US2694342A - Base-plate device for mortars and other guns - Google Patents

Description

BASE-PLATE DEVICE FOR MORTARS AND OTHER GUNS Filed July 27, 1949 Nov. 16, 1954 A. Y. CANONNE 4 Sheets-Sheet l m l z/v 70R: %5[A X14 6 (Imam/VL Nov. 16, 1954 A. Y. CANONNE 2,694,342

BASE-PLATE DEVICE FOR MORTARS AND OTHER GUNS Filed July 27, 1949 4 Sheets-Sheet 2 NOV. 16, 1954 QANQNNE 2,694,342

BASEPLATE DEVICE FOR MORTARS AND OTHER GUNS 4 Shee ts-Sheet 3 Filed July 27, 1949 MhXMW Arr iv Nov. 16, 1954 A. Y. CANONNE 2,694,342

BASE-PLATE DEVICE FOR MORTARS AND OTHER GUNS Filed July 27, 1.949 4 Sheets-Sheet 4 Fig. 16

Fig.1

Afr-yr United States Patent flfiice 2,694,342 Patented Nov. 16, 1954 BASE-PLATE DEVICEFOR YMORTARS AND OTHER GUNS Abel Yves Canonne, Paris, France, assignor to Etabli'ssemerits Edgar Brandt, PansgFi-ance, 'a- French' company Application -July' 27, 1949, Serial No. 107,011

Claims. priority, application France August 4, 1948 2 Claims. C11 89- 37) A The present invention relates to ground plates or anchoring devices for mortars, mihe-throwers and other similar guns.

The invention has for its object to provide a ground plate device of a simple construction by means of which the gun maybe set-in firing position very rapidly, on all grounds without any earthwork'under all azimuths and varying elevations, an efiicie'nt anchoring'of said plate in the ground, its-perfect balance and its-stability being secured irrespectivelyof thenature of the ground and of the pointingof the .gun both in azimuth and elevation.

In the accompanying drawings, given only by way of example:

Fig. 1 is a diametral sectional view, along line 1'1 of Fig. 2, showing an anchoring device in accordance with the invention.

Fig. 2 is a plan view of the same.

Fig. 3 is a cross-sectional view along line 33 of-Fig. 1.

Fig. 4 is a partial inverted plan view of the same.

Fig. 5 is a diagrammatical view, showing a mortar in position on the anchoring device.

Fig. 6 is a sectio'nal'view'showin'g, along line-6 -'6 of Fig. 7, another construction of ball-joint forthe ground late. p Fig. 7 is a plan view corresponding to Figi6.

Fig. 8 is a cross-sectional view, alongline 88 of Pi 6.

ig. 9 is a perspective view showing a gun in position on an anchoring device comprising a plurality" of ground lates.

p Fig. 10 is a diametral sectional view on an'enlarged scale, along line 1l)10 of Fig. 11.

"Fig. 11 is a plan view corresponding to Fig. 10.

Figs. 12 and 13 are partial sectional viewsalong lines 1212 and 13-13 respectively of Fig. ll but on an enlarged scale.

Figs. 14, and 16 show "diagrammatically further embodiments of the anchoring device in accordance with the invention.

In the example of execution shown in Figs. 1 to 4, the anchoring device comprises apla'ne metal base plate 1 'of circularshape which is shown in a horizontal position and whose axis is shown at AA. The plate is provided at itsperiphery with a depending flange or skirt 2 and an operating handle '21 is secured on the upper face of said plate. Around a central hole in said plate, is welded the upper flaring portion 14 of a vertical socket member 5 which'extends downwardly and is provided with'a pointed end 15 locatedon axis A--A. The angle of the inner conical wall of said "exte'nsionl t is preferably about 90.

The lower part '7 of-the ca'vity'or recess in socket 5 has a hemispherical wall 9 having'its centre at O, on axis AA, below the'base plate 1. Above thel'part 7, the socket has an annular groove 10 which facilitates the machining, when member 5 is obtained by a turning operation. Above said groove, the inner wall of the socket comprises two cylindrical parts '11 and two flat parts12. In said flat parts are provided two hollow hemispherical surfaces 13 in spherical alignment with the lower hemispherical surface 9.

On the lower face of baseplate l'are welded's'i'x vertical fins 16 forming anchoring elements arranged radially at 60 fromeach other. The inner edge of each fin is in contact with the central socket 5 and its lower tree edge comprises two curved parts 17 and Informing an intermediate pointed part 19. Points 19of the fins are arranged alternately in'two planes BB and CC parallel to and differently spaced from the plate 1. In a construction in which the base plate 1 has a diameter of about thirty-centimeters, the center 0 of the socket may be about three centimeters below the upper'face of plate 1 and the two sets-of points 19 may be respectively about twelve and nine centimeters below said upper face.

The fins 15 are further connected to each other by vertical bracing ribs 2%), welded to the plate 1 and to the fins 16. As shown in Fig. 4, said bracing ribs are arranged in the shape of a'hexagon having its center on axis AA, and their opposite ends extend between the points 19 above mentioned and the base plate 1. Their lower free edge is curved inwardly so as to form pointed parts at points 19, the adjoining pointed parts of fins 16 and rib 20 forming downwardly projecting prongs made of four thin converging pointed web portions.

Said fins 16 and ribs 20 are made as thin as possible, their thickness being for instance about a few millimeters.

In the example shown in Fig. 5, the above described anchor device is used to receive the recoil thrust of a mortar whose barrel 22 is supported at its front part by means of a two-legged stand 23. The rear end of the barrel is provided with a pivot 24 ending in a spherical ball member 25. The ball has a radius equal to that of the hemispherical portion and of both portions 13 of the cavity in socket 5 and it is provided with two flat parallel faces, the spacing of which is equal to the gap between the parallel faces 12 mentioned above.

It may be seen that, owing to the flared conical en trance 14 of socket 5, the barrel 22 may swing practically in all horizontal directions and vertically within wide limits around centre 0, which makes it possible to obtain large variations in azimuth and elevation when firing, wlhile retaining the barrel duly assembled'with the basep ate.

The operation is as follows:

When the anchoring device is placed on the ground, it rests on the same by the three lowermost-points 19, so that the device will assume at once a steady position even on a rough ground. The three points 19 being at equal distance from the base plate 1, it will be very easy to give said plate a horizontal position, which is .generaly preferable.

The gun being'mounted on the base plate and pointed for instance in the direction LQ (Fig. 3), when thegun is fired, the recoil force OL may be decomposed into a vertical thrust ON and a horizontal thrust OM. Inasmuch as the base plate rests originally on the ground by the three sharp points or prongs 19, formed by the thin fins 16 and bracing ribs 29, said prongs are rapidly sunk into the ground and, after a few shots at the maximum, the whole fins and ribs, together with point 15 of the socket and the peripheral flange 2 of thebase plate are sunk and the base-plate proper rests on the ground. The fact that the said members are wholly and rapidly sunk into the ground is due more particularly to the fact that the fins and ribs are thin and parallel with axis AA.

During the same short period, the lateral thrust OM is opposed with a progressively increasing efiiciency by the vertical fins and ribs digging more and more into the ground. The fins and ribs having practically a symmetrical position around any vertical plane passing through the axis AA, the radial horizontal'thrust OM is absorbed very efliciently, whatever the position of the gun in azimuth may be. When the device has been fully driven into theground, i. e. after a few shots, at the maximum, according to the hardness of the ground, the lateral stability is perfect.

It will be noted that the resistances offered to a vertical tilting movement of-the device by vertical fins l6, bracing ribs 20, flange 2 and socket 5 result in a force centered on a point (X) located substantially on axis AA, somewhere below the base plate '1. On the other hand, the recoil thrust of the gun is centered at the centerO of thesocket (or more properly speaking on thelower portion of its spherical bearing surface).

In my construction, the socket is arranged below the base plate, so that points X and O substantially comcide. In this manner the horizontal component OM of the recoil thrust and the horizontal component OS of the resistance offered by the ground are substantially opposite each other and the tilting torque 1 s practically nil. The best conditions are thus obtained to secure a perfect stability even in the first period of firing. This is not obtained in prior constructions in which the socket is located above the base plate so that an important tilting torque is developed.

On the whole, the efiiciency of my device is mainly due to the following features:

The device rests originally on the ground by three points forming a triangle and equally distant from the plane of the base plate, the anchoring members are so constructed that they will be readily sunk in the ground by the recoil thrust of the gun, said anchoring members are distributed uniformly around the vertical axis of the device and finally the socket is located below the base plate, i. e. substantially on a level with the center of resistance of the anchoring members to the recoil thrust, both socket and center of resistance being located on said axis.

Experience has shown that the stability of the anchoring device and, consequently of the gun, is absolute, irrespective of the nature of the ground and of the azimuth and elevation in firing. The anchoring takes place very rapidly after one, two or three shots without any tendency of the device either to tilt under the action of the recoil thrust or to rebound and disanchor itself under the action of the combined elasticity of the ground and of the base plate. This is true irrespectively of the character of the ground, i. e. of its consistency, its bearing strength and its heterogeneousness. In addition, to the possibility of having a shooting-field which practically includes the whole space above the ground, my anchoring device makes it possible, owing to its excellent balance, to considerably ameliorate the accuracy of fire.

In order to change the elevation, it is sufiicient to set the stand 23 at the proper angle by hand without it being necessary to displace the base-plate. The setting of the gun in firing position requires no previous earthwork since the base-plate 1 comes very rapidly into engagement with the ground. The device can be detached from the ground very easily and without strain when firing is called oif. The manufacture is simple and cheap and the device is of light weight.

Figs. 6 to 8, show a modification of the barrel locking system in which two half-shells 31 with spherical inner faces 32 rest on an annular shoulder 33 provided on the lower part 34 of the socket 35. The ball 36 carried by the extension or pivot 37 of the gun barrel 38 is retained in the socket by said half-shells 31 which leave an oblong opening 39 for the passage of pivot 37. An open resilient segment 40, which may be set in position and removed by means of two lugs 41, is mounted in an annular groove 42 of the socket and locks both half shells in position. The gun barrel 38 can thus rotate about its own axis and take any desired position both in azimuth and elevation.

Figs. 9 to 13 show various embodiments in which a plurality of anchoring devices such as above described are combined in order to afford an anchorage which is still more independent from the nature and shape of the ground, and in which the number of contact points with the ground and the dimensions of the polygon of sustentation are increased.

In Fig. 9, the barrel 42, supported in its front part by a two-legged stand 43 rests through its rear pivot 44 and ball 45, on an anchoring set comprising three anchoring devices 46, 47, 48. In each of said anchoring devices, a ball 50 at the end of a pivot 51 is locked in the socket 49 through one of the above described means, for example that of Figs. 1 to 4.

All the pivots 51 are rigidly connected by welding or otherwise to an annular beam 52, of tubular crosssection, preferably rectangular. Said beam 52 carries a central socket 53 (shown in Fig. through the medium of a number of plates 54 welded to one another at 55. Said plates 54 are arranged so as to form a kind of frusto-conical trough, so that the spherical cavity 58 in the central socket 53 will be situated on a suitable level below the base plates of the anchoring devices 46, 47, 48, i. e. on the same level as the spherical recesses 49 of said anchoring devices.

The said plates 54 are provided with lugs 56 which extend diagonally through the beam 52 and thus act to stififen the same. The plates 54 are cut away at suitable points so as not to interfere with the base- plates 46, 47, 48 in the oscillation around the three swivel joints 50. The center 0 of the central socket 53 coincides substantially with the center of the equilateral triangle formed by the centers 0 of the aforesaid recesses 49.

In operation, the recoil thrust from the gun is transmitted by the trough 54 and the annular beam 52 to each individual balls 50 and each anchoring device 46, 47, 48 works in the manner described above.

Due to the presence of the balls 50, the three anchoring devices may be situated on dilferent levels or inclined at different angles according to the character of the ground.

The annular beam 52 may have a polygonal shape as shown in Figs. 10 and 11 and springs 50* may be provided to connect the pivots 51 or beam 52 to each individual base plate 46, 47, 48.

The central ball 45 (Fig. 9) carried by the gun is retained in the cavity 58 (Fig. 10) of the central socket by two half-shells 61 (Figs. 10 to 13), forming a hemispherical cap which covers the socket. These shells are clamped on the latter by half circular flanges extending into a corresponding annular groove 73, provided in the outer side surface of said socket, so that said cap is capable of turning around the axis of the socket. Said shells provide an elongated opening 62 for the passage of pivot 44 (Figs. 9 and 11).

Both shells 61 are pivotally attached at one end to a small connecting plate 63 through two bolts 64 and nuts 65. They are united at their opposite ends by a link 66 pivotally attached on one of the shells 61 at 67. Said link may be secured to the other shell by a locking pin 68 (Fig. 12) housed in a thimble 66a made integral with said link. The locking pin is provided with an actuating knob 69 and pushed downwards by a spring 70, which normally maintains its end engaged in a hole 71 of the other shell.

Moreover, the bolts 64 and the connecting plate 63 are used to connect to each other two half-circular segments 72, pivoted to each other at their opposite end. Said half segments form a holding clip which is retained in the circular groove 73, and can slide freely therein.

Thus, the gun barrel can be rotated to the desired azimuth while its locking cap 61 remains attached to the central socket 53, even in the unlocking position of said cap.

This device has the advantage that the gun barrel can be easily locked or released inasmuch as it is sufficient to pull up the knob 69 for releasing the lockmg pin 68, whereafter it is possible to separate both shells 61 from one another by rotation in opposite directions around their respective bolts 64. All accidental unlocking of the gun barrel during fire is prevented and the whole locking device remains attached to the central socket both during firing and during transportation, even in the unlocking position. The dismountmg is, however, very easy for it is suflicient to remove the bolts 64.

On usual grounds, the definitive anchoring of the base plates 46, 47, 48 is obtained after one shot or a few shots as explained above.

Before setting the gun in firing position it may be advisable to provide, if need be, a slight excavation in the ground in order to accommodate the central socket Of course, the individual anchoring plates may be combined otherwise than shown in Figs. 9 to 13.

Thus, in the modification shown in Fig. 14, the anchorage comprises, as in the preceding example, three brace- plates 74, 75, 76 with three ball joints 77, the centres O of which are the apexes of an equilateral triangle formed by a star-shaped support or spider 78. The gun 79 is pivotally mounted, through the swivel-joint 80 in a central cavity 81 of said support, the centre 0 of which is identical with the centre of the equilateral triangle formed by the centres 0 In the preceding examples, it is possible to use nonidentical base-plates. The centres of their pivot cavities could also form a non-equilateral triangle.

In the example shown in Fig. 15, two identical baseplates 82 and 83, of hexagonal shape, are pivotally mounted at O on a rigid equalizing bar 84. The gun barrel 85 rests on said bar at its center through a ball 86, fitted in a cavity 87, the centre of which is in alignment with the centres O and at equal distance from said centres.

It would also be possible to link together two nonidentical base-plates with such an equalizing bar, the three centres O and 0 being still on a straight line and the point 0 then dividing the length O O into two segments, the lengths of which are inversely proportional to the respective active areas of the corresponding base plates.

Fig. 16 shows an anchorage comprising nine base plates and formed by the combination of three anchoring devices 85, 86, 87 respectively identical with the device shown in Fig. 14. These anchoring devices are united through a central spider 88. The barrel 89 rests on the center of said spider through a ball and socket joint. The four swivel-joints of the spider 88 are in the same plane.

Of course, the invention is not limited to the forms of execution shown and described. In the construction shown in Fig. 1, the socket and the fins 16 and ribs 20 may be made integral with the base plate 1. The arrangement of the bracing ribs 20, instead of being polygonal, may be circular or have an outline of any other form affording the desired dynamic symmetry. Each base-plate could be provided with several sets of bracing ribs concentric to one another.

Finally, the number of anchoring plates as provided in the example of Fig. 16 could be increased. For instance, it could be made three times greater by substituting for the gun barrel 89 one leg of another three arm spider 88. It could be doubled by substituting for the gun barrel 89 an equalizing bar such as shown in Fig. 15.

Having now described my invention what I claim as new and desire to secure by Letter Patent is:

1. In a gun ground-anchoring device, in combination: a plurality of spaced elemental supporting means; each said means comprising: a substantially plane rigid base plate adapted to rest on the ground and having a spherical socket centered on the perpendicular to said plate at the surface center of said plate; anchoring elements adapted to penetrate the ground, rigidly attached to and below said plate, and parallel to said perpendicular, the center of gravity of the projections of said plate and said anchoring elements onto any plane comprising said perpendicular being substantially located at a fixed point of said perpendicular, the center of said socket coinciding with said fixed point; a rigid connecting frame between said elemental supporting means, having an axis of symmetry; spherical balls dependent from said frame, substantially angularly equidistant from each other, each of said balls fitting in a said socket, forming independent articulated joints between said frame and each of said plates; on said frame, a central gun bearing cavity adapted to withstand the guns recoil, the center of said central gun bearing cavity being substantially at the resultant center of gravity of all surfaces of said plurality of elemental supporting means, the center of gravity of the surfaces of each of said elemental supporting means being considered as located at the center of the socket of the respective elemental supporting means.

2. A mortar ground-anchoring device, adapted to permit the firing of the anchored mortar on all azimuths and over a wide range of elevation angles, said device comprising in combination: a substantially plane base plate having a perpendicular axis of symmetry and an underface adapted to rest on the ground and an upper face; a single socket connected rigidly to, and centrally with respect of, said base plate, and coaxial with said axis of symmetry; said socket extending a substantial distance below said underface; in said socket, a mortaroearing central cavity coaxial with said axis of symmetry and opening onto said upper face of said base plate, and adapted to house the rear end of the mortar barrel; said central cavity comprising a substantially hemispherical bottom section having its center on said axis of symmetry below said base plate, and an upper flared section of revolution coaxial with said axis of symmetry and the diameter of which increases from said bottom section to said upper face; a plurality of tapered anchoring elements rigidly attached to said base plate and projecting below the underface of said base plate, in a direction parallel to said axis of symmetry; said anchoring elements being distributed around said axis of symmetry; said socket and said anchoring elements being designed and constructed to penetrate into the ground under the action of the recoil of the mortar; the shape of said base plate and the shape and distribution of said anchoring elements being such that the center of gravity of their projection onto a diametral plane comprising said axis of symmetry is located substantially on said axis of symmetry; said center of gravity, through which passes the resultant of the ground reactions when said anchoring elements are fully sunk in the ground, merging with the center of said bottom section, the reaction of said mortar passing through said latter center; retaining means for the rear end of said mortar, removably mounted in said central cavity and rotatable around said axis of symmetry and disposed between said bottom section and said upper section of revolution; said retaining means being constructed and adapted to allow the free pointing of the mortar in all directions around said center of said bottom section; said bottom section further comprising at its upper end a shoulder and a cylindrical surface above said shoulder; a circular groove in the inner wall of said cylindrical surface, at a distance above said shoulder; a resilient segment partly located in said groove and partly projecting inward from said groove; and a slot formed by and between said shoulder, said cylindrical surface and said resilient segment; said retaining means being rotatably mounted in said slot.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,730,800 Brandt Oct. 8, 1929 1,850,034 Samaia Mar. 15, 1932 2,046,518 Joyce July 7, 1936 2,182,010 Brandt Dec. 5, 1939 2,557,960 Gerhardt June 26, 1951 2,558,024 Weiss et al June 26, 1951 FOREIGN PATENTS Number Country Date 570,613 France Jan. 18, 1924 462,509 Great Britain Mar. 10, 1937 816,093 France Apr. 26, 1937 494,355 Great Britain Oct. 25, 1938 876,128 France July 20, 1942

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