Friction drive for metering device
US4539854A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1983 |
| Grant date | Sep 10, 1985 |
| Priority date | — |
| Expiry date | Oct 13, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F11/021
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a fluid metering system, a plunger actuated syringe is coupled to at least one source of fluid, and a highly accurate friction drive is coupled to the plunger for moving fluid to a delivery outlet. The friction drive has a rack having a flat side and a rotatable circular drive shaft, or pinion, pressed against the flat side of the rack for moving the same by friction. Opposed guide rollers engage the rack in opposition to the flat side in straddling relation with the pinion for urging the rack thereagainst. A moveable swing arm supports one of the guide rollers against the rack. A spring leverages the swing arm and guide roller against the rack and transmits the force to the pinion. A positioning rod is provided for securing the swing arm and the moveable guide roller in a plane perpendicular to the flat side of the rack to prevent lateral motion of the rack and pinion whereby inaccuracies in the system may be minimized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.