US3727242A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level indication apparatus
Assignee: Thetford LLC
•
Filing: 1971-09-20
•
Granted: 1973-04-17
•
Expires: 1991-09-20
Abstract
Abstract Apparatus for indicating level of liquid in a recirculation type toilet or in other containers or tanks comprising an indicator lens which is free from any moving elements and indicates the level of the liquid by the application of the laws of light refraction.
Inventors
- 👤 M Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:35
CPC Classifications
E; E03; E03D; E03D5/00; E03D5/016; G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284; G01F23/292; G01F23/2921; G01F23/2922; Y; Y10; Y10T; Y10T137/00; Y10T137/8158; Y10T137/8359
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
228 words
A recirculating type toilet having a holding tank, a bowl positioned in the upper portion of said holding tank and having a discharge outlet at its bottom in communication with the interior of the holding tank, a recirculation pump with an inlet adjacent to the bottom of said holding tank, and a liquid level indicator mounted in the wall of said holding tank for indicating the level of liquid in said tank, said tank having a vertical slot in the wall of said tank extending from approximately the level of said inlet of the pump to approximately the level of said outlet of the bowl, said indicator being a transparent prism mounted in said slot to close the same and having a front face exposed to the interior of the tank and rear faces exposed to the interior of the tank, the front and rear faces being arranged so that substantially total reflection of light from the exterior of the tank will occur only at those portions of the rear faces that are above the liquid level in the tank, said indicator having indicia indicating the lower end upper limits for liquid in said tank, the indicium indicating the lower limit being above the level of the inlet of said pump and the indicium indicating the upper limit being below the level of the outlet of said bowl.
Claim 2
Dependent Claim
228 words
A recirculating type toilet having a holding tank, a bowl positioned in the upper portion of said holding tank and having a discharge outlet at its bottom in communication with the interior of the holding tank, a recirculation pump with an inlet adjacent to the bottom of said holding tank, and a liquid level indicator mounted in the wall of said holding tank for indicating the level of liquid in said tank, said tank having a vertical slot in the wall of said tank extending from approximately the level of said inlet of the pump to approximately the level of said outlet of the bowl, said indicator being a transparent prism mounted in said slot to close the same and having a front face exposed to the interior of the tank and rear faces exposed to the interior of the tank, the front and rear faces being arranged so that substantially total reflection of light from the exterior of the tank will occur only at those portions of the rear faces that are above the liquid level in the tank, said indicator having indicia indicating the lower end upper limits for liquid in said tank, the indicium indicating the lower limit being above the level of the inlet of said pump and the indicium indicating the upper limit being below the level of the outlet of said bowl.
Claim 3
Dependent Claim
50 words
The recirculating type toilet that is defined in claim 1, wherein said transparent prism has a front face parallel to a plane defined by said slot, and two rear faces symmetrically arranged relative to the front face and inclined at angles of 45* to a perpendicular from said front face.
Claim 4
Dependent Claim
41 words
The recirculating type toilet that is defined in claim 1, wherein said transparent prism has laterally projecting portions which are secured to the edges of said slot so That the opening in the wall provided by the slot is sealed closed.
Claim 5
Dependent Claim
20 words
The recirculating type toilet that is defined in claim 1, wherein said transparent prism is a clear acrylic plastic material.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |