US 6,487,010 B2 · Focusing drive for optical instruments

Abstract

The invention describes a focusing drive for optical instruments that has, in addition to a pinion (1) and toothed rack arrangement (1, 2), slide rods (4) as guidance means for continuously changing the relative position of optical assemblies with respect to one another. The toothed rack (2) has a plurality of support elements (3) that are arranged—for example in angled fashion—on either side of its longitudinal extent. The support elements (3) are designed so that they have a shallow S-shape in cross section. In addition, they are dimensioned in such a way that they touch the contact surface of the one housing module (5) only with their planar end regions (3a). The result is a resilient or flexing motion upon actuation of the pinion (1), thus achieving smooth and zero-backlash adjustment.

Claims17

Dependent claims

A focusing drive for changing the position of a second assembly (5) relative to a first assembly (6) in optical instruments, said focusing drive comprising:

a pinion (1) mounted on said first assembly;
an elongated plastic toothed rack (2) meshing with said pinion;
a plurality of L-shaped support elements (3) cantilevered from said toothed rack along a longitudinal extent of said toothed rack, each of said plurality of support elements having an end region (3a) attached to said second assembly (5) to mount said toothed rack on said second assembly, said plurality of support elements acting to resiliently bias said toothed rack into meshing engagement with said pinion;
and
a plurality of slide rods (4) extending parallel to a longitudinal axis of said toothed rack, each of said plurality of slide rods being slidably received by a groove in said first assembly (6) and by a groove in said second assembly (5) to guide relative displacement between said first and second assemblies;
whereby zero-backlash guidance is achieved.

3 more elements

Dependencies are inferred from the claim text.

Focusing drive for optical instruments

Life of this patent

Focusing drive for optical instruments

Life of this patent

Abstract

Claims17