Patent Abstract:
A wire winding device includes a case, a reel received in the case for winding a wire thereon, a restricting member for restricting/releasing the reel, and a resilient member for interconnecting the case and the reel and rotating the reel and being movable with reel in an axis direction of the reel when the reel starts to rotate.

Full Description:
FIELD OF THE INVENTION 
   The present invention relates to wire winding devices, and particularly to a wire winding device with a spring loaded retractable wire reel. 
   DESCRIPTION OF RELATED ART 
   Wires are necessary parts in consumer electronics, such as computers, modems, telephones, and fax machines, and are often used for connecting two or more such devices. However, if the wires are too long they will often become tangled, causing great inconvenience. 
   To avoid this shortcoming, a kind of automatic wire winding device has been proposed. The wire winding device generally includes a housing, a winding disk or reel, a scroll spring, and a swing plate. The winding disk is a circular disk and received in the housing. The scroll spring is positioned in the housing and includes a fastening end fastened with the winding disk so that the scroll spring and the winding disk can be joined. When the winding disk turns, the scroll spring stores energy. In practical use, the wire is pulled out directly from the housing storing energy in the spring. When the swing plate is driven to release the winding disk, the stored energy is released and the spring recoils urging the reel to rotate, thus rewinding the wire. 
   However, the wire winding device is complicated because an additional actuator, such as a button, is needed to drive the swing plate, and is inconvenient because the user has to operate the additional actuator to rewind the wire. 
   What is needed, therefore, is a wire winding device with simple and convenient properties. 
   SUMMARY OF THE INVENTION 
   A wire winding device includes a case, a reel received in the case for winding a wire thereon, a restricting member for restricting/releasing the reel, and a resilient member for interconnecting the case and the reel and rotating the reel and being movable with reel in an axis direction of the reel when the reel starts to rotate. 
   Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded, isometric view of a wire winding device in accordance with a preferred embodiment; 
       FIG. 2  is a top view of a first case of  FIG. 1 ; 
       FIG. 3  is an enlarged, exploded, isometric view of part of the first case of  FIG. 1 ; 
       FIG. 4  is an enlarged, isometric view of a reel of  FIG. 1 ; 
       FIG. 5  is an enlarged, isometric view of a resilient lock of  FIG. 1 ; 
       FIG. 6  is an isometric view of the wire winding device of  FIG. 1 , with a digital camera being mounted therein; and 
       FIG. 7  is an isometric view of the wire winding device of  FIG. 6 , with the digital camera being drawn out therefrom. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In the following embodiment, a wire winding device applied in a digital camera is used as an example for illustration. It is noted that the wire winding device in the embodiment may be also applied in a computer, a modem, a telephone or any other electronic apparatus. 
   Referring to  FIG. 1 , a wire winding device in accordance with a preferred embodiment includes a housing  12 , a reel  14 , a scroll spring  16 , and a resilient lock  18 . The housing  12  includes a first case  20  and a second case  22  coupled to the first case  20 . The reel  14 , the scroll spring  16 , and the resilient lock  18  are accommodated in the housing  12 . 
   Referring also to  FIGS. 2 and 3 , the first case  20 , which defines an elongated recess portion  24  therein, includes a first shoulder  26 , a second shoulder  28 , a third shoulder  30 , a fixing sheet  32 , and an L-shaped sheet  34 . The first shoulder  26 , the second shoulder  28  and the third shoulder  30  are spaced from and substantially parallel to each other, and arranged in series in the recess portion  24  along its longitudinal direction. A plurality of fixing holes  35  are respectively defined in the first shoulder  26 , the second shoulder  28 , and the third shoulder  30  for receiving the reel  14  and the resilient lock  18 . The first shoulder  26  includes a wedge portion  38 . A first receiving groove  40  and a second receiving groove  42  are defined in the first shoulder  26  and arranged at two opposite sides of the wedge portion  38 . A sliding channel  44  is defined through the wedge portion  38  for communicating the first receiving groove  40  and the second receiving groove  42 . A first acute angle α is defined between a center-line direction of the sliding channel  44  and an axial direction of the reel  14 . The sliding channel  44  divides the wedge portion  38  into two parts named as a first wedge subportion  46  and a second wedge subportion  48 . The first wedge subportion  46  and the second wedge subportion  48  are staggered along the axial direction of the reel  14 . The first wedge subportion  46  includes a first inclined surface  50  adjacent to the first receiving groove  40  and oriented such that a lower end of the first inclined surface  50  is nearest the first receiving groove  40 . The second wedge subportion  48  includes a second inclined surface  52  adjacent to the second receiving groove  42  and oriented such that a lower end of the second inclined surface  52  is nearest the second receiving groove  42 . A second acute angle β is defined between the first inclined surface  50  and a supposed plane  54  perpendicular to the axial direction of the reel  14 . Between the second inclined surface  52  and the plane  54 , another second acute angle β is also defined. At least one end of the fixing sheet  32  is secured to the recess portion  24 . A first interspace (not labeled) is defined under the fixing sheet  32  and between the fixing sheet  32  and the recess portion  24  allowing a free end  55  of the scroll spring  16  to be inserted therethrough. The L-shaped sheet  34  interconnects the second shoulder  28  and the third shoulder  30  and includes a first baffle sheet  56  and a second baffle sheet  58  perpendicularly extending from the first baffle sheet  56 . 
   Referring also to  FIG. 4 , the reel  14  includes a first end portion  60  supported by the first shoulder  26  and an opposite end portion  62  supported by the second shoulder  28 . Three guiding teeth  64  extend from the outer circumference of the reel  14  in equal radians and are adjacent to the first end portion  60 . The three guiding teeth  64  can be rotated and moved into the first receiving groove  40  or the second receiving groove  42  via the sliding channel  44 . Each guiding tooth  64  includes two opposite first sides  66  and two opposite second sides  68 . Each first side  66  is perpendicular to the axial direction of the reel  14 . A third acute angle γ is defined between each second side  68  and the axial direction of the reel  14 . The third acute angle γ is substantially equal to the first acute angle α, or is less than or equal to the second acute angle β. Three first blocking sheets  70  extend from an axis of the reel  14  in equal radians and are arranged at the second end portion  62 . 
   Referring also to  FIG. 5 , the resilient lock  18  includes a shaft  72 , a second blocking sheet  74 , and a resilient sheet  76 . The second blocking sheet  74  and the resilient sheet  76  substantially oppositely extend from a circumference of the shaft  72 . Two ends of the shaft  72  are inserted into the corresponding fixing holes  35 . A location of the second blocking sheet  74  is closer to one end of the shaft  72  than to another end of the shaft  72  so that a second interspace (not labeled) is defined between the second shoulder  28  and the second blocking sheet  74 . A length of the second interspace is appreciably greater than that of each first blocking sheet  70  so that there is no interference between each first blocking sheet  70  and the second blocking sheet  74  before any one of the three guiding teeth  64  enters the second receiving groove  42 . A width of the second blocking sheet  74  is greater than that of the first baffle sheet  56  so that the second blocking sheet  74  overlaps an edge of the first baffle sheet  56 . The second blocking sheet  74  is hindered by the first baffle sheet  56  whilst the resilient sheet  76  resiliently resists the second baffle sheet  58  so that the second blocking sheet  74  can be rotated about the shaft  72  between the first baffle sheet  56  and the second baffle sheet  58 . 
   Referring also to  FIG. 6 , most of the scroll spring  16  is wound around the first end portion  60  of the reel  14  besides the free end  55  being inserted through the first interspace under the fixing sheet  32 . The scroll spring  16  can thus interconnect the reel  14  and the first case  20 . A width of the scroll spring  16  is less than a length of the first interspace so that there is sufficient distance for the scroll spring  16  to move along a longitudinal direction of the fixing sheet  32 . 
   Referring also to  FIG. 7 , a binding of a digital camera  78  with a wire  80  tailing thereafter and the wire winding device according to the preferred embodiment is illustrated. In use, the wire  80  is received in the first case  20 , and most of the wire  80  is wound about the reel  14 . The first blocking sheet  70  separates from the second blocking sheet  74 . At least one guiding tooth  64  is inserted in the first receiving groove  40 . The scroll spring  16  is in a relaxed state. When the digital camera  78  is drawn out from the first case  20 , the wire  80  pulls the reel  14  to rotate, the scroll spring  16  is tightened thereby storing energy. Axial and radial motions of the reel  14  are inevitable because of normal manufacturing tolerances of the reel  14  and the fixing holes  35  and friction between the reel  14  and the wire  80 . One of the three guiding teeth  64  can thus rotate and move to contact the side of the second wedge subportion  48 . Here, the first wedge subportion  46  blocks and forces the guiding tooth  64  to enter the sliding channel  44 . This guiding tooth  64  is supposed as a first guiding tooth. The remaining two guiding teeth  64  which follow the rotation of the first guiding tooth  64  are supposed as a second guiding tooth  64  and a third guiding tooth  64 . The second guiding tooth  64  rotates and moves to engage with the second inclined surface  52 . The reel  14  continues to rotate and move, and then at least one of the guiding teeth  64  enters the second receiving groove  42 . One of the three first blocking sheets  70  rotates and moves to contact the second blocking sheet  74 . The resilient sheet  76  resiliently resists the second baffle sheet  58 . The one of the first blocking sheets  70  is thus baffled by the second blocking sheet  74 . 
   If a desired length is wanted, the wire  80  is continuously pulled until the desired length is exposed. The three guiding teeth  64  rotate in the second receiving groove  42 . The first blocking sheets  70  rotate to overcome a resilient force produced by the resilient sheet  76 . This causes the second blocking sheet  74  to rotate away to get out of the way for the first blocking sheets  70 . The reel  14  can thus be continuously rotated and the wire  80  can be pulled out. When a user slowly stops pulling the wire  80  out, the first blocking sheet  70  is baffled by the second blocking sheet  74 , thus the wire  80  is prevented from being retracted. 
   When it is desired that the wire  80  be retracted, the user need only pull the wire  80  again a short distance causing the reel  14  to rotate at a certain angle, and then the user releases the wire  80  immediately. The scroll spring  16  then causes the reel  14  to rotate in a direction that retracts the wire  80 . Reversed axial and radial motions of the reel  14  are inevitable because of normal manufacturing tolerances of the reel  14  and the fixing holes  35 , and because of the resilient force of the scroll spring  16  applied to the reel  14 . The reel  14  therefore shifts a short distance in the axis direction thereof to separate the first blocking sheet  70  from the second blocking sheet  74  in the axis direction before the first blocking sheet  70  rotates to engage with the second blocking sheet  74 . The three guiding teeth  64  return from the second receiving groove  42  to the first receiving groove  40  via the sliding channel  44  and the first inclined surface  50 . Then, the reel  14  rotates freely in the first receiving groove  42  until the wire  80  is entirely rewound. 
   In alternative embodiments, the numbers of the guiding teeth  64  and the first blocking sheets  70  are not limited to three, the corresponding numbers may be two, four or other. In addition, a connection between the scroll spring  16  and the first case  20  are not limited to a usage of the fixing sheet  32 . A long slot may be defined in the scroll spring  16  near to the free end  55 . A pin or screw may be inserted through the long slot and fixed in the recess portion  24 . Furthermore, a plurality of blocking grooves can be defined in the circumference of the reel  14  instead of the first blocking sheets  70  to detachably receive the second blocking sheet  74 . The resilient lock  18  may include a blocking sheet and a resilient sheet fixed with the blocking sheet. One end of the resilient sheet is secured in the second baffle sheet  58 , while one end of the blocking sheet selectively blocks the first blocking sheets  70  or is received in the blocking grooves. Still further, the shaft  72  and the third shoulder  30  may be omitted. Moreover, the wire winding device may also be applied in a keyboard, a mouse, a telephone or the like, and the housing  12  may be directly adopted as a shell of the keyboard, the mouse, the telephone or the like. 
   It is believed that the present invention and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.

Technology Classification (CPC): 1