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US5456541A Expired / Lapsed US ⏱️ 0.0 years remaining

Key unit of a keyboard

Assignee: Individual
•
Filing: 1994-03-23
•
Granted: 1995-10-10
•
Expires: 2014-03-23
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Abstract

Abstract An improved key unit of a keyboard comprising a key top, a keyboard plate and a conductive film; the conductive film being mounted beneath the keyboard plate; the keyboard plate has a mounting base comprising a hollow cylinder mounted thereon and the key top being mounted on the mounting base through the hollow cylinder. The key unit further comprises: (1) a lower portion of the key top having a stem extending therefrom; the stem having a blind hole therein and two symmetrical sides, the stem also having two salient blocks mounted on the two symmetrical sides; the mounting base having a mounting socket comprising two symmetrical guide grooves therein; beneath the two guide grooves, the mounting socket further comprising two stop-and-guide grooves being furnished and aligned to the guide grooves, but being slightly deeper than the two guide grooves, respectively; (2) a bottom portion of the stop-and-guide grooves in the mounting socket having a bias flange; and (3) a taper-shaped spring supported on the bias flange which is mounted between the stem and the mounting socket so as to retain the key unit in the stop-and-guide grooves.

Inventors

  • 👤 Liao Ching-Shui

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 15:07
CPC Classifications
B; B41; B41J; B41J5/00; B41J5/08; B41J5/12; H; H01; H01H; H01H13/00; H01H13/70; H01H13/702; H01H13/705; H01H2215/00; H01H2215/03; H01H2221/00; H01H2221/024; H01H2221/026; H01H2235/00; H01H2235/01; H01H2235/016; H01H2235/022; H01H2235/026

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 183 words
An improved key unit of a keyboard comprising a key top, a keyboard plate and a conductive film; said conductive film being mounted beneath said keyboard plate; said keyboard plate having a mounting base comprising a hollow cylinder mounted thereon; said key top being mounted on said mounting base through said hollow cylinder; said key unit further comprising: a lower portion of said key top having a stem extending therefrom; said stem having a blind hole therein and two symmetrical sides, said stem also having two salient blocks mounted on said two symmetrical sides; said mounting base having a mounting socket comprising two symmetrical guide grooves therein; beneath said two guide grooves, said mounting socket further comprising two stop-and-guide grooves being furnished and aligned to said guide grooves, but being slightly deeper than said two guide grooves respectively; a bottom portion of said stop-and-guide grooves in said mounting socket having a bias flange; and a taper-shaped spring supported on said bias flange which is mounted between said stem and said mounting socket so as to retain said key unit in said stop-and-guide grooves.
Claim 2
Dependent Claim 183 words
An improved key unit of a keyboard comprising a key top, a keyboard plate and a conductive film; said conductive film being mounted beneath said keyboard plate; said keyboard plate having a mounting base comprising a hollow cylinder mounted thereon; said key top being mounted on said mounting base through said hollow cylinder; said key unit further comprising: a lower portion of said key top having a stem extending therefrom; said stem having a blind hole therein and two symmetrical sides, said stem also having two salient blocks mounted on said two symmetrical sides; said mounting base having a mounting socket comprising two symmetrical guide grooves therein; beneath said two guide grooves, said mounting socket further comprising two stop-and-guide grooves being furnished and aligned to said guide grooves, but being slightly deeper than said two guide grooves respectively; a bottom portion of said stop-and-guide grooves in said mounting socket having a bias flange; and a taper-shaped spring supported on said bias flange which is mounted between said stem and said mounting socket so as to retain said key unit in said stop-and-guide grooves.
Claim 3
Dependent Claim 57 words
An improved key unit as claimed in claim 1, wherein said bias flange has a taper-shaped bias hole to facilitate said taper-shaped spring, said taper-shaped bias hole having an inner surface against which said taper-shaped spring rubs when a load is applied thereto, said rubbing of said taper-shaped spring against said taper-shaped bias hole generates a sound.
Claim 4
Dependent Claim 24 words
An improved key unit of a keyboard as claimed in claim 2, wherein said taper-shaped bias hole in said bias is a round hole.
Claim 5
Dependent Claim 32 words
An improved key unit of a keyboard as claimed in claim 1, wherein both sides of said salient blocks mounted on said two symmetrical sides of said stem have two slits, respectively.

References Cited (Backward Citations)

DE272631C Cited
US4859820A Cited
US4939324A Cited
US5120923A Cited
US5203448A Cited
US5215187A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-10-09 1999-04-10 1999-10-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-10-09 2003-04-10 2003-10-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-10-09 2007-04-10 2007-10-10 $7700.00 Window Closed / Lapsed

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