JPH03284803A - Slide type variable resistor - Google Patents

Abstract

PURPOSE:To eliminate instability of contact between a sliding piece and an electrode at an end in a sliding type variable resistor used for speed control of sewing machines, etc., by providing an elastic part at the end of the inside of a cover so that after the slider is forced to slide by a lever to the end, pushing force is removed to let the sliding piece return by elasticity from a deposit of powder produced by abrasion. CONSTITUTION:A spring 14 is installed on an end of the inside of a metallic cover 11 having a long port 12 on its top from which a lever 10 provided on a slider 9 protrudes. When, after a pushing pressure is applied to the slider 9 against the spring 14 to the end, the pushing pressure on this slider 9 is removed, the slider 9 returns slightly as it is pushed by the spring 14 and a sliding piece 15 also returns a little to detach itself from the abrasion-produced powder, maintaining stability of contact between the sliding piece 15 and an electrode 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a slide type variable resistor used for speed control of sewing machines and the like.

2. Description of the Related Art A conventional slide type variable resistor for controlling the speed of a sewing machine or the like will be explained with reference to an exploded perspective view of FIG. According to the figure, 1 is an insulating substrate having a resistance path 4 having electrodes 2 and 3 at both ends and a conductive path 5 provided on its surface in parallel with this resistance path 4, and 6 and 7 are connected to the electrodes 2 and 3, respectively. 8 is an outer terminal fixed to the conductive path 5; 10 is an external terminal that bridges the resistive path 4 and the conductive path 5;
This is a slider on which a slider 15 for sliding contact is mounted on the lower surface, and 11 is a metallic slider having the insulating substrate 1 attached to the opening on the lower surface and a long hole 12 on the upper surface from which the lever 10 provided on the slider 10 projects. It's a cover.

Problems to be Solved by the Invention A circuit for controlling the current of a conventional variable resistor (
When used in a so-called rheostat system, especially when used for a long period of time to control the speed of a sewing machine, the sliding abrasion powder generated between the slider 15 and the resistance path 4 is transferred to the electrode 2, which is the sliding end of the slider 9. 3, and the slider rides on this high-resistance abrasion powder, causing the resistance value of the variable resistor to become high or unstable, causing speed control at the end of the resistance value adjustment of the variable resistor. The problem was that the speed became unstable.

Means for Solving the Problem In order to solve the above problem, an elastic part is provided at the inner end of the cover, and after the slider is forcibly slid to the end by a lever, when the forced force is removed, the elastic part will cause the slider to slide. This is a composition in which Ida returns slightly.

Function As mentioned above, the elastic part is provided on the inside edge of the cover. After the slider is forcibly slid to the end, when the force applied to the lever of the slider is removed, the slider returns slightly from the end and the slider stops sliding. The mover is slightly shifted from the location where wear debris has accumulated, thereby stabilizing the resistance value at the end.

Embodiment A slide type variable resistor which is an embodiment of the present invention will be explained with reference to FIGS. 1 and 2. FIG. 1 is an exploded perspective view,
Figure 2 is a cross-sectional view of the bond. In addition, in the explanation, the same numbers are given to the same parts as in the prior art, and the explanation will be omitted. 13 is the lever 10 provided on the slider 10 on the upper surface while attaching the insulating substrate 1 to the opening on the lower surface.
It is a metal cover having a long hole 12 from which 1
Reference numeral 4 designates a leaf spring attached to the inner g4 end of this cover 13.

According to the embodiment described above, the slider 9 is moved until the leaf spring 1 reaches the end.
4 and then when the pressure applied to the slider 9 is removed, the slider 9 is pushed back by the leaf spring 14 and returns slightly, and the slider 15 also moves back slightly within the electrode 13 and accumulates. This is to ensure the stability of the contact between the slider 15 and the electrode 13 by keeping it away from the abrasion powder.

In the above embodiment, the leaf spring 14 is attached to the inner end of the cover 13, but an elastic body such as a coil spring may be attached to the inner end. A coil spring may be attached or a slit may be provided at the end of the formed body forming the slider 9 to form an elastic portion that comes into contact with the end of the cover.

Effects of the Invention As is clear from the above embodiments, the present invention is one in which an elastic body is attached to the inner end of the cover, and a large amount of abrasion powder is generated due to the sliding contact of the slider. Even if it accumulates,
The slider is a device that can remove the pushing force (and use an elastic body to move the slider back from the area where wear particles accumulate at the end), thereby reducing the instability of the contact between the slider and the electrode at the end. It is.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of one embodiment of a sliding variable resistor according to the present invention, and Fig. 2 is a sectional view of the same side.
The figure is an exploded perspective view of a conventional sliding type variable resistor. 1... Insulating substrate, 2, 3... Electrode, 4
...Resistive path, 5... Conductive path, 6.7.
8...Outer terminal, 9...Slider 1
0... Lever 11... Cover 12...
...Long hole, 13 ...Inner end of cover, 1
4...Plate spring, 15...Slider.

Claims (2)

[Claims] (1) An insulating substrate having a resistance path and a conductive path provided on its surface with electrodes at least on both ends, an external terminal connected to each of the resistance path and the conductive path, and sliding contact on the resistance path and the conductive path. A slider, a slider with the slider attached to the lower surface thereof, and an elongated hole provided in the slider from which a lever projects, and an elastic body attached to an inner end of the slider are slidably housed. A sliding type variable resistor consisting of a cover. (2) an insulating substrate having a resistive path and a conductive path provided on its surface with electrodes at least on both ends; an external terminal connected to each of the resistive path and the conductive path; A slider that comes into sliding contact, a slider with the slider attached to the lower surface thereof, and a metal cover that slidably houses the slider and has an elongated hole that allows a lever provided on the slider to protrude. A sliding variable resistor comprising an elastic part that abuts an inner end of the cover provided on the slider.