Abstract:
A clamp device designed for use in the motion picture industry where there is a need for temporarily mounting and supporting various lighting and other hardware on or from available surfaces and fixtures without marring them. The clamp device basically includes a fixed jaw attached to one end of a threaded shaft and an adjustable jaw which is movably mounted on the threaded shaft. A threaded adjustment member is coupled to the adjustable jaw to control the position of the jaw along the threaded shaft. Both jaws are configured to accommodate a multiplicity of variously shaped surfaces and structural members on which they are designed to be mounted.

Description:
RELATED APPLICATION  
       [0001]    This application claims priority from Provisional Application No. 60/340,441, filed Dec. 13, 2001. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention generally relates to clamping devices and, more particularly, to such devices which are specifically designed for use in the movie industry as supports for lighting and rigging equipment.  
           [0003]    One particular clamping mount of the type disclosed herein is the subject of U.S. Pat. No. 5,276,949, issued Jan. 11, 1994 to Steven L. Cordellini. The Cordellini clamp has become more or less standard in the motion picture lighting industry. Broadly considered, it comprises a pair of jaws and a partially threaded shaft. One of the jaws is fixed in position midway along the shaft adjacent the threaded portion. The other jaw is slidable along the threaded portion and is driven toward the fixed jaw to clamp the device on a support of some sort by a knob which has internal threads that made with the threaded portion of the shaft.  
           [0004]    To mount a light or piece of rigging hardware on the clamp device, it is affixed to the end of the shaft remote from the threaded portion. This end is shaped with a standard configuration for insertion into mounting receptacles that are standard on whatever items of equipment are to be mounted on the clamp device. Thus, when the knob is turned to tighten the two jaws of the device to grip a support member, the piece of lighting or rigging equipment which is attached to the unthreaded end of the shaft is supported as desired.  
           [0005]    While closing the jaws by rotating the knob serves to clamp the device in position, rotating the knob in the opposition direction does not always result in the device unclamping itself. Due to slight distortion of the slidable jaw resulting from the force used to clamp the jaws on a support element, the slidable jaw often remains locked in position when the knob is loosened. This is a common occurrence and it generally requires a tap from a hammer or the like to release the slidable jaw to an unclamped position.  
           [0006]    A number of items in the catalog of Matthews Studio Equipment, Inc. are listed and described in the introduction of the Cordellini patent. The reader is referred to the Matthews catalog and to the Cordellini patent for a description of the various items A through R from the catalog. Cordellini points out numerous deficiencies of the various items A through R and asserts the benefits of the Cordellini clamp over all of the prior art devices. The clamping device of the present invention is a significant advance in the art over the Cordellini clamp and it is expected to supersede the Cordellini clamp because of its numerous benefits, improvements and advantages with respect thereto.  
         SUMMARY OF THE INVENTION  
         [0007]    In brief, arrangements in accordance with the present invention comprise a pair of particularly configured jaws mounted on a threaded shaft with an internally threaded knob for adjusting the spacing between the jaws, both in closing the jaws to establish the clamping function about some support member, such as a pole, and in driving them apart to actively release the clamp. In addition, the invention can be used as a “wall spreader” by propelling the jaws apart in order to establish a mounting on a pair of opposed parallel surfaces, such as the sides of a door frame.  
           [0008]    The threaded shaft is threaded throughout its length with a No. 8 Acme thread. Thus, for economy of fabrication, it can simply be cut from longer threaded rod stock and does not require the special threading operation which is necessary in fabricating the device disclosed in Cordellini. The free end of the shaft has an internally threaded bore for receiving a threaded mounting pin to establish the configuration shown in the patent where the end of the shaft is formed in the configuration of a mounting pin. In addition, each of the jaws is provided with a plurality of threaded holes to receive a threaded mounting pin at different points on the jaws and at different angles.  
           [0009]    For ease of fabrication, the two jaws are formed in identical fashion to provide a variety of different surfaces which are particularly adapted to clamp onto support members of different shapes and sizes, for example, round poles or pipes, square or rectangular supports, large or small circular members and the like. The jaws are formed with clamping surfaces of different types, capable of clamping onto a wide variety of surfaces, at opposite ends of the jaws. Moreover, each of the jaws has its opposite faces shaped in complementary fashion to provide a V-shaped clamp groove in each face for permitting the jaws to clamp in either direction. The limits of the mounting surfaces (V-grooves and the like) on opposite faces of a given jaw device terminate at a plane for that face of the jaw, thereby serving to stabilize the clamp when it is mounted on any support member. In addition, each end of the jaw is provided with an opening of a size and shape to accommodate a carabiner for attaching a line, such as a cable, cord, rope or the like. If no carabiner is available, these opening accommodate the rope itself which may be passed through the opening and secured.  
           [0010]    The fixed jaw is provided with a circular recess extending about the threaded shaft. This is to accommodate a projecting titanium sleeve which is installed in the adjustable jaw, thus permitting the two jaws to be closed together if desired without interference by the protruding sleeve. This titanium sleeve protects the material of the aluminum jaw from wear or binding against the threads of the shaft.  
           [0011]    The adjustable jaw is provided with a U-shaped slot extending inwardly from one side of the jaw adjacent the titanium sleeve to receive a partially threaded brass sleeve during assembly of the adjustable jaw on the shaft. A ¾ inch deep knob with an ergonomically designed three-bladed handle and a hexagonal one-inch nut, directly below the handle, all constituting one piece, is fixedly mounted at one end of the brass sleeve. The hexagonal nut is provided with six flats to accommodate a wrench which may be used to apply more torque than could be developed by manually turning the knob. At the end of the brass sleeve remote from the knob is a head portion extending radially outward from and surrounding the sleeve. A washer is affixed to the face of the head portion which is nearer the hexagonal nut and is immovable by design.  
           [0012]    In assembling the adjustable jaw and the brass sleeve and knob on the threaded shaft, the head portion is slid laterally into the U-shaped slot of the jaw, together with another washer on the side opposite the first-mentioned washer, and the assembly is then threaded onto the threaded shaft.  
           [0013]    The pins which are provided with the clamps of the present invention are of ⅝ inch diameter, which is standard in the industry. However, each pin is provided with two flats at its distal end for engagement by a wrench. The pins are of two different lengths, each having a threaded end ⅜ inch in diameter. The threaded end is out from ⅜ inch rod, No. 16 thread, which is mounted in a threaded bore in the end of the pin and held with a stainless steel roll pin.  
           [0014]    A non-skid material is applied on all jaw faces. This can be developed by using a boat deck coating which is available from marine supply stores. This material serves to keep the metal, of the jaws from scratching items to which the clamp may be attached.  
           [0015]    Other features and advantages of the invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    The accompanying drawings illustrate the invention. In such drawings:  
         [0017]    [0017]FIG. 1 is an exploded orthogonal view, showing a clamp assembly in accordance with an embodiment of the invention with closed jaws;  
         [0018]    [0018]FIG. 2 is an orthogonal view of the adjustable jaw of the arrangement of FIG. 1 shown with jaws open;  
         [0019]    [0019]FIG. 3 is a bottom plan view of the adjustable jaw and adjusting knob assembly taken along line  3 - 3  of FIG. 2;  
         [0020]    [0020]FIG. 4 is an enlarged fragmented view of the area indicated by the line  4  in FIG. 3;  
         [0021]    [0021]FIG. 5 is a bottom view of the adjustable jaw and adjustable knob assembly taken along line  5 - 5  of FIG. 1;  
         [0022]    [0022]FIG. 6 is a bottom view of the adjustable jaw and adjustable knob assembly, taken along line  6 - 6  of FIG. 1, shown with mounting pins aligned for connection;  
         [0023]    [0023]FIG. 7 is an enlarged fragmented view of the area indicated by the line  7  in FIG. 6;  
         [0024]    [0024]FIG. 8 is a view of the adjustable jaw and adjustable knob assembly of FIG. 6 shown with the pins connected;  
         [0025]    [0025]FIG. 9 is a view of a pin assembly of FIG. 1, taken along line  9 - 9 , illustrating a pin, prior to connection to the clamp assembly;  
         [0026]    [0026]FIG. 10 is a view of the pin assembly of FIG. 2, taken along line  10 - 10 , illustrating a pin after connection to the clamp assembly;  
         [0027]    [0027]FIG. 11 is a view of the fixed jaw, taken along line  11 - 11  of FIG. 1, illustrating the circular recess extending about the threaded shaft to accommodate the projecting sleeve of the adjustable jaw;  
         [0028]    [0028]FIG. 12 is an exploded orthogonal view of the clamp assembly of FIG. 2, showing pins aligned for connection to the clamp assembly;  
         [0029]    [0029]FIG. 13 is an orthogonal view of the clamp assembly of FIG. 12, showing pins connected to the clamp assembly;  
         [0030]    [0030]FIG. 14 is a top plan view, showing a clamp assembly, in accordance with another embodiment of the invention, being used as a wall spreader;  
         [0031]    [0031]FIG. 15 is a cross-sectional view of an adapter element; and  
         [0032]    [0032]FIG. 16 is a cross-sectional view of another adapter element. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0033]    Structural details of the preferred embodiment of the clamping device of the invention are shown in FIGS.  1 - 5 . FIG. 1 represents the complete clamping apparatus  10  principally comprising an adjustable jaw assembly  12 , a fixed jaw  14 , and a threaded shaft  16 . The shaft  16  is threaded throughout its length and is preferably, for reasons of economy and ease of fabrication, cut to the desired length from a rod of threaded stock. As shown in FIG. 1, the shaft  16  includes a central or longitudinal axis  17 , a lower end  22 , an upper end  24 , and a midportion  26 . The jaw  14  is provided with a central bore which is threaded to receive the shaft  16 . After the jaw  14  and shaft end  22  are threaded together, the jaw  14  is fixed in position by the insertion of a pair of stainless steel roll pins  18  into holes in the shaft  16 . The shaft  16  is threaded with a number  8  Acme thread, which is the type of thread commonly used in small bench vises, to accommodate ready movement of the adjustable jaw along the length of the shaft  16 .  
         [0034]    The jaw  14  is provided with a total of five threaded bores or holes  14 A,  14 B,  14 C and  14 D. Hole  14 C extends completely through the jaw  14  in order to accept mounting pins  20  on the opposite side (thus providing the fifth threaded hole), such the pins  20  shown in FIGS.  1 - 8  and  10 - 11  which are provided to mate with mounting receptacles that are standard on an apparatus to be supported by the clamp  10 . These holes  14 A- 14 D make it possible to insert pins in at least five separate locations on the fixed jaw  14 . The holes may be vertically aligned with the central axis  17  but in different horizontal planes from the central axis  17  or each other (e.g., holes  14 B,  14 D as seen in FIG. 6). The holes may also be parallel to the central axis  17  though in a different horizontal plane (e.g., holes  14 B,  14 D as seen in FIG. 6). Additionally, the holes may be in a separate horizontal plane but perpendicular to the central axis  17  (e.g., holes  14 C,  29 B as seen in FIG. 6), or the holes may be at angle ranging between 0 and 60 degrees relative to the central axis  17  (e.g.,  14 A,  29 A as seen in FIG. 6).  
         [0035]    The adjustable jaw assembly  12  comprises a jaw  28  and an adjustment member  30 . Jaw  28  is provided with a threaded bore or hole  29 A for receiving a threaded mounting pin. Hole  29 A which may be at an angle ranging between 0 and 60 degrees relative to the central axis  17 . Hole  29 B extends completely through the jaw  28  in order to accept a mounting pin  20  on both sides of the jaw (providing three mounting holes on the jaw  28 ).  
         [0036]    The adjustment member  30  comprises a knob  32 , a hexagonal nut  34  and a hollow, partially threaded sleeve  36 . Sleeve  36  may be made of brass. The knob  32  and hexagonal nut  34  are fixed in position on the outside of the sleeve  36  to rotate the sleeve in locating the jaw  28  along the shaft  16 . The hexagonal nut  34  also serves as a spacer, providing more separation between the knob  32  and the near face of the jaw  28  so that the user can manipulate the adjustment member  30  more readily. The sleeve  36  is coupled to the jaw  28  so that as the threaded sleeve  36  is rotated to move along the shaft  16 , the jaw  28  is propelled along the shaft  16 , either toward or away from the fixed jaw  14 , depending on whether the knob  32  of the adjustment member  30  is rotated clockwise or counterclockwise. In addition, because the hollow bore of the jaw assembly  12  permits the rotation of the handle over the existing pin, one can achieve a total jaw opening of 3½ inches.  
         [0037]    As shown in FIGS.  1 - 10 , the knob  32  has a central hole or bore  37  for receiving the sleeve  36  and three ears or wings  38  to facilitate rotation of the adjustment member  30 . The nut or spacer  34  is provided with a plurality of flats  39  in a hexagonal configuration to permit use of a standard 8″ crescent-type adjustable wrench for tightening or loosening the adjustment member with greater force than can be developed manually with the user gripping the knob  32 . The knob  32  may be a ¾ inch deep knob with an ergonomically designed three-bladed handle. The nut  34  may be a hexagonal one-inch nut. The knob  32  and nut  34  may constitute a single piece and be fixedly mounted at one end of the brass sleeve  36 . The hexagonal nut  34  is provided with six flats to accommodate a wrench which may be used to apply more torque than could be developed by manually turning the knob.  
         [0038]    The adjustable jaw  28  is provided with a projecting sleeve  40  which extends throughout the central opening in the jaw  28  and projects from the side of the adjustable jaw  28  facing the fixed jaw  14 , as shown in FIGS. 3, 6, and  8 . The projecting sleeve  40  may be made of titanium as well as other similar materials or alloys. A circular mating recess  42  is provided in the fixed jaw  14  to receive the projecting end of the titanium sleeve  40 , thereby permitting the adjustable jaw  28  to be moved all the way into contact with the jaw  14  without interference by the projecting portion of the sleeve  40 . The circular recess  42  extends about the shaft  16 . This projecting titanium sleeve  40  protects the material of the jaw  14  from wear or binding against the threads of the shaft  16 . The jaws  14 ,  28  may be made of aluminum, steel, titanium, or any alloy the aforementioned materials.  
         [0039]    The upper end  24  of the shaft  16  is provided with a threaded bore  44  for receiving a threaded extension  46  of the pin  20 . The threaded bore  44  in the end of the shaft  16  is of the same size as the threaded bores  14 A- 14 D in the fixed jaw  14  and threaded bores  29 A,  29 B in the adjustable jaw  28  so that the same mounting pins may be used at each of the eight holes on the jaws  14 ,  28  as well as at the upper end  24  of the shaft  16  providing for a total of nine possible mounting points for the pin  20 . The threaded extension  46  of the pin  20  is out from ⅜ inch rod, No. 16 thread. The pin  20  is provided with a threaded bore  48  which receives a section  50  of a standard ⅜ inch threaded rod in a position fixed by a stainless steel roll pin  52 . The pin  20  is provided with a pair of opposed flats at its distal end  54  so as to accommodate a wrench for tightening or loosening pin  20  in end  24  of the shaft  16 . The pins  20  which may be used in conjunction with the clamp assembly  10  of the present invention may be ⅝ inch diameter, which is standard in the industry. The pins  20  may be of different lengths but the threaded extension  46  of each pin  20  is ⅜ inch in diameter.  
         [0040]    At the end of the sleeve  36 , remote from the knob  32 , is a radially outwardly extending, circumferential head portion  56  surrounding the sleeve  36 . The circumferential head portion  56  is slid into a slot  58  in jaw  28  during assembly of the jaw assembly  12 . The slot  58  may be U-shaped, extending inwardly from one side of the jaw  28  adjacent the titanium sleeve  40  to receive the partially threaded brass sleeve  36  during assembly of the adjustable jaw  28  on the shaft  16 . A first face of the radially extending portion  56  is provided with a first washer  60 , permanently affixed thereto. Prior to placement of the jaw assembly  12  onto the shaft  16 , the extending portion  56  is slid laterally into the slot  58  of the jaw  28  a second washer  62  is slipped into position along a second face of the radially extending portion  56 . Both washers  60  and  61  facilitate the spacing and lubrication of the radially extending portion  56  within the slot  58 . Removal of the upper jaw  28  from the threaded shaft  16  involves performing the same process in reverse order.  
         [0041]    In assembling the adjustable jaw  28 , brass sleeve  36 , and knob  32  on the shaft  16 , the adjustable jaw assembly  12  is placed over the upper end  24  of the shaft  16  and the adjustment member  30  is rotated to thread the assembly  12  onto and along the shaft  16 .  
         [0042]    Turning the knob  32  in one direction causes the adjustable jaw assembly  12  to apply a force to close the jaws  14 ,  28 . Turning the knob  32  in the opposite direction causes the adjustable jaw assembly  12  to apply a force in the opposite direction by virtue of the extended shaft portion  56  bearing against the ears  62  which extend inwardly into the opening above the slot  58 . The ears  62  form a reentrant portion partially enclosing the slot  58 .  
         [0043]    As seen in FIGS.  1 - 8  and  12 - 14 , the jaws  14 ,  28  have different sections which are variably shaped to accommodate the surfaces and shapes of various structural members on which a clamp device is supported. One of these features involves the “hourglass”-like shape of the jaws as  14 ,  28 . It will be understood that both jaws  14 ,  28  are essentially identical with respect to the structural shapes now being discussed. This shape involves the indentations  64  in the sides of the jaws  14 ,  28 . Also, the beveled edges  66  are provided at the corners of the jaw. This configuration serves to remove material at these points, thereby making the jaws lighter and also able to be inserted fore readily into certain limited access spaces for mounting the clamp.  
         [0044]    The opposed faces of each jaw include segments of planar surfaces. Thus, for example, the jaw  28  of FIG. 1 has segments  68 ,  70  along its upper face in which the flat, horizontal portions fall in the same plane. Similarly, the portions  72 ,  74  along the lower face of the jaw  28  lie in the same plane, as does the edge  76 . These planar elements are spatially distributed along the jaw so as to provide enhanced stability when the clamp is mounted against a planar surface. The intersecting planar surfaces  78 ,  80  of the jaw  28  (forming a v-shape), and their counterparts in the fixed jaw  14 , enable the clamp to be supported on a variety of structural configurations, particularly round tubing or columns of varying diameters. The same is true with respect to the intersecting planar surfaces  82 ,  84  (forming a v-shape), as well as their counterparts in the fixed jaw  14 , on the side of the jaw  28 .  
         [0045]    At the opposite end of the jaw  28  is an offset planar portion  86  having a V-shaped slot  88  extending transversely between the two planar portions  86 . A similar slot  90  is provided along the underside of the jaw  28 . These V-shaped slots  88 ,  90 , and their counterparts in the fixed jaw  14 , enable the clamp to be mounted on square stock supporting structures and prevent rotation of the stock in the clamp once the clamp is secured in either the clamping or spread mode. Curved portions  92  on opposite sides of the slot  90  facilitate clamping of the device on relatively large diameter cylindrical support elements (counterpart curved portions are also found in the fixed jaw  14  on opposite sides of the fixed jaw  14  counterpart to slot  90 ).  
         [0046]    In addition, the adjustable jaw  28  and fixed jaw  14  can be rotated 180° so that the flat end of one jaw is affixed to a square stock while the round end of the other jaw is affixed to a round stock. For example, this configuration works best when the invention is used to clamp onto a “D”-shaped object.  
         [0047]    In addition to the apertures  14 A- 14 D,  29 , each of the jaws is provided at each end with an opening or hole  94  for the attachment of a tether element, such as a carabiner or the like. If the attaching member does not include such an element at the end of the thether, for clipping into the opening  94 , a line, such as a cable, cord, rope or the like, can be fed through the opening and tied to the jaw.  
         [0048]    FIGS.  14 - 16 , illustrate a particular kind of adapter arrangement which extends the versatility of the clamping device of the invention in wall spreader mode. The adapter portion  96  comprise adapter elements  98 ,  100  (which may be identical) at opposite ends of a hollow cylindrical pipe  102 . The adapters  98 ,  100  are configured so that they may be inserted into the pipe  102  at opposite ends of the pipe  102 . The respective end portions  104 ,  106  of the adapters  98 ,  100  are of greater diameter than the portion of the adapter inserted within the hollow center of the pipe  102 . The outer diameter of the end portions of the adapters  98 ,  100  is less than the inner diameter of the hollow pipe  102  so that the adapters  98 ,  100  partially fit within the pipe  102 . The outer diameter of the respective end portions  104 ,  106  of the adapters  98 ,  100  need only be sufficiently greater than the inner diameter of the pipe  102  so that the end portions  104 ,  106  bear against their respective ends walls  103  of the pipe  102  so as to provide a compressive type of support. Each of the adapters  98 ,  100  has a central opening  108  or  110  of a dimension to accommodate a pin  20  of an adjacent clamping device  10 .  
         [0049]    The way in which these various components are assembled in use is illustrated in FIG. 14 where the combination is represented as being mounted between the opposite sides of a doorframe, for example. The sides of the frame are designated by the numerals  112 ,  114 . The pipe  102  with adapters  98 ,  100  is shown between a clamp device  10  and an angled foot  116  at opposite ends. The angled foot  116  may be at any relatively flat angle. In FIG. 14, the angled foot  116  is illustrated as approximately 3 degrees. In the alternative, the surface of an adapter contacting the angled surface of the angled foot  116  may itself be angled to match the angle of the foot  116 . For example, if the angled surface of the foot is 3 degrees, the angled surface of the adapter would be −3 degrees. The clamp  10  and the angled foot  116  bear against the door frame surfaces  112 ,  114  at opposite ends by turning the knob  30  counterclockwise, thus driving the adjustable jaw  28  away from the fixed jaw  14 , creating force against the frames  112 ,  114 . The surface of the adapter  100  in contact with the angled foot  116  could be covered with a non-slip coating to prevent slipping along the adapter/foot interface.  
         [0050]    The selected metal components of the invention make it possible to employ the invention under fresh or saltwater. The clamp device is designed so that no aluminum touches any stainless steel parts. Instead, the stainless steel parts are only in contact with brass or titanium parts. This metallurgical design also avoids bonding of the components b the electrolytic process.  
         [0051]    It will be appreciated that the clamping device of the present invention adds a novel and enhanced versatility to devices in the field of the invention, providing a clamp device which has a variety of uses. The clamp has an adjusting knob which couples to the adjustable jaw in a structural configuration which applies force to the adjustable jaw to drive it in either direction along the threaded shaft. This precludes the jaw jamming in a clamped position. Mounting pins for mounting the objects on a movie set are provided as separate items which are readily threadably attachable at numerous points on the jaws and at the free end of the shaft. Since these are separate items and since the threaded shaft is cut from threaded stock rod, the cost and difficulty of fabricating an integral pin and shaft are avoided. The above-described embodiments of the present invention are illustrative only and not limiting. It will thus be apparent to those skilled in the art that various changes and modifications may be made without departing from this invention in its broader aspects. Therefore, the appended claims encompass all such changes and modifications as falling within the true spirit and scope of this invention.