EP0543649A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Keyswitch assembly
Assignee: Brother Industries Ltd
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Filing: 1992-11-19
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Granted: —
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Expires: 2012-11-19
Abstract
Abstract The present invention provides a keyswitch assembly enabling a keyboard employing the same to be formed in a small thickness without sacrificing the stroke of the key to the reduction of thickness of the keyboard, facilitating keystroke operation and securing, reliable keystroke. The keyswitch assembly has a key (1) supported on a base plate (25) by a support mechanism formed by pivotally connecting first and second support levers (7, 8), each provided with pivots at their opposite ends, in a scissors-like form with a pivotal joint (A). The support levers are connected to the key and the base plate by fitting the pivots thereof in round holes (4) and horizontally elongate grooves (5) formed in the key and in round holes (29) and horizontally elongate grooves (28) formed in the base plate. When the key is depressed, the first and second support levers turn on the pivots fitted pivotally in the round holes and the pivotal joint compresses a rubber spring (31) disposed under the support mechanism for switching.
Inventors
- 👤 Isao c/o Brother Kogyo K.K. Mochizuki
- 👤 Takeyuki c/o Brother Kogyo K.K. Takagi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:13
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/02; H01H13/12; H01H13/20; H01H13/14; H01H3/00; H01H3/02; H01H3/12; H01H3/122; H01H3/125
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
51 words
A keyswitch assembly comprising: a key; a base plate disposed beneath said key; key support means for supporting said key for vertical movement with respect to said base plate, said key support means being pivotally coupled to said key and said base plate; and a switching member disposed under said key.
Claim 2
Dependent Claim
73 words
The key switch assembly according to claim 1, wherein said key support means comprises first and second levers pivotally joined and forming a scissors-type mechanism with a pivot axis, said first lever having a first end pivotally connected to said key and a second end slidably connected to said base plate, said second lever having a first end slidably connected to said key and a second end pivotally connected to said base plate.
Claim 3
Dependent Claim
42 words
The key switch assembly according to claim 2, wherein said switching member is positioned between said base plate and said key support means, such that upon depression of said key said key support means bears on said switching member to actuate switching.
Claim 4
Dependent Claim
15 words
The keyswitch assembly according to claim 3, wherein said switching member is a rubber spring.
Claim 5
Dependent Claim
71 words
The keyswitch assembly according to claim 3 or claim 4, wherein said switching member includes an inverted truncated cone having a base flange, a flexible conical side wall and a top wall with an upper and a lower surface, said side wall being arranged to buckle when said key support means bears on said upper surface and wherein an electrical contact is disposed on said lower surface within said switching member.
Claim 6
Dependent Claim
29 words
The keyswitch assembly according to any of claims 3 to 5, wherein said first and second levers delineate a downwardly concave space in which said switching member is disposed.
Claim 7
Dependent Claim
58 words
The keyswitch assembly according to any of claims 3 to 6, wherein each of said levers has an upper arm, a lower arm and a body, said upper arm and said lower . arm extending generally perpendicularly from said body, and a pair of opposed pivots extending from each end of said upper arm and said lower arm.
Claim 8
Dependent Claim
34 words
The keyswitch assembly according to any of claims 3 to 7, wherein said key support means includes a bearing surface located in the region of said pivot axis for bearing on said switching member.
Claim 9
Dependent Claim
13 words
The keyswitch assembly according to claim 8, wherein said bearing surface is semi-circular.
Claim 10
Dependent Claim
34 words
The keyswitch assembly according to claim 8, wherein said bearing surface includes two surfaces disposed at an obtuse angle on each said first and second levers, said angle being aligned with said pivot axis.
Claim 11
Dependent Claim
20 words
The keyswitch assembly according to claim 8, wherein each lever has a polygonal body to act as the bearing surface.
Claim 12
Dependent Claim
17 words
The keyswitch assembly according to claim 8, wherein said bearing surface has at least two obtuse angles.
Claim 13
Dependent Claim
39 words
The keyswitch assembly according to any of claims 3 to 12, wherein said first lever has a shaft extending laterally therefrom and said second lever has a hole extending laterally therethrough, said shaft being rotatably mounted in said hole.
Claim 14
Dependent Claim
40 words
The keyswitch assembly according to any of claims 2 to 13, wherein said second end of said first lever and said first end of second lever are arranged to slide longitudinally with respect to said key and said base plate.
Claim 15
Dependent Claim
55 words
The keyswitch assembly according to claim 14, said first end of said first lever, said second end of said first lever and said second end of said second lever are equally spaced from said pivot axis, and said first end of said first lever and said second end of said second lever are longitudinally immovable.
Claim 16
Dependent Claim
116 words
The keyswitch assembly according to claim 15, wherein said first end of said first lever has a pair of opposed ends aligned along a first line connecting said pair of ends, said second end of said first lever has a pair of opposed ends aligned along a second line connecting said pair of ends, and said second end of said second lever has a pair of opposed ends aligned along a third line connecting said pair of ends, wherein a shortest distance between said first line and said pivot axis, a shortest distance between said second line and said pivot axis and a shortest distance between said third line and said pivot axis are the same.
Claim 17
Dependent Claim
52 words
The keyswitch assembly according to claim 15, wherein said first end of said second lever is the same distance from said pivot axis as said second end of said first lever, and said lower surface of said key is arranged to remain horizontal with respect to the vertical movement of said key.
Claim 18
Dependent Claim
57 words
The keyswitch assembly according to claim 17, wherein said first end of said second lever has a pair of opposed ends aligned along a fourth line connecting said pair of ends, wherein a shortest distance between said fourth line and said pivot axis is the same as the,shortest distance between said second line and said pivot axis.
Claim 19
Dependent Claim
66 words
The keyswitch assembly according to claim 15, wherein said first end of said second lever is spaced an unequal distance from said pivot axis compared to the distance between said second end of said first lever and said pivot axis, and said lower surface of said key is arranged to remain parallel to an original position of said lower surface during vertical movement of said key.
Claim 20
Dependent Claim
27 words
The keyswitch assembly according to any of claims 15 to 17, wherein said first and second levers have lateral stop surfaces and said key is laterally immovable.
Claim 21
Dependent Claim
49 words
The keyswitch assembly according to any of claims 2 to 20 comprising a vertical axis extending from said key to said base plate, wherein said first end of said first lever and said second end of said second lever are aligned along a plane parallel to said vertical axis.
Claim 22
Dependent Claim
49 words
The keyswitch assembly according to any of claims 2 to 21, comprising a vertical axis extending from said key to said base plate, wherein said second end of said first lever and said first end of said second lever are aligned along a plane parallel to said vertical axis.
Claim 23
Dependent Claim
54 words
The keyswitch assembly according to claim 1, wherein said switching member includes an electrical contact for making an electrical connection upon the vertical movement of said key and is positioned beneath said key support means, said key support means being arranged to contact and compress said switching means upon vertical movement of said key.
Claim 24
Dependent Claim
141 words
The keyswitch assembly according to claim 1, wherein the key has at least two first connecting parts; the base plate has at least two second connecting parts; and the key support means comprises a scissors-type linkage having first, second, third and fourth ends and a pivot axis, said first end being pivotally fixed to said first connecting parts, said second end being movably connected to said first connecting parts, said third end being pivotally fixed to said second connecting parts and said fourth end being movably connected to said second connecting parts, said key being adapted to be depressed vertically with respect to said base plate, wherein a distance between said first end and said pivot axis, a distance between said third end and said pivot axis and a distance between said fourth end and said pivot axis are the same.
Claim 25
Dependent Claim
24 words
The keyswitch assembly according to claim 24, wherein said first end, a point on said pivot axis and said fourth end are linearly aligned.
Claim 26
Dependent Claim
190 words
The keyswitch assembly as claimed in claim 1, wherein a lower surface of the key is provided with at least two first connecting parts; an upper surface of the base plate is disposed below the key and the base plate is provided with at least two second connecting parts positioned to correspond to the first guiding parts; the key support means comprises a pair of pivotally connected first and second levers, said first lever having a pair of upper ends pivotally coupled to one of the first connecting parts and a pair of lower ends slidingly coupled to one of the second connecting parts and said second lever having a pair of upper ends slidingly coupled to another of the first connecting parts and a pair of lower ends pivotally coupled to another of the second connecting parts for supporting the key for vertical movement with respect to the base plate, the key support means having a downwardly concave space located above the base plate; and the switching member is disposed between the key support means and the base plate within the downwardly concave space of the key support means.
Claim 27
Dependent Claim
92 words
The keyswitch assembly of claim 1, wherein the key support means comprises a first member and a second member joined and forming a scissors-type mechanism with a pivot axis, said first member having a first end connected to said key and a second end connected to said base plate, said second member having a first end connected to said key and a second end connected to said base plate, said first end of said first member and said second end of said second member being longitudinally immovable with respect to said key.
Claim 28
Dependent Claim
31 words
The keyswitch assembly according to claim 27, wherein said first end of said first member and said second end of said second member are laterally immovable with respect to said key.
Claim 29
Dependent Claim
39 words
The keyswitch assembly according to claim 27 or 28, wherein said first end of said first member, said second end of said first member and said second end of said second member are equally spaced from said pivot axis.
Claim 30
Dependent Claim
97 words
The keyswitch assembly according to any of claims 27 to 29, wherein said first end of said first member has a first pair of opposed ends, said first end of said second member has a second pair of opposed ends, said second end of said second member has a third pair of opposed ends and said second end of said first member has a fourth pair of opposed ends, and wherein said first, second, third and fourth pair of opposed ends form an area surrounded by their ends, and said switching member is positioned within said area.
References Cited (Backward Citations)
No citation records indexed.
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