# US 6,297,809 B1 · Keyboard apparatus free from incorrect fitting of key-top in type and fitting direction thereof

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- Number: US 6,297,809 B1
- Document ID: US6297809B1
- Status: Granted
- Kind: B1
- Application number: 09/408,332
- Filed: 1999-09-29
- Granted: 2001-10-02
- Earliest claimed: 1998-09-30
- Assignees: Alps Electric Co., Ltd.
- Inventors: Hideki Ito
- Web page: https://patentgrep.com/patent/US6297809B1

## CPC

- H01H 13/705: characterised by construction, mounting or arrangement of operating parts, e.g. push-buttons or keys
- H01H 2221/034: Coded keys
- H01H 2300/044: Application rejection 1: coded interacting surfaces, polarising, e.g. to avoid insertion of a circuit breaker or fuse or relay or rating plug of the wrong caliber or in the wrong direction
- H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00)

## Abstract

When plural types of key-switch bodies arranged on a keyboard base are fitted with the corresponding types of key-tops, fitting of an incorrect key-top on a key-switch is avoided. Each key-top has a key-top side assortment cord comprising a unique combination of convex portions and concave portions which is determined by the type thereof, and a housing of each key-switch body has a body side assortment cord comprising a unique combination of convex portions and concave portions engageable with the key-top side assortment cord in pairs. The key-tops can be fitted to the key-switch bodies only when the key-top side assortment cord is brought into engagement with the body side assortment cord.

## Claims

### Claim 1

A keyboard apparatus comprising:
a keyboard base;
key-switch bodies arranged on said keyboard base; and
key-tops corresponding to said key-switch bodies, each of said key-tops including a key-top side assortment cord having a first unique combination of convex portions and concave portions which is determined by a type of key-top thereof, and each of said key-switch bodies including a body side assortment cord having a second unique combination of convex portions and concave portions engageable with the key-top side assortment cord,
wherein said key-tops are fittable to said key-switch bodies only when the key-top side assortment cord is brought into engagement with the body side assortment cord, the key-top side assortment cord is formed below a portion of a side wall of each of said key-tops, and the body side assortment cord is formed above a housing of each of said key-switch bodies.

### Claim 2

A keyboard apparatus comprising:
a keyboard base;
key-switch bodies arranged on said keyboard base; and
key-tops corresponding to said key-switch bodies, each of said key-tops including a key-top side assortment cord having a first unique combination of convex portions and concave portions which is determined by a type of key-top thereof, and each of said key-switch bodies including a body side assortment cord having a second unique combination of convex portions and concave portions engageable wit the key-top side assortment cord,
wherein said key-tops are fittable to said key-switch bodies only when the key-top side assortment cord is brought into engagement with the body side assortment cord, each of said key-tops further comprises a key-top side direction cord to define a fitting direction disposed in a different position from that of the key-top side assortment cord having one of a convex portion and a concave portion, and each of said key-switch bodies further comprises a body side direction cord disposed in an engaging position with the key-top side direction cord having one of a convex portion and a concave portion, and wherein said key-tops are fittable to said key-switch bodies only when the key-top side direction cord is brought into engagement with the body side direction cord.

### Claim 3 (depends on 2)

A keyboard apparatus according to claim 2, wherein the key-top side direction cord is formed in one of a foreground position of said keyboard base and a bask position thereof.