US2372568A

US2372568A - Gun

Info

Publication number: US2372568A
Application number: US511017A
Authority: US
Inventors: Jesse M Grigg
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-11-20
Filing date: 1943-11-20
Publication date: 1945-03-27
Anticipated expiration: 1962-03-27

Description

J. M. GRIGG March 27, 1945.

GUN

Filed Nov. 20, 1943 Jesse M57199 Patented Mar. 27, 1945 UNITED STATES PATENT OFFICE GUN Jesse M. Grigg, Chicago, Ill.

Application November 20, 1943, Serial No. 511,017

Claims.

This invention relates to firearms generally, and is in the nature of an improvement on the gun shown, described and claimed in my prior application, Serial No. 393,063, filed May 12, 1941, now Patent No. 2,339,331 dated January 18, 1944.

One of the objects of this invention is the production of a firearm of greatly improved accuracy; another object is the production of novel means to minimize the normal interference and reactions of the marksmans body upon the firearm, which reaction reduces the accuracy with which the shots are placed in a target; another object is the production of a firearm having a high degree of accuracy and relatively light weight, thereby resulting in a saving of the marksmans physical energy.

Another object is the production of a firearm in which distortion of the barrel due to temperature changes, stock warpage, heating of the barrel due to firing the firearm is practically eliminated, and another object is the production of a firearm in which the barrel is so mounted on the stock that it is free to vibrate in its natural period during firing, and to provide means to maintain consistency of the vibrations during successive firing of the firearm with the same kind of ammunition.

A study of the mechanics involved in the aiming and shooting of rifled shoulder arms will disclose that the accurate and consistent placing of a missile in a target or other object is dependent on several related factors, and it is these factors which exercise a considerable influence on the grouping of shots and the skill of the marksman. If it were possible to maintain the gun barrel aimed in a given direction throughout the period from powder ignition, to the discharge of the missile or bullet from the barrel, regardless of the forces tending to deflect the barrel from such direction, the accuracy and consistency of marksmanship would be considerably improved.

However, in a rifle when discharged under ordinary firing conditions the barrel is subjected to a number of forces that affect and alter the position of the barrel with respect to the target and therefore, the direction taken by the bullet as it leaves the muzzle. The forces of combustion are primarily exerted on the barrel in two ways, one is a backward thrust or recoil which, owing to the fact that the center of gravity lies below the bore axis, normally exerts an upward torque about the center of percussion. The other is a downward torque or a down thrust exerted mainly during the period of combustion change, this down thrust probably having its .origin in the fact that the powder charge initially lies on the bottom of the cartridge case and tends to hug the bottom of the bore 'as the burning and unburned grains are swept along by the blast.

It will be apparent that as the gun barrel is relatively flexible the resultants of these forces will cause bending of the barrel. The initial bending of the central portion of the barrel is downward and is opposed not only by the upward torque and barrel resiliency but in conventional designed guns, also by the forestock, and as the latter is supported by the hand of the person firing the gun such bending is opposed by such support as well. This downward bending continues until the diminishing applied force is exceeded by the opposing upward force. The latter, supplemented by the kinetic energy in the barrel due to such downward bending and the action of the marksmans hand and wrist, then proceeds to reverse the bending curve. Therefore, as the bullet leaves on a line tangent to the bore axis at the muzzle, and as this tangent itself is turning with a slight angular motion, it is obvious that the final direction of the bullet as it leaves the muzzle is not that in which the bore axis was originally aimed. Again, as there is a transmitted reaction between the barrel and the marksmans hand, arm, etc., and as further it is humanly impossible for the marksman to assume the same hold and firing position each time, this transmitted reaction is bound to change. With all, it results in various manners of bend, and in various directions of bullet departure. In the language of the marksman, the rifle may either change its zero by small increments with repeated firing, or it may unexpectedly throw an outright wild shot.

In accordance with the laws of physics, a given barrel has an inherent period of vibration which may be readily determined by experiment or calculation. This vibratory movement is in the nature of standing waves, of a definite wave length, with accompanying nodes or points of substantially no barrel movement at two or more points along the barrel. In actual practice, though the movement is not a free but a forced oscillation, these nodes follow at substantially corresponding points along the bore axis.

Another object is to fix a nodal point along the length of the barrel about which the axis of the bore of the barrel flexes or vibrates, and whereby the flexing or vibrations will be consistent about the same nodal point each time the firearm is fired, using the same kind of ammunition, thereby making it possible for the marksman to obtain greater accuracy in placing his shots.

Another object is to provide a more rigid mounting for the barrel at a nodal point, however, having resilient means to space the barrel from the stock and permit vibration thereof as well as longitudinal movement relative to the stock, caused by expansion and contraction of the barrel.

With these and other objects and advantages in view this invention consists in the several novel features hereinafter fully set forth and claimed.

The invention is clearly illustrated in the draw- 7 ing accompanying this specification in which:

Fig. l is a side elevation of a rifle embodying a simple form of the present invention;

Fig. 2 is a, fragmental detail side elevation illustrating the present barrel mounting means;

Fig. 3 is a detail fragmental vertical longitudinal section taken on the line 33 of Fig. 4;

Fig. 4 is an end elevation of the rifle;

Fig. 5 is a detail vertical cross section taken lustrative of one embodiment of the invention,

the reference character H designates the barrel of the gun and is of the usual construction rigidly secured at its breech to the receiver l2 which is likewise of general construction.

I2 is rigidly secured to the stock l3 a by screws I 4, l5 positioned at convenient places underneath the receiver thus rigidly securin the same to the stock.

The forestock H5 is provided with a longitudinally extending groove H in its upper edge to receive the barrel and a clearance space Ila is provided between the barrel and the forestock to permit flexing of the barrel when the gun is fired and to permit free longitudinal movement of the barrel relative to the stock due to expansion and contraction of the barrel.

Rigidly secured to the forestock at its forward end as by screws 18 is a trough-like barrel mounting member 19. The latter is preferably of uniform thickness throughout and is let into a recess I'Ib formed at the forward end of the forestock so that its inner or concave face may be flush with the concave face of the groove H in order that the clearance space between the barrel and its mounting I9 is maintained. It is desirable that the mounting 19 be rigidly fastened to the forestock and for this purpose I have shown several screws 18 for connecting the mounting with the fa-restock. The heads of the screws are'cou'n'tersunk in the mounting so as not to interfere with the-free longitudinal and flexing movement of the barrel relative to the forestock.

The mounting member projects slightly beyond the forward end of the 'forestock and'is formed with two laterally projecting lugs 20 at its upper edges and these lugs are bored and tapped for the reception of screws 2!. The ends of the lugs project slightly beyond the end edge of the body of the mounting member, and se- The receiver v cured to the end faces of said lugs by the screws 2| is a bifurcated or yoke-like resilient barrel spacing member 22. The upper edge of said member is concave and coincides generally with the concave upper face of the mounting member so as to leave clearance space between the barrel and the spacing member. The latter may be formed with laterally extending ears 23 at its upper end that register with the lugs 20 of the mounting member. As above stated the lugs project slightly beyond the forward edge of the mounting member thereby providing a clearance space :24 between the spacing member and front edge of the mounting member in which clearance space the body portion of the spacing member is free to flex or vibrate as a result of expansion or contraction of the barrel or any vibratory movements thereof which are induced when the gun is fired.

Desirably the spacing member is formed from a piece of resilient metal such as spring steel and it is provided with mean for securement to the barrel. As shown it is formed with an apertured tongue 25 which projects from'the lower edge of the body portion of the spacing member and is bent forwardly to lie in a direction paralleling the barrel but spaced downwardly therefrom. A block or Washer 28 having a concave upper face is interposed between the barrel and tongue and a screw 21 extends upward through the aperture in the tongue and through an aperture in the block or Washer and is 'threadedly secured in the lower part of the barrel. The

thickness of the block or washer is such that when the parts are secured together the block supports and spaces'the barrel above the groove in the forestock and mounting so as to leave a clearance space 'therebetween. Desirably lock washers 28 are interposed under the heads of the screws 2| and 21 to prevent accidental unscrewing of the screws. The screw holes in the ears 23 and tongue 25 of the spacin member 22 are slightly oversized to permit of slight adjustment of the spacing member with respect to the mounting member and the barrel. The point of attachment of the screw 2'! to the barrel is approximately midway between its muzzle and breech, namely, at a nodal point of the vibrating Wave movement of the barrel as induced during firing of the firearm.

Inasmuch as the spacing member is constructed from resilient metal it is free to flex or vibrate upon its places of 'securement to the mounting member and thereby permit the barrel to vibrate or flex in a vertical plane. By properly locating the point of attachment of the screw 21 to the barrel the vibrating wave movements of the barrel as induced during firing of the gun are always consistent thereby providing for extremeaccuracy in placing the shot in a given target, furthermore, the resilient spacing member permits of longitudinal movement of the barrel relative 'to the forestock due to expansion or contraction of the barrel.

In Fig. 8 I have illustrated diagrammatically the type of waves created in the barrel. In this view the line AA represents the bore axis, b represents the point of attachment of the barrel to the receiver and 0 represents the point at which the screw 21 is secured in the barrel and fixes a nodal point for the waves. The reference characters at, e designate other nodal points in the waves. From my experiments I have found that the nodal point d is located at a point distant from the muzzle of the barrel, which is approximately one tenth of the distance-between the muzzle and place of securement of the barrel in the breech; the point e is located at a point distant from the place of securement of its barrel in the breech which is approximately one"- vious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence, I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combina tion of the parts herein shown and described or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. In a firearm the combination of a barrel rigidly mounted at its breech on a gunstock, a forestock extending along a portion of the barrel with a clearance space between the barrel'and fdrestockya trough-like barrel mounting mem-; ber extending parallel with and rigidly secured to the forestock in a groove adjacent the barrel with a clearance space between the barrel and mounting member, a resilient bifurcated barrel spacing member aligned with said mounting member with its extremities rigidly secured thereto and being free to flex below said places of securement, and means to rigidly fasten said barrel spacing member to the barrel approximately midway between its muzzle and breech.

2. In a firearm the combination of a barrel rigidly mounted at its breech on a gunstock, a longitudinally grooved forestocl-r. extending. along a portion of the barrel with a clearance space between the barrel and forestock, a trough-like barrel mounting member extending parallel with and rigidly secured to the forestock with its upper face substantially flush with the face of the groove of the forestock, a resilient bifurcated barrel spacing member with its extremities rigidly secured to one end of the mounting member and depending from said places of securement, and means to rigidly secure the depending portion of the barrel spacing member to the barrel at a point approximately midway between its muzzle and breech, the body of said barrel spacing member being free to flex below said places of securement to permit longitudinal expanding and contracting movements of the barrel relative to the forestock and to permit vibration of the barrel as induced during the firing of the firearm.

3. In a firearm the combination of a barrel ri idly mounted at its breech on a gunstock, a forestock extending along a portion of the barrel with a clearance space betweenv the barrel and forestock, a trough-like barrel mounting member extending parallel with and rigidly secured to the forestock with a clearance space between the barrel and mounting member, a resilient bifurcated barrel spacing member aligned with said mounting member with its extremities rigidly secured thereto and being free to flex below said places of securement, and means to rigidly fasten said barrel spacing member to the barrel approximately at a nodal point of the vibration wave movements of the barrel which divide the barrel into two sections of equal length.

4. In a firearm the combination of a barrel rigidly mounted at its breech on a gunstock, a longitudinally grooved forestock extending along a portion of the barrel with a clearance space between the barrel and forestock, a trough-like barrel mounting member extending parallel withand rigidly secured to the forestock with its upper face substantially flush with the face of the groove thereof, a barrel spacing member aligned with said mounting member with its extremities rigidly secured thereto and its body portion'depending from said places of securement and free Having thus described my invention, it is oblo' to flex below said places of securement, a spacing block carried by said spacing member and means to rigidly secure said spacing member and block to the barrel at a point approximately midway between its muzzle and breech.

5. In a firearm the combination of a barrel rigidly? mounted at its breech on a gunstock, a longitudinally grooved forestock extending along a portion of the barrel with a clearance space between the barrel and forestock, a trough-like barrel mounting member extending parallel with and rigidly secured to the forestock with its upvper face substantially flush with the face of the groove thereof, saidv mounting member being formed with a pair of oppositely disposed lugs which project slightly beyond the end edge of the mounting member, a resilient yoke-like barrel spacing member aligned with said mounting member with its extremities rigidly secured to said lugs and its body portion depending from said places of securement and free to flex below said places of securement, a spacing block carried by said spacing member and means to rigidly secure said spacing member and block to the barrel at a point approximately midway between its muzzle and breech.

6. In a firearm the combination of a barrel rigidly mounted at its breech on a gunstock, a longitudinally grooved forestock extending along a portion of the barrel with a clearance space between the barrel and forestock, a trough-like mounting member extending parallel with and rigidly secured to the forestock with its upper face substantially flush with the face of the groove thereof, a resilient yoke-like barrel spacing member aligned with said mounting member with its extremities rigidly secured thereto and its body portion depending from said places of securement and free to flex below said places of securement, said spacing member having a forwardly extending tongue, a spacing block carried by the tongue of said spacing member and means to rigidly secure said spacing member and block to the barrel at a point approximately midway between its muzzle and breech.

'7. In a firearm the combination of a barrel rigidly mounted at its breech on a gunstock, a longitudinally grooved forestock extending along a portion of the barrel with a clearance space between the barrel and forestock, a trough-like barrel mounting member extending parallel with and rigidly secured to the forestock with its upper face substantially flush with the face of the groove thereof, a resilient yoke-like barrel spacing member aligned with said mounting member with its extremities rigidly secured thereto and its body portion depending from said places of securement and free to flex below said places of securement, said spacing member having a forwardly extending tongue, a spacing block carried by the tongue of said spacing member and means to rigidly securesaid spacing member and block to the barrel at a point approxi* mately at a nodal point of the vibrating wave movements of the barrel which divide the barrel into two sections of equal length.

8. In afirearm the combination of a barrel rigidly mounted at its breech ona gunstock, a 'fOIBStOCk extending along a portion of the barrel with a clearance space between the barrel and forestook, a trough-like barrel mountin member rigidly secured to the forestock with a clearance space between the barrel and mounting member, and a resilient yoke-like barrel spacing member aligned with said mounting member with its extremities rigidly secured thereto and having a forwardly extending tongue rigidly secured to the barrel approximately at the nodal point of the vibratory wave movements of the barrel which divide the barrel into two sections of equal length.

9. In va firearm the combination of a barrel rigidly mounted at its breech on a gunstock, a forestock extending along a portion of the barrel with a clearance space between the barrel and forestock, a trough-like barrel mounting member rigidly secured to the forestock with a clearance space between the barrel and mounting member, a resilient. yoke-like barrel spacing member having its extremities rigidly secured to the mounting member atthe forward edge thereof and there being a clearance space between the body portion of the barrel spacing member and the adjacent end of the barrel mounting member to permit flexing of the body portion of said spacing member, the latter havingaforwardly projecting barrel supporting part rigidly secured to the barrel approximately midway between its muzzle and breech.

10. In a firearm the combination of a barrel rigidly mounted at its breech on a gunstock, a forestock extending along a portion of the barrel with a clearance space between the barrel and forestock, a trough-like barrel mounting member rigidly secured to the forestock with a clearance space between the barrel and mounting member, a resilient yoke-like barrel smoing member having its extremities rigidly ae- Jeured to the mounting member at the forward edge thereof and there being a clearance space between the body portion of the barrel Spacing member and the adjacent end of the barrel mounting member to permit. flexing of the body portion of said spacing member, the latter having a forwardly projecting tongue, and a block interposed between .the barrel and tongue rigidly secured to the barrel and tongue approximately midway between the muzzle and breech of the barrel.

JESSE M. GRIGG.