Electronic digital tape-rule
US4575944A · kind A · utility
Inventor
Key dates
| Filing date | Jun 19, 1985 |
| Grant date | Mar 18, 1986 |
| Priority date | — |
| Expiry date | Jun 19, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2003/1035
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electronic digital tape rule consisting of a housing, a tape reel having an extendable and flexible measuring tape, a battery case, an actuator, a detector, a counter, a display and a brake. The actuator comprises a friction roll rotatably mounted on a shaft fixed at an inner wall of the housing, a disc disposed on the upper end of the roll and rotatable by the friction of the roll, a plate fixed on the upper end of the roll and having a hole with a pair of contact plates attached on the two side walls of the hole, a spring mounted between the disc and the plate for constantly pressing the disc against the roll and an actuating rod disposed upright on the upper side of the disc and having its upper end engaging with the hole. The actuating device in cooperation with the friction rolls can accomplish the switching action corresponding to the directions of rotation of the friction rolls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.