Patent Publication Number: US-2011051978-A1

Title: Earphone with detachable covers

Description:
BACKGROUND 
     1. Technical Field 
     The disclosure generally relates to audio devices, and particularly to an earphone having a front cover and a rear cover joined together conveniently. 
     2. Description of Related Art 
     With the continuing development of numerous technologies, earphones have been widely used in different fields, such as telephone communication, audio players, music reproduction, and so on. 
     A typical earphone includes a shell and a speaker in the shell. The shell includes a front cover and a rear cover. The rear cover is joined with the front cover via adhesive. However, the adhesive tends to decay under the influence of environmental factors such as ambient temperature, humidity and so on, which reduces the adhesive bonding between the front and rear covers. 
     What is needed, therefore, is an earphone which can overcome the described limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present earphone can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the disclosed earphone. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an assembled, isometric view of an earphone in accordance with one embodiment of the disclosure. 
         FIG. 2  is an exploded, isometric view of the earphone of  FIG. 1 . 
         FIG. 3  is an isometric view of a front cover of the earphone of  FIG. 2 . 
         FIG. 4  is an isometric view of a rear cover of the earphone of  FIG. 2 . 
         FIG. 5  is a cross sectional view of the earphone of  FIG. 1 , taken along line V-V thereof. 
         FIG. 6  is an enlarged, exploded view showing a joint portion between the front and rear covers of the earphone of  FIG. 5 . 
         FIG. 7  is an enlarged, exploded view showing another joint portion between the front and rear covers of the earphone of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , an earphone according to one embodiment of the disclosure is shown. The earphone includes a shell  10 , a speaker  20  received in the shell  10 , and a rubber cap  30  at a front end of the shell  10 . The shell  10  includes a front cover  11  and a rear cover  13  joined with the front cover  11 . A joint plane  15  is defined through a joint portion between the front and rear covers  11 ,  13 . 
     Referring to  FIGS. 2 ,  3 ,  5  and  7 , the front cover  11  is hollow and substantially hemispheric, and defines a front chamber  111  therein. A sound tube  112  extends horizontally and outwardly from a front end of the front cover  11  toward the rubber cap  30 . A longitudinal axis of the sound tube  112  is non-perpendicular to the joint plane  15  between the front and rear covers  11 ,  13 . The sound tube  112  is hollow and substantially cylindrical, and defines a sound channel  113  therein in communication with the front chamber  111 . A tuning mesh  114  is disposed at a front end of the sound channel  113 , for improving the sound quality factor and adjusting the sound sharpness of the speaker  20 . The sound channel  113  expands gradually from the rubber cap  30  toward the front cover  11  to form a trumpet shape at a rear end thereof, such that sound from the speaker  20  readily enters the sound channel  113 . The sound channel  113  defines an annular joint groove  115  in an outer circumference thereof. The sound tube  112  has an outer diameter gradually decreasing from the joint groove  115  toward the rubber cap  30 , thereby forming an inclined outer surface  116  at a front end of the sound tube  112 . The inclined outer surface  116  can assist in mounting the rubber cap  30  around the sound tube  112 . 
     The front cover  11  defines an opening  117  at a rear end thereof. The front cover  11  has a fixing flange  118  extending out from an inner side thereof adjacent to the opening  117 . The fixing flange  118  expands outwardly to form a spherical protrusion  119  at a free end thereof, whereby a mounting groove  120  is defined in an outer surface of the fixing flange  118  adjacent to and below the protrusion  119 . The fixing flange  118  defines two fixing cutouts  121  (shown in  FIG. 3 ) at left and right sides of a bottom portion thereof, respectively. The two fixing cutouts  121  divide the fixing flange  118  into two parts, i.e., an upper portion  122  above the two fixing cutouts  121  and a lower portion  123  below the two fixing cutouts  121 . The upper and lower portions  122 ,  123  of the fixing flange  118  are located in a circumference. Two blocks  124  (only one shown in  FIG. 3 ) extend respectively out from two opposite sides of the fixing flange  118  into the mounting groove  120 . The mounting groove  120  is closed up along a circumferential direction of the front cover  11  by the blocks  124 . The upper portion  122  of the fixing flange  118  defines a positioning cutout  125  in a middle thereof. 
     The front cover  11  forms a first step  126  and a second step  127  at an inner surface thereof, with both the first and second steps  126 ,  127  facing toward the front chamber  111 . The first and second steps  126 ,  127  are planar, and parallel to each other. The longitudinal axis of the sound tube  112  is perpendicular to the first step  126 . In other words, the first step  126  is nonparallel to the joint plane  15  between the front and rear covers  11 ,  13 . The first step  126  is located below the second step  127  (as viewed in  FIG. 3 ). The first step  126  is located adjacent to the sound tube  112 , and cuts the lower portion  123  of the fixing flange  118  into a triangle shape. The protrusion  119  of the lower portion  123  of the fixing flange  118  is also cut into a hemispheric shape by the first step  126 . The front cover  11  further has a semicircular positioning flange  128  protruding out at the inner surface thereof toward the front chamber  111 . The positioning flange  128  is located above the second step  127  (as viewed in  FIG. 3 ). A central plane  129  of the positioning flange  128  along a circumferential direction thereof is parallel to the first step  126 . In other words, the central plane  129  is nonparallel to the joint plane  15  between the front and rear covers  11 ,  13 . 
     Referring to  FIGS. 4-7 , the rear cover  13  is also hollow and substantially hemispheric, and defines a rear chamber  131  therein. The rear cover  13  defines an opening  137  at a front end thereof. The opening  137  faces the opening  117  of the front cover  11 . The rear cover  13  includes an outer cover  132  and an inner cover  133  in the outer cover  132 . The inner cover  133  is made of a rigid material, such as polyvinyl chloride (PVC) and so on, and is for supporting the speaker  20 . The outer cover  132  is made of a material which has a rigidity less than that of the inner cover  133  and a toughness greater than that of the inner cover  133 , such as rubber and so on, and is for improving a texture of an outer surface of the earphone and preventing a rupture of the earphone. 
     The outer cover  132  defines an annular and hemispheric fixing groove  139  in an inner surface thereof. The fixing groove  139  is located at a front end of the outer cover  132  adjacent to the opening  137 , whereby a mounting flange  140  corresponding to the fixing groove  139  protrudes out at the front end of the outer cover  132 . The mounting flange  140  defines two fixing cutouts  141  at left and right sides of a bottom thereof, respectively. The fixing cutouts  141  align with the fixing cutouts  121  of the front cover  11 , respectively, such that the speaker  20  is not blocked by the mounting flange  140  of the rear cover  13  and the fixing flange  118  of the front cover  11  during assembly. The two fixing cutouts  141  also divide the mounting flange  140  into two parts, i.e., an upper portion  142  above the two fixing cutouts  141  and a lower portion  143  below the two fixing cutouts  141 . The outer cover  132  has a hollow wire duct  134  extending downwardly at a rear end thereof. The wire duct  134  is provided for a wire (not shown) of the earphone to pass therethrough and electrically connect with the speaker  20 . 
     The inner cover  133  is adhered to the inner surface of the outer cover  132 . The rear chamber  131  is defined in the inner cover  133 . The inner cover  133  has a securing flange  148  extending forwardly out from an inner side thereof adjacent to the opening  137 . The securing flange  148  is semi-annular, and is located at a top of the inner cover  133 . The securing flange  148  defines a hemispheric fixing groove  149  in an outer surface thereof. The hemispheric fixing grooves  139 ,  149  of the outer and inner covers  132 ,  133  cooperatively form a spherical groove, for matching the protrusion  119  of the front cover  11 . The securing flange  148  defines a positioning cutout  145  aligning with the positioning cutout  125  of the front cover  11  in a middle thereof, whereby the front and rear covers  11 ,  13  can be positioned accurately during assembly. 
     The inner cover  133  has a semicircular positioning flange  158  protruding out at an inner surface thereof toward the rear chamber  131 . The semicircular positioning flanges  128 ,  158  of the front and inner covers  11 ,  133  cooperatively form a circular flange. The inner cover  133  defines a through hole  135  in a rear end thereof, in communication with the wire duct  134  of the outer cover  132 . 
     Referring to  FIGS. 2 and 5 , the rubber cap  30  is typically made of soft rubber material. The rubber cap  30  includes an inner tube  31 , and an outer cap  33  bending backwardly out from a front end of the inner tube  31 , with the inner tube  31  received in the outer cap  33 . The inner tube  31  is hollow and cylindrical, and defines a sound passage  313  therein. The sound passage  313  communicates with the sound channel  113  of the front cover  11 . The inner tube  31  has an annular joint flange  315  protruding out from a rear end thereof into the sound passage  313 . The joint flange  315  is engaged in the joint groove  115  of the sound tube  112  of the front cover  11 . A height of the joint flange  315  is slightly less than a depth of the joint groove  115  along a radial direction of the sound passage  313 . The inner tube  31  defines an inclined groove  316  in front of the joint flange  315 . A depth of the inclined groove  316  along the radial direction of the sound passage  313  gradually decreases in a forward direction, thereby complementarily matching the inclined outer surface  116  of the sound tube  112 . 
     The speaker  20  includes a frame  21 . The frame  21  has a first abutting portion  216  and a second abutting portion  217  at a front end thereof, and a positioning portion  218  at a rear end thereof. The first abutting portion  216  is substantially flat. Each of the second abutting portion  217  and the positioning portion  218  is annular and planar. 
     During assembly of the earphone, the speaker  20  is pushed into the front chamber  111  of the front cover  11  along the first step  126  from the fixing cutouts  121  of the front cover  11 . The first and second abutting portions  216 ,  217  of the speaker  20  abut against the first and second steps  126 ,  127  of the front cover  11 , respectively. The positioning portion  218  of the speaker  20  abuts against the positioning flange  128  of the front cover  11 . The fixing grooves  139 ,  149  of the rear cover  13  are aligned with the fixing flange  118  of the front cover  11 . The positioning cutout  145  of the securing flange  148  of the rear cover  13  is aligned with the positioning cutout  125  of the upper portion  122  of the fixing flange of the front cover  11 . The rear cover  13  is pressed toward the front cover  11  until the fixing flange  118  of the front cover  11  is engaged in the fixing grooves  139 ,  149  of the rear cover  13 , with the upper and lower portions  142 ,  143  of the mounting flange  140  of the rear cover  13  engaged in the mounting groove  120  of the fixing flange  118  of the front cover  11 . At this time, two ends of the upper portion  142  of the mounting flange  140  of the rear cover  13  adjacent to the fixing cutouts  141  abut against the blocks  124  of the upper portion  122  of the fixing flange  118  of the front cover  11 , respectively. The positioning flange  158  of the rear cover  13  and the positioning flange  128  of the front cover  11  cooperatively form an annular flange. The positioning portion  218  of the speaker  20  abuts against the positioning flange  158  of the rear cover  13  and the positioning flange  128  of the front cover  11 . 
     The rear end of the sound passage  313  of the rubber cap  30  adjacent to the joint flange  315  is aligned with the sound tube  112  of the front cover  11 . The rubber cap  30  is pressed toward the front cover  11  until the joint flange  315  of the rubber cap  30  slides into the joint groove  115  of the sound tube  112  along the inclined outer surface  116  of the front of the sound tube  112 . At this time, the inclined groove  316  of the inner tube  31  of the rubber cap  30  matches the inclined outer surface  116 . 
     In the earphone, the protrusion  119  of the front cover  11  is engaged in the fixing grooves  139 ,  149  of the rear cover  13 . Thereby, the front and rear covers  11 ,  13  can be joined together steadily, and the front and rear covers  11 ,  13  can be attached together and detached from each other conveniently. There is no need to provide adhesive to join the front and rear covers  11 ,  13  together, thereby mitigating any risk of an insecure joint between the front and rear covers  11 ,  13  due to decay of the adhesive. 
     In addition, the mounting flange  140  of the rear cover  13  is engaged in the mounting groove  140  of the front cover  11 , which further joins the front and rear covers  11 ,  13  together. Furthermore, the two ends of the upper portion  142  of the mounting flange  140  of the rear cover  13  adjacent to the fixing cutouts  141  abut against the blocks  124  of the upper portion  122  of the front cover  11 , respectively. Accordingly, the rear cover  13  is prevented from rotating along a circumferential direction of the shell  10  after assembly, so that the rear cover  13  is firmly attached to the front cover  11 . 
     Moreover, the first and second abutting portions  216 ,  217  of the speaker  20  abut respectively against the first and second steps  126 ,  127  of the front cover  11 , and the positioning portion  218  of the speaker  20  abuts against the positioning flanges  128 ,  158  of the front and rear covers  11 ,  13 . In other words, the speaker  20  is sandwiched between the steps  126 ,  127  and the positioning flanges  128 ,  158 , which helps to secure the speaker  20  in the earphone. The positioning flanges  128 ,  158  are respectively formed on the front and rear covers  11 ,  13 , and the central plane  129  of the positioning flange  128  is nonparallel to the joint plane  15  between the first and second covers  11 ,  13 . Accordingly, the speaker  20  can slide into the front cover  11  from an outer side of the front cover  11 . That is, it is convenient to assemble the speaker  20  into the shell  10 . 
     Alternatively, the protrusion  119  and the mounting groove  120  of the front cover  11  can be formed on the rear cover  13 , and simultaneously, the fixing grooves  139 ,  149  and the mounting flange  140  of the rear cover  13  are formed on the front cover  11 . 
     It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.