Geometrical instruments – Straight-line light ray type – Alignment device
Reexamination Certificate
1999-06-10
2001-06-05
Gibson, Randy W. (Department: 2859)
Geometrical instruments
Straight-line light ray type
Alignment device
C033S390000, C033S451000, C033S452000, C033S471000, C033S484000, C033S529000, C033SDIG002
Reexamination Certificate
active
06240649
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to sighting devices, and more particularly to laser beam sighting assemblies useful in aligning pipe segments and flanges in the course constructing a pipeline.
2. Description of the Prior Art
The process of constructing a pipeline or pipe run often entails a sequence of welds in which long segments of pipe are joined to bend segments and flanges. In this process the accumulated build up of welding tolerances and welding heat distortions require continuous realignment sighting, with compensating grinding adjustments made at each weld joint. Thus the pipe fitter is constantly measuring angles, adjusting the weld lines and re-sighting in order to obtain a proper drainage slope and a true flange surface at the end of a run.
Maintaining a proper slope and flange surface alignment is particularly difficult at a pipeline bend. Here the length tolerances compound the angular tolerances and the pipe fitter therefore needs to adjust both the length and the angular segment of the bend to maintain slope and flange geometry. In this setting various sightings are taken along the pipe and the bend segments which with the use of trigonometry resolve the final flange joint plane.
This cumbersome process renders any construction assignment in which the pipe run needs to drain in a particular direction both difficult and geometrically indeterminate. For example, typical drain slopes are ⅛ or ¼ inch per foot and any distortion or misalignment of the bend can form undrained traps or pockets that promote corrosion. Thus a continuing requirement subsists for a quick verification of the slope and its general direction as the pipe segements are welded.
Heretofore various surveying assemblies have been devised which in one or another manner provide accurate measurement of the various geometrical points and lines. Examples of such surveying assemblies are shown in U.S. Pat. No. 3,813,170 to Sears; U.S. Pat. No. 3,897,637 to Genho; U.S. Pat. Nos. 4,973,158 to Marsh; and 5,218,770 to Toga. While each describes an accurate surveying instrument, the precise and complex surveyor's procedure is not practical at each weld and therefore primarily useful to set the end references or the reference line. Alternatively, portable measuring devices have been developed incorporating complex electronic systems that render convenient most remote measuring tasks, exemplified in U.S. Pat. Nos. 5,075,977, 5,287,627 and 5,182,863, all to Rando. While suitable for the purposes intended each of the foregoing entails complex precision instrumentation that is expensive to produce and maintain and subject to damage.
A simple, inexpensive and rugged sighting assembly particularly suited to the quick slope and azimuth adjustments made in the course of welding a pipe run is desired and it is one such assembly that is disclosed herein.
SUMMARY OF THE INVENTION
Accordingly, it is the general purpose and object of the present invention to provide a sighting assembly useful in determining the general slope of pipe bend segments in order to align the end flanges of a pipeline.
Other objects of the invention are to provide a simple and rugged sighting assembly useful in the construction of pipelines.
Yet further objects of the invention are to provide a portable sighting assembly conformed for quick resolution of geometry in the course of constructing a pipeline.
Briefly these and other objects are accomplished within the present invention by providing a portable sighting assembly characterized by an elongate body including a pivot proximate one end from which an arm of a protractor is frictionally deployed. A laser beam pointer is fixed to in the body, aligned along the primary axis thereof, adjacent a hemispherical level vial for defining a level plane. This level may be part of a magnetic compass assembly, imbedded in the dial cover lens thereof, and may include concentric scribes or markings indicating the slope. An adjustable azimuth ring surrounding the lens vial then assists in defining the magnetic direction of the slope, the ring extending into two opposed lateral recesses formed in the sides of the body for manipulative convenience.
To align the inventive sighting assembly against the exterior surface of a pipe bend segment the arm may be provided with a thumb screw affixed forward and rear bracket selectively securable along the length of the arm edge, each deploying a corresponding vertically spaced pair of contact points for contacting the measured surface. The spacing between the brackets together with the dimension of the contact points combine to define a measuring cage selected to match the pipe diameter and bend radius, thereby providing a convenient set of contacts for aligning the sighting assembly on the pipe. When the protractor arm is collapsed into the profile of the body these brackets are then received in the recesses on the sides of the compass azimuth ring.
A second, even more rugged, sighting assembly may be provided with two orthogonal level vials along and across the longitudinal dimension of the body, again in visual proximity with the magnetic compass. The compass is once more aligned between the lateral recesses to expose the edge of the azimuth ring. In this implementation the protractor arm may be useful without the brackets, functioning as an alignment guide along the pipe exterior.
REFERENCES:
patent: 4144650 (1979-03-01), Rawlings et al.
patent: 4394801 (1983-07-01), Thibodeaux
patent: 4693011 (1987-09-01), Strayham
patent: 4744152 (1988-05-01), Roach et al.
patent: 5239761 (1993-08-01), Wu et al.
patent: 5452522 (1995-09-01), Kook et al.
patent: 5586395 (1996-12-01), Malczewski
patent: 5604987 (1997-02-01), Cupp
patent: 5669149 (1997-09-01), Meitzler
patent: 5749152 (1998-05-01), Goss et al.
patent: 5839201 (1998-11-01), Young
patent: 6104480 (2000-08-01), Matzo et al.
Gibson Randy W.
Quirk & Tratos
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