FORM 2
THE PATENT ACT 1970 (as amended)
[39 OF 1970]
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
TITLE: “A TEST RIG FOR COMBINATION SWITCH”
NAME AND ADDRESS OF THE APPLICANT: TATA MOTORS LIMITED, an
Indian company having its registered office at Bombay house, 24 Homi Mody Street,
Hutatma Chowk, Mumbai 400 001, Maharashtra, INDIA.
Nationality: INDIAN
The following specification particularly describes the nature of the invention and the
manner in which it is to be performed.
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TECHANICAL FIELD
The disclosure is related to a test rig, more particularly related to an integrated test rig for
combination switch to carry out endurance test for validating the combination switch.
BACKGROUND OF THE DISCLOSURE
The combination switch includes functions of horn, Right Hand Direction Indicator (RH
DI), Neutral, Left Hand Direction Indicator (LH DI), Off, INT Wipe, Slow Wipe and Fast
Wipe. A horn pin is actuated by using timer circuit from Programmable Logic Controller
(PLC). The RH DI, Neutral and LH DI functions included in RH lever (Stalk) of
combination switch and these functions are performed by angular movement of Direction
Indicator lever of combination switch. The Off, INT wipe, slow wipe and fast wipe
functions are included in Left Hand Lever of combination switch and these functions also
performed by angular movement of wiper lever of combination switch.
In case of existing methods and systems, and in view of endurance point of view, it is
very difficult to perform all the functions of combination switch having two different
levers in opposite (180) directions with single drive arrangement and single controller
circuit and maintaining the vehicle angle.
The endurance testing for each of the above function was performed separately, and is
carried out one after another using single lever. Thus, the test rig has disadvantage of
removing lever from assembly of the combination switch.
Further, the existing methods have limitations such as testing only one single lever at a
time without considering vehicle mounting condition (angle) while simulating the
endurance test. As single lever is putting for the test, there is limitation to apply the
maximum load onto the horn pin. Also, possibility of errors / mistake in capturing the
failure of the combination switches are there, no contact bounce is captured and no
intermittent missing of contact captured. Further, possibility of error in counting of
number of endurance cycles may occur as it counts the operation of drives and not of
actual function of the combination switch. Skilled manpower is required to perform,
monitor, and record the test results.
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Further, three operators are required for three months for completing the test for three
samples. As there was an arrangement to fit single lever of combination switch for
endurance test, the time required is three times more to validate the three samples.
For example, for conducting the test for a combination switch, the following tests are
conducted individually.
a) Wiper Lever:
Test Condition: 4 functions; 30000 Cycles/sample
Rig Capacity: 2590cycles/day/sample
Hence 32 days required for three samples
b) Light Lever:
Test condition: 3 functions; 200000 Cycles/sample
Rig Capacity: 7200 Cycles/day/sample
Hence 90 days required for 3 samples
c) Horn Contact:
Test Condition: 500000 cycles
Rig Capacity: 20000 Cycles/day/sample
Hence 75 days required for 3 samples
As the existing test system is not having any fault detection circuitry, some electrical
failure like delay in contact & intermittently missing of contact which are so difficult to
observe were not captured. Also, test rig, power supply, controller and load bank were
placed at different places on the table or on ground and occupy more ground space. The
test rig is not possible to test at other than ambient temperature and also, the existing test
rig also lacking in model compatibility.
OBJECTS OF THE DISCLOSURE
One object of the disclosure is to obviate drawbacks of existing methods and systems.
One object of the disclosure is to provide a test rig which is capable of simulating vehicle
condition and conducts endurance test of maximum number of functions of combination
switch simultaneously.
One object of the disclosure is to validate the component for the targeted endurance
cycles under criterion of customer usage and provide the method of failure simulation
which improves the product life.
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STATEMENT OF THE DISCLOSURE
Accordingly, the present disclosure is related to a test rig for a combination switch,
comprising a rack configured into plurality of vertical compartments and a platform at its
base; pair of Guide channels on either sides of a first compartment; a slotted lever
slidably connected to the Guide channels and is suspended to be displaced from one
position to other position; a linear drive provided at the Guide channels for displacing the
slotted lever horizontally; a mounting arrangement comprising plurality of support plates
connected with a supporting rods in the first compartment for mounting combination
switches on the support plates for testing; a second compartment located above the first
compartment, comprising a power supply unit and a PLC; a third compartment located
above the second compartment, comprising a counter, plurality of fault detectors, and
plurality of load banks; wherein the combination switch comprising Left Hand Lever and
Right Hand Lever are placed into the slotted lever for displacement for a predetermined
number of cycles for testing.
SUMMARY OF THE DISCLOSURE
The shortcomings of the prior art are overcome and additional advantages are provided
through the present disclosure. Additional features and advantages are realized through
the techniques of the present disclosure. Other embodiments and aspects of the disclosure
are described in detail herein and are considered a part of the claimed disclosure.
In one embodiment of the disclosure, a test rig for a combination switch is provided. The
test rig comprises a rack configured into plurality of vertical compartments and a platform
at its base. The compartments are configured into first compartment, a second
compartment located above the first compartment and a third compartment located above
the second compartment. A pair of Guide channels is provided on either sides of a first
compartment and a slotted lever slidably connected to the Guide channels, and is
suspended to be displaced from one position to other position on the guide channels. A
linear drive is provided at the Guide channels for displacing the slotted lever horizontally.
A mounting arrangement is provided at the first compartment. The mounting arrangement
comprises plurality of mounting plates connected with a vertical screw studs in the first
compartment for mounting combination switches for testing. The second compartment
located above the first compartment comprises a power supply unit and a PLC. The third
compartment located above the second compartment comprises a counter, plurality of
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fault detectors, and plurality of load banks. The combination switch comprising Left
Hand Lever and Right Hand Lever are placed into the slotted lever for displacement for
predetermined cycles for testing.
In one embodiment, the Guide channels are provided with positional sensors for locating
real-time position of the levers of the combination switches during testing.
In one embodiment, the test rig comprises a contact ring made of steering wheel fixed on
a horn pin to adjust force on the horn pin during testing.
In one embodiment, the PLC comprises a counter for counting number of cycles tested
separately for the horn, Right Hand Lever and Left Hand Lever.
In one embodiment, the test rig further comprise a fault detect circuitry to detect electrical
faults.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended
claims. The disclosure itself, however, as well as a preferred mode of use, further
objectives and advantages thereof, will best be understood by reference to the following
detailed description of an illustrative embodiment when read in conjunction with the
accompanying figures. One or more embodiments are now described, by way of example
only, with reference to the accompanying figures wherein like reference numerals
represent like elements and in which:
Fig. 1 shows the schematic diagram of the test rig according to present disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only. One
skilled in the art will readily recognize from the following description that alternative
embodiments of the structures and methods illustrated herein may be employed without
departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
In the following detailed description, reference is made to the accompanying figures,
which form a part hereof. In the figures, similar symbols typically identify similar
components, unless context dictates otherwise. The illustrative embodiments described in
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the detailed description, and figures are not meant to be limiting. Other embodiments may
be utilized, and other changes may be made, without departing from the spirit or scope of
the subject matter presented herein. It will be readily understood that the aspects of the
present disclosure, as generally described herein, and illustrated in the figures, can be
arranged, substituted, combined, and designed in a wide variety of different
configurations, all of which are explicitly contemplated and make part of this disclosure.
Referral numerals
Referral numeral Description
1 Test rig
2 Combination switch
2a Left Hand Lever
2b Right Hand Lever
3 Platform
4 Guide channel of linear drive
5 First compartment
6 Slotted lever
6a Slot in the slotted lever
7 Linear drive
8 Mounting arrangement
9 Mounting plates
10 Vertical screw studs
11 Second compartment
12 Power supply unit
13 Programmable Logic Controller (PLC)
14 Third compartment
15 Counter
16 Fault detector
17 Load bank and function indicators
18a-18h Positional sensor
19 Contact ring
20 Steering wheel
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21 Horn pin
22 Horn
23 Vertical column
24 Horizontal bars
25 Relay unit
Referring now to the drawings/figures wherein the showings are for the purpose of
illustrating a preferred embodiment of the invention only, and not for the purpose of
limiting the same.
Fig. 1 shows the schematic diagram of the test rig (1) used for testing combination switch
(2). The combination switch (2) comprises two levers on its either sides, a Left Hand
Lever (2a) and a Right Hand Lever (2b). The Left Hand Lever (2a) is used for wiping arm
functioning and the Right Hand Lever (2b) is used for direction indication and head light
activations. Both the Right Hand Lever (2b) and the Left Hand Lever (2a) are subjected to
angular movements for functioning and are tested for predetermined number of
operations.
Further, the test rig (1) comprises a mounting arrangement (8) comprises plurality of
mounting plates (9) stacked one above the other using vertical screw studs (10) and a
vertical column (23) at its middle for mounting the combinations switches (2). The space
between the mounting plates (9) is used for mounting the combination switches (2) and is
held using the vertical column (23). Pressure is applied onto horn (22) of using a horn pin
(21) located at the vertical column (23). The pressure can be varied using the horn pin
(21).
The test rig (1) comprises a rack configured into plurality of vertical compartments and a
platform (3) at its base. The rack is metallic type tubular or metallic square tube is used
for structural rigidity with less space structure having three vertical compartments such as
first compartment located at base of the test rig (1), a second compartment (11) of the test
rig (1) is above the first compartment (5). The second compartment (11) comprises power
supply unit (12) for supplying power to electrical components of the test rig (1) such as
fault detectors (16), counter (15), load bank and function indicators (17), and
Programmable Logic Controller (PLC) (13), and a third compartment (14) comprises
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electrical panel comprising the fault detectors (16), electro-mechanical counter (15) and
load bank & function indicators (17). The electrical components present in the third
compartment (14) is supplied with power by a power supply unit (12) located in the
second compartment (11).
As an example, the test rig (1) can carry out endurance test for two combination switches
(2) which are fixed to the mounting arrangement (8) one above another in such a way that
Left Hand Lever (2a) and Right Hand lever (2b) of both the combination switches (2) are
aligned vertically. A pair of Guide channels (4) is mounted on either sides of a first
compartment (5). A slotted lever (6) slidably connected to the guide channels (4) of
linear drive (7). The slotted lever (6) can be made of materials selected from a group
comprising rubber, metal and is hinged on the guide channels (4) and is free to slide along
the guide channels (4) by the linear drive (5). The slot (6a) of the slotted lever (6)
accommodates the levers (2a, 2b) of the combination switch (2) during endurance testing.
The first compartment (5) comprises position sensors (18a-18c) mounted onto horizontal
bars (24) located below the guide channels (4) such that the freely suspended bottom
portion of the slotted lever (6) is positioned at front of the position sensors (18a-18h) for
locating the slotted lever (6) at various positions. The linear drives (5) are mounted above
the guide channels (4) for driving or displacing the slotted lever (6) along the guide
channels (4). The similar arrangement of guide channels (4), linear drive (5) and
horizontal bars (18d-18h) are located on other side of the test rig (1) for carrying out
testing of the combination switches (2) simultaneously.
The test rig (1) further comprises a mounting arrangement (8). The mounting arrangement
(8) comprising plurality of mounting plates (9) connected with vertical screw studs (10) at
corners of the mounting plates (9) and a vertical column (23) for mounting the
combination switches (2). The mounting arrangement (8) is placed in first compartment
(5) of the test rig (1) and is located in such a way that the combination switches (2) used
for testing purpose is angularly mounted which is same as mounting of the combination
switches (2) in a vehicle. The levers (2a, 2b) of the combination switches (2) are inserted
into slots (6a) of the slotted levers (6) on either side of the test rig (1). Thus, the mounting
of combination switches (2) using the mounting arrangement (8) has a advantage of
conducting tests for all the testing elements (Left Hand Lever, Right Hand lever and Horn
Pin) of the combination switches (2). The rack of the test rig (1) is further characterized
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into a second compartment (11) located above the first compartment (5). The second
compartment (11) comprises a power supply unit (12), Relay unit (25) which is attached
to PLC (13) and a Programmable Logic Controller (PLC) (13). The PLC (13) also
includes counter (15) for counting the number of cycles separately for horn pin (22),
wiper function and Direction Indicator function. In one embodiment, the PLC comprises a
data memory to facilitate decision making. The PLC (13) operates the linear drive (5) for
conducting the endurance test of the combination switches (2) using various programs.
The power supply unit (12) is used to supply to electrical components of the test rig (1)
and the relay unit (25) is to supply power for the DC linear drives (5). The test rig (1) at
its top comprises a third compartment (14) located above the second compartment (11).
The third compartment (14) comprises an electrical panel comprising a counter (15),
plurality of fault detectors (16), and plurality of load banks (17). In one embodiment, as
the test rig comprises the failure detectors, it can detect and display failure of intermittent
of contact & missing of contact.
The horizontal bars (24) of the right hand side of the test rig (1) is mounted at
base/platform (3) of the test rig (1) and the horizontal bars (24) of the left hand side of the
test rig (1) is mounted at predetermined height from the platform (3). Thus, the mounting
of the combination switches (2) in the test rig (1) is angularly mounted and is according to
real time mounting of the combination switches (2) in the vehicle. The test rig (1)
according to present disclosure is having advantageous compared to prior art test rigs as
the mounting of the combination switches (2) is according to mounting as carried out in
the vehicle. Thus, the test rig (1) simulates the vehicle condition by conducting maximum
number of functions of combination switch (2) simultaneously.
In one embodiment, the test rig (1) can be accommodated with fixing more than two
mounting arrangement (8) for accommodating a more sample of the combination
switches (2) for testing. This can be achieved by varying the dimensions and other
fixtures of the first compartment (5).
A contact ring (19), for example, a copper ring of steering wheel is fixed on a horn pin
(21), contact ring (19) of copper plate is fitted below the mounting plate (9) of
combination switch, and horn pin (21) is a part of combination switch (2) which is used
for switching of horn function. Horn pin (21) is spring loaded, to make contact of horn
pin (21) with the contact ring (19), sufficient force on the horn pin (21) needs to be
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applied, which can be adjusted by adjusting the position of the mounting plate (9) of
combination switch (2) to adjust force on the horn pin (21). Thus, the test for horn (22) is
conducted for horn pin (21) which is switching with contact ring (19) by applying
pressure onto the horn (22) using the horn pin (21).
Various control programs are used for operation of RH lever (2b), the LH lever (2a) and
the horn pin (21) from a single Programmable Logic Controller (13). By using PLC,
various programs can be controlled (& not operate), it depends on the I/O ports, timers &
counters available in PLC. For this test rig, three programs are controlled by PLC, first for
DC drive which is used for operation of LH lever of combination switch, second program
for DC drive which is used to operate the RH lever of combination switch and third
program is used to make & break operation (electrically) of horn pin with contact ring)
The load function indicators are used for each function of the combination switch (2) is a
lamp. A fault detect circuitry/detector (16) is used to detect the electrical faults like delay
in contacts & intermittent missing of contacts, in case of any fault, fault detect indicator
gets signal from fault detect circuitry.
Following is the sequence of operation. One endurance cycle of Direction Indicator lever
and Wiper lever of combination switch comprises selector stack movement as follows:
Table 1 illustrates Direction Indicator selectors stack rotation and movement.
Sl.
No.
Selector Stack rotation Movement
1 OFF RH DI Angular
2 RH DI OFF Angular
3 OFF LH DI Angular
4 LH DI OFF Angular
Table 1
The above table 1 illustrates that the movement of both LH and RH levers are angular.
Table 2 illustrates Wiper function selectors stack rotation and movement.
Sr.
No.
Selector Stack rotation Movement
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1 OFF INT Wipe Angular
2 INT Wipe Slow Wipe Angular
3 Slow Wipe Fast Wipe Angular
4 Fast Wipe Slow Wipe Angular
5 Slow Wipe INT Wipe Angular
6 INT Wipe OFF Angular
Table 2
The above table 2 illustrates that the LH lever rotation is angular during its functioning
for wiper action.
Following tables summarizes condition of limit switches at each function of Direction
Indicator Lever.
Step-1: Initial / Neutral Position
Limit
switches
Position 18a 18b 18c
Status Open Closed Open
Functions
Name LH DI OFF RH DI
Status Off On Off
Table 3
Step-2: Right Hand Direction Indicator position
Limit
switches
Position 18a 18b 18c
Status Open Open Closed
Functions
Name LH DI OFF RH DI
Status Off Off On
Table 4
Step-3: LH DI Position
Limit
switches
Position 18a 18b 18c
Status Closed Open Open
Functions
Name LH DI OFF RH DI
Status On Off Off
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Table 5
Following tables summarizes the condition of limit switches at each function of Wiper
Lever.
Step-4: Initial/OFF Position
Limit
switches
Position 18d 18e 18f 18g
Status Closed Open Open Open
Functions
Name OFF INT Wipe Slow Wipe Fast Wipe
Status On Off Off Off
Table 6
Step-5: INT Wipe Position
Limit
switches
Position 18d 18e 18f 18g
Status Open Closed Open Open
Functions
Name OFF INT Wipe Slow Wipe Fast Wipe
Status Off On Off Off
Table 7
Step-6: Slow Wipe Position
Limit
switches
Position 18d 18e 18f 18g
Status Open Open Closed Open
Functions
Name OFF INT Wipe Slow Wipe Fast Wipe
Status Off Off On Off
Table 8
Step-7: Fast Wipe Position
Limit
switches
Position 18d 18e 18f 18g
Status Open Open Open Closed
Functions
Name OFF INT Wipe Slow Wipe Fast Wipe
Status Off Off Off On
Table 9
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Advantages:
In one embodiment, the endurance test conducted using the test rig as disclosed in the
present disclosure is carried out on combination switch Direction Indicator, Wiper, and
Horn function can be done simultaneously as in vehicle conditions. Three samples with
all the above functions tested at the same time as in vehicle condition.
In one embodiment, automation of test rig permits to test the combination switch at
maximum specified forces (testing at worst condition).
In one embodiment, test rig can possibly be placed in test chamber at 85ºC with 90%
relative humidity and also possible at -20ºC.
In one embodiment, during the testing of the combination switches, it is easy to capture
the contact bounce in sec., because PLC scans time in millisecond.
In one embodiment, endurance test done on complete assembled sample and hence cross
effects are also known during final performance.
In one embodiment, the test rig provides early feedback in case of failure for taking
corrective action.
In one embodiment, optimization of skilled manpower and reduction in man hours
achieved. Testing time has come down to 33% as 3 functions can be tested
simultaneously. Development time of component reduced.
In one embodiment, use of inbuilt Counter feature of the PLC for counting the endurance
cycle for each function separately has eliminated the possibility of counting error, also
resulting in saving of manpower.
In one embodiment, the test rig can provide quick, fairly accurate results and require no
special testing skills and/or high investments. Thus, overhead cost of testing is effectively
reduced.
In one embodiment, the test rig as disclosed in the present disclosure can be utilized for
performing endurance test on various vehicles’ combination switch.
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Equivalents
With respect to the use of substantially any plural and/or singular terms herein, those
having skill in the art can translate from the plural to the singular and/or from the singular
to the plural as is appropriate to the context and/or application. The various
singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and
especially in the appended claims (e.g., bodies of the appended claims) are generally
intended as "open" terms (e.g., the term "including" should be interpreted as "including
but not limited to," the term "having" should be interpreted as "having at least," the term
"includes" should be interpreted as "includes but is not limited to," etc.). It will be further
understood by those within the art that if a specific number of an introduced claim
recitation is intended, such an intent will be explicitly recited in the claim, and in the
absence of such recitation no such intent is present. For example, as an aid to
understanding, the following appended claims may contain usage of the introductory
phrases "at least one" and "one or more" to introduce claim recitations. However, the use
of such phrases should not be construed to imply that the introduction of a claim
recitation by the indefinite articles "a" or "an" limits any particular claim containing such
introduced claim recitation to inventions containing only one such recitation, even when
the same claim includes the introductory phrases "one or more" or "at least one" and
indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted
to mean "at least one" or "one or more"); the same holds true for the use of definite
articles used to introduce claim recitations. In addition, even if a specific number of an
introduced claim recitation is explicitly recited, those skilled in the art will recognize that
such recitation should typically be interpreted to mean at least the recited number (e.g.,
the bare recitation of "two recitations," without other modifiers, typically means at least
two recitations, or two or more recitations). Furthermore, in those instances where a
convention analogous to "at least one of A, B, and C, etc." is used, in general such a
construction is intended in the sense one having skill in the art would understand the
convention (e.g., "a system having at least one of A, B, and C" would include but not be
limited to systems that have A alone, B alone, C alone, A and B together, A and C
together, B and C together, and/or A, B, and C together, etc.). In those instances where a
convention analogous to "at least one of A, B, or C, etc." is used, in general such a
construction is intended in the sense one having skill in the art would understand the
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convention (e.g., "a system having at least one of A, B, or C" would include but not be
limited to systems that have A alone, B alone, C alone, A and B together, A and C
together, B and C together, and/or A, B, and C together, etc.). It will be further
understood by those within the art that virtually any disjunctive word and/or phrase
presenting two or more alternative terms, whether in the description, claims, or drawings,
should be understood to contemplate the possibilities of including one of the terms, either
of the terms, or both terms. For example, the phrase "A or B" will be understood to
include the possibilities of "A" or "B" or "A and B."
While various aspects and embodiments have been disclosed herein, other aspects and
embodiments will be apparent to those skilled in the art. The various aspects and
embodiments disclosed herein are for purposes of illustration and are not intended to be
limiting, with the true scope and spirit being indicated by the following claims.
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We claim:
1. A test rig (1) for a combination switch (2), comprising:
a rack configured into plurality of vertical compartments and a platform (3) at its
base;
pair of Guide channels (4) on either sides of a first compartment (5);
a slotted lever (6) slidably connected to the Guide channels (4) and is suspended
to be displaced from one position to other position;
a linear drive (7) provided at the Guide channels (4) for displacing the slotted
lever (6) horizontally;
a mounting arrangement (8) comprising plurality of support plates (9) connected
with a supporting rods (10) in the first compartment (5) for mounting combination
switches (2) on the support plates (9) for testing;
a second compartment (11) located above the first compartment (5), comprising a
power supply unit (12) and a Programmable Logic Controller (PLC) (13);
a third compartment (14) located above the second compartment (11), comprising
a counter (15), plurality of fault detectors (16), and plurality of load banks (17);
wherein the combination switches (2) comprising Left Hand Lever (2a) and Right
Hand Lever (2b) and are placed into the slotted lever (6) for displacement for a
predetermined cycles for testing.
2. The test rig (1) as claimed in claim 1, wherein the Guide channels (4) mounted
towards to platform (3) are provided with positional sensors (18) for locating realtime
position of the levers (2a, 2b) of the combination switches (2) during testing.
3. The test rig (1) as claimed in claim 1, wherein the test rig (1) comprises a contact ring
(19) made of steering wheel (20) fixed on a horn pin (21) to adjust force on the horn
pin (21) during testing.
4. The test rig (1) as claimed in claim 1, wherein the PLC (13) comprises a counter (15)
for counting number of cycles tested separately for the horn (22), Right Hand Lever
(2b) and Left Hand Lever (2a).
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5. The test rig (1) as claimed in claim 1, further comprise a fault detector (16) to detect
electrical faults.
6. A test rig for a combination switch is substantially as herein above described and as
illustrated in accompanying drawings.