US2553571A - Bore sighting target - Google Patents

Description

Patentecl May 22, 1951 UNITED BORE SIGHTING TARGET Joseph Frans and Jacob Volk, New York, and Herbert J. Weth, Brightwaters, N. Y.

Application January 3, 1947, Serial No. 719,982

4 Claims. (01. 33-46) (Granted under the act of March 3, 1883, as amended. April 30, 1928; 370 0. G. 757) This invention relates to improvements in boresighting targets, and. more particularly to improvements in sighting devices adapted to square and center a target to a center line.

Sighting devices presently employed to center a target to a center line, as in boresighting, requ ire pursuit of the following procedure: a master target and a boresight bracket are set up at opposite ends of the shaft center 1ine, in accordance with blueprint measurements and data. A piurality of targets, which are square plates having cross-iines at right ang1es to each other, intersecting at the center of a small hole on a machined face of said plates are then set up at intrva1s along the shaft line. After sighting the master target with the boresight and setting the hairlines of the said boresight, the intermediate targets are moved into line, one at a time, by clamping them to a provided bracket and hamn ering or tapping them into aligned position according to telephoned instructions from the observer at the boresight. When centered, the target is drilled and bolted in place.

The disadvantages of the devices and. method presentiy employed are numerous: Targets must be repanted constantly and the grooves scraped and refilled with piaster-of-Paris. Despite precautions, the paint employed often causes glare as it refiects 1ight, thus creating a fa 1se impressioh of the location of the cross-line. Also, rain ari'd damp weather cause the paint to peel and discolor the plaster-of-Paris, making accurate reading more difficult.

Frequently, boresighting must be accomplished aboard a ship. Due to ship movements, each time a line is boresighted the targets have to be released, moved and redrilled. If external lights employed to illuminate the target cast a beam at an angle thereto, it is more diflicult to center the target. Further, both lights and the dri1l machine employed must be carried to each target, involving numerous set-ups.

The greater the distance between the target and the boresight, the greater is the width of the area covered by the harlines. Accordingly, at distances, the hairline will cover an area wider than the cross-line, thereby multiplying errors in setting the target. In addition, at substantial distances it is difficult to see the cross-lines clear- 1y and sharply; in present practice, at great distances the line must be boresighted in two or more sections, increasing the possibility of error due to moving the boresight for a second or third setting thereof.

A urther disadvantage of present practice is the fact that targets cannot be squared to the shaft centerline. The rake of the target will be the rake of the bracket which can only be approximate due to ship movement and due to the fact it is mere1y welded in position. This will cause deflections and inaccuracies in wires stretched between these targets.

Several men are required to accomplish the operation under present practices, since lights and telephone must be held at the target, the crude and tedious tapping or hammering of the target performed and the drilling machine used. There is also substantial wastage of material: Hundreds of wire clamps, having a high breakage rate, must be employed during the months before the final boresighting and proofmarkng are done. Scores of target clamps must be made for the process and many are lost, since they cannot be carried a1ong convenently with the lights, dril1 machine and other equipment and. must be abandoned or clamped to the bracket until needed again.

A11 of the foregoing disadvantages of present practices are substantially overcome by this invention.

The prmary object is to provide a simple and accurate boresighting device adapted to square and center a target to a shaft center line.

Another object is to provide a sight adapted to carry measuring instruments for proofmarking, centering and squaring an object.

Still another object is to provide a sight operable accurately regardless of movements of the surface upon which the work is positioned.

Another object is to provide a sight affording accuracy in use without regard to external 1ight sources and glare.

Another object is to provide a sight of convenent size and minimum number of parts in lieu of the bu1ky, cumbersome and complex devices presently employed.

A further object is to provide a sight that is accurate over great distances.

Another object is to provide a sight which in use wili effect a saving in time and 1abor.

Further objects and advantages of thisinvention, as well as its construction, arrangement and operation will be apparent from the following description and claims in connection with the accompanying drawing, in which Fig. 1 is an elevation of a boresighting target, showing a preferred embodiment of the invention; and.

Fig. 2 is a Side view thereof. part1y in section.

Simlar numerals refer to similar parts throughout the several views.

A frame H is mounted on a base I3, which is provided with a plurality of bo1ts |4 adapted to secure said base to a standard and beveled longitudinal walls i6 adapted to secure said base between the walls of a frame guide I 8 aiixed to said standard. Said frame II is provided with a plurality of paired guides |5, spaced 90 apart, eX- tending nwardly from said frame. A plurality of shoes Il, each adapted to ride between a pair of said guides, are each provided with a concave face I9 dista1 said frame adapted to engage the periphery of a mounting ring hereinafter described, and are secured to a plurality of set screws 2l extending through the Wa1ls of said frame, said set screws beng adapted to extend and retract said shoes.

A mounting rin 23 preferably in the shape of a mediai segment of a sphere, is carried between said shoes. Spaced points on the periphery of said ring 23 are contieuous with the concave faces |9 of said shoes so that said ring is both rotatable about its axis and. translatable to any plane oblique to the plane of the face of the frame within the limits prescrbed by the width of the segment constituting said ring. Said ring 23 is provded. with an annular flange 25 upon a fase thereof adapted to carry the ring of a crown hereinafter described, a plurality of key slots 21 in said fiange adapted to retan said crown ring against rotational displacement relative said ring 23, and a threaded axial bore 29 adapted to receive a plug clamp or a measuring instrument.

The crown comprises a ring and sighting assemblies: A ring 3I adapted to enage frictonally the periphery of the flange 25 is provided with a plurality of keys, which are engaged by the key slots 21. Radially disposed fins 33 spaced 90 apart extend from the periphery of said ring 3! and beyond the frame I and. carry sighting assemblies distal said ring. Said sighting assembiies each comprises a tube 35 disposed at a right angle to the plane of the face of said ring, a disc having a first radial slot 31, a1so radial said ring, mounted at one end of said tube, a source of light such as a bu1b 39 mounted at the other end of said tube and energized by suitable means (net shown), a light-diffusing disc H adjacent said source of light and intermediate said tube, and another disc having a second radial slot 43 adjacent said diifusing disc and spaced from said first slot, said second slot being disposed parallel to said first slot.

The operation of the device is performed as follows: After the centers for the master target and the boresight are ascertained and established from blueprint measurements and data, the shaft line is boresighted. Then, at desired intervals, a plurality of frames ll are set up, centered and squared approximately, and fixed into permanent postion in guides I8 by securing bolts I 4 to the standard. (It is to be observed that the ring 23 is adjustable in the frame I I by adjusting the set screws 21, so that ship movements can be compensated for by moving and rotating the ring without disturbin the frame from its fixed position.)

When boresighting, the crown is set upon the ring of one of the frames. Movements of said crown in a plane perpendicular to the shaft centerline are then accomplished by shoe adjustments, while by rotation of the ring in the shoes said crown is set square to the shaft centerline. By virtue of the construction above described, the

boresight hairlines are a1igned readily with their respective end slots 31 and. intermediate slots 53, the diffused light faclitating observation. At such time, the crown and the ring are squared and centered to the shaft centerline. In this position, the ring 23 i secured by lockng it in the shoes I"l, the crown removd and the pro cedure repeated successively at the other frames set up along the line.

If it is desred to stretch a wire along the centerline, a plug clamp can be inserted in the threaded bore of the ring 23 after said ring has been centered and squared as above described. Alternatively, a machined shaft carrying measuring instruments can be inserted in said bore, thereby permittng quicker and more accurate results than could be obtained by measuring from a stretched wire.

It is apparent that the sight above descrbed is adapted for use on any type of construction or assembly job where, due to the distances involved, wires are stretched for centerline measurements, or where long pipes or rods are suspended for the. purpose of aligning spaced equipment Which is to be joined by a connecting or quil1 shaft, such as a turbine, and reduction gear pinion. It is further apparent that the sight above described can carry a machined shaft which mounts a revoiving arm. For squaring and centerng operations, suitab1e dial indicators can be afiixed to said arm, whch can then be used for proofmarking, centering and other operations of like nature, wherein the dimensions and. distances involved are complcating factors.

Varous modifications and changes can be made in the subject device without departing from the scope of the invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

We claim:

1. A boresightin target comprising a frame, a plurality of paired guides in spaced relation extending inwardly from the walls of said frame, a plurality of shoes engaeed by said guides and reciprocable independently radial the center of said frame, means for moving said shoes, a member intermediate said shoes and adapted to be rotated and translated between said shoes, said member being provided with an axia1 bore, and a crown having a plurality of spaced radially extending fins mounted on a face of said member.

2. A boresighting target comprising a frame, a plurality of paired guides in spaced relation ex tending inwardly from the walls of said frame, a plurality of shoes engaged by said guides and reciprocable independently radia1 the center of said frame, means for moving said shoes, a member intermediate said shoes and adapted to be rotated and translated between said shoes, said member being provided with an axia1 bore and a fiange peripheral a face of said member, and a crown mounted on said fiange, said crown having a piurality of spaced radially extending fins, said fins carrying means for aligning a dstant object at right angles to the plane of said crown.

3. A boresighting target comprising a frame, a plurality of paired guides in spaced relation extending inwardly from the walls of said frame, a plurality of shoes engaged by said guides and reciprocable independently radial the center of said frame, a member in the shape of a medial segment of a sphere intermediate said shoes and adapted to be rotated and translated between sad shoes, sad member being prvded with an axia1 threaded bore and a fiange peripheral a face of sad member, a crown comprising a ring mounted on sad flange, radal fins 90 apart extending from sad ring and carrying tubes dstal sad ring, sad tubes being disposed at right angles to the plane of sad crown and being provided with spaced radial s1ots also radial sad ring.

4. A boresighting target comprising a frame, a plurality of paired guides in spaced. relation extending inwardly from the walls of sad 'frame, a plurality of shoes having concave faces engaged by sad guides and recprocable independently radial the center of sad frame, a member in the shape of a medial segment of a sphere intermediate sad shoes and adapted to be rotated and translated between sad shoes, sad member being provided with an axial threaded bore and a flange peripheral a face of sad member, a crown comprising a ring mounted on sad flange, radial fins 90 apart extending from sad ring and carryng tubes distal sad ring, sad tubes being disposed at right angles to the plane of sad crown, each tube being provided with a first radia1 slot also radia1 sad ring positioned at one end of sad tube, a source of 1ight at the other end of sad tube, a 1ight diffusing disc intermediate the ends of sad tube and another disc having a second radia1 slot also radial sad ring positioned intermediate sad disc and sad first slot.

JOSEPH FRANS. JACOB VOLK. HERBERT J. WETH.

REFERENCES CI'IED The following references are of record in the file of this patent:

UNITED STATES PATEN'I'S Number Name Date 461,389 Paoli Oct. 13, 1891 1,667 '995 Steinle May 1, 1928 1,770,451 Baker July 15, 1930 1,780384 Green Nov. 4, 1930 2,054090 Marple Sept. 15, 1936 2,285,768 Drucker June 9, 1942 FOREIGN PATENTS Number Country Date 96,423 Sweden Aug. 1, 1939

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