US3303742A - Full ball and socket assembly - Google Patents

Description

Feb 1967 R. J. THIERRY ETAL 3,303,742

FULL BALL AND SOCKET ASSEMBLY Filed May 18, 1965 4 Sheets-Sheet l INVENTORS Eu'ber'i J ThiEI Ty 53 BY ZZZ @Wi y;

ATTO-RN EYS Feb. 14, 1967 R. J. THIERRY ETAL FULL BALL AND SOCKET ASSEMBLY 4 Sheets-Sheet 2 Filed May 18, 1965 ATTORNEYS j s R O T N E V m Feb. 14, 1967 J. THIERRY ETAL 3,303,742

FULL BALL AND SOCKET ASSEMBLY Filed May 18, 1965 4 Sheets-Sheet 5 ATTORNEYS Feh 14, 1967 R. J. THIERRY ETAL 3,303,742

FULL BALL AND SOCKET ASSEMBLY Filed May 18, 1965 4 Sheets-Sheet 4 INVENTORS RULE-r1 J-Thia1-1 y 5 Eph En [ll-in TV 11111.

ATTORNEYS 3,305,742 FULL BALL AND SU CKET ASSEMBLY Robert J. Thierry, Aver-iii Park, and Stephen C. Horvath, Troy, N.Y., assignors to the United States of America as represented by the Secretary of the Army Fiied May 18, 1965, Ser. No. 456,870 Claims. (Cl. 89-67) manufactured governmental royalty there- The invention described herein may be and used by or for the Government for purposes without the payment to us of any This invention relates to a ground mount for muzzleloading guns, such as mortars, and is more specifically directed to an improved ball and socket joint for coupling the gun to the mount.

In those mortars which are mounted on a stationary baseplate design-ed to lie on the ground, the required traverse of the firing tube in azimuth and elevation is generally provided by a ball and socket joint which serves to connect the firing tube to the baseplate. In this type of joint, the ball is ordinarily attached to or made an integral part of the free end of an arm extending rearwardly from the breech end of the firing tube While the socket is formed into the baseplate for rotatable reception of the ball. Although this design effectively provides the maneuverability required to rapidly adjust the aiming position of the firing tube in the event of a change in the location of the target, the various ball and socket joints heretofore utilized in mortars do not meet current military requirements.

For one thin, past experience with mortars of all sizes has clearly shown that the stability of the firing tube and the resulting accuracy of fire can be greatly improved by the utilization of a ball and socket joint in which the ball is of maximum diameter in order to minimize the shocks imparted to the baseplate by the recoil forces transmitted through the firing tube during the discharge of a projectile therefrom. However, up to now, the advantages obtained by an increase in the size of the ball have been virtually nullified by the accompanying increase in the length and width of the support arm required to support the ball. Obviously, any increase in the size and weight of the firing tube detracts from the ease of handling and the mobility which is so necessary in modern infantry weapons.

Accordingly, it is an object of this invention to provide an improved ball and socket joint for coupling the muzzle-loading firing tube of a mortar to a stationary baseplate without the necessity for any support arm for the ball.

It is a further object of this invention to provide a ball and socket joint as aforesaid which will permit a significant decrease in the length and weight of the firing tube and in the size of the baseplate.

Another object of the present invention lies in the provision of a ball and socket joint for a mortar wherein the interior of the ball may be utilized to house the firing mechanism.

In addition, since mortars are generally loaded from the muzzle end, any failure to fire due to defective ammunition will prevent further operation thereof until the unfired round can be removed from the firing tube. This can be accomplished in a rapid and safe manner by completely removing the firing tube from the baseplate and dumping the defective round in a protected area away from the mortar emplacement. However, considerable difficulty has been experienced in removing the ball from the socket with the required rapidity. For one thing, the need for retaining the ball in the socket against accidental or premature separation complicates the assembly and disassembly thereof. For example, where the socket is formed in separate halves secured to the baseplate by suitable locking means accessible from the exterior, the time required to unfasten and separate the halves is well beyond the acceptable limits which have been established for the safe disposal of defective ammunition.

In another attempt to retain the ball in the socket without undue interference with the ease of assembly and disassembly, the interior periphery of the socket is extended above the diametrical axis thereof and diameter of the ball is reduced along the cylindrical section encircling the exterior thereof to form a band with a slightly smaller transverse dimension than the distance across the open top of the socket. Thus, the ball will be retained in the socket in all positions of rotation except the one in which the diameter of the band coincides with the distance across the open end of the socket. While such structure provides the required rapidity of assembly and disassembly between the ball and the socket, the circumferential area occupied by the band reduces the available bearing surface of the ball to such extent that the increase in the unit stress on the bearing surface of the socket far outweighs the advantages gained by the simplicity of the means for retaining the ball in the socket. Furthermore, the necessity for a socket wall surface which extends above the diametrical axis thereof produces an undesirable increase in the overall weight of the mortar as well as in the cost of fabricating the joint.

It is, therefore, a further object of this invention to provide a ball and socket joint for a mortar wherein the ball is normally retained in the socket in the manner which does not require that the depth of the socket exceed the radial dimension thereof.

Still another object of this invention is to provide a ball and socket joint as aforesaid which is particularly adapted to resist the torque imparted thereto in the event the mortar utilizes a rifled firing tube.

Finally, it is a general object of this invention to pro vide a ball and socket structure for a mortar which will enable the firing tube thereof to be rapidly removed from the baseplate with a minimum of manipulation and without the use of tools.

It has been found that the foregoing objects can be achieved by a ball and socket joint in which the ball is formed as a hemispherical continuation of the breech end of the firing tube and is rotatably seated in a mating spheroidal socket formed into the baseplate. Instead of depending on the curvature of the entire socket wall to retain the ball therein, this is accomplished by a pair of blocks vertically mounted at diametrically opposed locations on the top of the socket walls in position to continue the spherical contour thereof for mating engagement with the similarly contoured peripheral surfaces on a pair of wing lugs projecting from opposite sides of the firing tube adjacent the breech end thereof. Since the spherical peripheries of the wing lugs are concentric with the hemispherical breech end of the firing tube, the latter can be rotated in the socket to provide azimuth or elevational adjustment or a combination of both. Such structure provides the required bearing surface contact between the ball and the socket without the necessity for the additional size and weight which would be created in the joint if the socket were enlarged to receive the entire peripheral surface of the ball.

Furthermore, the ball and socket joint of this invention is particularly adapted for the rapid removal of the firing tube from the baseplate. This is accomplished simply by elevating the tube to a vertical position and then rotating it about the vertical axis thereof in either direction to withdraw the wing lugs out from under the retaining blocks.

Further objects and advantages of the invention will be apparent from the following specification andthe accompanying drawings in which:

FIG. 1 is a side elevational view of a typical mortar provided with the ball and socket joint of the present invention;

FIG. 2 is an enlarged view of the joint sectioned to reveal the interior configurations of the ball and the socket and broken away in one area to show the tip of the firing p FIG. 3 is an enlarged top view of the socket portion of the baseplate with the firing tube removed;

FIG. 4 is a view similar to that of FIG. 3 but with the firing tube shown in a azimuth position with an elevation of substantially 45";

FIG. 5 is a top view similar to that of FIG. 4 but with the firing tube shown in the 90 vertical position thereof with the wing lugs rotated out from under the retaining blocks;

FIG. 6 is a vertical section taken along line 66 in FIG. 4 to show the engagement between the wing lugs and the retainer blocks;

FIG. 7 is a side View of the breech end of the firing tube; and

FIG. 8 is a rear view of the portion of the firing tube illustrated in FIG. 7.

While the ball and socket joint of the present invention may be utilized as a coupling between any two members subject to axial loads, it is particularly effective in a mortar which must be readily disassembled into separate units each of which can be handled by a single individual. As shown in FIG. 1, a typical mortar of this type consists of a baseplate 12 adapted to lie directly on the ground and provided with a centrally disposed socket 14 for rotatably receiving the correspondingly contoured breech end of a firing tube 16. Support for the muzzle end of firing tube 16 is preferably provided by a bipod 18 containing an elevating mechanism 21) operable by a' suitable handwheel 22 for rapid adjustment of tube 16 to any desired angle within the maximum and minimum limits of travel.

The breech end of firing tube 16 is formed as a hemispherical section 24 which is cylindrically extended forwardly, as indicated at 26 in FIG. 2, to provide a threaded interior 28 for engaging the correspondingly threaded end 30 of the cylindrical section of tube 16. An annular pocket 32 is provided within the interior of section 24 to form a centrally disposed housing 34 in which a firing pin 36 is threadably secured to protrude from the forward end thereof.

A generally rectangular wing lug 38 is integrally formed or suitably secured to the breech end of firing tube 16 at diametrically opposite locations thereon disposed at the junction of sections 24 and 26. As best shown in FIG. 8, the exterior periphery of each wing lug 38 is spherically contoured with a larger radius than the periphery of hemispherical section 24 but concentric therewith. A clearance angle 40 is provided downwardly along the rear face of each wing lug 38 for a purpose to be shown.

While basplate 12 need not be of any particular shape, economy of fabrication requires that socket 14 be replaceable therein. Accordingly, as best illustrated in FIG. 2, socket 14 is formed in a circular body 42 having a spheroidal underside and removably seated in a corresponding opening 44 centrally disposed in baseplate 12. Socket body 42 is retained against tilting in opening 44 by the circumferential rim of a circular plate 46 secured to the top of baseplate 12 by a plurality of radially disposed bolts 48. A resilient O-ring 50 is seated in a circumferential groove 52 provided in the exterior periphery of socket body 42 to prevent dirt entering opening 44.

The upper portion of socket body 42 is recessed to form a spherical zone 54 defining a circular wall'56 with a vertically curvilinear face 58 surrounding socket 14 but concentrically spaced therefrom to provide a circular track 60 for a purpose to be shown. Fixedly secured to the top of wall 56 at diametrically opposite locations thereon are a pair of arcuate retainer blocks 62 provided with spherical inner faces 64 coextensive with the curvilinear face 58 of wall 56. Although the spherical contours on retainer blocks 62 and on wing lugs 38 are radially equivalent, the peripheral extent of inner face 64 in both axial directions is greater than the corresponding dimensions along the exterior periphery of wing lug 38. Midway of blocks 62, a portion of track 60 is elevated, as indicated at 66, to extend the spherical contour of socket 14 to substantially the same height as the top of wall 56 in order to provide additional bearing surface for the hemispherical breech end of firing tube 16.

In the event the bore of firing tube 16 is rifled to increase the range of the projectiles fired therefrom, the resulting torque loads on tube 16 must be nullified or counteracted in order to maintain the required stability thereof during firing. This is accomplished by providing a projecting pin 68 on the breech end of firing tube 16 substantially midway of wing lugs 38 thereon and a rectangular slot 70 equal in width to the diameter of pin 68 intersecting socket 14 diametrically opposite elevated portion 66 at the rear thereof.

To assemble firing tube 16 to baseplate 12, the breech end of the former is first vertically lowered into socket 14 with wing lugs 38 angularly positioned to lie between retainer blocks 62. Then, tube 16 is rotated about the vertical axis thereof to bring wing lugs 38 thereon into mating contact with inner faces 64 of retainer blocks 62 and such rotation is continued until torque pin 68 is aligned for entry into rectangular slot 70. Thereupon, firing tube 16 may be lowered and rotated to the desired firing attitude.

Rotation of firing tube 16 in azimuth is limited by the contact of the sides with retaining blocks 62. However, this azimuth movement may be increased by the removal of the forward inner corner of each block 62 as indicated at 72. Although clearance angles 40 on wing lugs 38 prevent interference with track 60, depression of firing tube 16 in elevation is limited by the contact thereof with the rim of socket 14 along the forward portion thereof. Additional depression of tube 16 may be obtained by elongating the spherical contour of socket 14 in the direction of slot 70, as best shown at 74 in FIG. 3, to form a spheroidal contour. In order to achieve the benefits of this elongation of socket 14, a corresponding portion of the upper edge of wall 56 is forwardly beveled as best indicated at 76. In addition, track 60 is provided with shallow arcuate depressions 78 below each retaining block 62 to prevent interference with wing lugs 38 during elevation when firing tube 16 is adjusted to either limit of its azimuth range.

Thus, when the mortar is fired, the resulting recoil loading is distributed over the interior of socket 14 and the inner faces 64 of retaining blocks 62 with a contribution by elevated portion 66 in the lower elevations of tube 16. Any torque loading is counteracted by the contact of pin 68 on the walls of slot '71 Disassembly is rapidly effected by elevating firing tube 16 to the vertical position thereof in which torque pin 68 is withdrawn from slot 70 and then rotating tube 16 in either direction about the vertical axis thereof until wing lugs 38 clear retaining blocks 62. Thereupon, firing tube 16 is free to be lifted out of baseplate 12.

Thus, there is here provided a ball and socket joint which is particularly advantageous for use in mortars. The ability to utilize the breech end of the firing tube as the ball enables a substantial reduction in the length and weight thereof which benefits the loading of the ammunition as well as the transportability of the weapon. The bearing contact between the wing lugs and the retainer blocks permits a substantial reduction in the sizes of the ball and the socket without any corresponding sacrifice in the ability of the joint to withstand the forces encountered during firing of the mortar and prevent any instability of the firing tube which might reduce the accuracy of fire. Furthermore, the ball and socket design described herein is highly desirable in view of the minimum of manipulation involved in effecting the complete removal of the firing tube from the baseplate. This feature is particularly important in providing a maximum of safety when clearing the firing tube of any round which fails to fire. Another desirable feature of the ball and socket joint is the simplicity and economy involved in the fabrication thereof in any quantity due to the concentricity of the various spherical surfaces utilized therein.

The present invention has been described in detail above for the purpose of illustration only and is not intended to be limited by this description or otherwise except as defined by the scope of the appended claims.

We claim:

1. A ball and socket joint for a mortar having a baseplate and a firing tube adapted to be loaded from the muzzle end, comprising a hemispherical section coextensive with the exterior periphery of the firing tube to form the breech end thereof, a pair of wing lugs projecting from diametrically opposed locations on the exterior periphery of said firing tube breech end, the exterior peripheries of said wing lugs being spherically con-toured in concentric relation to said hemispherical breech end of the firing tube, a socket body in the baseplate having a spherical opening disposed for mating engagement with said firing tube breech end, and a pair of retaining blocks secured to diametrically opposed locations on said socket body and having spherically curved inner faces vertically coextensive with the interior periphery of said spherical socket opening for rotatable mating engagement with said exterior peripheries of said wing lugs whereby the firing tube is r-otatably seated in the baseplate for elevational and azimuth movement and is retained therein until said wing lugs are rotated out of contact with said retaining blocks.

2. The combination defined in claim 1 wherein the interior periphery at the forward end of said socket opening is intersected by a rectangular slot, and said firing tube breech end includes a projecting pin disposed substantially midway of said wing lugs thereon for entry into said slot in said socket opening in order to prevent rotation of the firing tube in response to any torque loads imparted to the firing tube during firing operation of the motar.

3. The combination defined in claim 1 wherein said spherical socket opening is forwardly elongated and the forward rim of said socket body is correspondingly beve ed to increase the elevational movement of the firing tube in the downward direction.

4. In a mortar having a baseplate and a cylindrical firing tube adjustably mounted thereon, a hemispherical section coextensive with the exterior cylindrical periphery of the firing tube to form a closed breech end, a firing pin threadably secured in said breech end of the firing tube, a pair of substantially rectangular wing lugs projecting outwardly from diametrically opposed locations on said firing tube breech end, said wing lugs each having a spherical exterior periphery radially greater than said firing tube hemispherical section but concentric therewith, a socket body releasably secured in the baseplate and having a centrally disposed spherical zonal recess defining a circular wall with a vertically spherical face, said body having a spherical socket concentric with said vertically spherical face but spaced therefrom to define an adjacent circular track, and a pair of retaining blocks extending upwardly from said socket body at diametrically opposed locations thereon, said blocks having spherically curved inner faces vertically coextensive with said spherical wall face whereby the combined surfaces thereof provide hearing engagement for said wing lugs during the elevation and azimuth movements of the firing tube.

5. The combination defined in claim 4 wherein the rearward portion of said circular track substantially midway of said retaining blocks is elevated to the height of said wall to continue the spherical contour of said socket for increasing the contact area for said hemispherical breech end of the firing tube.

References Cited by the Examiner UNITED STATES PATENTS 1,471,063 10/1923 Rognlie 89-37 2,194,849 3/1940 Denoix 894O 2,264,791 12/1941 Fries 8937 3,112,674 12/1963 Jasse 89-4O References Cited by the Applicant UNITED STATES PATENTS 2,599,565 6/ 1952 Lontz.

3,003,399 10/1961 Donner.

BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

S. C. BENTLEY, Assistant Examiner.

Claims (1)

1. A BALL AND SOCKET JOINT FOR A MORTAR HAVING A BASEPLATE AND A FIRING TUBE ADAPTED TO BE LOADED FROM THE MUZZLE END, COMPRISING A HEMISPHERICAL SECTION COEXTENSIVE WITH THE EXTERIOR PERIPHERY OF THE FIRING TUBE TO FORM THE BREECH END THEREOF, A PAIR OF WING LUGS PROJECTING FROM DIAMETRICALLY OPPOSED LOCATIONS ON THE EXTERIOR PERIPHERY OF SAID FIRING TUBE BREECH END, THE EXTERIOR PERIPHERIES OF SAID WING LUGS BEING SPHERICALLY CONTOURED IN CONCENTRIC RELATION TO SAID HEMISPHERICAL BREECH END OF THE FIRING TUBE, A SOCKET BODY IN THE BASEPLATE HAVING A SPHERICAL OPENING DISPOSED FOR MATING ENGAGEMENT WITH SAID FIRING TUBE BREECH END, AND A PAIR OF RETAINING BLOCKS SECURED TO DIAMETRICALLY OPPOSED LOCATIONS ON SAID SOCKET BODY AND HAVING SPHERICALLY CURVED INNER FACES VERTICALLY COEXTENSIVE WITH THE INTERIOR PERIPHERY OF SAID SPHERICAL SOCKET OPENING FOR ROTATABLE MATING ENGAGEMENT WITH SAID EXTERIOR PERIPHERIES OF SAID WING LUGS WHEREBY THE FIRING TUBE IS ROTATABLY SEATED IN THE BASEPLATE FOR ELEVATIONAL AND AZIMUTH MOVEMENT AND IS RETAINED THEREIN UNTIL SAID WING LUGS ARE ROTATED OUT OF CONTACT WITH SAID RETAINING BLOCKS.

Images