Abstract:
A novel lantern lock for holding a light and its light shade in a fixed position when mounted on standard lighting equipment is presented. The lantern lock includes a socket assembly with a light bulb socket and power cord. A spreading frame is fixedly attached to the socket assembly, and when a shade is mounted thereon, holds the shade in a fixed position relative to the socket assembly. In one embodiment, the socket assembly is mounted on a base and mounting stud is physically attached to the socket assembly. In an alternative embodiment, a clamp clamps at least a portion of the socket assembly, and the mounting stud is attached to the clamp. The mounting stud is compatible with standard lighting equipment mounting devices, such as a C-clamp mountable on an extension arm of a C-stand. The C-clamp may be rotated in any position to fix the position of the mounting stud, and to thereby fix the position of the light.

Description:
This application claims the benefit of priority from U.S. Provisional Patent Application Ser. No. 60/463,941 filed Apr. 18, 2003. 

   BACKGROUND OF THE INVENTION 
   The present invention relates generally to film and video production lighting, and more particularly to a lantern lock for locking a hanging-style lamp into a fixed but controllable position. 
   Lamps are standard equipment in the film and video production industry. Different lighting is used for different purposes. Some productions require the use of diffused lighting. One way of achieving this effect is through the use of a lantern having an accordion-style shade (sometimes referred to as a “Chinese lantern”). As known by those in the lighting and film industries, an accordion-style shade lantern includes a shade having a material such as rice paper or cloth collapsibly attached to a plurality of ribs, which when fit over a lamp spreader, spread out to form an expanded lantern. The accordion-style lantern may take on various shapes, such as spherical or global, box-shaped, etc. The shape and configuration of the lantern shade ribs, will vary from design to design. For example, in a spherical accordion-style lantern shade, the ribs will typically be concentric wire rings that are connected together via material such as rice paper, ribbon, cloth, etc. The flexibility of the material allows the lantern shade to collapse into a fully collapsed position, (e.g., planar) and to expand to a fully expanded position (e.g., a sphere for a spherical accordion-style lantern shade, or a 3-dimensional box shape for a box-shaped accordion-style lantern shade). When used, the shade is mounted on a spreader frame which expands and retains the shade in its fully expanded position. A light bulb socket assembly with a power cord is attachable to the shade. Light emitted by the bulb is diffused by the shade and ideal lighting for certain types of filming. 
   One problem with the current design of such lanterns is the hanging assembly. The power cord that attaches to the socket assembly is designed to operate not only to power the lantern bulb, but also to attach to a ceiling hook to hang down from the ceiling. This design is problematic for the film and video industries for several reasons. First, it is oftentimes desirable to position the lantern in positions other than hanging from a fixed point of a ceiling. However, no means exist for positioning the lantern from below, from the side, or at any other angle. In addition, without additional stabilizing equipment, the lamp is susceptible to undesirable swinging due to its hanging configuration (for example, due to natural or artificial wind, or from people or objects unintentionally bumping into the lamp). Accordingly, a need exists for a technique for a locking a hanging-style lamp into a fixed but controllable position. It would be desirable if such technique included a means for interfacing the lock to standard lighting stands and equipment that are already and readily available. 
   SUMMARY OF THE INVENTION 
   The present invention is a novel lighting device for the film and video production industry. The invention is a lantern lock assembly that replaces or attaches to the socket assembly of a hanging-style lamp and which locks a lamp into a fixed position relative the lantern lock. The lantern lock assembly includes a clamping device that allows the lamp to be fixedly positioned relative the clamp. Accordingly, the lamp may be positioned in a variety of positions limited only by the number of clampable positions. 
   In the preferred embodiment, the lantern lock replaces the hanging socket assembly and spreading unit of a hanging lantern of the type having an accordion-style lamp shade. In this embodiment, the lantern lock includes a corded light bulb socket fixedly attached to an accordion-style lamp shade spreader. The lantern lock also includes a stud that is matable with a clamping device. In the preferred embodiment, the stud is ⅝″ and designed to be clamped and held by standard film and video production accessories which accept a ⅝″ or ¾″ stud, such as a Mathews “C stand” with griphead. 
   In operation, a light bulb such as a standard-base  24  bulb or a floodlight is screwed into the lantern lock socket and an accordion-style lamp shade is fit over the spreader and hooked into position. The lantern lock stud is inserted and locked into a clamping device. In the preferred embodiment, the clamping device is a C stand griphead mounted on a “C” stand. The C stand griphead is adjusted to position the lamp into the desired position with precision control. The lamp is powered by plugging the lantern lock power cord into a power source such as a standard outlet. 
   The lantern lock is advantageous for several reasons. First, because the lantern lock is clampable, a lamp originally designed for hanging on a cord is positionable in any desired position. In addition, because the lantern lock fixes the lamp relative to the lock, the lamp is prevented from swinging. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of this invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
       FIG. 1A  is a cross-sectional view of a preferred embodiment of a lantern lock implemented in accordance with the invention, illustrating the view from the x-z plane; 
       FIG. 1B  is a cross-sectional view of the lantern lock of  FIG. 1A , illustrating the view from the y-z plane; 
       FIG. 1C  is a cross-sectional view of the lantern lock of  FIGS. 1A and 1B , illustrating the view from the x-y plane when looking up from the bottom of the lantern lock; 
       FIG. 2  is a cross-sectional view of a preferred embodiment of a lantern lock implemented in accordance with the invention, illustrating the view from the x-z plane, with a bulb and shade mounted thereon; 
       FIG. 3A  is a cross-sectional view of an griphead used to fixedly position the lantern lock to a C-stand; 
       FIG. 3B  is a perspective view of the lantern lock of the invention clamped by the griphead of  FIG. 3A ; 
       FIG. 4A  is a perspective view of the lantern lock of the invention mounted on a C stand using a griphead and positioned at approximately 270°; 
       FIG. 4B  is a perspective view of the lantern lock of the invention mounted on a C stand using a griphead and positioned at approximately 90°; 
       FIG. 4C  is a perspective view of the lantern lock of the invention mounted on a C stand using a griphead and positioned at approximately 225°; 
       FIG. 4D  is a perspective view of the lantern lock of the invention mounted on a C stand using a griphead and positioned at approximately 135°; 
       FIG. 5A  is a cross-sectional view of an alternative embodiment of a lantern lock implemented in accordance with the invention, illustrating the view from the x-z plane, with the clamp assembly clamping the power cord assembly; 
       FIG. 5B  is a cross-sectional view of the lantern lock of  FIG. 5A , illustrating the view from the y-z plane; 
       FIG. 5C  is a cross-sectional view of the lantern lock of  FIGS. 5A and 5B , illustrating the view from the x-z plane, with a light shade mounted thereon; 
       FIG. 5D  is a cross-sectional view of the lantern lock of  FIGS. 5A and 5B , illustrating the view from the x-z plane, with the clamp assembly clamping the socket assembly; and 
       FIG. 5E  is a cross-sectional view of the lantern lock of  FIG. 5D , illustrating the view from the y-z plane. 
   

   DETAILED DESCRIPTION 
   Turning now to the drawings,  FIGS. 1A ,  1 B, and  1 C illustrate a preferred embodiment of a lantern lock  10  implemented in accordance with the invention, showing the view of the x-z plane, the y-z plane, and the x-y plane, respectively. As illustrated, the lantern lock  10  includes a mounting stud  12  attached to a socket assembly  20 . The socket assembly  20  includes a threaded light bulb socket  22  attached to a base  24  and a power cord  26  electrically attached to the socket  22 . In the preferred embodiment, the mounting stud  12  is a hollow cylindrical tube, and the power cord  26  is threaded through the tube, which is welded to the base  24 . 
   The lantern lock  10  also includes a spreading frame  30  fixedly attached to the mounting stud  12 . In the preferred embodiment, the shade  5  ( FIG. 2 ) to be mounted onto the spreading frame  30  is an accordion-style global shade having a material such as rice paper or cloth collapsibly attached to a plurality of concentric wire ring pairs. Accordingly, the spreading frame  30  is an accordion-style global shade spreader. The spreading frame  30  comprises two hooks  32   a ,  32   b  extending perpendicularly from the mounting stud  12 , two extension arms  34   a ,  34   b  and a hook arm  36  and a stabilizing rod  38 . In the preferred embodiment, the hooks  32   a ,  32   b  are attached via welding or screws to the bottom of the socket assembly base  24 . The two extension arms  34   a ,  34   b  are attached at their first ends symmetrically on and perpendicular to the hooks  32   a ,  32   b . The hook arm  36  is attached perpendicular to and across the second ends of the two extension arms  34   a ,  34   b . The stabilizing rod  38  is attached parallel to and on top of the hook arm  36 . The hook arm  36  includes two hooks  35   a ,  35   b.    
   In the preferred embodiment, the socket assembly  20  comprises a standard ceramic light socket  22  with a 14 Awg wire power cord  26 . The mounting stud  12  comprises a ⅝″ or ¾″ steel tube having 3/32″ walls. The spreading frame  30 , including the hooks  32   a ,  32   b  is made of 3/16″ mild steel wire. The global shade  5  is preferably a 11¾″, 17″, 22″, or other standard diameter sized accordion-style global lantern shade. 
     FIG. 2  illustrates the lantern lock  10  with a light bulb  4  inserted into the socket  22  such that it is electrically connected to the power cord  26  of the shade  5 .  FIG. 2  also illustrates a global style—style shade mounted onto the spreading frame  30  of the lantern lock  30 . As shown, the lantern lock  10  is inserted into a first open end of the shade  5 . The hooks  35   a ,  35   b  of the hook arm  36  engage the smallest concentrical ring  5   a  of the shade. As the lantern lock  10  is inserted into the shade  5 , the two extension arms  34   a ,  34   b  begin to push open the collapsed shade  5 . The lantern lock  10  is inserted inside the shade until the hooks  32   a ,  32   b  engage and springably slip over the opening concentric ring  5   b  of the shade  5 . At this point, the shade is fully open and securedly mounted over the spreading frame  30  of the lantern lock, as shown in  FIG. 2 . 
     FIG. 3A  is a top cross-sectional view, and  FIG. 3B  is a perspective view, of an example griphead  40  that may be used in the filming and lighting industry to attach a device to a C-stand  50  (see  FIGS. 4A–4D ). As illustrated in  FIG. 3A , the griphead  40  includes an arm clamp  42  attached to a C-clamp  44 . The arm clamp  42  includes an arm support  42   a  that includes a hollow tunnel  42   b  through which an extension arm  52  may be inserted, and a T-knob  41  that screws through the arm support  42   a  and into the tunnel  42   b  at an angle perpendicular to the axis of the tunnel  42   b . When an extension arm  52  is inserted into the hollow tunnel  42   b  of the arm support  42   a , the T-knob  41  may be turned in a first direction (e.g., clockwise) direction to tighten the screw so as to securedly attach the griphead  40  to the extension arm  52 , and may be turned in a second direction (e.g., counter-clockwise) direction to loosen the screw so as to be able to remove the extension arm  52  from the griphead  40 . 
   The C-clamp  44  includes a first block  44   a  attached to the arm clamp  42 , which has a groove formed therein in the cross-sectional shape of a half-circle, or “C”. The C-clamp  44  also includes a second block  44   a  which has a similar groove formed therein in the cross-sectional shape of a half-circle, or “C”. The blocks  44   a  and  44   b  are positionable such that the grooves  46   a ,  46   b  align to form a hollow substantially circular tube  48  through which a mounting stud  12  of appropriate diameter may be inserted into the tube  48 . The clamp blocks  44   a  and  44   b  may then be tightened, via a T-knob  45 , to form a secure grip around the mounting stud  12 . Alternatively, a locking pin mechanism may be used to fix the position of the mounting stud  12  within the tube  48 . Locking pin mechanisms are well known in the art. 
     FIG. 3B  illustrates the lantern lock  10  of the invention inserted into the C-clamp  44  of the griphead  40 . The angles of the extension arm  52  and the mounting stud  12  of the lantern lock  10  mounted in the C-clamp  44  are adjustable by loosening (or unscrewing) the respective T-knobs  41 ,  45 , adjusting the angle of the extension arm  52  and the mounting stud  12  of the lantern lock  10  to the desired relative angles, and then tightening (or screwing in) the respective T-knobs  41 ,  45  until the respective extension arm  52  and the mounting stud  12  are fixed in position. 
   In the preferred embodiment, the T-knob  45  of the griphead clamp  44  allows the clamp  44 , and therefore the lantern  10 , to be precision positioned substantially in any angular position along the plane of the extension grip arm  52 . In the preferred embodiment, the tube  48  of the griphead C-clamp  44  accepts a ⅝″ or ¾″ stud and a locking pin. 
     FIG. 4A  illustrates the lantern lock  10  precision positioned by a griphead  40  of an extension grip arm  52  mounted on a C stand  50  with the lantern  10  (and therefore shade  5 ) positioned at approximately 270° in a 360° circle, as illustrated (assuming 0° is the left horizontal). The mounting of the mounting stud  12  of the lantern lock  10  in the grip head  40  prevents movement of the lantern in any direction; thus, the lantern will not swing regardless of air currents or movement of objects around it. 
     FIG. 4B  illustrates the lantern lock  10  precision positioned by the griphead  40  of the extension grip arm  52  mounted on the C stand  50  with the lantern  10  (and therefore shade  5 ) positioned at approximately 90° in the 360° circle. 
     FIG. 4C  illustrates the lantern lock  10  precision positioned by the griphead  40  of the extension grip arm  52  mounted on the C stand  50  with the lantern  10  (and therefore shade  5 ) positioned at approximately 225° in the 360° circle. 
     FIG. 4D  illustrates the lantern lock  10  precision positioned by the griphead  40  of the extension grip arm  52  mounted on the C stand  50  with the lantern  10  (and therefore shade  5 ) positioned at approximately 135° in the 360° circle. 
   As will be appreciated by the above description of the invention, the lantern lock  10  is advantageous over the prior art by offering a full range of lantern positioning possibilities (limited only by the positioning limitations of the clamp) and ensures that the lantern is locked into the chosen fixed position. 
     FIGS. 5A–5E  illustrate an alternative embodiment of a lantern lock  100  implemented in accordance with the invention. As illustrated, in this embodiment, the lantern lock  100  comprises a frame  102  over which an accordian-style light shade  5  is spread and held, as illustrated in  FIG. 5C . The light shade is preferably an accordian-style light shade  5  comprising a plurality of ribs  5   c  supporting a flexible material  5   d  with desired light diffusion properties. The lantern lock  100  also includes a clamp mechanism  110  which clamps at least a portion of the original socket assembly  104  supplied with the hanging lantern. The clamp device  110  includes a first clamp base  110   a  having a mounting stud  12  mounted thereon, and a second clamp base. A tightening mechanism  112  such as a screw tightens the clamp bases  110   a  and  110   b  together. The clamp device  110  may be used to clamp the socket assembly  104  (as shown in  FIGS. 5D and 5E ) or the power cord  26  (as shown in  FIGS. 5A ,  5 B, and  5 C) such that the frame  102  is fixedly positioned relative to the clamp device  110 . The lantern lock  100 , via the fixed mounting stud  12 , then operates similarly to the embodiment shown in  FIGS. 1A ,  1 B,  1 C,  2 ,  3 A,  3 B,  4 A,  4 B,  4 C, and  4 D for interfacing with standard film and video production lighting equipment such as C stand gripheads. 
   Although this preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. For example, it should be understood that the construction material of the mounting stud  12  and shade spreader may be variously embodied such as with aluminum or other metals, hard plastic, wood, etc. In addition, the light socket  22  may embodied to accommodate various types of light bulbs and more than one light bulb, the shade may be of various shapes and/or have various frame configurations, and the shade attachment may be otherwise embodied to securely hold the shade in accordance with the particular shade design. In addition, the accordion-style lantern shade may be configured in any of a number of various shapes, such as spherical or global, box-shaped, etc., and the shape and configuration of the lantern shade ribs may therefore vary from design to design. Further, although the invention has been shown used with an accordion-style lantern shade, the lantern lock of the invention may be adapted to support other lamp shade types and configurations. It is also possible that other benefits or uses of the currently disclosed invention will become apparent over time.