Abstract:
A retractable cable reel assembly that has a spring loaded cable reel which attaches to a midpoint of a cable and when rotated by the spring, winds both ends of the cable up on the cable reel. A releasable detent arrangement is used to retain a desired amount of cable extending from the assembly.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    Many electronic devices include cable connected accessories such as speakers, computer input mice, headsets and the like which are used at varying distances from the base electronic or electrical device. In the case of telephones, a common expedient is to provide a curly cord between the telephone base and the handset to allow the handset to be moved a variable distance from the base and yet not have excess lengths of cord present. However, curly cords have a disadvantage because users commonly twist the handset one turn every time the telephone is answered. This results in a double twisted curly cord, which may not extend properly. In the case of vacuum cleaners, it is common to provide a cable reel which plays cord out for connection to a wall socket. Usually, the cable reel is spring loaded to wind the cord up and includes some sort of catch mechanism to maintain the cord extended from the reel case in predetermined lengths. Since one end of the cord is being coiled up, some sort of commutator is normally required between cord reel and vacuum cleaner to assure electrical contact is maintained. In other than electrical power applications, such commutators are noisy and require almost constant maintenance  
           [0002]    Optical cables are now being run in internal structures to provide high speed communications. Since interior runs may be short or long, a great deal of effort has been expended in developing connectors for such optical cables that can be installed in the field. Unfortunately, no matter how good the connector, alignment between the connector and the optical fiber is critical and connectors installed in a factory usually have less optical loss than those installed in the field. Therefore, optical cables are made at the factory in standard lengths greater than the expected connection distance. Then the extra cable length is taken up by wrapping the cable back and forth an overhead cable tray, coiling it in walls, or just leaving it in a snarled mess behind computer furniture.  
           [0003]    In all the few applications mentioned above and many others, it is desirable to provide means that neatly provide a cable the right length without requiring unsightly coils, cable trays or, in the case of optical cables, in the field connector installation.  
         SUMMARY OF THE INVENTION  
         [0004]    In the present invention, a cable reel is provided that retains a cable somewhere near its midpoint and winds up both ends equally without twisting the cable. The reel is spring loaded to wind its connected cable up from the center outward with the reel continuing to float somewhere in the midpoint of the cable.  
           [0005]    In use, one end of the cable is connected to a device and the other is pulled so that cable plays out from the reel in opposite directions with the reel remaining near a midpoint of the cable and moving about half the distance the free end moves. The reel and its case are constructed of light materials so the cable reel assembly does not overly stress the cable. A catch mechanism is provided so that once cable is pulled from the reel a desired amount, it tends to remain with that amount extending from the assembly until an optional catch within the assembly is manually released to allow the spring to wind up the cable.  
           [0006]    Some of the applications for the subject invention include: connecting a handset to a conventional phone; connecting a headset including earpiece and microphone to a conventional phone, a cell phone, and a belt mounted wireless phone; and connections between audio and video equipment or anyplace where a retractable “cable stretcher” is needed. A particularly interesting application is when optical cables are factory made to standard lengths with any extra length taken up by the present invention somewhere along the cable so that a range of distances can be neatly connected with optical cable by having the present invention take up the unneeded length.  
           [0007]    It is therefore an object of the present invention to efficiently provide means to vary the length of cable from a position along its middle which can be small, light and relatively economical.  
           [0008]    Another object is to provide a retractable cable reel which requires no commutation or sliding contacts.  
           [0009]    Another object is to provide factory assembled optical cable assemblies to lengths that can be conveniently varied.  
           [0010]    These and other objects and advantages of the present invention will become apparent to those skilled in the art after considering the following detailed specification, together with the accompanying drawings wherein: 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of a cable reel assembly of the present invention;  
         [0012]    [0012]FIG. 2 is an exploded view of the assembly of FIG. 1;  
         [0013]    [0013]FIG. 3 is an enlarged view of the present invention with the top housing thereof removed;  
         [0014]    [0014]FIG. 4 is a view similar to FIG. 3 of the cable reel of the assembly with the cable attached thereto;  
         [0015]    [0015]FIG. 5 is a greatly enlarged top cross-sectional view of the reel position maintaining releasable retention lever of the present invention;  
         [0016]    [0016]FIG. 6 is a perspective view of the assembly of the present invention with cable extending out of the same side of the assembly; and  
         [0017]    [0017]FIG. 7 is a side view of the present invention being used to vary the length between connectors of an optical cable. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    Referring to the drawings more particularly by reference numbers, number  100  in FIGS. 1 and 2 refers a retractable headset assembly  100  which as shown assembled in FIG. 1 and disassembled in FIG. 2. The assembly  100  includes a top housing portion  102 , and a bottom housing portion  104  having opposite openings  105  and  106  through its cylindrical side  107 . The two housing portions  102  and  104  when assembled define a generally cylindrical interior cavity  108 . A reel  110  having a closed side formed by a generally circular disk  112 , a generally cylindrical reel hub  113 , and an open side  114  is rotatably mounted in the interior cavity  108 . The hub  113  includes a pair of spaced slots  116  and  118  though which a central portion  120  of a multi-wire cable  122  is retained. This is shown in detail in FIGS. 3 and 4. The opposite ends  122   a  and  122   b  of the cable  122  extend through the opposite openings  105  and  106  and are normally connected respectively between the jack of a cell phone by means of plug  123   a  and a headset  123   b  therefor shown including a ear piece  124   a  and a microphone  124   b.  A coil spring  125  is connected between the hub  113  and a central, cylindrical retention post  126  extending from the bottom housing portion  104  by a hook  127  which engages the hub  113  at a slot  128 , to bias the reel  110  so that the reel winds up the cable  122  doubly there about. A central bearing surface  129  through the disk  112  centers the reel  110  on the post  126  for rotation thereabout. The normal position of the cable  122  is wound around the reel hub  113 . When a length of cable  122  is desired, pulling on either or both ends  122   a  and  122   b  of the cable  122  extends the cable  122  out of the openings  105  and  106 , keeping the housing portions  102  and  104  and the reel  110 , generally in the middle of the cable  122 .  
         [0019]    The edge  130  of the disk  112  includes a plurality of detents  132 . A releasable retention lever  134  (enlarged view in FIG. 5) pivoted to the lower housing portion  104  on post  135  includes a pawl  136  biased by spring  137  into the edge  130  to engage one of the detents  132 . The pawl  136  is restricted in motion range by engagement with a portion  144  of the cylindrical side  107  whereas the spring  137  acts between a spring retainer portion  146  upstanding from the bottom housing portion  104  and an interior abutment surface  148  of the retention lever  134 . This holds the reel  110  against the bias imposed thereon by the spring  125  so as to releasably maintain a given length of cable  122  unwound from the reel  110 . A retractor lever portion  150  of the releasable retention mechanism  134  extends beyond the cylindrical side  107 . When the portion  150  is depressed, the pawl  136  releases the detent  132  with which it is in contact and allows the spring  125  to rewind the cable  122  onto the reel  110 . Note that twice the amount of cable  122  is retracted and extends as the diameter of the hub  113 , reducing the rotation requirements of the coil spring  125 .  
         [0020]    As shown in FIG. 6, both ends  122   a  and  122   b  of the cable  122  may be extended out of the same side of the assembly  100 . This configuration is for use when the assembly includes a large quantity of cable from which it may hang.  
         [0021]    In addition to providing an electrical connection of variable length, the assembly  100  may be configured with optical cables  160  instead of electrical ones as shown in FIG. 7. In this way, standard length ranges of optical cables  160  with factory installed connectors  162  and  164  may be provided to connect optical devices. For example if an assembly  100  can retract fifty feet of optical cable, then assemblies  100  capable of accommodating distances between optical devices of zero to fifty feet, fifty to one hundred feet, one hundred to one hundred and fifty feet, and so on can be produced to eliminate cable takeup trays and yet not require field optical fiber cutting and connector attachment.  
         [0022]    Thus, there has been shown novel demodulation apparatus and demodulation method which fulfill all of the objects and advantages sought therefor. Many changes, alterations, modifications and other uses and applications of the subject invention will become apparent to those skilled in the art after considering the specification together with the accompanying drawings. All such changes, alterations and modifications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims that follow.