Patent ID: 7984557
Filing Date: 2011-07-26
Classification: B66C,E06C,G01C,G01S,Y10S

Abstract:
1. A positioning device for enabling an operator to guide an outer end of a longitudinally movable extendable member having its opposite end adjacent a substantially horizontal surface to a desired position at a substantially vertically-extending surface, said positioning device comprising: a housing having first and second openings that have respective axes that are angularly disposed relative to each other, wherein the axes of the openings lie in a common plane; a first laser light source positioned within the housing for directing a first laser light beam through the first opening in the housing; a second laser light source positioned within the housing for directing a second laser light beam through the second opening in the housing; wherein the first laser light source projects the first laser light beam that extends parallel to an intended movement direction of an extendable member to which the positioning device is attached and provides a first predetermined laser light image that impinges on the substantially vertically-extending surface at a desired position on the substantially vertically-extending surface toward which the outer end of the extendable member is intended to be moved, and the second laser light source projects the second laser light beam that provides a second predetermined laser light image on the surface and in a direction that is angularly offset from the direction of the first laser light beam, so that the first and second light images on the surface converge as the end of the extendable member approaches the desired position on the substantially vertically-extending surface; and attachment means for attaching the housing to an extendable member.