JPS5850321Y2 - Sighting device focusing mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanism for accurately and repeatedly focusing a lens assembly over a relatively wide range of distances.

This mechanism of the present invention is particularly applicable to the objective part of a gun scope, and does not require a cam or a spring for its operation.

Many manufacturers of rifle telescopes use adjustable objective lens assemblies to eliminate parallax at various aiming distances of their high power scopes.

Although it is desirable to be able to make adjustments over as wide a range as possible, scope-specific conditions limit such objectives.

For example, since an ordinary scope has a sight distance marker calibrated at the end of its objective, the distance must be adjusted over its entire range in slightly less than one rotation of the adjustment mechanism.

For this reason, scopes typically include a stop that prevents the adjustment mechanism from making more than one revolution.

Another condition that limits scope magnification adjustment is that the gun to which the scope is attached is subject to repeated strong recoil each time the gun is fired.

In order to prevent the adjustment mechanism from rotating unexpectedly due to such a reaction force and thereby causing the lens to go out of focus, the slope of the thread of the cam or screw in the adjustment mechanism must be made small.

However, such a small tilt necessarily limits the amount by which the lens can be moved when the adjustment mechanism is rotated.

Furthermore, if the aiming distance is very short [approximately 15m (5Q
ft) or less] requires large movements of the lens.

For the focusing mechanism of a gun's telescopic sight, a screw mechanism is better than a cam mechanism because the contact area is larger.

The larger the contact area, the greater the friction, and therefore the less affected by the recoil of the shot.

Furthermore, regarding the screw mechanism, from the viewpoint of fitting accuracy, a fine screw mechanism is better than a coarse screw mechanism.

The focusing mechanism of the present invention uses a combination of left-handed and right-handed screws in order to increase the amount of lens movement when the mechanism is turned.

One of the screws is preferably a three-thread screw, and the other is a single-thread screw, thereby achieving the effect of a four-thread screw.

This mechanism allows the use of fine thread screws with relatively small lead angles, and does not require springs or cams to operate.

Therefore, an object of the present invention is to provide a lens/focusing mechanism that can repeatedly and accurately adjust focus over a wide range of aiming distances.

Another object of the present invention is to achieve full range focusing in one part of the mechanism.
It is an object of the present invention to provide a focusing mechanism that can perform focusing with less than rotation.

Still another object of the present invention is to provide a focusing mechanism that can be operated without the use of cams or springs and has superior strength against gun recoil.

These and other objects and advantages of the mechanism of the present invention include:
BRIEF DESCRIPTION OF THE DRAWINGS It will be more clearly understood from the details of the preferred embodiments of the invention given below in conjunction with the accompanying drawings.

The drawings show a preferred embodiment of the lens focusing mechanism of the present invention, which is incorporated into the objective end of a gun telescope or scope 2. FIG.

The scope 2 includes a bulging objective bell 4 integral with the barrel of the scope, into which a set 6 of objective lenses and a focusing mechanism are incorporated.

Lens set 6 is secured within lens cell 8, which is threaded into lens cell housing 10 and held in place by lens cell retaining ring 14.

When assembled, objective lens set 8 is 91.4 m
It is focused on a known target (100 yards) away and then fixed in position by the retaining ring 14.

The lens cell housing 10 is formed with an axially extending outer spline 11 which includes:
It mates with internal splines formed on the barrel extension 16 to allow axial movement of the lens cell housing 10 back and forth, but not axial rotation.

The extension 16 is threaded into the objective bell 4 and has an axially projecting stop tab 28 formed on the extension 16.
is fixed in a fixed position aligned with the index on the scope barrel.

Graduated collar 22 is threaded onto extension 16 with fine thread right hand threads, and lens cell housing 10 is threaded onto graduated collar 22 with fine three thread left hand threads 30 and 34.

FIG. 2 clearly shows the features of a triple thread screw 30 having three threads (A, B, C) provided on the lens cell housing 10.

A set screw 26 is threaded onto the graduated collar 22 and engages opposite sides of a stop tab 28 to form a stop for perspective rotation of the collar 22.

The graduated collar 22 is provided with a distance display scale on the outside, and by aligning this scale with a reference mark attached to the outside of the objective bell 4, the distance at which the scope is in focus is displayed.

This is the same as a general aiming device.

Lens Cell Housing Insert 18 or Luns
Press fit into the cell housing 10 to prevent harmful reflected light from entering the scope.

The 01J rings 12, 20, and 24 are sealed to prevent moisture and dust from entering the end of the objective and to prevent nitrogen gas sealed inside the scope from leaking.

This focusing mechanism is operated as follows.

The lead of the single right-hand screw connecting the graduated collar 22 and the extension 16 is 0.0208 in (0.5 in) per revolution.
2832mm), and its right-hand thread is l 1n (25
, 4mm) with 48 threads per fine thread.

Scale size collar 22 and lens cell housing 1
The three-start left-hand screw 30.34 that connects 0 is also a fine thread (48 threads per inch).

However, since this left-hand thread is a three-start thread, the lead is 0.0625 inches (1,5875 mm) per revolution.

When graduated collar 22 is turned clockwise (as viewed from the objective end side of the scope), collar 22 is moved toward the eyepiece end due to the right-hand thread between it and extension 16.

This movement is 0.0208 in (0,52
832 mm), that is, the lead of 48 fine threads per lin.

At the same time, the left-hand threads 30, 34 between the collar 22 and the lens cell housing 10 cause the housing 10 to move 0.0625 i per revolution toward the eyepiece end of the scope.
n (1,5875 mm), i.e. 48 per lin
It is moved at the rate of the lead of the three thread fine thread of the mountain.

The combined rate of movement of the lens cell housing 10 is therefore 0.0833 in. (2.11582 mm) per revolution of the two screw leads combined.

By selecting an appropriate lens, the focusing distance of the objective lens can be increased from 15 m (50 ft) to infinity.

Needless to say, if the collar 22 is surrounded in a counterclockwise direction,
The lens cell housing 10 is moved forward at the same rate.

As can be seen from the above description, the focusing mechanism of the present invention does not require parts such as springs or cams, and can focus over a wide range of distances with one rotation of the focusing member.

Furthermore, the mechanism of the present invention uses a fine-threaded screw and allows the lens to be moved as much as necessary, ensuring a precise fit and allowing the lens to be moved even when subjected to strong axial forces such as recoil from a gun. It is possible to apply a large frictional force to keep the material from moving.

The embodiments of the invention described herein are capable of many variations without departing from the spirit of the invention, and the invention is therefore limited only by the scope of the utility model claims.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of the objective end of a gun telescope equipped with a preferred embodiment of the lens/focusing mechanism of the present invention, and FIG. FIG. 2...Telescope, 6...Lens, 8
・・・・・・Lens cell, 10・・・・・・Lens・
Cell housing, 11... Spline, 16
... Barrel extension, 22 ... Graduated collar, 26 , 28 ... Stop, 30
, 34...Three-thread left-hand thread.

Claims (4)

[Scope of utility model registration request] (1) As a gun sight, a mechanism for moving the lens members of the sight a predetermined distance in the axial direction in order to mutually focus on a certain distance range is a, and the mechanism is connected to the sight through a first screw. b. a lens housing coupled to the operating collar via a second screw and accommodating the lens member; and C0 provided on the sight and preventing rotational movement of the housing. d. a stop device that limits the rotation of the actuating collar with respect to the sight to only approximately one rotation; one of the second screws is a right-handed screw and the other screw is a left-handed screw, and one of the first and second screws is one or more multi-thread screws; A sighting device characterized in that the sum of leads per rotation of the right-hand thread and the left-hand thread is equal to a predetermined distance of axial movement of the lens member. (2) Utility Model Registration Scope of the Claims The sight according to claim 1, wherein one of the first screw and the second screw is a three-thread screw, and the other is a single-thread screw. (3) Utility Model Registration The sight according to claim 2, wherein both of the screws are fine threads. (4) The sight according to claim 1, wherein the second screw is a triple thread screw.