Chemical tablet with central hole and partially exposed top and bottom
US5137731A · kind A · utility
10Cited by
9References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 2, 1991 |
| Grant date | Aug 11, 1992 |
| Priority date | — |
| Expiry date | Dec 2, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2103/42
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A toroidal chemical tablet with a close fitting water impervious peripheral barrier surrounding its sides with exposed upper and lower annular surfaces is disclosed. The tablet has a central hole to aid in water flow and dissolves inside out for even feeding. Also disclosed is a pool chemical tablet partially encased in a covering which when placed in a pool skimmer gives a visual indication when the tablet is substantially dissolved, as well as methods for using the tablet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.