DESC:FIELD OF INVENTION

[001] The present invention relates to a device for automatic switching of turn indicators in vehicles towing another vehicle. In particular, the present invention relates to a device automatic switching of turn indicators in a tractor towing a trailer. More particularly, the present invention relates to automatic switching of tell-tale in a towing vehicle drawing a towed vehicle.

BACKGROUND OF THE INVENTION

[002] Normally, agricultural tractors should always be equipped with full lighting systems. This is particularly important, in case of tractors drawing a trailer. So, the installation of lighting and light-signaling devices, such as turn indicators is an essential safety requirement for such agricultural tractors.

[003] Accordingly, an operating tell-tale is necessary for front and rear direction indicator lamps, if not directly visible to the driver. It could be made as visual or auditory tell-tale or both combined.

[004] In case of a visual tell-tale, it shall be a flashing light which, at least in the event of the malfunction of any of the front or rear direction indicator lamps, is either extinguished, or remains alight continuously, or it shows a noticeable change of flashing frequency thereof.

[005] In case of a fully auditory tell-tale, it shall be clearly audible and must show a marked change of frequency of auditory warnings, at least in the event of the malfunction of direction indicator lamps.

[006] If a tractor is equipped to draw or tow a trailer, it shall be fitted with a visual operational tell-tale indication for the direction indicator lamps on the trailer, unless the tell- tale of the drawing tractor allows the failure of any one of the direction indicator lamps on the tractor / trailer combination thus formed to be detected.

[007] Any visual tell-tale shall be a flashing light which flashes at 90±30 times per minute. The operation of the light-signal control shall be followed within not more than a second from the flashing of light and within not more than 1.5 second by its first extinction.

[008] If a tractor is equipped to draw a trailer, the control of the direction indicator lamps on the drawing tractor shall also operate the indicator lamps of the trailer. In the event of failure - other than short-circuit - of one direction indicator lamp, the others must continue to flash, but the frequency in this condition may be different from the prescribed frequency.

[009] It is necessary to have the Tell-tale indication of the trailer lamp in the following conditions:

a) Tractor equipped to draw a trailer shall always be fitted with a visual operational tell-tale for the direction indicator lamps on the trailer unless the tell- tale of the drawing tractor allows the failure of any one of the direction indicator lamps on the tractor / trailer combination thus formed to be detected, and

b) The control of the direction indicator lamps on the drawing tractor shall also operate the indicator lamps of the trailer.

c) In case of a failure - other than by short-circuit - of one of the direction indicator-lamp (turn-lamp), other such lamps must continue to flash, but the frequency in this condition may be different from 90±30 times/minute.

PRIOR ART

[010] US 4006453 A discloses a device for adapting combined brake and turn signal lights on a trailer to independent brake signal and turn signal lights on a towing vehicle has two circuits, one for each side, each circuit having a brake signal switch, such as a transistor, silicon-controlled rectifier or relay connected between the brake signal circuit of the vehicle and the filament of the combined brake and turn signal light on the corresponding side of the trailer. The brake signal switches are selectively actuated by impulses received from the corresponding turn signal flashers on the vehicle, to block the brake signal current to the corresponding signal light on the trailer. In one embodiment of the invention, voltage-sensitive switches (e.g., SCR) are connected to brake switch transistors, and the left-hand and right-hand turn signal circuits on the vehicle are connected through diodes to the corresponding signal lamps on the trailer, and also to their respective switches.

[011] When brakes are applied and turn signals simultaneously operated, the flashing turn signal triggers the voltage-sensitive switch on that side, causing the transistor to switch off, which prevents the brake circuit from lighting the combined lamp filament on that side while the filament is being flashed by the turn signal. The lamp on the other side remains lighted by the brake circuit. In another embodiment, relays or transistors are connected to the turn-signal circuits and brake signal circuits on each side of the towing vehicle in such a way that when one turn signal is operating, the brake signal for that side is blocked by the turn signal voltage, and is passed when the turn signal voltage is off. Thus, the trailer turn-signal lamp on the one side blinks at the same rate as the turn signal lamp on the vehicle, but 1800 out of phase with the latter.

DISADVANTAGES OF THE PRIOR ART

[012] In the existing tractor-trailer lighting systems, when operator switches on the turn signal while turning, all 3 turn indicators (Two on tractor and 1 on trailer) on the left-hand (LH) or right-hand (RH) side of the tractor are switched “ON” and special flasher is required whenever one of the bulbs is not working.

[013] However, tractor tail lamps or fender lamps are not visible due to trailer attached behind it and thus required to be switched off to save power. Also, when one of the turn indicator bulb fails, the flasher frequency needs to change, so that operator knows that one of the turn indicator in the tractor-trailer lighting system is not working.

OBJECTS OF THE INVENTION

[014] Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

[015] An object of the present invention is to provide a device for an improved tell-tale indication in towing vehicle and towed-vehicle combination, which can facilitate automatic switching of the turn indicator between the towing vehicle fender lamp and towed vehicle lamp.

[016] Another object of the present invention is to provide a device for an improved tell-tale indication in a tractor and trailer combination, which can facilitate automatic switching of the turn indicator between the tractor fender lamp and trailer lamps.

[017] Still another object of the present invention is to provide an improved device for switching the power supply between the towing vehicle fender lamp and towed vehicle lamps.

[018] Yet another object of the present invention is to provide an improved device for switching the power supply between the tractor fender lamp and trailer lamps.

[019] A further object of the present invention is to provide a device for an improved tell-tale indication in a tractor and trailer combination which substantially reduces the required system operating current.

[020] A further object of the present invention is to provide a device for an improved tell-tale indication in a tractor and trailer combination which uses optimized charging system.

[021] A still further object of the present invention is to provide a device for an improved tell-tale indication in a tractor and trailer combination which is easy for Tell-tale identification.
[022] A still further object of the present invention is to provide a low-cost device for tell-tale indication in a tractor and trailer combination.

[023] A still further object of the present invention is to provide a low-cost device for tell-tale indication in a tractor and trailer combination which offers an improved battery life.

[024] These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

[025] In accordance with the present invention, there is provided a device for automatic switching of turn indicators in tractors/towing vehicle towing a trailer/towed vehicle, the device comprises a multi-pole socket assembly fitted on tractor/towing vehicle and equipped with an integrated Single-Pole-Double-Throw (SPDT) switch for switching the power supply between the rear lamps of the tractor/towing vehicle and the trailer/towed vehicle lamps.

[0026] Typically, the device comprises:

• an ignition switch;

• a 12V battery;

• a flasher unit;

• a front (bumper) LH turn indicator;

• a front (bumper) RH turn indicator;

• a turn indicator switching unit;

• a multi-pole socket assembly integrated with a single-pole double throw (SPDT) switch;
• tractor/towing vehicle’s fender LH and RH turn indicators;

• trailer/towed vehicle’s LH and RH turn indicators;

wherein the SPDT switch is in Normally Closed (NC) position thereof until the trailer/towed vehicle connector is connected to the multi-pole socket assembly of the tractor/towing vehicle and the flasher unit changes the flashing frequency of the operational indicator lamps/bulbs of the tractor/towing vehicle and/or trailer/towed vehicle in case of one or more of the indicators/bulbs gets fused for warning the tractor/towing vehicle operator.

[0027] Typically, the Single-Pole-Double-Throw (SPDT) switch is automatically brought to Normally Open (NO) position thereof on connecting the trailer/towed vehicle connector to the multi-pole socket assembly of the tractor/towing vehicle.

[0028] Typically, the multi-pole socket assembly comprises:

• a top cover for pressing or releasing the SPDT switch for operation thereof;

• the cover having a hinged end for opening or closing the cover on the socket assembly; and

• a plurality of pins, preferably three pins on the bottom side of the socket assembly for attachment to the trailer/towed vehicle connector;

wherein the cover is normally closed for maintaining the Single-Pole-Double-Throw (SPDT) switch in a Normally Closed (NC) position thereof, and on connecting the pins of the socket assembly to the trailer/towed vehicle connector, the cover is automatically opened to release the Single-Pole-Double-Throw (SPDT) switch to be brought to a Normally Open (NO) position thereof.

[0029] Typically, the input terminals of the Single-Pole-Double-Throw (SPDT) switch are in contact with the flasher unit and the first output terminal thereof are connected to the tractor/towing vehicle’s fender LH and RH turn indicators.

[0030] Typically, the input terminals of the Single-Pole-Double-Throw (SPDT) switch are in contact with the flasher unit and the second output terminal thereof are connected to the trailer/towed vehicle’s LH and RH turn indicators.

[0031] Typically, the multi-pole socket assembly is configured to automatically open the Single-Pole-Double-Throw (SPDT) switch from the Normally Closed (NC) position to Normally Open (NO) position thereof, on connecting the socket assembly to the trailer/towed vehicle’s connector.

[0032] Typically, the Single-Pole-Double-Throw (SPDT) switch is configured to automatically return to the Normally Closed (NC) position thereof, on disconnecting the multi-pole socket assembly from the trailer/towed vehicle’s connector.

[0033] Typically, the multi-pole socket assembly is configured as a 7-pole socket assembly.

[0034] Typically, the device comprises a flasher unit configured to change the flashing frequency of the operational indicator lamps/bulbs thereof, in case of one or more of the indicators/bulbs gets fused.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[035] The present invention will be briefly described with reference to the accompanying drawings, wherein:

[036] Figure 1 shows a schematic circuit diagram for the device for automatic switching of turn indicators in a tractor configured in accordance with the present invention fitted on the tractor in a circuit position before attachment of the tractor or towing vehicle to a trailer or towed vehicle.

[037] Figures 2a to 2e show different views of a 7-pole socket assembly with an integrated Single-pole Double-throw (SPDT) switch in a closed position thereof as used in the device of Figure 1.

[038] Figure 3 shows a schematic circuit diagram for the device for automatic switching of turn indicators in a tractor configured in accordance with the present invention fitted on the tractor in a circuit position after attachment of the tractor or towing vehicle to a trailer or towed vehicle.

[039] Figure 4 shows a perspective view of a 7-pole socket assembly with an integrated Single-pole Double-throw (SPDT) switch in an open position thereof as used in the device of Figure 2.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[040] In the following, the device for automatic switching of turn indicators between the towing vehicle fender lamp and towed vehicle lamp configured in accordance with the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

[041] Figure 1 shows a schematic circuit diagram for the device 100 for automatic switching of turn indicators configured in accordance with the present invention fitted in a tractor or a towing vehicle to tow a trailer or a towed vehicle. In includes an ignition switch 10, a 12V battery 20, a flasher unit 30, a front (bumper) LH turn indicator 40, a front (bumper) RH turn indicator 45, a turn indicator switching unit 50, a single-pole double throw (SPDT) switch 60 for a 7-pole socket assembly 70 (see Fig. 2), a fender LH turn indicator 80, a fender RH turn indicator 85, a trailer LH turn indicator 90, and a trailer RH turn indicator 95. Here, the tractor/towing vehicle switch circuit is shown before attachment to the trailer/towed vehicle. Accordingly, the terminals of turn indicator switching unit 50 are connected to the terminals of fender LH turn indicator 80 and fender RH turn indicator 85.

[042] Figure 2a shows a perspective view of the 7-pole socket assembly 70 fitted with an integrated Single-pole Double-throw (SPDT) switch 60 (not visible) in a closed position thereof as used in the device 100 shown in Figure 1. Here the switch is shown in the closed position thereof, i.e. before attaching socket assembly 70 to the trailer/towed vehicle connector. This 7-pole socket assembly 70 includes a cover 72 for pressing or releasing said SPDT switch (60) for operation thereof. This cover 72 has a hinged end 74 for opening or closing thereof on socket assembly 70. Three pins 76 are also provided on the bottom side of socket assembly 70 for attachment to the trailer/towed vehicle connector. This cover 72 is normally closed for maintaining Single-Pole-Double-Throw (SPDT) switch 60 in a Normally Closed (NC) position thereof, and cover 72 is automatically opened to release Single-Pole-Double-Throw (SPDT) switch 60 to be brought to a Normally Open (NO) position thereof, on connecting pins 76 of socket assembly 70 to the trailer/towed vehicle connector.

[043] Figure 2b shows a top view of the 7-pole socket assembly 70 of Figure 2a and cover 72 hinged at one end 74 thereof is clearly visible here.

[044] Figure 2c shows a bottom view of the 7-pole socket assembly 70 of Figure 2a.

[045] Figure 2d shows a side view of the 7-pole socket assembly 70 of Figure 2a and hinged end 74 and three pins 76 to be connected to the connector of the trailer/towed vehicle socket are also visible here.

[046] Figure 2e shows another side view of the 7-pole socket assembly 70 of Fig. 2a and cover 72 and three pins 76 to be connected to the connector of the trailer/towed vehicle are also visible here.

[047] Figure 3 shows a schematic circuit diagram for the device 100 for automatic switching of turn indicators configured in accordance with the present invention fitted in a tractor or a towing vehicle to tow a trailer or a towed vehicle. The circuit includes an ignition switch 10, a 12V battery 20, a flasher unit 30, a front (bumper) LH turn indicator 40, a front (bumper) RH turn indicator 45, a turn indicator switching unit 50, a single-pole double throw (SPDT) switch 60 for a 7-pole socket assembly 70 (see Fig. 2), a fender LH turn indicator 80, a fender RH turn indicator 85, a trailer LH turn indicator 90, and a trailer RH turn indicator 95. Here, the tractor/towing vehicle switch circuit is shown after attachment of the tractor/towing vehicle to the trailer /towed vehicle. Accordingly, the terminals of turn indicator switching unit 50 are connected to the terminals of trailer LH turn indicator 90 and trailer RH turn indicator 95.

[048] Figure 4 shows a perspective view of a 7-pole socket assembly 70 fitted with an integrated Single-pole Double-throw (SPDT) switch 60 used in the device 100 shown in Figure 1. Here the switch 60 is shown in the open position thereof, i.e. after attaching socket assembly 70 to the trailer/towed vehicle. By opening of cover 72 on inserting the pins 76 in the connector of the trailer/towed vehicle, the SPDT switch 60 is released and activated to connect Normally Open (NO) contact to the respective turn indication system and automatically disconnects the rear fender LH and RH turn Indicator lamps.

WORKING OF THE INVENTION

[049] So, the idea underlying the present invention is to disconnect the tractor’s rear lighting system whenever the trailer connector is connected to tractor, because in any case, the tractor fender lights will be invisible from the rear after attaching trailer thereto. Thus, in this situation, only the tractor front lighting and trailer rear lighting system should work.

[050] With this new arrangement, no special flasher is required with this improvement, the existing flasher 50 itself can suitably meet the requirement when one of the turn indicators is not working.

[051] Accordingly, the automatic switching of the turn Indicator takes place between the fender and the trailer lamp, once the trailer/towed vehicle connector is connected to this 7-pole socket assembly 70 through pins 76 provided thereon. Here, this 7-pole socket assembly 70 is modified by adding a SPDT (Single-Pole, Double-Throw) switch 60 embedded therein (see Fig. 4) for switching the power supply between the fender and trailer lamps.

[052] Although, the present invention is described with reference to an agricultural vehicle drawing a trailer, the idea underlying the present invention can also be implemented on any combination of towing-towed vehicles. For example, a car towing a caravan, or a truck carrying a gun carriage.

[053] In the device for automatic switching of the turn indicator between the towing vehicle fender lamp and towed vehicle lamp which is configured in accordance with the present invention, facilitates in that in the event of no trailer connection, Normally Closed (NC) contact of the switch keeps the continuity of the respective turn indication system with the lamp.

[054] When the trailer connector is connected, the SPDT switch 60 gets activated, so Normally Open (NO) contact gets connected with the respective turn indication system. This automatically disconnects the rear fender LH and RH turn Indicator lamps.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

[055] The device for automatic switching of the turn indicator between the towing vehicle fender lamp and towed vehicle lamp has the following technical and economic advantages:

• Facilitates an automatic switching of turn Indicator between the fender and trailer lamp.
• Reduces the required system operating current.

• Uses an optimized charging system.

• Easy for Tell-tale identification.

• A low-cost solution.

• Improves Battery life.

[056] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.

[057] It is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

[058] Although, the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person in the art would readily recognize that these embodiments can be applied with modifications possible within the spirit and scope of the present invention as described in this specification by making innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies, in terms of their size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

[059] The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

[060] Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to imply including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

[061] The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

[062] The description of the exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top”, and “bottom” as well as derivatives thereof (e.g. “horizontally”, “downwardly”, “upwardly” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion.

[063] These relative terms are for convenience of description and do not require that the corresponding apparatus or device be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected”, refer to a relationship, wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. ,CLAIMS:We claim:

1. A device for automatic switching of turn indicators in tractors/towing vehicle towing a trailer/towed vehicle, said device comprises a multi-pole socket assembly fitted on tractor/towing vehicle and equipped with an integrated Single-Pole-Double-Throw (SPDT) switch for switching the power supply between the rear lamps of the tractor/towing vehicle and the trailer/towed vehicle lamps.

2. Device as claimed in claim 1, wherein said device comprises:

• an ignition switch (10);

• a 12V battery (20);

• a flasher unit (30);

• a front (bumper) LH turn indicator (40);

• a front (bumper) RH turn indicator (45);

• a turn indicator switching unit (50);

• a multi-pole socket assembly (70) integrated with a single-pole double throw (SPDT) switch (60);

• tractor/towing vehicle’s fender LH and RH turn indicators (80, 85);

• trailer/towed vehicle’s LH and RH turn indicators (90, 95);

wherein said SPDT switch (60) is in Normally Closed (NC) position thereof until the trailer/towed vehicle connector is connected to the multi-pole socket assembly (70) of the tractor/towing vehicle and said flasher unit (50) changes the flashing frequency of the operational indicator lamps/bulbs of the tractor/towing vehicle and/or trailer/towed vehicle in case of one or more of the indicators/bulbs gets fused for warning the tractor/towing vehicle operator.

3. Device as claimed in claim 1, wherein said Single-Pole-Double-Throw (SPDT) switch (60) is automatically brought to Normally Open (NO) position thereof on connecting the trailer/towed vehicle connector to the multi-pole socket assembly (70) of the tractor/towing vehicle.

4. Device as claimed in claim 1, wherein said multi-pole socket assembly (70) comprises:

• a top cover (72) for pressing or releasing said SPDT switch (60) for operation thereof;

• said cover (72) having a hinged end (74) for opening or closing said cover (72) on said socket assembly (70); and

• a plurality of pins (76), preferably three pins (76) on the bottom side of said socket assembly (70) for attachment to the trailer/towed vehicle connector;

wherein said cover (72) is normally closed for maintaining said Single-Pole-Double-Throw (SPDT) switch (60) in a Normally Closed (NC) position thereof, and on connecting the pins (76) of said socket assembly (70) to the trailer/towed vehicle connector, said cover (72) is automatically opened to release said Single-Pole-Double-Throw (SPDT) switch (60) to be brought to a Normally Open (NO) position thereof.

5. Device as claimed in claim 1, wherein the input terminals of said Single-Pole-Double-Throw (SPDT) switch (60) are in contact with said flasher unit (50) and the first output terminal thereof are connected to the tractor/towing vehicle’s fender LH and RH turn indicators (80, 85).

6. Device as claimed in claim 1, wherein the input terminals of said Single-Pole-Double-Throw (SPDT) switch (60) are in contact with said flasher unit (50) and the second output terminal thereof are connected to the trailer/towed vehicle’s LH and RH turn indicators (90, 95).

7. Device as claimed in claim 1, wherein said multi-pole socket assembly (70) is configured to automatically open said Single-Pole-Double-Throw (SPDT) switch (60) from the Normally Closed (NC) position to Normally Open (NO) position thereof, on connecting said socket assembly (70) to the trailer/towed vehicle’s connector.

8. Device as claimed in claim 1, wherein said Single-Pole-Double-Throw (SPDT) switch (60) is configured to automatically return to the Normally Closed (NC) position thereof, on disconnecting said multi-pole socket assembly (70) form the trailer/towed vehicle’s connector.

9. Device as claimed in claim 1, wherein said multi-pole socket assembly (70) is configured as a 7-pole socket assembly.

10. Device as claimed in claim 1, wherein said device comprises a flasher unit (50) configured to change the flashing frequency of the operational indicator lamps/bulbs thereof, in case of one or more of the indicators/bulbs gets fused.

Dated: this 31st day of May 2018. Digitally Signed.
(SANJAY KESHARWANI)
APPLICANT’S PATENT AGENT
REGN. No. IN/PA-2043.