JPH11195509A - Variable resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To return a resistance value to an initial value by automatically returning a knob to an original place, when a hand is separated from the knob. SOLUTION: A variable resistor has a shaft 3 varying a resistance value in a variable resistor body 2 by rotation, a knob 4 fixed onto the shaft 3, a protruding section 12 fastened onto the knob 4, a stopper 10 installed on the main body 2, and a spring 13 in which one end is fixed onto the knob 4 and the other end is fastened on the main body 2 and which makes the protruding section 12 abut against the stopper 10 and returns the knob 4 to an initial position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a variable resistor for varying the resistance of an electric circuit.

[0002]

2. Description of the Related Art In a conventional variable resistor, a knob is fixed to a rotating shaft derived from a variable resistor main body, and the knob is manually rotated to change a resistance value in the main body and set a resistance value. I have.

When an object is repeatedly moved from a certain position to another position by a motor M as shown in FIG. 3 by an elevator or the like, for example, a push button switch SW of a motor circuit is pressed and a variable resistor R is pressed. Rotate the knob to set the resistance value, adjust the speed of the motor M, when the object moves, release the push button switch SW, return the knob of the variable resistor R to the original position, The above operation is repeated.

[0004]

In the case of the conventional variable resistor, since the knob is rotated to change the resistance value and the knob and the resistance value are kept as long as the hand is released, the variable resistor is connected to the motor. When used in a circuit, if you forget to return the knob to its original position, the resistance value remains at the set value, and pressing the push button switch SW activates the motor at high speed, leading to an accident. is there.

In the present invention, when the knob is released, the knob automatically returns to the original position, the resistance value returns to the initial value, and the knob is returned to the original position each time. An object of the present invention is to provide a variable resistor that does not need to be generated and prevents occurrence of an accident.

[0006]

In order to solve the above-mentioned problems, a variable resistor according to the present invention comprises a rotating shaft for varying a resistance value in a variable resistor main body by rotation, and a knob fixed to the rotating shaft. A protrusion fixed to the knob, a stopper provided on the main body side, one end fixed to the knob, the other end fixed to the main body side, and the protrusion abutting on the stopper. And a spring for returning the knob to the initial position.

Therefore, the protrusion is fixed to the knob, the stopper is provided on the variable resistor main body side, and both ends of the spring are fixed to the knob and the main body side. When the knob is released, the knob returns to the original position by the spring, and the resistance value returns to the initial value (maximum or minimum). It is not necessary to return the knob to the original position each time. Accidents are prevented,
It has a remarkable effect when used in an electric circuit that must always start from an initial value for each setting and control.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. Reference numeral 1 denotes a mounting panel, 2 denotes a variable resistor main body mounted on the panel 1, and 3 denotes a rotating shaft extending upward from the main body 2, and a resistance value in the main body 2 is changed by rotation of the rotating shaft 3. 4 is a knob, 5 is a circular recess formed on the bottom surface of the knob 4, and 6 is an insertion hole formed in the center of the upper surface of the recess 5.

Reference numeral 7 denotes an insertion hole formed from the side surface of the knob 4 to the insertion hole 6 side, 8 denotes a screw hole formed from the tip of the insertion hole 7 to the insertion hole 6, and 9 denotes a set screw for fixing the shaft. Yes,
With the rotating shaft 3 inserted into the insertion hole 6, the screw 9 is inserted through the insertion hole 7 and screwed into the screw hole 8, and the tip of the screw 9 presses the rotating shaft 3, and the knob 4 is attached to the rotating shaft 3. Has been fixed.

Reference numeral 10 denotes a stopper made of a screw, which is inserted into the panel 1 and fixed by a nut, and is located in the recess 5 of the knob 4. Reference numeral 11 denotes a mounting-side spring fixing screw, which is fixed to the panel 1 by a nut similarly to the stopper 10, and is located in the concave portion 5. Reference numeral 12 denotes a protrusion which also serves as a knob-side spring fixing screw, which is screwed and fixed to the upper surface of the concave portion 5 and located on the same circumference as the stopper 10 with respect to the rotating shaft 3.

Reference numeral 13 denotes a double-wound spring, one end of which is fixed to the projection 12 and the other end of which is fixed to the mounting-side spring fixing screw 11. In FIG. 2, the knob 4 is urged counterclockwise. When the hand is released from the knob 4, the protrusion 12 comes into contact with the lower surface of the stopper 10.

FIG. 2 shows that the knob 4 is rotated approximately half a clockwise direction against the spring 13 from an initial state in which the protrusion 12 is in contact with the lower surface of the stopper 10, that is, from the initial value (maximum or minimum). When the knob 4 is further rotated approximately half a clockwise direction, the protrusion 12 comes into contact with the upper surface of the stopper 10, and the resistance value becomes minimum or maximum.

When the hand is released from the knob 4, the spring 1
3 causes the knob 4 to rotate counterclockwise in the reverse direction,
Abuts against the stopper 10, and the initial state, that is, the resistance value becomes the initial value.

Therefore, by releasing the hand from the push button switch SW in FIG.
Even if the knob 4 is returned to the initial state and the push button switch SW is pressed next time, the motor M does not operate at a high speed, and the occurrence of an accident is prevented. The stopper 10 and the mounting-side spring fixing screw 11 may be attached to the panel, or may be attached directly to the variable resistor main body 2 or integrally with the main body 2 via an attachment plate.

[0015]

Since the present invention is configured as described above, it has the following effects. The protrusion 12 is fixed to the knob 4, and the stopper 1 is
0 is provided, and both ends of the spring 13 are fixed to the knob 4 and the main body 2 side. After setting the resistance value with the knob 4 and using the knob, if the hand is released from the knob 4, the knob 13 causes the spring 4 to Return to the original position, the resistance value becomes the initial value (maximum or minimum), it is not necessary to return the knob 4 to the original position each time, and the occurrence of an accident at the time of turning on the next power is prevented, and setting and control It has a remarkable effect when used in an electric circuit which always needs to start from an initial value.

[Brief description of the drawings]

FIG. 1 is a cutaway front view of one embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a power supply circuit diagram of the motor.

[Explanation of symbols]

 2 Variable resistor main body 3 Rotary shaft 4 Knob 10 Stopper 12 Projection 13 Spring

Claims (1)

[Claims] 1. A rotary shaft for varying a resistance value in a variable resistor main body by rotation, a knob fixed to the rotary shaft, a protrusion fixed to the knob, and a stopper provided on the main body side. And a spring having one end fixed to the knob, the other end fixed to the main body side, and a spring for bringing the protrusion into contact with the stopper to return the knob to an initial position. Resistor.