US2858740A

US2858740A - Gun carriage rotatable through 360 deg.

Info

Publication number: US2858740A
Application number: US302282A
Authority: US
Inventors: Michael G Harring; Nathan S Glassman
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-08-01
Filing date: 1952-08-01
Publication date: 1958-11-04
Anticipated expiration: 1975-11-04

Description

Nov. 4, 1958 V M. 'CJHARRING ETAL I 2,8585740 GUN CARRIAGE ROTATABLE THROUGH 560 Filed Aug. 1, 1952 (sheets-sheet 1' gwue/wkvw Michael E. Hurring. n Nuihun .5. 51115511111111 Nov. 4, 1958 M; c. HARRING ET AL GUN CARRIAGE ROTATABLE THROUGH 360 4 Sheets-Sheet 2 Filed Aug. 1', 1952 Wa Wmm MT Qua ma .m MN

Nov. 4, 1958 M. c. HARRING- EIAL 2,853,740

GUN CARRIAGE ROTATABLE THROUGH 360 Filed Aug. 1, 1952 4 Sheets-Sheet 3 giwww Mi chual Ei. Hurrins Ntfihnn \5. Elnasmun Nov. 4, 1958 M. c. HARRING ETAL 2, 5

' GUN CARRIAGE ROTATABLE THROUGH 560 Filed Aug. 1, 1952 4 Sheets-Sheet 4 IN VENTOES -Hurnins Blue, .smun

Mi 1:111: 21 E Nnthnn 5 2,858,740 GUN CARRIAGE ROTATABLETHROUGH 360 Michael G. Harring, Silver Hill, Md., and Nathan S. Glassman,'Falls Church, Va.

Application August 1, 1952, Serial N0. 302,282 20 Claims. c1. 89-40) (Granted under Tifle as, of. some 1952 see. 266

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to us of any royalty thereon.

. The present invention relates to a new and improved artillery carriage. More particularly, the present inventionrelates to a new andimproved, light-weight carriage for mobile artillery wherein the firing forces are absorbed by the firing platform carried by the lower carriage and wherein the wheels together with the gun and the carriage are raised above ground as the platform is lowered into emplacement. 1

It is also worth noting that the use of the firing platforms in accordance with the present invention, as illustrated in Figures 13, 7 and 8, permits ready adjustments for cant correction of the gun in case ofits emplacement into non-level or mountainous terrain.

It is accordingly an objectof the present invention to provide an improved, light weight guncarriage.

It is another object of the present invention to provide a novel gun carriage which permits 360 firing traverse.

It is a further object of the present invention to provide a gun carriage for mobile artillery which may be readily put into emplacement for firing by lowering the firing platform and which may also be readily placed into marching condition by raising the platform.

It is still another object of the present invention to provide a new and improved gun carriage which is so designed as to absorb all firing forces directly through-a strut on which the lower carriage rests and which is connected to the firing platform, and wherein substantially no forces are transmitted to the trails.

A still further object of thepresent invention is to provide a firing platform which comprises spades forming an integral part with the firing platform.

Another object of the present'invention resides in the direct connection between the lower carriage, the firing platform and the trails.

These and other objects and advantages of the present invention will become obvious from the following description when taken in connection with' the accompanying drawings which show for purposes of illustration only several of the preferred embodiments of my invention and wherein:

Figure 1 is a plan view of the carriage in accordance with the present invention with the barrel removed from the trunnions thereof; 6

Figure 2 is a cross-sectional view of the gun carriage in accordance with the present invention taken along lines 22 of Figure 1;

Figure 3 is a cross-sectional view of the gun carriage in accordance withthe present invention taken along lines 33 of Figure 1;

Figure 4 is an enlarged cross-sectional view of the upper carriage, the lower carriage and the connecting bearing therebetween of Figure 2.

Figure 5 is an enlarged front view of the hand wheel and associated mechanism used for lowering and raising the firing platform in accordance with the present invention;

Figure 6 is an enlarged, plan view of the hand Wheel of Figure 5 with part of the hub broken away to show the ratchet mechanism;

Figure 7 is a plan view of the firing platform used in Figure 1; I

Figure 8 is a cross sectional view-of a modified form of the firing platform in accordance with the present invention.

Referring now more particularly to the drawings where like reference numerals are used in the various views thereof to designate like. parts, reference numeral 1 designates the lower carriage which is circular in shape and is made of a rectangular, box-type frame 2. Attached to the peripheral surface of frame 2 are two supporting

brackets

3 and 3 which may be welded as at 4 or fastened to frame 2 in any conventional manner. The lower portions 5 and 5' of brackets 3 and 3' extend outwardly and inwardly under frame 2 and are each provided with a bore 6 and 6' to receive shafts 7 and 7.

Wheels

8 and 8 are rotatably supported on shafts 7 and 7' as by means of a spindle and suitable bearings (not shown) as is well known in the prior art. Reinforcing webs 9 and 9" are provided between supporting brackets 3 and 3' and theirlower shaft housing portions 5 and 5'. Trail sup- 14' respectively.

Extension

13 and 14, and 13 and 14' are spaced apart a distance slightly greater than the vertical dimension of brackets 10 and 10' so that

extensions

13 and 14, and 13 and 14' will slide over brackets 10 and 10' to form a tongue and groove arrangement therewith.

Extensions

13, 13', 14 and 14 each are provided respectively with a vertical bore 15, 15, similar to vertical bores 11 and 11 and aligned therewith so as to constitute a pivotal joint for trails 12 and 12' after insertion of pins 16 and 16' through aligned bores 15, 11 and 15, and bores 15', 11' and 15'.

A segment of a gear ring 17 is secured to the upper surface of frame 2 by means of bolts 18 and nuts 19. Gear ring 17 serves to provide limited rotation of the upper carriage 20 in azimuth as will be more fully described hereinafter. Upper carriage 20 is rotatably mounted on lower carriage 1 by means of bearing 21, which may be of the divided race, radial thrust type (Fig. 4). Upper carriage 20 comprises a ring-22 to which are fastened in any conventional manner two parallel, upright brackets 23 and 23'. The forward ends of brackets 23 and 23' are joined together by a curved member 24 so as to form a horseshoe-like configuration as viewed from above in Figure 1. Brackets 23 and 23' and connecting member 24 have an inverted L-shape in, cross-section, with a relatively thin, vertical member 25 extending upwardly from ring 22 and an outwardly-; extending flange or leg portion 26 at right angle thereto. Brackets 23 and 23' slope upwardly in the rearward direction to house trunnions 27 and 27 and include verti- Upper carriage and therewith gun barrel 39 is traversed in azimuth to a limited extent to provide fine adjustment for arming by means of azimuth handwheel 40,

shaft 41, universal joint 42, shaft 43, worm 44 aflixed to shaft 43, worm gear 45 mounted on shaft 46, and pinion 47 aflixedto shaft 46 which meshes with gear ring 17 (Fig. 1).

The firing platform 48 comprises downwardly extending

spades

49 and 49 at right angles to each other. A circularly-shaped recess 50 forming a socket is provided in thecenterof firing platform 48 for ball 51 on the end of short connecting member 52; ball 51 is secured to firing platform 48 by means of retainer ring 53 which maybe threaded into firing platform 48 or fastened thereto by bolts. Member 52 is fastened to stud 54' in any conventional manner as by welding or the like and includes a transverse bore 55 to receive bushing 56. Shaft 57 fits slidably within bushing 56 and comprises flattened-out endv portions 58and 58 each of which. is provided with transverse bore 59 and 59 respectively. Flattened-out end portions 58 and 58' constitute the tongue of the tongue-and-groove connection between shaft 57 and connecting links 60 and 60 which interconnect stud 52 with trails 12 and 12 as will appear more fully hereinafter.

Connecting links 60' and 60' are each provided at their forward end with a two-pronged, fork portion 61 and 61' having transverse bores 62 and 62 which are aligned with bores 59 and 59 (Fig. 2) in such a way as to form a tongueand-gro ove joint when assembledtherewith as by means of bolts and nuts, or pins and cotterpins (not shown). The rearward ends of connecting links 60 and 60' are also provided with a two-prOnged, fork portion 6'3- and 63' having: transverse bores 64 and 64 (Fig. 2).

Lugs

65 and 65 are fastened to trails 12 and 12' and project downwardly therefrom. Each

lug

65 and 65 is provided with a bore 66 and 66' respectively which receive shafts 67 and 67' rotatably supported therein. Shafts 67 and 67' each comprise flattened-out end-portions 68 68' having

transversal bores

69 and 69;

end portions

68 and 68 constitute the tongues of the tongueand-groove joint when assembled with fork portions 63 and 63'. The last-mentioned tongue-and-groove' joints together with rotatable shafts. 67 and 67' form universal joints, and may be replaced by any other universal joint, such as a ball joint, if so desired. It is thus seen that flexible universal connections are provided between the trails and the firing platform. These connections, together with the universal connectionprovided by ball 50 and socket 51, and ahere-inafter described pivotal connection between strut 54 and the crank mechanism for raising and lowering the firingtplatform, enable the entire carriage. to be slewed around through 360, or tilted to correct for cant as is readily apparent from inspection of the illustrated drawings.

Thegun raising and lowering mechanism for the firing platform 48 comprises hand wheel 70 which drives shaft 71 as will be explained more fully hereinafter. Shaft 71 is rotatably supported within shaft housing 72 which is fastened to the outside of frame 2 of lower carriage 1 thereby also supporting handwheel. 70. Rotation of shaft 71 is. transmitted to shaft 73- through universal joint 74. A bevel. gear 75 is afiixed to the end of shaft 73. Bevel gear 75 meshes another bevel gear 76: aflixed to'vertical shaft. 77 which carries worm 78 (Figs; 2 and 3). 78. drives worm gear 79- which is fastened to shaft 80. Afiixed to shaft 80 aretwo pinions 81 and 81 which mesh with segmental gear racks: 82 and 82' which are fastened to flanges 83 and 83- of shaft 84' as by means of screws 85'. Cranks 86 and 86' extend downwardly from flanges 83 and 83 through the cut-out portions of segmental racks 82 and 82 asbest shown in Figures. 2' and 3; Cranks86 and 86' are provided with. aligned transverse bores 87.and. 87. respectively. Upper portion 88' of stud 54 also includes a transverse bore 89 and is of Worm.

4 lesser thickness than the spacing between cranks 86 and 86' so that upon assembly with pin 90, cranks 86, and 86 and upper portion 88 form a tongue-and-groove joint.

When the gun is in firing position the top 91 of upper portion of strut or stud 54,; which is substantially flat, rests against the lower surface of block 92, which has a predetermined incline and which is afi'lxed to the underside of lower carriage 1, as seen in Figure 3.

Shafts 80 and 84 of the raising and lowering mechanism for the firing platform are journaled between two

vertical side plates

93 and 93 which are best shown in Figure 2. outwardly-facing horizontal top and bottom plates 94 and 94 are affixed at right angle to

vertical side plates

93 and 93 and form therewith channel-type beams, which run parallel to upright brackets 23 and 23 and are fastened to the inner surface of frame 2 at their forward and rearward ends as by means-of bolts 95 and nuts 96 best shown in Figure 4'. Inorder to protect bevel gears 75 and 76, shaft 77, worm 78 and worm gear 79 side cover plate 97, and front cover plate 98 are provided. The contour of the upper horizontal plates are best shown in Figure 3 by the: solid and parallel dotted lines representing the same. It is understood that all rotating parts of the raising and lowering mechanism for the firing platform as well as the rotating parts of the elevation. and traversing. mechanism may be journaled in appropriate bearings.

Referring to Figure 4 which shows the details of the divided race, radial thrust bearing 21, which permits free rotation between the upper carriage 20 and the lower carriage 1, reference numerals 99, and 22 designate the rings which form therace for the balls 102. Rings 99 and 100 each have bevelled

edges

103 and 104 respectively whereas ring'22 comprises a V-shaped groove 105. As shown in Figure 4, bevelled

edges

103 and 104 and groove105 areof such dimension and so arranged as to form a race substantially square in cross-section which will receive balls1102.

In the assembly of the bearing, seal retainer 106 including seal 107 are first placed into position on flange 108 which forms an. integral part with frame 2. Next ring 100 is superimposed on retainer 106 which will be retained in: its predetermined position by the weight thereof. Ring 22- isv emplaced next, following. whichballs 102 are poured into the race' which is thereupon closed by placing ring 99- on ring 100 as shown in the drawing. Seal 109 is kept in place by seal, retainer 110 which is fastened to the-top of frame 2 by means of bolts 111 and nuts 112. Ring 22 is fastened to the base plate 113 of upper carriagev by means of threaded bolts 114. Webs 115 and 115- are provided between base plate 113 and upright brackets 23- and 23' of upper carriage 20 for purposes of reinforcing the structure of upper carriage 20'.

In view of the fact that the raising and lowering. of firingv platform 48- places the weight of the gun on stud 54 and temporarily on cranks 86 and 86, a ratchet mechanism is provided: with handwheel 70' as shown in Figures 5 and 6 to facilitate rotation thereof by means of handle 116 which extends radially from handwheel 70 and which consequently may be made of greater length thereby increasingv the available torque over that obtained with the conventional handle 117 mounted in the rim of handwheel 70 at right angle thereto. The ratchetmechanism comprises two ratchet wheels 118- and 119 fastened to shaft 71 in any conventional. manner, which have their respective ratchet teeth in opposite direction as shown in Figure 5. Two ratchet'pawls 120: and 121 are pivotally supported on shafts 122- and 123 respectively which are mounted between hub 124 of handwheel 70 and cover plate 125 fastened to flange 126' ofhub; 124' by means of screws 127. Ratchet pawls 120 and 121 which face" in opposite directions, are normally forced into engagement with ratchet Wheels" 118 and 119' byclick springs 129 and 130.

In order to provide for alternate operation of the conventional manner.

fatchet mechanism in one or the other direction so as to raise :or lower the firing platform48, a small detent 131 is provided which is afiixed to knurled knob 132 in any In order to permit limited rotation of detent 131 within flange 126, cover plate 125 includes a segmental, cut-out portion (not shown) which is sufliciently large to allow predetermined circular motion of the connection between detent 131 and knob 132. Knob 132 is rotatably mounted in cover plate 125. Detent 131 alternately disengages ratchet pawls 120 and 121 from ratchet wheel 118 and 119 depending only on its manually adjusted position.

Firing platform 48 includes four symmetrically spaced bores 133 and reinforcing plate 134 (Fig. 7) to adequately secure the firing platform 48 to the ground even in hard or rocky terrain by driving appropriate stakes (not shown) into the ground through bores 133. Lug 135 is provided on top of firing platform to secure it in its raised position to lower carriage 1.

The firing platform 136, which is illustrated in Figure 8, is a modified form of firing platform 48; similar reference numerals are used in this figure toindicate parts similar to those used with firing platform 48. Firing platform 136 comprises four spades 49 and 49' at right angles .to each other extending downwardly from horizontal plate 137. Fastened in any conventional manner to the top of plate 137 is base 138 which has a spherical recess 139 in its upper surface constituting the bearing surface for bearing member 140 which is shaped spherically at its lower bearing surface 141 complementary to spherical recess 139. A retainer plate 142 is fastened to base 138 by means of bolts 143 and comprises a circumferential, spheroidal segment 144 having its center coincidental with the center of

spherical surfaces

139 and 141 so as to confine member 140 to rotative movement and prevent all except limited radial displacement therefrom as for example when correcting for cant. Such radial displacement is provided by limiting the diametral dimensions to an extent to provide annular clearances or spaces between the peripheral edges of bearing member 140 and the upstanding walls formed by the opposing faces of retainer plate 142 and spheroidal segment 144, as plainly seen in Figure 8. A dust cover 145 is fastened to retainer plate 142 by means of bolts 146.

In the embodiment of Figure 8 the short connecting member 52 is provided at its lower end with a rectangular boss 147 which is secured to bearing member 140 in nonrotative relation by retainer cap 148 which is of substantially similar rectangular configuration as boss 147 so as to fit over boss 147. Retainer cap 148 comprises a circumferentially extending, horizontal flange 149 having vertical bores 150 to receive bolts 151 which are used to fasten retainer cap 148 to bearing member 140. It is thus seen that the particular form and features of the parts in firing platform 136 effectively provide a universal joint between the gun properly speaking including the lower carriage 1, the upper carriage 20, etc., and the firing platform properly speaking including spades 49 and 49', horizontal plate 137 and base 138. While the firing platform illustrated in Figure 8 may be somewhat heavier than the one shown in Figures 2 and 3, it offers the advantage of greater ease of correction for cant and exhibits increased stability especially in mountainous terrain since it provides a greater surface of contact between those parts forming the universal joint between the firing platform and the lower carriage.

In the operation of emplacing the gun for firing, at first the split trails 12 and 12 are spread apart. Due to the linkage existing between trails 12 and 12 and stud 54 through connecting links 60 and 60, the

firing platform

48 or 136 will move slightly backwards in such a way as to describe an are around the center of pin 90, which is stationary for the time being, as necessitated by the position of the trails 12 and 12'. Next handwheel 70 .iSrotated by means of conventional handle 117, to lower the

firing platform

48 or 136 from its marching position indicated in Figure 3 in dotted lines until the spades 49' and 49' touch the ground. In order to force cranks 86 and 86' further downward additional torque is required to rotate handwheel 70 since further downward movement of cranks 86 and 86 effectively raises the gun-and, therefore, requires lifting of the entire weight ordinarily carried by wheels 8 and 8' and about to be transplanted to and carried by the firing platform and stud 54 after the wheels 8 and 8' are raised above ground.

This is accomplished by inserting handle 116 which extends radially from handwheel 70 and adjusting the ratchet mechanism by turning knurled knob 132 in the proper direction to assure that the correct ratchet pawl engages its corresponding ratchet wheel to assure proper lowering operation of the firing platform.

Rotation of handwheel 70 is continued with the aid of handle 116 until the gun is inv firing position with upper portion 88 of stud 54 resting against the underside of block 92 which necessitates turning cranks 86 and 86' beyond their vertical position as shown in Figure 3. If necessary stakes may be driven through bores 133 in order to further anchor the platform. All forces resulting from firing of the gun are absorbed by the firing platform in firing position, since such forces are transmitted from the barrel through the trunnions 27 and 27' to upper carriage 20, from upper carriage 20 through bearing 21 to lower carriage 1, from lower carriage 1 through block 92 to stud 54, and to firing

platform

48 or 136. Substantially no forces are transmitted to and absorbed by trails 12 and 12' while substantially all recoil and counterrecoil forces are absorbed only by the firing platform.

In order to raise the

firing platform

48 and 136 it is only necessary to effectuate in reverse order the steps taken for lowering the same by rotating handwheel 70 in the opposite direction.

While we have shown and described only two preferred embodiments of our invention it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes or modifications without departing from the spirit thereof, and we desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

We claim:

1. A two wheeled gun carriage comprising a first support member forming a lower carriage, an upper carriage supported for limited horizontal rotation on said lower carriage, a firing'platform carried by said lower carriage and including spade means afiixed to the underside thereof for supporting said carriage on the ground when said carriage is in firing position, a raising and lowering mechanism for said firing platform and means including a universal joint connecting said firing platform to said raising and lowering mechanism, said universal joint providing a cant correction for said gun carriage and permitting 360 rotation of said gun carriage about a vertical axis.

2. The combination in claim 1 including a gun barrel fixed to a horizontal shaft trunnioned on said upper carriage, means including a gear train on said upper carriage for aiming said gun in elevation, and means including a gear train on said upper carriage and a segmental gear ring on. said lower carriage for limiting rotation of said upper carriage.

3. The combination in claim 1 wherein said universal joint comprises a ball secured to said strut and received in a socket formed in the upper surface of said firing platform.

4. The combination in 1 wherein said universal joint includes a first spherically shaped plate having an upstanding peripheral wall secured to the upper surface of said firing platform, a second complementary sphericallyshaped plate secured to said strut and intimately engaglower carriage cooperating with said upper carriage tolimit rotation of said upper carriage in azimuth to a predetermined small angle, a gun barrel pivotally supported by said upper carriage, a firing platform carried by said lower carriage and comprising spade means at the underside thereof to contact the ground when said artillery piece is in firing position, means including crank mechanism on said upper carriage for raising and lowering said firing platform, and means including a universal joint connecting said firing platform to said raising and lowering mechanism, said universal joint providing a cant connection for said artillery piece and permitting 360 horizontal rotation of said artillery piece.

6. The combination in claim 5 including an emplacement member comprising a pair of divisible trails pivotally connected to said lower carriage, a pair of support rods, and linkage means including universal connections for connecting one end of each rod to said universal joint and the other end to a corresponding trail whereby substantially all forces of recoil and counterrecoil are absorbed by said firing platform.

7. In combination with an artillery piece, a two-wheel gun carriage comprising an annular support member forming a lower carriage, an upper carriage supported for limited horizontal rotation on said lower carriage, an emplacement member comprising a pair of divisible trails pivotally connected to said lower carriage, a firing platform, a strut, a universal joint connecting one end of said strut to said firing platform, crank mechanism rotatable on a horizontal shaft mounted on said ripper carriage, means pivotally connecting said crank to the other end of said strut and actuable to move said firing platform from stowed to firing position, a pair of support rods, linkage means including universal connections for connecting one end of each support rod to said universal joint and the other end of each rod to a corresponding trail whereby substantially all forces of recoil and counterrecoil are absorbed by said firing platform, said universal joint permitting cant correction and 360 horizontal rotation of said gun carriage.

8. The combination in claim 7 and including a gun barrel fixed to a horizontal shaft trunnioned on said upper carriage, means including a gear train on said upper carriage for aiming said gun in elevation, and means including a gear train on said upper carriage and a segmental gear ring on said lower carriage for limiting rotation of said upper carriage.

9. The combination in claim 7 wherein said universal joint comprises a ball secured to said strut and received in a socket formed in the upper surface of said firing platform.

10. The combination in claim 7 and including a first spherically shaped plate having an upstanding peripheral wall secured to the upper surface of said firing platform, a second complementary spherically-shaped plate secured to saidstrut and intimately engaging said first named plate, said second plate having a diametral dimension to provide a small annular space between its peripheral surface and said upstanding wall, and cover means for securing said first and second plates together in sliding relation.

11. A- two-wheeled gun carriage for a mobile artillery piece comprising a lower carriage, an upper carriage, means. for rotatably supporting said upper carriage on saidlower carriage means on said lower carriage engaging said upper carriage and actuable to limit rotation of said upper carriage, a pair of trails each, having one end pivotally supported on said lower carriage, the other ends of? each said: trail adapted to be spread apart and to rest upon the ground when said gun carriage is in firing position, a firing platform carried by said lower carriage and adapted to rest up on the ground when said artillery piece is in firing position, means on said upper carriage for raising and lowering said'. firing platform, a universal joint connecting? said firing platform to said raising and lower ing means, and links providing a flexible and universal connection between said joint and said trails whereby substantially all forces of recoil and counter recoil are absorbed by said universal joint permitting cant connection and 360 horizontal rotation of said artillery piece.

12. The combination in claim 11 and includingv a gun;

barrel fixed to a horizontal shaft trunnioned on said upper carriage, means including a gear train on said upper carriage for aiming said gun in elevation, and means including a gear train on said upper carriage and a segmental gear ring on said lower carriage for limiting rotation of said upper carriage.

13. The combination in claim 11 wherein said universal joint comprises a ball secured to said strut and received in a socket formed in the upper surface of said firing platform.

14. The combination in claim 11 wherein said universal. joint includes a first spherically shaped plate having an upstanding. peripheral wall secured to the upper surface of said firing platform, a second complementary spherically-shaped plate secured to said strut and intimately engaging said first named plate, said second plate having a diametral dimension to provide a small annular spacebetween its peripheral surface and said upstanding wall, and cover means for securing said first and second plates together in sliding relation.

15. An artillery piece comprising a lower carriage, a pair of wheels supported on diametrically opposed sides of said lower carriage, an upper carriage, bearing means between said upper and lower carriage for supporting said upper carriage on said lower carriage for limited horizontal rotation, a gun barrel pivotally mounted on said upper carriage, a firing platform adapted to engage the ground when said artillery piece is in firing position, a strut, a universal joint connecting one end of said strut to said firing platform, crank mechanism rotatable about a horizontal shaft on said upper carriage, a ratchet mechanism for actuating said crank mechanism, and means pivotally connecting the other end of said strut to said crank mechanism whereby said platform is shifted from stowed position to firing position, said universal joint permitting cant correction and 360 horizontal rotation of said artillery piece.

16. In combination with an artillery piece, a lower carriage, an upper carriage mounted on said lower carriage for limited rotation relative thereto, a pair of trail members, means pivotally connecting one end of each said trail members to said lower carriage, a firing platform, means pivotal on said upper carriage and extending through. said lower carriage to provide a flexible connection with said firing platform, means on said upper carriage and including said flexible connection for moving said firing platform between stowed position adjacent the lower surface of said lower carriage and emplacement position on the ground, and means providing a universal connection between said firing platform and said flexible connection means whereby said gun may be corrected for cant and slewed about through 360.

17. In combination with an artillery piece, an annular support member forming a lower carriage, an upper carriage concentric within and rotatably mounted on said lower carriage, means on said lower carriage providing limited rotation of said upper carriage through a small angle, a strut, crank mechanism mounted for rotation about a horizontal shaftsupported on said upper carriage, means pivotally connecting the free end of said crank mechanism to one end of said strut, a firing platform adapted to support said artillery piece upon the ground, and means forming a universal connection between the upper surface of said firing platform and the other end of said strut, said last named means providing cant correction for said artillery piece and permitting rotation of said artillery piece through 360.

18. The combination of claim 17 and including, an emplacement member comprising a pair of divisible trails adapted to be spread apart when said artillery piece; is changed from travelling to firing position, each said trail member having one end adapted to be supported on the ground, and the other end pivotally mounted on said lower carriage, and support rods extending between each said trail and said strut, each said rod having one end providing a universal connection with said strut and the' other end providing a similar connection with a corresponding trail.

19. The combination of claim 17 and including a pair of wheels rotatably supported on said lower carriage.

20. The combination of claim 17 and including a firing piece supported on a horizontal shaft trunnioned on said upper carriage, and means on said carriage to aim said piece in elevation.

References Cited in the file of this patent UNITED STATES PATENTS 1,801,423 Goebert et al Apr. 21, 1931 1,894,680 Goebert Jan. 17, 1933 2,415,024 Allen Jan. 28, 1947 2,557,960 Gerhardt June 26, 1951 FOREIGN PATENTS 237,869 Great Britain Oct. 29, 1925 896,717 France May 2, 1944