Abstract:
A transmitter-receiver system comprises one single transmitter (1) and numerous receivers (6) mounted in a housing (9) having vertically stacked compartments (10) for the receivers (6) and an upper compartment (11) for the transmitter (1) so that the latter can permanently support the whole system on a user&#39;s body.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention covers a system consisting of a transmitter and multiple receivers for radio communication. 
     2. Description of Related Art 
     Apart from long distance telecommunications, this invention concerns radiocommunication at sight; i.e. radiocommunications for direct instruction or correction of people operating under the direct control of an instructor or trainer (sports training, ski, horse-riding and swimming lessons, safety on sea, group excursions, work control, police actions etc.). In the radiocommunication at sight sector, a vast product range is already available on the market which have, however, numerous drawbacks. 
     The first of these disadvantages lies in the fact that all hitherto known systems are transceivers, which means that trainer and trainee, or instructor and pupil are both equipped with a transceiver set with a considerable purchase and investment cost and a far from negligible weight and volume to carry along. 
     The second drawback is that these transceiver sets can only be carried by hand so that they cannot be easily used by sportsmen or other people who need to have their hands free. Transceivers with headsets are also known, but this solution is rather cumbersome (since it requires an earpiece, microphone and antenna) and cannot always be used. Furthermore, these known transceiver types are battery-energized and these batteries have to be periodically replaced. 
     Even if they are fitted with rechargeable batteries, each set needs individual recharging which causes considerable inconvenience and loss of time. 
     Another disadvantage concerns the high purchase costs when a considerable number of transceiver sets are needed; their storage also becomes more difficult requiring more space, while handling and use may be troublesome. 
     SUMMARY OF THE INVENTION 
     This invention has the aim completely to eliminate the above disadvantages and to make available a low cost and functional transceiver system for radio communication. 
     According to a first characteristic of the invention, the transceiver set comprises one single transmitter and a multiple number (for instance ten) of receivers. Each component is thus greatly simplified, with much lower costs and less weight and volume to carry around. 
     According to a further characteristic of the invention, the transmitter and receivers are kept in a compact housing for storage and conveyance. 
     This is possible because of the particular miniaturization of the components having built-in antennas. The set is hooked onto a suspender of the instructor or trainer, who will then distribute the correct number of receivers to their pupils or trainees and pick them up again at the end of the training or lesson, to store them in their housing. 
     The receivers are placed inside earflaps or in caps, bonnets, safety helmets, for one ear only, so that the trainee&#39;s hands remain free. 
     According to an additional characteristic of the invention is the presence of contacts inside the housing for contemporaneous charging of all transmitter and receiver batteries. 
     These characteristics and others, which will be described herein, have made it possible to obtain a very simple, low cost, functional and handy system for telecommunication which can be easily stored and used, even by a variable number of users. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention in question is illustrated, in its practical implementation and exemplified preferential utilization, in the enclosed drawings, in which: 
     FIG. 1 and FIG. 2 respectively show a front and side view of the transmitter; 
     FIG. 3 and FIG. 4 respectively show a front and side view of the receiver; 
     FIGS. 5, 6 and 7 show perspective views of the various components of the housing; 
     FIG. 8 shows a perspective view of the transceiver set; 
     FIG. 9 shows an ear protecting band in which the receiver is fitted; 
     FIG. 10 shows a suspender around the neck housing the set in question; 
     FIG. 11 shows an other type of suspender by which the set in question is slung over the shoulder. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the above Figures, 1 represents a miniaturized transmitter with a built-in antenna, complete with a microphone 2 and two contacts 3 located on one side of the transmitter casing for battery recharging. 
     The casing of this transmitter 1 has two laterally transverse slots 4 for assembly on a housing 9 and a hook 5 at the back of the casing for securing the set on a suspender worn by a user. 
     Each receiver 6 is also miniaturized with a built-in antenna and has on one of its sides a loudspeaker 7 and on the other side two contacts 8 for battery recharging. 
     The housing 9 for the transmitter 1 and the receivers 6 is a box-shaped structure with numerous horizontal compartments 10 with through-holes one on top of the foregoing, for receiving the various receivers 6. A recess 11 at the top of the housing 9 receives the transmitter 1 and this recess 11 has on its side walls two opposite projecting horizontal ribs 12, which can enter into the slots 4 of the transmitter 1 so that the transmitter is installed by horizontal transverse insertion, whereby the transmitter can sustain the weight of the whole assembly by means of the hook 5, as shown for exemplification in FIG. 10. 
     Furthermore, the housing 9 has at the back a plate 13 provided with two vertical sets of conductor segments 14, 14&#39; which will coincide with the contacts 3 of the transmitter 1 and with the contacts 8 of the receivers 6 mounted inside the housing 9. 
     Each vertical set of lamellar contacts 14 or 14&#39; is parallel connected (short-dashed lines) and can be energized by a recharging set which may be either independent or incorporated, preferably in the lower portion of the housing 9. 
     Recharging may be from the mains or by light cells. 
     The housing is completed by a rear cover 15 fastened by screws or other means thereto. The container should be preferably in plastic material. 
     Based upon the above description, a transmitter-receiver assembly according to this invention is exemplified in FIG. 8, featuring a transmitter 1 and ten receivers 6, although any number of receivers will be possible according to need and application. 
     This assembly is properly sustained by an adjustable suspender 16 with buckles 17 to be hooked to a belt by clips 18. This suspender 16 slung around the neck (FIG. 10) or shoulder (FIG. 11) crosses the breast by means of a buckle fitted with an eyelet in which to secure the transmitter hook 5. Therefore, the whole assembly (FIG. 10) or the transmitter only (FIG. 11) may be sustained by the suspender, according to whether the housing can be located elsewhere. 
     If the individual who is transmitting has the whole assembly hanging from the suspender, delivery and retrieval of the receivers wil be much easier since they can be distributed and then back without any loss of time, even during lessons or training. 
     The various receivers are mounted at the user&#39;s ear with the aid of a headband 19 (FIG. 9) fitted with a pocket in which to place the receiver. Obviously, the receivers can also be kept in bathing caps (for swimming, water-polo etc.), helmets (motorbikes, soccer etc.) or in any other way, instead of in the headband, according to need. 
     It is clear that the receivers and transmitter shall both be water-tight if they are used in the water.