Abstract:
An LED street lamp includes a base having an end forming a connection head and an opposite end rotatably coupled to a rotatable LED lamp body. The lamp body includes therein heat pipes to which a flexible circuit board carrying LEDs is mounted. Multiple lamp components are connected in a cascade form to constitute the lamp body, whereby when the LEDs emit light, the heat generated can be dissipated away by the heat pipes. Further, each LED light source is set in a given direction according to a trough defined in the lamp component that receives the LED light source so that uniform and bright lighting can be obtained. The device is connectable to an existing street lamp in order to save the great expense for replacing the whole street lamp.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to an LED (Light-Emitting Diode) street lamp that is in compliancy with the existing street lamp specifications, such as E39/E40 or similar standards. 
       DESCRIPTION OF THE PRIOR ART 
       [0002]    With the years&#39; use and experience of street lamps, it is found that the best configuration of a street lamp is that shown in  FIG. 15  of the attached drawings, in which a curved metal hood  70  forms an upper portion of the lamp and a curved glass cover  71  is attached under the hood  70 . A socket  72  is arranged at an end inside the hood  70  and the cover  71  to receive an E39/E40 light bulb  90  to screw therein. A shaped post  73  extends from the lamp down to the ground to complete the structure of the street lamp. However, the light bulb  90  of the conventional street lamp emits light in a radiating fashion so that the light rays L 2  emitting from an upper portion of the light bulb  90  travels upward first to impinge the hood  70  and is then reflected down to the ground. This certainly deteriorates the brightness of such light rays. The light rays L 1  emitting from a lower portion of the light bulb  90  are spread with the radiating angle so that the brightness for the area exactly below the street lamp may not be good. This is certainly not an idea arrangement of lighting. A practical test reveals that the conventional street lamp shows a light efficiency of only around 40-60%. In addition, although the outside shape of the conventional street lamp is often of such a design as to render low wind resistance and dust- and rain-proofness, yet internal heat dissipation is often very poor. 
         [0003]    Recently, a variety of LED lighting devices have been developed and proposed. The LEDs is of such a characteristic as to emit light only frontward and rather than in a radiating form as that found in the light bulbs. Consequently, completely different accessories must be developed if the LEDs are to be used as street lamps and the equipment or facility of the conventional street lamp must thus be discarded. The whole system of the street lamp must be changed and this is extremely expensive and a waste also. Further, a known LED based street lamp is often constructed by arranging the LEDs in an array to serve a light source of the street lamp. This makes a limited area exactly below the street lamp sufficiently bright and a circumferential area is comparatively dim. The overall lighting is poor. This is a blind spot of the known LED lighting devices. 
       SUMMARY OF THE INVENTION 
       [0004]    The primary objective of the present invention is to provide a street lamp, which is constructed by combining heat pipes and lamp components in such a way that each heat pipe has a side surface to which LEDs are mounted so that the heat generated by the LEDs can e immediately dissipated away by the heat pipe to thereby overcome the issue of heat dissipation found in the conventional street lamp and also allows of the use of the existing street lamp to thereby reduce the cost. 
         [0005]    Another objective of the present invention is to provide an arrangement in which a base and a lamp body are allowed to rotate relative to each other and are thus usable in the existing lighting devices and allow of adjustment of light projection direction of the street lamp. Such an arrangement allows the street lamp according to the present invention to be usable in an existing street lamp (such as E39/E40 or similar standards) to provide a street lamp of which the direction of projection of LED light is adjustable. 
         [0006]    The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
         [0007]    Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view showing the present invention. 
           [0009]      FIG. 2  is an exploded view showing a base and a lamp body according to the present invention. 
           [0010]      FIG. 3  is an exploded view showing spatial relationship of the lamp body according to the present invention. 
           [0011]      FIG. 4  is an exploded view showing a base, a rotary seat, and an end cover according to the present invention. 
           [0012]      FIG. 5  is an end view showing a lamp component according to the present invention. 
           [0013]      FIG. 6  is a perspective view, partly sectioned, showing spatial relationship of the present invention. 
           [0014]      FIG. 7  is a cross-sectional view showing the condition where the present invention is mounted to an existing street lamp with the lamp body being rotatably set at the optimum position. 
           [0015]      FIG. 8  is a cross-sectional view illustrating light projection of the present invention mounted to an existing street lamp. 
           [0016]      FIG. 9  illustrates a lamp component according to a second embodiment of the present invention. 
           [0017]      FIG. 10  is an exploded view of the second embodiment of the present invention, illustrating equivalent replacement of the lamp component. 
           [0018]      FIG. 11  is a perspective view, partly sectioned, of the second embodiment of the present invention. 
           [0019]      FIG. 12  is an exploded view of a third embodiment of the present invention, illustrating modification of heat pipe. 
           [0020]      FIG. 13  is a cross-sectional view of the third embodiment of the present invention, illustrating the combination of heat pipes and lamp components. 
           [0021]      FIG. 14  is a perspective view showing the third embodiment of the present invention in an assembled form. 
           [0022]      FIG. 15  is a schematic view illustrating a conventional street lamp. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
         [0024]    With reference to the drawings and in particular to  FIGS. 1 ,  2 , and  4 , the present invention comprises the following components: 
         [0025]    A base  10  receives and retains therein basic circuit components (not shown). The base has an end forming a connection head  11  and an opposite end forming a receiving chamber  12 . The receiving chamber  12  has a circumferential wall forming at least one sideway hole  13 . A fastener  14  (such as a screw) is received through the sideway hole  13  for fastening purposes. 
         [0026]    Referring to  FIGS. 2 and 4 , a rotary seat  20  is mounted inside the receiving chamber  12  of the base  10  and has a circumferential surface forming a circumferential groove  21 . The circumferential groove  21  is set in registration with the sideway hole  13  of the receiving chamber  12 . The rotary seat  20  has an outer end surface that is raised to form ribs  22 . In the embodiment illustrated, the ribs  22  collectively define an X shape, but are not limited to such a shape. An end of the X-shape of the ribs  22  is flattened to form a planar positioning section  221 . Further, the rotary seat  20  forms a central bore  23 . 
         [0027]    Referring to  FIGS. 2 and 3 , a lamp body  30  comprises a support post  31  and a plurality of heat pipes  33  that collectively constitute a main framework of the lamp body  30 . The heat pipes  33  forms, on least at a side surface (namely the outside surface), a flat surface  331  and a flexible circuit board  332  (such as a flexible print circuit, FPC) is mounted to the flat surface  331 . The flexible circuit board  332  comprises a plurality of spaced LED-based light emission bodies  351 . Each of the light emission bodies  351  is used in combination with a lens assembly  352  to form a lighting module  35  (see  FIG. 3 ). 
         [0028]    As shown in  FIGS. 2 ,  5 , and  6 , a plurality of lamp components  32  is provided, each having a form of a circular or an annular structure having a circumferential surface forming a plurality of troughs  324 , which provide spaces for respectively accommodating the lighting modules  35 . To prevent any undesired waste of light emitting from the street lamp, the troughs  324  are generally arranged at two lateral side portions and a bottom portion of each of the lamp component, whereby the lamp component  32  has a portion (namely the top portion) where no trough  324  is formed in a top portion and instead a bearing surface  323  is formed for bearing a retention board  40  that is fixed in position by fasteners  41 . Each of the lamp components  32  forms, centrally, a guide channel  321  through which the support post  31  extends or is inserted, and also forms a plurality of through holes  322  in a circumferential edge portion to receive the heat pipes  33  therethrough 
         [0029]    As shown in  FIGS. 2 ,  3 , and  6 , an end cover  34 , which can be of a configuration similar to the lamp components  32  or can be simply replaced by one of the lamp component  32 , forms a guide channel  341  through which the support post  31  extends or is inserted in a center thereof and a plurality of insertion cavities  342  to receive and retain the heat pipes  33 . 
         [0030]    The retention board  40  is positioned on the positioning section  221  of the rotary seat  20  and the bearing surface  323  of the lamp component  32  and is fixed by the fasteners  41  (such as screws), whereby the support post  31 , the lamp components  32 , the heat pipes  33 , and the end cover  34  are all assembled or fixed together to constitute the lamp body  30 , which is rotatable with the rotary seat  20 . 
         [0031]    When the present invention is assembled to a socket  72  of a conventional street lamp shown in  FIG. 15 , as illustrated in  FIG. 7  (also see  FIG. 6 ), the rotary seat  20  that is mounted inside the base  10  has a circumferential surface forming a circumferential groove  21  and is supported in position by fasteners  14  extending through the base  10  so that the lamp body  30  can be rotated and angularly moved with the rotary seat  20  by any desired angle θ. As a result, as shown in  FIG. 8 , the light can be angularly set to irradiate a large area below the street lamp. Since no lighting module  35  is set in a direction toward the hood  70 , no light is emitted in such a direction and thus no light is wasted. 
         [0032]    Referring to  FIG. 9 , a structure of a second embodiment according to the present invention is shown, in which the lamp component  60  comprises a centrally located guide channel  61  and a bearing surface  63  formed in a top portion thereof. However, each of the through holes  621  for the heat pipes and each of the troughs  622  for the lighting modules are combined to form a single inwardly recessed sideway slot  62  that is in communication with the outside, whereby the respective heat pipe  33  and the respective lighting module  35  can be directly inlaid in the sideway slot  62  of the lamp component  60 . The overall structural arrangement is illustrated in  FIGS. 10 and 11  and it preserves the convenience of use and maintains the feature of the present invention. 
         [0033]    Referring to  FIG. 2 , a heat dissipation device  80 , which can be of any of various means of heat dissipation, such as heat dissipation fins or a heat dissipation fan, can be arranged at an end of the lamp body  30  and coupled to the heat pipes  33  to provide improved heat dissipation. 
         [0034]    Referring to  FIGS. 12 and 13 , a structure of a third embodiment of the present invention is shown, in which the lamp body  50  comprises a support post  51  mounted at a center thereof and heat pipes  53  that are curved structures arranged at a circumferential portion thereof. In the embodiment illustrated, the heat pipes are of a U-shape having an outside surface forming a flattened surface  531  to which a flexible circuit board  532  is mounted. The flexible circuit board  532  comprises a plurality of spaced LED-based light emission bodies  351 , each of which is in combination with a lens assembly  352  to form a lighting module  35 . 
         [0035]    A plurality of lamp components  52  is attached, in a cascade form, to the support post  51  and is of the circular or annular structure described above, in which a guide channel  521  is formed in a center thereof and troughs  522  are formed in a side surface thereof. Also, a top portion of each lamp component forms a bearing surface  523 . However, a receiving recess  524  is formed in an end surface of the lamp component to receive the heat pipe  53 . Such a structure preserve the original design in such a way that heat generated by the lighting modules  35  are directly conducted off by the heat pipes  53  and transmitted to the ends of the heat pipes. With such an arrangement, the retention board  400  may be structured to receive ends of the heat pipes  35  to extend therethrough without affecting the original function thereof. Referring to  FIG. 14 , a heat dissipation device  80 , which can be of any of various means of heat dissipation, such as heat dissipation fins or a heat dissipation fan, can be arranged at the portions of the heat pipes  53  extending outside the lamp components  52  to provide improved heat dissipation. 
         [0036]    The retention board  40  that is shown for example in  FIG. 1  is not subjected to any specific limitation in shape and can be of any desired shape, not limited to the rectangular shape illustrated in the drawings and, instead, a tubular or curved configuration may be adopted. 
         [0037]    Referring to  FIGS. 8 ,  9 , and  13 , the lamp component  23 ,  52 ,  60  illustrated comprises lighting modules  35  arranged at a circumferential surface thereof for projecting lights in various directions, whereby the light sources are arranged in a spaced manner by predetermined intervals. Such a distributed arrangement of multiple arrays projects light in a direction away from the hood and toward the site where uniform lighting is desired so that bright and uniform lighting may be obtained. 
         [0038]    It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
         [0039]    While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.