Patent Publication Number: US-8534863-B2

Title: LED lamp with hermetical end holders

Description:
BACKGROUND 
     1. Technical Field 
     The disclosure relates to LED (light emitting diode) lamps, and particularly to an LED lamp with end holders preventing hydrosphere or humidity from entering the LED lamp. 
     2. Description of the Related Art 
     As light emitting diodes (LEDs) come with the features of low power consumption, power saving, long service time, small size and quick response etc., LED lamps, such as LED tubes, gradually substitute traditional light sources. Generally, an LED tube includes a lamp shell to receive an LED module therein and a power module mounted at an exterior of the lamp shell. Hydrosphere will enter the lamp shell to destroy the LED module or directly destroy the power module. 
     What is needed, therefore, is an LED lamp which can overcome the limitations described. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric, assembled view of an LED lamp in accordance with an exemplary embodiment of the disclosure. 
         FIG. 2  is an exploded view of the LED lamp of  FIG. 1 . 
         FIG. 3  is an exploded view of one holder of the LED lamp of  FIG. 2 . 
         FIG. 4  is a cutaway view of a part of the assembled LED lamp of  FIG. 1 , shown from a different aspect. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will be made to the drawing figures to describe the present LED lamp in detail. 
     Referring to  FIGS. 1-2 , an LED lamp in accordance with an exemplary embodiment of the disclosure is illustrated. The LED lamp includes a frame  10 , an LED module  20 , a power module  30 , an envelope  40 , and two holders  50  respectively engaged with two ends of the frame  10 . 
     The frame  10  is integrally formed of a metal with good heat conductivity such as aluminum or an aluminum alloy as a single piece. In this embodiment, the frame  10  is formed by aluminum extrusion. The frame  10  includes a tube  11  and a reflector  14  integrally extending from the tube  11 . 
     The tube  11  is hollow, elongated and has a rectangular cross section. The tube  11  includes a supporting plate  12  at a bottom thereof. The supporting plate  12  defines two connecting holes  16  each near a corresponding holder  50 . A top of the tube  11  defines two screw holes  18  near two ends thereof. An interior of the tube  11  functions an electrical section  300  to receive the power module  30  therein. 
     The reflector  14  extends from opposite lateral sides of a bottom of the supporting plate  12 . The reflector  14  is elongated. An inside surface of the reflector  14  is curved, and coated with reflective material. The envelope  40  tightly engages with a bottom of the reflector  14 . The supporting plate  12 , the reflector  14  and the envelope  40  cooperatively defines an optical section  200  to receive the LED module  20  therein. 
     The LED module  20  includes an elongated printed circuit board (not labeled) and a plurality of LEDs (not shown) mounted at a bottom surface of the printed circuit board. The LED module  20  is received in the optical section  200  and fixed to a bottom surface of the supporting plate  12 . Light emitted from the LED module  20  is reflected by the reflector  14  and through the envelope  40  to an external environment of the LED lamp. 
     The power module  30  is received in the electrical section  300  of the tube  11  and mounted on an upper surface of the supporting plate  12 . The power module  30  provides drive power, control circuit and power management for the LED module  20 . A plurality of electrical wires (not shown) extends through the connecting holes  16  of the supporting plate  12  to electrically connect the power module  30  and LED module  20  together. Since the connecting holes  16  are defined in an inner of the LED lamp to reduce holes between the LED lamp and the environment, a hermetic capability of the LED lamp is enhanced. 
     The holders  50  are hermetically engaged with two ends of the frame  10 , respectively. Each of the holders  50  includes an upper first cover  52  engaged with the electrical section  300  and a lower second cover  54  engaged with the optical section  200 . The first cover  52  and the second cover  54  of each holder  50  are separately manufactured and then coupled together. 
     Referring to  FIG. 3 , each of the first covers  52  includes a vertical first side plate  521 , a first wall  522 , and a second wall  523 . The first side plate  521  has a profile corresponding to the cross section of the tube  11 . The first wall  522  extends from an outer edge of the first side plate  521  towards the tube  11 . The second wall  523  extends from the first wall  522  towards the tube  11 . Each of the first wall  522  and the second wall  523  has a generally U-shaped cross section, with bottom sides thereof being open. A step portion  525  is formed between the first wall  522  and the second wall  523 . Two coupling flanges  524  respectively extend from opposite sides of the bottoms of the first wall  522  and the second wall  523  towards each other. The first and second walls  522 ,  523  form two ribs  527  at inner lateral sides (not labeled) thereof. Each of the ribs  527  has a gradually increased thickness in respective to the corresponding inner lateral side along a direction from the second wall  523  to the first wall  522 . The second wall  523  defines a screw hole  528  in a top thereof aligned with one screw hole  18  of the tube  11 . The screw  70  can extend through the screw hole  528  into the screw hole  18 . Also referring to  FIG. 2 , the first side plate  521  of one first cover  52  defines a through hole  526 . A waterproof connecter  60  is engaged in the through hole  526  for wires extending therethrough to connect the power module  30  to an external power source (not shown). 
     The second cover  54  includes a second side plate  541 , an outer wall  542 , and an inner wall  543 . The outer wall  542  connects to an outer edge of the second side plate  541  and is perpendicular to the second side plate  541 . The inner wall  543  perpendicularly extends from the second side plate  541  towards the reflector  14 . The inner wall  543  is spaced from the outer wall  542  and surrounded by the outer wall  542 . The second side plate  541  has a profile similar to a cross section of the reflector  14 . The outer wall  542  defines a cutout  540  at a top thereof near the reflector  14 . The second cover  54  includes a first baffling plate  544  and a second baffling plate  545  extending outwards from a top of the second side plate  541  and outside the cutout  540 . The second baffling plate  545  is spaced from the outer wall  542  to define two grooves  547  therebetween. The first baffling plate  544  defines two slits  546  respectively communicating with the grooves  547  for receiving the coupling flanges  524  of the first cover  52 . 
     Referring to  FIG. 4 , in assembly, the LED module  20  is mounted in the optical section  200 , and the power module  30  is mounted in the electrical section  300  of the tube  11 . The second covers  54  of the holders  50  mounted at two ends of the optical section  200 . Ends of the reflector  14  and the envelope  40  are sandwiched between the outer wall  542  and the inner wall  543  and abut against the second side plates  541 . The first covers  52  are mounted at ends of the electrical section  300  and coupled to the second covers  54 . The coupling flanges  524  are received in the slits  546  of the second covers  54  and abut against the supporting plate  12  of the tube  11 . The second walls  523  extend into the tube  11 . The ends of the tube  11  abut against the step portions  525  of the first covers  52 . The electrical wires of the power module  30  extend through the waterproof connecter  60  engaged in the through hole  526  of the first cover  52 . Finally, each of the screws  70  is engaged in the screw holes  18  of the tube  11  and the screw holes  528  of the first cover  52  to fasten the holder  50  on the frame  10 . 
     Since the first cover  52  and the second cover  54  are separately manufactured and tightly enclose the ends of the optical section  200  and the electrical section  300 , the cost for manufacturing the holders  50  can be considerably reduced. Additionally, one of the holders  50  is mounted with the waterproof connecter  60  for extension of the electrical wires, whereby external hydrosphere can be prevented from entering the LED lamp. 
     It is to be further understood that even though numerous characteristics and advantages have been set forth in the foregoing description of the embodiment(s), together with details of the structures and functions of the embodiment(s), the disclosure is illustrative only; and that changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.