DESC:BACKGROUND

The purpose of head lamp interlock / starter interlocks is to prevent inadvertent operation of starter button and operation of headlamp during undesired conditions. For example, the starter switch should not get operated while the engine is in running condition and the headlamp switch should not get operated until the engine has achieved running condition.

Head lamp control unit circuit (commonly known as HLCU) employs a relay which is energized by the charging coil (which provides RPM input) and allows the headlamp switch to function only when the RPM has reached to a certain predetermined level, i.e. it does not permit to function the head lamp switch until the engine is fired or is operating mode. This is done by connecting the headlamp switch to One position (say for example NO Position) i.e. Normally Open Position of contact of a relay which gets activated when relay coil of relay switch is energized once receiving engine RPM input from charging coil. The other position of say for example (NC position i.e. Normally Closed Position ) of the contact of the relay thus is OFF (in denergised state) once the desired RPM has reached. In other words, it is disconnected when the engine is in running condition.
Principally starter interlock works in the similar manner.

These features which provide starter interlock and head lamp interlock are provided independently (i.e. separate unit for each interlock) in a vehicle. These features are provided by using independent and separate relays and circuits and systems for both interlocks as separate unit and through using costly control mechanisms.

The other known concepts are costly, for ex BCU (Body Control Unit), ignition unit with starter interlock, separate starter interlock unit. All these are costly mechanisms are redundant very often due to duplicity.

PRIOR ARTS

There are many prior arts relating to above two which is Head Lamp interlock and Starter interlock of interlock systems of which few are given below:-
US 6024065: This invention relates to deactivating the starter relay with an ECU when an attempt is made to restart a running vehicle. The invention attempts to prevent the inadvertent restarts after the vehicle is running by using an ECU operably associated with the starter relay.

US 354039: This invention relates to preventing multiple activation of the starter. This invention relates to hindering repeat attempts to start an engine when engine fails to start on a previous actuation with a control circuit. This invention does disclose a control circuit which is “exclusively” connected only to starter motor and achieves the object by providing a predetermined time period after each starter actuation during which the starter cannot be reactuated.

US 4209816: The invention uses electronic logic to deenergise the starter relay at predetermined engine RPM and disengages the starter and allows reenergisation of starter relay when a master switch is closed and engine is not in running condition. In this invention logic circuit (38) permits energisation of the starter relay using a main relay (24) which needs to be closed and starter switch (44) is also manually closed to complete the circuit between battery (30) to starter motor. This arrangement is expensive and again is “exclusive” to starter motor interlock circuit. [Line 1-10 column 3]

JP 2003002111: This invention relates to disabling the headlamp interlock when engine RPM is below predetermined speed limit.

As such the above two circuits i.e. starter motor interlock and vehicle headlamp interlock circuits are independently managed to control and manage the starter motor interlock circuit and vehicle head lamp interlock circuit in all of the prior arts. Further these prior are complicated and have costly control mechanisms.

Hence there is a need of a composite and a compact system for integrating the two control circuits and which shall also be more reliable and cost effective.

OBJECTIVES /PROBLEMS TO BE SOLVED:

Objective is to provide a control system which shall have a combined and interdependent starter interlock and head lamp interlock circuits which is cost effective.

Yet another objective is to provide a control system which has simple arrangement but still reliable and less bulky.

Yet another objective to provide a control system for combined starter interlock and head lamp interlock which occupies very less space and can be fitted into existing layout of vehicle.

Typically a vehicle has a starter motor operable by a relay; when an ignition switch is engaged in ‘START’ or ‘ON’ state. Typically the pressing of starter switches enables the flow the power to energise the starter relay, if the vehicle ignition switch is turned ‘ON’ for starting the vehicle. This allows the current to flow to starter motor. Typically a vehicle also has a Head lamp which is controlled by a Head Lamp interlock circuit also using a relay. The invention is novel as none of the prior art have the combination of the interlocks in a single system as disclosed herein.

The ignition and starter switch may be combined switch being activated at two different positions of the switch.

The inventive step of the invention lies in using the two interlock circuits advantageously and combinedly to form a single control system which is reliable, compact and cost effective.

Invention is related to combining the headlamp and starter interlock circuits and making a single unit.

To achieve this, the unused position of relay contact of one of the interlock circuit is used with another interlock circuit.

As one of the embodiments, the NC position of relay contact of headlamp interlock circuit which is unused (i.e. when the engine has attained a predetermined speed) may be “electrically” connected to relay contact of starter interlock , thus making a combined interlock relay for headlamp as well as starter interlock. With this arrangement, the starter interlock relay is operable till the relay contact of head lamp is at NC position, i.e., when engine is not in running condition. Whereas, when the engine RPM is detected through a logic input system , the charging coil of interlock circuit energizes the relay contact of head lamp and it achieves NO position from NC position, thereby disabling the starting interlock circuit and thereafter enabling the headlamp interlock circuit.

The invention therefore achieves the integration of two different circuits in a single system, each operating at one of the two different position of relay contact of the combined interlock relay.

Towards this, an additional output from HLCU (Head lamp control unit) to starter switch is provided.

Use of 3 pole coupler/connector for additional output to starter circuit adapted.PCB layout modified to get additional output for starter switch.

Alternatively, this could have been done by providing one additional single pole coupler but this would incur more cost and increase number connections and would require some packaging space.

In one aspect the invention discloses a control system for starter interlock and head lamp interlock of a vehicle having an engine operable with a starter motor and battery. The said control system is combined for head lamp interlock and starter interlock. It shall have plurality of circuits, say for example first circuit and second circuit, operating headlamp interlock function and starter interlock function. Each circuit comprising atleast a relay. The relay of the said first circuit having two positions of its relay contact. One position of the contact being at energized state and other position at de-energized state of the relay contact. The said first circuit and said second circuit shall be actuated with respect to energized and de-energized state of said relay contact. The energized and de-energized state of said two positions of said relay contact is based on an electronic logic input with respect to engine rpm.

In the present invention, for ease of understanding the energized position of said relay contact being termed as NO and denergised position being termed as NC position. However the modifications and variations are possible as will be understood by skilled person in the art.

In one aspect, preferably the said first circuit is actuated during the energized state of said relay contact and said second circuit being actuated during de-energized state of said relay contact.

Preferably the said first relay of said first circuit shall have a relay coil being used to energize and de-energize the said relay contact to form said NC and NO positions based on an electronic logic input system with respect to engine RPM.

Preferably, as one of the embodiments, the said first circuit comprising said first relay between said battery and said head lamp to form a Headlamp interlock circuit.

The said first circuit further comprising an ignition switch, a headlamp switch. The said ignition switch is interposed between the said battery and said first relay. The said headlamp switch is interposed between first relay and said headlamp .The first circuit gets completed at NO position of contacts which being energized through said relay coil based on an electronic logic input while the engine has attained a predefined rpm and head lamp switch is in ON condition.

This situation /condition allows headlamp switch to actuate to make headlamp in ON /OFF condition (as desired by operator) as the engine is in running condition. However this situation/condition does not allow starter switch or button to get actuated. Thus forming headlamp control circuit and starter interlock control.

The said second circuit comprising a second relay having a second relay coil and starter relay contact. The said second relay is positioned between said battery and said starter motor to form a starter interlock circuit through NC Position of the relay contacts of said first relay of said first circuit.

The said second circuit further comprising an ignition switch, a starter switch or button; the said ignition switch interposed between the said battery and said first relay. The said starter switch is interposed between first relay and said second relay . The second circuit gets completed while relay contact is in NC position and based on an electronic logic input while the engine is not in running condition and said starter switch and ignition switch are in pressed or ON condition.

This situation /condition allows starter switch to actuate starter motor to get engine in running condition. However this situation/condition does not allow headlamp switch to actuate to make headlamp in ON condition as the engine is not in running condition. Thus forming staring control circuit and headlamp interlock control.

The relays and coils of said control system are packaged in a single unit i.e. combined interlock control unit or casing. Preferably the said control system for combined starter interlock and head lamp interlock employs a three pole coupler or connector.

One pole of connector connected to battery through ignition switch and same connection inside the combined interlock control unit connected to common pole of the relay. Second and third Poles are connected to Starter motor relay & headlamp control switch and same connections inside the combined interlock control unit connected to NC & NO contacts of HLC (Head lamp Control) relay.

The said unit or casing can be connected to a frame portion of the vehicle through brackets and suitable fastening arrangements.

Preferably the location of said control system/unit could be same as that of location of starter interlock or headlamp interlock system provided in the existing vehicle. Though other locations could be considered.
In one embodiment, the invention relates to a control system preventing inadvertent operation of starter switch and also inadvertent operation of head lamp of a vehicle having an engine operable with a starter motor and battery. It is characterized in the combined head lamp and starter interlock circuits. The system has relay between said battery and said starter motor to form a starter interlock circuit through NC contacts and the said relay is also between said battery and said head lamp to form a Headlamp interlock circuit through NO contact. An ignition switch interposed in circuit in between the said battery and starter interlock circuit. A starter switch interposed in circuit with starter interlock circuit and the starter motor. A light switch in circuit with Headlamp interlock circuit and the lamp. An electronic logic for the relay which permits the relay to maintain NC state in its de-energised state, and which is energised only when said engine of the vehicle is running beyond a predetermined RPM by permitting the energisation of the coil of the relay when the starter switch is closed and when it senses an engine RPM beyond a predetermined value to changeover the relay from NC state to NO state.

In another embodiment the invention relates to a control system for starter interlock head lamp interlock of a vehicle having an engine operable with a starter motor and battery wherein said control system is combined for head lamp interlock and starter interlock and comprising plurality of circuits; each circuit comprising at least a relay; said first circuit being operable only after engine start up and another circuit being operable only during start up of engine.

In another embodiment the invention relates to control system for starter interlock and head lamp interlock wherein first and second circuits working on same input (engine rpm) and operable through NO and NC relay contacts of said first circuit ;the said first relay comprising a relay coil being energized and de-energized through an electronic logic system ;both the circuits being not functionally interdependent.

COST COMPARISON:

Approx Cost of Headlamp interlock relay working on Engine RPM input: Rs. 69/-

Approx Cost of Starter interlock relay working on Engine RPM input: Rs. 142/-

Approx cost of invented combined Head lamp and Starter interlock working on engine RPM: Rs.70/-

The Advantages of the invention commercially are many such as less cost, less no. of parts, less space, improvement in productivity and simple circuitry.

Detail Description of Invention with reference to accompanied drawings

Figures 1, 3, 4 and 5 are depicting existing or know systems.

Figures 2 and 6A to 8B are illustrating present invention.

In a typical existing system head lamp operation is interlocked with engine RPM. The head lamp switch is enabled only if engine is running and remains disabled if engine is not running. This is illustrated in fig. 1.

However in the invention the head lamp and the starter are combinedly interlocked with engine RPM. The head lamp switch (16) is enabled only if engine is running and starter switch(15) remains disabled when engine is running. The starter switch(15) is enabled while engine is not running and headlamp switch(16) remains disabled while engine is not running. Thus head lamp and the starter are interlocks are in a single system, working with engine RPM input signal. This is illustrated in fig. 2.

According to figure 2, there is provided battery (10) which is supplying power to the interlock circuits. Ignition switch (11) is electrically connected to said battery (10) and to relay contact (25) of first relay (12).The said relay (12) is comprising a relay coil (13) and a relay contact (25).The said relay contact having two positions i.e. NC and NO based on activation of said relay coil (13) with respect to an electronic logic input (14), in the said embodiment the input is through charging coil. The NO position is enegerised position of said relay contact (25) while the relay coil (13) is activated by said electronic logic input (14) based on the signal that engine has achieved a predefined rpm .In the present embodiment this signal input is through charging coil (21).

The NC position is de-energised position of said relay contact (25) while the said relay coil (13) is not activated.

The NC position of said contact (25) is making connection with lamp/light switch (16) which operates ON/OFF function of Headlamp (19).Thus when the ignition switch is (11) is in ON/pressed, engine is in running condition and when the relay contact is at NO position, (i.e. relay coil 13 is activated by said electronic logic input (14) based on the signal that engine is in running condition), the first circuit (1) is formed. The said circuit gets power to head lamp (19) when the headlamp/light switch (16) is pressed or operated to ON condition. The operation is schematically represented shown in figure 6A, the completion of first circuit is shown through arrow marks.

During this condition the second circuit for starter lock relay is not operative, the starter switch (15) is in disabled condition.

The second circuit becomes operative while the said relay coil (13)is not in energized state i.e. relay coil 13 is not activated by said electronic logic input (14) based on the signal that engine is not in running condition. During this condition, the said relay contact (25) is in NC position. The said NC position of said relay contact (25) connected to second relay coil (17) of second relay (22), the said second relay is comprising a second relay contact(18).Thus during this condition while ignition switch (11) is in ON/Pressed condition and starter switch/button (15) is operated, the said second relay (17) actuates the said second relay contact (18) .This actuation makes the circuit connected to starter motor (20),thus forming the second circuit(2) .The starter motor (20) initiates the cranking of the engine (not shown).

The operation is schematically represented shown in figure 6B, the circuit completion of the second circuit is shown through arrow marks.

During this condition the headlamp interlock circuit is not operative, the headlamp switch (16) is in disabled condition.

It can be understood from above description and figure that during this condition the first circuit for headlamp interlock is not operative.

Fig. 3 illustrates the known principle of starter interlock with engine RPM in an igniter, wherein starter switch is enabled only if engine is not running and remains disabled when engine is running. The starter relay is in the ‘OFF’ mode when the engine RPM is sufficiently in running condition.

Fig. 4 illustrates the known principle of starter interlock with engine RPM in a CDI , wherein starter switch is enabled only if engine is not running and remains disabled when engine is running. The starter relay is in the ‘OFF’ mode when the engine RPM is sufficiently in running condition.

Fig. 5 illustrates the known principle of starter interlock with engine RPM in ECU, wherein starter switch is enabled only if engine is not running and remains disabled when engine is running. The starter relay is in the ‘OFF’ mode when the engine RPM is sufficiently in running condition.

Fig. 6A the completion of first circuit is illustrated through arrow marks.

Fig. 6B the completion of the second circuit is illustrated through arrow marks.

Fig. 7 illustrates the mounting arrangement of the system according to invention. Two views are shown.

It shows a frame tube (1) of the vehicle (not shown) .The combined interlock control system enclosed in a single casing /housing (5a) forming a combined unit (5), which is connected to said frame tube by using a mounting bracket (2) .

Through the connector (3) (having 3poles) battery voltage, Starter relay & head lamp control switch are interfaced to the control unit (5).

Through the connector (4) (having 2 poles) engine rpm signal interfaces to the control unit.

A rubber damper (6) is provided at mounting location to absorb/dampen the vibration of vehicle.

Fig.8a illustrates connections of known single interlock according to prior art wherein a two pole coupler (34) is used

Fig.8b illustrates connections of combined starter and headlamp interlock according to invention wherein a three pole coupler (35) is used.

The PCB (Printed circuit board) is marked with numeral 32.Connection of 3 pole coupler (35) with said PCB is shown. Also disclosed connection of charging coil input to PCB.

The system as per the invention is designed by interconnecting the interlocks provides a high level of reliability and fail-safe operation and elimination of redundant control circuits but without affecting the system operativeness adversely thereby satisfying the need in the field of invention by providing a most advantageous system. The foregoing description of the embodiments and illustrations have been provided to illustrate and explain the principles of the invention and not to limit the invention to any specific embodiment/s. The scope of the invention is encompassed within the claims and their equivalents. ,CLAIMS:1. A control system for starter interlock and head lamp interlock of a vehicle having an engine operable with a starter motor and battery (10 )wherein said control system is combined for head lamp interlock and starter interlock and comprising plurality of circuits(1,2) operating headlamp interlock function and starter interlock function,; each circuit comprising atleast a relay (12, 22) ; said relay (12) of the said first circuit comprising two positions of its relay contact (25) ;one position being at energized state of relay contact (25) and other position at de-energized state of the relay contact(25) ; the said first circuit (1) and said second circuit (2) being actuated with respect to energized and de-energized state of said relay contact(25) ; the energized and de-energized state of said two positions of said relay contact is based on an electronic logic input (14) with respect to engine rpm.

2. A control system for starter interlock and head lamp interlock as claimed in claim 1 wherein said first circuit (1) being actuated during the energized state of said relay contact (25) and said second circuit being actuated during de-energized state of said relay contact (25).

3. A control system for starter interlock and head lamp interlock as claimed in claim 1 wherein the said first relay (12) of said first circuit (1) comprising a relay coil (13) being used to energize and de-energize the said relay contact (25) to form said two positions (NC and NO positions) based on an electronic logic input system with respect to engine RPM.

4. A control system for starter interlock and head lamp interlock as claimed in claim 1 wherein the said first circuit (1) comprising said first relay(12) between said battery(10) and said head lamp(19) to form a Headlamp control circuit and starter interlock circuit.

5. A control system for starter interlock and head lamp interlock as claimed in claim 4 wherein the said first circuit (1) further comprising an ignition switch (11) , a headlamp switch (16) ;the said ignition switch (11) interposed between the said battery(10) and said first relay (12) ; the said headlamp switch (16) is interposed between first relay(12) and said headlamp(19) ;the first circuit being gets completed at NO position of relay contacts (25) which being energized through said relay coil (13) of first circuit (1) based on an electronic logic input while the engine has attained a predefined rpm and head lamp switch 16 is actuated in ON condition.

6. A control system for starter interlock and head lamp interlock as claimed in claim 1 wherein said second circuit (2) comprising a second relay (22) having a second relay coil(17) and starter relay contact(18); the said second relay is positioned between said battery and said starter motor to form a starter control circuit and headlamp interlock circuit through de-energized state (NC Position) of the relay contact (25) of said first relay(12) of said first circuit(1).

7. A control system for starter interlock and head lamp interlock as claimed in claim 6 wherein said second circuit(2) further comprising an ignition switch(11) , a starter switch or button (15) ;the said ignition switch(11) interposed between the said battery (10) and said first relay (12) ; the said starter switch (15) is interposed between first relay (12) and said second relay(22); the second circuit gets completed while relay contact(25) is in NC position and based on an electronic logic input while the engine is not in running condition and said starter switch is in pressed or ON condition.

8. A control system for starter interlock and head lamp interlock as claimed in claim 1 further includes a three pole coupler or connector (35) in the said arrangement.

9. A control system for starter interlock and head lamp interlock as claimed in claim 1 wherein the said plurality of circuits including the said relays and coils are housed in a casing (5a) forming a combined interlock control unit (5); said casing adapted to be attached to a frame portion of the vehicle through brackets and fastening arrangement.

10. A control system for starter interlock and head lamp interlock as claimed in claim 8 and 9 one pole of connector connected to external battery through an external ignition switch and same connection inside the control unit connected to common pole of the headlamp relay; second and third Poles of said connector (35) being connected to an external starter PB switch of Starter motor relay & an external headlamp control switch respectively and same correspond connections inside the control system unit (5) connected to NC & NO contacts of HLC ( Head lamp Control) relay.

11. A control system for starter interlock and head lamp interlock as claimed in claim 9 wherein the location of said control system unit (5) could be same as that of starter interlock system or headlamp interlock system of prior art.

12. A vehicle comprising control system for starter interlock and head lamp interlock as claimed in any of the above claims.