Abstract:
An adjustable light includes a knock down base frame, a vertical frame, which supports a boom arm, which in turn supports a light fixture. The light fixture is supported on the boom arm by a fixture mount that provides five degrees of freedom of movement of the light fixture relative to the boom arm. The boom arm is pivotally mounted to the vertically adjustable frame, thereby providing two additional degrees of freedom to the light fixture relative to the ground. The base frame includes two legs that are movably secured to the base frame. The base frame and the legs include wheels, the wheel supports being movably mounted to the frame and legs to allow for free movement on any planar surface on which the adjustable light is supported. The boom arm and the shield of the light fixture include bumpers to prevent damage by inadvertent contact to a surface. The lens in the fixture is replaceable to allow the user to use different lenses as dictated by the job requirements. A typical lens includes a substantially opaque section approximately one inch wide that is positioned in the center of the lens and runs the length of the lens.

Description:
FIELD OF THE INVENTION 
   The present invention generally relates to lighting devices. More specifically, the present invention relates to adjustable lighting devices used in a work environment. 
   BACKGROUND OF THE INVENTION 
   Shop lights are an integral part of industry from large-scale production to small shops. Proper vision is imperative to quality work. This is never more important than in the area of dent removal on automobile bodies. In some light a dent can be obvious, yet in other light not visible at all. What the technician needs to do is create a shadow by providing an angle of incident of the light rays to properly view the dent. The light is also used to guide the technician in the placement of the appropriate dent removal tool and guide him in the force application to remove the dent without causing additional damage to the vehicle&#39;s body or paint. Positioning the light fixture to obtain the proper angle of incident requires a stable but greatly adjustable light stand supporting the fixture. Fine adjustments need to be made with minimal effort in that the technician&#39;s eye must be primarily trained on the area of the dent, and not concentrating on the light stand. 
   The frame is preferably able to “knock down” to provide inexpensive shipping and storage capabilities. The frame must allow the light to adjust to a variety of positions and angles with several degrees of freedom including the overall height, angle and pitch of the light fixture. The lens is preferably interchangeable to allow different tints and blackout areas, which assist the technician in creating shadows. Finally the product is preferably lightweight, thus making it easy to maneuver and adjust. 
   SUMMARY OF THE INVENTION 
   In one aspect, the invention features a base frame with an adjustable height vertical frame, which is releaseably mounted to the base frame. A boom arm is pivotally mounted to an upper portion of the vertical frame and includes a clamp lock. This lock provides an infinitely adjustable position of locking of the boom arm on the vertical frame. A light fixture; is attached to a fixture mount that is slideably and rotateably mounted on the boom arm. 
   The base frame may include at least two legs that are movably mounted to the base frame. The base frame and the legs may include at least two wheels to facilitate transport of the device. The wheels are preferably movably (pivotally) mounted to the base frame and legs. The clamp lock is comprised of a pair of concave pressure plates, a threaded fastener and a cap handle. The boom arm includes an end disk positioned at one end thereof, the end disk being captured between a pair of ears on the vertical frame, the pair of concave pressure plates being positioned on the outside of, and adjacent to, the pair of ears. 
   The light includes a bumper strip mounted to a peripheral edge of a lamp shield and the boom arm includes a bumper pad positioned on a distal end thereof. The fixture mount supports the light fixture by a ball and socket joint and the mount preferably includes a split collar and a tension device, such as a threaded fastener, enabling adjustable tension on the ball of the ball and socket joint. The fixture mount includes a friction lock enabling the fixture mount to be releaseably positioned on the boom arm. 
   The light fixture includes a shield with a base angle between 20° and 30° relative to a lens and optimally 25° relative to the lens. The light fixture includes a lens with a substantially opaque area in the center thereof and runs the length of the lens. This substantially opaque area is between 0.75 inches and 1.25 inches wide and is preferably one inch wide. 
   In another aspect, the invention includes a method of using an adjustable light including the steps of providing a device as previously disclosed, adjusting the height of the vertical frame, adjusting the angle of the boom arm relative to said vertical frame, adjusting the position of the light fixture by movement of the fixture mount on the boom arm and positioning the light fixture on the fixture mount. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects of this invention, the various features thereof, as well as the invention itself, may be more fully understood from the following description, when read together with the accompanying drawings, described: 
       FIG. 1  is an isometric view of an adjustable light in a stored position, the light produced in accordance with the present invention. 
       FIG. 2  is an isometric view of an adjustable light in an extended position, the light produced in accordance with the present invention. 
       FIG. 3  is an isometric view of an adjustable light as it would be typically used and showing the degrees of freedom of movement of the light fixture and legs, the light produced in accordance with the present invention. 
       FIG. 4  is an isometric exploded view of light fixture and boom arm and part of the vertical frame and showing the assembly of the boom arm onto the vertical frame stem, the light produced in accordance with the present invention. 
       FIG. 5  is an isometric exploded view of truncated light fixture and fixture mount, the light produced in accordance with the present invention. 
       FIG. 6  is an isometric exploded view of a light fixture, the light produced in accordance with the present invention. 
       FIG. 7  is a side view of light fixture showing the angles of reflected light rays and opaque area, the light produced in accordance with the present invention. 
   

   For the most part, and as will be apparent when referring to the figures, when an item is used unchanged in more than one figure, it is identified by the same alphanumeric reference indicator in all figures. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The present invention is an adjustable light with specific applications to industry, in particular the area of automotive dent removal. Many of the advantages of this light are noted as advantageous to a variety of other applications such as light stands used in photography but the emphasis in this disclosure will be in the area of the light function as it relates to automotive dent removal. The critical advantage to the invention as disclosed is the adjustment capability of the light fixture by the capability of the framework. Referring to the drawings,  FIG. 1  shows an adjustable light  10  in a compact position. The key element of the device is the light fixture  12 . The detail of this fixture  12  will be disclosed later in the text, but a critical advantage of the light  10  is the capability to position the fixture  12  in a great variety of positions relative to the base  14 . 
   It is many times advantageous for a product to “knock down”. Here the base  14  is shown as being comprised of a base frame  16  and two legs  18 . The legs  18  are movably mounted through the base frame  16  to allow for adjustment of the positioning of the legs  18  as well as the removal of the legs  18  for shipping or storage. This disassembly or reduced size framework is part of the “knock down” feature. Mobility is provided to the device  10  by the addition of wheels  20  on the base frame  16  and legs  18 . These wheels  20  include a rotateably mounted wheel supports  22  that allow for movement, preferably 360° of rotation of the support  22  and associated wheel  20  relative to the frame  14 . The arrow  24  illustrates the rotation of the wheels  20  by the wheel supports  22 . Screw knobs  26  are comprised of a handle with a threaded end. The receiving portion (on the frame  16 ) has a threaded insert that receives the treaded end. The tip of the threaded end can be pressed against the leg  18  to infinitely adjust and hold by friction the leg  18  at any position relative to the base frame  16  within the physical parameters of each. 
   A vertical frame receiver  28  is received by the base frame  16  and secured by two additional screw knobs  30 . The base frame  16  includes a pair of vertical studs (not shown) that are mounted to the crossbars  32  of the base frame  16 . These studs are used as a support and a base to apply a load from the screw knobs  30  to lock the vertical frame receiver  28  onto the base  14 . The vertical frame stem  34  is received by the vertical frame receiver  28 , together comprising an adjustable height vertical frame  36 . The movement of the stem  34  relative to the receiver  28  and secured by the upper screw knob  38  provides vertical positioning of the fixture  12 . 
   Angular adjustment is provided by a boom arm  40  that is pivotally mounted to ears  42  the upper end of the vertical frame  36 , specifically on the frame stem  34 . The pivotal mounting includes a clamp lock  44 . The clamp lock  44  includes a pair of pressure plates  46  that are pressed together by a cap handle  48 . Located between the ears  42  is an end disk  50  mounted to an end of the boom arm  40 . The compression of the plates  46  of the clamp lock  44  on the ears  42 , on the end disk  50  of the boom arm  40  secures the boom arm  40  into any angular position of the boom arm  40  relative to the vertical frame  36 . The fixture  12  is movably secured to the boom arm  40  by a fixture mount  52 . The fixture mount  52  enables the fixture  12  to be positioned along the longitudinal length of the boom arm  40  as well as to rotate around the long axis of the boom arm  40 . This combination gives additional height and angular position adjustment to the fixture  12 . 
   As a contrast, the device  10  is shown in an extended position in FIG.  2 . The boom arm  40  is rotated up and out away from the base  14  and locked in place with the clamp lock  44 . The fixture  12  has been extended toward the end of the boom arm  40  by use of the fixture mount  52 . The frame stem  34  is extended toward the end of the vertical frame receiver  28  and secured in place by the upper screw knob  38 . With the vertical and horizontal displacement of the center of gravity of the device  12  relative to that shown in  FIG. 1 , the legs  18  have been extended out away from the base frame  16  to increase the stability of the device  10 . 
   The adjustment capabilities are shown in FIG.  3 . The fixture  12  is mounted to the fixture mount  52  by a ball and socket joint. This will be further described in greater detail later in the text. The ball and socket allows for a change in the tilt angle (along the long dimension) of the fixture  12  as depicted by the first arrow  54 , as well as the pitch angle (along the short dimension) of the fixture  12  as shown by the second arrow  56 . This joint also allows for movement about any axis perpendicular to the top of the fixture  12 . This is depicted by the third arrow  58 . The ball and socket joint on the top of the fixture  12 , as it couples with the fixture mount  52 , provides for three degrees of freedom of movement or adjustment of the fixture  12 . The fixture mount  52  as it articulates with the boom arm  40 , allows for linear adjustment along the long axis of the boom arm  40 , as shown by the fourth arrow  60 . By using a round or cylindrical structure for the boom of the boom arm  40 , the fixture mount  52  can also be made to rotate about the long axis of the boom arm  40 , as shown by the fifth arrow  62 . Both the angular orientation and the linear positioning are adjusted by unscrewing the fixture knob  64  adjusting the fixture to the position desired and then tightening the fixture knob  64 , providing sufficient friction between the tip of the knob  64  and the boom arm  40 . Thus, with this arrangement of the fixture mount  52  on the boom arm  40  and the fixture mount  52  to the fixture  12 , a total of five degrees of freedom are realized. The boom arm  40  is provided with angular adjustment that can be secured by way of the clamp lock  44 . A sixth arrow  66  illustrates this angular adjustment. The final adjustment of the fixture  12  position is shown by the seventh arrow  68 , which demonstrates the vertical height adjustment of the stem  34  in the frame receiver  28 , which is secured by the upper screw knob  38 . These additional two degrees of freedom are added to the five provided by the fixture mount  52  to yield a total of seven degrees of freedom of adjustment of the fixture  12 . 
   With reasonable component lengths a stand can be approximately four feet high in a stored state and extend to over nine feet high with three feet of horizontal displacement from the base. The fixture can also be positioned to face up, down, or to either side and rotated horizontally, vertically or anywhere in between. Any instability is taken care of by the adjustment of the legs  18  relative to the base frame  16 . The leg arrows  70  show this adjustment. 
   The detail of the clamp lock  44  is shown in FIG.  4 . The optimal desire of the clamp lock  44  is to provide enough friction between the end disk  50  and the ears  42  to prevent rotation of the boom arm  40 . The key elements are the concave pressure plates  46  and the cap handle  48  that work with a threaded fastener  72 . The fastener  72  acts as a pivot for the boom arm  40  by the center hole in the end disk  50 . The concave aspect of the pressure plates  46  enable the frictional force applied to the ears  42  and the end disk  50  to be concentrated further from the axis, therefore increasing the braking torque at any specific force. This advantage enables the user to easily tighten the cap handle  48  to engage the clamp lock  44  with minimal effort. 
   At the end of the boom arm  40  is a bumper pad  74  to help prevent damage to a contacted object if the clamp lock  44  was inadvertently disengaged. The bumper pad  74  is preferably a pliable material such as rubber. A “crutch tip” is a common item that can be used in this capacity. The second use of the bumper pad  74  is as a stop to limit the axial displacement of the fixture mount  52  on the boom arm  40 . 
   A detail of the fixture mount  52  is provided in  FIG. 5. A  ball  76  is mounted to the upper portion of the fixture  12 . This remains rigid to the fixture  12  and can be mounted by any means that is known in the art. The mount  52  also includes a hub  78  with a core that is adapted to receive the ball  76 . The material of the hub  78  is preferably plastic or some other durable material with good bearing properties. This is advantageous in that the slider  80 , which glides on the boom arm  40 , can be made of the same material as the hub. This would reduce production costs by eliminating the need for additional bearings. With a low friction material, the normal force of the hub on the ball  76  must be reasonably high to provide enough friction between the hub  78  and the ball  76  to enable movement of the fixture  12  relative to the hub  78  and yet not allow it to move under the weight of the fixture  12 . A fastener is used to solve the potential problems of assembly of press fit parts and reduced friction due to wear. A bolt  82  inserts through a hole in the hub  78  and is received by a nut  84 . A slit  86  is provided in both sides of the hub  78  to allow for expansion and contraction of the inside dimension of the hub  78 , which articulates with the ball  76 . This fastener can be tightened or loosened to adjust the friction of the hub  78  against the ball  76  for personal preference and to accommodate wear. 
   A partially exploded view of the fixture  12  is shown in FIG.  6 . The fixture  12  includes a bulb  88  such as a florescent or other electric bulb. The shield  90  extends to the side of the bulb  88  and includes a lip  92  on either side to support a lens  94 . The lens  94  may be clear or colored. For use in the dent removal process a tinted lens such as yellow or green is many times desirable. An opaque strip  96  is placed in the center of the lens  94 . This strip can be a variety of widths but is preferably between 0.75 to 1.25 inches wide and optimally one inch wide. The strip  96  runs the length of the lens  94  and is used to provide additional shadowing to allow better viewing of any dents. Finally a pair of bumper strips  98  is mounted to a peripheral edge of a lamp shield  90 . These bumper strips  98  are preferably a soft material similar to the bumper pad  74  earlier noted. The strips  98  can be pressed onto the lips  92  of the shield  90  and held in place by the friction of the materials. The purpose of the strips  98  is to act as a cushion in the event of accidental contact with an object, such as a car body, and to assist in holding the lens  94  in place in the fixture  12 . 
   The fixture  12  is shown in side view in FIG.  7 . The lens  94  is positioned within the border of the shield  90  and secured by the lips  92 . The strips  98  are not shown in this view, but would be received by the distal end of the lips  92 . The opaque strip  96  is exaggerated in its thickness for illustrative purposes. This strip  96  can be a single layer of paint or a layer of material of any thickness. In most cases a coat of paint will be the most cost effective and equally functional. 
   The reflected light rays  100  being emitted from the bulb  88  are also shown here. These rays  100  are reflected to create a fade effect from the opaque strip  96  located in the center of the lens  94 . This is provided by the base angle (α) of the shield  90  relative to the lens  94 . This angle (α) can vary and still provide a desirable effect. The inventor has experimentally determined an optimal range of (α) to be between 20° and 30°. Optimally the angle is 25°. This somewhat flattened acute angle provides a diffused effect as the reflected light rays  100  are most intense near the center of the lens, at the edge of the opaque strip  96 , and become less intense toward the outside edges  102 . This follows as consistent with the direct light from the bulb  88  (not reflected off the shield  90 ). The closer to the bulb the greater the concentration of the direct rays and therefore the greater the light intensity. Many light shields are commonly made in the form of a parabola with the bulb at the focal point. This creates a directed beam of light, such as in a headlamp. Here the goal is quite different in that the desire is to create a shadowing effect. As such, a diffused light is desirable.