Abstract:
A portable radiotelephone apparatus having a microphone and an earpiece electrically connected individually to respective wires of a two-wire electrical line, and a retraction mechanism with a one-way lock device for the line.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to a portable radiotelephone apparatus, particularly a cellular phone, having extensible and retractable electrical wiring for the user&#39;s earpiece-speaker and a microphone that can be positioned on the user for hands-free use of the phone.  
           [0003]    2. Prior Art  
           [0004]    U.S. Pat. No. 6,082,651 to Thornton discloses a cellular phone with an extensible and retractable cord connecting it to a handset which has the usual speaker enabling the user to hear the voice of the person to whom he or she is speaking and a microphone into which the user speaks. A spring-operated cord retraction mechanism located inside the phone housing has a one-way lock enabling the cord to be pulled out and then automatically locking it in its pulled-out position for use of the handset in a phone call. A manually-operated release for the lock device enables the cord retraction mechanism to retract the cord into the phone housing after the user is finished with the phone call.  
           [0005]    The following U.S. patents show cellular phone headsets or other unitary devices with a microphone and an earpiece-speaker that communicate with the user&#39;s cellular phone in various ways:  
           [0006]    Hahn et al U.S. Pat. No. 6,078,82—radio communication;  
           [0007]    Vangarde U.S. Pat. No. 5,504,812 and Hwang U.S. Pat. No. 6,122,369—electrical wiring;  
           [0008]    Guenther U.S. Pat. No. 5,613,222—either electrical wiring or sound tubing from the microphone to the cell phone, and sound tubing from the phone to the user&#39;s earpiece-speaker; and  
           [0009]    Chan U.S. Pat. No. 5,528,689—sound tubes between the cellular phone and both the microphone and the earpiece-speaker.  
         SUMMARY OF THE INVENTION  
         [0010]    This invention relates to a portable radio telephone apparatus having an extensible and retractable electrical line with a wire to an earpiece containing a speaker and a wire to a small microphone that is physically discrete from the earpiece, the only connection between them being provided by wiring. To initiate or answer a phone call, the user pulls the line away from its housing so that he or she can position the microphone and the earpiece for convenient and effective use. When the user is finished with the call, he or she initiates the automatic retraction of the line into its housing by a spring-operated line retraction mechanism simply by exerting a brief outward pull on the extended line and then releasing it for retraction into the housing to position the earpiece and the microphone next to the housing where they are readily accessible for future use.  
           [0011]    One advantage of this invention is to ally the fears of many persons who fear radiation from a cellular phone held next to the head or from a hand set for a cell phone that also is held next to the head. Whether or not such fear is justified, it does inhibit some people from using cell phones and creates anxiety in others who do. With the present invention, the cell phone housing and its conspicuous antenna can be located away from the user&#39;s head while the user makes use of the small unobtrusive microphone and the earpiece to carry on a phone conversation. The absence of a handset not only is reassuring to some users, it facilitates hands-free use of the phone for all users, particularly those who use a phone while driving a car or truck.  
           [0012]    Further objects and advantages of the invention will be apparent from the following detailed description of three presently preferred embodiments thereof, illustrated in the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a front elevation of a cellular phone of otherwise conventional design that is equipped with a line retraction arrangement in accordance with a first embodiment of the present invention;  
         [0014]    [0014]FIG. 2 is an end view of this phone taken from the right in FIG. 1;  
         [0015]    [0015]FIG. 3 is a front view of a person using the cellular phone of FIG. 1 with the earpiece and the microphone pulled out from the phone and worn by the user;  
         [0016]    [0016]FIG. 4 is a longitudinal vertical section taken along the line  4 - 4  in FIG. 1 through the upper part of the phone housing, with part of the lock device for the line retraction mechanism broken away to expose other parts, and showing the two-wire electrical line fully retracted;  
         [0017]    [0017]FIG. 5 is a fragmentary vertical section taken along the line  5 - 5  in FIG. 4 and showing the microphone and the earpiece seated in the top of the phone housing when the line is fully retracted;  
         [0018]    [0018]FIG. 6 is a fragmentary top plan view of these parts, taken along the line  6 - 6  in FIG. 4;  
         [0019]    [0019]FIG. 7 is a longitudinal horizontal section taken along the line  7 - 7  in FIG. 4, looking down on the line retraction mechanism and its lock device in this embodiment of the invention;  
         [0020]    [0020]FIG. 8 is a longitudinal horizontal section taken along the line  8 - 8  in FIG. 4 looking up at the line retraction mechanism and its lock device;  
         [0021]    [0021]FIG. 9 is a vertical cross-section, with one part broken away, taken along the line  9 - 9  in Fig. And showing the line retraction mechanism and its lock device in end elevation;  
         [0022]    [0022]FIG. 10 is a vertical cross-section taken along the line  10 - 10  in FIG. 7 at the centerline of the takeup reel of the line retraction mechanism;  
         [0023]    [0023]FIG. 11 is a fragmentary longitudinal vertical section taken along the line  11 - 11  in FIG. 10;  
         [0024]    [0024]FIG. 12 is a view similar to FIG. 4 and showing the line retraction mechanism and its lock device when the two-wire line is being pulled out of the cell phone housing;  
         [0025]    [0025]FIG. 13 is a view similar to FIG. 12 and showing the position of these parts when the lock device is released to permit the line retraction mechanism to retract the extended line;  
         [0026]    [0026]FIG. 14 is an exploded perspective view of the hub sub-assembly for rotatably supporting the takeup reel of the line retraction mechanism and the ratchet wheel of the lock device in this embodiment of the invention;  
         [0027]    [0027]FIG. 15 is a fragmentary elevation of the earpiece, the microphone and an attachment clip for the microphone in this embodiment of the invention;  
         [0028]    [0028]FIG. 16 is a fragmentary elevation showing a second arrangement for positioning the microphone and the earpiece next to the phone when the line is retracted by a mechanism as shown in the first embodiment of this invention;  
         [0029]    [0029]FIG. 17 is a top plan view of the FIG. 16 sub-assembly;  
         [0030]    [0030]FIG. 18 is a side elevation of the microphone in a third embodiment of this invention, with the microphone casing broken away at one end;  
         [0031]    [0031]FIG. 19 is a longitudinal vertical section taken along the line  19 - 19  in FIG. 18, showing the lock device for the earpiece wire retraction mechanism inside the microphone casing;  
         [0032]    [0032]FIG. 20 is a view of the FIG. 18 device, partly in vertical cross-section and partly in side elevation;  
         [0033]    [0033]FIG. 21 is a longitudinal vertical section taken along the line  21 - 21  in FIG. 20, showing in cross-section the takeup reel of the wire retraction mechanism inside the microphone casing;  
         [0034]    [0034]FIG. 22 is a top plan view showing the microphone of FIGS.  18 - 21  mounted on top of the housing of a cellular phone;  
         [0035]    [0035]FIG. 23 is a side elevation showing the manner in which the microphone and the earpiece of this embodiment of the invention are supported on the antenna of the cell phone;  
         [0036]    [0036]FIG. 24 is a rear elevation of the microphone casing provided with a spring clip for mounting purposes; and  
         [0037]    [0037]FIG. 25 is a front view of a person using the cellular phone with the microphone of FIGS.  18 - 24  pulled out from the phone and worn by the user and the earpiece pulled away from the microphone and worn by the user. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0038]    Before explaining the present invention in detail it is to be understood that the invention is not limited in its application to the particular arrangements shown and described herein since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.  
         [0039]    Referring to FIGS.  1 - 3 , in accordance with a first embodiment of the present invention a cellular phone  30  of conventional design and operating characteristics is provided with a spring-operated wire retraction mechanism having a takeup reel  31  (FIGS. 4, 7,  8 ,  9  and  10 ) holding a two-wire electrical line  32  (FIG. 4). Line  32  has a first insulated electrical wire  33  leading to an earpiece  34  containing a conventional speaker and a second electrical wire  35  leading to a conventional microphone  36 . As shown in FIG. 3, the earpiece  34  may be inserted in a person&#39;s ear so that he or she may hear from the earpiece speaker the voice of the person he or she is conversing with over the cell phone, and the microphone  36  may be removably attached to the user&#39;s clothing at the neckline so as to pass to wire  35  the electrical signals representing the words spoken into the microphone by the user.  
         [0040]    The cell phone  30  has a housing with a generally flat front wall  37  (FIG. 2), a generally flat back wall  38  extending substantially parallel to the front wall, and opposite side walls  39  and  40  and top and bottom walls  41  and  42  (FIG. 1) connecting the back and front walls. A housing chamber  43  above an internal wall W of the housing (FIG. 4) holds the line retraction mechanism and its lock device. The line retraction mechanism has a takeup reel  31  located closely in front of the housing back wall  38 . The lock device has a ratchet wheel  44  rigidly attached to the takeup reel for rotation of the two in unison and is located within the housing closely behind the front wall  37 . As shown in FIG. 10, a pair of cylindrical stubs  31   a  and  31   b  integral with the inner face of takeup reel  31  engage the inner face of ratchet wheel  44  to space them apart and provide room between them for a spirally wound spring  45  (FIGS. 4 and 10) similar to the mainspring of a mechanical watch or clock. Bolts  46  attach the ratchet wheel to the takeup reel.  
         [0041]    Takeup reel  31  and ratchet wheel are both affixed to a fixedly positioned cylindrical hub  47  (FIG. 10) which has a reduced end segment  48  with flat opposite side faces  48   a  and  48   b  (FIG. 11) received in a complementary recess  49  formed in a small cylindrical support plate  50  (FIG. 4). Plate  50  is fixedly seated in a complementary recess  51  on the inside of the housing front wall  37 . Hub  47  is part of a sub-assembly (FIG. 14) located centrally of the takeup reel and the ratchet wheel. At its inner end the hub  47  presents a cylindrical recess  52  that rotatably receives a short cylindrical shaft  53  having a diametrically opposed pair of longitudinal extensions  53   a  and  53   b  that are rotatably received in a cylindrical bushing  54  which, as shown in FIG. 10, is fixedly seated in a complementary recess  55  formed in the outer face of takeup reel  31 .  
         [0042]    As shown in FIG. 4, the spiral spring  45  (which is part of the line retraction mechanism) has a transverse inner end segment  45   a  secured to the fixedly positioned hub  47  and an outer end loop  45   b  attached to the rotatable takeup reel  31  and ratchet wheel  44  by a cross pin  56 . Spring  45  urges the takeup reel and the ratchet wheel counterclockwise in FIG. 4, thereby acting to wind up the two-wire phone line  32  on the takeup reel and retract the line into the cell phone housing.  
         [0043]    As shown in FIGS. 10 and 13, line  32  passes through a small radial passage  57  in the takeup reel and through the space between the extensions  53   a  and  53   b  of the rotatable shaft  53  and out through the support ring  54  and a central opening  58  (FIG. 10) in the housing back wall  38  to the circuitry (not shown) in the lower part of the cell phone below chamber  43  so that outgoing voice messages from the user&#39;s microphone  36  are conducted to the cell phone circuitry and incoming voice messages are conducted from the cell phone circuitry to the user&#39;s earpiece  34 .  
         [0044]    If desired, the cell phone circuitry may be in a different housing from the one that holds takeup reel  31  and ratchet wheel  44 . In that case, the battery pack for the cell phone may be in either the housing for the takeup reel and ratchet wheel or the housing for the cell phone circuitry.  
         [0045]    As shown in FIG. 4, ratchet wheel  44  is formed with a plurality of teeth  59  in succession along its periphery, each having a relatively long, flat, slanted face  60  and a short, flat, radial face  61  extending between the outer end of the slanted face  60  of one tooth and the inner end of the slanted face  60  of the next tooth. The lock device also includes a pawl  62  pivotally mounted at  63  and presenting an upwardly projecting tooth  64  for engaging the toothed periphery of ratchet wheel  44 . A reversely bent spring  65  biases the pawl against the ratchet wheel to normally position the pawl tooth  64  in locking engagement with the radial face  61  of the adjacent tooth  59  on the ratchet wheel, thereby locking the ratchet wheel against counterclockwise rotation in FIG. 4 under the urging of spring  45 , which is the direction for winding up the two-wire line  32  on the takeup reel.  
         [0046]    The lock device also includes a line hold-down finger  66  pivoted at  67  to the free end of pawl  62  (i.e., the end away from the latter&#39;s pivot  63 ). Finger  66  passes snugly but freely between the opposite sides of a bifurcated guide  68  (FIGS. 7 and 8) fixedly mounted on the inside of the cell phone housing and it presents an inwardly projecting tip segment  69  with a rounded surface that engages the line  32  to hold it snugly in place on takeup reel  31 . As shown in FIG. 9, finger  66  is formed with a bend at  70  a short distance below the guide  68 , and it projects down from this bend at an angle away from the takeup reel  31  and toward the ratchet wheel  44  to another bend at  71 , and then downward parallel to the takeup reel to its pivotal connection at  67  to the pawl  62 .  
         [0047]    As shown in FIG. 4, the two-wire line  32  passes slidably up through a vertically elongated, tapered opening  72  in a line guide segment  73  of the cell phone housing that is molded integral with the housing top wall  41 . When the line is fully retracted, the outer ends of its two wires  33  and  35  are received in a recess  74  formed in the housing just above the upper end of the opening  72  in its line guide segment  73 , and the earpiece  34  and the microphone  36  are seated in an open-topped enlargement  75  of recess  74  at the latter&#39;s upper end.  
         [0048]    An on/off switch  76  for the cell phone is mounted just below recess  75  and presents an upwardly-projecting, spring-biased plunger  77  that turns this switch on and off, the switch contacts being open when the plunger is depressed and closed when the plunger is in its uppermost position (to which it is spring-biased). The casing of microphone  36  presents a projection  36   a  on one side that engages the top of the switch plunger  77  and holds it down (against the upward force of its bias spring) in the switch-off position when the microphone is seated in the housing recess  75 . As shown in FIG. 6, on the opposite side from its switch-operating projection  36   a  the microphone casing presents a pair of oppositely curved, flexible and resilient fingers  36   b  and  36   c  that grip the earpiece  35  between them in a manually separable manner.  
         [0049]    Referring to FIG. 12, when the user wants to use the cell phone he or she pulls the earpiece  34  and the microphone  36  together up from recess  75  in the housing top wall. This begins to unwind the line  32  from the takeup reel  31 , causing the ratchet wheel  44  to turn clockwise in this Figure of the drawing, riding easily over the pawl  62  because of the inclination of the slanted faces  60  of its successive teeth. As soon as the user relaxes the outward pull on line  32 , the pawl  62  returns to the position shown in FIG. 4, locking the ratchet wheel  44  and the takeup reel  31  against turning in the line-retracting direction in which spring  45  urges them. The user separates the microphone  36  from the earpiece  34  and attaches the microphone to an alligator clip  78  (FIG. 15) that has a cylindrical post  79  on top for gripping engagement by the curved fingers  36   b  and  36   c  on the microphone casing. The microphone can then be clipped to the user&#39;s shirt or other wearing apparel at the neckline, as shown in FIG. 3, and the earpiece  34  inserted in one ear of the user. The cell phone casing has a spring clip  80  on the back (FIG. 2) enabling it to be attached to the user&#39;s belt or some other convenient location on the user&#39;s apparel. As soon as the projection  36   a  on the microphone disengages from the switch plunger  77 , the switch  76  automatically turns the cell phone on so that it is ready for use as soon as the user has the earpiece  34  and the microphone  36  in place as shown in FIG. 3.  
         [0050]    After the user has finished using the phone the two-wire line  32  can be retracted into the phone housing by the takeup reel  31  by first exerting a brief outward pull or tug on the line to fully extend it and cause ratchet wheel  44  to push pawl  62  out of engagement with its toothed periphery (FIG. 13). When the user now releases the outward pull on the line, the coil spring  45  turns the takeup reel  31  and the ratchet wheel  44  counterclockwise in this Figure of the drawings, retracting the line into the phone housing and winding it on the takeup reel.  
         [0051]    [0051]FIGS. 16 and 17 show a second embodiment of the invention in which the top recess  75  in the cell phone housing and the on/off switch  76  operated by the microphone casing are omitted. In other respects the cell phone, the line retraction mechanism and its lock device are the same as in the just-described first embodiment of the invention. In this second embodiment of the invention the microphone and the earpiece are mounted on the usual antenna structure A projecting up from the cell phone housing. The microphone casing  90  has an apertured projection  91  on the back that is formed with an opening  92  for snugly but slidably receiving the upwardly projecting antenna structure A to mount the microphone on it. Behind the projection  91  the microphone casing presents a pair of oppositely curved, flexible and resilient fingers  93  and  94  that grasp the earpiece  95  between them in the same manner as in the first embodiment of the invention, thereby attaching the earpiece to the microphone so that both are positioned on the antenna structure A when the cell phone is not in use. The earpiece can be manually separated from the microphone after they are detached from the antenna structure A when the phone is to be used.  
         [0052]    In the third embodiment of the invention (FIGS.  18 - 25 ) the cell phone  130  may be substantially identical to the one in the first embodiment, with the same kind of line retraction mechanism and a lock device for it. The two-wire electrical line  132  (FIG. 25) extends from the phone to the casing of a microphone  136  which contains a retraction mechanism and its lock device for an insulated wire  133  that goes from the microphone to the earpiece  134 . That is, the line from the cell phone  130  to the microphone casing contains two insulated electrical wires, one for the microphone and another for the earpiece.  
         [0053]    Inside the microphone casing is a line retraction mechanism and its lock device for retracting the wire  133  that goes from the microphone casing to the earpiece  134 . This retraction mechanism and the lock device associated with it are functionally but not structurally identical to those in the cell phone casing of FIGS.  1 - 15 . Elements of the line retraction mechanism and its lock device in microphone casing are given the same reference numerals plus  100  as the corresponding functional elements of the embodiment of FIGS.  1 - 15 , so the detailed description of these corresponding elements need not be repeated.  
         [0054]    The microphone casing has a convex front piece  101  (FIG. 20) formed with a plurality of openings  102  for passing sound from the user&#39;s voice to the usual electroacoustic transducer inside. The microphone casing also has a back piece  103  with an annular peripheral flange  104  threadedly attached to a mating part of front piece  101 .  
         [0055]    As shown in FIG. 19, the ratchet wheel  144  of the lock device for the line retraction mechanism inside the microphone casing is ring-shaped and presents ratchet teeth  159  in succession along its inside circumference. The pawl  162  of this lock device is positioned inside the ring formed by the ratchet wheel and it presents an outwardly projecting locking tooth  164  for engagement with the toothed inside periphery of the ratchet wheel.  
         [0056]    As shown in FIG. 20, the takeup reel  131  of the line retraction mechanism inside the microphone casing has a peripheral groove  200  for holding successive turns of the insulated wire  133  leading from the microphone casing to the earpiece  134 . Reel  131  has a radial passage  157  (FIG. 21) leading from its peripheral groove  200  to a central recess  201  that is open at the inside of the microphone casing to pass this wire to an opening provided with an annular fitting  202  in the front piece  201  of this casing. As shown in FIG. 20, the microphone wire  135  of the two-wire line also comes into the microphone casing through fitting  202 . Outside the microphone casing, the two insulated wires  133  and  135  are joined physically together to form the single two-wire line  132  for ease of handling.  
         [0057]    From the peripheral groove  200  in the takeup reel  131  the earpiece wire  133  passes through a tapered opening  203  (FIG. 19) in the back piece  103  of the microphone casing. When the earpiece wire is fully retracted, as shown in FIG. 19, the earpiece  134  seats in a partly complementary recess  204  formed in the outside of back piece  103  at the outer end of its opening  203 .  
         [0058]    The antenna A on the top of the cell phone  130  carries a bifurcated fitting  205  (FIGS. 22, 23 and  25 ) that presents resilient, oppositely curved, arcuate fingers  206  and  207  that grip the antenna between them and a segment  208  (FIG. 22) that projects behind these fingers and presents an opening  209  from top to bottom in FIG. 23.  
         [0059]    A spring clip  210  is rigidly attached in cantilever fashion to the back  103  of the microphone casing for snug reception in the opening  209  in the antenna fitting to mount the microphone on the antenna when the phone is not in use. As shown in FIG. 24, spring clip  210  presents a flat attachment segment  211  formed with a circular opening for snugly receiving a circular boss  212  (FIGS. 18 and 20) on the back of the microphone casing so that this attachment segment of the spring clip fits flat against the back wall  103  of the microphone casing. From this attachment segment the clip extends up across the back of the microphone casing to a curved top segment  213  (FIG. 23) and then down through the opening  209  in the antenna fitting  205  to an oppositely curved free end segment  214  at the bottom.  
         [0060]    When the cell phone is not in use, the spring clip  210  mounts the microphone  100  and the retracted earpiece  134  on the cell phone antenna A as shown in FIGS. 22 and 23. When the cell phone is to be used, the spring clip  210  on the microphone is removed from the antenna fitting  205 , and it may be attached to the user&#39;s clothing at the neckline (FIG. 25).  
         [0061]    From the foregoing detailed description taken in conjunction with the accompanying drawings, it will be apparent that each of the disclosed embodiments of this invention provides for the effective positioning of the microphone and the earpiece on the cell phone when the phone is not in use, and for the convenient positioning of the microphone and the earpiece on the user in a manner to allay any fear the user may have about radiation from the cell phone when it is in use.