JPS6132923A - Digital switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a digital switch used as a repeating switch for various numerical controls, and in particular to its contact mechanism.

(b) Prior art and its problems Conventionally, the contact mechanism of this type of switch is, for example,
It has been proposed that a printed circuit board with printed wiring is provided on one side of the character wheel, and an output signal is taken out through a movable contactor having a sliding contact portion formed by press working to slide on the printed circuit board.

However, it is difficult to manufacture the printed circuit board that is attached to the character wheel with high dimensional accuracy, so it is difficult to obtain accurate operating characteristics, and it is difficult to accurately position the printed circuit board, which is a separate piece, at the correct position. Since it was not easy, the assembly work was time-consuming.

Moreover, special materials are used to manufacture printed circuit boards.

Since it requires manufacturing equipment, it has the disadvantage of high manufacturing cost.

(c) Purpose of the Invention The purpose of the present invention has been made in view of the above-mentioned drawbacks, and is to provide a digital switch that has good operating characteristics, is easy to manufacture, and has a low-cost contact mechanism. .

(d) Structure of the invention and its effects In order to achieve the above-mentioned object, the digital switch according to the present invention is provided with a character wheel which is rotatably mounted in a case and has numbers or letters printed at equal intervals on its outer circumferential surface. The character wheel is rotated step by step through the ratchet wheel by pressing a mold wheel integrated on one side of the character wheel on the same axis and a push button portion protruding from the case. an operating axis to
In a digital switch comprising a contact unit that outputs a desired output signal by stepwise rotation of the character wheel, a cam portion corresponding to the number, etc. is provided on the other side of the character wheel on the same axis with different radii. A fixed contact and a movable contact are insert-molded in the contactor unit, and a contact portion that contacts the cam portion is insert-molded in the movable contactor.

Therefore, according to the digital switch according to the present invention, a cam portion is formed by insert molding on the side surface of the character wheel instead of the conventional printed circuit board, and a contact portion that abuts the cam portion is used instead of the conventional sliding contact portion. Since the contact portion is formed by insert molding on the movable contact, it is possible to manufacture the digital switch with higher dimensional accuracy than that of conventional printed circuit boards, and also to obtain a digital switch having accurate operating characteristics.

Moreover, since the positioning work of the printed circuit board as in the conventional example is not necessary, manufacturing is facilitated.

Furthermore, since an expensive printed circuit board is not required, it is possible to obtain a digital switch having a low-cost contact mechanism.

(E) Description of Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings of FIGS. 1 to 3.

The present embodiment generally includes a case 1, an operating shaft 10, a character wheel 20, a contact unit 30, and a case cover 40.

The case 1 is a box made of synthetic 0I resin, and has a display window 3 and an operation shaft mounting hole 4 formed on its outer operation surface 2. Furthermore,
The case 1 has a support shaft 6 protruding from the center of the bottom surface 5 for rotatably supporting a character wheel 20, which will be described later. Spring bodies 7.8 are arranged in parallel. This spring body 7
The tip of the spring body 8 is provided with a positioning pawl 7a that engages with a mold wheel 22 (described later) to restrict free rotation, while the tip of the spring body 8 comes into contact with the bottom of the operating shaft 10 to apply a return force. A convex portion 8a is provided to give the same effect.

Further, a window cover 9 made of a transparent thin plate of acrylic or the like is attached to the display window 3 for dust prevention, and the characters on the character wheel 20 can be viewed visually through the display window 3. .

Note that 1a is an engagement protrusion and 1b is an engagement hole, and when connecting multiple digital switches according to this embodiment, the engagement protrusions 1a and engagement holes 1b of adjacent switches are used to connect each other. It is designed to engage with.

The operation shaft 10 has a push button part 11 protruding from the mounting hole 4 of the case 1 at its upper end, and has a substantially U shape at its lower end.
It has a drive part 13 which is formed in a letter shape and has a drive claw 14 integrated at its free end.

When the operating shaft 10 is pushed down, the drive pawl 14 rotates the ratchet wheel 22 one pitch at a time. Note that a stopper surface 12 is formed at the base of the push button portion 11 to regulate the upper limit position.

The character wheel 20 has a disk shape with numbers or letters printed at equal pitches on an outer peripheral surface 21 by hot stamping or the like, and is rotatably mounted on the support shaft 6. On one side of the character wheel 20, a mold wheel 22 which is rotated step by step by the drive section 13 is meticulously integrally formed, and on the other side, cam portions 23a to 23d correspond to the numbers, etc. They are each formed on different concentric circles, and an annular groove 24 is provided around the circumference.

The contactor unit 30 has an outer peripheral shape that closes the case 1, and is integrally formed with an annular projection 31 that fits into the annular groove 24 of the character wheel 20 on the inner surface. A central aperture 32 is formed therein. In this central opening hole 32, a fixed contact 34 that is integrated with the common terminal 33 and movable contacts 35a-35d that abut the cam parts 23a-23d and are integrated with the terminals 36a-36d are insert-molded. It is positioned at.

The movable contacts 35a to 35d include the cam portion 23i.
Contact portions 37a-3 that contact ~23d? d is integrally molded from a synthetic resin material. As a method of forming the contact portions 37a to 37d, as shown in FIG. 4, a method of bending the movable contacts 35 and 35cl by press working may be considered, but it is difficult to obtain a predetermined dimensional accuracy. Since this is difficult, there are disadvantages in that it adversely affects operating characteristics and requires time and effort to make adjustments during assembly. However, this embodiment has the advantage that dimensional accuracy is good and adjustment work is not required.

The case cover 40 is attached to the outer surface of the contactor 22) 30 and closes the central opening 32.

Next, the operation of the digital switch having the above configuration will be explained.

First, press the push button part 11 of the operating shaft 10, and press the spring body 8.
When the operating shaft 10 is lowered against the urging force of
4 comes into contact with the teeth of the die wheel 22 and rotates the character wheel 20 which is integrated with the die wheel 22. At this time, the positioning claw 7 of the spring body 7
After a comes off as the ratchet wheel 22 rotates, it again fits between the teeth of the die wheel 22 due to its self-returning force, thereby preventing the ratchet wheel 22 from freely rotating. Therefore, the character wheel 20 rotates one pitch at a time and is stopped at that position.

Then, when the pressing force of the push button portion 11 is released, the operating shaft 10 returns due to the biasing force of the spring body 8, and the mold wheel 22
away from the teeth.

Thereafter, by repeating the same operation, the character wheel 20 rotates one pitch at a time together with the model wheel 22. Each time, the character wheel 20 rotates one pitch at a time through the transparent window cover 9 to the display window 3 to correspond to the increased amount. A number is displayed, and the cam portions 23a to 23cl corresponding to the displayed number are connected to the contact portions 37a to 37.
d and move the movable contacts 35a to 35d to the fixed contact 3.
4, an output signal corresponding to the displayed number is output.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of an embodiment of the present invention, and FIG. 2 is a front view of a contact unit of an embodiment of the present invention.
3 is a sectional view taken along the line III--III in FIG. 2, and FIG. 4 is a sectional view of a conventional contactor unit. DESCRIPTION OF SYMBOLS 1...Case, 10...Operation axis, 11...Push button part, 20...Character wheel, 21...Outer peripheral surface, 22...
- Ratchet wheel, 23a-23d... cam part, 30... contact unit, 34... fixed contact, 35a-35d.
... Movable contacts, 37a to 37d... Contact portions.

Claims (1)

[Claims] (1) A character wheel that is rotatably mounted in a case and has numbers or letters printed at equal intervals on its outer circumferential surface, and a ratchet wheel that is integrated on one side of the character wheel on the same axis; an operating shaft that rotates the character wheel step by step through the ratchet wheel by pressing a push button portion protruding outside the case; and a contactor that outputs a desired output signal by the stepwise rotation of the character wheel. In a digital switch consisting of a unit,
On the other side of the character wheel, cam portions corresponding to the numbers, etc. are provided on the same axis with different radii, and a fixed contact and a movable contact are insert-molded in the contact unit, and the A digital switch characterized in that a movable contact is insert-molded with a contact portion that contacts the cam portion.