Abstract:
A multi-jaw clamp capable of attaching to various sized cylindrical objects such as iris rods of a professional movie camera. The multi-jaw clamp includes two housings that each hold a cylinder with at least two circular sections in the sides of the cylinders that are rotatable to change the size of the circular opening for the circular object to which the clamp can attach. The two housings contain hinge means for opening and closing the clamp and at each free end of the housings is a means for closing the clamp and locking the clamp in position around the cylindrical object.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The field of the present invention relates to a clamp for attaching a device to a cylindrical object. In particular, the invention relates to a clamp for attaching a filter and matte box assembly to the iris rods of a motion picture or video camera.  
           [0002]    As set forth in U.S. Pat. No. 5,349,411, it is conventional for a filter and matte box assembly to be provided with a clamping mechanism built into the assembly. This clamping mechanism is sized to fit a specific size of iris rod, which projects from the front of the camera. The filter and matte box assemblies have been made to fit different sized iris rods so that when one assembly is used with a particular sized iris rod clamp and then a new camera is used having a different iris rod size, a new filter and matte box assembly was required because of the clamp no longer fitting the iris rod on the new camera. In the alternative, the clamp on the assembly may be replaceable, which requires a selection of clamps.  
           [0003]    Since different camera manufacturers use different sized iris rods on their cameras, switching the entire filter and matte box assembly or the clamps to fit the different iris rods when changing cameras is an undesirable step. Also, this requires a camera rental company to maintain a large inventory of different sizes of clamps. Thus, it has been desirable to have a filter and matte box assembly that has a clamp that can fit varying sizes of iris rods to avoid having to replace the entire filter and matte box assembly. Having a clamp that can fit varying sizes of iris rods is also desirable because it is less expensive than having a number of filter and matte box assemblies or clamps. Therefore, a filter and matte box assembly that is capable of clamping to iris rods of several different sizes would be more economical and efficient and would reduce the number of matte box assemblies required.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention provides an improved clamp for attaching objects to cylindrical objects of varying diameters. The multi-jaw clamp of the present invention includes two housings connected by a hinge for holding a pair of multi-jaw cylinders. The multi jaw cylinders contain at least two curved sections to attach around at least two different diameters of cylindrical objects, such as iris rods. The multi-jaw cylinders can be rotated to fit different diameters of cylindrical objects. The housing is locked into place around the cylindrical object by a locking mechanism attached at the free ends of the housings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]    [0005]FIG. 1 is a top plan view of the multi-jaw clamp according to the present invention and diagrammatically illustrating the camera with the iris rods and the matte box assembly;  
         [0006]    [0006]FIG. 2 is a front elevation view of the multi-jaw clamp with the matte box assembly mounted on the clamp;  
         [0007]    [0007]FIG. 3 is an isometric view of the back of the clamp with the clamp in the open position;  
         [0008]    [0008]FIG. 4 is an isometric view of the front of the clamp with the clamp in the open position;  
         [0009]    [0009]FIG. 5 is an isometric view of the multi-jaw cylinder;  
         [0010]    [0010]FIG. 6 is a front elevation view of the clamp in the closed position;  
         [0011]    [0011]FIG. 7 is a top plan view of the clamp in the closed position;  
         [0012]    FIGS.  8 A- 8 C are plan views of the multi-jaw cylinders juxtaposed in three different positions for fitting three different sizes of iris rods;  
         [0013]    [0013]FIG. 9 is a cross-sectional view taken along the line  9 - 9  in FIG. 7 and showing the clamp in the closed position around a rod; and  
         [0014]    [0014]FIG. 10 is a cross-sectional view taken along the line  10 - 10  in FIG. 9 and showing the clamp in the closed position around a rod. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    The preferred embodiment of the present invention will now be described with reference to the drawings. To facilitate the description, a reference numeral representing an element in one figure will represent the same element in any other figure.  
         [0016]    [0016]FIG. 1 is a top plan view of the multi-jaw clamp  10  according to a preferred embodiment mounted to a camera  12  on an iris rod  14  projecting forwardly of the camera  12  with a matte box assembly  16  attached to the clamp. Of course, a camera may be provided with two iris rods and such case there will be two clamps  10 . The multi jaw clamp  10  includes a threaded hole  18  (best viewed in FIG. 9) for mounting the matte box assembly to the clamp so that the matte box is positioned in front of the camera lens  20 . The multi-jaw clamp  10  includes a hinge assembly  22  that permits the clamp to open and close around the iris rod  14  as viewed in FIG. 2.  
         [0017]    Details of the multi-jaw clamp are set forth in FIGS.  3 - 10 . The clamp  10  is provided with two housings  30  and  32  that are connected by the hinge assembly  22 , which allows the housings to open and close around the iris rod  14 . The hinge assembly  22  includes the hinge section  34  of housing  30  and the hinge section  36  of housing  32 , each of which hinge sections have holes through them to accommodate the hinge pin  38  extending the length of the hinge assembly  22 . The ends of each of the hinge sections  34  and  36  are curved to accommodate the opening and closing of the clamp. Any mechanism similar to a hinge that will allow relative movement of housings  30  and  32  in the unlatched condition, as described below, but prevents separation in the latched condition may be used in place of hinge assembly  22 .  
         [0018]    The housing  30 , as shown in FIG. 3, is generally rectangularly shaped and has a semi-circular channel  40  cut into the long side of the housing and runs the length of the short side of the housing. The housing  30  also contains a cylindrical hole  42  (best viewed in FIGS. 6 and 10) in the housing on the side opposite the hinge section  34  and cuts through the semi-circular channel  40 . The cylindrical hole  42  does not penetrate through the side of the housing adjacent to the hinge section  34 . The cylindrical hole  42  is sized to receive the multi-jaw cylinder  50  (best viewed in FIG. 10). The housing  30  also contains a rectangular shaped protrusion  52  on the side opposed to the semicircular channel  40  that contains a threaded hole  18  (shown in FIG. 9) for attaching a matte box assembly  16  or other items to the housing.  
         [0019]    The housing  32  as shown in FIG. 3, is also generally rectangular in shape and has a semi-circular channel  54 , similar to channel  40 , cut into the long side of the housing, which hole runs the entire length of the short side of the housing. The housing  32  also contains a cylindrical hole  42  (the same as hole  42  in housing  30 ) in the housing on the side opposed to the hinge section  36  and cuts through the semi-circular channel  54 . The cylindrical hole  42  does not penetrate through the side of the housing adjacent to the hinge section  36 . The cylindrical hole  42  is sized to receive another multi-jaw cylinder  50  (best viewed in FIG. 10).  
         [0020]    Referring now to FIG. 4, on the free ends of housings  30  and  32  cover plates  58  and  56 , respectfully, are threadably connected to the housings. The plates cover cylindrical holes  42  in both housings. Cover plate  56  contains a hole that runs along the vertical length of the plate and opens toward housing  30 . The hole is sized to receive a threaded bolt  60  so that the bolt can pass through the plate  56  and extend beyond the end of the plate. The side of the bolt opposed to housing  30  contains a handle  62  so that the bolt can be easily turned by hand. Cover plate  58  contains a threaded hole  59  that opens toward housing  32  and is sized and threaded to receive the end of bolt  60  that extends past cover plate  56 . When bolt  60  is inserted into the hole in cover plate  58 , the bolt can be turned using handle  62 , which will close the free end of the clamp about a rod and secure it in place.  
         [0021]    Referring now to FIG. 5, the multi-jaw cylinder will now be described. Each multi-jaw cylinder  50  is sized to fit within the cylindrical hole  42  in housings  30  and  32 . The cylinder  50  contains a stem  64  protruding from one end to receive a selector  66  after the cylinder is placed in the housing. The stem  64  contains a square-shaped end for attaching the selector  66  to the stem. The cylinder, as shown in the preferred embodiment, has three curved sections  68  cut into the sides of the cylinder approximately 120° apart. The cylinder could be made with as few as two curved sections and could be made with more than three curved sections. Each curved section  68  on the cylinder has a different radius, so that when they are placed in the housing, they can be rotated into one of three positions to precisely fit one of three different diameters of rods. Aligned with the center of each of the curved sections is a size indicator  70  marked on the end of the cylinder containing the stem  64 . Adjacent the size indicator is a v-shaped notch  72  that runs along the side of the cylinder from the end containing the stem to the curved section  68 .  
         [0022]    Referring now to FIG. 6, the clamp is shown in the closed position with the multi-jaw cylinders  50  inside the housings  30  and  32 . The multi-jaw cylinders  50  are shown with the selectors  66  attached to the stem  64 . Housings  30  and  32  contain holes  74  in the sides opposite the cover plates  56  and  58  sized to receive the stems  64  of the cylinders  50 . The curved sections  68 , in the preferred embodiment, will have diameters of approximately 0.591 in, 0.622 in. and 0.748 in to fit on conventional iris rods of those diameters. The diameters of the curved sections, however, can be of any size as needed to accommodate the size of the rods that the clamp will be attached to. The diameter of the semi-circular channels  40  and  54  will be larger than the largest diameter of the curved sections  68  on the multi-jaw cylinders  50  to insure that the curved sections  68  extend into the curved channels  40  and  54  for the multi-jaw cylinders to engage the iris rod  14  without the iris rod engaging the housings.  
         [0023]    Referring now to FIG. 7, the top view of the clamp is shown. Adjacent to the hole  74  in each of the housings is a hole  76  so that the size indicator  70  is visible. As the selector  66  is turned, each of the three size indicators comes into view through the hole  76 , which indicators may be numbers, letters or colors. Once the desired diameter is selected and the size indicator is viewable through hole  76 , the multi-jaw cylinder is precisely located and inhibited from further rotation by a ball and spring detent mechanism  78  in which the ball engages the v-shaped notch  72  on the multi-jaw cylinder  50 . The mechanisms  78  are located and retained by setscrews  79  in threaded holes  80 , which are located in the housings  30  and  32 . The hole  80  is located so that the ball of the mechanism  78  will engage the v-shaped notch  72  that is aligned with the curved section  68  that is adjacent to the curved section currently selected. As the setscrew  79  is rotated, it comes into contact with the spring for adjusting the resilient force applied to the ball and, in turn, on the v-shaped notch  72  on the cylinder and inhibits the cylinder from further rotation. As an alternative to the ball and spring detent mechanism, the setscrew,  79  may be longer and directly engage the cylinder  50 , with or without a notch  72 .  
         [0024]    FIGS.  8 A- 8 C diagrammatically indicate the various matching positions of the multi-jaw cylinders  50  apart from the housings  30  and  32 . In FIG. 8A, the two cylinders  50  are in positions so that smallest radius curved sections  68  on the multi-jaw cylinders are aligned. In this position, the multi-jaw clamp would engage with the smallest diameter rod. In FIG. 8B, the two cylinders  50  are in positions so that the largest radius curved sections  68  are aligned. In this position, the multi-jaw clamp would engage with a rod with the largest diameter. In FIG. 8C, the two cylinders  50  are in positions so that the intermediate curved sections  68  are aligned. In this position, the multi-jaw clamp would engage with a rod with the intermediate sized diameter that the clamp could engage.  
         [0025]    Referring to FIG. 9, a cross-section of the clamp in the closed position taken along line  9 - 9  in FIG. 7 is shown. In use, the multi-jaw clamp  10  is slid onto or hinged open and placed on the iris rod  14 . The multi-jaw cylinders  50  are shown in each housing with an iris rod  14  engaged between the cylinders. Threaded bolt  60  is threadably engaged with the threaded hole  59  to lock the clamp in the closed position and tightly on the iris rod in the desired axial position. Also visible is the threaded hole  18  in the protrusion  52  on housing  30  that can be used to attach a matte box  16  or other items. FIG. 10 also shows a cross sectional view of the clamp taken along line  10 - 10  in FIG. 9. The cylindrical hole  42  to receive the multi-jaw cylinders  50  also are shown.  
         [0026]    While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art that other modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the claims that follow.