Abstract:
An adjustable lighting device having a main body, a light generation device inserted into a receptacle, a movable lens, a base electrically connected to the light generation device, and an adjustor cover rotatably mounted to and covering the outside of the main body so that rotation of the adjustor cover causes the lens to extend/retract within the receptacle so that the extension/retraction of the lens can be controlled by the rotation of the adjustor cover for realizing focus adjustment.

Description:
PRIOR APPLICATIONS 
       [0001]    This application is a substitute application that replaces the application previously filed on May 8, 2008, Ser. No. 12/149,843. The previous application went abandoned for failure to timely pay the filing fee. The content of this application is exactly the same as the previously filed application accept for the fact that the abstract has been amended to comply with filing requirements. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to an adjustable lighting device, and in particular to a lighting device comprising a combination of a main body, a light generation device, a lens, a base, and an adjustor cover for providing the advantages of focus adjustability and easy and secured assembling and applicable to various lighting device and the likes. 
       BACKGROUND OF THE INVENTION 
       [0003]    Lighting can be classified as regular lighting and spot lighting. The former is for a wide lighting of a large area, while the latter is for concentrated lighting in a small, spot-like area. 
         [0004]    For example, the wide lighting for a large area includes street lamps, post lamps in for example a park, or ceiling mounted pendant lighting. The purpose of the wide lighting is to illuminate the whole area with the least number of lighting devices. 
         [0005]    Contrary to the regular lighting, the spot lighting is to condense light beam onto a specific spot or article to distinguish the spot or the article. For example, firstly, an exhibition lamp that is provided for the purposes of exhibition must condense the light spot on an exhibited article to distinguishably show the article. Secondly, spot lighting can be used for interior decoration for the modern interior decoration, except the aspect of hardware decoration, include an aspect of visual impression that is presented by lighting inside the house, of which the most commonly known measure is to condense and project light on for example a wall, an ornamentation or a dinning table so as to provide excellent visual and lighting effect with the combination of hardware decoration and the lighting. 
         [0006]    However, some of the conventional lighting devices are not provided with the function of light condensation and/or focusing and most of the conventional lighting devices are not of the feature of focus adjustability. The former drawback make the use of the lighting device inconvenience or even impractical, while the latter drawback causes a situation of out of focusing of the projecting light on an irradiated article for the distance between the light source and the irradiated article can be various and cannot be accommodated by the lighting if no focus adjustability can be available. 
         [0007]    Thus, the present invention is aimed to overcome the above discussed drawbacks. 
       SUMMARY OF THE INVENTION 
       [0008]    An objective of the present invention is to provide an adjustable lighting device comprising a main body forming, in a front end thereof, a first receptacle in which a light generation device and a lens are received and an adjustor cover mounted to and covers the front end of the main body and having an inner circumference forming a threading engagement with an outer circumference of the lens to effect adjustment of focus by the extension/retraction of the lens driven by the rotation of the adjustor cover and also to provide easy and secured assembling, whereby the present invention enhances practicability. 
         [0009]    Another objective of the present invention is to provide an adjustable lighting device comprising a base that is constructed as a conventional light bulb base and thus, the convenience of directly mounting to a regular bulb socket for operation can be realized, whereby the present invention enhances convenience. 
         [0010]    A further objective of the present invention is to provide an adjustable lighting device, wherein a plurality of heat dissipation fins circumferentially surround the main body and a plurality of heat dissipation channels are respectively formed in an adjustor cover and an enclosure that surround the main body so that enhanced heat dissipation can be realized, whereby the present invention enhances heat dissipation performance. 
         [0011]    To realize the above objectives, in accordance with the present invention, an adjustable lighting device is provided, comprising a main body, a light generation device, a lens, a base, and an adjustor cover. The main body has a first end forming a first receptacle. The light generation device comprises a light-emitting diode based light emission element and is fixed in the first receptacle. The lens is movably received in the first receptacle and has an outer circumference forming an external thread. The base is mounted to an opposite, second end of the main body and is in electrical connection with the light emission element. The adjustor cover forms an opening having an internal thread. The adjustor cover is rotatably mounted to and covers outside of the main body with the internal thread in engagement with the external thread of the lens. Thus, rotation of the adjustor cover causes the lens to extend/retract within the first receptacle. As such, advantages including light condensability, focus adjustability, easy and secured assembling, and direct applicability to a regular bulb socket are realized for ensuring practicability and convenience. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof with reference to the drawings, in which: 
           [0013]      FIG. 1  is a perspective view of an adjustable lighting device constructed in accordance with the present invention; 
           [0014]      FIG. 2  is a cross-sectional view of the adjustable lighting device in accordance with a first embodiment of the present invention; 
           [0015]      FIG. 3  is an enlarged view of encircled portion A of  FIG. 2 ; and 
           [0016]      FIG. 4  is a cross-sectional view illustrating a situation after the adjustment of the adjustable lighting device of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    With reference to the drawings and in particular to  FIGS. 1-4 , An adjustable lighting device constructed in accordance with the present invention comprises a main body  1 , a light generation device  4 , a lens  3 , a base  2 , and an adjustor cover  6 . 
         [0018]    The main body  1  has a first end forming a first receptacle  11 . The light generation device  4  comprises a light emission element  42 . The light generation device  4  is fixed in the first receptacle  11 . The lens  3  is movably received in the first receptacle  11 . The lens  3  has an outer circumference forming an external thread  31 . The base  2  is mounted to an opposite, second end of the main body  1  and the light generation device  42  is electrically connected to the base  2 . The adjustor cover  6  forms an opening  61  forming an internal thread  611 . The adjustor cover  6  is movably mounted to and encloses an outside surface of the first end portion of the main body  1 . The internal thread  611  of the adjustor cover  6  is in threading engagement with the external thread  31  of the lens  3  whereby rotation of the adjustor cover  6  brings on extension/retraction of the lens  3  within the first receptacle  11  to effect focus adjustment. 
         [0019]    The light generation device  4  comprises a condensation cap  41 , which is fixed inside the first receptacle  11 . The light emission element  42  is fixed in the condensation cap  41  (and is located at a center of the condensation cap  41  in the embodiment illustrated). The lens  3  forms a cavity  32  in which the condensation cap  41  is received. The cavity  32  has an inside surface  321  forming at least one guide slot  322  to which the condensation cap  41  forms at least one corresponding projection  411 , whereby the at least one guide slot  322  of the lens  3  is fit over and slidable along the at least one projection  411  of the condensation cap  41  to effect guidance of the sliding movement thereof. The present invention further comprises an enclosure  7  that encloses outside the main body  1  and extends between the adjustor cover  6  and the base  2  with adjacent portions of the enclosure  7  and the base  2  partially overlapping each other. In the embodiment illustrated, the adjacent portion of the enclosure  7  is positioned on and overlaps the adjacent portion of the base  2 . The enclosure  7  covers the main body  1  except those portions associated with the adjustor cover  6 , the lens  3 , and the base  2 . The adjustor cover  6  and the enclosure  7  are both provided with a plurality of heat dissipation channels  64 ,  73  (as shown in  FIG. 1 ). The main body  1  forms a circumferentially extending retention groove  13 . The end of the adjustor cover  6  that is opposite to the opening  61  and the end of the enclosure  7  that is adjacent to the end of the adjustor cover  6  that is opposite to the opening  61  are both formed with a pawl  62 ,  71 , which is received in and engages the retention groove  13 . The end of the adjustor cover  6  that is opposite to the opening  61  and the end of the enclosure  7  that is adjacent to the end of the adjustor cover  6  that is opposite to the opening  61  are respectively provided with a positioning protrusion  63  and a positioning slot  72 , wherein the positioning protrusion  63  is fit into the positioning slot  72  for positioning purposes. The light emission element  42  can be for example a regular light bulb or a light-emitting diode as illustrated in the present embodiment. The lighting device of the present invention further comprises a power conversion device  8 . The second end of the main body  1  forms a second receptacle  12  in which the power conversion device  8  is received. The power conversion device  8  is electrically connected between the light emission element  42  and the base  2  by means of connection lines  81  whereby the power conversion device  8  converts an external power into electrical power applicable to the light-emitting diode. The main body  1  comprises a plurality of heat dissipation fins  10 , each having a first end and an opposite second end respectively forming a first cutoff  101  and a second cutoff  102 . The heat dissipation fins  10  are arranged in a circumferentially surrounding manner with the first cutoffs  101  together forming the first receptacle  11  of the main body  1  and the second cutoffs  102  forming the second receptacle  12  of the main body  1 . The base  2  can be a base of a conventional light bulb. 
         [0020]    The feature of the adjustable lighting device in accordance with the present invention is that the main body  1  of the lighting device of the present invention forms, in a first, front end thereof, a first receptacle  11  in which a light generation device  4  and a lens  3  are received and an adjustor cover  6  is mounted to and covers the front end of the main body  1  and has an inner circumference forming a threading engagement with an outer circumference of the lens  3  to effect adjustment of focus by the extension/retraction of the lens  3  driven by the rotation of the adjustor cover  6  and also to provide easy and secured assembling. With the base  2  being constructed as a conventional light bulb base, the convenience of directly mounting to a regular bulb socket (not shown) for operation can be realized. With a plurality of heat dissipation fins  10  circumferentially surrounding the main body  1  and also with a plurality of heat dissipation channels  64 ,  73  respectively formed in the adjustor cover  6  and the enclosure  7  that surround the main body  1 , enhanced heat dissipation can be realized. Further, with the plurality of heat dissipation channels  64  defined in the adjustor cover  6 , hand holding and rotation of the adjustor cover  6  can be ensured. With the guide slot  322  defined in the inside surface  321  of the lens  3  and the corresponding projection  411  formed on the condensation cap  41 , the guide slot  322  of the lens  3  is fit over and slidable along the projection  411  to ensure guidance of the sliding movement thereof for extension/retraction of the lens  3  so that the extension/retraction of the lens  3  can be done in a more stable manner. To conclude, the present invention provides advantages including light condensability, focus adjustability, easy and secured assembling, direct applicability to a regular bulb socket, and enhanced heat dissipation and thus ensures practicability, convenience, and better heat dissipation. 
         [0021]    Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.