Patent Publication Number: US-6981783-B2

Title: Burglar alarm light

Description:
FIELD OF THE INVENTION 
   The present invention relates to improve the traditional burglar alarm light for an inventive mechanical design of an adjustable lamp set displacement inside the lamp shell. It is easy and cost effective for the user to alter the light projection type for either converging or scattering result on one single lighting fixture. 
   BACKGROUND OF THE INVENTION 
   Projection light is a common security apparatus used in residences and high rise buildings. It is usually installed on the entrance and exit of people or vehicles. The projection light normally is turned off. When vehicles, people or moving objects approach the entrance or exit, the sensor in the projection light will actuate the circuits in the projection light to turn on the projection light. It can scare off intruders and provide illumination function. It is widely used in the security facilities. 
   However, conventional projection light generally is installed on a high location to secure the most desirable projection angle and scope. To install the projection light, users have to climb a ladder to a higher location to fasten the projection light, then descend to the floor to check whether the projecting scope is proper. If the projection scope and angle are not desirable, users have to climb up again to make adjustment or change the installation location and projection angle. The installation task is cumbersome. Moreover, when users want to change the installation of the projection light, as the conventional projection light has a fixed projection focus, the installation location or projection scope cannot be changed at will. A new set of projection light has to be purchased. It is inconvenient to install or replace, and not economical. 
   SUMMARY OF THE INVENTION 
   Therefore the primary object of the invention is to resolve the aforesaid disadvantages and to avoid the drawbacks of the prior art. The invention has an adjustment mechanism in the projection light to adjust the displacement of the lamp set thereby to alter light projection type (converging or scattering) emitted from a light source. 
   In order to achieve the foregoing object, the burglar alarm light of the invention includes a shell, a lamp set housed in the shell and a shade coupled on the front end of the shell. An adjustment mechanism is installed in the shell to adjust the location of the lamp set thereby to change light projection type (converging or scattering) emitted from a light source. 
   Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
       FIG. 1  is an exploded view of the invention. 
       FIG. 2  is a perspective view of the invention. 
       FIG. 3A  is a cross section taken on line  3 A— 3 A in  FIG. 2 . 
       FIG. 3B  is a sectional view of an operating condition according to  FIG. 3A . 
       FIG. 4  is a schematic view of another embodiment of the invention adopted for the head light of a car. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1 ,  2 ,  3 A and  3 B, the burglar alarm light of the invention includes a shell  1 , a lamp set  3  located in the shell  1 , and a shade  4  coupled on the front end of the shell  1 . The shell  1  further has an adjustment mechanism  2  located therein to adjust the displacement of the lamp set  3  thereby to alter light projection type (converging or scattering). 
   The shell  1  is to house the adjustment mechanism  2  and the lamp set  3 . The shade  4  is coupled on the front end of the shell  1 . 
   The adjustment mechanism  2  includes a seat  21 . The seat  21  has a bottom section  211  which has an aperture  2111  formed thereon. The bottom section  211  has two opposing ends extending upwards to form respectively a first extended section  212 . The first extended section  212  has an operation slot  213 , and a first lug  2121  on the periphery and a second lug  2122  extending inwards. The seat  21  further is coupled with a rotary member  22  (being a screw in the drawings). The rotary member  22  has screw threads  221  and a hole  222 . In addition, the rotary member  22  runs through the aperture  2111  on the bottom section  211  and is coupled with a first retaining member  23  (being a C-shaped clip ring in the drawings) to confine on the bottom section  211  of the seat  21 . The hole  222  is coupled with a second retaining member  27  (being a pin in the drawings). The rotary member  22  has one end coupling with a moving member  24 . The moving member  24  has a bottom  241  which has a hole  2411  to receive the rotary member  22 . The bottom  241  of the moving member  24  has two opposing ends extended upwards to form respectively a first arm  242 . Each first arm  242  has a guiding member  2421  movable in the operation slot  213  of the seat  21 . In addition, the first arm  242  has one end extended inwards to form a second arm  243 . The second arm  243  has an anchor hole  2431 . The rotary member  22  has other end to couple with an anchor member  25 . The anchor member  25  is wedged coupled with an adjusting member  26  which engages with the rotary member  22  in the shell  1 . The adjusting member  26  is turnable by users by a force, such as turned by user&#39;s fingers or having a hole on one end to engage with a hand tool or a coin for turning. 
   The lamp set  3  includes a socket  31 , a spacer  32  and a lamp bulb  33  mounted onto the socket  31 . The socket  31  is fastened to the anchor hole  2431  of the moving member  24  through a fastener (such as screw). The spacer  32  is an annular ring to allow the socket  31  and the lamp bulb  33  to pass through. The spacer  32  has two holes  321  to couple with the first lug  2121  of the seat  21 . The spacer  32  has heat insulation effect, and may guide the lamp bulb  33  when the lamp set  3  is moved. 
   The shade  4  has a reflective mirror  41  to converge light emitted from the lamp bulb  33  and project the reflected light to a desired location. 
   When in use, users turn the adjusting member  26 . As the adjusting member  26  is connected to the rotary member  22 , the rotary member  22  is driven and rotates. And the screw threads  221  of the rotary member  22  push the moving member  24  forwards or rearwards horizontally. As the moving member  24  is fastened to the socket  31  which in turn is coupled with the lamp bulb  33 , thus turning of the rotary member  22  will move the socket  31 , lamp bulb  33  and moving member  24  horizontally to achieve the object of adjusting the focal distance of light. 
   Referring to  FIGS. 3A and 3B , when users want to adjust the focal length closer, the rotary member  22  may be turned in one direction and moved rearwards, and move the lamp bulb  33  closer to the reflective mirror  41  of the shade  4  to achieve light converging effect. When the moving member  24  is moved closer to the bottom section  211  of the seat  21 , the first retaining member  23  is bucking against the moving member  24  to prohibit the moving member  24  form moving continuously. 
   On the other hand, when users want to adjust the focal distance of the light farther away, the rotary member  22  may be turned in reverse direction to move the lamp bulb  33  away from the reflective mirror  41  of the shade  4  at a longer distance to achieve light scattering effect. When the moving member  24  is moved away horizontally from the rotary member  22 , the second retaining member  27  is bucking against the bottom  241  of the moving member  24  to prohibit the moving member  24  from escaping the rotary member  22 . 
   Moreover, aside from manually adjusting the focal distance of the light, adjustment of the focal distance of the light may also be accomplished electrically so that the invention may be coupled with projection lights that have various actuators. Refer to  FIG. 4  for another embodiment of the invention adopted for use on a car light. As shown in the drawing, the invention is coupled with an actuator  5  on the head light of a car. The main difference from  FIG. 3A  is that the rotary member  22  is replaced by a worm  22 ′ which has one end connecting to the actuator  5 . The actuator  5  may be a motor, server motor, or the like. The actuator  5  may drive the worm  22 ′ to rotate, thereby drivers can adjust the projection focal distance of the head light as desired. 
   The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.