Key switch with sliding mechanism and keyboard

• US 6,257,782 B1
• Filed: 06/18/1999
• Issued: 07/10/2001
• Est. Priority Date: 06/18/1998
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited, Fujitsu Takamisawa Component Limited
• Original Assignee: Fujitsu Limited, Fujitsu Takamisawa Component Limited
• Inventors: Maruyama, Junichi, Tanaka, Toshiaki, Hayashi, Kazutoshi, Watanabe, Goro
• Primary Examiner(s): COLILLA, DANIEL JAMES
• Application Number:
  US09/335,477
• Time in Patent Office: 753 Days
• Field of Search: 400/496, 400/491.2, 400/490, 400/491, 400/495.1, 400/495, 200/344, 200/345
• US Class Current: 400/495.1
• CPC Class Codes: H01H 2013/525 using a return spring acting perpendicular to the actuating direction
• CPC Class Codes: H01H 3/125 using a scissor mechanism as stabiliser

Abstract

A key switch comprising a base, a key top arranged above the base, a pair of link members interlocked to each other and operatively engaged with the base and the key top to support the key top above the base and direct the key top in a vertical direction, a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of the key top. Each of the link members includes a sliding portion slidably and shiftably engaged with either one of the base and the key top. At least one elastic member is disposed between at least one of the link members and either one of the base and the key top with which the sliding portion of each link member is engaged. The elastic member exerts biasing force, relative to a displacement or shifting amount of the sliding portion, onto at least one of the link members in a direction different from, e.g., substantially orthogonal to, the vertical shifting direction of the key top. Preferably, the biasing force assumes a linear relationship with the shifting amount of the sliding portion.

Claims

1. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top;

wherein said at least one elastic member is fixedly joined to said at least one of said link members and is abutted against said base.

2. The key switch of claim 1, wherein said at least one elastic member exerts biasing force assuming a linear relationship with said shifting amount of said sliding portion, onto said at least one of said link members.

3. The key switch of claim 1, wherein said at least one elastic member exerts biasing force in a direction substantially orthogonal to said vertical direction, onto said at least one of said link members.

4. The key switch of claim 1, wherein said at least one of said link members is provided with a loading portion separately from said sliding portion, said loading portion being formed at a position angularly displaced from said sliding portion about a mutually connecting point of said pair of link members, said biasing force being applied onto said loading portion.

5. The key switch of claim 4, wherein said loading portion is shifted in a motion different from said sliding portion when said sliding portion is shifted.

6. The key switch of claim 1, wherein said elastic member comprises a compression spring.

7. The key switch of claim 1, wherein said elastic member comprises a plate spring.

8. The key switch of claim 1, wherein said pair of link members are arranged to mutually intersect and are pivotably connected relative to each other at an intersection thereof, wherein a first one of said link members is engaged slidably at one end thereof with said base and rotatably at another end thereof with said key top, said sliding portion being provided on said one end of said first link member, and wherein a second one of said link members is engaged rotatably at one end thereof with said base and slidably at another end thereof with said key top, said sliding portion being provided on said other end of said second link member.

9. The key switch of claim 1, wherein said pair of link members are arranged to mutually intersect and are pivotably and slidably connected relative to each other at an intersection thereof, and wherein each of said link members is engaged slidably at one end thereof with said base and rotatably at another end thereof with said key top, said sliding portion being provided on said one end of said each link member.

10. The key switch of claim 1, wherein said pair of link members are meshed with each other at a toothed end of each of said link members, and wherein each of said link members is engaged slidably at one end thereof with said base and rotatably at another end thereof with said key top, said sliding portion being provided on said one end of said each link member, said toothed end being provided adjacent to said other end of said each link member.

11. The key switch of claim 10, wherein said pair of link members are arranged to intersect with each other.

12. The key switch of claim 1, wherein said switching mechanism comprises a membrane switch arranged in an opening formed in said base beneath said key top, and an actuating member for pushing said membrane switch to close said electric circuit when said key top goes down and is located at a predetermined position above said base.

13. The key switch of claim 12, wherein said actuating member is provided on said key top, and enters into said opening of said base to elastically push said membrane switch when said key top is located at said predetermined position.

14. The key switch of claim 12, wherein said actuating member is provided on at least one of said link members, and enters into said opening of said base to elastically push said membrane switch when said key top is located at said predetermined position.

15. The key switch of claim 14, further comprising an assist member movable between a first position where said assist member comes into engagement with said actuating member and a second position where said assist member is away from said actuating member, during a time when said key top is located at said predetermined position, and wherein said actuating member comes into engagement with said assist member to push said membrane switch.

16. The key switch of claim 12, wherein said actuating member is disposed above said membrane switch, and wherein a part of said link members enters into said opening of said base to push said actuating member when said key top is located at said predetermined position, whereby said actuating member pushes said membrane switch.

17. The key switch of claim 16, wherein said actuating member is movable between a first position where said actuating member is pushed by said part of said link members upon said key top is located at said predetermined position and a second position where said actuating member is away from said part of said link members.

18. The key switch of claim 12, wherein said membrane switch is movable between a first position where said membrane switch is pushed by said actuating member to close said electric circuit and a second position where said membrane switch is away from said actuating member to keep said electric circuit open, during a time when said key top is located at said predetermined position.

19. The key switch of claim 1, further comprises means for selectively securing said sliding portion of said at least one of said link members in relation to either one of said base and said key top with which said sliding portion is engaged, to hold said key top at a desired lowered position.

20. The key switch of claim 1, wherein said base includes a fixed base element engaged with said pair of link members and a movable base element disposed under said fixed base element in such a manner as to be movable with relation to said fixed base element.

21. The key switch of claim 20, wherein said at least one elastic member is fixedly connected to said movable base element and abutted onto said at least one of said link members.

22. The key switch of claim 20, wherein said at least one elastic member is fixedly connected to said at least one of said link members and abutted onto at least one vertical wall fixedly joined to said movable base element.

23. The key switch of claim 20, wherein said movable base element is moved in a direction generally parallel to a shifting direction of said sliding portion of said each link member.

24. The key switch of claim 20, wherein said movable base element is moved in a direction generally orthogonal to a shifting direction of said sliding portion of said each link member.

25. A keyboard comprising a plurality of key switches, each of said key switches being one defined in claim 20, wherein said movable base element of said each key switch is formed as a single large plate extending over said plurality of key switches, said single large plate being movably disposed under a plurality of fixed base elements of said key switches.

26. A keyboard comprising a plurality of key switches, each of said key switches being one defined in claim 1.

27. A key switch comprising:

a base;

a key top arranged above said base;

a guide member operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, said guide member including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

an elastic member disposed between said guide member and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said guide member in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top;

wherein said elastic member is fixedly joined to said guide member and is abutted against said base.

28. The key switch of claim 27, wherein said guide member is structured from a plurality of link members interlocked to one another, each of said link members being operatively engaged with said base and said key top and including said sliding portion, and wherein at least one of said link members is associated with at least one said elastic member.

29. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top;

wherein said at least one of said link members is provided with a loading portion separate from said sliding portion, said loading portion being formed at a position angularly displaced from said sliding portion about a mutually connecting point of said pair of link members, said biasing force being applied onto said loading portion.

30. The key switch of claim 29, wherein said loading portion is shifted in a motion different from said sliding portion when said sliding portion is shifted.

31. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top,

wherein said pair of link members are arranged to mutually intersect and are pivotably and slidably connected relative to each other at an intersection thereof, and wherein each of said link members is engaged slidably at one end thereof with said base and rotatably at another end thereof with said key top, said sliding portion being provided on said one end of said each link member.

32. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top

wherein said pair of link members are meshed with each other at a toothed end of each of said link members, and wherein each of said link members is engaged slidably at one end thereof with said base and rotatably at another end thereof with said key top, said sliding portion being provided on said one end of said each link member, said toothed end being provided adjacent to said other end of said each link member.

33. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top

wherein said pair of link members are arranged to intersect with each other at a toothed end of each of said link members, and wherein each of said link members is engaged slidably at one end thereof with said base and rotatably at another end thereof with said key top, said sliding portion being provided on said one end of said each link member, said toothed end being provided adjacent to said other end of said each link member.

34. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top, said switching mechanism comprised of

a membrane switch arranged in an opening formed in said base beneath said key top, and

an actuating member for pushing said membrane switch to close said electric circuit when said key top goes down and is located at a predetermined position above said base, said actuating member is provided on at least one of said link members, and enters into said opening of said base to elastically push said membrane switch when said key top is located at said predetermined position.

35. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction;

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top, said switching mechanism comprised of

a membrane switch arranged in an opening formed in said base beneath said key top, and

an actuating member for pushing said membrane switch to close said electric circuit when said key top goes down and is located at a predetermined position above said base, said actuating member is provided on at least one of said link members, and enters into said opening of said base to elastically push said membrane switch when said key top is located at said predetermined position; and

an assist member movable between a first position where said assist member comes into engagement with said actuating member and a second position where said assist member is away from said actuating member, during a time when said key top is located at said predetermined position, and wherein said actuating member comes into engagement with said assist member to push said membrane switch.

36. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top, said switching mechanism comprised of

a membrane switch arranged in an opening formed in said base beneath said key top, and

an actuating member, disposed above said membrane switch, for pushing said membrane switch to close said electric circuit when said key top goes down and is located at a predetermined position above said base,

wherein a part of said link members enters into said opening of said base to push said actuating member when said key top is located at said predetermined position, whereby said actuating member pushes said membrane switch.

37. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top, said switching mechanism comprised of

a membrane switch arranged in an opening formed in said base beneath said key top, and

an actuating member, for pushing said membrane switch to close said electric circuit when said key top goes down and is located at a predetermined position above said base, said actuating member disposed above said membrane switch, and movable between a first position where said actuating member is pushed by said part of said link members upon said key top is located at said predetermined position and a second position where said actuating member is away from said part of said link members,

wherein a part of said link members enters into said opening of said base to push said actuating member when said key top is located at said predetermined position, whereby said actuating member pushes said membrane switch.

38. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top;

wherein said base includes a fixed base element engaged with said pair of link members and a movable base element disposed under said fixed base element in such a manner as to be movable with relation to said fixed base element and said at least one elastic member is fixedly connected to said at least one of said link members and abutted onto at least one vertical wall fixedly joined to said moveable base element.

39. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other and operatively engaged with said base and said key top to support said key top above said base and direct said key top in a vertical direction, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top;

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction; and

a switching mechanism for selectively opening and closing an electric circuit in connection with a vertical movement of said key top

wherein said base includes a fixed base element engaged with said pair of link members and a movable base element disposed under said fixed base element in such a manner as to be movable with relation to said fixed base element, and said at least one elastic member is fixedly connected to said movable base element and abutted onto said at least one of said link members.

40. A key switch comprising:

a base;

a key top arranged above said base;

a pair of link members interlocked to each other to support said key top above said base, each of said link members including a sliding portion slidably and shiftably engaged with either one of said base and said key top; and

at least one elastic member disposed between at least one of said link members and either one of said base and said key top with which said sliding portion is engaged, to exert biasing force, relative to a shifting amount of said sliding portion, onto said at least one of said link members in a direction different from said vertical direction,

wherein said at least one elastic member is fixedly joined to said at least one of said link members and is abutted against said base.