EP0224006A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Pushbutton switches using dome springs
Assignee: Fujitsu Ltd
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Filing: 1986-10-15
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Granted: —
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Expires: 2006-10-15
Abstract
Abstract A pushbutton switch using a dome spring (11), has a bottom plate (30), a switch housing (50), a plunger (18), passing through a guide hole (51) in the housing (50), having a pressable top (17) outside the housing (50), and a switch element comprising a terminal plate (12) mounted vertically on the bottom plate (30) and having an indentation (24) in a vertical face, carrying the dome spring (11). The switch has also a spring/lever arrangement (20, 40, 401, 402, 403) comprising, in the housing (50), a coil spring (20), mounted between the plunger (18) and the end of one lever arm (402) of an L-form lever (40) such that vertically downward movement of the plunger (18), transmitted to the lever (40) via the coil spring (20), results in substantially horizontal movement of the end of the other lever arm towards the terminal plate (12), to deform the dome spring (11).
Inventors
- 👤 Kazutoshi Fujitsu Ltd. Patent Dept. Hayashi
- 👤 Hideo Fujitsu Ltd. Patent Dept. Nabetani
- 👤 Toshiaki Fujitsu Ltd. Patent Dept. Tanaka
- 👤 Kazushi Fujitsu Ltd. Patent Dept. Ishida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 22:38
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/70; H01H13/78; H01H13/807; H01H13/02; H01H13/12; H01H13/20; H01H11/00; H01H11/0056; H01H13/50; H01H2215/00; H01H2215/034; H01H2215/036; H01H2221/00; H01H2221/064; H01H2225/00; H01H2225/028; H01H2237/00; H01H2237/002; H01H5/00; H01H5/04; H01H5/30
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
136 words
A pushbutton switch comprising a dome spring, having a plunger, with a top or keytop thereon, pressable by an operator of the switch, and a spring/lever arrangement for transmitting movement of the plunger, when the top or keytop is pressed by the operator, to the dome spring, to deform the dome spring to accomplish a switching operation, wherein the spring/lever arrangement provides two lever arms, angled one to the other, such that, in response to such movement of the plunger, the end of the one lever arm is displaced substantially in the direction of movement of the plunger, resulting in displacement of the end of the other lever arm in a direction transverse to the direction of plunger movement, to deform the dome spring, which is mounted domed towards the end of the other lever arm.
Claim 2
Dependent Claim
136 words
A pushbutton switch comprising a dome spring, having a plunger, with a top or keytop thereon, pressable by an operator of the switch, and a spring/lever arrangement for transmitting movement of the plunger, when the top or keytop is pressed by the operator, to the dome spring, to deform the dome spring to accomplish a switching operation, wherein the spring/lever arrangement provides two lever arms, angled one to the other, such that, in response to such movement of the plunger, the end of the one lever arm is displaced substantially in the direction of movement of the plunger, resulting in displacement of the end of the other lever arm in a direction transverse to the direction of plunger movement, to deform the dome spring, which is mounted domed towards the end of the other lever arm.
Claim 3
Dependent Claim
168 words
A switch as claimed in claim 1, comprising a bottom plate, considered to lie horizontally; a switch housing, adapted to be positioned on the bottom plate and having a guide hole therein; the plunger passing through the guide hole with its top, carrying a keytop thereon, outside the housing, and moveable, when the keytop is pressed, vertically downwards towards the bottom plate; a terminal plate, mounted vertically on the bottom plate, within the housing and having an indentation in one vertical face thereof in which switch contacts are provided and in which the dome spring is carried domed away from the terminal plate; the spring/lever arrangement comprising, in the housing, a coil spring, mounted between the plunger and the end of said one lever arm, and a lever, of L-form, such that vertically downward movement of the plunger, transmitted to the lever via the coil spring, results in substantially horizontal movement of the end of said other lever arm towards the terminal plate, to deform the dome spring.
Claim 4
Dependent Claim
60 words
A switch as claimed in claim 2, wherein the pivot axis of the lever (between the two lever arms) is positioned, in the switch, so that said substantially horizontal movement of the end of said other lever arm is movement towards the plunger, said indentation being in a vertical face of the terminal plate which faces away from the plunger.
Claim 5
Dependent Claim
60 words
A switch as claimed in claim 2, wherein the pivot axis of the lever (between the two lever arms) is positioned, in the switch, so that said substantially horizontal movement of the end of said other lever arm is movement away from the plunger, said indentation being in a vertical face of the terminal plate which faces towards the plunger.
Claim 6
Dependent Claim
142 words
A switch as claimed in claim 3, wherein the lever is provided by a member generally in the form of a wedge having an aperture through the wedge from one inclined wedge surface to the other, the member carrying protruberances on the two external side surfaces of the wedge, located towards the thick end of the wedge, providing pivot points defining the pivot axis of the lever mounted in the switch, the thin end of the wedge carrying a protruberance for locating an end of the coil spring and the thick end of the wedge carrying, on an internal surface, facing into the aperture, a further protruberance for actuating the dome spring, the terminal plate being mounted in the switch so as to extend from the bottom plate through the aperture with said vertical face facing the thick end of the wedge.
Claim 7
Dependent Claim
82 words
A switch as claimed in claim 4, wherein the lever is provided by a generally T-shaped member, the upright of the T carrying at its free end a protuberance for locating an end of the coil spring, the cross-bar of the T having hooks at its ends for hooking onto protruberances provided on the terminal plate defining a pivot axis of the lever mounted in the switch, and having centrally a protuberance, offset from the pivot axis, for actuating the dome spring.
Claim 8
Dependent Claim
92 words
A switch as claimed in any of of claims 2 to 6, wherein the plunger has, at its top, a hole for receiving a support body of the keytop, there being provided within the hole upwardly directed projections for entering an internal hole provided in the support body, there being steps formed on the inside wall of the hole in the plunger arranged to cooperate with external projections provided on the support body, so that when the support body is received in the hole in the plunger it is locked in place.
Claim 9
Dependent Claim
112 words
A switch as claimed in any one of claims 2 to 7, wherein the plunger has cut-outs in its sides extending downwardly from its top surface part way towards the bottom of the plunger, the switch housing having projecting portions, at the guide hole, which enter the cut-outs, engagement of the projecting portions with the bottoms of the cut-outs defining the uppermost, rest position of the plunger; the plunger having also, in the cut-outs, deformable resilient tabs, and the switch housing being configured so that those tabs impact the housing before the bottoms of the cut-outs, the tabs then suffering deformation, to absorb shock, as the plunger returns to the rest position.
Claim 10
Dependent Claim
70 words
A switch as claimed in any one of claims 2 to 8, wherein the plunger has, extending upwardly from its bottom surface, a cut-out which the end of said one lever arm enters (in a case in which a wedge-shaped member provides the lever, the thin end of the wedge; in a case in which a T-shaped member provides the lever, the free end of the upright of the T).
Claim 11
Dependent Claim
80 words
A switch as claimed in claim 9, wherein the cut-out entered by the end of said one lever arm extends, laterally, through the plunger, retaining at the top of the cut-out at its rear, away from the lever arm entry, a rear wall portion, the end of said one lever arm entering the cut-out being sufficiently long that, with sufficient depression of the plunger, the bottom of the rear wall portion directly engages the end of said one lever arm.
Claim 12
Dependent Claim
54 words
A switch as claimed in any one of claims 2 to 10, wherein the terminal plate stands vertically on the bottom plate with lead terminals extending from the bottom of the terminal plate and fixed in holes provided in the bottom plate, the top of the terminal plate being supported by the switch housing.
Claim 13
Dependent Claim
28 words
A switch as claimed in any one of claims 2 to 10, wherein the terminal plate and bottom plate are formed as a single monobloc plastics molded body.
Claim 14
Dependent Claim
35 words
A switch as claimed in any one of claims 2 to 12, wherein the indentation in the terminal plate, carrying the dome spring, is rectangular in form, and the dome spring is rectangular in form.
Claim 15
Dependent Claim
76 words
A switch element, comprising: a terminal plate having outer and inner contacts, lead terminals and an indentation therein for carrying a dome spring; a dome spring carried in the indentation, over the inner and outer contacts, domed (convex) away from the terminal plate, electrical connection between inner and outer contacts being established by deforming the dome spring from its domed configuration; the or each inner contact being provided with a degree of elasticity (being flexibly resilient).
Claim 16
Dependent Claim
76 words
A switch element, comprising: a terminal plate having outer and inner contacts, lead terminals and an indentation therein for carrying a dome spring; a dome spring carried in the indentation, over the inner and outer contacts, domed (convex) away from the terminal plate, electrical connection between inner and outer contacts being established by deforming the dome spring from its domed configuration; the or each inner contact being provided with a degree of elasticity (being flexibly resilient).
Claim 17
Dependent Claim
25 words
A switch element as claimed in claim 14, wherein the or each inner contact is provided by a protruding portion of a meander-form metal frame.
Claim 18
Dependent Claim
49 words
A switch element as claimed in claim 15, wherein the terminal plate comprises a base plate member with the indentation therein, a first metal frame providing the or each inner contact, an insulating film, having an opening therein, and a second metal frame providing the or each outer contact.
Claim 19
Dependent Claim
50 words
A switch element as claimed in claim 13, 14, 15 or 16, wherein inner and outer contacts, lead terminals and interconnecting wiring parts between contacts and lead terminals are formed from continuous sheet material by a punching-out process, and the terminal plate is formed by subsequent molding and cutting-off processes.
Claim 20
Dependent Claim
26 words
A switch as claimed in any one of claims 1 to 13, employing a switch element as claimed in any one of claims 14 to 17.
Claim 21
Dependent Claim
28 words
A pushbutton switch, or a switch element, as the case may be, substantially as hereinbefore described with reference to any of Figs. 5 to 24 of the drawings.
Claim 22
Dependent Claim
28 words
A pushbutton switch, or a switch element, as the case may be, substantially as hereinbefore described with reference to any of Figs. 5 to 24 of the drawings.
References Cited (Backward Citations)
EP0003473A1
Cited
US4412113A
Cited
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