JPH0343518Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an elevation mechanism for raising and lowering a vertical rod pivotally mounted on the top of a tripod for a camera or video camera.

[Prior Art] Conventionally, in a tripod for a camera or video camera, a vertical rod with a pan head attached to the top end is attached to the top of the tripod so as to be slidable in the vertical direction, so that the height position of the camera can be changed. Tripods equipped with an elevation mechanism are used, and the elevation mechanism of this type of tripod generally has a structure as shown in Figure 4, with the three base legs 5 of the tripod surrounding the tripod.
A vertical rod 52 with a pan head 53 fixed to the top end is attached to a top metal fitting 51 with the ends of 0, 50, 50 equally spaced and swingably pivoted, via a rack and pinion type lifting mechanism. It has a pivot. That is, the top metal fitting 5
A vertical rod 52 is installed to be slidable in the axial direction with respect to a thrust bearing hole 53 bored in the shaft 1, and a rack gear 54 with gears cut in the axial direction is formed on one side of the vertical rod 52, and a pinion gear 55 meshes with the rack 54. is pivoted to the top metal fitting 51 and rotated by an elevation handle 56 to move the vertical rod 52 up and down.

[Problem to be solved by the invention] However, in this type of tripod, each member is generally made of aluminum to reduce weight.
The vertical rod 52 of the elevation mechanism is also made of aluminum. Therefore, the rack gear 56 formed on the vertical rod 52 must be subjected to "gear cutting" by precision machining after the rod is molded, which poses the problem of increasing manufacturing man-hours and increasing production costs. Ta.

Furthermore, due to the meshing of the rack gear 56 and the pinion gear 55, the rack gear 56 of the vertical rod 52, which has relatively poor wear resistance, wears out and becomes loose, which is particularly important when using a video camera in an elevator. It also has the disadvantage that the operation sound of the camera mechanism intrudes into the camera's microphone, making the video production unpleasant.

The present invention was created in view of these problems, and provides a tripod elevation mechanism with a new configuration that can maintain product accuracy, facilitate quality control, and reduce manufacturing costs at the same time. It is an object of the present invention to provide a tripod elevation mechanism that does not cause rattling, can therefore make operation noise quiet, and has excellent operability and quietness.

[Means for Solving the Problems] The tripod elevation mechanism according to the present invention includes a vertical rod that is pivotably mounted on the top metal fitting of the tripod so as to be able to rise and fall freely, and a rack gear that is configured by cutting gears on the vertical rod as separate members. The purpose of the present invention is to solve the above problem by configuring the tripod to have three base legs, each end of which is equally spaced around the periphery and swingably pivoted. In a tripod elevation mechanism, a vertical rod with a pan head fixed to the top end is mounted on a shaft that can be raised and lowered freely via a rack-and-pinion type lifting mechanism, and the vertical rod is made of aluminum. At the same time, a separate rack member having a rack gear cut in the axial direction on one side of the vertical rod is fixed and integrated, and a pinion gear shafted on the top metal fitting is meshed with the rack gear. This is the summary.

Further, it is preferable that the above-mentioned rack member is molded from a suitable synthetic resin and is fitted from the axial direction into a dovetail groove provided on one side of the vertical rod.

[Function] Therefore, in the above structure, the rack member molded from a separate member is fixed to one side of the vertical rod made of aluminum drawer, so that the rack gear can be formed without gear cutting. As a result, highly accurate rack gears can be obtained.

In addition, since the rack member is obtained by molding, it is possible to use various moldable materials such as synthetic resin. For example, when synthetic resin is used, the wear resistance with the pinion gear is dramatically improved. In addition to eliminating the rattling of the thrust bearing due to wear, by selecting the elasticity, it is possible to reduce the meshing noise of the rack gear and pinion gear, which has the effect of reducing the operation noise when the vertical rod is raised and lowered.

[Embodiment] An embodiment of the tripod elevation mechanism according to the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a partially cutaway sectional view showing the head of the tripod, in which the base ends of the three base legs 1, 1, 1 are connected around the top metal fitting 2, which has a thrust bearing hole 3 in the center. The thrust bearings 3 and 3 are pivotably and equidistantly mounted via pin shafts 4, and a cylindrical shaft 10 whose inner diameter is continuous from the lower end of the thrust bearing 3 is provided.

Reference numeral 5 denotes anti-rotation protrusions 6, 6 which are slidably inserted into the thrust bearing hole 3 of the top metal fitting 2 in the axial direction and protrude from the inner wall of the thrust bearing hole 3.
It is a vertical rod in which guide grooves 7, 7 extending in the axial direction are fitted so as to be slidable in the axial direction, and the lower end is inserted into the cylindrical shaft 10, and the vertical rod 5 is made of aluminum. It is formed as a puller, and a dovetail groove 8 extending in the axial direction is formed on one side, and a retaining upper end member 9 for fastening a pan head (not shown) is fixed to the upper end, and a retaining lower end member 10 is fixed to the lower end. . Reference numeral 11 is a rack member made of synthetic resin having appropriate elasticity;
The base is formed by a mold and fits into the dovetail groove 8 in the axial direction, and the rack gears 12 arranged in parallel in the axial direction are formed on the outer arcuate circumferential surface, and small holes 13 are bored at both ends. , 13, and are screwed into the bottom wall of the dovetail groove 8 to be integrated.

Further, a pinion gear 15 rotatably installed in the top metal fitting 2 so as to face the thrust bearing hole 3 meshes with the rack gear 12 of the rack member 11 inserted into the thrust bearing hole 3, and also engages with the rack gear 12 of the rack member 11 inserted into the thrust bearing hole 3. The pinion gear 15 is preferably molded from the same synthetic resin as the rack member 11.

In addition, the reference numeral 18 in the figure is a support rod holding ring that is slidably fitted onto the cylinder shaft 10 that extends continuously downward from the thrust bearing hole 3 of the top metal fitting 2, and the base legs 1, 1, The support rod 19, which connects between 1 and 1
It is made by pivoting one end of 9 and 19. Further, reference numeral 20 denotes a retaining ring 21 fixed to the lower end of the cylinder shaft 10.
This is an O-ring that is used to cushion collisions.

[Effects of the invention] As described above, according to the tripod elevation mechanism having the above structure, the rack member is molded as a separate member, and can be obtained by molding a material different from that of the vertical rod. Therefore, a highly accurate rack gear can be constructed without carrying out gear cutting of the rack gear, and an increase in production costs due to gear cutting can be eliminated. In addition, since the rack member is obtained by molding, it is possible to use various moldable materials such as synthetic resin, and by molding it with synthetic resin, the wear resistance with the pinion gear is dramatically improved. In addition to eliminating the rattling of the thrust bearing due to wear, it also makes it possible to reduce the meshing noise between the rack gear and pinion gear, and eliminates the operation noise when the vertical rod is raised and lowered. The practical effects after implementing this invention are extremely large.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway sectional view of the tripod head showing an embodiment of the tripod elevation mechanism according to the present invention, Fig. 2 is an exploded perspective view of the main parts, and Fig. 3 is the first embodiment of the tripod elevation mechanism according to the present invention.
FIG. 4 is an enlarged cross-sectional view taken along the line A--A in the figure, and FIG. 4 is a cross-sectional view of essential parts of a tripod elevation mechanism showing a conventional device. DESCRIPTION OF SYMBOLS 1... Base leg, 2... Top metal fitting, 3... Thrust bearing hole, 5... Vertical rod, 6... Anti-rotation protrusion, 7...
...Guide groove, 8...Dovetail groove, 10...Cylinder shaft, 11...
... Rack member, 12 ... Rack gear, 14 ... Tapping small screw, 15 ... Pinion gear, 16 ...
...Rotation axis, 17...Elevation handle.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The three base legs of the tripod have a cloud at the top end for a thrust bearing hole drilled in the top metal fitting which is equally distributed around the periphery and swingably pivoted. In a tripod elevation mechanism in which the vertical rod to which the base is fixed is mounted on a shaft so that it can be raised and lowered freely via a rack-and-pinion type lifting mechanism, the vertical rod is formed from an aluminum drawer, and the vertical rod is A tripod elevation mechanism characterized in that a rack member, which is a separate member in which a rack gear is gear-shaped in the axial direction, is fixed and integrated on one side, and a pinion gear axially installed on the top metal fitting is meshed with the rack gear. . (2) The tripod according to claim 1, wherein the rack member is a rod formed of a suitable synthetic resin, and is integrally fitted from the axial direction into a dovetail groove formed on one side of the vertical rod. Elevation mechanism.