Laser vertical collimator

Claim 1

Apparatus for establishing a plumb line comprising an enlarged apertured support adapted for attachment to a stationary object, an annular horizontal first bearing member in said support, an elongated substantially vertical tube having a second bearing member adjacent its upper end shaped to rest upon said first bearing member in a relatively frictionless relation whereby the weight of said tube causes said tube to assume a vertical direction, a laser source having a casing fitting within said tube with the axis of said source parallel to said tube to emit a vertical laser beam through a first end of said tube, and an electric cord for said source extending through a second end of said tube, said tube rotatable relative to said first bearing member about a substantially vertical axis of rotation to permit formation of a circle of error of the laser beam for precise collimation of said beam.

Claim 7

A method of surveying comprising vertically mounting a laser beam source resting on a horizontal bearing to permit free angular movement of said source relative to said bearing about two perpendicular horizontal axes, whereby the weight of said source causes the source to assume a vertical position and the laser beam emitted to be vertical, energizing said source to produce a vertical laser beam and measuring an offset from said beam by illuminating a target from said beam and measuring distance from said target, said source also mounted rotatable relative to said bearing to permit forming a circle of error on a sensor illuminated by said beam to precisely collimate said beam, said source being rotated to illuminate a sensor below said source to establish a true vertical line between said source and said sensor by forming a circle of error at said sensor before measuring said offset.

Claim 8

A method of surveying comprising vertically mounting a laser beam source resting on a horizontal bearing to permit free angular movement of said source relative to said bearing about two perpendicular horizontal axes, whereby the weight of said source causes the source to assume a vertical position and the laser beam emitted to be vertical, energizing said source to produce a vertical laser beam and measuring an offset from said beam by illuminating a target from said beam and measuring distance from said target, said source also mounted rotatable relative to said bearing to permit forming a circle of error on a sensor illuminated by said beam to precisely collimate said beam, said source being rotated to illuminate a sensor below said source to establish a true vertical line between said source and said sensor by forming a circle of error at said sensor before measuring said offset.

Claim 9

A method of surveying comprising establishing a first line at a first elevation, vertically mounting a first laser beam source resting on a first horizontal bearing to permit free angular movement of said first source relative to said first bearing about two perpendicular horizontal axes whereby the weight of said firSt source causes said first source to assume a vertical position and the first laser beam emitted therefrom to be vertical and to intersect said first line, vertically mounting a second laser beam source resting on a second horizontal bearing to permit free angular movement of said second source relative to said second bearing about two perpendicular horizontal axes whereby the weight of said second source causes said second source to assume a vertical position and the second laser beam emitted therefrom to be vertical and to intersect said first line, energizing said first and second sources to produce vertical first and second beams, respectively, locating a first target illumination by said first beam at a second elevation, locating a second target illuminated by said second beam at said second elevation, and establishing a second line at said second elevation by sighting along both said targets, said second line parallel to said first line.

Claim 10

A method of surveying comprising establishing a first line at a first elevation, vertically mounting a first laser beam source resting on a first horizontal bearing to permit free angular movement of said first source relative to said first bearing about two perpendicular horizontal axes whereby the weight of said firSt source causes said first source to assume a vertical position and the first laser beam emitted therefrom to be vertical and to intersect said first line, vertically mounting a second laser beam source resting on a second horizontal bearing to permit free angular movement of said second source relative to said second bearing about two perpendicular horizontal axes whereby the weight of said second source causes said second source to assume a vertical position and the second laser beam emitted therefrom to be vertical and to intersect said first line, energizing said first and second sources to produce vertical first and second beams, respectively, locating a first target illumination by said first beam at a second elevation, locating a second target illuminated by said second beam at said second elevation, and establishing a second line at said second elevation by sighting along both said targets, said second line parallel to said first line.