US3707338A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solenoid operated pump
Assignee: Individual
•
Filing: 1971-01-29
•
Granted: 1972-12-26
•
Expires: 1991-01-29
Abstract
Abstract The present invention relates to an electric solenoid operated, diaphragm pump of the type having a mechanically operated electrical switch for controlling cyclical solenoid energization. Prior pumps of this class passed a large electrical current through the switch contacts, leading to premature switch failure. The present application discloses an electronic circuit that minimizes the electrical current flow through the switch contacts. It also discloses an optical arrangement for replacing the mechanically operated electrical switch.
Inventors
- 👤 Michael H Hilford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:45
CPC Classifications
H; H02; H02K; H02K33/00; H02K33/02; H02K33/10; F; F04; F04B; F04B43/00; F04B43/02; F04B43/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
194 words
An electric fuel pump comprising: a pumping mechanism mounted for reciprocation; means comprising a driving rod affixed to said pump mechanism for causing said mechanism to be reciprocated; reciprocating means comprising a solenoid surrounding said driving rod for developing a magnetic force that causes said driving rod to move in one direction and a return spring; energizing means comprising a solenoid switch actuatable for energizing and de-energizing said solenoid; sensing means for sensing the position of said driving rod and producing a signal when said driving rod occupies a selected position; and actuating means for utilizing that signal for actuating said solenoid switch; said sensing means comprising a first light source and first light sensor and a shield mounted for movement with said driving rod from a position in which it is interposed between said first light source and said first light sensor to a position in which it is not interposed between said first light source and said first light sensor to a position in which it is not interposed between said first light source and said first light sensor when said driving rod is moved between said selected position and another position.
Claim 2
Dependent Claim
194 words
An electric fuel pump comprising: a pumping mechanism mounted for reciprocation; means comprising a driving rod affixed to said pump mechanism for causing said mechanism to be reciprocated; reciprocating means comprising a solenoid surrounding said driving rod for developing a magnetic force that causes said driving rod to move in one direction and a return spring; energizing means comprising a solenoid switch actuatable for energizing and de-energizing said solenoid; sensing means for sensing the position of said driving rod and producing a signal when said driving rod occupies a selected position; and actuating means for utilizing that signal for actuating said solenoid switch; said sensing means comprising a first light source and first light sensor and a shield mounted for movement with said driving rod from a position in which it is interposed between said first light source and said first light sensor to a position in which it is not interposed between said first light source and said first light sensor to a position in which it is not interposed between said first light source and said first light sensor when said driving rod is moved between said selected position and another position.
Claim 3
Dependent Claim
72 words
The invention defined in claim 1 in which said sensing means comprises a second light source and a second light sensor mounted such that said shield is interposed between said second light source and said second light sensor when said driving rod occupies said selected position; and means for preventing operation of said first mentioned light source when said shield is interposed between said second light source and said second light sensor.
Claim 4
Dependent Claim
118 words
The invention defined in claim 2 in which said sensing means further comprises a NAND gate in series with said first light source, three reversing amplifiers, and in which said solenoid switch comprises a solid state switch arranged with an input terminal such that the switch is closed unless a signal is applied to its terminal, one of said reversing amplifiers being connected between said first light sensor and the input terminal of the solid state switch, another of said reversing amplifiers being connected between a terminal of the solenoid and one control terminal of the gate, and the third of said reversing amplifiers being connected from said second sensor to the other control terminal of the gate.
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) | 1975-12-26 | 1976-06-26 | 1976-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-26 | 1980-06-26 | 1980-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-26 | 1984-06-26 | 1984-12-26 | $7700.00 | Window Closed / Lapsed |