JPS6068513A - 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 the Invention This invention relates to a timer, a video player (V
Regarding digital switches used for recording time setting etc. in TR), ZARANI IT SH< has a character wheel with numbers or letters printed on the outer circumference built into the case, and the character wheel can be rotated to select the desired number or character. As the characters are displayed through the case window, the displayed digits are associated with a digital switch that extracts the characters as a BCD code signal.

(B) Background of the Invention This type of digital switch is manufactured separately from the character wheel on the side of the character wheel in order to convert the numbers or characters displayed through the case window into 13CD code signals and take them out. Paste the pudding 1 board that has been installed, and keep the contact of this pudding 1-curtain in constant contact with the contact of the output terminal, and connect this common terminal contact to the numbers J and letters displayed above. Output j terminal contact and pudding 1
- Short-circuiting is attempted through the S-electrode pattern on the board, but it has the following drawbacks.

・Since the letter wheel and pudding 1~board are manufactured separately,
The number of parts is large, the number of assembly steps increases, and the cost becomes high.

- Since the printed circuit board must be correctly positioned and attached to the character wheel, highly accurate manual work is required and the process is complicated, and it is difficult to provide a reliable switch due to misalignment between the two.

・As it is a combination of separate parts such as the character wheel, print 1 and the board, the tolerance of the conductive pattern of the printed board,
Eccentricity with respect to the character wheel is added, and the positional accuracy with respect to the contact point decreases, and the reliability of the switch function is also lacking.

・The conductive pattern part of the printed circuit board and the character wheel rotation operation part (6 parts such as the finger-operated radiet wheel claws and buttons)
14i4) are close to each other, electrostatic discharge from the human body is likely to occur, and there is a risk that electronic circuits including subsequent semiconductors may be destroyed.

(C) Purpose of the Invention This invention eliminates the use of a board as a separate member having a conductive pattern such as the printed circuit board, and converts a desired number or character into a digital signal using only a character wheel and a group of contacts as a single member. The purpose is to provide a digital switch that can be extracted by

(D) Summary of the Invention This invention has a method in which a group of cams corresponding to each number or letter are integrally formed on the side surface of a character wheel, and these cams are arranged concentrically at different positions from the axis of the character wheel. The digital switch is characterized in that a group of contacts for output terminals which are selectively turned on or off by these cams are provided facing the side surface of the character wheel.

(E) Effects of the Invention According to this invention, the member that turns on and off the contacts for extracting digital signals is a cam, and since this cam is integrally molded on the side surface of the character wheel, the character wheel is a single unit. Digital signals can be taken out using these members, eliminating the need for a printed circuit board as a separate member as in the past. Therefore, - The number of parts of the switch is small, and assembly is easy, making it possible to significantly reduce costs.

- The correspondence between numbers or letters and the cam is automatically determined when forming the letter wheel, so the alignment between the two is accurate.
We can provide reliable switches.

·Pudding!・By eliminating the board, it is possible to prevent electrostatic discharge from the human body and damage to electronic circuits including semiconductors.

- In conventional digital switches, the contacts are always in contact with the printed circuit board, which shortens the life of the switch due to contact stress, but with the cam system of this invention, the numbers displayed through the case window Alternatively, since only the contact points of the letters are displaced by contact with the cam, the life can be extended.

Embodiment of the Invention Hereinafter, an embodiment of the invention will be described in detail based on the drawings.

FIG. 1 shows an exploded view of the digital switch. One side of the synthetic resin case 1 is open, and a character wheel 2, which will be described later, is inserted into this part, and it is closed with contact units 1 to 3. ing. In addition, there is a display window 1 on the circumference of case 1.
a and a fitting opening 1b for the switch operation shaft 4 are opened, and a transparent window plate 5 manufactured by pressing a transparent plate such as an acrylic plate is attached to the display window 1a. 1C is an engagement protrusion, and 1d is an engagement hole. When multiple switches are connected, adjacent switches are mutually engaged and covered using the engagement protrusion 'IC' and the engagement hole 1d.

Inside the case 1 is a support shaft 1 that rotatably supports the character wheel 2.
e is provided in a protruding manner, and resin springs 6 and 7 are provided above and below the supporting shaft portion 1 (!), and approximately triangular convex portions 6a are provided at the tips of these resin springs 6 and 7.

7a is formed. These structures are particularly noticeable at d5 in FIG.

The switch operation shaft 4 fitted in the opening 1b is located on the right side of the push button 4a that projects outward from the opening 1b, and the shaft 4b that protrudes into the case 1 is approximately (J-shaped) bent. A substantially triangular drive pawl 4C is provided at the free end.

First, to explain the stepping motion of the switch operating shaft 4 as shown in the letter 2, as shown in FIG. , the convex portion 6a of the resin spring 6 on the upper side engages with the tooth claw portion of the ratchet wheel 8 on the character wheel 4, thereby preventing the character wheel 2 from freely rotating.

From this state, use the push button 4a to move the switch operating shaft 4 to the resin spring 7.
When pressed down against
Avoid rotating one pitch. Due to this rotation, the convex part 6a of the resin spring 6 is removed from the -H wedge wheel 8, and then falls into the adjacent toothed part.Next, by removing the finger from the push button 4a, the switch operating shaft 4 is released from the resin spring 7. The movement of the character wheel 2 is automatically reversed, and the one-pitch rotation of the character wheel 2 (movement of the character wheel for one digit or one character) is controlled.

The character wheel 2 is molded from synthetic resin, and numbers or letters are printed on the outer circumferential surface by hot stamping or the like at equal intervals, the ratchets 1 to 8 described above are integrally molded on the - side, and the other side is Cams 9a to 9d as shown in FIG. 6 are also integrally molded.

The cams 9a to 9d are arranged concentrically at different radial positions with respect to the center of the character wheel 2, and the cam 9d on the center side goes to the pin 1 of ■, the cam 9C goes to the bit of ■, and the cam 9b goes to the bit of ■. 9a is the cam corresponding to the pitches 1 to 1 of ■.The part 1 shown by hatching in the figure is a flat part that protrudes from the side of the character wheel, and both ends of this flat part are flush with the side of the character wheel through smooth tapered surfaces. It has become.

These cams 98 to 9d are for on/off control of contact JAY, which will be described next. That is, as shown in FIGS. 7 and 8, the contact unit 3 connects the through terminal 10 and the protruding horn terminals 11a to 11d to 0, which are held in the resin body 3a, and are connected to external terminals. Parts 12a to 12e
are drawn out at equal pitches and on the same plane. Among the output terminals, 11a is the output terminal for ■Pip] corresponding to cam 9a, 11b is the output terminal for ■Bit corresponding to cam 9C, IIC is the output terminal for ■Pip 1~ corresponding to cam 9b, and 11d is the output terminal for ■Pip1~ corresponding to cam 9b. ■ At the output terminals of pins 1 to 1 corresponding to the cam 9b, the fixed contact portion 10 integrated with the common terminal 10 overlaps the movable contacts 138 to 13d of the output terminals 11a to 11d, and receives the entirety of the movable contacts 138 to 13d. These movable contacts 1
38 to 13d are brought into and out of contact with the fixed contact portion 10a by the movement of the cams 9a to 9d, and the BCD code corresponding to the number or character displayed from the display window 1a is read.

For example, to explain the position shown in Fig. 6, cam 9a
The state fl in which the movable contacts 13a to 13d come into contact with the fixed contact part 10 by the convex portion of ~9d is as shown in the table below (and the output is
3″ comes out.

The same can be said for other positions.

In the digital switch having the above configuration, the switch operating shaft 4 and the character wheel 2 are fitted into the case 1, and the contactor unit (-3) is placed opposite the cam surface of the character wheel 2. 1 is closed with this contactor unit 3, and a sealing tape (which may be a film or a press-molded product) 14 is adhesively fixed to the contactor unit 3.

In this way, as the push button 4a is pressed down with a finger, the character wheel 2 advances one pitch at a time, and different numbers or characters are sequentially displayed from the display window 1a, and the movable contacts 138-13d are changed to fixed contacts by the cams 9a-9d. The BCD code signal corresponding to the displayed number or character is output.

Therefore, the presence of a conventional printed circuit board is unnecessary.The movable contact pieces 13ε1 to 13d are directly on/off controlled by the character wheel 2 as a single member C1, and the above-mentioned B CD ]-do signal is taken out.

[Brief explanation of drawings]

The drawings show one embodiment of the invention, and FIG. 1 is an exploded perspective view of a digital switch. FIG. 2 is a longitudinal cross-sectional side view of the switch d51 in the assembled-C state. FIG. 3 is a cutaway front view of the main parts of the switch. Figure 1 is a sectional view of the ratchet mechanism. Figure 5 is a half-sectional view of the character wheel. Figure 6 is also a front view of the cam surface side of the 51 character wheel. FIG. 7 is a front view of the seal plate. FIG. 8 is a sectional view of the seal plate. 1... Cous 1a... Rise window (display window) 2... In the text 9a, 9d... Cam 13a, 13
(1... OJ moving contact Fig. 2 4 / Fig. 3 a Fig. 4 7a 7 Fig. 5 Fig. 6

Claims (1)

[Scope of Claims] 1. A character wheel with numbers or letters printed on the outer peripheral surface is built into the case, and by rotating this character wheel, a desired number or letter can be displayed through the case window. Iζ is a switch for extracting characters as digital signals, and a group of cams corresponding to each number or letter are integrally formed on the side of the character wheel, and these cams are connected to the axis of the character wheel. The position is different from
A group of movable contacts for the output terminals, which are selectively turned on and off by these cams, are placed facing the side of the dial wheel.