JPS60150514A - Method of producing character wheel in 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 is useful for setting the time of a timer, etc., setting the temperature in a thirst controller, setting the frequency of a wireless device or measuring device, or setting the address or transmission speed on the base. J3 is used as an idigital switch used for devices that perform settings digitally.
More specifically, regarding the manufacturing method of the character die 'X full character center), a character center with numbers or letters printed on the outer circumferential surface is built into the case, and the character wheel is rotated to form the desired number or character. When the characters are displayed through the Coos window, the displayed numbers or characters are taken out as a BCD code signal and the output of the 1 digital switch is Q! 13 to j
This invention relates to a method for manufacturing a character wheel of a switch in which a cD code signal can be taken out by short-circuiting the SfK pattern formed on the character wheel and a contact.

(b) Continuation of the invention This type of switch is made by positioning a conductive member on which a predetermined conductive pattern portion is printed and wired on a circular printed circuit board in the recess of the character wheel and press-fitting it one by one by hand. This naturally increases the number of parts and assembly man-hours, contributing to the high cost of the entire switch.

Therefore, the metal plate is placed close to the approximately circular conductive pattern part.
It was considered possible to eliminate the printed circuit board and reduce the number of parts and assembly man-hours by molding it integrally with the letter wheel. However, like the printed circuit board mentioned above, the metal plate is punched into individual pieces, so when insert-molding the metal plate into the character wheel, it is necessary to align each piece in the mold and check whether it is front or back. As a result, the molding speed was reduced and the dimensional variations between parts were large, making it impossible to fundamentally improve the cost.

Therefore, the inventors of the present invention created concentric conductor patterns consisting of conductive parts and insulating parts by continuously punching approximately circular metal plates from the hoop, leaving the connecting parts, and insert molding them using progressive molding. After that, negative metal plating with AuW is applied only to the exposed conductive parts using the insulating part made of this molded resin as a mask to produce a movable (rotating) contact pattern, and finally the connecting part is placed inside the outer circumferential groove. He devised and filed an application for the 7J method, which cuts and separates the concentric letter wheels for the first time.

However, with this method, a large number of high-precision parts can be produced extremely efficiently through only the series of steps of pressing → molding → cutting 1, and negative metal fittings 4- are only placed where they are needed. On the one hand, it has the advantage of being economical (and inexpensive), but on the other hand, the metal disc to be inserted is simply a metal disc with holes for resin to flow through, so it is not compatible with plating in 4'J T2. The adhesion strength (bonding force) is weak, and when rotating under the pressure of the contact, it is difficult to peel off. ■When plating is performed after molding, the plating solution stays in the gap between the mold resin and the metal disc, and this is used. There have been problems such as the risk of contact failure due to the metal sometimes coming out on the surface of the conductor.

(c) Purpose of the invention This invention eliminates the above drawbacks (■) and (■), and at the same time,
The purpose is to create a method for manufacturing character wheels that is inexpensive, highly accurate, and of high quality.

(D) Summary of Defense This invention comprises a step of plating substantially circular metal contacts on one side of a lead frame at equal pitch intervals, and a process of plating approximately circular metal contacts on one side of a lead frame, and forming a part of the circular metal contacts on the lead frame in an Iζ state. and a process of punching out a hole in a shape similar to the negative of the desired conductive pattern, a process of resin molding the circular metal contact using in-4 note molding, and after this process, the connection part with the lead frame is separated into individual pieces. The present invention is characterized in that it is a method for manufacturing a character wheel for a digital switch, which includes the step of forming a character wheel.

(E) Effects of the Invention According to this invention, metal contacts are plated on the lead frame in advance, and holes are punched into the metal contacts in a shape similar to that of the negative of the conductive pattern, so that after inser milling is completed, contact is made. Metal contact (metal plate) also for child press Ll-
"C'" is that it does not peel off, has high resistance to the letter wheels, and improves reliability.

In addition, since there is no need for plating after integral molding of the letter wheel, some of the plating liquid will not accumulate in the gaps between the resin and the gold filtration, and will not cover the gap between the resin and the gold filtration (metal plate), resulting in the risk of poor contact. There is no.

Since the conductive pattern is integrated with the character wheel, the number of parts is reduced, making it possible to lower costs.

Embodiment of the Invention Hereinafter, an embodiment of the invention will be illustrated in the drawings.

Fig. 1 is an external view of a digital switch to which this invention is applied, and Fig. 2 is an exploded view of the same (with synthetic resin case 1).
The surface is open, and a character wheel 2, which will be described later, is fitted into this portion, and the contacts 1 and 1-3 are closed.

Further, on the circumferential surface of the case 1, a display window 1a and a fitting groove 1b for the switch operation shaft 4 are provided.

The display window 18 is closed with a transparent window plate 5 made of acrylic or the like, and the numbers or letters on the character wheel 2 are displayed through this window 1a.

The switch operation shaft 4 moves the character wheel 2 one pitch at a time. : In the fitted state, press the push button 4a that protrudes outward from the lI3, and the shaft portion 4b that protrudes into the case 1 is bent into a substantially U-shape, and has a substantially triangular shape at its free end. A driving pawl 4C is provided (J is provided, and when the push button 4a is pressed down with a finger, this driving pawl 4C moves the love gills 1 to 6 integrally formed on the character wheel 2 by one pitch. In other words, the latch 11 to the mechanism are configured has been done.

The resin spring 7 shown in FIG. 2 has a ratchet 1 to pawl 7a that engage with the tooth pawl of the ratchet wheel 6 to prevent free rotation of the ratchet wheel 6, and the resin spring 8 has a pawl 7a that engages with the tooth pawl of the ratchet wheel 6 to prevent the wheel from rotating freely. It is for return use and has a convex portion 8a that comes into contact with the bottom of the shaft 4 in the upward direction.

In addition, 1G is an engagement protrusion, and 1d is an engagement hole. When connecting multiple switches, adjacent switches are mutually engaged using the engagement protrusion 1C and the engagement hole 1d. Zuru.

The character wheel 2, which has an integral ratchet wheel 6, is rotatably fitted onto the support shaft 1e of the 9-seat 1, and is molded from synthetic resin, and has a small j-stamp etc. on the outer circumferential surface. Numbers or letters 2a are printed at the same pitch intervals, the above-mentioned radii J tsu 1 to car 6 are integrally molded on the - side, and a metal plate with a conductive pattern is formed on the other side. molded. Through this integral molding, a part (concave part) where the conductive pattern part is exposed and a part (convex part) insulated with resin are formed, and the common terminal fixed to contact units 1 to 3 is connected. The output terminal side contactor fixed to the unit 3 by insert molding may be in contact with the conductive pattern at all times, and whether the contactor on the output terminal side fixed to the unit 3 by insert molding will be electrically conductive or non-conductive with the pattern as the character wheel 2 rotates. A BCD output can be obtained by combining the following.

That is, the contactor unit 13 has a common contact 10 and output terminals 11a to 11d as shown in FIGS. 3 and 4, and this is inserted into the resin base 3a, and
The external terminal portions 12a to 12e are drawn out from the resin base 3a at intervals of tq pitches and on the same plane. 3b
is the concave iM 9 d 1. which will be described later on the character wheel 2. : Pressure fit
This is a protrusion for sealing.

The digital switch with the above configuration has the switch operation 111+1e and the character wheel 2 fitted in the case 1,
Close the open part of the case 1 with the contact unit 1-3 so that it faces the conductor pattern surface of the character wheel 2, and seal tape (film or press molded product may be used). 13 as contact units 1-3
Glue and fix. In this way, when the push button 4a is pressed down with a finger, the unit 3 is activated (when 2 of the C characters is incremented by 1 non-pitch next to each other and different numbers or letters are sequentially displayed in the display window 1a). The short-circuited combination U in the pattern of four output contacts through a common contact set in 4J corresponds to this displayed number or letter over 13
0l)''-doIS is output.

The manufacturing of character 2 is carried out as follows. Figure 5 Jj, I
, and U14 in J3 in Figure 6 is t (thickness) -0.2 to 0.3.
A hoop-shaped lead frame made of copper plate, nickel silver, or 11" old copper plate with a diameter of about m/m, and an A on one side.
The members 15, such as u, are plated at equal pitch intervals (J).Next, as shown in FIG. For the circular metal contact 15, a hole i having a shape almost similar to that of the insulating part (corresponding to the negative with respect to the conductive pattern part) is formed.
6 /)) Punched out. In reality, the width of this hole is narrower than the width J of the insulation section. Next, b shows the outline of the metal contact 15 (
Connected, lead frame 14 - 1) 0) 1.1
A metal disk 17 connected to the portion 14b by a bridge portion 14a is formed. The other 14 parts 1/IC unnecessary and 41, J of C
The metal disk 17 is conveyed in a completely cantilevered state.

In step d, the bridging portion 14a is bent into a 1-shape shape. As shown in FIG. 9, this bending process takes into account the fact that the metal disk 17 is formed at a position one step lower than the outer surface of the character wheel 2. A metal disk 17 is fed into a separate mold for C molding, and is formed into a letter wheel and insert 1 by molding.

The JR electric pattern of 2 in the letter integrated in the above manner is as shown in the enlarged view of Figure 8, where 9a is the Au-plated contact part, 9c is the insulating resin part, and 9b is the letter wheel amount. The protrusion 9d on the periphery is a concave surface (the above-mentioned outer periphery fI'1) into which the protrusion 3b of the contactor unit 3 is fitted and sealed, and these are formed by the insert molding. . The outer shape of the metal disk 17 is indicated by a broken line in FIG.

The pattern layout is 'l' In the S8 diagram, the outermost circumference is C.
In the OM contact part, the arrangement is as follows: ◯ bit, ◯ filler 1~, ◯ bit, ◯◯ pip [~] inward. Correspondingly, in the contactor unit 3 shown in FIG. Corresponds to the rack.

As shown in Fig. 7, the character wheel 2 with its culm cut out is either wound into a roll in this state, or sent directly to the assembly process for the next part, and then moved to the point just before it is assembled into the case 1. 8! ′! The bridging portion 14a is cut at the portion shown by the Q-Q line in Fig. 9, that is, within the space 2M It is incorporated into case 1.

The Fumiko Oj manufactured by the manufacturing method described above satisfactorily achieves the original purpose.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an external view of an f-digital switch to which the present invention is applied. Figure 2 is an exploded view of the same. FIG. 3 is a front view of the contactor unit. FIG. 4 is a sectional view of FIG. 3. FIG. 5 is a small plan view of the arrangement of metal contacts on the lead frame. Figure 6 is a side view of the same. Figure 7 shows press processing by progressive feeding I a3J, Hink-1
- Explanatory diagram of the t-old process. FIG. 8 is an enlarged plan view of I17 after processing inks 1 to 7. FIG. 9 is a sectional view of FIG. 8. 1... Case 2... Character 14... Lead frame 15... Metal contact 16.
...hole) Fig. 1 2a Fig. 3 Fig. 4 Fig. 8 Fig. 9

Claims (1)

[Claims] 1. A character wheel with numbers or letters printed on its outer circumferential surface is rotatably built into a case, and a contact point of a conductive pattern integrated with the character wheel is short-circuited with a plurality of contacts. J: In a switch that outputs a digital signal, there is a process in which approximately circular metal contacts are plated at regular intervals on one side of the lead frame, and a process in which a part of the circular metal contacts are connected to the lead frame. A step of punching out a hole in a shape close to the negative of the external shape of this contact and a desired conductive pattern, a step of resin molding the circular metal contact using in-fog inert molding, and after about 1 step, a connecting portion of the lead frame, etc. 1. A method for manufacturing a letter in a digital switch, comprising the step of cutting out the letter to form individual pieces of letter.