Abstract:
A microphone-speaker assembly includes a housing, a microphone, a speaker, and a push-to-talk switch. The housing supports the speaker for movement between a first position in which the switch is not activated and a second position in which the switch is activated. The switch is located in a water resistant chamber along with a circuit board. The speaker moves toward the circuit board when it moves from the first position to the second position. A seal supports the speaker for movement between the first and second positions. A method of activating a microphone in a microphone-speaker assembly includes the steps of applying force to a speaker of the assembly, and moving the speaker thereby to activate the switch thereby to activate the microphone. The speaker moves relative to a push to talk switch, deforming a resilient membrane that helps to form a water resistant chamber in the assembly.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to a microphone-speaker assembly. In particular, the invention relates to a lapel unit, for example for connection with a user-mounted walkie-talkie, that includes a speaker, a microphone, and a push to talk switch for activating the microphone. The invention can be used with any 2 way radio that supports a remote lapel mic. This includes vehicle mounted radios and communications systems.  
       BACKGROUND OF THE INVENTION  
       [0002]     Traditionally, lapel units for connection with a user-mounted walkie-talkie include a speaker, a microphone, and a push to talk switch for activating the microphone. The switch is often relatively small and thus may be difficult to locate by a user wearing gloves, for example. In addition, the switch may be located on a side or corner of the unit which is not always quickly and readily located by the user.  
       SUMMARY OF THE INVENTION  
       [0003]     The present invention relates to a microphone-speaker assembly that includes a housing, a microphone, a speaker, and a push-to-talk switch. The assembly may be for use as a lapel unit to be connected with a user-carried transceiver. The housing supports the speaker for movement between a first position in which the push-to-talk switch is not activated and a second position in which the push-to-talk switch is activated. The housing at least partially defines a water resistant chamber, and the push-to-talk switch is located in the water resistant chamber along with a circuit board. The speaker moves toward the circuit board when it moves from the first position to the second position. The assembly preferably includes a seal that supports the speaker for movement between the first position and the second position.  
         [0004]     The invention also relates to a method of activating a microphone in a microphone-speaker assembly. The method includes the steps of applying force to a speaker of the assembly, and moving the speaker thereby to activate the switch thereby to activate the microphone. The speaker moves relative to a push to talk switch, deforming a resilient membrane in the assembly. The resilient membrane helps to form a water resistant chamber in the assembly. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]      FIG. 1  is a schematic illustration of a microphone-speaker assembly in accordance with the invention, being worn by a user and connected with a walkie-talkie;  
         [0006]      FIG. 2  is an enlarged perspective view of the microphone-speaker assembly of  FIG. 1 ;  
         [0007]      FIG. 3  is an exploded perspective view of the microphone-speaker assembly of  FIG. 1 ;  
         [0008]      FIG. 4  is an assembled sectional view of the microphone-speaker assembly of  FIG. 1 ; and  
         [0009]      FIG. 5  is an exploded sectional view of the microphone-speaker assembly of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0010]     The present invention relates to a microphone and speaker assembly and, in particular, to a microphone and speaker assembly that is suitable for use as a lapel unit connected to a transceiver, such as a walkie-talkie. The invention is applicable to microphone and speaker assemblies of varying constructions. As representative of the invention,  FIG. 1  illustrates a microphone and speaker assembly  10  in accordance with a first embodiment of the invention.  
         [0011]     The assembly  10  includes a housing  12 . The housing  12  includes a base  20  and a cover  30 . The base  20  is preferably molded as one piece from a suitable material, such as plastic.  
         [0012]     The configuration of the base  20  is adapted to support and enclose other components of the assembly. The base  20  is generally bowl shaped and includes a flat back wall  22  and a side wall  24  that extends upward from the back wall to form a partially closed space. A cable  26  extends from the base  20  and is connectable with a transceiver  28 , such as a walkie-talkie.  
         [0013]     The cover  30  is preferably molded as one piece from a suitable material, such as plastic. The configuration of the cover  30  is adapted to enclose, together with the base  20 , the other components of the assembly  10 .  
         [0014]     The cover  30  is generally bowl shaped, with a flat front wall  32  and a curved side wall  34  that extends from the front wall towards the base  20 . A circular speaker grill opening  36  is defined within the front wall of the cover  30 . The opening  36  is centered on an axis  38 . The cover  30  has an inner surface  40  facing towards the base  20  and an outer surface  42  facing outward from the base.  
         [0015]     The side walls  32  and  22  of the cover  30  and the base  20 , respectively, are complementary with each other. Thus, when the cover  30  and the base  20  are assembled together, the partially closed spaces of both the cover and the base combine to form one closed space that encloses, or houses, the other components of the assembly  10 . The housing  12  includes a gasket  44  ( FIG. 4 ) located between the cover  30  and the base  20  to help form a water resistant seal in the housing.  
         [0016]     The cover  30  and the base  20  are secured to each other by fastening means not shown. Several methods of assembling the base  20  and cover  30  together could be used, such as glue, screws, interengaging tabs and slots, etc.  
         [0017]     The lapel microphone-speaker assembly  10  also includes a support ring  50 . The support ring  50  is preferably molded as one piece from a suitable material, such as plastic. The support ring  50  could also be constructed from several pieces that are assembled together.  
         [0018]     The support ring  50  includes an annular seat  52  defining a central opening  54 . The central opening  54  is coaxial with the speaker grill opening  36  in the front wall  32  of the cover  30 . The seat  52  of the support ring  50  has a support surface  58  facing outward from the base  20  when the support ring is mounted on the base  20 . A groove  59  with a rectangular cross-sectional configuration is defined within the support surface  58  of the annular seat  52 .  
         [0019]     The support ring  50  also includes a plurality of support members in the form of posts  56  that project downward from the annular seat  52  towards the back wall  22  of the base  20 . The posts  56  engage the back wall  22  of the base  20  and support the annular seat  52  at a distance from the back wall of the base. The posts  56  may engage in sockets (not shown) in the back wall  22  of the base  20 , or be otherwise connected to the base. The support ring  50  shown in the illustrated embodiment includes six posts  56 , although different numbers, cross-sectional shapes and configurations of support members could be used. Additionally, other methods of supporting the annular seat  52  on the base  20  could be used. For example, the functions of the support ring  50  could be provided by the base  20  itself.  
         [0020]     The assembly  10  also includes a circuit board  60 . The circuit board  60  is a printed circuit board  60  and includes various electrical circuitry (described below). The circuit board has an upper surface  62  facing away from the back wall  22  of the base  20  and an opposite lower surface  64  facing towards the back wall of the base. The circuit board  60  is mounted, by fastening means not shown, on the back wall  22  of the base  20 , below the annular seat  52  of the support ring  50 , in a position generally aligned with the central opening  54  of the support ring  
         [0021]     A push-to-talk switch  66  is located on the circuit board  60 . The push-to-talk switch  66  is located on the upper surface  62  of the circuit board  60 , facing away from the back wall  22  of the base. The push-to-talk switch  66  is aligned with and accessible through the central opening  54  of the support ring  50 . The switch  66  may be located on the axis  38 . Many different types of electrical switches could be used as the push-to-talk switch  66 , such as a dome switch, etc.  
         [0022]     The assembly  10  further includes a speaker  70 . In the illustrated embodiment the speaker  70  is a water resistant cone speaker, although other types of speaker could be used. The speaker  70  has a generally frustoconical shape centered on the axis  38 . Because of its frustoconical configuration, the speaker  70  has a wide end  72  and a narrow end  74 . The speaker  70  includes a magnet and voice coil assembly  76  at its narrow end. The speaker  70  is electrically connected with the circuit board  60  as shown schematically at  78  in  FIG. 4 .  
         [0023]     The speaker  70  also includes a bowl shaped frame  80  made of suitable metal or plastic material. The speaker frame  80  includes a rim  82  and supports the magnet and voice coil assembly  76 .  
         [0024]     The assembly  10  also includes a seal  90 . The seal  90  is preferably molded as one piece out of a suitable deformable material, such as rubber or another elastomeric material. As described below, the seal  90  cooperates with the base  20  and the cover  30  to form a water resistant chamber in the housing  12 .  
         [0025]     The seal  90  is generally bowl shaped and is adapted to closely surround the speaker  70 . The seal  90  could be shaped or configured in different ways to enclose and support whatever speaker  70  is chosen for the assembly  10 . The seal  90  has a lower portion  92  adapted to enclose and support the magnet assembly  76  of the speaker  70 . The lower portion  92  of the seal  90  includes a flat, circular back wall  98  centered on the axis  38 , and a side wall  100  that extends upward from the back wall.  
         [0026]     A central portion  102  of the seal  90  includes a side wall  104  that extends radially outward from the side wall  100  of the lower portion  92  and then ramps upward in a direction axially away from the base  20  and radially outward away from the axis  38 . The side wall  104  of the central portion  102  is adapted to follow the profile of the speaker frame  80  and to mimic the generally frustoconical shape of the speaker  70 .  
         [0027]     The seal  90  has an upper portion  106 . The upper portion  106  of the seal  90  includes a side wall  108  that extends axially upward from the side wall  104  of the central portion  102 . The seal  90  has a flat, annular rim  110  that extends from the upper portion  106  of the seal. An inner portion  112  of the rim  110  extends radially inward from the upper portion  106  of the seal  90 , in a direction toward the axis  38 . The inner portion  112  of the rim  110  defines a circular opening  114  in the seal  90  that is centered on the axis  38 . An outer portion  116  of the rim  110  extends radially outward from the upper portion  106  of the seal  90 .  
         [0028]     Both the inner and outer portions  112  and  116  of the rim  110  have an outer surface  120  facing away from the base  20  and an inner surface  122  facing toward the base. An annular lip  124  is formed on the bottom surface  122  of the outer portion  106  of the seal rim  110 . The lip  124  extends from the seal rim  110  in a direction parallel to the side wall  108  of the upper portion  106  of the seal  90 . The lip  124  is received within the annular groove  60  on the seat  52  of the support ring  50 .  
         [0029]     The seal  90  is thus supported on the annular seat  52  of the support ring  50 , at a distance from the base  20 . The speaker  70  fits within the seal  90  and is supported and enclosed by the seal. A gap is defined between the speaker rim  82  and the inner portion  112  of the rim  110  of the seal  90 . A gap  128  is defined between the back wall  98  of the lower portion  92  of the seal  90  and the push-to-talk switch  66  located on the upper surface  62  of the circuit board  60 .  
         [0030]     The assembly  10  also includes a speaker grill  130 . The speaker grill  130  is preferably molded as one piece out of a suitable material, such as plastic, fiberglass or metal. The speaker grill  130  has a flat or domed, circular front wall  132  centered on the axis  38 . A plurality of holes or other shaped openings  134  are defined in the front wall  132  to permit sound waves projected from the speaker  70  to travel outward from the assembly  10 .  
         [0031]     The speaker grill  130  has an outer peripheral flange  136 . The flange  136  of the speaker grill  130  is secured in the gap between the speaker rim  82  and the inner portion  112  of the rim  110  of the seal  90 . When the seal  90 , speaker  70  and speaker grill  130  fit together they are co-axial. When the cover  30  is assembled to the base  20  as described above, the inner surface  40  of the cover contacts the rim  110  of the seal  90  and clamps it against the seat  52  of the support ring  50 . This clamping of the seal  90  against the support ring  50  secures the seal, the speaker  70  and the speaker grill  130  in place. The seal  90  supports the speaker grill  130  and the speaker  70  resiliently on the support ring  50 .  
         [0032]     With the housing  12  thus assembled to the seal  90 , a water resistant chamber  140  is formed in the housing  12 . The chamber  140  is defined by the base  20 ; the cover  30 ; the gasket  44  between the base and the cover; and the seal  90 . The circuit board  60  and the switch  66  are located inside the water resistant chamber  140 . The speaker  70  is located outside that water resistant chamber.  
         [0033]     The assembly  10  includes a microphone shown schematically at  142 . The microphone  142  is located on the outer surface  42  of the cover  30 . The microphone  142  is electrically connected with the circuit board by wires shown schematically at  144 .  
         [0034]     When a user of the lapel speaker-microphone assembly  10  wishes to activate the microphone  142 , the user pushes on the speaker grill  130 . The force on the speaker grill  130  is transmitted to the rim  82  of the speaker  70  and causes the speaker, which is resiliently supported by the seal  90 , to move toward the base  20 . The speaker grill  130  follows.  
         [0035]     As the speaker grill  130  and the speaker  70  move toward the base  20 , the speaker pushes against the lower and central portions  92  and  102  of the seal  90 . The side walls  108 ,  104 , and  100  of the upper, central and lower portions  106 ,  102  and  92 , respectively, of the seal  90  stretch as the speaker grill  130  and the speaker  70  push inward on the seal, thus deforming the seal.  
         [0036]     When the speaker grill  130  and the  70  speaker are pushed inward a sufficient amount, the back wall  98  of the seal  90  contacts the push-to-talk switch  66  located on the circuit board  60 . The switch  66  is activated, thus activating the microphone  142 .  
         [0037]     When the force on the speaker grill  130  is thereafter released, the resilience of the elastomeric seal  90  pulls the speaker  70  and the speaker grill back toward their starting position. As this movement occurs, the lower portion  92  of the seal  90  moves away from the circuit board  60 , and the switch  66  is deactivated.  
         [0038]     The speaker grill  130  is relatively large compared to the switch  66 , and also compared to other push to talk switches. For example, the speaker grill  130  could be one inch or more in diameter in a lapel unit  10 . Therefore, it is relatively easy for a user of the assembly  10  to push on the speaker grill  130  to activate the microphone  142 , even if the user is wearing gloves, for example. In addition, it is relatively easy for the user to locate the area on the exterior of the assembly  10  at which the user needs to apply force to activate the microphone  142 , because that location, the speaker grill  130 , is relatively large. The user need only swipe his or her hand across the front of the unit  10 , to activate the switch  66 .  
         [0039]     In one embodiment of the present invention, the lapel speaker-microphone assembly  10  includes an optional second push-to-talk switch  150  ( FIG. 4 ). The second push-to-talk switch  150  may be the normal one found in prior art lapel units. The second push-to-talk switch  150  is located on the outer surface  42  of the front wall  32  or side wall  34  of the cover  30 . The second push-to-talk switch  150  is electrically connected with the circuit board as shown schematically at  152 .  
         [0040]     Typically, the power for a lapel speaker-microphone assembly  10  of the type shown is provided, through the cable  26 , by the walkie-talkie  28  to which the lapel unit is connected. A lapel unit  10  in accordance with the present invention may optionally include a battery, rather than be powered over the cable. The battery would be located within the housing  12  and be electronically connected with the circuit board  60  by wires.  
         [0041]     A lapel speaker microphone assembly  10  in accordance with the present invention may include additional circuitry to provide the user with additional functions. For example, the assembly  10  may include circuitry to allow for interfacing to several different types of walkie-talkies. Additional circuitry could allow for interfacing with a mask-mounted microphone-speaker system. This circuitry would disable the microphone  142  in the lapel speaker-microphone assembly  10  whenever this mask mounted microphone-speaker system is attached.  
         [0042]     The lapel unit  10  could also include an emergency button. When the emergency button is pressed and released the microphone  142  of the assembly  10  would remain activated for an expended period, for example, up to fifteen seconds or more. Other variations and modifications of the invention, within the ordinary skill of the art, are intended also to be covered by the appended claims.