JPS5825542Y2 - switch device - Google Patents

Description

[Detailed description of the invention] The invention consists of a pair of fixed terminals printed on a circuit board, a movable terminal that electrically bridges the pair of fixed terminals, and a movable terminal that is always connected to the fixed terminal. The present invention relates to a switch that includes a terminal and a flexible member that is held apart from the terminal.

This type of switch has a so-called switch that improves the touch of the switch by pushing the flexible member down a certain distance to the rear of the pair of fixed terminals that electrically bridges the pair of fixed terminals by pressing the flexible member. Conventionally, over-travel type devices have commonly had the movable terminal attached to the lower end surface of a sponge. It has the disadvantage that it becomes a state.

An object of the present invention is to provide a switch device that eliminates the above-mentioned conventional drawbacks, has a simple structure, and is easy to manufacture.

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 5, 1 is a key of an electronic musical instrument, 2 is an actuator provided at the lower end of the center of the key 1 and has a groove on its lower end surface, and 3 is a frame with an upper part at the rear of the actuator. The key 1 is swingably supported by a projecting piece 3a provided toward the key 1.

4 is a shelf board of an electronic musical instrument on which frame 3 is placed, 5 is a key 1
A spring is stretched between the rear part of the key 1 and the rear part of the frame 3 to keep the front part of the key upward at all times, 6 is a base plate attached to the frame 3 by holding members 7, and 8 is a spring. a lower side wall 19 made of silicone rubber and having a substantially trapezoidal cross section;
It is a flexible member that is formed into a substantially dome shape and forms a part of the switch, and includes an upper side wall 18 having a substantially trapezoidal longitudinal section extending further upward from the upper end of the lower side wall 19.

Reference numeral 9 denotes a movable terminal molded into a ring shape from silicone rubber containing carbon. When the flexible member 8 is molded into a dome shape by a mold, the pre-formed movable terminal 9 is attached to the flexible member 8. It is arranged inside the joint portion of the upper and lower side walls 18 and 19.

The lower surface of the movable terminal 9 is rough, and the upper side wall 18 is thicker than the lower side wall 19.

Furthermore, since both the flexible member 8 and the movable terminal 9 are made of silicon, they are fixed together when the flexible member 8 is molded, and no separate adhesive or the like is required.

10. 11 is a through hole provided in the ceiling and lower end of the dome, respectively, in order to release the air inside the flexible member 8; 12 is a hole formed in the substrate 6 through two integrally molded flexible members 8; This is a protrusion that is attached to a sagging through hole, and the protrusion 12 is provided with a hole 12a that does not penetrate from above along its central axis.

Therefore, by placing the flexible member 8 at a position where the protrusion 12 abuts the through hole of the substrate 6, and inserting a pin or the like into the hole 12a and pushing it, the flexible member 8 can be easily attached to the substrate 6. can be retained.

13 is a thick annular reinforcing body integrally provided on the outer peripheral surface of the flexible member 8 corresponding to the movable terminal 9; 14 and 15 are a pair of semicircular arc-shaped reinforcing bodies printed on the board 6; The fixed terminal 16 is a print-wired input line that always supplies a musical tone signal to the fixed terminal 14, and 17 is a printed-wired common output line that derives a musical tone signal from the fixed terminal 15.

In the above configuration, when the key 1 is pushed down against the spring 5, the actuator 2 presses the upper part of the flexible member 8, the thin lower side wall 19 first flexes, and the movable terminal 9 is connected to the pair of fixed terminals. 14.15 electrically bridged.

The musical tone signal supplied to the fixed terminal 14 is then transmitted to the fixed terminal 15, and then supplied to the subsequent speaker via the common output line 17.

If the actuator 2 is further pushed down in this state,
The upper side wall 18 of the flexible member 8 flexes.

At this time, since the lower end surface of the actuator 2 is provided with a groove, the through hole 10 is not blocked, and the air in the dome of the flexible member 8 freely enters and exits through the through holes 10 and 11.

Note that the annular reinforcing body 13 has a function of lowering the movable terminal 9 perpendicularly to the substrate 6.

When the key 1 is released from being depressed, the flexible member 8 returns to its original state due to its own elasticity.

As described in detail above, in this embodiment, a ring-shaped movable terminal 9 is provided inside the joint portion of the upper and lower side walls 18 and 19 of the flexible member 8, which is a simple structure. The side wall 19 of the movable terminal 9 is bent and the movable terminal 9 is connected to the pair of fixed terminals 14.
By bending the upper side wall 18 at the rear part that comes into contact with the switch 15, the touch of the switch is improved.

This so-called overtravel function is especially indispensable for switch devices for keyboard instruments.

In addition, in this embodiment, the movable terminal 9 is not shaped like a flat plate but is shaped like a ring. No split mold is required for the arrangement, and since silicon is used as the material for both the flexible member 8 and the movable terminal 9, both are fixed by heat when the flexible member 8 is molded. Therefore, no separate adhesive is required.

Furthermore, since the pair of fixed terminals 14 and 15 may each have a semicircular arc shape, the ends that face each other in close proximity are small, and the amount of musical tone signal leaking to the common output line 17 through the capacitance between them is extremely small. .

Furthermore, in this embodiment, in addition to the through hole 11 at the lower end of the flexible member 8, the through hole 10 is also provided in the ceiling of the dome.
The amount of air that enters and exits through the dome is reduced, and the risk that dust on the board 6 will enter the dome as the air enters and exits, causing poor contact of the switch, is reduced accordingly.

In this embodiment, the lower side wall 19 of the flexible member 8
Although the entire structure is made thinner than the upper side wall 18, when the flexible member 8 is pressed by the actuator 2 of the key 1, the lower side wall 19 only needs to bend faster than the upper side wall 18. What is necessary is just to make at least a part of the side wall 19 thin.

As described above, in the present invention, a flexible member is configured with upper and lower side walls having a trapezoidal cross section, and a movable terminal is fixed inside the joint between the both walls, and in particular, the flexible member corresponding to the movable terminal is Since a thick annular reinforcing body is integrally formed on the outer peripheral surface of the flexible member, when the flexible member is pressed down from above, the movable terminal is evenly pressed against the fixed terminal, and the fixed terminal is electrically bridged. Moreover, since the upper side wall, which is approximately trapezoidal, is thicker than the lower sidewall, which is also approximately trapezoidal, the switch touch is also good. It is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional side view showing an embodiment of the present invention applied to an electronic musical instrument, Fig. 2 is a partially sectional view showing the switch part, and Fig. 3 is a board part thereof. FIG. 4 is a plan view of the flexible member of the present invention, and FIG. 5 is a bottom view thereof. In the figure, 6 is a substrate, 8 is a flexible member, 9 is a movable terminal, 13
is an annular reinforcement body, 14.15 is a pair of fixed terminals, 18.1
9 is a side wall.

Claims (1)

[Claims for Utility Model Registration] A pair of fixed terminals printed on a circuit board, a movable terminal that electrically bridges the pair of fixed terminals, and a movable terminal that is always separated from the pair of fixed terminals. In the switch, the flexible member includes a lower side wall having a substantially trapezoidal longitudinal section, and a substantially trapezoidal longitudinal section extending further upward from the upper end of the lower side wall. The movable terminal is arranged and fixed inside the joint portion of the upper and lower side walls, and a thick wall is provided on the outer peripheral surface of the flexible member corresponding to the movable terminal. A switch device characterized in that the annular reinforcing body is integrally projected and the upper side wall is thicker than the lower side wall.