Patent US4540891A successfully refreshed from Google Patents.
US4540891A
Expired / Lapsed
US
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High current float switch
Assignee: RW BECKETT Corp A OH CORP
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Filing: 1983-11-02
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Granted: 1985-09-10
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Expires: 2003-11-02
Abstract
Abstract A float switch for providing a switching path for a high level electric current in response to a fluid level. A buoyant float housing includes a pair of conductors through the housing which are adapted to receive a potential difference. A high current solid state switching device in the housing provides a current path between the conductors inside the housing. The solid state switching device is mounted to a heat sink cup exposed through an opening in the float housing to the fluid level. A wide angle mercury switch is provided to trigger the solid state switching device in response to a change in the float housing orientation.
Inventors
- 👤 Robert M. Keener
- 👤 Shekhar Chakrawarti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:42
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/30; G01F23/32; G01F23/36; H; H01; H01H; H01H35/00; H01H35/18; H01H35/186; H01H29/00; H01H29/20; H01H9/00; H01H9/54; H01H9/547
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
127 words
A float switch for providing a switching path for a high level electric current in response to a fluid level comprising: a buoyant float housing having a pair of conductors extending through said housing, to provide first and second connection ends for said switching path adapted to receive a potential difference; a high current solid state switching device inside said housing connected to a heat transfer surface exposed through an aperture of said housing; said device providing a current path between said conductors inside said housing; and an annular position sensor connected to said switching device, said sensor connected to trigger said switching device into a conducting state in response to a position change of said float, whereby said switching device passes a current between said conductors.
Claim 2
Dependent Claim
127 words
A float switch for providing a switching path for a high level electric current in response to a fluid level comprising: a buoyant float housing having a pair of conductors extending through said housing, to provide first and second connection ends for said switching path adapted to receive a potential difference; a high current solid state switching device inside said housing connected to a heat transfer surface exposed through an aperture of said housing; said device providing a current path between said conductors inside said housing; and an annular position sensor connected to said switching device, said sensor connected to trigger said switching device into a conducting state in response to a position change of said float, whereby said switching device passes a current between said conductors.
Claim 3
Dependent Claim
17 words
The float switch of claim 1 wherein said high current solid state switching device is a triac.
Claim 4
Dependent Claim
34 words
The float switch of claim 2 wherein said level sensor is a mercury switch supported in said housing, and connected between a trigger electrode of said triac and a main terminal of said triac.
Claim 5
Dependent Claim
18 words
The float switch of claim 3 further comprising a transient suppression circuit connected across said triac main terminals.
Claim 6
Dependent Claim
154 words
A float switch for providing a switching path for a high level current in response to a fluid level comprising: a buoyant float housing supporting an electric circuit comprising: a triac having first and second main terminals and a trigger terminal; a mercury switch connected between one of said main terminals and said trigger terminal, said mercury switch closing in response to a position change of said float housing; said triac mounted to a heat transfer surface exposed through an aperture in said float housing to said fluid level, for transferring heat from said triac; and a pair of conductors, each connected to a main terminal of said triac through a sealed opening in said buoyant float housing, said conductor pairs adapted to be connected to a potential source and motor connection, whereby a current path is established through said conductors and triac in response to a position change of said buoyant float housing.
Claim 7
Dependent Claim
154 words
A float switch for providing a switching path for a high level current in response to a fluid level comprising: a buoyant float housing supporting an electric circuit comprising: a triac having first and second main terminals and a trigger terminal; a mercury switch connected between one of said main terminals and said trigger terminal, said mercury switch closing in response to a position change of said float housing; said triac mounted to a heat transfer surface exposed through an aperture in said float housing to said fluid level, for transferring heat from said triac; and a pair of conductors, each connected to a main terminal of said triac through a sealed opening in said buoyant float housing, said conductor pairs adapted to be connected to a potential source and motor connection, whereby a current path is established through said conductors and triac in response to a position change of said buoyant float housing.
Claim 8
Dependent Claim
12 words
The float switch of claim 5 wherein said mercury switch is omnidirectional.
Claim 9
Dependent Claim
121 words
A level activated switch for providing a current switching path in response to a fluid level change comprising: a buoyant float member having a central cavity extending through a first and second aperture in said float member; a circuit disposed within said cavity including: a semiconductor switch having a heat transfer surface, an angular position sensitive switch connected to trigger said semiconductor switch, and first and second conductors serially connected by said semiconductor switch, said conductors exiting through said second aperture in said buoyant float member; and a heat sink cup for sealing said first aperture, said cup supporting said semiconductor switch in heat transfer relationship with said buoyant float member exterior, whereby said cavity is sealed against said fluid level.
Claim 10
Dependent Claim
121 words
A level activated switch for providing a current switching path in response to a fluid level change comprising: a buoyant float member having a central cavity extending through a first and second aperture in said float member; a circuit disposed within said cavity including: a semiconductor switch having a heat transfer surface, an angular position sensitive switch connected to trigger said semiconductor switch, and first and second conductors serially connected by said semiconductor switch, said conductors exiting through said second aperture in said buoyant float member; and a heat sink cup for sealing said first aperture, said cup supporting said semiconductor switch in heat transfer relationship with said buoyant float member exterior, whereby said cavity is sealed against said fluid level.
Claim 11
Dependent Claim
12 words
The apparatus of claim 7 wherein said semiconductor switch is a triac.
Claim 12
Dependent Claim
25 words
The level actuated switch of claim 7 wherein said angular position sensitive switch is omnidirectional and immune to rotational changes in said buoyant float member.
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) | 1988-09-09 | 1989-03-11 | 1989-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-09 | 1993-03-11 | 1993-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-09 | 1997-03-11 | 1997-09-10 | $7700.00 | Window Closed / Lapsed |