Mechanisms for mounting cam barrels
US5285322A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1992 |
| Grant date | Feb 8, 1994 |
| Priority date | — |
| Expiry date | Sep 8, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens includes a lens group mounted in a cam barrel mechanism which includes a fixed barrel with a cam barrel rotationally mounted thereon. The lens group has a pin which projects through an axially extending clearance slot in the fixed barrel and a compliant feature on the pin removes the clearance between the pin and the slanted cam slot in the cam barrel so that as the cam barrel is rotated the lens group translates axially within the fixed barrel. The fixed barrel has an endcap with array of centering orifices mounted thereon and a beveled surface which is engaged by an outboard edge of the cam barrel. The cam barrel is urged against the endcap by a wave washer disposed between the cam barrel and a base. Radially disposed with respect to the cam barrel are a pair of spaced lugs and a bowed sheet spring which engages the cam barrel to urge the cam barrel against the lugs. The wave washer and bowed sheet spring positively locate the cam barrel with zero clearance. As long as the spring forces of the wave washer and bowed sheet spring are not exceeded, the cam barrel is limited only to rotational motion with respect to the fixed barrel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.