US3569812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric windscreen wiper systems
Assignee: Motors Liquidation Co
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Filing: 1968-11-25
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Granted: 1971-03-09
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Expires: 1988-11-25
Abstract
Abstract In an electric windscreen wiper system, pulsed operation of the wipers is obtainable by means of a circuit, in which the electric wiper motor is intermittently connectable to an electric power source by a relaxation oscillator circuit which includes a unijunction transistor.
Inventors
- 👤 Trevor Bates
- 👤 Francis Stanley Griffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:21
CPC Classifications
B; B60; B60S; B60S1/00; B60S1/02; B60S1/04; B60S1/06; B60S1/08; B60S1/0803; B60S1/0807
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
214 words
A vehicle windshield wiper system comprising in combination with a direct current electric motor for operating the wipers and a source of direct current operating potential, a variable resistor, a capacitor, an electric switch having first and second pairs of contacts arranged in such a manner that when one pair of contacts is open the other pair of contacts is closed, means for connecting said electric motor and said first pair of contacts in series across said source of direct current operating potential, means for connecting said second pair of contacts, said variable resistor and said capacitor in series across said source of direct current operating potential, a unijunction transistor having two base electrodes and a control electrode, an electric relay having an operating coil and a pair of normally open contacts, means for connecting said second pair of contacts of said electric switch, said base electrodes of said unijunction transistor and said opeRating coil of said relay in series across said source of direct current operating potential, means for connecting said control electrode of said unijunction transistor to the junction between said series connected resistor and capacitor, and means for connecting said electric motor and said normally open contacts of said electric relay in series across said source of direct current operating potential.
Claim 2
Dependent Claim
214 words
A vehicle windshield wiper system comprising in combination with a direct current electric motor for operating the wipers and a source of direct current operating potential, a variable resistor, a capacitor, an electric switch having first and second pairs of contacts arranged in such a manner that when one pair of contacts is open the other pair of contacts is closed, means for connecting said electric motor and said first pair of contacts in series across said source of direct current operating potential, means for connecting said second pair of contacts, said variable resistor and said capacitor in series across said source of direct current operating potential, a unijunction transistor having two base electrodes and a control electrode, an electric relay having an operating coil and a pair of normally open contacts, means for connecting said second pair of contacts of said electric switch, said base electrodes of said unijunction transistor and said opeRating coil of said relay in series across said source of direct current operating potential, means for connecting said control electrode of said unijunction transistor to the junction between said series connected resistor and capacitor, and means for connecting said electric motor and said normally open contacts of said electric relay in series across said source of direct current operating potential.
Claim 3
Dependent Claim
252 words
A vehicle windshild wiper system comprising in combination with a direct current electric motor for operating the wipers and a source of direct current operating potential, a parking switch having a movable contact operated in synchronism with said electric motor to an open position when said wipers are in a predetermined park position, means for connecting said parking switch in series with said electric motor across said source of direct current operating potential, a variable resistor, a capacitor, an electric switch having first and second pairs of contacts arranged in such a manner that when one pair of contacts is open the other pair of contacts is closed, means for connecting said first pair of contacts in parallel with said parking switch, means for connecting said second pair of contacts, said variable resistor and said capacitor in series across said source of direct current operating potential, a unijunction transistor having two base electrodes and a control electrode, an electric relay having an operating coil and a pair of normally open contacts, means for connecting said pair of contacts of said electric switch, said base electrodes of said unijunction transistor and said operating coil of said relay in series across said source of direct current operating potential means for connecting said control electrode of said unijunction transistor to the junction between said series connected resistor and capacitor, and means for connecting said electric motor and said normally open contacts of said electric relay in series across said source of direct current operating potential.
Claim 4
Dependent Claim
252 words
A vehicle windshild wiper system comprising in combination with a direct current electric motor for operating the wipers and a source of direct current operating potential, a parking switch having a movable contact operated in synchronism with said electric motor to an open position when said wipers are in a predetermined park position, means for connecting said parking switch in series with said electric motor across said source of direct current operating potential, a variable resistor, a capacitor, an electric switch having first and second pairs of contacts arranged in such a manner that when one pair of contacts is open the other pair of contacts is closed, means for connecting said first pair of contacts in parallel with said parking switch, means for connecting said second pair of contacts, said variable resistor and said capacitor in series across said source of direct current operating potential, a unijunction transistor having two base electrodes and a control electrode, an electric relay having an operating coil and a pair of normally open contacts, means for connecting said pair of contacts of said electric switch, said base electrodes of said unijunction transistor and said operating coil of said relay in series across said source of direct current operating potential means for connecting said control electrode of said unijunction transistor to the junction between said series connected resistor and capacitor, and means for connecting said electric motor and said normally open contacts of said electric relay in series across said source of direct current operating potential.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |