze diaphragm
secondary bead 1 (11c), diaphragm primary bead 1 (11d), diaphragm
secondary bead 2 (11f) and diaphragm primary bead 2 (11g); a diaphragm
wing (11a) configured to be locked in an adaptor groove (10a); the
20 diaphragm (11) configured to be assembled in an adaptor stem-diaphragm
guide face (10b) through a diaphragm hole (11b); the adaptor stem outer
surface (10c) and the diaphragm (11) configured to be locked inside the rod
of the pusher rod assembly inner surface (12a); a concave profile of the
pusher rod assembly (12d) configured to be locked in a diaphragm
25 projection (11e) to hold the diaphragm tightly.
wherein sealing unit comprises the diaphragm wing (11a) and the adaptor
groove (10a), the concave profile of the pusher rod assembly (12d) and the
diaphragm projection (11e) configured to have a volume filling in between
them, diaphragm primary bead 1 (11d) and diaphragm primary bead 2 (11g)
19
configured to be sealed between an adaptor rim- primary sealing zone (10e)
and pusher rod assembly-primary sealing zone (12c), diaphragm secondary
bead 1 (11c) and diaphragm secondary bead 2 (11f) configured to be sealed
between an adaptor groove-secondary sealing zone (10d) and pusher rod
5 assembly -secondary sealing zone (12b) to arrest the air leak.
2. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the adaptor stopper surface (10f)
and pusher rod assembly -stopper face (12f) configured to squeeze diaphragm
10 secondary bead 1 (11c), diaphragm primary bead 1 (11d), diaphragm secondary
bead 2 (11f) and diaphragm primary bead 2 (11g), diaphragm hole (11b) locked
in between adaptor stem-diaphragm guide face (10b) & pusher rod assembly
inner surface (12a) forms the first layer of locking of diaphragm.
15 3. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the diaphragm wing (11a)
configured to be locked in the adaptor groove (10a) forms the second layer of
locking of diaphragm.
20 4. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the concave profile of the pusher
rod assembly (12d) configured to be locked in a diaphragm projection (11e)
forms the third layer of locking of diaphragm.
25 5. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the diaphragm wing (11a) and the
adaptor groove (10a), the concave profile of the pusher rod assembly (12d) and
the diaphragm projection (11e) configured to have a volume filling in between
them forms the first layer of sealing of diaphragm.
30
6. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the diaphragm primary bead 1
20
(11d) and diaphragm primary bead 2 (11g) configured to be sealed between an
adaptor rim- primary sealing zone (10e) and pusher rod assembly-primary
sealing zone (12c) forms the second layer of sealing of diaphragm.
5 7. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the diaphragm secondary bead 1
(11c) and diaphragm secondary bead 2 (11f) are configured to be sealed
between an adaptor groove-secondary sealing zone (10d) and Pusher rod
assembly -secondary sealing zone (12b) forms the third layer of sealing of
10 diaphragm.
8. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the adaptor (10), the diaphragm
(11), and the pusher rod assembly (12) are configured to be engaged by a press
15 fit, threaded joint, riveting, pasting, gluing, cotter joint, coupling or spinning.
9. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the adaptor (10) profile is
manufactured by processes comprising machining, forming, forging and the
20 like.
10. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the pusher rod assembly (12)
profile is manufactured by processes comprising machining, forming, forging,
25 welding and the like.
11. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the diaphragm primary beads and
diaphragm secondary beads profile is selected from circle, taper, D shape,
30 square and trapezoid.
21
12. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the number of diaphragm primary
beads (11d, 11g) ranges from 1 to 6.
5 13. The diaphragm sealing and locking unit in double diaphragm spring brake
actuator (100) as claimed in claim 1, wherein the number of diaphragm
secondary beads (11c, 11f) ranges from 1 to 6.
14. The diaphragm sealing and locking unit in double diaphragm spring brake
10 actuator (100) as claimed in claim 1, wherein the radius of diaphragm primary
beads and diaphragm secondary beads ranges from 0.1 to 5.0 mm, height of
diaphragm primary beads and diaphragm secondary beads ranges from 0.1 to
8.0 mm and width of diaphragm primary beads and diaphragm secondary beads
ranges from 0.1 to 8.0 mm,
15
15. The method of operation of the diaphragm sealing and locking unit in double
diaphragm spring brake actuator (100) as claimed in claim 1, comprising steps
of:
a. engaging adaptor (10), the diaphragm (11), and the pusher rod
20 assembly (12) together as a locking and sealing unit;
b. applying assembly load/torque on the adaptor stopper surface
(10f) and the pusher rod assembly-stopper face (12f) to squeeze
diaphragm secondary bead 1 (11c), diaphragm primary bead 1
(11d), diaphragm secondary bead 2 (11f) and diaphragm primary
25 bead 2 (11g) forming the first layer of locking of diaphragm;
c. locking the diaphragm wing (11a) in the adaptor groove (10a)
forming the second layer of locking of diaphragm;
d. locking the concave profile of the pusher rod assembly (12d) in
the diaphragm projection (11e) forming the third layer of locking
30 of diaphragm;
e. volume filling in between the diaphragm wing (11a) and the
adaptor groove (10a), the concave profile of the pusher rod
22
assembly (12d) and the diaphragm projection (11e) forming the
first layer of sealing of diaphragm;
f. sealing between the diaphragm primary bead 1 (11d), diaphragm
primary bead 2 (11g), the adaptor rim- primary sealing zone
5 (10e) and pusher rod assembly-primary sealing zone (12c)
forming the second layer of sealing of diaphragm, and
g. sealing between the diaphragm secondary bead 1 (11c),
diaphragm secondary bead 2 (11f), the adaptor groovesecondary sealing zone (10d) and pusher rod assembly -
10 secondary sealing zone (12b) forming the third layer of sealing
of diaphragm.
15
Dated this 20th day of June 2024
-SDKalyanchand Jhabakh (IN/PA-830)
20 Agent for Applicant
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