Retractable plumb and chalk line
US4459761A · kind A · utility
Inventor
Key dates
| Filing date | Jan 10, 1983 |
| Grant date | Jul 17, 1984 |
| Priority date | — |
| Expiry date | Jan 10, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB44D3/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention contemplates a plumb-indicating and marking tool whereby marking a plumb line on a wall or other structure is a simple one-handed operation, so that the user, who may be in an otherwise precarious position on a ladder, may have one hand free at all times to assure his own personal safety. A casing encloses a reeled chalk line as well as a plumb bob connected to the chalk line, and the reel may be releasably locked for the retracted or for any desired line pay-out condition. Provision is made for fastening the casing to the user's belt, in upside-down condition, whereby selection of payout length is readily accomplished and chalk-dusting of the line is automatic.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.