Patent US3898732A successfully refreshed from Google Patents.
US3898732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry shaver
Assignee: US Philips Corp
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Filing: 1974-03-13
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Granted: 1975-08-12
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Expires: 1994-03-13
Abstract
Abstract Dry-shaver provided with a vibrator-type motor suitable for connection to an electric current supply system and with control means which enable the dry-shaver to operate substantially equally satisfactorily at electric current frequencies of 50 Hz and of 60 Hz. The control means provide a frequency of motion of the armature of the vibrator-type motor which is equal to the frequency of the applied voltage, and achieve a mechanical resonant frequency of the motor which is higher than the highest of the frequencies likely to be used.
Inventors
- 👤 Erich Krainer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:26
CPC Classifications
B; B26; B26B; B26B19/00; B26B19/28; B26B19/282; B26B19/284; H; H02; H02K; H02K33/00; H02K33/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
89 words
In an electric shaver operable with an AC supply variable between 50Hz and 60Hz, and including a vibrator type electric motor having a stator with wire windings thereon, and a damped mechanical vibration system comprising an armature, spring means, and a reciprocatable cutter, said system having a normal oscillation frequency of twice the supply frequency, the improvement wherein said vibration system has a resonant frequency higher than 60 Hz, and said apparatus comprises means for establishing the oscillation frequency of the vibration system as equal to the supply frequency.
Claim 2
Dependent Claim
89 words
In an electric shaver operable with an AC supply variable between 50Hz and 60Hz, and including a vibrator type electric motor having a stator with wire windings thereon, and a damped mechanical vibration system comprising an armature, spring means, and a reciprocatable cutter, said system having a normal oscillation frequency of twice the supply frequency, the improvement wherein said vibration system has a resonant frequency higher than 60 Hz, and said apparatus comprises means for establishing the oscillation frequency of the vibration system as equal to the supply frequency.
Claim 3
Dependent Claim
17 words
Apparatus according to claim 1 wherein said means comprises a diode connected in series with said windings.
Claim 4
Dependent Claim
44 words
Apparatus according to claim 1 wherein said stator normally has a U-shape with two stems and windings on each stem, said means of the improvement comprising a third stem intermediate said two stems forming an E-shape, with windings on only the two outer stems.
Claim 5
Dependent Claim
22 words
Apparatus according to claim 1 wherein said vibration system has a resonant frequency in the range of 73 Hz to 79 Hz.
Claim 6
Dependent Claim
17 words
Apparatus according to claim 4 wherein said vibration system has a resonant frequency of approximately 76 Hz.
Claim 7
Dependent Claim
26 words
Apparatus according to claim 1 wherein amplitude variation of said vibration system is very small over a range of frequency of 50 Hz to 60 Hz.
Claim 8
Dependent Claim
33 words
Apparatus according to claim 1 wherein a plot of amplitude of said vibration system vs. frequency indicates substantially straight and slightly upward sloping line for frequencies thereof from 50 Hz to 60 Hz.
Claim 9
Dependent Claim
84 words
In an electric shaver operable with an AC supply variable between first and a higher second magnitude, and including a vibrator type electric motor having a stator with wire windings armature, spring means, and a reciprocatable cutter, said system having a normal oscillation frequency of twice the supply frequency, the improvement wherein said vibration system has a resonant frequency higher than said second magnitude, and said apparatus comprises means for establishing the oscillation frequency of the vibration system as equal to the supply frequency.
Claim 10
Dependent Claim
84 words
In an electric shaver operable with an AC supply variable between first and a higher second magnitude, and including a vibrator type electric motor having a stator with wire windings armature, spring means, and a reciprocatable cutter, said system having a normal oscillation frequency of twice the supply frequency, the improvement wherein said vibration system has a resonant frequency higher than said second magnitude, and said apparatus comprises means for establishing the oscillation frequency of the vibration system as equal to the supply frequency.
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) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |