US3885580A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dishwasher control system
Assignee: General Electric Co
•
Filing: 1974-04-04
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Granted: 1975-05-27
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Expires: 1994-04-04
Abstract
Abstract A liquid level responsive switch assembly for a dishwasher or like washing appliance including a movable liquid-displaceable member, within the washing chamber, having a plunger extending through an opening in the chamber bottom and operably connected to a switch located outside the chamber, the switch being adapted for positioning to an upper or lower position by vertical movement of the liquid-displaceable member as the liquid level changes within the chamber, said liquid level responsive switch assembly further including movable lever means extending through a second opening in the chamber bottom, said lever means being adapted to hold said movable liquid-displaceable member in its uppermost position when there exists a positive liquid pressure at the pump outlet of the washing appliance, thereby preventing switch movement as a consequence of a temporary liquid level drop within the washing chamber of the appliance.
Inventors
- 👤 Donald S Cushing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:17
CPC Classifications
A; A47; A47L; A47L15/00; A47L15/42; A47L15/4244; D; D06; D06F; D06F39/00; D06F39/08; D06F39/087; H; H01; H01H; H01H35/00; H01H35/18; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/729
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
In a dishwasher of the type having a washing chamber, spray means contained within said washing chamber for distributing washing liquid therein, a pump in flow communication with said spray means for delivering said washing liquid to said spray means, a motor driving said pump and an electrical control circuit for regulating said motor and providing various cycles of operation of said dishwasher, the invention comprising: (a) a switch assembly operatively connected to the electrical control circuit of the dishwasher; and (b) pressure activated control means in pressure communication with the outlet of said pump adapted to operate said switch assembly in response to pressure changes at the outlet of said pump.
Claim 2
Dependent Claim
112 words
In a dishwasher of the type having a washing chamber, spray means contained within said washing chamber for distributing washing liquid therein, a pump in flow communication with said spray means for delivering said washing liquid to said spray means, a motor driving said pump and an electrical control circuit for regulating said motor and providing various cycles of operation of said dishwasher, the invention comprising: (a) a switch assembly operatively connected to the electrical control circuit of the dishwasher; and (b) pressure activated control means in pressure communication with the outlet of said pump adapted to operate said switch assembly in response to pressure changes at the outlet of said pump.
Claim 3
Dependent Claim
51 words
The combination set forth in claim 1 wherein said switch assembly is a liquid level responsive switch assembly and said pressure activated control means is adapted to maintain said switch assembly in a preset position as a consequence of a positive liquid pressure being exerted by said pump at its outlet.
Claim 4
Dependent Claim
102 words
The combination set forth in claim 2 wherein said switch assembly includes a float member within said washing chamber capable of being buoyed from a first to a second position in response to a change of liquid level in said washing chamber, and a movable plunger connected to said float member and projecting through an opening in a bottom wall of said washing chamber, and an electrical switch positioned outside said washing chamber operated by said plunger in response to movement of said float, and said pressure activated control means includes support means adapted to maintain said float in its second position.
Claim 5
Dependent Claim
47 words
The combination set forth in claim 3 wherein said dishwasher further includes a substantially vertical stand tube having a longitudinal passage therethrough for operably receiving said plunger therein, and bellows means in combination therewith acting normally to contain said plunger in its position relative said wash chamber.
Claim 6
Dependent Claim
71 words
The combination set forth in claim 3 wherein said pressure activated control means comprises a pressure tap connected in flow communication with said pump outlet and in flow communication with a transducer, said transducer being operably attached to L-shaped lever means juxtapositioned below one edge of said float to maintain said float in its second position as a consequence of pressure liquid pressure being exerted by said pump at its outlet.
Claim 7
Dependent Claim
52 words
The combination set forth in claim 5 wherein said transducer comprises a downwardly biased piston located within a cylinder portion, said piston having said L-shaped lever attached thereto in slidable relationship to said cylinder and supported therefrom to allow movement of said piston and said lever as a unit within said cylinder.
Claim 8
Dependent Claim
31 words
The combination set forth in claim 6 wherein said piston further includes a seal member attached to its upper side to prevent liquid from passing between said cylinder and said piston.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |