Abstract:
A 2-way radio system for use by a driver of a vehicle such as a motorcycle, enables operation of the PTT (push-to-talk) switch to transmit voice communications, without requiring the driver to raise his/her hand to a PTT switch button on the 2-way radio and without requiring a cable connection. A self-contained separate PTT control unit ( 40 ) lies at the driver&#39;s finger for operation by the finger without taking the driver&#39;s hand off the steering bar ( 12 ). During operation, the unit transmits a short range radio signal ( 70 ) to a PTT receiver ( 90 ) on the 2-way radio to switch the radio to the transmit mode. The PTT control unit can be mounted on the driver&#39;s finger or on the steering bar.

Description:
BACKGROUND OF THE INVENTION 
     A 2-way radio is usually constructed so it is always in a receive mode to receive signals that drive a speaker, except when a PTT (push-to-talk) switch is being activated. During the time when the PTT switch is actuated, the radio only transmits signals representing sound picked up by a microphone. The 2-way radio is commonly contained in a single case with a projecting antenna, so a person must lift his/her hand to reach the PTT switch on the case to depress it. 
     Drivers who drive vehicles under difficult conditions, such as a bicycle or motorcycle driver manipulating in heavy traffic, generally should not be encouraged to take his/her hands off the steering bar to press the PUT switch. Since the 2-way radio is commonly mounted on the driver&#39;s waist, one solution has been to extend a cord from the 2-way radio to a switch box mounted more conveniently on the person, such as on the person&#39;s chest, or in a vehicle such as a police car. This still requires the driver to take a hand off the steering bar and to find and depress the PTT switch. Also, the presence of a cable can add danger to the driver, as when the cable becomes snagged on a stationery object as the driver moves by. Apparatus for operating a 2-way radio to switch to a transmit mode, which avoided the need for the driver to take a hand off the steering bar to find and depress a switch, and which avoided the presence of a PTT cable extending from the radio, would be of value. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment of the present invention, a radio system is provided for use by a vehicle driver, which enables the driver to switch and maintain the radio in the transmit mode by maintaining activation of a manual PTT (push-to-talk) switch, which avoids requiring the driver to take his/her hand off a steering bar and which avoids the need for a long cable extending from the radio. A PTT control unit includes a switch positioned for activation by a finger of the driver while the driver continues to hold the steering bar. The PTT control unit includes a transmitter that transmits a short range radio signal to a detector on the 2-way radio or located on a speaker microphone, to switch the 2-way radio to the transmit mode. 
     The PTT control can be mounted directly on the person&#39;s hand, with a manually-activatable switch lying at the inside of a finger of the driver. This allows the driver to operate the switch by pressing it firmly against the steering bar of a vehicle. Alternatively, the PTT control can be mounted on the steering bar of the vehicle with the switch positioned so it lies adjacent to a finger of the driver when the driver holds the steering bar during normal vehicle driving. This allows the driver to easily depress the switch without removing his/her hand from the steering bar. 
     The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of the radio system of the present invention, showing a 2-way radio mounted on a motorcycle drivers a control mounted on the driver&#39;s hand, and also showing a remote station. 
     FIG. 2 is a simplified schematic view of the PTT control of FIG.  1 . 
     FIG. 3 is a side view of the PTT control of FIG. 2, shown worn on the finger of the vehicle driver. 
     FIG. 4 is a view taken on line  4 — 4  of FIG.  3 . 
     FIG. 5 is a block diagram of a 2-way radio of the system of FIG.  1 . 
     FIG. 6 is a side view of the PTT control of FIG. 3, but shown mounted on a vehicle steering bar. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a radio system  10  for use by a vehicle driver D who has hands H lying on a steering bar  12  of a vehicle  14 . The particular illustrated vehicle is a low power motorcycle or motor scooter, such as the type that is commonly used to drive through heavy traffic in cities. The radio system includes a 2-way radio  20  that includes a main part  21  mounted on the driver&#39;s waist and a speaker-microphone set  30  on the upper chest or on an epaulet of the driver. In some cases, a speaker  24  and microphone  25  of the type illustrated, are provided. The main part  21  may have a belt clip for mounting on the driver&#39;s belt. In any case, the main part  21  (and the microphone and speaker) are mounted away from the hands H of the driver, and usually away from the arms A of the driver. The speaker of the set  30  is energized by signals  26  transmitted by another station  28  which may be located more than one mile from the vehicle. The 2-way radio is normally in a receive mode, but can be temporarily switched to a transmit mode, wherein it receives voice signals from a microphone  30  and transmits radio signals  32  modulated by the voice signals picked up by the microphone of set  30 , to the remote station  28 . 
     The radio is of a type that has PTT (push-to-talk) capability; that is, it transmits signals representing those picked up by the microphone of set  30 , only during the period when a PTT switch is being operated. In the past, the PTT switch was located on the 2-way radio main part  21  or on a speaker microphone attached to the radio. This would require the vehicle driver to take a hand off the steering bar, find the PTT switch, and keep that switch depressed so long as the driver wishes to talk. This can lead to dangerous conditions, because the driver may feel impelled to continue talking despite the need for both hands on the steering bar  12  to steer the vehicle through dangerous traffic. 
     In accordance with the present invention, applicant provides a PTT control unit  40  which is located on or beside one of the driver&#39;s hands H. FIG. 3 shows an example where the PTT control unit  40  is mounted on a finger F, such as the index finger, of the vehicle driver, by a finger mount in the form of a band  42  that encircles the index finger. The PTT control unit includes a switch  44  that is exposed at the inner inside I of the person&#39;s finger, with the exposed area  46  lying close to the steering bar  12  of the vehicle. The driver can press the exposed switch activating area  46  against the steering bar  12  to operate the switch while keeping his/her hand on the steering bar  12 . When the switch is operated, it allows a battery  50  to energize a very small and short range radio transmitter  52  which transmits, through an antenna  54 , a PTT signal which is detected by the main part  21  of the 2-way radio to switch it. The frequency of the radio output of the unit  40  is preferably different from that of the remote station. 
     FIG. 2 shows that the switch  44  includes a snap dome  60  which can be depressed by firm pressure (e.g. a force of 2 pounds) until it snaps to the position  60 A wherein it contacts a trace  62  on a circuit board  64  until the continuing pressing force (e.g. ½ pound) is removed. The periphery of the dome engages another trace  66  on the circuit board. When the circuit is closed by depressing the dome to position  60 A, it allows current from the battery  50  to flow through the oscillator transmitter  52 , so the oscillator-transmitter  52  generates a radio frequency PTT signal  70  that is transmitted by the antenna  54 . 
     The PTT control unit  40  is a very short range radio transmitter, which may be similar to the type commonly found on keychains to lock and unlock vehicle doors and alarms, or to open garage doors or gates. However, the unit  40  requires a range of no more than one meter. A wide variety of circuits can be used, including a circuit that transmits a pulse when the switch  44  is first closed, and which delivers a different pulse when the switch is opened, to conserve the power of the battery during the period when the driver is transmitting his speech. In FIG. 2, the group of pulses  67  indicates the beginning of a switch to the transmit mode while the group  69  represents the end of the transmission. The output of the transmitter oscillator  52  may include signals at a few frequencies or modulated signals that represent a code. 
     FIG. 5 is a simplified view of the circuitry of the 2-way radio  20  that is mounted on the vehicle driver&#39;s helmet. The radio has a diplex  71  that can transmit and receive over the same antenna  72 . In the receive mode, which the radio is usually in, signals from the diplex  71  are demodulated by a demodulator circuit  74 , to produce audio frequency signals. The audio signals are transmitted through a PTT-controlled switch  76  and energize a speaker  24  of a headphone (or the speaker of a speaker microphone set) that can be heard by the vehicle driver. When the PTT-controlled switch is switched to the transmit mode, voice signals detected by the microphone  25  are transmitted through the switch  76  to a modulator  80  which modulates the output of an oscillator  82  according to the voice signals. The modulated signals drive the diplex  71 , so as to transmit signals to another station. Most of the circuitry of the 2-way radio such as the antenna  72 , diplex, various amplifiers (not shown) and a battery, are mounted on the main part  21  of the radio. 
     The 2-way radio includes PTT circuitry  83  by which the remote PTT control unit  40  determines the state of the 2-way radio. The circuitry includes the PTT-controlled switch  76  and a PTT detect circuit  90 . The PTT-controlled switch  76  includes a switch control  84  that controls two switch parts indicated at  86  and  88 . When the PTT detect circuit, or radio receiver circuit  90 , receives a first PTT signal  70  from the PTT control unit  40  of FIGS. 2 and 3, the PTT detect circuit  90  delivers a signal to the switch control  84  to switch the PTT-controlled switch part  76  to the transmit mode, wherein the switch  88  is closed and the other one  86  is opened. Also, the diplex  70  is switched. It is noted that an auxiliary PTT switch  92  can be provided, so that if the PTT control unit  40  is not operating, the driver can still transmit signals to the remote station. 
     The use of a very low powered radio transmitter in the PTT control unit  40  enables control of the 2-way radio while the vehicle driver D keeps both hands on the steering bar  12 . The use of a radio transmitter in the PTT control unit, avoids the need for a cable to extend from the 2-way radio  20  to the PTT control  40  on the hand of the driver. Such a cable, with a length of more than one-half meter, would present a danger to the driver, where the driver is directly exposed to the environment, as in the case of a motorcycle or bicycle. Although such a cable may be tied at several places to the driver&#39;s body, there is a possibility that a length of the cable will become loose and could snag on objects in the environment, creating danger for the driver. Also, such a cable would be cumbersome. By eliminating such a cable, applicant provides a remote control without introducing such hazard. 
     There are a large number of vehicles in situations where a vehicle driver should keep both hands continually on the steering bar. Motorcycle and bicycle riders whose steering bar may be referred to as a handlebar, especially those who travel through crowded city streets or policemen while chasing a vehicle, are examples. Drivers of race vehicles or police cars, where the steering bar may be curved to form a “steering wheel” provide another example, whether the vehicle travels on land or is a boat that travels on water. Operators of other equipment also may require both hands on a steering bar while answering a call. 
     In FIG. 3, the vehicle driver can mount the PTT control unit  40  on a finger such as an index finger, and can continue to grasp the steering bar  12  with his thumb and other fingers. The driver can press the index finger so the exposed switch actuation area  46  is pressed against the steering bar to operate the switch  44 . FIG. 6 shows another mounting arrangement, where the PTT control  40 A has been mounted on the steering bar  12 . In that case, the driver&#39;s finger F is used to push against the exposed switch actuation area  46  by pressing the driver&#39;s finger against the switch  44 . FIG. 6 shows the tip of the finger pressing against the switch area  46 , although other joints of the finger can be used, such as the joint closest to the palm (especially if the driver wears a ring) or the middle joint of the finger. In actuality, a flexible covering can be used to cover the switch  44  to prevent corrosion and damage, with an additional cover over the battery  50 , transmitter  52  and antenna  54 . There is some advantage is mounting the PTT control  40 A on the steering bar  12 , in that it avoids weight on the driver&#39;s hand. However, applicant generally prefers that the control be mounted on the driver&#39;s finger, as in FIG. 3, so the switch is available to be operated even when the driver leaves the vehicle or is operating other controls of the vehicle. Most fingers and steering bars have a diameter of about one inch (0.5 inch to 2 inches), and the strap-like mount  56  in FIG. 6 and 42 in FIG. 3 are constructed to mount on such a cylindrical object. 
     Thus, the invention provides a radio system for use by a vehicle driver, which includes a 2-way radio having PTT (push-to-talk) capability, which enables the driver to switch to the transmit mode while keeping his/her hands on the steering bar even though the radio is (the main part  21 ) mounted more than a foot away form the hands such as on the driver&#39;s waist, and without the danger and cumbersomeness that a cable connection to a remote PTT switch would entail. This is accomplished by providing a PTT control unit that can be mounted to lie adjacent to the fingers of one of the driver&#39;s hands when the driver is grasping a steering bar of the vehicle, with the PTT control unit constructed to transmit a radio PTT signal to the 2-way radio to switch the radio to the transmit mode. The PTT control unit is preferably mounted on a driver&#39;s finger, although it can be mounted on the steering bar of the vehicle. 
     Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art, and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents.