US2378691A - Portable ground mortar - Google Patents

Description

H. J. FANGER ETAL PORTABLE GROUND MORTAR June 19, 1945.

Filed April 15, 1942 IN VEN TORS HERMAN J1 FANGEE g -lszve Y 62 uezwm GEN .4 7- ran NEX Patented June 19,1945

PORTABLE GROUND MORTAR Herman J. Fanger and Henry Gruenhagen, Oakland, Calif., assignors of thirty per cent to Martin C. Mogensen, Martinez, Calif., thirty per 1 cent to Herbert W. Erskine, Piedmont, Califi, thirty per cent to Cleve F. Shaffer, San Francisco, Calif., five per cent to. said Henry Gruenhagen, and five per cent to said Herman J;

Fanger Application April 13, 1942, Serial No. 438,682 6 Claims. (01. 89-37) The present invention relates to portable emplacement mortars for military purposes and more particularly relates to mortars adapted for portability which may be quickly and efficiently set up upon ground emplacement and readily projectiles.

The objects of the invention are to provide a folda'ble mortar which has a base support or ground plate of substantial size for mounting the mortar thereon. To provide a thrust block upon a ground plate to receive recoil of thrust due to firing the mortar; to provide a mounting means in connection with a thrust block whereby a mortar barrel may be pivotally swung from air-inoperative portable position to an operative position and releasably locked thereat. A further object is to provide 'a mortar-mounting means adjacent one end of'a ground plate of substantial length for providing an area of plate upon which pressure may be exerted by the foot of the operator; to provide a mortar having its rear end pivotally mounted in a support member, the position 'of which may be changed by reciprocation to :provide foldability of the mortar barrel relative to the ground support. A further object'is 'to provide a mortar readily transportable, very light in'weight, rapidly adaptable changed in their angle of elevation for firing to ground placement and rapid firing, having simple adjustment of angle of barrel-inclination, having sturdy construction with ,minimum of parts, and ease of rapid assembly and disassembly for cleaning and repair and replacement of parts.

"With the foregoing and other objects in view, all of which will be more apparent .as this 'description proceeds, the invention consists of the parts and combination of parts herein described and illustrated in the 'accompanying drawing to which referenceis made, it being understood that Fig. 3 is a longitudinal. horizontally transverse section on line III-IIIof Fig. l, the view being enlarged. v

Fig. t is a longitudinal fragmentary side elevation of portions of structure in Fig.3.

Fig. 5 is a perspective of a portion of ground plate.

Fig. 6 is a perspective of a yoke arm structure.

Fig. 7 is a perspective of breecheend of a mortar barrel.

Referring to the drawing in which like characters of reference indicate corresponding parts in the several views, 10 is a ground plate-of suitable length and width to provide substantial base or foundation for the mortar in operation on the ground, and yet not of such extremes of dimension as to prevent thelground plate frombeing carried on the back or shoulder of a soldier when the mortar is being transported, suitable shoulder straps for such purpose being connected at each end of the ground plate. as indicated at H. Asuitable size for the ground plate may be suggested as approximately eight inches wide and twenty inches long. It is preferred that the ground plate have-depending flanges I2 on its longitudinal edges for reforcement purposes and also to gripthe ground surface to prevent lateral movement. At its underside the ground I plate may also be provided withtransverse cleats [3 which serve to grip the ground and stabilize the'mortar in its position against the thrust of recoil when themortar is fired. The opposite or upper face of the ground plate has a transverse buttress. or recoil block- M which may be of angle-iron construction having one of its legs or flanges. Ma resting parallelly 0n the upper.

face of the ground plate and welded thereto as at P5 and having its other leg or flange .l lb upstanding. The buttress block I4 is positioned adjacent one end of the ground plate l0, so as to'provide a fiat rearward area of ground plate upon which the foot of the operator maybe placed to stabilizethe mortar against kicking out of position from the recoil oi firing. The

upstanding guide member H, the latter bein herein exemplified as substantially a quadrant of ancircle, the an'gleof the quadrant being replate with its lower end more nearly adjacent the angle of the quadrant. Manifestly the ground plate, buttress blocks and guide member could be made integrally, but for simplicity of structure it is believed equally efficient, and certainly more economical in making repairs and replacements of parts, to have various elements thereof connected by welding. 4 p

There is further provided for mounting on the ground plate a simplified and efiicient mortar which consists of a minimum number of parts ruggedly constructed which may be assembled or disassembled easily and with great rapidity for cleaning, replacements and repair. A mortar barrel is provided having the usual discharge; end 2| and a breech end 22. The breech end comprises a sleeve 23 of relatively heavier material than the forward portion of the barrel, since the breech end must withstand the maximum of explosive force. The forward end of the sleeve 23 is internally threaded as at 24 to receive the threaded end of the barrel 20 to make a tight joint. Adjacent the connection of barrel 20 and sleeve 23, the barrel may have its wall thickness increased to provide thickness of material in which external axially longitudinal grooves 26 may be circumferentially spaced, whereby the barrel and sleeve may be more readily connected and disconnected to the breech sleeve. The breech end of the sleeve 23, is closed by a breech block 2! which has a relatively small opening 28 therethrough for receiving a firing pin 29. At its rearward end the breech block 23 is provided with a shoulder tenon 30, the latter having an extended cylindrical member 3| which is axially'recessed as at 32 and adapted for slidably receiving a cylindrical body 33 of the firing pin 2-9, the firing pin body 33 being also axially recessed for receiving a compression spring 34 which furnishes the force for driving the firing pin 29 in its usual function of exploding a charge in the breech end of the barrel. The barrelled portion of the mortar heretofore described is mounted upon the upstandin quadrantal guide member I of the ground plate by means of a bifurcated yoke consisting of two relatively spaced opposing arms 35, 36 which have one end releasably connected to the tenon shoulder 30 of the barrel by bolts 31 extending through suitable holes in said yoke armsand into openings 38 in the tenon shoulder. The yoke arms are reinforced at their peripheral edges by a flange or angle iron construction 39, the intermediate web portion 40 having spaced elongated slots 4| to permit a reasonable degreeof resilience in the web portion of the arm. The forward portion of one arm, preferably the right hand arm when the apparatus is in use, is provided with a trigger slot 42 which may be'open at its forward end 42a, and provided with a bayonet lock 43 at its rearward end, for slidably receiving therein a manually operable trigger member 44. The shank of trigger 44 extends through the slot 42 of the yoke arm and is also slidable in slot 45 in the cylindrical extensionmember 3i withinw hich the firing pin cylinder 33 reciprocates; One end of the trigger shank fixedly engages the firing pin cylinder 33' as indicated at 46. Each yoke arm 35, 36 at its end removed from a pivot pin or bolt 48, the are being substantially similar in curve to the arc of th thrust blocks IB upon which the arcuate ends 'of the yoke arms slidingly abut. The yoke arms 35, 36 are relatively connected for pivoting in the slot I! by the headed bolt member 48 which extends through holes in the spaced arms and through slot l9, be-

ing secured by nut 49. Upon the bolt 48 there is mounted a spacer bushing 50 by which the yoke arms are maintained relatively spaced at their arcuate end substantially the same width as at their forward end where they are spaced by the tenon 30, the bushing 50 being substantially of a diameter to slide reciprocably and snugly in the slot 19. 'Thelateral transverse width of arc portion Ila of the. quadrant is a trifle less than the length of bushing 50 and the tenon 30, so as to provide a bare'sliding clearance between the opthe barrel is formed in an arc d'l'concentrictwithi.

posed faces of the yok arms and the side faces Ila of the quadrant, so as to permit clamping of the arms against the side faces of the quad-- rant. v

A clamping means is: provided for clamping the yoke arms against the side walls of the quadrant for maintaining the mortar barrel at any predetermined selective angle of inclination relative to the ground plate for purposes of firing projectiles, and for clamping the barrel at reverse or folded position as shown in Fig. 2. Either the arcuate face or the side wall of the quadrant arc may be calibrated in degrees as at 5! to visibly indicate angle of elevation. However, it is realized that this calibration would riot always be accurate since uneven ground might tilt the ground plate from an exact geometrical plane; It is therefore preferable that some suitable type of accurate level and protracting device be employed, and a device of such characteris indicated in the drawings by the reference numeral 52. The clamping means referred to above comprises a shaft 53 which extends through the web portion 40 of the opposed arms 35, 33, having at one of its ends a lever member 54, and having threads at its opposite end for receiving a nut 55 which is locked against rotation by dowel pins 56 received in holes 51 in the body of the web 40. If desired more than two dowel pin holes 51 may be provided in the web to relatively adjust the threading of the nut and quadrant when the clamping means is released;

Thus, the elevationof the mortar may be adjusted with greatease and rapidity, and at the same time also insure its stability'a't the selected elevation. The shaft 53 may also serve as a stop member against which the firing pin spring 34 may abut. l

It is apparent that the firing pin may be retracted against the tension of spring34 and locked in the bayonet slot 43, andreadilylreleasedto fire a shell by the manual release of the trigger from the bayonet lock. l I

When it is desired that the mortar be transported either on the back-of a soldier by means of may, .upon '=-loosening of the clamping means 5,3,58,' be conveniently-folded, to a reversed-position .to' lie substantially parallel with and overlying the ground, plate, as best shown in Fig. 2 in which event the pivoting members 48, 50, may slide forward and upward in the slot I9 and thus elevate the pivoted end of the yoke. arms whereby the barrel may be folded to the position-shown in Fig. 2- (and in dotted lines in Fig. 1). In accomplishing this reversal and folding, the yoke arms 39 and barrel 20 are first moved on pivot 48 to a position vertically perpendicular to the ground plate :llland. as they are moved beyond the perpendicular, the yoke arms fulcrum on the top edge of the upstanding leg Mb of angle-iron l4, and this leverage forces the pivot 48 along and upwardly in slot IS, the length of the slot being such that when the mortar barrel is completely reversed and folded somewhat parallelly to ground plate In, as shown in Fig. 2, the pivot 48 has reached the end of the slot l9 and thus the folded length of the device is shortened to the extent of the length of slot I 9. After the reversal and folding of the mortar the clamping means 53-58 may again be tightened against the rim of guide member IT to firmly hold the mortar in its folded position. As thus folded the clamping means may again be tightened to secure the mortar in its folded position.

It will be noted that in Fig. 3, there is shown a device in the mortar barrel, which bears the reference characters A, B, and C. This device is an adapter member A having a sealing-valve plate B mounting an explosive bomb C, which are not a part of this invention, but are included in other applications. They are conventionally shown here to illustrate the idea that the sleeve member 23 of the mortar is preferably of sufficient axial length so as to include the adapter A and sealing plate B since the greatestpressure of the explosive force is rearwardly of the sealing plate B to overcome the inertia of the projectile body.

Having thus described the invention, what is claimed to be new and patentable is:

1. A portable mortar, comprising a ground plate having a mortar support on one face thereof including a thrust blockhaving an arcuate face to receive the thrust of explosive recoil force, an upstanding guide member having an arcuate outer rim and having within said rim a slot inclined outwardly and upwardly from the central portion toward said rim, a mortar barrel closed at one end by a breech lock and having connected thereto rearwardly extended yoke arms straddling said arcuate rim and having their opposite free ends arcuate and adapted for slidably seating against the arcuate face of said thrust block, said yoke having a pivot member adapted to slide in said slot, the rear portion of the thrust block being upstanding and providing a fulcrum for said yoke arms when the mortar is swung reversely rearwardly on said pivot of the yoke arms in the slot of the upstanding guide member, whereby the pivot member of the yoke arms is moved along and upwardly in said inclined slot.

2. In a portable emplacement mortar, a ground plate having a mortar support on one face thereof, said mortar support including a thrust block providedwith an arcuate faced portion to reof.v the barrel provided withv an arcuate free end adapted for seating; against .the'arcuate. faced portion ofthe thrust" block, said. arms including swungreversely rearwardly on saidpivot, where:

by the. pivotmember of the yoke armsis moved alongand upwardly in said, inclined slot.

,3;'In a, portable emplacement mortar,.a mortar support including a ground plate providedzwitha thrust block provided with an arcuate surface to receive the thrust of explosive recoil force and an upstanding arcuate rimmed guide member having a slot extending radially outwardly and upwardly from the central portion, a mortar barrel closed at one end by a breech block, a bifurcated yoke extending rearwardly from the breech block and having its free end formed arcuately for abutting on the arcuate surface of the thrust block, said free end portion of the yoke having a pivot member in said slot and on which 'the yoke arms and mortar may be swung arcuately, a fulcrum member rearwardly of the arcuate portion of the thrust block, said yoke arms being adapted for engaging said fulcrum when the yoke and mortar are swung arcuately reversely on said pivot and whereby said pivot is movedupwardly and along said slot, and means for clamping said yoke in releasably fixed relation to the sides of said guide member.

4. A portable mortar, comprising a ground plate having a mortar support adjacent an end of one face thereof including an upstanding laterally transverse thrust block provided with an arcuate face portion to receive the thrust of explosive recoil force, and an upstanding guide member longitudinally of the ground plate and having its rear wall abutting the thrust block, the forward wall of the guide member being arcuately rimmed, said guide member having a slot therein extending radially upwardly and outwardly relative to the radial center of the arcuate rim of the guide, a mortar barrel closed-at one end by a breech block, a yoke member extending rearwardly from the breech block straddling said arcuate rim and having an arcuate free end adapted for abutting on the thrust block, said yoke including a clamping means releasably extending through the yoke whereby said yoke may be releasably held in selective position relative to thearcuate rim of the mortar support, a pivot means extending through said yoke arms and slidably engaged in the slot of the guide mem: ber, the arms of said yoke having slots therein adjacent the clamping means whereby said arms have a degree of resilience adjacent said clamping means to facilitate the clamping thereof.

5. In a portable emplacement mortar, a mortar support including a ground plate, an upstanding thrust block laterally transverse of the ground plate and including an arcuately faced portion to receive thrust of explosive recoil force, an upstanding quadrantal guide member longitudinally of the ground plate and having a slot therein radially to the angle of the quadrant, a mortar barrel closed at one end by a breech block having a manually operable firing pin, arms extended from the breech end of the barrel and straddling the guide member, said arms having arcuate free ends for abutting the arcuate face portion of the thrust block, the said arms having a connecting pivot member which is slidably engaged in said s1ot, and means'for releasabiy locking said arms against the sides of the guide member.

6. In a portable mortana support for a mortar barrel, including a ground plate having a mortar support adjacent one end .of one face thereof, the mortar support including an upstanding thrust block laterally transverse of the ground plateand having an arcuate face portion to receive thereagainst the thrust of explosive recoil force from the firing of the mortar, an upstanding arcuately 10 rimmed guide member longitudinally of the ground plate and provided centrally with anelongated slotangularly disposed in a vertical plane radially upwardly and outwardly relative to the angle of the base and rear wall of the guide memher for slidingly' receiving a pivot means at the breech end of a mortar barrel whereby the barrel may be selectively swung arcuately'relative to the mortar support and when swung beyond a vertical position perpendicular to the ground plate may engage the upper edge of the upstanding thrust block and fulcrum thereon for moving the pivot upwardly and outwardly in said slot.

HERMAN J. FANGER.

HENRY GRUENHAGEN.

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