Patent DE356572C successfully refreshed from Google Patents.
Patent US3753004A successfully refreshed from Google Patents.
US3753004A
Expired / Lapsed
US
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Electric typewriter automatic on-off switch
Assignee: CUSTOM ELECTRONIC DEVICES Inc
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Filing: 1971-06-16
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Granted: 1973-08-14
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Expires: 1991-06-16
Abstract
Abstract An Inertia Sensor with an oscillatory reed connectible upon actuation to reed protection circuitry, timing circuitry, AC switch circuitry, and power supply circuitry for turning on an electric typewriter upon actuation of the spacer bar and automatically turning off the typewriter after a predetermined time delay. Another embodiment discloses an impact sensor utilizing a vibration sensitive reed having a magnet thereon movable within a coil for creating an electromotive force for producing a signal which is amplified by amplifier circuitry, detected, and utilized to actuate timing circuitry and an on-off switch which is connected to a power supply.
Inventors
- 👤 P Dominic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:50
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/14; H01H35/144; B; B41; B41J; B41J29/00; B41J29/38; B41J29/387
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
196 words
An electric keyboard office machine having at least one pressable keyboard element and having means for automatically turning the power to the machine on concurrently with the operation of the keyboard element and for automatically turning said power off after a predetermined time delay, said means being connected between said at least one pressable keyboard element and the machine circuitry and comprising sensing means connected to said pressable keyboard element for sensing movement of said element when pressed, electrical timing means responsive to said sensing means for producing an electrical signal of predetermined duration at the output of said electrical timing means, and switch means connected to said electrical timing means output, said machine circuitry, and adapted to be connected to the source of AC power to which the office machine is connected for blocking the passage of AC current prior to the existence of said electrical signal, for allowing the passage of AC current upon movement of the preSsable keyboard element and during the existence of said electrical signal, and for blocking the passage of AC current after the termination of said predetermined duration commencing from the last time said pressable keyboard element is pressed.
Claim 2
Dependent Claim
196 words
An electric keyboard office machine having at least one pressable keyboard element and having means for automatically turning the power to the machine on concurrently with the operation of the keyboard element and for automatically turning said power off after a predetermined time delay, said means being connected between said at least one pressable keyboard element and the machine circuitry and comprising sensing means connected to said pressable keyboard element for sensing movement of said element when pressed, electrical timing means responsive to said sensing means for producing an electrical signal of predetermined duration at the output of said electrical timing means, and switch means connected to said electrical timing means output, said machine circuitry, and adapted to be connected to the source of AC power to which the office machine is connected for blocking the passage of AC current prior to the existence of said electrical signal, for allowing the passage of AC current upon movement of the preSsable keyboard element and during the existence of said electrical signal, and for blocking the passage of AC current after the termination of said predetermined duration commencing from the last time said pressable keyboard element is pressed.
Claim 3
Dependent Claim
47 words
The apparatus of claim 1, wherein said sensing means includes a metallic reed fixedly secured at one end thereof and projecting means extending from the free end of said metallic reed, said reed moving the free end of said projecting means upon movement of the pressable element.
Claim 4
Dependent Claim
47 words
The apparatus of claim 2, wherein said sensing means includes second switch means securely fixed thereto for movement with the pressable element and at least partially encircling said projecting means for charging said electrical timing means upon said movement of the free end of said projecting means.
Claim 5
Dependent Claim
77 words
The apparatus of claim 3, wherein said sensing means includes a housing secured to the pressable element, said second switch means and the fixed end of said metallic reed being secured within said housing, and including inertia means located at the abutment of said projecting means and said metallic reed for preventing downward movement of said projecting means so that said projecting means makes physical contact with said second switch means as the pressable element is depressed.
Claim 6
Dependent Claim
30 words
The apparatus of claim 4, wherein said inertia means causes said projecting means to close circuit said second switch means with said metallic reed for charging said electrical timing means.
Claim 7
Dependent Claim
28 words
The apparatus of claim 5, wherein said electrical timing means includes reed protection means for preventing said reed from burning out or sticking to said second switch means.
Claim 8
Dependent Claim
60 words
The apparatus of claim 6, wherein said electrical timing means includes first chargeable means and said reed protection means includes a transistor for charging said first chargeable means upon the passage of a low current between said reed and said second switch means below the safe level of current which can flow through said reed without a burnout or sticking.
Claim 9
Dependent Claim
37 words
The apparatus of claim 7, wherein said electrical timing means includes second chargeable means and actuating means connected between said first chargeable means and said second chargeable means for charging said second chargeable means to full capacity.
Claim 10
Dependent Claim
21 words
The apparatus of claim 8, wherein said electrical timing means includes fixed timing means in parallel with said second chargeable means.
Claim 11
Dependent Claim
29 words
The apparatus of claim 6, wherein said electrical timing means includes a power supply means at least a portion of which is in parallel with said reed protection means.
Claim 12
Dependent Claim
24 words
The apparatus of claim 10, wherein said power supply means includes a resistance means in parallel with a capacitor for determining said predetermined duration.
Claim 13
Dependent Claim
13 words
The apparatus of claim 11, wherein said resistance means includes a Zener diode.
Claim 14
Dependent Claim
67 words
The apparatus of claim 1, wherein said switch means includes rectifying means connected to said electrical timing means output and blocking means connected between the machine circuitry and the AC source of power for preventing the passage of alternating current to the machine circuitry, said rectifying means providing an alternate electrical path allowing the alternating current to bypass said blocking means upon movement of the pressable element.
Claim 15
Dependent Claim
45 words
The apparatus of claim 13, wherein said switch means includes conductive means connected to said rectifying means for providing said alternate electrical path when said conductive means is not conducting and for preventing said passage of alternating current when said conductive means is conducting current.
Claim 16
Dependent Claim
30 words
The apparatus of claim 14, wherein said conductive means includes a transistor selectively applying an increased negative bias to said rectifying means whenever said signal of predetermined duration is absent.
Claim 17
Dependent Claim
70 words
The apparatus of claim 3, wherein said electrical timing means includes amplifying means and detecting means and Said sensing means feeds an electromagnetically induced signal to said amplifying means upon pressing the pressable element downward, said amplifying means amplifying said electromagnetically induced signal, said electrical timing means including capacitive means, and said detecting means saturating upon receiving said amplified signal and charging said capacitive means for determining said predetermined duration.
Claim 18
Dependent Claim
30 words
The apparatus of claim 1, including power supply means connected to said switch means and comprised of capacity multiplier means allowing the use of small size and low voltage capacitors.
References Cited (Backward Citations)
US1927761A
Cited
US2903118A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |