FIELD OF THE INVENTION
The present invention relates to an apparatus for automatic cancellation of a
vehicle turn signal following completion of a turn. In a preferred aspect the present invention relates to automatic turn signal canceling system for vehicles which use handle bars as a steering means.
BACKGROUND OF THE INVENTION
A turn indicator system is an essential requirement in automotive vehicles. Such a system generally consists of two pairs of blinking lights (turn indicators), one pair comprising a left and a right indicator, mounted at the front of the vehicle, and another pair comprising a left and a right indicator mounted at the rear of the vehicle. A turn signal switch, which operates these lights, is located near the steering mechanism of the vehicle. Before taking a turn, the vehicle driver manually turns this switch ON. The indicators must then be turned OFF after the turn has been completed. In case of vehicles steered by a steering wheel, the indicators are generally automatically switched OFF after completion of the turn. However, in case of a vehicle with using handle bars as a steering means, such as a motorcycle, the mechanism used in steering wheel type systems is not appropriate and the turn signal switch has to be manually switched OFF after completion of turn.
The essential difference between a steering wheel type system and a handle bar type system is the degree of rotation that the steering wheel undergoes in relation to the turning of the vehicle - the steering wheel type system typically

undergoing more than one complete turn from lock to lock and the handle bar system being less than one complete turn from lock to lock. Although this specification will refer to handle bar steering systems, it is understood that the invention and the teachings herein have application to other steering systems which have this common characteristic with handle bar steering systems.
There are disadvantages in a manual switching OFF of turn signal indicators. Some times, the driver may forget to cancel the turn signal indicators after completing a turn. This is a safety issue owing to riders/drivers of trailing vehicles mistaking the turn signal. Also, there is a possible drain on the vehicle battery if the turn signal indicators remain in "ON" position for a long time.
To at least partially obviate problems mentioned above, the applicant has invented a system that automatically cancels the turn signal indicators of a handle bar steered vehicle after the vehicle completes a turn.
In the past, various attempts have been made to provide automatic cancellation turn signal system for motorcycles. However, their teachings are very different from the present invention, for an example:
US 4792785 and JP58047639: Illustrate a turn signal canceling device comprising a turning angle detecting arrangement, a distance measuring arrangement and an elapsed time measuring means.

us 5260685: Illustrates a time delayed self canceling turn signal.
US 3555507: Illustrates turn signal canceling by a pulse counting technique.
US 4658236: Illustrates an automatic signal canceller v\/hich operates by
detecting the angle of turning movement by changing values of a variable
resistor.
US 4398175: Illustrates a device for automatically canceling a turn signal in
response to a shift in the center of gravity of a vehicle.
US 4403211: Illustrates an automatic turn signal canceling device for
motorcycles that compares a steering angle signal and a peak signal value in
order to generate a turn signal canceling signal and activate a solenoid switch.
US 4030066: Illustrates a system for canceling a turn signal with the use of a
spring returned gyroscope.
JP 2003252112: Illustrates a turn signal control device comprising a turning
angle detecting arrangement and a travel distance detecting means.
JP 2002019520: Illustrates a turn signal automatic cancellation device
comprising a turning angle detector, a vehicle speed detector and a vehicle
angular speed detector.
US 4125827: Illustrates an automatic cancellation of a turn signal when vehicle
transmission is shifted from low gear to high gear.
US 4333071: Illustrates a self canceling device for a vehicle turn indicator, using
relative steering angle, distance and velocity of the vehicle.
US 4358751: Illustrates an automatically canceling turn signal device responsive
to predetermined increase in vehicle velocity.

us 6414593: Illustrates a turn signal canceling mechanism responsive to the tilt
of a vehicle during turning.
US 5790017: Illustrates a vehicle turn signal control system and method that
includes a turn signal lever, a dipswitch with an at least dual position toggle
switch and control circuitry.
US 6020813: Illustrates a self cancellation vehicle turn signal with safety
reactivation, using a timing circuit to electrically activate and deactivate the
flashing turn signal.
WO 2005/009822A2 discloses a system of turn signal canceling that
predominantly uses timer logic.
With increased and faster traffic it has become more essential to upgrade the turn indicator control mechanism in a handlebar steered vehicle such as a motorcycle. Many of the above attempts are based on the time of travel and distance of travel during vehicle turning to reset such indicators automatically. In almost all of these attempts the physical dynamics of the vehicle have been ignored. The prior art generally requires complicating processing in detection apparatus, devices and steps involved followed. The prior art also has generally evidenced a high occurrence of operational error in the cancellation step.
The present invention attempts to overcome, at least in part, many of these problems.

OBJECTS OF INVENTION:
An object of the invention is to provide an improved automatic canceling means for a turn indicator system in a handle bar steered vehicle.
Another object of the invention is to provide an improved automatic canceling means for a turn indicator system in a handle bar steered vehicle which is responsive to the extent of turning of the handle bar with respect to the vehicle frame.
Another object of the invention is to provide an improved automatic canceling means for turn indicator system in a handle bar steered vehicle which senses the direction of turning of the vehicle.
Another object of the invention is to provide an improved automatic canceling means for a turn indicator system in a handle bar steered vehicle which is simple in construction.
Another object of the invention is to provide an improved automatic canceling means for a turn indicator system in a handle bar steered vehicle which is cost effective.

Another object of the invention is to provide an improved automatic canceling means for a turn indicator system in a handle bar steered vehicle, with with the canceling means having no moving parts.
Another object of the invention is to provide an improved automatic canceling means for a turn indicator system in a handle bar steered vehicle which enhances safety.
Another object of the invention is to provide an improved automatic canceling means for a turn indicator system in a handle bar steered vehicle which avoids excessive drain of the battery.
In order to satisfy the objectives mentioned above, the applicants have invented a system which automatically cancels the turn signal of a handle bar steered vehicle after completing a turn.
STATEMENT OF INVENTION :
According to one aspect of the present invention there is provided a system, which automatically cancels the turn signal of a handle bar steered vehicle after the vehicle has completed a turn.
The system comprises a manually activated turn signal switch, a reference means, a sensing means, and a processing means, one of the reference and

sensing means being mounted on a element constrained to move with the vehicle handle bars, such as a steering column or fork assembly, the other of the reference and sensing means being mounted on a vehicle frame, and the processing means being arranged for processing signals from the sensing means and canceling the turn signal.
Preferably the reference means is constrained to move with the handle bars and the sensing means is located on the vehicle frame.
Preferably the reference means comprises magnets;
Preferably the sensing means comprises sensors in the form of non contact switches, such as reed switches or Hall Effect sensors, which react to the presence of magnetic flux of the magnets;
Preferably, a "STRAIGHT AHEAD" position is determined when two Hall Effect sensors, being a left Hall Effect sensor and a right Hall Effect sensor, are both sensing proximity to a common fixed magnet;
Preferably, a "LEFT TURN" signal is determined when the left hall effect sensor is not sensing the fixed magnet and vice versa in the case of a right turn signal;
Preferably, the system includes a manual over-ride.

Preferably, the processing means comprises a turn signal logic controller for a handle bar steered vehicle, wherein whilst the turn signal is activated a timer means computes a turning-time, being the time that the steering system is in a turning mode in the direction of the turning signal, and a straight-ahead time, being the time that the steering system is not in a turning mode, and the processing means turns off the turning signals if the turning-time exceeds a first preset time, the straight-ahead time signal exceeds a second preset time, and the steering system is not in a turning mode.
Preferably, the turning-time is computed as a result of a sensor sensing a reference mark when the vehicle is in the turning mode, and the straight-ahead time is computed as a result of a sensor not sensing a reference mark when the vehicle is not in the turning mode.
In this way the dynamics of a handle bar steered vehicle is utilized and exploited for the control. The present invention detects and tracks the direction and change in the handle bar angle as well as monitors the duration of the changing period. As a result, a driver can make sharp lane changes, accelerate, decelerate, make mid corner adjustments or stop at a traffic signal after the turn signal indicator has been manually switched ON by the driver without activating the turn signal canceling system.

Preferably, the invention comprises an arrangement to avoid inadvertent and erroneous signal getting generated by the sensing means due to misalignment of the mounts for the said reference means and the sensing means, for instance during assembly.
In accordance with a second aspect of the present invention there is provided a system for canceling a turn signal of a handle bar steered vehicle, the system comprising:
a magnet and two sensing means mounted on the handle bar and the vehicle frame respectively or vice versa enabling detection of handle bar angle with respect to the frame of the vehicle;
a turn signal generating means for generating one of a "LEFT TURNING" signal, a "RIGHT TURNING" signal or a "STRAIGHT-AHEAD" signal in response to the sensing means sensing whether or not the handle bar has moved angularly with respect to the vehicle frame; and
a logic controller means having a first timer means, a second timer means, a memory and a processor;
the first timer means arranged to compute a first timer output signal in response to duration of the turn signal generating means in a "LEFT TURNING" or a "RIGHT TURNING" position corresponding to the vehicle turning duration;
the second timer means arranged to compute a second timer output signal in response to duration of the turn signal generating means in the

"STRAIGHT-AHEAD" position corresponding to the vehicle straightening
duration;
the memory arranged to store information which includes a first
predetermined turn time and second predetermined restore time;
the logic controller means being connected to the left turn signal switch
and including switching means for transmitting said signal from switching
means to open (or switch off) the left turn signal switch when the left turn
signal switch is closed (or switched on) due to manual activation, when:
- the first timer output signal corresponds to a duration of the turn signal generating means in "LEFT TURNING" position beyond the first predetermined turn time, and
- the second timer output signal corresponds to duration of switching means In "STRAIGHT-AHEAD" position beyond the second predetermined restored time, and the switching means is generating said "STRAIGHT-AHEAD" signal.
Preferably a corresponding arrangement is used in the case that the right turn signal switch is activated.
During the movement of the handle bar, the sensing means moves in or out of the magnetic field of the magnet. The signal generating means and a logic controller capture these movements (including, importantly, the direction of these movements), compute the duration of such movements and thereby ensure

sufficient time interval is given and available for the intended turn by the vehicle rider. The system ensures that the vehicle has actually completed taking the intended turn and is moving in a relatively straight drive before signal cancellation is effected. The inadvertent cancellation of turn signal during the interim period of executing a turn is prevented substantially by the system of the invention. Hence, the present invention provides a reliable turn signal cancellation device that ensures switching OFF of turn indicators at appropriate time without undue advance or undue delay in the process. The invention, though defined and described as applicable to a two-wheeler having a handle bar, can be extended to any motorized vehicle having a handle bar or a handle bar like steering means.
BRIEF DESCRIPTION OF THE DRAWINGS :
It will be convenient to further describe the invention with reference to the accompanying drawings which illustrate preferred embodiments of the automatic turning signal canceling system of the present invention. Other embodiments are possible, and consequently, the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention. In the drawings:
Figure 1 illustrates the location of system parts with the help of right hand side view and top view and enlarged views of a motorcycle having a turn signal canceling system in accordance with the present invention.

Figure 2 Illustrates the location of various parts of the system on a motorcycle frame.
Figure 3 illustrates details of the mounting brackets for sensing means and reference means used in accordance with the present Invention.
Figure 3a illustrates an Isometric view of the arrangement of Figure 3.
Figure 4 illustrates the top view and enlarged view of a motorcycle having the system of Figure 1 when the handle bar is in straight condition, that Is when the vehicle moving in straight direction.
Figure 5 illustrates the top view and enlarged view of the motorcycle of Figure 4 when the handle bar Is in turned condition when the vehicle is turning left.
Figure 6 Illustrates the flow chart of logic of the system in accordance with the present invention when the vehicle is turning left. A similar logic applies when the vehicle is turning right.
DESCRIPTION OF PREFERRED EMBODIMENT(S) :
According to a preferred embodiment of the present Invention, as depicted in Figures 1, 2, 3 and 3a, an automatic turn signal canceling system for a motorcycle consists of a turn signal switch (1), a logic controller (2), a fork

assembly (3), a frame (4), a magnet (5) (shown in Figure 3), a magnet mounting bracket (6) (in Figure 3 and 3a), a sensing means LH (7), a sensing means RH (8) mounted on a bracket (9) (Figure 3a), a handle bar (10), a front LH turn signal indicator lamps (11), a front RH turn signal indicator lamps (12), a rear LH turn signal indicator lamps (13) and a rear RH turn signal indicator lamps (14). The sensing means LH (7) and sensing means RH (8) are mounted on frame (4) of the vehicle through sensor mounting bracket (9) (as shown in Figure 3). The magnet (5) is mounted on a fork assembly (3) of vehicle through a magnet mounting bracket (6) as shown in Figure 3. The handle bar (10) is also mounted on the fork assembly (3). The mounting brackets 6 and 9 are provided with U shaped slots 16 and 17 respectively as shown in Figures 3 and 3a.
The method of working of the automatic turn signal cancellation system as per the present invention is explained below when the vehicle is taking a left turn. A similar description is applicable for a right side turn.
When the vehicle is moving in a straight direction (figure 4), the sensor LH (7) and sensor RH (8) are in the magnetic field of magnet (5). Therefore the signal generating means, for example Hall sensors in this case (not shown) in both sensors indicates "STRAIGHT-AHEAD" position.
When the rider intends to take a left turn, he has to operate manually operate the turn signal switch to "LEFT" position. The logic controller is activated as soon as

the turn signal switch is operated. The flow chart (figure 6) depicts the logic, when the vehicle is taking a left turn, which is explained below (A similar logic holds good when the vehicle is taking a right turn).
When the handle bar is turned by a predetermined angle to left side, the sensor LH (7) comes out of the magnetic field of magnet (5) and the signal generating means, the Hall sensor (not shown) in the sensor LH (7) generates a signal indicating "LEFT TURNING" position. The logic controller unit checks whether the Hall sensor has remained in "LEFT TURNING" position for a predetermined time. After the vehicle has completed the turn, the handle bar returns to the straight position and the Hall sensors LH (7) and RH (8) generate a "STRAIGHT-AHEAD" signal as the sensor (7) is now within the magnetic field of the magnet (5). The logic controller unit checks whether the LH and RH Hall sensors have remained in "STRAIGHT-AHEAD" position for a predetermined time. After a predetermined time has elapsed, the logic controller unit generates a signal to cancel the turn indicators.
If the turn signal switch has been manually turned on and the handle bar continues to be in "STRAIGHT-AHEAD" position, the logic controller checks whether either sensing means has encountered a "TURNING SIGNAL" within a predetermined time after the turn signal indicator has been switched on. If the predetermined time elapses with the handle bar in "STRAIGHT-AHEAD" position.

the logic controller generates a signal to automatically switch off the turn signal indicators.
This embodiment of the invention conveniently provides a built in logic control to prevent automatic cancellation of the turn signal indicators, manually switched to point to the other direction; that is, if the rider intends to take a left turn (as in the above example); has manually switched on the turn signal indicators to left position and begins to execute a right turn, the logic controller senses the position of the handle bar owing to signal generated by the sensing means and prevents cancellation of the turn signal indicator.
Conveniently, a pair of U shaped slots 16 and 17 (Figures 3 and 3a) is provided on the mounting brackets 6 and 9 respectively to facilitate alignment of the two mounting brackets. During assembly operation, a suitable calibration means such as a straight metal rod is inserted through the slots to ensure alignment of the brackets before further assembly operation. This would ensure that assembly related misalignment of the two brackets does not cause inadvertent signal generation owing to proximity of either of sensing means to the reference means.
In a preferred embodiment of the invention, the said logic controller is a part of the electronic control system of the vehicle. Therefore, this embodiment does not require a separate electronic circuitry and associated parts making the arrangement simple and cost effective.

In various embodiments this system can be used for any vehicle, which has a handle bar as a steering means such as a motorcycle, a three wheeled vehicle etc.
In an alternative embodiment of the Invention, optical and laser switches can be used in place of Hall sensors to sense the turning angle of the handle bar.
In another embodiment of the invention, the mounting positions of sensors and the magnet can be interchanged, that is the sensors may be mounted on the fork and the magnet may be mounted on the frame of the vehicle.
The present invention allows the use a simple detection and signaling mechanism, which can be altered and fitted according to the needs, space available, and assembly demand, making the invention very useful and highly effective. The basic principle of the system lies in tracking the movement of the handle bar precisely with respect to the vehicle frame over a preset period of time after the turn signal is actuated, and matching the to and fro movement of the handle bar with respect to the vehicle frame with prescribed conditions for deciding the cancellation of the turn signal. Usefully, no major modifications are required in a conventional vehicle in order to incorporate the system. No structural alterations are required for incorporating the system in a conventional vehicle. The method of operation and device included do not have moving parts, hence the system is simple in construction. The method and device do not affect

the performance of the vehicle. The method and device are self sufficient and work independently without interfering with the normal operation of the vehicle, and make no extra demand on the rider.
It is to be expressly understood that though the descriptions of the preferred embodiments and the annexed drawings refer to sensors being within the magnetic field when the handle bars are in their normal position, the same principle can be extended to sensors positioned beyond the magnetic field when the handle bars are in their normal position. Furthermore, the location of the magnet and the sensor can be interchanged mutually between the fork and the frame of the vehicle. It is only the relative movement of the sensors and the magnet which enable the detection of movement of the handle bar by sensing the presence and absence of the magnetic field in the sensors. The interchangeability of the physical relationship of the magnet and the sensor and the magnetic relationship of the magnet and the sensor will be well understood and appreciated by persons skilled in the relevant art.
An alternative embodiment includes two magnets and one sensor, the magnets or the sensor being mounted rigidly on the fork and the other mounted rigidly on the frame, such that such that the sensor is capable of moving into and out of the magnetic field due to the movement of the handle bar, which duration is computed for controlling and signaling the cancellation of turn in signal indicator.

It is evident that the placement of the magnet(s) and the sensor Is irrelevant as long as one of the two is placed in a fixed position on the rigid part of the vehicle i.e. the frame and the other one is placed in a fixed position in the moving part of the vehicle i.e. the handle bar. Also the positioning of the base position between the magnet and the sensor is irrelevant as they can be placed in normal position such that the sensor is within the magnetic field in normal position and moves out during the turn or vice-versa. The broad principle used in the invention is the use of the sensor moving in and out of a magnetic field corresponding to the movement caused in the handle bar by the driver, which corresponds to the turning of the vehicle. Conversely, the handle bar movement is detected by the said sensors and captured by the logic circuit for signaling the control circuit controlling the cancellation of the turn signal indicator.
Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. For instance, the mounting positions of the sensing means and the reference means may be altered without disturbing the basic principle of working. The design of the mounting means may be different. The sensing means may be a contact type or any one of various other non contact types. Other possible variations and modifications will be apparent.

WE CLAIM:
1. A system for canceling a turn indicator signal on a vehicle, the system comprising a manually activated turn signal switch, a reference means, a sensing means, a timer means, and a processing means; wherein the relative positions of the sensing means and the reference means change during turning of the vehicle and the sensing means provides a signal indicate of the relative positions, the processing means processes the signal output from the sensing means and the timer means to provide an output signal canceling the turn signal switch in response to predetermined conditions.
2. A system for canceling a turn indicator as claimed in claim 1 when the vehicle is steered by handle bars.
3. The system as claimed in Claim 1 or 2 where one of the reference means or the sensing means is mounted on a steering column and the other on a vehicle frame.
4. The system as claimed in any preceding claim, where a "LEFT TURN" signal is generated by the sensing means when a left mounted sensing means is not sensing the reference means.
5. The system as claimed in Claim 4 where a "STRAIGHT AHEAD" signal is generated by the sensing means when the left mounted sensing means returns to proximity with the reference means and cancels the "LEFT TURN" signal.

6. The system as claimed in Claim 5, where the said cancellation of the "LEFT TURN" signal causes the processing means to switch off the manually activated turn signal switch.
7. The system as claimed in any preceding claim, where a "RIGHT TURN" signal is generated by the sensing means when a right mounted sensing means is not sensing the reference means.
8. The system as claimed in Claim 7 where a "STRAIGHT AHEAD" signal is generated by the sensing means when the right mounted sensing means returns to proximity with the reference means and cancels the "RIGHT TURN" signal output of the logic unit.
9. The system as claimed in Claim 8, where the said cancellation of the "RIGHT TURN" signal causes the processing means to switch off the manually activated turn signal switch.
10. The system as claimed in any preceding claim where the reference means is a magnet.
11. The system as claimed in any preceding claim where the sensing means comprises non-contact type switch such as the reed switch or the Hall Effect switch, which respond to the changing magnetic flux.
12. The system as claimed in any of the preceding Claims wherein whilst the turn signal indicators are manually activated, the timer means computes a turning-time being the time that the vehicle is in a turning mode in the direction of the turning signal, and a straight-ahead time being the time that the vehicle is not in a turning mode, and processing means turns off

the turning signals if the turning-time exceeds a first preset time, the straight-ahead time signal exceeds a second preset time, and the steering system is not in the turning mode.
13. The system as claimed in claim 12 where the turning-time is computed as
a result of a sensing means sensing a reference mark when the vehicle is
in the turning mode, and the straight-ahead time is computed as a result of
a sensing means not sensing a reference mark when the vehicle is not in
a turning mode.
14. The system as claimed in any of the preceding Claims, comprising a pair
of slots, the first slot on the vehicle frame and the second on the steering
assembly, whereby a calibrating process in vehicle assembly aligns the
position of the said two slots.
15. A turn indicator system as substantially claimed in Claims 1 to 14 and as
applied to a two wheel vehicle with a handlebar.
16. A turn indicator system as substantially claimed in Claims 1 to 14 and as
applied to a three wheel vehicle with a handlebar.
Dated this the 18*'' day of July, 2007.