Patent Publication Number: US-2007105601-A1

Title: Speaker unit for a communication system

Description:
BACKGROUND OF THE INVENTION  
      This invention relates to communications systems and, in particular, to communication systems for use with protective clothing for persons exposed to biochemical hazards.  
      Communications systems have been developed for persons wearing protective clothing adapted for biochemical hazards. Such persons typically wear protective face masks which inhibit normal speech communication with adjacent people. One approach has been to provide persons wearing such clothing with throat microphones or facemask microphones connected to chest-mounted speakers. The persons wearing the protective clothing can therefore be heard by adjacent people.  
      However, it is often desirable for people wearing such protective clothing to communicate with more remote persons by way of two-way radios or other RF devices. For this reason the chest-mounted speakers may have switches which are actuated so that signals from the microphone are routed to either the speaker or the RF device. In the past however it has been awkward to actuate the switches, particularly using protective gloves typically included with the protective clothing.  
      U.S. patent application No. 2002/0107053 to Petez, published Aug. 8, 2002, discloses a push to talk (PTT) transceiver that includes a mount assembly with a shell and a speaker/mike assembly. The speaker/mike assembly includes a speaker and a microphone, which are both contained in the shell. The PTT transceiver also includes a two-way radio with a manually operated PTT switch. When the switch is operated, the speaker is not energized and sounds picked up by the microphone are broadcast to other transceivers. When the PTT switch is not operated, any sound at the microphone will not be transmitted over radio waves, but the speaker will generate sounds for the ear representing radio waves that have been detected by the two-way radio.  
      U.S. Pat. No. 4,491,699 to Walker discloses a dual communication system including a mask microphone for use by a wearer of a protective facemask. An output signal from the microphone is communicated to both a speaker system for local, audible broadcast and to a transmitter for remote broadcast by radio signal. A jack plugged into a switching jack permits communication of the open signal from the mask microphone to the transmitter, while simultaneously providing the open signal to the speaker system. A selector switch selectively curtails radio transmissions from the transmitter, while still permitting the user to receive radio signals by the receiver of the transceiver.  
      U.S. Pat. No. 5,566,362 to Bauer discloses a voice transmission system for a protective face mask which includes a voice transmitter attached to an external portion of the face mask. The transmitter includes a microphone which converts the sound energy from the wearer of the face mask into an electrical signal that the transmitter communicates via short-range radio signal to a receiver.  
      U.S. Pat. No. 5,990,793 to Bieback discloses an integrated safety and communication system for attachment to a standard type of firefighter&#39;s face mask. The communication system includes a transceiver, a speaker, an electronics package, which includes an audio amplifier, and an on/off switch to enable or energize the amplifier-speaker unit. There is also a transceiver for communication with a command post transceiver.  
     SUMMARY OF THE INVENTION  
      According to one aspect of the invention there is provided a speaker unit for a communication system. The unit includes a housing with a loudspeaker being mounted on the housing. A grill is mounted on the housing over the loudspeaker. A switch is mounted on the housing. The grill operatively engages the switch whereby manually contacting the grill operates the switch. In one example the housing has a front and the grill is mounted on the front of the housing. The grill is movable to operate the switch by manually pushing the grill.  
      According to another aspect of the invention there is provided a communication system with a microphone, an RF transmitter and a speaker unit. The speaker unit includes a housing, a loudspeaker mounted on the housing, a grill mounted on the housing over the speaker and a switch mounted on the housing. The grill operatively engages the switch whereby manually contacting the grill operates the switch. Conductors connect the microphone, the RF transmitter and the speaker unit. Operation of the switch by movement of the grill connects the microphone alternatively to the RF transmitter or the loudspeaker.  
      According to a further aspect of the invention there is provided a speaker unit for a communications system. The unit includes a housing having a front and a back. The front has a plurality of spaced-apart recesses. A circuit board is fitted to the back of the housing. There is a push to talk switch mounted on the circuit board. There is a grill having a plurality of outwardly extending tabs. The tabs slidably engage the recesses of the housing to permit the grill to move in a direction extending between the front and the back of the housing. One of the tabs of the grill contacts the push to talk switch, whereby pushing the grill towards the back of the housing actuates the switch. There is an annular retainer fitted over the grill to retain the grill on the housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Referring to the drawings:  
       FIG. 1  is a block diagram of a communication apparatus according to an embodiment of the invention;  
       FIG. 2  is a front view of the housing for the chest speaker assembly thereof;  
       FIG. 3  is a sectional view taken a long line  3 - 3  of  FIG. 2 ;  
       FIG. 4  is an exploded view of the chest speaker assembly;  
       FIG. 5  is a front view of the chest speaker assembly with the push-to-talk switch in the deactivated position;  
       FIG. 6  is a sectional view taken a long line  6 - 6  of  FIG. 5 ;  
       FIG. 7  is a view similar to  FIG. 5  with the switch in the activated position;  
       FIG. 8  is a sectional view taken a long line  8 - 8  of  FIG. 7 ; and  
       FIG. 9  is a fragmentary perspective view of the person wearing protective clothing and fitted with a communication apparatus according to an embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to the drawings, and first to  FIG. 9 , this shows a person  12  wearing a biochemical suit  14  of the type worn during biochemical emergency situations. For example the person could be employed to deal with patients who have been exposed to a biochemical hazard and to decontaminate such patients before they are admitted to a hospital where they could potentially contaminate other patients or hospital staff as well as the hospital premises. In such a situation the person  12  is protected from the biochemical hazard by the suit  14  including a face mask  16 . However it is difficult for the person to communicate with patients and personnel within the hospital while wearing the suit  14 , particularly with the mask  16 .  
      For this reason communications systems have been developed which include a throat mike  20  of the well-known type available, for example, from Con-Space Communications at www.con-space.com as Part No. 1303-02-011. Alternatively, other types of throat mikes or other transducers capable of converting the human voice to suitable electrical signals could be substituted.  
      The person  12  is shown wearing an earpiece speaker  22  for monitoring incoming messages from a two-way radio  27 , shown in  FIGS. 1 and 9 , or another RF device. There is also a chest speaker assembly  24  which includes a chest speaker  26 , shown in  FIG. 1 , whereby the person  12  can communicate with nearby persons via the throat mike  20 . The earpiece speaker  22  is connected to the throat mike by conductors  30 . Conductors  32  connect the throat mike to the chest speaker assembly. Conductors  34 , shown in  FIGS. 1 and 9 , connect the chest speaker to the two-way radio  27 . It should be understood that other wiring configurations are possible or the various devices could be connected by wireless communications systems such as Bluetooth. As described thus far, the apparatus is generally conventional and accordingly is not described in more detail.  
      In conventional apparatuses of the general type the chest speaker assembly is provided with a PTT switch  70  which enables the person to communicate either to adjacent persons via speaker  26  or to, for example, remotely located persons such as other hospital personnel, via the two-way radio  27 . However it is cumbersome for the person to operate such a switch while wearing protective clothing, particularly while wearing gloves  40 .  
      The invention overcomes problems associated with prior art apparatuses by including an improved chest speaker assembly  24  as shown in better detail in  FIGS. 2-8 . The assembly includes a housing  44  which in this embodiment is of plastic although alternatively it could be of metal or other materials. The housing includes a generally rectangular rear cavity  46  with a recess  48  extending about the periphery thereof for receiving a PC board  50 . A circular cavity  54  extends inwardly from the cavity  46  and receives the speaker  26 . The housing has a circular aperture  60  which exposes the speaker to speaker grill  62  having a plurality of apertures  64  to allow acoustical signals to be transmitted to adjacent persons. This general arrangement is common in earlier speaker assemblies.  
      The speaker assembly  24  however is unique in that speaker grill  62  is used to activate push to talk (PTT) switch  70  which in this example is mounted on the PC board  50  as shown in  FIGS. 4, 6  and  8 . The grill in this example has a generally circular body  72  with a plurality of tabs extending radially outwards therefrom. Three of these tabs are visible in  FIG. 8  including top tab  80 , bottom tab  82  and one side tab  84 . The grill has a second side tab extending on the side opposite tab  84  although not shown in the drawings.  
      The housing has generally rectangular recesses  90 ,  92 ,  94  and  96  for respectively receiving the tabs  80 ,  82 ,  84  and the other side tab not shown. The recesses are larger than the tabs, allowing movement of the grill in a direction extending from front  98  to rear  100  of the housing. An annular grill retainer  102  is press fitted into a complementary-shaped recess  104  on the housing to prevent the grill from being dislodged from the housing, but allowing limited movement of the grill between the retainer  102  and face  110  of the housing.  
      The tab  82  is provided with a dimple  120  having a concave surface facing PTT switch  70  and fitting over the switch. When the grill is released, as shown in  FIGS. 5 and 6 , the switch is deactivated and acoustical signals from the throat mike  20  are routed to the speaker  26 . However when the person wishes to communicate with others via two-way radio  27  shown in  FIG. 1 , the person presses on the grill  26  as illustrated in  FIG. 9  and by arrow  130  in  FIG. 8 . This causes the grill, in particular tab  92  thereof, to press the PTT switch  70  at dimple  120 . The switch then routes electrical signals from the throat mike to the two-way radio  27  shown in  FIG. 1 .  
      It will be understood by someone skilled in the art that many of the details provided above are by way of example only and are not intended to limit the scope of the invention which is to be determined with reference to the following claims.