Patent Publication Number: US-9414154-B2

Title: Water-repellent earphone

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an earphone and more particularly, to a water-repellent earphone which can drain moisture quickly to prevent the built-in speaker from damage and enhance the acoustic performance. 
     2. Description of the Related Art 
     A regular earphone includes a venthole that is usually located at the rear side of the housing. When a speaker of the earphone emits sound, a venthole and a waterproof ventilative member covering the venthole jointly regulate the inflow and outflow of a gas inside a rear chamber of the earphone, thus reducing the pressure of the gas and affecting the acoustic performance of the earphone particularly for frequency response within low-frequency range. 
     A conventional earphone, e.g. U.S. Pat. No. 4,646,872, referring to  FIG. 2 , includes a housing  2  having a receiving space for receiving a speaker unit  1 . A duct  7  is formed at a rear end of the housing  2  for communication with an opening of a housing cap  9  for making a gas inside a rear cavity  8  communicable with the external environment. To prevent moisture from entering the rear cavity  8 , this patent disclosed a waterproof ventilative mesh  10  for covering the opening the rear cavity  9 . In addition, a series of tests are applied to the frequency response of the earphone after the earphone is soaked in or doused with water. Referring to  FIGS. 6 and 7  of this patent, when the earphone is wiped dry after it is soaked or doused with water, the frequency response of the earphone within the low-frequency range lowers to a certain degree and as the time passes by, the gain of the low-frequency range gradually is restored as what it is before soaked in or doused with water. 
     Although it is known from the aforesaid patent that the moisture indeed affects the earphone, that patent is devoid of an applicable drainage protocol, so the earphone fails to expel the moisture quickly, after it is soaked in or doused with water, and to enhance the frequency response within the low-frequency range up to what it is before the earphone soaked in or doused with water. For this reason, this conventional earphone needs further improvement. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a water-repellent earphone which can quickly expel moisture to prevent the moisture from entry and damage to a built-in speaker thereof and to boost the frequency response within the low-frequency range. 
     The foregoing objective of the present invention is attained by the water-repellent earphone formed of a main body and a water-repellent breathable member. The main body includes a receiving space formed therein and a speaker mounted inside the receiving space. The speaker partitions the receiving space to make a rear chamber. The main body includes a drainage tunnel formed therein for communication with a first opening and a second opening, both of which are located on an external surface of the main body. The main body further includes a venthole communicating with the drainage tunnel and the rear chamber. The water-repellent breathable member is formed and located at the venthole. 
     In light of the structure mentioned above, the drainage tunnel can help the earphone quickly expel the moisture to prevent the moisture from entering the main body of the earphone and from damage to the speaker and to quickly restore the frequency response within the low-frequency range. 
     Preferably, the first opening, the venthole, and the rear chamber communicate with one another linearly. 
     Preferably, the drainage tunnel includes a curved portion and a straight portion, both of which communicate with each other and communicate with the first opening and the second opening, respectively. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially exploded view of a preferred embodiment of the present invention. 
         FIG. 2  is a partially top view of the preferred embodiment of the present invention. 
         FIG. 3  is a sectional view taken along a line  3 - 3  indicated in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Structural features and desired effects of the present invention will become more fully understood by reference to a preferred embodiment given hereunder. However, it is to be understood that the embodiment is given by way of illustration only, thus is not limitative of the claim scope of the present invention. 
     Referring to  FIGS. 1-3 , a water-repellent earphone  1  constructed according a preferred embodiment is formed of a speaker  10 , a main body  20 , and a water-repellent breathable member  30 . The speaker  10  serves as a sound maker. It is worth mentioning that the sounding orientation is forward-based. The detailed descriptions and operations of these elements as well as their interrelations are recited in the respective paragraphs as follows. 
     The main body  20  is formed of a front cover  21  and a housing  22  connected with the front cover  21 . The front cover  21  is provided with a plurality of sound holes  211  for the sound to pass through. Referring to  FIG. 3  again, the front cover  21  and the housing  22  jointly include a receiving space  23  formed therein for fixedly accommodating the speaker  10 . The speaker  10  is fixed to the front cover  21  and partitions the receiving space  23  to make a rear chamber  231 . The housing  22  is provided with a through hole  28  formed at a bottom side thereof for an element (not shown) like a bass tube or an audio cable to pass through. 
     The housing  22  includes a drainage tunnel  26  formed at a rear side thereof, a first opening  24  formed at a top side thereof, a second opening  25  formed at a bottom side thereof, and a venthole  27  formed therein. The drainage tunnel  26  communicates with the first and second openings  24  and  25 . In addition, the drainage tunnel  26  communicates with the rear chamber  231  via the venthole  27  to make a gas inside the rear chamber  231  exhaust through the first opening  24  and/or the second opening  25  via the venthole  27 . The drainage tunnel  26  is formed of a curved portion  261  and a straight portion  262  communicating with the curved portion  261 . The curved portion  261  and the straight portion  262  are recessed inward from an external rear surface of the housing  22 . The curved portion  261  is L-shaped and includes one end communicating with the first opening  24  and a corner portion communicating with the venthole  27  to make the first opening  24  and the venthole  27  communicable with each other linearly. The straight portion  262  communicates with the second opening  25  as shown in  FIG. 1 . The housing  22  further includes a rear cover  40  at the rear side thereof for covering the external rear surface thereof. It is worth mentioning that the rear cover  40  can be integrally formed on the housing  22  instead, so it is not an essential element of the present invention; in addition, the second opening  25  can be formed on the rear cover  40  instead as the drainage tunnel  26  still functions normally. 
     The water-repellent breathable member  30  is formed of a plurality of pores, each of which is smaller than the venthole  27  in diameter, or formed of at least one metallic mesh made of stainless steel or at least one ventilative film made of polyurethane (PU) or polymeric material. The water-repellent breathable member  30  is formed in the venthole  27  for making the gas inside the rear chamber  231  be dissipated outward and meanwhile for preventing external moisture from entering the rear chamber  231 , so the earphone  1  can have preferable acoustic performance within low-frequency range. 
     In operation, when the moisture does not enter the drainage tunnel  26  through the first opening  24 , the gas inside the rear chamber  231  can flow out of the earphone  1  from the venthole  27  through the drainage tunnel  26  to properly decrease the pressure of the gas inside the rear chamber  231  and enhance the low-frequency acoustic performance when the speaker  10  makes sound. Since the first opening  24  and the venthole  27  communicate with each other linearly, the gas inside the rear chamber  231  can be easily dissipated. 
     When it is raining or a user is doing exercise, the rain or perspiration may enter the drainage tunnel  26  through the first opening  24 . In the meantime, the water-repellent breathable member  30  can prevent the rain or perspiration from entering the rear chamber  231  and the rain or perspiration can be expelled out of the earphone  1  quickly through the drainage tunnel  26 . Thus, the moisture can be prevented from entering the main body  20  of the earphone  1  and from damage to the speaker  10  and the frequency response of the earphone  1  within the low-frequency range can be restored to the gain as it is before the moisture enters the drainage tunnel  26 , thus enhancing the acoustic performance of the earphone  1 . 
     It is to be noted that the technical personnel in the art can make a third opening or more openings on the housing  22  to boost the drainage. In addition, the first and second openings  24  and  25  are not necessarily located at the top and bottom sides of the rear end of the housing  22  and can be located at other positions of the housing instead as long as the path between the venthole  27  and the first opening  24  or the second opening  25  makes the gas inside the rear chamber  231  communicable with the outside successfully.