Background of the Invention
This invention relates to a system for informing the operator of a motor vehicle or the like of its operation time, and relates more particularly to such an operation time informing system for preventing operational accidents caused by fatigue of the operator due to excessive continuous operation time.
It is known that, in general, when an operator of a vehicle, such as a motor vehicle driver, has driven his vehicle continuously over a long period of time, the resulting fatigue gives rise to a drop in his attentive power and a dulling of his reflexes or to sleepiness, all of which increase the danger of an accident. In order to prevent such an accident, it is necessary for a driver to rest periodically.
However, since there has heretofore been no means of measuring driving time and notifying the driver of that time in a conventional motor vehicle, the only recourse for the driver has been to exercise care and remind himself to rest periodically.
Summary of the Invention
It is an object of this invention to provide an operation time informing system (hereinafter referred to simply as system) of a motor vehicle or the like, which system operates when the vehicle has been continuously operated for a preset limit time to inform the operator of that fact and suggest to him to rest and, in the case where he has taken a short rest which is less than the ncessary rest period, to count this time as continuous operation time without considering it as rest time, thereby to prevent operational accidents arising from fatigue of the operator.
According to this invention, briefly summarized, there is provided a system for informing the operator of a vehicle or the like of operation time of the vehicle, which system comprises: a first timer for setting a limit operation time period which starts to operate and to count time upon detecting starting of the vehicle driving operation; a second timer for setting a rest time period which starts to operate and to count time upon detecting stopping of the vehicle driving operation; warning means for generating and emitting a warning upon detection that counting of the limit operation time period set by the first timer has been completed after start of operation of the first timer; means for causing the warning means to become inoperative upon detecting that counting of the rest time period set by the second timer has been completed after start of operation of the second timer; and means for causing the operation of the first timer to continue when the vehicle operation is restarted before completion of counting of the rest time period set by the second timer after start of operation of the second timer.
The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description with respect to a preferred embodiment of the invention when read in conjunction with the accompanying drawings briefly described below.
Brief Description of the Drawings
In the drawings, FIGS. 1 through 8 are circuit diagrams showing the essential parts of one example of the system according to this invention and respectively indicating sequential steps in the operation thereof.
Detailed Description of the Invention
The example of the system illustrated in the FIGS. 1-8 drawings has first and second electric relays R.sub.1 and R.sub.2, a first electric timer T.sub.o for setting operation or driving time, a second electric timer T.sub.r for setting rest period, and a pilot lamp PL used as a warning device, which are mutually connected in parallel and, at the same time, are connected through a fuse F in series with a battery B mounted on a motor vehicle.
The first relay R.sub.1 is connected in series with an engine switch SW for closing and opening the engine ignition system of the vehicle. When this engine switch SW is closed, the relay R.sub.1 is connected in series with the battery B, and its relay coil (not shown) is energized. The relay R.sub.1 has a normally open contact (a-contact) S.sub.R1-a and a normally closed contact (b-contact) S.sub.R1-b. The second relay R.sub.2 has normally open contacts (a-contacts) S.sub.R2-a1 and S.sub.R2-a2. The timers T.sub.o and T.sub.r respectively have a normally open time limit contact (a-contact) S.sub.To-a and a normally closed time limit contact (b-contact) S.sub.Tr-b.
To the timer T.sub.o and relay R.sub.2 are respectively connected in series the a-contact S.sub.R1-a which closes when current is passed through the relay R.sub.1 and the a-contact S.sub.R2-a1 which is connected in parallel with the a-contact S.sub.R1-a and closes when current is passed through the relay R.sub.2. Furthermore, to these a-contacts S.sub.R1-a and S.sub.R2-a1 is connected in series the time limit b-contact S.sub.Tr-b which opens during a certain time period when a set time period of the timer T.sub.r has elapsed after start of its operation.
To the timer T.sub.r are respectively connected in series the a-contact S.sub.R2-a2 which is closed by passage of current through the relay R.sub.2 and the b-contact S.sub.R1-b which is opened by passage of current through the relay R.sub.1. Further, the time limit a-contact S.sub.To-a is connected in series with the pilot lamp PL, the contact S.sub.To-a closing during a certain time period when a set time period of the timer T.sub.o has elapsed after start of its operation. The timer T.sub.o is so set that its set operation time period is ordinarily of the order of 2 to 3 hours, while the timer T.sub.r is so set that its set rest time period is ordinarily of the order of 5 to 10 minutes.
The operation of the system of the above described organization according to this invention is as follows.
FIG. 1 indicates the state of the system wherein the engine switch SW is open prior to starting of the vehicle engine. In this case, the two relays R.sub.1 and R.sub.2 and the two timers T.sub.o and T.sub.r are all inoperative. Consequently, the a-contacts S.sub.R1-a, S.sub.R2-a1, S.sub.R2-a2, and S.sub.To-a are in open or "OFF" state, while the b-contacts S.sub.R1-b and S.sub.Tr-b are in closed or "ON" state.
When, from the above described state, the engine switch SW is closed, first current is passed through The relay R.sub.1 and the a-contact S.sub.R1-a is closed, while the b-contact S.sub.R1-b is opened as indicated in FIG. 2. When the a-contact S.sub.R1-a is thus closed, current is passed through the relay R.sub.2 connected in series thereto, whereby the a-contacts S.sub.R2-a1 and S.sub.R2-a2 are closed, and, at the same time, the timer T.sub.o starts its operation to count the operation time period.
When, with the system in this state, the driving of the vehicle is continued up to the time limit set by the timer T.sub.o, the time limit a-contact S.sub.To-a is closed by the operation of the timer T.sub.o as indicated in FIG. 3, and the pilot lamp PL is lit, thereby suggesting to the driver that he should rest. Accordingly, the driver can rest in conformance with this warning.
When, with the system in this state, the driver turns "OFF" the engine switch SW in order to rest, current to the relay R.sub.1 is cut off as indicated in FIG. 4, and the a-contact S.sub.R1-a is opened, while the b-contact S.sub.R1-b is closed. On the other hand, the supply of current through the relay R.sub.2 is continued by way of the b-contact S.sub.Tr-b and the a-contact S.sub.R2-a1, whereby the a-contact S.sub.R2-a2 is maintained in its closed state. Accordingly, simultaneously with opening of the engine switch SW, current is passed by way of the b-contact S.sub.R1-b and the a-contact S.sub.R2-a2 through the timer T.sub.r for setting the rest period, which thereupon begins counting the rest time period. Since the supplying of current through the timer T.sub.o is being continued during this operation, the pilot lamp PL is maintained in its lit state.
When, with the system in this state, the driver takes a rest up to the time limit set by the timer T.sub.r, the time limit b-contact S.sub.Tr-b is opened by the operation of the timer T.sub.r as indicated in FIG. 5. The supply of current to the timer T.sub.o is thereupon cut off, and the time limit a-contact S.sub.To-a is opened, whereby the pilot lamp PL is extinguished. The timer T.sub.o returns to its initial state prior to the start of counting. Simultaneously, the supply of current to the relay R.sub.2 is cut off, and the a-contacts S.sub.R2-a1 and S.sub.R2-a2 are opened. Consequently the supply of current to the timer T.sub.r is cut off, and the timer T.sub.r returns to its initial state prior to the start of counting. At the same time, the time limit a-contact S.sub.Tr-b is closed, and the system assumes the state indicated in FIG. 1.
In this manner, the pilot lamp PL continues to be lit until, after the driver turns off the engine switch SW, he has rested through at least the rest period set by the timer T.sub.r. Accordingly, in the case where the driver has rested only insufficiently, the pilot lamp PL is not extinguished but indicates that further rest should be taken. Thus, the pilot lamp PL has the double function of warning the driver that he has driven over the limit driving time and of warning him that he has not rested through the necessary rest period.
On the other hand, when, with the system in the state of continuous operation indicated in FIG. 2, the engine switch SW is opened prior to the end of the time set by the timer T.sub.o for setting the operation time, that is, when the driver takes a rest before the pilot lamp PL becomes lit as indicated in FIG. 3, the supply of current to the relay R.sub.1 is cut off, as indicated in FIG. 6, by the opening of the engine switch SW, and the a-contact S.sub.R1-a is opened, while the b-contact S.sub.R1-b is closed as shown. Current is thereupon passed by way of the b-contact S.sub.R1-b and the a-contact S.sub.R2-a2 through the timer T.sub.r, which thereupon starts to count the rest time period. Since, on the other hand, the supply of current via the time limit b-contact S.sub.Tr-b and the a-contact S.sub.R2-a1 through the timer T.sub.o is continued, the timer T.sub.o continues counting the operation time. That is, in this case, the rest period and the operation time are counted in parallel.
In the case where, from this state, the engine switch SW is closed before the timer T.sub.r has finished counting up, that is, in the case where the engine is restarted before the driver has had ample rest, current is supplied through the relay R.sub.1 by the switching on of the engine switch SW, and the a-contact S.sub.R1-a and the b-contact S.sub.R1-b are closed and opened, respectively, as indicated in FIG. 7. As a consequence, the supply of current to the timer T.sub.r is cut off, and the timer T.sub.r returns to its initial state prior to the start of counting. On the other hand, the timer T.sub.o continues to count, irrespective of whether or not the driver's rest is ample, until the driving limit time is reached. Thus, in the case where the driver has not rested sufficiently, the system does not consider that he has rested but deems that the driving is being continued. Then, when the timer T.sub.o finishes counting the driving limit time including the insufficient rest period, the time limit a-contact S.sub.To-a is closed similarly as in the aforedescribed case, and the pilot lamp PL becomes lit to indicate a warning. Thus, driver safety is assured.
On the other hand, in the case where, from the state indicated in FIG. 6, the driver has had an ample rest, and the period set by the timer T.sub.r ends, the action of this timer T.sub.r first causes the time limit b-contact S.sub.Tr-b to be opened as indicated in FIG. 8. Consequently, the supply of current to the timer T.sub.o is cut off, and the timer T.sub.o returns to its initial state prior to the start of its counting. Simultaneously, the supply of current to the relay R.sub.2 is also cut off, and the a-contacts S.sub.R2-a1 and S.sub.R2-a2 indicated as being in the closed state in FIG. 8 are opened. As a result, the supply of current to the timer T.sub.r is cut off, the timer T.sub.r is returned to its initial state prior to the start of its counting, and at the same time the time limit b-contact S.sub.Tr-b is closed. Thus the entire circuit is returned to the state indicated in FIG. 1.
As described above, when the pilot lamp PL becomes lit, the driver can readily see that he has driven more than the driving limit time, and, also during his rest period, the driver can tell that he has not had an ample rest by observing the continued lit state of the pilot lamp. Thus, driving accidents due to causes such as a drop in the driver's attentive power, a dulling of his reflexes, or his becoming sleepy can be prevented. Furthermore, since insufficient rest is counted as driving time without being considered as rest, accidents can be prevented with even greater effectiveness. In addition, because the circuit of the system according to this invention is of simple organization, the system has high reliability yet can be produced to sell at a low price.
While, in the above described example of practice, a pilot lamp PL is used to inform the driver of limit times, another kind of warning means such as a buzzer may be used instead or in addition.
While the system of this invention has been described above with respect to an example thereof applied to a motor vehicle, it will be obvious that the system can be applied with equal effectiveness to other vehicles and machines to be operated over long periods.