JPH0373970B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of the Invention> The present invention relates to a method of manufacturing a push button switch used in a channel switch of a television receiver, a keyboard of a desk calculator, and the like.

<Prior Art and Problems> Generally, the push button of this type of switch is manufactured by resin molding without an ordinary insert. Therefore, in order to sequentially install the push buttons in each of a large number of continuously transported switch cases, it was necessary to line up the large number of push buttons using a bar feeder.

However, when the push buttons are circulated within the bar feeder, they rub against each other and tend to become electrically charged. For this reason, there was a problem in that the push button was carried out with dust attached to it, or it was attached to the push button supply guide. The adhesion of dust to the push button causes a serious drawback of poor contact in the final product, and the problem of adhesion of dust to the guide reduces the operating rate of the entire assembly machine.

<Objective of the Invention> The present invention provides a method for manufacturing a push button switch that can efficiently supply a large number of push buttons to each switch case without fear of dust adhesion, and that can improve productivity and quality. It is an object.

<Structure and Effects of the Invention> In order to achieve the above object, the present invention forms a large number of push button molding holes having cuts in a band material made of a flexible film, and inserts a synthetic resin push button into each hole. The method is characterized in that the push buttons are simultaneously molded to temporarily hold the respective push buttons in the through holes, and then the push buttons are sequentially assembled into the continuously conveyed switch case while being pushed out through the through holes of the band material. be.

With this configuration, a large number of push buttons can be handled as one through the band material, and in particular, the push buttons do not rub against each other and become electrically charged.
This prevents dust from adhering to the assembly, thereby improving the operating rate of the automatic assembly machine and providing a highly reliable push button switch. Further, according to the present invention, there is an advantage that even if the push button has directionality, the assembly work can be easily performed without requiring an alignment operation using a special bar feeder.

<Description of Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show an example of a push button switch obtained by the manufacturing method of the present invention.

In the figure, 1 is a switch case made of electrically insulating synthetic resin, 2 is a first fixed contact installed at the center of the bottom of the case 1, and 3, 3 are sandwiching the first fixed contact 2. a second fixed contact implanted at a position around the bottom of the case 1; 4, 4 is an external terminal coupled to the first fixed contact 2;
Reference numeral 5 designates external terminals connected to the second fixed contacts 3, 3, respectively. Reference numeral 6 denotes a movable contact plate which is formed into a dome shape by a conductive leaf spring or the like and can be reversely deformed, and is installed on the second fixed contacts 3, 3. Reference numeral 7 denotes a push button for inverting and deforming the movable contact plate 6, and 8 a cover fixed to the switch case 1 with a caulking pin 9 or the like to prevent the push button from coming off.

In the above configuration, when the push button 7 is pressed, the center part of the movable contact plate 6 is pushed down and comes into contact with the first fixed contact 2 in a snap action manner, thereby causing the movable contact plate 6 to pass through the movable contact plate 6 to the first between the fixed contact 2 and the second fixed contact 3, that is, the external terminal 4
A conductive state is established between and 5. When the pushing operation on the push button 7 is released, the movable contact plate 6 returns to its original shape, so that the external terminals 4 and 5 become non-conductive.

Next, a method of manufacturing the push button switch will be explained.

First, from a conductive metal strip (not shown), a third
A lead frame 10 shown in the figure is molded. This lead frame 10 has, for example, a pair of external terminal frame pieces 11 and 12 that are parallel to each other, and a pilot hole 13 for positioning.
1 and 12, a lead piece 15 for forming a first fixed contact formed on one frame piece 11, and a pair of second lead pieces 15 formed on the other frame piece 12. A plurality of sets are formed at predetermined intervals in the longitudinal direction.

Transfer the lead frame 10 to a mold,
As shown in FIG.
The switch case 1 is formed by insert molding to form the fixed contact 3. Reference numeral 17 denotes a vertical groove formed in the switch case 1 to guide the vertical movement of the push button 7.

On the other hand, the above push button 7 is manufactured as follows.

First, a band material 18 made of a flexible film such as a polyester film as shown in FIG. 5 is prepared. Push button forming through holes 19, which are slightly smaller than the neck diameter of the push button 7, are punched out at predetermined intervals p along the length of the strip 18, together with pilot holes 21 for positioning. This hole 1
9, a plurality of, for example, several, notches 20 are formed in each inner wall of the through hole 19.

Thereafter, push buttons 7 made of synthetic resin are simultaneously molded into each through hole 19 of the band material 18, as shown in FIGS. 6 and 7. In this state, each push button 7 is in a state where the inner wall of the through hole 19 is biting into the neck of the push button 7.
Since these are simultaneously molded, there is no possibility that the push button 7 will be wound up on a reed or the like, or that the push button 7 will come off from the strip 18 during transportation. Incidentally, reference numerals 21 and 21 in the figure are guided pieces formed on the push button 7 and fitted into vertical grooves 17 and 17 of the switch case 1.

The strip material 18 with the push button 7 formed in the through hole 19 is carried to an assembly process as a carrier sheet for the push button 7. In order to incorporate each push button 7 into the switch case 1 formed on the lead frame 10, the push button 7 is separated from the strip 18. This can be done by forcibly pushing out the push button 7 from the through hole 19 and fitting it into each switch case 1 that is continuously transported. In other words, if a pushing force F is applied to the push button 7 as shown in FIG.
The push button 7 is easily deformed downward as shown in the figure, and the push button 7 is removed from the through hole 19. Of course, this operation may be performed in synchronization with the transport of the switch case 1.

In this way, the push buttons 7 are formed into the strip material 18 and then released one after another, so the push buttons 7 do not rub against each other and become electrically charged, which eliminates the risk of contact failure due to adhesion of dust. With,
Automatic assembly equipment can be operated smoothly.

[Brief explanation of drawings]

1 and 2 are an exploded perspective view and a sectional view, respectively, showing an example of a push button switch obtained by the method of manufacturing a push button switch according to the present invention, and FIG.
FIG. 4 is an explanatory diagram of the manufacturing process of the switch case of the push button switch, FIGS. 5 to 7 are explanatory diagrams of the manufacturing process of the push button, and FIG. FIG. 8 is an explanatory diagram of removing the push button. 1...Switch case, 7...Push button, 18...
Band material, 19... Through hole for push button forming, 20... Notch, F... Extrusion force.

Claims (1)

[Claims] 1. Forming a large number of push button forming holes in a band made of a flexible film at predetermined intervals along the longitudinal direction of the band, and forming a plurality of cuts in the inner wall of each hole, Next, push buttons made of synthetic resin are simultaneously molded into each of the through holes and temporarily held in the holes, and each of the push buttons is placed in each of a large number of switch cases that are continuously conveyed along the longitudinal direction of the band material. A method for manufacturing a push button switch, characterized in that the push button switch is sequentially assembled while being forcibly extruded from each through hole.