US1180886A - Method of and apparatus for locating sights on gun-barrels. - Google Patents

Description

E. T. STEPHENS.

METHOD OF AND APPARATUS FOR LOCATING SIGHTS 0N GUN BARRELS. I APPLICATION FILED JUNE 12. 1915.

Patented Apr. 25, 1916.

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THE COLUMBIA PLANOGRAPH c0., WASHINGTON, D. c.

ELWYN T. STEPHENS, OF SPRINGFIELD, MASSACHUSETTS.

To all whom it may concern:

Be it known that I, ELwYN T. STEPHENS, a citizen of the United States, residing in Springfield, I-lampden county, Massachusetts, have invented new and useful Improvements in the Method of and Apparatus for Locating Sights on Gun-Barrels.

In the art of manufacturing rifles it be comes necessary among other things to properly locate the sights so that all projectiles will be directed toward the object upon which the arm is sighted. It is a well known fact that it is not practicable and rarely possible to produce a rifle barrel wherein the bore is perfectly straight from end to end. It is also known that the pro jectile follows the direction imparted to it by the first two or three inches of the bore at the muzzle end of the barrel.

The common term for properly locating the sights on a rifle barrel is targeting and it is to be understood that in using that or right as the case may term reference is made to properly locating the sights so that when the rear sight is set on the zero mark the bullet will be directed toward the object sighted upon.

The present method of targeting a gun or locating the sights is to attach the rear sight locating the zero line in the center of the bore, then adjustably mounting the front sight and test the rifle by shooting at a target and moving the front sight to the left require, after each shot until the desired position is found or in other words, until the center of the tan get is pierced by the bullet when sighted, and the rifle is then considered to be properly sighted or targeted.

It is commonly found necessary to fire a rifle a considerable number of times, thus causing loss of time and ammunition. Now while such targeting may properly establish the location of the sights for one distance, it leaves them improperly located for any other distance unless it should happen that the bore is absolutely straight and that the front and rear sights are both located directly over the axis of the bore. This, however, probably in 99 per cent. of the instances is not possible, so that as a result the front sight is rarely located over the axis of the bore of the first two or three inches at the muzzle end, so that if the rifle be targeted so that the bullet will strike the center of the bulls-eye at 200 yds. (thisbeing the common distance for military or Specification of Letters Patent.

Patented Apr. as, rare.

Application filed June 12. 1915. Serial No. 33,853.

service rifle test) the bullet will not strike the center of the bulls-eye at 300, 400 yards or at any distance other than that for which it was targeted. It is also common in the locating of the sight on a rifle barrel to work from the outside upon the assumption that the bore is parallel in alinement' with the interior of the barrel. It will now be seen that if the bullet is controlled in its dlrection by the center line of the muzzle portion of the bore the gun, in order to be properly sighted, should have the front sight located directly above such center line and that the zero line of the rear sight should be located in perfect alinement or in the same vertical plane as the center line of the muzzle end of the bore and that, therefore, the front sight should be first accurately located directly above such center line and the necessary location of the zero line of the rear sight ascertained.

When the front and rear sights are 10- cated as above stated the gun will have been properly targeted so that no firing or change of adjustment of the sights is required.

As a means for accomplishing the desired result and as one means of exemplifying my invention I show an apparatus in the accompanying drawings wherein the direction of the bore at the muzzle end of the barrel is ascertained and from this point means are employed to locate the zero line of the rear sight so that the front sight and the zero line of the rear sight are in perfect alinement with and in the same vertical plane as the center line of the muzzle end of the bore.

In the accompanying drawings in which like letters of reference indicate like parts: Figure 1 is-a side elevation of a mechanism devised'by me as one means of carrying out my invention. Fig. 2 is a plan View of the same; In these two figures the barrel is shown in Fig. 1 and is omitted from Fig. 2. In this apparatus I may employ a suitable member comprising a perfected straight rod which I term the plug and which has a close sliding fit in the muzzle end of the barrel. The portion of this plug which projects beyondthe muzzle enters with a close sliding. fit a suitable member projecting vertically therefrom and firmly secured to said vertical member is an arm or bar of sufficient length toiextend' to'the rear portion of the arrel: and I prefer that one fa e of such,

perfect alinement with the axis of the plug so that if a marking tool be placed against this face and moved downwardly against the barrel at the point where the rear sight is to be located the location of the zero line of the rear sight may be ascertained and this being properly marked may be relied upon in locating the rear sight so that when it is set at the zero mark it will be in perfect alinement with the axis of the muzzle end of the bore. Explaining now the details of construction of said apparatus as illustrated in the drawings, I prefer that for conveniencein supporting the gun while ascertaining the proper location of the zero line for the rear 'sight, to provide a supporting mechanism comprising a suitable base as or having uprights b and a. The uprights 6 are provided with adjusting screws d adapted to bear against the side of the front sight. It is desirable that the forward sight be permanently fixed to the barrel in the same vertical plane and in' alinement with the axis at the bore at the muzzle end and this sight being fixed in position, the end of one'of the adjusting screws 03 being brought to a position which when one side of the sight bears against it, will bring the center line of the sight in the same plane as the center line or axis of the'bore, it simply becomes necessary to set up the other adjusting screw until it bears against the sight on the opposite side and thus rotate the barrel until both sides ofthe sight are in contact with the adjusting screws. The barrel will then be properly located with reference to the front sight being in the same vertical plane as the axis of the bore at arm or bar be in themuzzle end. I prefer that the upright 0 be provided with a laterally movable table e suitably supported to ride upon anti-friction mechanism which in the drawing I illustrate as rolls It will now be seen that when thegun is placed in position, the portion toward the stock resting upon the table 6 may be-moved laterally with perfect ease.

In Fig. 1 of the drawing I show the barrel marked 9 and a portion of the stock marked II). If the barrel and stock be now placed in position and the plug 2' inserted through the opening in the block j into the bore of the barrel at the muzzle end, the barrel will beimmediately brought into proper alinement without difliculty because of the lateral movement growing out of theemployment of the anti-friction table supporting mechanism. The block j is provided with a lower extension-7c pivotally mounted in the part Z which latter is pivotally mounted in the base a. The block 7' has firmly attached to it, the straight edge extension m, one face of which is in perfect alinement with the axis of the portion of the plug 2' which enters the muzzle end of the bore. e extension on has mounted upon it a sliding member a, provided with a marking tool 0, capable of vertical movement, so that when the plug is properly inserted at the muzzle end of the barrel, the marking tool 0 may be moved toward the barrel and the zero mark for the rear sight, and thus mark in the proper position so that it will be in perfect alinement or in the same vertical plane as the axis of the bore at the muzzle end of the barrel. In order to avoid danger of possible friction, and give the extension m perfect freedom of movement, I prefer that its free end be supported on a suitable table, the latter being supported by antifriction mechanism and for this purpose I have shown a table 7) on anti-friction rolls r the latter being supported by a suitable member s secured to the base a.

In order to adapt the apparatus for guns of different size bore, I prefer that the block j be provided with a bushing through which the plug passes and it will readily be seen that bushings of the same exterior diameter but of different interior diameter may be employed with the same block.

It will readily be seen that the method of ascertaining the location of the zero line for the rear sight invented by me, may be employed without the supporting apparatus illustrated in the drawings, although I deem this, as at present advised, the most convenient apparatus for the purpose. It will also be seen that very many modifications may be made without departure from my invention and I do not wish to be understood as limiting my claim to the specific mechanism herein explained for ascertaining the proper location of the zero line of the rear sight, or in other words, the targeting of a gun barrel.

It will readily be seen that if the gun be sighted or targeted so that a bullet will strike the center of the bulls-eye at a 200 yard range, the targeting being carried out in the old way, that is, by firing the gun and moving the front sight until the bullet strikes the center of the bulls-eye, that unless the bore be perfectly straight from end toend the arm will not be accurate at any range and that while the difference in accuracy at a distance nearly approximating 200 yards may be said to be trifling and microscopic, it will also be seen that at a range of a mile or more, or at the extreme limit of the carrying capacity of the arm, such inaccuracy is likely to be serious. It will also be seen that the old method of targeting guns comprising firing and adjusting the forward sight is tedious and expensive and the accuracy as to the range of test is largely dependent upon the personality of the person making the test and that by the old method the targeting relates only to one distance.

So far as known to me, no means has heretofore been provided by which the zero or proper mark for the center line of the rear sight has been scientifically or mechanically ascertained.

Having therefore described my invention, what I claim as new and desire to secure by Letters Patent, is,-

1. The method herein described of targeting gun-barrels, the same comprising first locating the front sight in the same vertical plane with the axis of the bore at the muzzle end of the barrel and then locating the zero line for the rear sight in perfect alinement with the vertical plane of the axis of the bore at the muzzle end of the barrel.

2. The improvement in the art of targeting gun-barrels, comprising first ascertaining the direction of the bore at the muzzle end of the barrel, locating the position of the front sight above and in line with the axis of such bore, ascertaining the position of the vertical plane of the axis of such bore when extended to the heel portion of the barrel and locating the zero mark for the rear sight at such point whereby the front and rear sights are in the same vertical plane with the axis of the bore at the muzzle end of the barrel.

3. An apparatus for properly locating the zero mark of the rear sight of a gun-barrel, comprising a plug adapted to fit and to be inserted in the muzzle end of a gun-barrel and to project therefrom and means supported by the projecting portion of such plug extending vertically and rearwardly by which the vertical plane of the axis of the bore of the muzzle end may be located on the rear portion of the barrel, substantially as shown.

4. In an apparatus of the class described means to ascertain the alinement of the bore of the muzzle end of a barrel, a member connected therewith adapted to support a straight edge and a straight edge member extending to the rear of and outside of the barrel, one edge of said straight-edge being adapted to be arranged in alinement with and in the same vertical plane with the axis of the bore of the muzzle end of the barrel and a marking member adapted to mark such line at the rear of the barrel.

5. In an apparatus for targeting gun barrels, the combination of a suitable support for a gun barrel, a rigid member adapted to enter and fit the bore at the muzzle end of a gun barrel and to extend in direct line therefrom, a member mounted, supported by and projecting vertically from the first member, a member rigidly secured to the latter member and adapted to extend to the rear portion of the barrel and anti-friction means carried by the supporting frame for supporting the rear portion of the barrel substantially as shown.

6. In an apparatus of the class described, the combination of a suitable support for rigidly supporting a gun barrel, means controlled by the wall of the bore at the muzzle end to ascertain the direction of the bore of the muzzle end of the barrel, and means, cooperating therewith and extending therefrom to locate the vertical plane of the axis of such direction at the rear portion of the barrel.

7 In an. apparatus of the class described the combination of a member adapted to en ter and bear against the wall of the bore of a gun barrel at its muzzle end, and means cooperating with and controlled by the first mentioned member to locate a point on the exterior of the rear portion of the barrel in the vertical plane of the axis of the bore of the muzzle end, substantially as shown.

ELWYN T. STEPHENS.

toptee at thie patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D 0."

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