The present disclosure relates to “Electronics based parking brake switch” for a vehicle
5 which gives signals to the Electronic control unit (ECU).
BACKGROUND
An electronic-parking brake (EPB) also known as an electric-park brake is an
electronically controlled parking brake, whereby the driver activates the holding mechanism
10 with a button and the brake pads are electrically applied to the rear wheels. This is accomplished
by an electronic control unit (ECU) and an actuator mechanism (e.g. electric motor).
In case of the traditional handbrake, a lever tensions a cable when it’s pulled up. That
cable squeezes the car’s rear brake pads or shoes onto the brake discs or drums holding the car
15 firmly in place. Some cars have a separate disc and pads on the rear axle specifically for the
handbrake. Electronic parking brakes work on the same basis but use electric motors to achieve
the effect. Press or pull the button and motors on the rear brakes press the pads onto the discs.
Electronic parking brake system also works on the same principle of mechanical hand
20 brake system, but instead of a mechanical level and cable, it is done through a switch, which
activates the electric motor and it allows the rear brake shoes or pads to get into contact with the
rear drum or disc brake of the vehicle.
The electronic parking brakes are more consistent as compared to the manual parking
25 brakes. The same employ an electric-motor, which performs all the actions and is more
consistent braking engagement that is connected to the ECU.
The electronic parking brake is more reliable because it offers more safety and
consistency, which is also required in emergency-braking. Unlike a traditional handbrake, the
30 electronic parking brake need not require adjustment of cable. It offers more space in the cabin
of the vehicle, which allows carmakers to design an interior that in turn looks a bit more
uncluttered and organized. The electronic parking brake is the future because it keeps the vehicle
in control under emergency braking, which is also a good-safety measure.
2
The parking brake with auto-hold function is effective especially if one is driving on a
steep uphill and there is a risk of rolling backwards due to insufficient torque. However during
steep curves and roads, heavy trucks and cars do use the handbrake while driving slowly up the
hill. The accidental slip when one is waiting at a signal can be easily avoided if the handbrake is
5 effectively used.
However, fact remains that existing electronic switches for braking in vehicle are
complex in make and high on cost due to complex assembly, not only the manufacturing costs
are high, but also the switch is difficult to operate for a relatively untrained passenger or
10 relatively a new driver.
There lies at least a need for an economical electronic switch for braking that is low on
manufacturing-cost, easy to operate and durable.
15 SUMMARY
This summary is provided to introduce a selection of concepts in a simplified format that
is further described in the detailed description of the invention. This summary is not intended to
identify key or essential inventive concepts of the claimed subject matter, nor is it intended for
determining the scope of the claimed subject matter.
20
An electronic switch for vehicle comprises a toggle switch disposed at a centre console
for actuating a brake. The Toggle switch defines at-least two states comprising a brake apply
state, and a brake release state. A push button switch is disposed at the centre console and
configured for controlling an automatic hold position of a brake. A PCB is connected to the
25 toggle switch and/or the push-button switch, such that the PCB comprises a connector for
interfacing the toggle switch and the push button switch with electrical power and an embedded
electronic unit configured to generate control signals in the vehicle for brake apply, brake release
and auto hold function within the vehicle.
30 The present subject matter’s electronic parking brake is a function offering the driver
increased comfort and convenience. In addition, as the hand lever is not used, car manufacturers
have more freedom of choice as to where they site the operating parts within the car. Electronic
handbrakes are more reliable than a mechanical system, free up space for storage in the centre
console and remove complications from the driving process.
35
3
The present subject matter’s designed switch comprises toggle/ push-pull type button for
apply and release function and push return type button for auto hold function. The switch
comprises electronic PCB having electronics components and mechanical arrangements to pushpull the button. This design is economical as compared to the other electronics based design with
5 same functionality.
The Electronic signal as generated depends on the switch press condition and is sent to
the connector of the PCB for further forwarding to the electronic control unit.
10 To further clarify the advantages and features of the present invention, a more particular
description of the invention will be rendered by reference to specific embodiments thereof,
which is illustrated in the appended drawings. It is appreciated that these drawings depict only
typical embodiments of the invention and are therefore not to be considered limiting of its scope.
The invention will be described and explained with additional specificity and detail with the
15 accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become
better understood when the following detailed description is read with reference to the
20 accompanying drawings in which like characters represent like parts throughout the drawings,
wherein:
Figure 1 illustrates complete block diagram of Electronics based Parking Brake Switch
system, according to an embodiment of the present subject matter;
25
Figure 2 illustrates architecture of the Electronics based Parking Brake Switch, according
to an embodiment of the present subject matter;
Figure 3 illustrates mechanical design of Electronics based Parking Brake Switch system,
30 according to an embodiment of the present subject matter;
Figure 4 illustrates mechanical design of Electronics based Parking Brake Switch system
connector side view, according to an embodiment of the present subject matter;
4
Figure 5 illustrates transparent view of Electronics based Parking Brake Switch design for
better understanding of push switch arrangement, according to an embodiment of the present
subject matter;
5 Figure 6 illustrates PCB part of Electronics based Parking Brake Switch, according to an
embodiment of the present subject matter; and
Figure 7 illustrates the circuit diagram of Electronics based Parking Brake Switch,
according to an embodiment of the present subject matter.
10
In terms of the construction of the device, one or more components of the device may have
been represented in the drawings by conventional symbols, and the drawings may show only
those specific details that are pertinent to understanding the embodiments of the present
invention so as not to obscure the drawings with details that will be readily apparent to those of
15 ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION OF FIGURES
For the purpose of promoting an understanding of the principles of the invention, reference
20 will now be made to the embodiment illustrated in the drawings and specific language will be
used to describe the same. It will nevertheless be understood that no limitation of the scope of
the invention is thereby intended, such alterations and further modifications in the illustrated
system, and such further applications of the principles of the invention as illustrated therein
being contemplated as would normally occur to one skilled in the art to which the invention
25 relates. Unless otherwise defined, all technical and scientific terms used herein have the same
meaning as commonly understood by one of ordinary skilled in the art to which this invention
belongs. The system, methods, and examples provided herein are illustrative only and not
intended to be limiting.
30 Embodiments of the present invention will be described below in detail with reference to
the accompanying drawings.
The present disclosure relates to Electronics based parking brake switch employed in
vehicle. On pressing, the switch triggers the current and voltage based signals to the ECU. The
5
present disclosure offers electronics based parking brake system having unique signal flow
based on a bi-directional flow of signal or unidirectional flow driven by a pre-configured logic.

Figure 1 illustrates a perspective view of an assembly comprising Electronic parking
5 brake switch 101 for a vehicle (not shown), according to the embodiments of the present subject
matter. The switch 101 draws power from an ECU 104 via a power line 102 supplying rail to rail
voltage (12V). The actuation of a plurality of control-buttons with respect to electronic parking
brake-switch 101 issues and receives the signal via signal-lines 103. The ECU 104 finally
generates the control signal (e.g. via a power MOSFET) to the braking system 105 of the vehicle
10 (not shown). As may be understood, the braking system may be a combination of an electric
motor and the brakes, such that the motor may be driven by the power MOSFET.
Figure 2 illustrates an architecture of Electronic parking brake switch 101 provided with
the Printed Circuit Board (PCB) 201. The PCB 201 is provided with a connector 202 that
15 receives the power-lines 203 and the signal-lines 204 (for example supported in another
connector to be coupled with the connector 202) for the switch 101. The power signal lines 203
may be 12V DC (i.e. rail to rail voltage) and Ground (0V) voltage. The signal-lines 204 are may
be current and voltage-signals which are connected to ECU 104 with the help of connector 202.
20 Figure 3 illustrates a schematic-view of the Electronic parking brake switch 101. The
switch 101 comprises a toggle switch 301 disposed for example at a centre console for actuating
the brake. The toggle switch 301 defines at-least two states defined by a brake-apply state, and a
brake-release state. The toggle switch 301 corresponds to a push-pull switch park button 301
which is used for apply and release the parking-brake.
25
A push-button switch 302 is also disposed at the centre console and configured for
controlling an automatic hold-position of the brake. Such auto hold button 302 function using
push return type button is used largely in inclined surface and hill-area. The park-button 301 and
auto hold button 302 are fitted with the base body 304. The park button 301 and auto hold 302
30 are covered with the bezel 303. The base body 304 may be further accommodated in the centerconsole of the car to support the switch 101 within the car.
Figure 4 illustrates a connector side view of the Electronic parking brake switch 101. The
present embodiment may use a 12-pin male or female type connector 401 which is the part of the
35 base-body 304. The connector 401 receives the power-lines 203 and the signal-lines 204 (for the
6
switch 101. The power signal lines 203 may be 12V DC (i.e. rail to rail voltage) and Ground
(0V) voltage. The signal-lines 204 are may be current and voltage-signals.
Figure 5 illustrates the transparent view of Electronics based parking brake-switch101.
5 The push return type switch 501 is used for release-condition and corresponds to one state of the
toggle-switch as provided in preceding description. The push-return type switch 502 may be
used for apply condition and corresponds to another state of the toggle-switch as provided in
preceding description. The push-return type switch 503 may be used for auto-hold function and
correspond to a push-button switch as provided in the preceding description.
10
These switches 501, 502, 503 comprise various sub-switches (shown in Fig. 6 and Fig. 7)
that are placed on the Printed Circuit Board (PCB) 504. More specifically, the PCB 504 supports
the toggle switch and/or the push-button switch, and the connector 401. The connector 401
interfaces the toggle switch and the push button switch with electrical-power and an embedded
15 electronic unit configured to generate control-signals in the vehicle. The switch-press
mechanism may be performed with the help of the pusher 505 which may act as a motion
receiving and transmitting means for the sub-switches 501, 502, 503.
Figure 6 illustrates the schematics view of the Printed Circuit Board (PCB) 504 with the
20 switch press combination for the apply condition 601. Switch press combination for release
condition 602 and auto hold function switch 603. In the combination 601 & 602 two pair of
switches are same and one pair of switch different. The apply condition comprises three subswitches SW1, SW3, and SW2. The release condition 602 comprises sub-switches as SW1,
SW3, and SW4. The auto hold function switch 603 comprises the subs-switch SW5.
25
As a part of logical operation, the present subject matter’s circuit functionality for the
Electronic parking brake switch 101 has been referred in the forthcoming figure 7. The present
circuit comprises a unique functionality of Bi-directional signal flow or blockage, a
unidirectional flow or blockage depending on the type of switch press condition (i.e. apply,
30 release, neutral). There are three conditions Neutral, Apply and Release.
Figure 7 illustrates the circuit diagram of apply and release function of Electronics based
parking brake 101. The assembly of the plurality of sub-switches in Fig. 6 further comprises a
plurality of varistors to protecting from voltage spikes, a plurality of diodes for current
7
directionality, a plurality of transistors for enabling electronic switching of the sub-switches,
and a resistance to limit the current in circuit and forward-reverse biasing of transistor.
In an example, the circuit has the pin terminal SIG 1 701, SIG4 702, SIG 2 703, SIG 3 704
5 which can be used as input and output port. Circuit having varistors 705, 706,707,708 are
provided to protect the circuit from voltage spikes. Circuit consists of diodes 711, 712 for
current directionality. Circuit having resistance 713, 714 are configured to limit the current in
circuit. Circuit comprises resistance 717 for biasing of transistor Q1 721 and resistances 718 for
biasing of transistor Q2 722. Circuit comprises Ground reference voltage GND
10 719,720,723,724,725,726. Circuit also comprises push return switches 709, 710 which are in
pair and push return switch 715, 716 to control the switching of transistor Q1 721 and Q2 722.
The toggle switch is a push pull switch comprising an assembly of a plurality of subswitches (SW1, SW2, SW3, SW4) and signal pins (SIG 1, 2, 3, 4). The assembly of the plurality
15 of sub-switches (SW1, SW2, SW3, SW4) further comprises a collinearly arranged set of
switches for ease of simultaneous operation, said switches defined as at least one of: a first set
of push type switch SW1, SW2, SW3, and a second set of push type switches SW1, SW4, SW3
offset from the first set of switches.
20 In operation, the toggle switch defines a neutral state defined as:
an open-state of a plurality of sub-switches (S1, S2, S3, S4),
a unidirectional current state between a first pair of signal pins (SIG2, SIG3), and
a unidirectional current state between a second pair of signal pins (SIG1, SIG4).
25 More specifically, in neutral condition there is no any pressing of switch. All switches 709,
710, 715,716 are in open condition, i.e. SW1=SW2=SW3=SW4=0
If voltage signal is applied at pin SIG3 704 it will reach pin SIG2 703 and if voltage signal
is applied at pin SIG2 703 it will not reach at pin SIG3 704. Circuit current flow may be
30 represented as follows:
SIG3  SIG2; SIG2 X SIG3
If voltage signal is applied at pin SIG1 701 it will reach pin SIG4 702 and if voltage
signal is applied at pin SIG4 702 it will not reach at pin SIG1 701. Circuit current flow is:
35 SIG1  SIG4; SIG4 X SIG1
8
In another operation, the toggle switch defines a neutral state Apply condition. The brake
apply state is defined as:
an open state of at least one sub-switch (S4) and closed state of a plurality of sub5 switches (SW1, SW2, SW3);
a bidirectional current state between a first pair of signal pins (SIG 2, SIG 3); and
a unidirectional current state between a second pair of signal pins (SIG1, SIG4).
Specifically, in Apply condition there are three switches pressed. Switches 709, 710, 716
10 are pressed and 715 is in open condition, i.e. SW1=SW2=SW3=1; SW4=0. If voltage signal is
applied at pin SIG3 704 it will reach pin SIG2 703 and if voltage signal is applied at pin SIG2
703 it will reach at pin SIG3 704. Circuit current flow is:
SIG3  SIG2; SIG2  SIG3
15 If voltage signal is applied at pin SIG4 702 it will reach at pin SIG1 701 and if voltage
signal is applied at pin SIG1 701 it will not reach pin SIG4 702. Circuit current flow is:
SIG4  SIG1; SIG1 X SIG4
In another operation, the toggle switch defines a brake release state as:
20 an open state of at least one sub-switch (SW2) and a closed state of a plurality of subswitches (SW1, SW4, SW3);
a bidirectional current state between a second pair of signal pins (SIG1, SIG4); and
a unidirectional current state between a first pair of signal pins (SIG2, SIG3).
25 More specially, in Release condition there are three switches pressed. Switches 709, 710,
715 are pressed and 716 is in open condition, i.e. SW1=SW3=SW4=1; SW2=0
If voltage signal is applied at pin SIG3 704 it will not reach pin SIG2 703 and if voltage
signal is applied at pin SIG2 703 it will reach at pin SIG3 704. Circuit flow will be from:
30 SIG3 X SIG2; SIG2  SIG3
If voltage signal is applied at pin SIG1 701 it will reach pin SIG4 702 and if voltage
signal is applied at pin SIG4 702 it will reach at pin SIG1 701. Circuit current flow is:
SIG1  SIG4; SIG4  SIG1
9
The present subject matter’s electronic parking brake is a function offering the driver
increased comfort and convenience. In addition, as the hand lever is not used, car manufacturers
have more freedom of choice as to where they site the operating parts within the car. Electronic
5 handbrakes are more reliable than a mechanical system, free up space for storage in the centre
console and remove complications from the driving process.
The present subject matter’s designed switch comprises toggle/ push-pull type button for
apply and release function and push return type button for auto hold function. The switch
10 comprises electronic PCB having electronics components and mechanical arrangements to pushpull the button. This design is economical as compared to the other electronics based design with
same functionality.
While specific language has been used to describe the disclosure, any limitations arising
15 on account of the same are not intended. As would be apparent to a person in the art, various
working modifications may be made to the method in order to implement the inventive concept
as taught herein.
The drawings and the forgoing description give examples of embodiments. Those skilled
20 in the art will appreciate that one or more of the described elements may well be combined into a
single functional element. Alternatively, certain elements may be split into multiple functional
elements. Elements from one embodiment may be added to another embodiment. For example,
orders of processes described herein may be changed and are not limited to the manner described
herein.
25
Moreover, the actions of any flow diagram need not be implemented in the order shown;
nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on
other acts may be performed in parallel with the other acts. The scope of embodiments is by no
means limited by these specific examples. Numerous variations, whether explicitly given in the
30 specification or not, such as differences in structure, dimension, and use of material, are
possible. The scope of embodiments is at least as broad as given by the following claims.
Benefits, other advantages, and solutions to problems have been described above with
regard to specific embodiments. However, the benefits, advantages, solutions to the problem and
35 any component(s) that may cause any benefit, advantage, or solution to occur or become more
10
pronounced are not to be construed as a critical, required, or essential feature or component of
any or all the claims.

We Claim:
1. An electronic switch (101) for vehicle comprising:
a toggle switch (301) for actuating a brake, said toggle switch (301) defining at least two
5 states comprising:

a brake apply state;

a brake release state;
10
a push button switch (302) configured for controlling an automatic hold position of a
brake; and
a PCB (504) connected to the toggle switch (301) and/or the push-button switch (302)
15 and comprising a connector (401) for interfacing the toggle switch (301) and the push button
switch (302) with electrical power and an embedded electronic unit (ECU) configured to
generate control signals in the vehicle.
2. The switch (101) as claimed in claim 1, wherein the toggle switch (301) is a push-pull switch
20 comprising an assembly of a plurality of sub-switches (SW1, SW2, SW3, SW4) and signal pins
(SIG 1, 2, 3, 4).
3. The switch (101) as claimed in claim 2, wherein the brake apply state is defined as:
an open state of at least one sub-switch (S4) and closed state of a plurality of sub25 switches (SW1, SW2, SW3)
a bidirectional current state between a first pair of signal pins (SIG 2, SIG 3); and
a unidirectional current state between a second pair of signal pins (SIG1, SIG4).
4. The switch (101) as claimed in claim 2, wherein the brake release state is defined as:
30
an open state of at least one sub-switch (SW2) and a closed state of a plurality of subswitches (SW1, SW4, SW3) a bidirectional current state between a second pair of signal pins
(SIG1, SIG4); and
a unidirectional current state between a first pair of signal pins (SIG2, SIG3).
12
5. The switch (101) as claimed in claim 2, wherein the toggle switch (301) defines a neutral
state defined as:
an open-state of a plurality of sub-switches (SW1, SW2, SW3, SW4);
5 unidirectional current state between a first pair of signal pins (SIG2, SIG3); and
a unidirectional current state between a second pair of signal pins (SIG1, SIG4).
6. The switch as claimed in claim 2, wherein the assembly of the plurality of sub-switches
(SW1, SW2, SW3, SW4) further comprises:
10 a plurality of varistors to protecting from voltage spikes;
a plurality of diodes for current directionality;
a plurality of transistors for enabling electronic switching of the sub-switches (SW1,
SW2, SW3, SW4); and
a resistance to limit the current in circuit and forward-reverse biasing of transistor.
15
7. The switch as claimed in claim 2, wherein the assembly of the plurality of sub-switches
(SW1, SW2, SW3, SW4) further comprises a collinearly arranged set of switches for ease of
simultaneous operation, said switches defined as at least one of:
a first set of push type switch SW1, SW2, SW3; and
20 a second set of push type switches SW1, SW4, SW3 offset from the first set of switches
SW1, SW2, SW3.
8. The switch as claimed in claim 1, wherein the connector (401) is a 12-pin male or female
type connector 401 and receives power-lines 203 and signal-lines 204.