Multi-jaw clamp

[0002] 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.

[0003] 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.

[0004] 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.

[0005] 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.

[0006] 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;

[0007] FIG. 2 is a front elevation view of the multi-jaw clamp with the matte box assembly mounted on the clamp;

[0008] FIG. 3 is an isometric view of the back of the clamp with the clamp in the open position;

[0009] FIG. 4 is an isometric view of the front of the clamp with the clamp in the open position;

[0010] FIG. 5 is an isometric view of the multi-jaw cylinder;

[0011] FIG. 6 is a front elevation view of the clamp in the closed position;

[0012] FIG. 7 is a top plan view of the clamp in the closed position;

[0013] FIGS. 8A-8C are plan views of the multi-jaw cylinders juxtaposed in three different positions for fitting three different sizes of iris rods;

[0014] 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

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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).

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] FIGS. 8A-8C 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.

[0026] 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.

[0027] 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.