JPH03203707A - Lens barrel - Google Patents

Abstract

PURPOSE:To freely set the clearance quantity of fitting to a cam groove without spoiling assembling workability by slipping a cam follower in a hole bored in a fixed cylinder, and fitting its tip part in the cam groove, then inserting and expanding a screw in a hole bored in the center of the cam follower, and adjusting the clearance to a cam mechanism. CONSTITUTION:The cam follower 3 which engages the cam groove 2b is fitted in the hole 1b formed in the fixed cylinder 1 from outside and the tip part of the cam follower 3 is projected from the fixed part to the internal-diameter side and also fitted in the cam groove 2b. Then the screw 4 is engaged threadably with the hole 3c formed in the center of the cam follower 3 and fixed to the fixed cylinder 1 by expanding the screw 41 and the screw 4 is screwed in to expand its tip little by little, thereby adjusting the clearance to the cam groove 2. Consequently, the lens barrel having the cam follower which has good operability and can be adjusted continuously is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lens barrel having a cam barrel on the inner diameter of a fixed barrel.

[Conventional technology]

Conventionally, a cam follower for a lens barrel with a cam barrel placed on the inner diameter side of a fixed barrel has the following methods: (1) A tool hole is drilled at the exact opposite position of the cam follower and screwed in from the inner side (2) A simple press-fit roller is used. (3) In either case 1 or 2 above, the diameter of the cam follower is adjusted and those with different diameters are selected and used. (4) The protrusion is integrally molded on the fixed cylinder.

Such measures are being taken.

[Problem that the invention is trying to solve]

However, in the above conventional example, (1) screw fixing method from the inside has poor assembly work efficiency, and (2) press-fitting method, the diameter of the cam follower varies widely, and it is necessary to have many different diameters to obtain the optimal diameter. You need to prepare the following items. Also, once you overpower the cam follower,
It is difficult to remove the cam follower when the cam follower is integrally molded in (4).
In order to incorporate the cam cylinder, the cam groove must be opened to the end of the cam cylinder, which is disadvantageous in the arrangement of the cam groove.

There were drawbacks such as.

[Failure to solve the problem]

According to the present invention, in a lens barrel in which a cam barrel having a cam groove is disposed inside a fixed barrel, a cam follower that engages with the cam groove is inserted from the outside of the fixed barrel through a hole provided in the fixed barrel. At the same time, the tip of the cam follower protrudes inwardly from the fixing part and fits into the cam groove, and then a screw is screwed into a hole provided in the center of the cam follower to inflate it, thereby fixing the cam follower. It is characterized by a lens barrel that is fixed to a cylinder and further expands little by little by screwing in a screw, thereby making it possible to adjust the backlash with the cam groove.

According to the present invention, it is possible to provide a lens barrel having good workability and a cam follower that can be continuously adjusted.

[Example] Figures 1 and 2 show this example. Figure 1 is an assembled sectional view around the optical axis, and Figure 2 is an exploded perspective view of parts. 91 is a fixed cylinder, and the inner diameter A hole having a fitting hole 1b, a receiving part IC, and a notch part 1d is provided at three equal positions of the fitting part 1a and the outer circumferential part. Reference numeral 2 denotes a cam cylinder, and an outer circumferential portion 2a thereof is fitted with an inner diameter fitting portion 1a of the fixed cylinder 1.

Moreover, 2b is a cam groove provided in three equal parts in the cam cylinder 2. 3 is a cam follower, and 3a is a fitting portion having an end face 3d and fitting into the fitting hole 1b of the fixed cylinder 1 to form a fitting portion A. 3b is a fitting portion that fits into the cam groove 2b of the cam cylinder 2 and constitutes a fitting portion B. As shown in FIG. 3e is a rotation stopper on the outer periphery. There is also a hole 3C in the center. 4 is a screw. It is assumed that the fitting clearance of the fitting part A is set to be equal to or slightly smaller than the fitting clearance of the fitting part B in the state of a single component. Further, the inner diameter of the center hole 3C of the cam follower 3 is set smaller than the outer diameter of the threaded portion of the screw 4.

Next, in the above configuration, the fixed barrel 1 and the cam barrel 2 are fitted together, and the cam follower 3 is inserted into the cam follower 3 with the cam groove 2b of the cam barrel 2 aligned with the hole of the fixed barrel 1. Fit the rotation stopper 3e and the notch 1d of the fixed cylinder 1 together. Next, when the nivis 4 is screwed into the center hole 3C of the cam follower 3, the fitting part 3a of the cam follower 3 expands, the fitting part A is tightened, and the fixed cylinder 1
And Cam Follower 3 becomes one. When the screw 4 is further screwed in, the fitting part 3b of the cam follower 3
begins to bulge, and the fitting clearance of the fitting portion B can be reduced by adjusting the screwing condition of the screw 4.

〔Effect of the invention〕

As explained above, the use of the cam follower of the present invention has the effect of allowing the amount of fitting clearance between the cam groove and the cam groove to be freely set without impairing the workability of assembly.

[Brief explanation of drawings]

Figure 1 is an assembled cross-sectional view in which the present invention is implemented. Figure 2 is an exploded perspective view of parts implementing the present invention. 1. Fixed cylinder 1a: Inner diameter fitting part 1b: Fitting part IC: Ukeha Department 1d: Notch 2. Cam tube 2a: Outer periphery 2b: Cam groove 3. Cam follower 3a: Fitting part 3b: Fitting part 3C: Center hole 3d: End face 3e: Stop rotation 4, screw Figure 2

Claims (1)

[Claims] In a lens barrel in which a cam barrel having a cam groove is arranged inside a fixed barrel, a cam follower that engages with the cam groove is fitted into a hole provided in the fixed barrel from the outside of the fixed barrel, and After the tip of the cam follower protrudes inward from the fixed part and is fitted into the cam groove, a screw is screwed into the hole provided in the center of the cam follower to inflate it, thereby attaching it to the fixed cylinder. A lens barrel that is fixed and further expands little by little by screwing in a screw, making it possible to adjust the play with the cam groove.