US2465937A

US2465937A - Gun mount assembly

Info

Publication number: US2465937A
Application number: US568620A
Authority: US
Inventors: Sheleski Joseph
Original assignee: Glenn L Martin Co
Current assignee: Glenn L Martin Co
Priority date: 1944-12-18
Filing date: 1944-12-18
Publication date: 1949-03-29
Anticipated expiration: 1966-03-29

Description

March 29, 1949. .1. SHELESKI GUN MOUNT A SS EMBLY 2 Sheets-Sheet 1 Filed Dec. 18, 1944 I'll/Ill!!!" INVENTOR. ph Shelesk Jose i (fwd/U.

ATTORNEY March 29, 1949. J. SHELESKI 2,465,937

GUN MOUNT ASSEMBLY Filed Dec. l8, 1944 '2 Sheets-Sheet 2 IN V EN TOR.

ATTORNEY Patented Mar. 29, 1949 STAT ES GUN MOUNT ASSEMBLY Application December 18, 1944, Serial No. 568,620

8 Claims. 1

My invention relates to a gun mount assembly, and more particularly to an improved counterpoise for a gun or the like.

Oneof the prime requisites in modern gunnery is the unrestricted, instantaneous movement of the gun to any desired position. This is notably in aircraft guns where opposing objects may come from any conceivable angle or direction. It is, for this reason, important that the handling of the gun be made as. simple and convenient as possible. One major factor is the unbalanced moment of a gun which results where the gun is pivotally mounted with its center of gravity at a point rearward of the pivot. This type of mounting is necessitated in many present day aircraft installations because of the need for having the operative parts of the gun confined Within the main aircraft enclosure so that they will be readily accessible for repair or replacement in cases of emergency. Thus, if the conventional gun were to be pivoted at its center of gravity the ammunition feed would be located exteriorly of the main portion of the plane. Not only would this necessitate an enlarged turret, but it would also mean any repairs or emergency handling of the gun in flight would be undertaken in freezing temperatures and in circumstances of extreme hardship. Consequently such guns are currently mounted with an unbalanced moment. This unbalanced moment is at its greatest when the gun is in its horizontal position, and said moment decreases as the gun approaches the maximum of its range either above or below the horizontal.

As a result of this situation the gunner has, under conditions characteristic of the prior art, a variable force which must be overcome in order to bring the gun to bear on a new target. In some instances up or down movement will require an increasing counterbalancing force; in others, a decreasing force. The variability of this required force will frequently cause a time lag in centering the gun upon the target and the manual effort of the gunner required to compensate for the unbalance contributes to the fatigue of the gunner. It is a purpose of my invention to produce a counterbalance mechanism whereby the unbalanced moment of the gun due to its relative center of gravity and pivot location will be compensated.

It is further purpose of my invention to provide a counterbalance mechanism for a gun or the-like whereby the unbalanced moment of the gun will be opposed by a counterbalancing force which is at a mean value when the -gun is in a horizontal position, and which decreases asthe gun departs from the horizontal in either direction.

A. further purpose is to provide counterbalancing means for a gun mounted for movement on a pivot and wherein the center of gravity of said gun is spaced from the pivot and the counteralancing means includes a spring adapted to oppose the force of gravity acting on said gun, and wherein link means connect the spring and gun mount so that the eiiect of said spring varies with the angular displacement of the gun on its pivot.

The foregoing and other objects relating to economics in manufacture and ease of operation will become apparent from the following description, and from the drawings wherein:

Figure 1 is an elevation of a gun mount includ ing my counterbalancing mechanism with the gun in the horizontal position;

Figure 2 is a sectional view taken on line 2 of Figure l; and

Figure 3 is a view similar to Figure 1 showing the gun in a raised position.

The barrel l of a conventional gun assembly 8 is inserted through a sleeve 9 adapted to slidably receive the barrel.

The gun assembly 8 is securely clamped to the sleeve Q by semi-circular flanged members lll--l 9a which embrace abutting flanges on the sleeve 9 and assembly 8.

The barrel receiver sleeve 9 is rotatably carried on an azimuth mounting yoke H by means of a pair of horizontal gimbal pins l2 mounted exteriorly of the sleeve and received by apertures in the mounting yoke H. The yoke ll comprises a pair of spaced vertical arms Ha mounted on a cylir'idrical post l3. By means of this construction the gun l is rotatable in a vertical plane about the pins l2 and within the arms i la of the mountingyoke H. The cylindrical post I3 of the yoke H is received by a hollow mounting base M in which it is adapted for rotating movement about its vertical axis. A horizontal groove l5 about the circumference of the post is receives the end of a lock screw liia by which the post is rotatably secured within the mounting base M.

To effect counterbalancing an inner sleeve It is slidably fitted within the forward end of sleeve 9, and is provided at its telescopic connection therewith with a pair of outwardly extending trunnion lugs H which are received by a slot l8 formed 1' the end of the sleeve fl. A coil spring l9 surrounds the inner sleeve l6 and the forward end'of sleeve 9 and is compressed between a flange or boss 20, fixed to and extending outwardly from the surface of sleeve 9 and a flange 2| of a spring adjusting nut 22 which is assembled with the outer end of the inner sleeve i 6, as by a threaded connection.

The sleeve I6 is operably connected to the mounting yoke l! by a pair of articulating links 23 which are secured at one end to the trunnion lugs H and at the other end to a pair of horizontal gimbal pins 2! projecting toward each other within the mounting yoke H at a point below and rearwardly of the pivot l2.

A spherical shield 25 partially surrounds the elevation mount assembly to provide a weather seal protecting the gunner from the air which would otherwise enter the gun slot in the turret window 26.

The center of gravity of the unbalanced gun assembly 'l8, as it rotates about the pivot I2, is at some point CG, rearward of the pivot due to the mass of the loading and firing mechanism. The force of gravity therefore gives to the gun at all times during its rotation a. turning moment which is at its maximum with the gun in the horizontal position (Figure 1) where the perpendicular distance from the vertical plane of pivot l2 to the CG is the greatest. This turning moment accordingly decreases as the gun is rotated either up or down from the horizontal, until it reaches its minimum at the positions of maximum up or down fire.

An effective counterbalancing moment must, therefore, be developed when the gun is in the horizontal position, that can be proportionately decreased with the corresponding departure of the gun from the horizontal.

This I have accomplished by the positioning of and relationship established between the spring iii, the links 23, and the mounting yoke H; and by the proper positioning of the gimbal pins 24 with relation to the pivot l2. The counterbalancing force of spring l9 while suflicient to balance statically the gun in the horibontal position, attains a mean or intermediate value by reason of the action of links 23 arranged to transmit the urge of spring I9 to gimbal pins 24 of the mounting yoke ll. As the gun rotates in elevation about its pivot the links 23 urge the sliding sleeve it either toward or from the sleeve 9, in the former case loading the spring l9 by .compressing it between the flanges 2i and 2|, and in the latter case unloading the spring. As the gun rotates in elevation the position of the links 23 varies with relation to the pivot l2, thereby either decreasing or increasing the perpendicular distance from the pivot 12 to the line of force effective between the spring and pivot 24 with a consequent decrease or increase in the moment arm of the counterbalancing force. Thus, when the gun barrel 1 is raised (see Figure 2), the compression of spring I9 is increased by reason of the eccentric anchorage of links 23 even though the moment arm of the CG of the gun is shortened. In this manner, the spring loading is increased in proportion to the elevation of the gun muzzle so as to provide a restoring force which aids the gunner in returning the gun to a horizontal position; correspondingly, when the barrel is lowered, the weight of the gun acting through its CG aids the gunner in returning the gun to the horizontal position as best illustrated in Figure 1. With the gun in a depressed position, the lighter spring restoring force is attained by reason of the arrangement of the links 23 which causes the spring tension to be reduced to a value less than the mean value attained when the gun is in a horizontal position. The links 23 and the gimbal pins 24 are so positioned that the change in distance from the pivot varies to produce an approximate sinusoidal variation in the counterbalancing moment as the gun varies from the horizontal in either direction; a variation equal at all times to the corresponding variation in the unbalanced moment of the gun.

In this manner, therefore, I obtain a counterbalanced gun mount whereby the unbalanced moment of the gun and the counterbalancing moment of the spring will at all times be approximately equal. Guns of different weights may be counterbalanced by simple adjustment of the nut 22 to make the necessary allowances.

While I have described my counterbalance mechanism as used with a gun, it is obvious that it would be useful in any number of situations Where an unbalanced moment prevailed. My invention is not, therefore, to be construed as restricted to use with a gun, or otherwise than as expressed in the following claims.

I claim:

1. Counterbalancing means for a gun having a barrel and firing assembly mounted for rotary movement on a pivot carried by support means, the center of gravity of said gun being at a point spaced from said pivot, said counterbalancing means comprising in combination a sleeve slidably mounted on the barrel of said gun, spring means in cooperative arrangement with said sleeve whereby movement of said sleeve will either increase or decrease the force of said spring, pins mounted on said support means at ape-int spaced from said pivot and link means connecting said sleeve to said pins whereby rotation of said gun creates a counterbalancing moment in all positions equal to the unbalanced moment of said gun.

2. The combination with a gun having a barrel and firing assembly mounted for vertical rotary movement on a pivot carried by support means, the center of gravity of said gun being at a point rearward of said pivot of a sleeve releasably mounted on the barrel of said gun, a second sleeve in co-axial, slidable relation with said first sleeve, spring means in cooperative arrangement with second sleeve whereby movement of said second sleeve will either increase or decrease the force of said spring, pins mounted on said support means at a point rearward of said pivot, and link means connecting said second sleeve to said pins whereby vertical rotation of the gun creates a counterbalancing moment in all positions equal to the unbalanced moment of the gun.

3, The combination with a gun having a barrel and firing assembly mounted for vertical rotary movement on a pivot carried by support means, said gun being mounted with an unbalanced moment of force due to its center of gravity being at a point spaced from said pivot, of counterbalancing means for said gun, said counterbalancing means comprising a pair of sleeves mounted on the barrel of said gun, said sleeves being in slidable relation to each other, spring means in cooperative arrangement between said sleeves whereby movement of one of said sleeves relative to the other varies the tension of said spring, a pin mounted on said support means, and link means connecting said one sleeve with said pin, whereby movement of said gun will vary the position of said sleeve and the force exerted by said spring.

4. Counterbalancing means for a gun having a barrel portion mounted for rotary movement on a pivot carried by support means, said gun being mounted with an unbalanced moment of force, due to its center of gravity being at a point spaced from said pivot, said counterbalancing means comprising a spring encircling the barrel of said gun, a pin mounted on said support means at a point rearward of said pivot, and link means connecting said spring means to said pin whereby a change in position of said gun barrel relative to said pivot is transmitted to said spring creating a counterbalancing moment in all positions equal to the unbalanced moment of said gun.

5. Counterbalancing means for a gun mounted for rotary movement on a pivot .carried by support means, said gun being mounted with an unbalanced moment of force due to its center of gravity being at a point spaced rearward from said pivot, said counterbalancing means comprising, in combination, spring means encircling said barrel and adapted to counteract the force of gravity on said gun, a pin mounted on said support means, and link means connecting said spring means to said pin adapted for movement relative to said pivot to vary the perpendicular distance from the pivot to the line of force of said link means as the gun is rotated, whereby the counterbalancing moment will in all positions of said gun be equal to the unbalanced moment.

6. In a gun mount, a barrel receiver pivoted for elevating movement in a support with a fixed abutment carried by the receiver and positioned normal to the axial centerline of said receiver, means to balance a gun carried by said receiver comprising a slidable sleeve co-axial of the gun barrel a second abutment carried by the sleeve and adapted for axial movement along the barrel relative to said fixed abutment carried by the receiver, spring means between said abutments adapted to urge said sleeve away from the receiver, a pin mounted on said support eccentric of the elevating pivot and a link connecting said slidable sleeve and said pin whereby movement of the gun about said elevating pivot varies the tension of the spring and the efiective lever arm of the spring force.

7. In a gun mount, a barrel received pivoted for elevating movement in a support, means to balance a. gun carried by said receiver comprising a carrier sleeve, a boss fixed to and projecting from the carrier sleeve, a second sleeve carried by said carrier sleeve for slidable movement toward and away from the receiver, a spring arranged between the boss and the end of the second sleeve remote from the carrier to urge said second sleeve away from the carrier, a pin fixed to said support eccentric of the elevating pivot, and a link connecting said second sleeve and said pin whereby movement of the gun about said elevating pivot varies the tension of the spring and the eiiective length of the lever arm through which the spring acts on the gun.

8. Counterbalanoing means for a gun mounted for rotary movement on a pivot carried by support means, said gun being mounted with an unbalanced moment of force, due to its center of gravity being at a point spaced from said pivot, said counterbalancing means comprising, in combination, spring means associated with said gun and adapted to exert spring urge longitudinally of the gun to counteract the force of the gravity in said gun, a pin mounted on said support means, and link means connecting said spring means to said pin adapted to move around said pin and to vary the force of said spring means as the gun rotates on its pivot, whereby the counterbalancing moment will in all positions of said gun be equal to the unbalanced moment.

JOSEPH SHELESKI.

REFERENCES CITED The following references are of record in the file of this patent: