Push button switch cover and method for manufacturing same

• US 6,388,218 B1
• Filed: 11/09/1999
• Issued: 05/14/2002
• Est. Priority Date: 12/22/1998
• Status: Expired due to Term

• Current Assignee: Shin-Etsu Polymer Company Limited (Shin-Etsu Chemical Company Limited)
• Original Assignee: Shin-Etsu Polymer Company Limited (Shin-Etsu Chemical Company Limited)
• Inventors: Sato, Hirohide, Ando, Hitoshi, Kiyosawa, Noriyoshi, Shirasawa, Takeo, Ohshima, Fumio
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): Nguyen, Nhung
• Application Number:
  US09/436,412
• Time in Patent Office: 917 Days
• Field of Search: 200/5.A, 200/341-345, 200/512-517
• US Class Current: 200/512
• CPC Class Codes: H01H 13/14 Operating parts, e.g. push-button
• CPC Class Codes: H01H 13/48 using buckling of disc springs
• CPC Class Codes: H01H 13/7006 comprising a separate movable contact element for each switch site, all other elements being integrated in layers
• CPC Class Codes: H01H 2205/002 fixed to operating part
• CPC Class Codes: H01H 2205/024 Means to facilitate positioning
• CPC Class Codes: H01H 2215/036 Metallic disc
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49105 Switch making
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base

Abstract

A push button switch cover capable of enhancing positional accuracy between a cover sheet and dish-shaped metal springs, thereby highly improving keying characteristics and reducing manufacturing cost. The cover sheet is provided on a front surface thereof with key tops and on a rear surface thereof with pressing projections in correspondence to the key tops. The dish-shaped metal springs are each bonded to a respective one of the pressing projections by an elastic adhesive section while keeping an apex of the dish-shaped metal spring abutted against a central portion of the pressing projection.

Claims

1. A push button switch cover comprising:

a cover substrate provided on a front surface thereof with at least one key top and on a rear surface thereof with at least one pressing projection in a manner to correspond to said key top; and

at least one dish-shaped metal spring arranged on said pressing projection corresponding thereto;

said dish-shaped metal spring being fixed on said pressing projection corresponding thereto through an adhesive section in a manner to be abutted at an apex thereof against a central portion of said pressing projection.

2. A push button switch cover as defined in claim 1, wherein said adhesive section comprises an elastic adhesive having an elongation of 75 to 700% in an amount of 2 to 7 mg.

3. A push button switch cover as defined in claim 2, wherein said elastic adhesive has an elongation of 75 to 250%.

4. A push button switch cover as defined in claim 2, wherein said elastic adhesive has an initial viscosity of 20 to 150 Pa·

s.

5. A push button switch cover as defined in claim 4, wherein said elastic adhesive has an initial viscosity of 30 to 100 Pa·

s.

6. A push button switch cover as defined in claim 2, wherein said elastic adhesive is constituted of 100 parts by weight of a main adhesive ingredient and 5 to 50 parts by weight of a silicone adhesive ingredient.

7. A push button switch cover as defined in claim 2, wherein said cover substrate is made of silicone rubber having a Shore A hardness of 40 to 70;

said pressing projection is integrally formed on said cover substrate; and

said elastic adhesive section has a Shore A hardness of 20 to 90.

8. A push button switch cover as defined in claim 1, wherein said pressing projection is integrally formed on said rear surface of said cover substrate;

and

said key top is integrally formed on said front surface of said cover substrate.

9. A push button switch cover as defined in claim 1, wherein said pressing projection is integrally formed on said rear surface of said cover substrate;

and

said key top is made of a resin material and bonded to said front surface of said cover substrate.

10. A push button switch cover comprising:

at least one key top;

at least one pressing projection arranged on a rear side of said key top; and

at least one dish-shaped metal spring having a dome-shaped top and arranged on said pressing projection corresponding thereto;

said dish-shaped metal spring being bonded at said dome-shaped top thereof to a central portion of said pressing projection by means of an elastic adhesive section.

11. A push button switch cover as defined in claim 10, wherein said elastic adhesive section comprises an elastic adhesive having an elongation of 75 to 700% in an amount of 2 to 7 mg.

12. A push button switch cover as defined in claim 11, wherein said elastic adhesive has an elongation of 75 to 250%.

13. A push button switch cover as defined in claim 11, wherein said elastic adhesive section comprises an elastic adhesive having an initial viscosity of 20 to 150 Pa·

s.

14. A push button switch cover as defined in claim 13, wherein said elastic adhesive has an initial viscosity of 30 to 100 Pa·

s.

15. A push button switch cover as defined in claim 11, wherein said elastic adhesive is constituted of 100 parts by weight of a main adhesive ingredient and 5 to 50 parts by weight of a silicone adhesive ingredient.

16. A push button switch cover as defined in claim 11, wherein a cover substrate made of silicone rubber having a Shore A hardness of 40 to 70 is arranged;

said pressing projection is integrally formed on said cover substrate; and

said elastic adhesive has a Shore A hardness of 20 to 90.

17. A push button switch cover as defined in claim 16, wherein said pressing projection is arranged on a rear surface of said cover substrate;

and

said key top is arranged on a front surface of said cover substrate.

18. A push button switch cover as defined in claim 16, wherein said pressing projection is integrally formed on said rear surface of said cover substrate;

and

said key top is made of a resin material and bonded to said front surface of said cover substrate.