JPH017942Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a keyboard switch for musical instruments used in electronic organs and the like.

FIG. 1 shows an example of a conventional keyboard switch, in which a movable contact 4 that is pushed down via an actuator 3 when the keyboard 1 is pressed down, and a fixed contact 5 that comes into contact with and separate from the movable contact 4 are provided on the underside of the keyboard 1.

Fig. 2 shows another example of a conventional keyboard switch, in which an insulating board 7 with fixed contacts 5' arranged on the underside of the keyboard 1 is arranged, and on top of this is a cylindrical actuator 3' and a movable switch made of conductive rubber. A fixed support body 6 made of a flexible material is deformed by the lowering of the cylindrical actuator 3' when the contact point 4' and the keyboard 1 are pressed down.

Both of the conventional keyboard switches shown in FIGS. 1 and 2 operate against the spring force of the keyboard spring 2, the spring force of the movable contact 4 itself, or the repulsive force of the support 6 when the keyboard 1 is pressed down. Since the movable contacts 4, 4' are configured to contact the fixed contacts 5, 5', the keyboard touch must take into account not only the keyboard spring characteristics but also the spring characteristics of the movable contact 4 and the repulsion characteristics of the support 6. The contact pressure between the fixed contacts 5, 5' and the movable contacts 4, 4' changes depending on the pressing force of the keyboard 1, so gully etc. often occur. There was a drawback of doing so.

The present invention aims to eliminate the drawbacks of the conventional keys, and includes an actuator suspended from the underside of the key, a roller-shaped conductive elastic movable contact rotatably supported by the actuator on a shaft, and a conductive elastic movable contact in the direction of key depression. The insulating substrate is provided with at least two fixed contacts substantially parallel to the key and an automatic key return means, the insulating substrate is stood upright in elastic contact with the conductive elastic movable contact, and the conductive elastic movable contact rolls as the key is pressed. The at least two fixed contacts are short-circuited by an elastic movable contact.

Next, an embodiment of the present invention shown in the drawings will be described. FIGS. 3A and 3B are a side view and a perspective view of essential parts of an embodiment of the present invention.

3'' is an actuator attached to the lower surface of the keyboard 1, and a roller-shaped movable contact 4'' made of conductive rubber rotatably supported on an insulating shaft 8 is provided at the bottom. A fixed contact 5'' for the movable contact 4'' was provided on an insulating substrate 7, and the insulating substrate 7 was stood upright in elastic contact with the movable contact 4''.

When the keyboard 1 is pressed down in this way, the roller-shaped movable contact 4'' provided on the actuator 3'' rotates on the insulating substrate 7 and descends, coming into contact with the two parallel fixed contacts 5'', 5'', and Contacts 5″, 5″ are short-circuited by movable contact 4″, fixed contacts 5″, 5″
Close the electrical circuit connected to the FIG. 4 is a front view of the main parts of another embodiment of the present invention, that is, the actuator 3'' and the movable contact 4''.

This embodiment constitutes a two-pole switch,
Two roller-shaped movable contacts 4'' supported on a shaft 8 made of insulating material were provided at the bottom of the actuator 3''.
Two sets of fixed contacts 5'' were arranged on the insulating substrate 7 to face these contacts.

The number of movable contacts 4'' and fixed contacts 5'' can be arbitrary depending on the application.

Although the movable contact 4'' is made of conductive rubber in the above embodiment, it can also be made of flexible synthetic resin mixed with conductive powder.

As described above, according to the present invention, the roller-shaped elastic movable contact is rotatable, and the movable contact is brought into contact with the fixed contact while being rotated by the movement of the actuator as the key is pressed, regardless of the position of the movable contact during the contact. The contact pressure against the fixed contact is kept constant, so there is no damage or wear on the contact, and there is no gully, etc., and there is no deflection of the movable contact due to contact with the fixed contact, unlike in conventional keyboard switches. Since there is no change, the touch on the keyboard can be determined only by the characteristics of the return spring of the keyboard without considering the spring properties of the movable contacts, and the design is easy. Unlike conventional switches, there is no need to connect lead wires to the movable contacts to connect them to the electric circuit, so the structure is simple and multi-pole contacts can be opened and closed using a single roller. There is an effect.

[Brief explanation of the drawing]

1 and 2A are side views of a conventional keyboard switch, FIG. 2B is a side view of the operating state of FIG. 2A, and FIG. 3A is a side view of an embodiment of the present invention.
FIG. 3B is a perspective view of the main part thereof, and FIG. 4 is a front view of the main part of another embodiment of the present invention. 1... Keyboard, 3, 3', 3''... Actuator, 4, 4', 4''... Elastic movable contact, 5, 5',
5″... Fixed contact, 7... Insulating board, 8... Axis.

Claims (1)

[Scope of utility model registration request] An actuator hanging from the underside of the key, a roller-shaped conductive elastic movable contact rotatably supported on the actuator by a shaft, an insulating substrate and an automatic key provided with at least two fixed contacts substantially parallel to the direction in which the key is pressed. the insulating substrate is stood upright in elastic contact with the conductive elastic movable contact, and the conductive elastic movable contact rolls as a key is pressed to short-circuit between the at least two fixed contacts. A keyboard switch for musical instruments characterized by: