Patent Publication Number: US-6215249-B1

Title: Fluorescent lamp assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a fluorescent lamp assembly, more particularly to a fluorescent lamp assembly that has lamp switches for controlling activation of sets of fluorescent lamps. 
     2. Description of the Related Art 
     FIG. 1 illustrates a first conventional fluorescent lamp assembly for mounting on a ceiling (not shown). The first conventional fluorescent lamp assembly includes a plurality of sets  10  of fluorescent lamps  100 , a plurality of control circuits  12  each connected to the power source (V 1 ) and a corresponding one of the sets  10  of the fluorescent lamps  100  in parallel, and a power switch  14  connected to the power source (V 1 ) and all of the control circuits  12 . When one of the fluorescent lamps  100  fails, the power source (V 1 ) must be shut down during replacement of the fluorescent lamp  100  to prevent any danger of electric shock. Since the power switch  14  is opened to provide an open circuit loop, the other fluorescent lamps  100  will not generate light, thereby resulting in inconvenience because replacement of damaged fluorescent lamps  100  is performed in dark. 
     FIGS. 2 and 3 illustrate a second conventional fluorescent lamp assembly  2  of the aforesaid type. The second conventional fluorescent lamp assembly  2  includes a power source  20 , a power switch  201 , sets  26  (only one is shown) of fluorescent lamps  261  and control circuits  27  (only one is shown). The second conventional fluorescent lamp assembly  2  further includes batteries  21 , and test switches  28  (only one is shown). Each of the batteries  21  is connected to a corresponding one of the control circuits  27  and a corresponding one of sets  26  of the fluorescent lamps  261 , and is disposed on a ceiling  22 . Each of the test switches  28  is connected to the power switch  201  and a corresponding one of the control circuits  27 . Each of the test switches  28  has a cord  23  extending downwardly. The batteries  21  can be tested to provide electrical power to the fluorescent lamps  26  by pulling the cords  23  with the use of a rod  25  having a hook portion  24  to open the test switches  28  and disconnect the power source  20  from the control circuits  27 . 
     The following are some of the drawbacks of the aforesaid conventional fluorescent lamp assemblies: 
     1. When exchanging a broken fluorescent lamp  261 , the power switches  14 ,  201  should be opened, thereby resulting in inconvenience due to the need to replace the lamps  100 ,  261  in the dark. In addition, the need to operate the power switches  14 ,  201 , which are normally disposed on a wall far from lamps  100 ,  261 , requires the operator to run back and forth between the lamps and the power switch during the lamp replacement operation. 
     2. When exchanging a worn battery, a part of the ceiling  22  should be detached for taking out the worn battery  21 . 
     3. When testing -the batteries  21 , the rod  25  should have the hook portion  24  for lugging the cords  23 , thereby resulting in inconvenient operation. 
     SUMMARY OF THE INVENTION 
     The main object of the present invention is to provide an easy-to-maintain fluorescent lamp assembly having a lamp switch that can control directly a corresponding set of fluorescent lamps. 
     According to this invention, a fluorescent lamp assembly is adapted for connection with a power source, and includes a plurality of sets of fluorescent lamps, a plurality of control units and a main power switch. 
     Each of the sets of fluorescent lamps has a lamp seat for holding the fluorescent lamps. 
     The control units are adapted to be connected to the power source and are mounted on the lamp seats, respectively. Each of the control units is connected to a corresponding one of the sets of the fluorescent lamps in parallel for activating the corresponding set of the fluorescent lamps, and has a lamp switch for controlling activation of the corresponding set of the fluorescent lamps. 
     The main power switch is connected to all of the control units and is adapted to be connected to the power source for controlling the power source to provide electrical power to all of the control units. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: 
     FIG. 1 is a circuit diagram of a conventional fluorescent lamp assembly; 
     FIG. 2 is a schematic partly sectional view of another conventional fluorescent lamp assembly when mounting on a ceiling; 
     FIG. 3 is a circuit diagram showing one of the sets of fluorescent lamps of the lamp assembly in FIG. 2; 
     FIG. 4 is a circuit diagram showing the first preferred embodiment of a fluorescent lamp assembly according to the present invention; 
     FIG. 5 is a schematic partly sectional view showing a lamp set of the first preferred embodiment when mounted on a ceiling; 
     FIG. 6 is a schematic partly sectional view showing a lamp set of the second preferred embodiment of a fluorescent lamp assembly according to the present invention when mounted on a ceiling; 
     FIG. 7 is another schematic partly sectional view of a lamp set of the second preferred embodiment; and 
     FIG. 8 is a circuit diagram showing one of the sets of fluorescent lamps of the second preferred embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 4 and 5, the first preferred embodiment of a fluorescent lamp assembly ( 3 ) according to the present invention is shown to be adapted for connection with a power source (V 2 ), and includes a plurality of sets (A, B, C, . . . ) of fluorescent lamps  36 , a plurality of control units  30  and a main power switch  32 . 
     Each of the sets (A, B, C, . . . ) of fluorescent lamps  36  has a lamp seat  37  mounted on a ceiling  38  for holding the fluorescent lamps  36 . 
     The control units  30  are adapted to be connected to the power source (V 2 ) and are mounted on the lamp seats  37 , respectively. Each of the control units  30  is connected to a corresponding one of the sets (A, B, C, . . . ) of the fluorescent lamps  36  in parallel for activating the corresponding set of the fluorescent lamps  36 , and has a lamp switch  34  for controlling activation of the corresponding set of the fluorescent lamps  36 . 
     The main power switch  32  is connected to all of the control units  30  and is adapted to be connected to the power source (V 2 ) for controlling the power source (V 2 ) to provide electrical power to all of the control units  30 . 
     The fluorescent lamp assembly  3  further includes a plurality of fuses  35 . Each of the fuses  35  is connected between a corresponding one of the sets (A, B, C, . . . ) of the fluorescent lamps  36  and the power source (V 2 ). 
     When one of the fluorescent lamps  36  in the set (A) breaks down, the lamp switch  34  can be opened to form an open circuit loop without operating the power switch  32  such that the broken fluorescent lamp  36  can be replaced safely and such that the other sets (B, C, . . . ) of the fluorescent lamps  36  can still generate light. 
     FIGS. 6 to  8  illustrate the second preferred embodiment of a fluorescent lamp assembly according to the present invention, which is based on the first preferred embodiment. In this embodiment, the fluorescent lamp assembly includes a plurality of sets  49  (only one is shown) of four fluorescent lamps  42  adapted to be connected to a power source  40  in parallel, a plurality of control units  41  (only one is shown), and a main power switch  44 . Each of the sets  49  has a lamp seat  46  for holding the fluorescent lamps  42 . 
     Each of the sets  49  of the fluorescent lamps  42  further includes two casings  47 , a battery unit having two batteries  43 , and a test switch  44 . Each of the casings  47  is mounted on the corresponding lamp seat  46 , which is mounted on a ceiling  5 . Each of the batteries  42  is disposed in a corresponding one of the casings  47 . Each of the battery units is connected to a corresponding one of the control units  41  to supply electrical power to the corresponding one of the control units  41  in a known manner when the power source  40  is shut down. Each of the lamp seats  46  has a top wall  461  with two apertures  462 . Each of the casings  47  is disposed above and is mounted on the top wall  461 , and opens at a respective aperture  462 . Each of the top walls  461  has two openable covers  48  to close the apertures  47 , respectively. The test switch  44  is connected to the main power switch  401  and the corresponding control unit  41  and is operable to control the corresponding control unit  41  to receive electrical power from the corresponding one of the battery units even though the power source  40  is not shut down. The test switch  44  is a push button switch which is disposed on the top wall  461  of the corresponding lamp seat  46 , as shown in FIG.  7 . The test switch  44  can be easily operated with the use of a rod  50 , as shown in FIG.  6 . 
     When one of the fluorescent lamps  42  breaks down, a corresponding lamp switch  45  can be opened to form an open circuit loop without operating the power switch  44  such that the broken fluorescent lamp  42  can be replaced safely and such that the other fluorescent lamps  42  can still generate light. Furthermore, the batteries  43  can be easily replaced by opening the covers  48 . The object of the invention is thus met. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.