GB2351192A

GB2351192A - Turn direction indicator for vehicle

Info

Publication number: GB2351192A
Application number: GB0011342A
Authority: GB
Inventors: Shinichi Sugawara
Original assignee: Nippon Yusoki Co Ltd
Current assignee: Nippon Yusoki Co Ltd
Priority date: 1999-06-15
Filing date: 2000-05-12
Publication date: 2000-12-20
Anticipated expiration: 2020-05-12
Also published as: JP2000355246A; GB2351192B; GB0011342D0; DE10028601A1; FR2795030A1; FR2795030B1

Abstract

A vehicle direction indicating system where the indicators are cancelled either by a first extinguishing means where the steering direction of the vehicle is opposite to that being indicated, or a second extinguishing means where a shut-off signal is generated following a predetermined period of time. The indicators may also be manually cancelled. The first extinguishing means may be carried out by detecting steering torque. The two means may also be combined where the time period of the second means starts upon receipt of a steering direction signal of the first means. The system is particularly suitable for use in a fork-lift truck.

Description

2351192 TURN DIRECTION INDICATOR FOR VEHICLE

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a turn direction indicator for a vehicle, and specifically relates to a turn direction indicator that is preferably used for industrial vehicles, such as forklift trucks.

2. Description of the Related Art

It is usual in a turn direction indicator that an operator operates a turn signal switch to illuminate either a right or left turn signal lamp. The turn signal switch is locked in a state of tilting to a right or left by a manual operation and the turn signal lamp for direction of the tilt remains in the light-on state while in the lock state. In order to extinguish the illuminating turn signal lamp, the turn signal switch that has been locked in the state a tilt to the right or the left is returned to the neutral state by a manual input operation. That is, the operator manually operates the turn signal switch both to illuminate the turn signal lamp and to extinguish the illuminating turn signal lamp.

With the above-described conventional art, the turn signal switch requires manual input operations by the operator at both illuminating and extinguishing the turn signal lamp. Forklift trucks or similar industrial vehicles require the operators not only to carry out both vehicle driving operations and fork operations simultaneously but also frequent moving direction changes of the vehicle. Under this circumstance, however, it is extremely troublesome for the operator to directly operate the turn signal switch each time of both illuminating and extinguishing the turn signal lamp so as having done conventionally, and this has been liable to result with occurrence of accidents due to abstraction of attention by operations of illuminating and extinguishing the turn signal lamps and with failure in illuminating or extinguishing the turn signal lamp.

SUMMARY OF THE TNVENTTON

An object of the present invention is to provide a turn direction indicator for a vehicle that ensure safe driving operation of vehicles for operators who will not be abstracted by turn signal operations.

For achievement of the above-described objects, the invention includes the following technical means. These are now described with use of symbols appropriated for the embodiments in attached drawings; wherein the invention provides a turn direction indicator that comprises a turn signal lamp that is caused to be illuminating or extinguished in accordance with a direction of right-handed or left-handed turn of a vehicle, direction indicating means for illuminating an appropriate turn signal lamp and extinguishing means for extinguishing an illuminating turn signal lamp; which is characterized by that the extinguishing means comprises first extinguishing means for detecting the steering direction of the vehicle and extinguishing a right or left turn signal lamp by outputting a light-off signal when a concerned steering direction becomes opposite to the direction that has been input by the direction, indicating means and second extinguishing means for extinguishing the right or left turn signal lamp by outputting a light-off signal after expiration of a predetermined duration of time from input by the direction indicating means.

This is also characterized by that the aforenamed extinguishing means comprises third extinguishing means for extinguishing the turn signal lamp forcibly through input operation by the operator.

It is further characterized by that the aforenamed direction indicating means has a structure of automatic reset to a neutral state after being tilted to the right or the left by the operator.

BRIEF DESCRIPTION QF DRAWINGS

Fig. 1 is an electric circuit diagram for the turn signal related to the first embodiment of the invention.

Fig. 2 shows a left side view of the turn signal as the first embodiment of the invention, in a state of attachment to 3 the vehicle.

Fig- 3 is a front view of the turn signal as the first embodiment of the invention, in a state of attachment to the vehicle.

Fig. 4 is an electric circuit diagram for the turn signal related to the second embodiment of the invention.

DETAILED DESCRIETTON OF THE PRESENT INVENTION With references to corresponding attached drawings, modes of embodiment of the invention are now described in detail- A first embodiment of the invention is described with references to Figs 1-3- A four-wheeled, counter-balance-type forklift truck 1 is provided with a pair of right and left masts 3 that stand at front parts of moving direction of a vehicle body 2 and a pair of forks 4 are so provided as to be allowed to ascend and descend along the masts 3. The vehicle body 2 is provided with a seat 5 for an operator to sit on for driving operation at a center thereof and with an operating apparatus 6 for driving operations of the forklift truck by the operator. A head guard 7 for protecting the operator from a falling object is provided at a position above the seat 5, and a pair of head lamps 8a and 8b are secured at upper parts of front pillars of the head guard 7. A left turn signal lamp 9a and a right turn signal lamp 9b are secured respectively at positions under the headlamps 8a and 8b.

Fig. 1 shows an electric circuit diagram for illuminating the right and left turn signal lamps 9a and 9b. Direction indicating means that is operated by the operator is provided in the vicinity of a steering wheel 11 in the operating apparatus 6. The direction indicating means is an automatic-reset-type turn signal switch 10 that has a structure wherein automatic resets are carried out on input of the right and left turns by the operator. To describe concretely, it is a momentary toggle switch that is so provided as to tilt freely with an axis 12 as the center in such manner as arrows indicate, and each of springs 13 apply force for the automatic reset to the neutral position. The turn signal switch 10 has a structure wherein, when the turn signal switch is tilted to the left, a sectorial plate 14 that is fastened to the bottom end operates to turn on a leftturn-signal limit switch 15a and, when tilted to the right, a right-turn-signal limit switch 15b is turned on.

The electric circuit further comprises first extinguishing means, and the first extinguishing means has a torque sensor 19 for detecting a steering direction of the steering wheel 11, a discriminator 20 for receiving signals from the torque sensor 11 and discriminating the steering direction of the steering wheel 11, and a timer 21 that starts time measurement on reception of signals from the discriminator 20 and that outputs a one-shot signal after expiration of a predetermined duration of time. It also comprises a total timer 17, a left-turn-signal RS flip-flop 16a (hereinafter referred to as left- turn-signal FF 16a) and a right -turn-signal RS f'Lip-flop l6b (hereinafter referred to as right -turn-s ignal FF l6b), and a left-turn- signal OR circuit l8a and a rightturn-signal OR circuit 18b.

A set input pin S on the left-turn-signal FF 16a receives either an ON or OFF signal from the lef t-turn-signal limit switch 15a and a reset input pin R receives either an ON or OFF signal from the left-turn-signal OR circuit 18a. In the same way, a set input pin S on the right -turn-signal FF 16b receives either an ON or OFF signal from the right -turn-signa 1 limit switch 15b and a reset input pin R receives either an ON or OFF signal from the right-turn-signal OR circuit 18b.

The total timer 17 is a timer that starts time measurement on reception of the ON signal from either the left-turn-signal limit switch 15a or the right-turn-signal limit switch 15b and that outputs a one-shot signal after expiration of a predetermined duration of time. The left-turnsignal OR circuit 18a is a logical circuit that receives Output signals from the right-turn-signal limit switch 15b, one-shot output signals from the timer 21, one-shot output signals from the total timer 17 and output signals from a cancellation switch 22. In the same manner, the right-turnsignal OR circuit 18b is a logical circuit that receives output signals from the leftturn-signal limit switch 15b, one-shot output signals from the timer 21, one-shot output signals from the total timer 17 and output signals from a cancellation switch 22.

The cancellation switch 22 is a push-button-type switch that is disposed in the vicinity of the turn signal switch 10 and that forcibly extinguishes illuminating left or right turn signal lamp 9a or 9b. An input operation by the operator causes the cancellation switch 22 to output ON signals to the left-, turn-signal OR circuit 18a and the rightturn-signal OR circuit 18b.

In accordance with the structure described above, operations of the electric circuitry are now described. A first case wherein a turn signal is input while a vehicle 1 is -stopped or traveling straight forward and a second case wherein the turn signal is input while the vehicle I is turning to the right or to the left are described hereafter.

Firstly described is the first case wherein a left turn signal is input while a vehicle 1 is stopped or moving straightforward. The turn signal switch 10 is tilted to the left to illuminate the left turn signal lamp 9a. This causes the left-turn-signal limit switch 15a to be turned on temporarily and an ON signal to be output. The ON signal is output to the left-turn-signal FF 16a, the total timer 17 and the rightturn-signal OR circuit 18b. So long as the left-turn-signal OR circuit 18a does not receive any one of the ON signal from the right-turn-signal limit switch 15b, the ON signal from the total timer 17, the ON signal from the timer 21 and the ON signal from the cancellation switch 22, the OFF signals remains to be output to the left- turn-signal FF 16a.

That is, reception of the ON signals as the set input and the OFF signals as the reset input to the left-turn-signal FF 16a results with output of an ON signal from a first output pin Q1 of the lef t-turnsignal FF 16a and an OFF signal from a second, output pin Q2 to illuminate the left turn signal lamp 9a.

To focus on the right -turn-s ignal FF 16b, the input of the OFF signal from the right-turn-signal limit switch 15b to the set input pin S is accompanied by the input of the ON signal from the right-turn-signal OR circuit 18b. The right-turn-signal OR circuit 18b is so designed as to output ON signals on input of the ON signals from the left-turn-signal limit switch 15a, the OFF signal from the total timer 17 and the OFF signal from the timer 21. Thus, with the input thereof, the right-turnsignal FF 16b so outputs an OFF signal from a first output pin Q1 and an ON signal from a second output pin Q2 as to maintain the right turn signal lamp 9b in the extinguished state.

Next, with the input of the turning direction, the steering wheel 11 is operated to rotate in the left-hand direction in the state wherein the left turn signal lamp 9a is illuminated. The illumination is maintained because the left-turn-signal FF 16a receives the OFF signal at the set input pin S and also the OFF signal at the reset input pin R.

Now described is the case wherein the illuminating left-turn-signal lamp 9a is distinguished. There are two cases for extinguishment of the left-turn-signal lamp 9a. Afirst case is extinguishment caused by the operation of the steering wheel 11 to the right-hand direction and a second case is extinguishment effected by the total timer 17.

Firstly described is the extinguishment caused by the turning operation of the steering wheel 11. When the steering wheel 11 that has been operated to turn to the left is turned to the opposite direction, that is, to the right, the torque sensor 19 detects the steering torque, and a signal is output to the discriminator 20. The discriminator 20 discriminates the turning direction of the steering wheel 11 and, in case a detected value of the torque is the predetermined value or larger, outputs a right-hand-turn detecting signal is output to the timer 21. On reception of the signal from the discriminator 20, the timer 21 starts time measurement at the same time as the input and, after expiration of the predetermined duration of time, a one-shot ON signal is output- The one-shot ON signal that has been output from the timer 21 is input to the left-turn-signal OR circuit 18a.

This causes output of the ON signal from the leftturn-sigpaj OR circuit 18a and output of the OFF signal from the lef t-turn-signal limit switch 15a, and thus the lef t-turn-signal FF 16a receives the OFF signal as the set input and the ON signal as the reset input. The first output pin Ql of the leftturn-signal FF 16a outputs the OFF signal and the second output pin Q2 outputs the ON signal while the lef t-turn- signal lamp 9a is extinguished. In case the output timing of the one-shot ON signal from the timer 21 is so conditioned as to be effective only with the predetermined or larger torque value and after expiration of the predetermined duration of time, the illuminating turn signal lamp, either the left-turn-signal lamp 9a or the right turn signal lamp 9b, can be prevented from being extinguished at a temporary or momentary turn of the steering in the opposite direction during turning operation of the steering wheel 11. This may be conditioned in other ways or unconditioned.

As described above, the turning operation of the steering wheel 11 for the right turn, which is detected by the torque sensor 19, causes extinguishment of the left-turn-signal lamp 9a. Although the torque sensor 19 is capable of torque detection during the turning operation of the steering wheel 11, the torque cannot be detected without the turning operation of the steering wheel 11, and thus, as a compensation thereof, the total timer 17 is provided; the total timer 17 operates as described below.

When the left-turn-signal limit switch 15a is turned on, an ON signal is input to the total timer 17 and the total timer 17 starts time measurement. After expiration of a predetermined duration of time for the measurement, the total timer 17 outputs a one-shot ON signal. The oneshot ON signal that is output from the total timer 17 is input to the left-turn-signal OR circuit 18a. This causes output of the ON signal from the left- turn-signal OR circuit 18a and output of the OFF signal from the left- turn-signal limit switch 15a, and the left-turn-signal FF 16a receives the OFF signal as set input and the ON signal as reset input.

Consequently, the first output pin Q1 of the leftturn-signal FF 16a outputs the OFF signal while the second output pin Q2 outputs the ON signal, which causes extinguishment of the left-turn-signal lamp 9a. That is, the total timer 17 always starts time measurement on input of the ON signal from either the left-turn-signal limit switch 15a or the right turn-s igna 1 limit switch 15b, irrelevant to the direction of turning operation of the steering wheel 11, and extinguishes either the left-turnsignal lamp 9a or the right turn signal lamp 9b after expiration of the predetermined duration of time, also extinguishing either the left-turnsignal lamp 9a or the right turn signal lamp 9b in the neutral state of no turning operations at the steering wheel 11, or in the case of no torque detection.

In case where the steering wheel 11 is turned in the direction opposite to the entered turning direction, the illuminating left-turn-signal lamp 9a or the right turn signal lamp 9b are extinguished by the torque sensor 19 that is the first extinguishing means, and, even in a case where the torque detection is disabled because of a failure in the first extinguishing means, the total timer 17 ensures extinguishment of the left-turnsignal lamp 9a or the right turn signal lamp 9b.

Although the left-turn indication is input as an initial input while the vehicle 1 is stopped or moving straight forward, in a case where the right-turn indication is input as the initial input, the right turn signal lamp 9b is illuminated and extinguished in the same way as the above-described illuminating and extinguishing operation of the left-turnsignal lamp 9a.

Now described is the second case wherein direction of a left or right turn is input while the vehicle 1 is in the course of a left turn. In a case where a left turn direction is input in the course of left turn, the left-turn-signal lamp 9a is illuminated in the same way as described for the case of the stopped vehicle or moving straight forward. In case the steering wheel 11 is turned to the right in this state, detection by the torque sensor 19 causes the left-turn-signal lamp to be extinguished. In a case where a right turn direction is input in the course of left turn, the right turn signal lamp 9b is illuminated but extinguished instantly since the torque sensor 19 detects a left-turn torque. The illumination and extinguishment of the right turn signal lamp 9b in a case of a right or left turn direction in the course of the right turn are approximately the same as the illumination and extinguishment of the lef-t-turn-signal lamp 9a.

Now described are the operations of the cancellation switch 22. In case an operator desires to extinguish the left-turnsignal lamp 9a or the right turn signal lamp 9b for such a reason as a mistake after the leftturn-signal lamp 9a or the right turn signal lamp 9b is illuminated, the cancellation switch 22 is operated to output the ON signal to the leftturn-signal OR circuit 18a or the right-turn-signal OR circuit 18b. The ON signal from the cancellation switch 22 is input to the left-turn-signal OR circuit 18a and the right-turn-signal OR circuit 18b, and the left-turn-signal OR circuit 18a and the right -turn-signal OR circuit 18b output the ON signals. On the other hand, the left-turn-signal limit switch 15a and the right -turn-s igna 1 limit switch 15b output the OFF signal. Therefore, the left-turn-signal FF 16a outputs the OFF signal from the first output pin Q1 and the ON signal from the second output pin Q2 so that the left- turn-signal lamp 9a will be extinguished in a case the light is on. In the same way, the right-turn-signal FF 16b outputs the OFF signal from the first output pin Q1 and the ON signal from the second output pin Q2 so that the right turn signal lamp 9b will be extinguished in a case the light is on.

With references to Fig. 4, a second embodiment is described hereafter. For this embodiment, the parts that are approximately the same as in the above-described first embodiment are omitted and only the parts that are different are described here. The embodiment wherein the turn signal switch 10 functions also as the cancellation switch 22 comprises two AND circuits in the electric circuitry thereof. TheANDcircuits comprise a left-turn-signal AND circuit 23a and a rightturn-signal AND circuit 23b. The left-turn-signal AND circuit 23a comprises a first input pin A for input of an output signal from the first output pin Q1 on the left-turn-signal FF 16a, a second input pin B for input of an output signal from the left-turn-signal limit switch 15a, and an output pin Y for output of computation result as an output signal to the lef t-turn-signal OR circuit 18a on reception of the input signals. In the same way, the right-turn-signal AND circuit 23b comprises a first input pin A for input of an output signal from the first output pin 01 on the left-turn-signal FF 16a, a second input pin B for input of an output signal from the rightturn- signal limit switch 15b, and an output pin Y for output of computation result as an output signal to the right-turn- signal OR circuit 18b on reception of the input signals.

In accordance with the structure described above, operations of the electric circuitry are now described. Entry of a turn direction through the turn signal switch 10 by the operator causes illumination of the leftturn-signal lamp 9a. In a case wherein the illuminating left-turnsignal lamp 9a is desired to be extinguished at the next step, the operator enters the left turn direction through the turn signal switch 10 again. This causes output of an ON signal from the left-turn-signal limit switch 15a to the left-turn-signal FF 16a and to the left-turn-signal AND circuit 23a. The set input pin S on the left-turn-signal FF 16a receives the ON signal from the left-turn-signal limit switch 15a while the reset input pin R receives the OFF signal from the left-turn-signal OR circuit 18a and, as the result, the first output pin Ql on the leftturn-signal FF 16a outpu, ts the ON signal while the second output pin Q2 outputs the OFF signal.

The first input pin A on the lef t-turn-signal AND circuit 236a receives the ON signal from the left-turn-signal FF 16a while the second input pin B receives the ON signal from the left-turn-signal limit switch 15a and the output pin Y outputs the ON signal. The ON signal that is output from the leftturn-signal AND circuit 23a is input to the left-turn-signal OR circuit 18a and the ON signal is output from the lef t-turn-signal OR circuit 18a. After output of the ON signal at the early stage, the OFF signal is continually output from the left-turn-signal limit switch 15a. This causes the set input pin S on the left-turn-signal FF 16a to receive the OFF signal, the reset pin R to receive the ON signal, the f irst output pin Ql on the left-turn-signal FF 16a to output the OFF signal and the second output pin Q2 to output the ON signal, and thus the leftturnsignal lamp 9a is forced to be extinguished.

That is, the left-turn-signal lamp 9a can be illuminated and extinguished by the turn signal switch 10- Although the illumination and extinguishment of the left-turn-signal lamp 9a have been. described above, the illumination and extinguishment of the right turn signal lamp 9b are approximately the same.

The illumination of the left-turn-signal lamp 9a and the left turn signal lamp 9b in the above includes continuous illumination and blinking illumination.

As described above in details, the first aspect of the invention enables extinguishment of the illuminating turn signal lamp by the first extinguishing means or by the second extinguishing means. That is, the operator needs not carry out the turn-signal extinguishing operation by himself, and thus the operator does not have to both illuminate and extinguish the turn signal lamps each time directly. Under this circumstance, accidents due to abstraction of attention by operations of both illuminating and extinguishing the turn signal lamps and failure in extinguishing the turn signal lamp are less liable to occur and moving operation and fork operation are carried out safely.

With use of the second extinguishing means, which can extinguish the left or right turn signal lamp after expiration of the predetermined duration of time from the input by the direction indicating means, and thus the illuminating right or left turn signal lamp is extinguished without fail by the time control.

The second aspect of the invention enables extinguish illuminating right or left turn signal lamp as the operator desires in such a case of incorrect direction indication. Since this enables extinguishing the right or left turn signal lamp through input operation by the operator, irrelevant to continuation, stop or expiration of time of turning operation of the steering wheel, safe and ensured extinguishment is available- - 16 The third aspect of the invention, which provide a structure wherein the direction indicating means is reset automatically, requires no manual operation for resetting the direction indicating means and saves time of the operator, thus ensuring safe moving operations and fork operations.

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Claims

CLAIMS:

A turn direction indicator for a vehicle comprising: a turn signal lamp for informing a steering direction of a vehicle; direction indicating means for illuminating the turn signal lamp according to an input operation by an operator; and first extinguishing means for detecting the steering direction of the vehicle and extinguishing the turn signal lamp by outputting a light-off signal when the steering direction becomes opposite to a direction of the turn signal lamp illuminated by the direction indicating means.
2. The turn direction indicator as claimed in claim 1, further comprising: second extinguishing means for extinguishing the turn signal lamp by outputting a light-off signal after expiration of a predetermined duration of time from a time at which the direction indicating means starts to illuminate the turn signal lamp.
3. The turn direction indicator as claimed in claim 1, further comprising: third extinguishing means for extinguishing the turn signal lamp forcibly by input operation of the operator.
4. The turn direction indicator as claimed in claim 1, wherein the direction indicating means has a structure of automatic reset to a neutral state after being tilted to the right or the left by the operator.
5. The turn direction indicator as claimed in claim 1, wherein the first extinguishing means detects a steering torque of a steering wheel to determine whether the steering direction becomes opposite to the direction of the turn signal lamp illuminated by the direction indicating means.
6. The turn direction indicator as claimed in claim 1, wherein the first extinguishing means comprises: a torque sensor for detecting a steering torque of a steering wheel; a discriminator for receiving signals from the torque sensor and discriminating the steering direction of the steering wheel; and a timer for starting time measurement on reception of signals from the discriminator, and the timer for outputting the light- off signal to extinguish the turn signal lamp after expiration of a predetermined duration of time.
7. The turn direction indicator as claimed in claim 2, wherein the second extinguishing means comprises:

a total timer for measuring the predetermined duration of time from the time at which the direction indicating means starts to illuminate the turn signal lamp.
S. A turn direction indicator for a vehicle comprising: a turn signal lamp for informing a steering direction of a vehicle; direction indicating means for illuminating the turn signal lamp according to an input operation by an operator; and second extinguishing means for extinguishing the turn signal lamp by outputting a light-off signal after expiration of a predetermined duration of time from a time at which the direction indicating means starts to illuminate the turn signal lamp.
9. The turn direction indicator as claimed in claim 8, further comprising:

third extinguishing means for extinguishing the turn signal lamp forcibly by input operation of the operator.
10. The turn direction indicator as claimed in claim 8, wherein the direction indicating means has a structure of automatic reset to a neutral state after being tilted to the right or the left by the operator.
11. The turn direction indicator as claimed in claim 8, wherein the second extinguishing means comprises: a total timer for measuring the predetermined duration of time from the time at which the direction indicating means starts to illuminate the turn signal lamp.
12. A turn direction indicator substantially as hereinbefore described with reference to any one of the accompanying drawings.

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