US3870840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switch pushbutton-type digit keyboard switch with leaf spring contract and actuator biasing means on common conductive frame
Assignee: Italtel SpA
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Filing: 1973-10-15
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Granted: 1975-03-11
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Expires: 1993-10-15
Abstract
Abstract An array of pushbuttons, e.g., as used for digit selection in a telescommunication system, are recived in apertures of a cylindrical housing above a printed-circuit board. A metallic disk overlying that board, partly cut away in the region of the pushbuttons, is integral with a set of leaf-spring contacts respectively associated with these pushbuttons. Each contact has a relatively broad prong with an upbent extremity, bearing from below under pressure upon a lug of the associated pushbutton, and a pair of narrow parallel tongues bent down with reference to that prong and terminating in hooked extremities which engage a corresponding contact area on the printed-circuit board upon depression of the contact by the pushbutton.
Inventors
- 👤 Gianfranco Rivetta
- 👤 Egidio Marcotti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:12
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/02; H04M1/23
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
156 words
A keyboard switch for the selective closure of a multiplicity of circuits, comprising: a support; a printed-circuit board on said support having a face provided with a multiplicity of contact areas respectively included in the circuits to be selectively closed; a conductive frame on said support; a multiplicity of pushbuttons on said support spacedly overlying said face with limited mobility perpendicular thereto; and an array of resilient contact elements on said frame interposed between said board and respective pushbuttons for completing any of said circuits under the control of the associated pushbutton, each of said contact elements being provided with a fixed end and a movable end, said movable end being split into an upbent prong bearing under pressure upon the associated pushbutton and relatively downwardly bent tongue means alongside said prong normally spaced from the corresponding contact area but engageable therewith upon displacement of said prong toward said board by depression of said associated pushbutton.
Claim 2
Dependent Claim
156 words
A keyboard switch for the selective closure of a multiplicity of circuits, comprising: a support; a printed-circuit board on said support having a face provided with a multiplicity of contact areas respectively included in the circuits to be selectively closed; a conductive frame on said support; a multiplicity of pushbuttons on said support spacedly overlying said face with limited mobility perpendicular thereto; and an array of resilient contact elements on said frame interposed between said board and respective pushbuttons for completing any of said circuits under the control of the associated pushbutton, each of said contact elements being provided with a fixed end and a movable end, said movable end being split into an upbent prong bearing under pressure upon the associated pushbutton and relatively downwardly bent tongue means alongside said prong normally spaced from the corresponding contact area but engageable therewith upon displacement of said prong toward said board by depression of said associated pushbutton.
Claim 3
Dependent Claim
156 words
A keyboard switch for the selective closure of a multiplicity of circuits, comprising: a support; a printed-circuit board on said support having a face provided with a multiplicity of contact areas respectively included in the circuits to be selectively closed; a conductive frame on said support; a multiplicity of pushbuttons on said support spacedly overlying said face with limited mobility perpendicular thereto; and an array of resilient contact elements on said frame interposed between said board and respective pushbuttons for completing any of said circuits under the control of the associated pushbutton, each of said contact elements being provided with a fixed end and a movable end, said movable end being split into an upbent prong bearing under pressure upon the associated pushbutton and relatively downwardly bent tongue means alongside said prong normally spaced from the corresponding contact area but engageable therewith upon displacement of said prong toward said board by depression of said associated pushbutton.
Claim 4
Dependent Claim
156 words
A keyboard switch for the selective closure of a multiplicity of circuits, comprising: a support; a printed-circuit board on said support having a face provided with a multiplicity of contact areas respectively included in the circuits to be selectively closed; a conductive frame on said support; a multiplicity of pushbuttons on said support spacedly overlying said face with limited mobility perpendicular thereto; and an array of resilient contact elements on said frame interposed between said board and respective pushbuttons for completing any of said circuits under the control of the associated pushbutton, each of said contact elements being provided with a fixed end and a movable end, said movable end being split into an upbent prong bearing under pressure upon the associated pushbutton and relatively downwardly bent tongue means alongside said prong normally spaced from the corresponding contact area but engageable therewith upon displacement of said prong toward said board by depression of said associated pushbutton.
Claim 5
Dependent Claim
46 words
A keyboard switch as defined in claim 1 wherein said contact elements are leaf springs and said frame is a disk integral with said leaf springs overlying said board, said disk being partly cut away around said leaf springs in the region of said contact areas.
Claim 6
Dependent Claim
26 words
A keyboard switch as defined in claim 2 wherein said toNgue means comprises a plurality of parallel tongues which together are substantially narrower than said prong.
Claim 7
Dependent Claim
21 words
A keyboard switch as defined in claim 3 wherein said tongues terminate in hooked extremities pointing toward the corresponding contact area.
Claim 8
Dependent Claim
67 words
A keyboard switch as defined in claim 3 wherein said prong has an upwardly angled tip in line with said extremities, each pushbutton being provided with a lug engaging the tip of the associated prong for pressing said tip flat against said board in a fully depressed position of the pushbutton with said leaf spring curving away from said board between said tip and said fixed end.
Claim 9
Dependent Claim
54 words
A keyboard switch as defined in claim 3 wherein said leaf spring broadens from said fixed end to a transverse line intermediate its ends along which said prong and said tongues branch off the body of the leaf spring, said fixed end being in line with said prong but laterally offset from said tongues.
Claim 10
Dependent Claim
25 words
A keyboard switch as defined in claim 6 wherein said body is provided with a longitudinal slot terminating in the vicinity of said transverse line.
Claim 11
Dependent Claim
20 words
A keyboard switch as defined in claim 7 wherein said slot widens progressively in the direction toward said transverse line.
Claim 12
Dependent Claim
29 words
A keyboard switch as defined in claim 2 wherein said board and said disk are provided with coacting formations for positively aligning said leaf springs with said contact areas.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |