Scale balancing device in universal parallel ruler device
US4587742A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 9, 1985 |
| Grant date | May 13, 1986 |
| Priority date | — |
| Expiry date | Jan 9, 2005 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB43L13/08
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A scale balancing device for balancing the weight of the scales of a universal parallel ruler, the device having a head structure having the scales rotatably mounted thereon, a rotating member rotatably mounted on the head structure separate from the scales, the rotating member and the rotatable scales being rotatably interlocked, and a spring having one end rotatably connected to a point on the rotating member eccentric to the axis of rotation thereof and the other end rotatably connected to a non-rotatable part of the head structure, the spring, when the scales are rotated to a position vertically in line with the axis of rotation thereof, having substantially no tension therein and when the scales are rotated ninety degrees from such position, having tension for exerting a maximum force on the eccentric connection point on the rotating member and sufficient in magnitude and having a direction which substantially cancels out the torque on the rotating member from the weight of the scales.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.