JPH03180002A - Multi-rotation type variable resistor - Google Patents

Abstract

PURPOSE:To eliminate adverse influence to the operation of a clutch by containing a rotation restriction element that abuts the protrusion of a rotor in a housing through a rubber elastic element. CONSTITUTION:When a rotor 2 rotates to the end of its rotating region by an operating shaft 1, a protrusion 9 of the rotor 2 is made to abut on a rotation restriction element 3, and the element 3 is displaced until the gear of the shaft 1 is disengaged from a gear formed on the rotor 2 in a predetermined range. Most of the displacement of the element in this case is absorbed by a rubber elastic element 4, part of the element 4 is compressed to provide a returning operation of the rotor 2 in an opposite direction to the rotating direction by the repulsion force of the elastic element. When the shaft 1 is reversed at the end, the rotor 2 follows up the movement of the gear of the shaft 1. Thus, a fear of damage, etc., of the restriction element is eliminated to obviate malfunction of the operation of a clutch.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multi-rotation variable resistor used in electronic measuring instruments and the like, and particularly to a clutch mechanism at the end of rotation thereof.

(Prior Art) Conventionally, as a clutch mechanism at the end of one rotation in a multi-rotation variable resistor, a clutch mechanism in which a housing and a rotation regulator are integrally formed is known.

The structure of a conventional multi-rotation variable resistor will be explained with reference to FIG. 4 of the accompanying drawings.

A casing 5 having an opening at one end and a part of the target surface, and an operating casing 5 which is inserted through one opening of the casing and has gear-shaped teeth exposed inside the casing. A resistor that is inserted through the shaft l and an opening at the end of one side of the casing, has a resistance element formed on the inner surface of the casing, and has a lead terminal 7 for external extraction that is electrically connected to the resistance element. A rotor 2 is provided with a slider 8 which is in pressure contact with a resistance element of the resistor, and a toothed portion t that meshes with the gear of the operating shaft 1 is formed inside within a certain range. , a protrusion 9 of the rotor 2 for regulating the rotation range of the rotor 2 due to the rotation of the operating shaft l to a certain range, and a rod-shaped rotation regulator 3 that abuts the protrusion. It is formed integrally with the housing 5.

(Problems to be Solved by the Invention) However, in the conventional clutch mechanism, when the protrusion 9 comes into contact with the rotation regulator 3 as the first rotor 2 rotates during clutch operation, the rotation regulator Stress tended to concentrate at the roots. As a result, the rotation restrictor may be damaged or bent in some cases, causing problems such as malfunctions and adverse effects on clutch operation.

The object of the present invention is to solve the aforementioned problems.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a structure in which the rotation regulator 3 that contacts the protrusion 9 of the rotor 2 is housed in the casing 5 via an elastic body 4 made of rubber. The present invention discloses a configuration that has been adopted.

To explain in detail, the rotation regulator 3 is mounted inside a housing with an elastic body 4 made of rubber or the like wrapped around the outer periphery thereof.

(Function) According to the present invention, when performing clutch operation, the operating shaft l
When the rotor 2 rotates to the end of the rotation range, the protrusion 9 of the rotor 2 comes into contact with the rotation regulator 3, and the gear on the operating shaft l and the gear formed in a certain range of the rotor 2 come into contact with each other. The rotation regulator 3 is displaced until the mesh is disengaged. At this time, most of the strain caused by the displacement of the rotation regulator is caused by the rubber elastic body 4.
, a part of the elastic body 4 is compressed, and the repulsive force of this elastic body has the effect of pushing back the rotor 2 in the opposite direction to the rotation direction, and even if the operating axis l is reversed at the end, the rotation will not continue The element 2 is configured to follow the movement of the gear on the operating shaft l, and it is possible to prevent stress from concentrating on the root of the rotation regulator 3 due to the deformation of the elastic body 4.

(Example) The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view of a multi-rotation variable resistor according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA' in FIG. 1, and FIG. 3 is an exploded perspective view.

A casing 5 having an opening on one end and a part of the opposite surface; and an operating shaft 1 inserted through one opening of the casing so that gear-shaped teeth are exposed inside the casing. and a resistor 6 which is inserted through the opening at the end of one side of the casing, has a resistance element formed on the inner surface of the casing, and has a lead terminal 7 for external extraction electrically connected to the resistance element. , a rotor 2 having a slider 8 attached thereto which presses against the resistance element of the resistor, and a rotor 2 having teeth t meshing with the gears of the operating shaft 1 formed inside within a certain range; In order to define the rotation range of the rotor 2 due to the rotation of the shaft 1 in a certain range,
The rotor 2 has a protrusion 9 of the rotor 2 and a rod-shaped rotation regulator 3 that abuts on the protrusion, and the rotation regulator 3 is attached to the casing 5 via an elastic member 4. The elastic member 4 may be attached to the outer periphery of the rotation regulator 3.

To explain the operation of the clutch mechanism, see Figure 5 (&).
, the rotor 2 is rotated in the direction of the arrow CW force by the operating shaft 1, and when it rotates to the end of the rotation range, the protrusion 9 of the first rotor 2 comes into contact with the rotation regulator 3, and the gear of the operating shaft 1 is rotated. The rotation regulator 3 is displaced until the gear t formed in a certain range of the rotor 2 is disengaged (see FIG. 5(b)).

At this time, most of the strain caused by the displacement of the rotation regulator 3 is absorbed by the elastic body 4 such as rubber wrapped around the rotor 3, and a part of the elastic body 4 such as rubber is compressed. The repulsive force acts to push the rotor 2 back in the CCW direction opposite to the rotation direction, and even if the operating shaft 1 is reversed at the end, the rotor 2 follows the movement of the gear on the operating shaft 1. (Fig. 5(C)).

Due to this structure, the strain at the root caused by a large displacement of the one-rotation regulator 3 is caused by the deformation of the elastic body 4 such as rubber, and is caused by stress concentration on the rotation regulator 3. Damage can be prevented.

(Effects of the Invention) As explained in detail above, according to the present invention, when the variable resistor is operated, the stress applied to the root of the rotation regulator by coming into contact with the protrusion of the rotor is absorbed by the rubber or the like. Since the stress can be absorbed by the deformation action of the elastic body, concentration of stress on the rotation regulator is prevented. Therefore, there is no fear of damage to the one-turn regulator, and there are effects such as eliminating problems in clutch operation and contributing to improving the efficiency of the variable resistor.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of a variable resistor according to the present invention. FIG. 2 is a sectional view taken along the line A-A' in FIG. FIG. 3 is an exploded perspective view of FIG. 1. FIG. 4 is a sectional view showing a conventional clutch mechanism. 1... Axis for operation 2...Rotor 3...Rotation regulator 4...Elastic body 5... Housing 6...Resistor 7...Lead pin 8...Slider 9... Rotor protrusion

Claims (2)

[Claims] 1. a casing having an opening on one end and a part of the target surface; an operating shaft inserted through one opening of the casing and having gear-shaped teeth exposed inside the casing; a resistor that is inserted and attached through an opening at one end of the housing, has a resistive element formed on the inner surface of the housing, and has a lead terminal for external extraction that is electrically connected to the resistive element; A rotor is provided with a slider that presses against the resistance element of the resistor, and has gear teeth formed in a certain range on its inner surface to mesh with the gears of the operating shaft, and rotation of the operating shaft. A multi-rotation variable resistor comprising a protrusion of the rotor for regulating the rotation range of the rotor within a certain range, and a rod-shaped rotation regulator that abuts the protrusion. A multi-rotation type variable resistor that has a clutch mechanism in which a rotation restrictor, which a child protrusion comes into contact with, is housed in a housing via an elastic body. 2. The multi-rotation type variable resistor according to claim 1, wherein an elastic body is wound around the outer periphery of the rotation regulator.