US2454818A

US2454818A - Gun recoil spring surge dampener

Info

Publication number: US2454818A
Application number: US652754A
Authority: US
Inventors: Victor F Lucht
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-03-07
Filing date: 1946-03-07
Publication date: 1948-11-30
Anticipated expiration: 1965-11-30

Description

Nov. 30, 1948. v. F. LUCHT GUN RECOIL SPRING SURGE 'DAMPENER 3 Sheets-Sheet -1 H Filed March 7, 1946 y INVENTOR. BY V'clarFLuclzf ATTORNEYS Patented Nov. 30, 1948 "Vi t r Ln'cht, Washington, 1). ,o.

" The inventiomdescribeg-hereinmay lq ma u d diu eq b .Q TQ f Government for governmental pu poses; -vvithoutthe" payment' to This invention relates torecoil ncechanisins for guns; More particularly, the" invention relates' to improvements iii-"recoil mechanisms of" the type inflwhich the recoiFcylinder enclosesand-is' con centric with'thegun'tube."

As is' well-known to thosdskilled in-the art the recoil mechanism" in arr-artillery 'piece' is subjected to forces- 'and shocks of tremendous magnitude: In thefso-called' hydro-spring type ofufecoil'mechanism "a povverfulcoil spring is come pressed by recoil action of -the g un andth e energy stored' therein is utlli'zed to return the"; tube to battery; Ithas-beezi-foundthat springs; used in this type oirecoil" mechamsm sometimes fail prematurelybecause of uncontrolled action there; of in compression and; extension." In addition; the uncontrolledaction ofthe spring interferes with" smooth operation o'f -"the 'gu-n defect will i be experienced: "in eapons in} which the re coil mechanism ls separate from and parallel to the gun tube -as"- well" as in weapons in which the recoil mechanism is disposed concentrically with the-gun tub'e ia v H is particularly the 'c'ase in a:re-coi'l mechainism of the concentric type; some difficulty has beeni experienced"-in restraininga the guntube against a; twisting action that resultsi from the torque developed in the-tube when the 'proj'ec tile travels through the rifled barrels" Ill} the ordinary type of r-ecoil mechanism, 1 sufficient structure isprov-idediimtheform of thecr-adle or sleigh to accommodate? means -for restraining the gun tuber against the l action resulting from 'thisutorquei I'm the: case one: concentric recoil mechanism, the arrangementw is more compact and. the. problemziofzguidingithe gun .tube and re-. straining: the-ritub.e againstriitwistinfg isusomevvhat morezg liflicultza 'Inithe past, this :problem': has been solved? only ibyl meansvof additional structure at the breech endzofitherweapon'; Thezpresence ofsuch additional structure is not always desirable} since: it'increas'es' =:the ioverallilength'of the weapon andt ren'dersimor "difiicultth'e adaptation of the weapon. toiu'seznn aircraft ortanks or: other armored :vehicles 1 According "1702213118 present-"invention, means are p vid d:fori controlling undesirable action of the-i counterrecoilr spring asfi the: spring is com presst-idl andnextended uporr recoil and' counter recoil-1 of: the; gun; Thisi mean particular-1y con trolsia-surgin'gltithez-springtstain-gr of the amendedii'April 1928; 370 O. 7 57-) 2 spring occurs, upon initial rapid compression. of the springand the coils at one end of'the spring becomegrouped and impart longitudinal forces to adjacent coils'which likewise become grouped; coils'so grouped impart similar forces successively along the spring with the result that the force built-up prior to complete compression of the spring attains such magnitude that a reaction isset up and the forces and shocks travel toward the other end of the spring and thence back and forth from one end of the spring'to the other. It will be appreciated that surging occurs so rapidly that undesirable vibration can occur before the spring reaches the limit or its compression andin many cases results in prema-' thatsurging of the springis eliminated or kept 2 m nimumi It is an important object of the invention to. provide such means as a, component for the counterrecoilspringzof the'recoil mechanism of" an artillery. weapon. I

Anotherimportant object of the invention is to provide such means in a recoil mechanism of the type in which boththe recoil chamber and the counterrecoil spring are concentric with. the un'tube.

The invention has for another object the provision of a shock-absorbing. means for the counterr'e'coil spring-ofa recoilmechanisrmand another object-is to, combine. the shock-absorbing means with the surge-damping -means so that-op.- eration of the recoil' mechanism is accomplished more "smoothly. and efficiently.

It is; another. object of the invention toprovide dem n eans-in th f rm a plurality o s l fit el ments tha end; l n i d na l of the springoutsideithe coils thereofJ Yet anothe-r object-is to provide means onthe gun tube and cooperable' -'with the 'resilient *ele+ mer t; for: absorbing the torque imparted" to the gun barrel-by a projectile fired therefrom.

And still another object 1 of 1 the invention. is to provide. an improved" recoil-mechanism including second guid-e means for'nestrainingth'e gun tube against-the twisting action-that occurs when the gun is fired.

I The foregoing and other importantobjects and featuresof the invention may be had'frd the renew-me detailed description and accompanying sheets of drawings in which:

Fig. 1 is a plan view of a gun embodying a Fig. 4 is a transverse sectional view taken on the line 4-4! of Fig. 1;

Fig. 5 is a view taken from the breech end of the weapon and showing one of the guide means for absorbing torque imparted to the gun tube by a projectile fired from the gun;

Fig. 6 is a transverse sectional view taken stantially on the line 6-45 of Fig. 2;

Fig. 7 is a perspective view of the rear retaining ring for the surge-damping means;

Fig. 8 is a diagrammatic perspective view illustrating the manner in which the first and sec- 0nd, or primary and auxiliary, guide means function to restrain the gun tube against twistmg; l Fig.9 is a fragmentaryv longitudinal sectional view taken on the line 9+9 of Fig. 1 illustrating the manner in which the counterrecoil spring housing or sleeve is secured to the recoil cylinder; and

'Fig. 10 is an end view of the member that serves as a guide for restraining the gun. tube against twisting as Well asa means for retaining one end of the counterrecoil spring.

Figure 11 is an enlarged fragmentary sectional View showing the relationship between the buffer piston and the cylinder, v

Figure 12 is an enlarged end, partly in' section, of the ring springs assembly.

Although the preferred form of. the invention has been illustrated herein in connection with a recoil mechanism of the concentric type, it will be appreciated that several of the features thereof are similarly applicable to recoilmechanis'msof other types. Accordingly, the description and drawings should be taken as illustrative andlnot limiting.

In the type of weapon illustrated and described herein, the support for the gun comprises" a cylindrical housing or cradle formed at an exterior portion thereof "intermediate its ends with a pair of oppositely extending trunnions 2i These trunnions adapt the gun for mounting in aircraft, carriages, or tanks and other"'armored vehicles. The cylindrical housing 20 takes .the place of the cradle assembly that characterizes weapons of the type in. whiph the guntube and recoil mechanism are not concentric. As best shown in Fig. 3, the cylindrical housing is provided at opposite ends with interior annular bearings 22, at the breech or rear end, and 23, at the muzzleward or forward end. The bearing 22 is threaded'into the threaded rear end of the housing or cylinder 20 and is retained therein by a retaining screw 22. The forward end of the cylinder 20 is provided with a concentric annular recess 25 and, adjacent thisrecess and concentric therewith, is internally threaded as at 26. The bearing 23 comprises a sleeve which serves as the bearing and on which is formed an integral annular rib or flange 21. A circumferential flange 28 is formed integral with the rib 21 and is externally threaded to fit the internal threads 26 in the cylinder 20.

The gun tube or .barrel of the Weapon, indicated by the numeral 29, is carried for recoil and counterrecoil by the bearings 22 and 23. The bearings 22 and 23 include fluid-tight seals 30 and 3|, respectively. Thus the cylinder 22 is adapted to contain recoil oil or other suitable fluid in the annular chamber provided between the outer cylindrical surface of the tube 29 and the inner cylindrical surface of the cylinder. The

tube 29 is formed intermediate its ends within the cylinder 20 with a conical seat 32. A recoil piston means in the form of a ring 33 is provided with an internal conical seat complementary to the seat 32. That portion of the gun tube forwardly of the seat 32 is preferably formed with a series of square threads 34. An internally threaded sleeve is carried on the tube 29 by the threadedportion 34 and has its rear- Ward end' externally threaded to engage an internally threaded portion of the recoil piston 33 as at 36. An intermediate portion of the sleeve 35 is externallythreaded at 31 and carries a buffer piston inthe form of a ring- 38.; This ring is provided with a plurality of- ,circuniferentially spaced, axially directed bores "39 -'(only,one of which is shown) and, is held against rotating on the sleeve 35 by-means of a lockihgscrew 40. The forward-end of the sleeve, Hist-externally threaded and carriesa retaining'cap; ll. 'This cap isheld against rotation witlrrespect to, the sleeve 35 by means of alockingscrew 42. That portion ofthe sleeve-35 betweenthe-buffer piston 38 and cap 4| is annularlyreduced and there is thus formed onthe s1eeve35 anannular Sh0u1-. der #3. Valve means in the form ,ofa ring {24 is carried bythesleeve35 and is axially shiftable between the buifer piston 38-vand the cap 41. The forward end of the valve ring M3 is; formed with .a radially inwardly directed annular flange (l5. A-coil spring 46 encircles thereduced portion of the sleeve 35 and is confined-between the annular shoulder; 33 on the sleeve-3,5 and theannular flange: 4 5 onthe valve ring, l4 The actionof the spring filfi is such thatthe valvering M is normally maintained in the position shown in Fig. I QJ-JI. y

The cylinder 20 is provided at its breech end th tin structure elginc u ineav r r flange 48 to'which isrigidly attached a vertical flange 49 on a rearwardly extending guide plate 50. As best shown inFigs; 5 and 8gthe inner face of the guide plate 50 is formedlwith'a longitudinal channel or-groove 5!, The gum-tube '29 extends breechwardly through: the, rear bearing 22 of j the cylinder,20 and carries rigidlyithereon, a breech ring 52. The,right-hand"sideaofathe breech ring (as viewed from a position behind theigun) car-I ries rigidly thereonaguide element 53. As shown in Figs. 5 and 8, the guide ;elem ent:53 slidablyj engages the channel 5| in the guideiplat'eiiia Thus as the gun tube, recoils-and counterrecoils,' the guidingcomponents 5| and 53. prevent twistingof the gun tubeinresponse: -to'- torg ue-v imparted by the projectile as it travels? through nd leaves the rifled tube. 6.1

The recoil mechanism; .ofarwhichnthe" cylinder 20 forms a part,. is icompletedwby.counterrecoil mechanism which is disposedrcoaxiall-y, withthe cylinder 20, or concentrically ofzthei gun tube 29; and which is contained in ,a secondcylinder or sleeve 52. This sleeve is preferably; formed-of sheet metal'construction and. asyshown in Figs. 2 and 9, has rigidlysecured to-its rear or breeche ward end a mountingringi55, the extreme rear end of which is reduced and, threaded as at56.

sweaters anrannularseat 51- is providedpn the ring adj acentvugie-threaded-roma 5c. The sleeve ea is remevabiy carried by -the cylinder 213 and, when the parts-are assembled; the threaded portion 56 of 'the sleeve fit'sfthe internally threaded portion 26 of' the: Cylinder and the annular seat 51 fits the annular interna ecess" 25 of the cylinder. The sleeve 54 i's se'curedagainst rotation with respect tdth'e' cylinder-2'0 by means of a locking screw 58 'which is threaded through a section of the wail of'th'e eylinder tfl and engages a portion of the annular'seat-fil onthe mounting ring 55 of theisleeve- 5'4: (Fig. 9-);

The-interior of themounti-rig' ring 55- is formed with -a plurality of longitudinally directed, circuinrerenti'ally spaced slots 59 The ring is further formed with an internal integral annula'r 'rib' til which -includ'esa plurality of slots 61 coincident-iwith the sIots 59'(Fig'. '6) A retainer ring 6:2 Flg 7)* encircles the gun tube 29 and is positi 6. just forwardly of the annular Wall or rib 60in: the mounting ring 552 The ring fiz'is provided with a pair of diametrically opposed slots '63 and the diametrically opposed other sides ofthering'are flattened, as at 65 (Fig. '7). When the'parts' are assembled, the slots 63' are respectively aligned with the upper and lower slots '59- in the mounting ring 55 and the flat sides 64 he respectively radially inwardly of the slots 59'at opposite sides of the mounting ring 55 (Fig. 6). Thebody portion of .the ring 62 abuts the radi'al'face at'the forward end of the tube 'supporting bearing 23 (Fig. 9).

- A bearing sleeve-'65 encircles that portion of the gun tube 28: just forwardly of the ring 55 and carries the gun' tube for recoil and counterrecoil; The sleeve 65 includesair external annular radial flange 'GB against the rear face of which is seatedi'a flanged ring 6?. Asimilar ring 68, opposed to the'rin'gi 8-1; seats against the front radial face of'the' ring" 62". A sleeve Bilsurrounds the-cylindrical'portionsof the rings 67' and 68', anda plurality ofrring' springs 88' encircles the sleeve 69 between the radially flanged portions of therings 67 and1fi8; The unit comprising the rings 6'! and": 68', *the' sleeve 69, and the ring springs ill provides shock absorbing means for receiving-"amend?or a: coil-spring: 'H', the rear end:of:thespring'seatingiagainst the'radial flange 66 on the bearing? sleeve 65:

The"'forward"end of the spring "H is seated against a guide member 72', an annular radial wall 73. being-:rormedvas an integral part thereof tdi r'eceive or pilot the end of the spring. The guid'e12 is internally splined (Fig; and is carried on an externally 'splined portion 14 of th'e-'gun tube"29 (Fig- 2). The forward end of the spline- It on the gun tube 29- terminates in an annular groove formed in the gun tube 29'. A split; ring iii; preferably comprising two semicirct ilar halves'; iscontained by the'groove l5 and isfre'cessed -in thef'orw'ard end of the guide membei' -l2 That portion of the guide 12 that surrounds the-split ring it is externally threaded and receives a nut 17. 3 A-lockingpin 18' secures the nut Tagainstrota'tion with respect to the guide 72.- The guideme nber- '12 includes at'its rearward end ail-integral sleeve portion '19 which encirciesthe gun-"tube-fi'il and to: which is rigidly secured" a tubular-extension 8%.- The extension 86 -serv'es"toretainor pilot the forward end of the"counterrecoilspringl l i Iir' order thatthe' components'of the counterre coil mechanism--including theringsfiz' fi'i, 68; sleeve-'69; bearir'ig' sleeve 65* and spring ll may be easi yas'sembled and 1 disassembled; the for ware-enema the sleeve 55' is provided with an externalring 81; This ring is rigidly secured to the s1eeve--54i s'- bywelding'g'and is internally threaded" at 82. An internal nut-83', formed as a ring encircling a portion of the guide member 1 2, is 'threadedinto the threaded portion 82 of the-ring arena is held-therein against rotation by a 'lo'clring' pin 84;

The-threaded portioh 82 0f the ring BI is substantially't'w ice as long as the threaded portion o'i'tlie nut 83; -When the mechanism is assembled, the 'compon'ent's of the shock-absorbing unit are insert ed'fi'rst, followed by the's'pring l i" and guide 12 Tl'ie nut 83* is then threaded into the ring 8! and turned infuntil it engages the radial wall portion" F3 of the" guide i 21 This procedure compresses the spring H' and moves the guide 12 a sufii'ci-eiit distance rearwardly on the'g'un tube 29 to e ote" the split ring grooved'fi. The split ring le 'i's then fitted intothe'groo've 'i5'and the nut 83 is backed off" to the position shown in Fig, 2. The-compression or 'lo'a'd' of the-spring H is then taliei'rby'th'e' gun tube ZQthrOugh the guide 12 and thesplit-riii'g is: The'nut His threaded onto tlie'g-uide' lt and' is locked inplace by the pin it. The procedure just described is reversed when the niech'an'i'sm is disassembled. In short, indisas'sernbly', therir'i-g" 83-- is turned in until the split ring I6 is relieved of the leader the spring ll the ring 16" is subsequently removed.

As'statedpreviously;it has been found that uncontrolled surging i of the 'c'ounterrecoil spring interferes with the-smooth and'efficient' operation of the recoil mechanismi Accordingto the pres eri-tinvention means are provided for damping the surging action of the counterre'coil spring H. In its preferred form; this means comprises a plurality of longitudinally running resilient members in the former leaf springs 8-5 spaced circumferentially'about the interior of and rigidly secured to thesleeve 54, as-by rivets 86. These leaf springs-extend substantially throughout the lengt-h-ofthesleeveit and have their'free ends inserted'through-and retained by the slots 59in the mounting; ring -55.-- In the present instance, there are four such springs 85: The upper and lower springspass-through'the peripheral slots 63 iii-'theretainingring 62 and the springs at the right-hand and left-hand sides of the unit pass alongside the diametrically opposed flat sides 64 on the ringtZ; The rearward half of'each spring 85 is: curved-inwardly'a'nd then longitudinally so thatit lies in closepro'ximityto the outside dian1 eter-"of the counterrecoil spring "I l. The relationship between the spring H and the damper springs 85is such that frictional engagement be tween the'two' occurs when the former is compresseduponrecoil'of the gun tube 29. The tendency ofth'e'coils oi the'spring' to group and impart'suc'c'essive impulses to adjacent coils is restrained because of the action of the damper springs 85': Inother words, as the coils at the forward end of the'spring H tend to come togetherupon initial compression of the spring when theguntube recoils, the collection of forces normallyresulting from' such action is counteracte'd-b'y'the rearward portions of the springs 85'. Whereas; heretofore, the successively grouped ccils 'wou-ld'rebound'back andforth fronron'e end of 'the-spring tothe-other, such rebounding is now inhibitedby'- the- 'dampersprings 85, since, as the continuously enlarging group of coils reaches-the rearward portions of the leaf springs '85;fit is re tardd "and by the timethe-forc'es resultlng'froni see ers the piled up coils at the forward end of the spring reach the rearward end of the spring, the gun tube has recoiled sufiiciently to compress the spring to its maximum extent, at which point the spring H is fairly well packed and inherently resists surging.

Another important feature of the invention is the cooperation between the guide member I2 and the guide elements 5? and 53 previously described. The guide member :2 (Fig. is provided about its periphery with four equally spaced notches or slots 8?. The notches M are designed to cooperate with the damper springs 85 and provide complementary guide elements. The notches 81 are suficiently deep to accommodate the inwardly directed rearward portions of the springs 85 so that the guiding action is secured throughout the recoil and counterrecoil strokes.

The travel of the gun tube in recoil is substantially twice as long as the length of the channel 51 on the rear guide plate 50. Hence the guide plate 50 will serve to prevent twisting of the gun tube only during substantially the first half of the recoil action, after which the guide '53 on the breech ring 52 will escape the channel 5|. However, the gun tube is still held against twisting by means of the action of the guide 12 and damper springs 85. In short, the guiding action of the guide elements Elli and 5! is supplemented by the guiding action between the guide 72 and damper springs 85. Because of the high initial torque developed when the projectile is fired, it is desirable to include the guiding elements 50 and 5! rather than to depend on the guide Z2 alone. On

the other hand, the ability of the guide 12 to function as described permits economy in material and space, since the length of the guide plate 56 can be substantially reduced.

Operation When the weapon is fired and the gun tube recoils, the recoil piston 33 is forced rearwardly against the resistance of recoil oil contained in the cylinder 2i]. This oil is then forced from the rearward side of the piston 33 to the forward side thereof and a throttling action is effected as the oil escapes through the spaces between the edges of the

pistons

33 and 35 and the inner cylindrical surface of the cylinder 20, and thence through the bores or ports 39. the counterrecoil spring H is compressed. The initial shock is absorbed by the ring springs 10 and surging of the spring in is prevented by action of the damper springs 35, as previously described. The tendency of the gun tube to twist as the projectile is fired is resisted by action of the guide 53 on the breech ring 52 and channel 5! on the guide plate 50. As the gun tube continues to recoil, the spring H is more fully compressed. The guide 53 on the breech ring 52 will escape the channel 5! in the guide plate 50. However, the tendency of the tube to twist is still resisted by the cooperation between the guide 12 and damper springs 85. As the gun tube reaches its maximum recoiled position, the counterrecoil spring ii will be compressed to its maximum extent. The tendency of the spring to pack will be alleviated by the ring springs TIE! and there will be no violent shock. Reaction of the counterrecoil spring H will now return the gun tube to battery, during which phase of operation the recoil oil that is now at the front side of the piston will be forced to the rear side thereof. The presence of the oil at the front side of the chamber in the cylinder will cause the valve ring 44 to move rearwardly When the gun tube recoils, K

8 against the action of the valve spring 46 and-to close the bores or ports 39 in the buffer piston38. Consequently, the gun tube 29 returns to battery smoothly and easily. During travelof the gun tube in recoil, the valve ring 44 remains open, partly by action of the valve spring 46 and partly because of pressure of recoil oil as the oil is forced through the bores 39 in the louder piston 38.

One of the more important features of the invention, in addition to the structure and function of the surge-damping means and the means for preventing twisting of the gun tube, is the mounting of the recoil piston 33 directly on'the gun tube 29. In concentric recoil mechanisms of the type heretofore known, the recoil piston was mounted on a sleeve which in turn was connected to the breech end .of the gun tube. The recoil cylinder formerly included an intermediate sleeve portion which supported the gun tube'for movement in recoil and counterrecoil. According to the present invention, this expensive and additional structure is eliminated and the entire mechanism is simplified.

Still another feature incidental to the present invention is the location of the counterrecoil spring coaxial with and outside the recoil cylinder In earlier types of recoil mechanisms, whether of the concentric or eccentric type, it was customary to house the counterrecoil spring within the recoil cylinder. That design required a recoil of increased length. According to the present invention the length of the recoil cylinder 20 has been shortened. The locationof the spring H forwardly of the cylinder 28 does not undesirably increase the dimensions of the weapon, since the portion of the tube encircled by the spring 7! otherwise has no particular function in connection with operation of the recoil mechanism.

Other features of perhaps lesser importance will be apparent to those skilled in the art. It will be understood, of course, that the form of the invention illustrated and described herein is a preferred embodiment and that numerous modifications and alterations may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a recoiling gun, a cylindrical cradle fixed against recoil and counterrecoil and provided with interior bearing elements, a gun tube mounted concentrically within said cradle and slidably carried by said bearing elements for recoil and counterrecoil, a breech ring on said gun tube, a support fixedly mounted on said cradle and extending breechwardly alongside said breech ring, first cooperable guide elements carried respectively by said breech ring and said support and relatively slidable in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube on its axis with respect to said cradle, the brcechward extent of the interlocking effectiveness of said guide elements being less than the length of the recoil stroke of said gun tube, and second cooperable guideelements carried respectively by said gun tube and said cradle muzzlewardly of said first guide elements and relatively slidable in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube about its axis with respect to said cradle, said second guide elements being arranged to take effect prior to the end of the effectveness of said first guide elements and to continue effective during completion of the recoil stroke.

2. In a recoiling gun, a gun cradle fixed against recoil and counterrecoil, aigun tube slidablyicarried by saidcradle for recoil ,andjcounterrecoil, a breech ring on said :gun tube, a support fixedly mounted on, said cradle. and extending .zbreechwardly alongside said breech ring, :fiISt, cooperable guide elements carried respectivelybysaidbreech ringand said supportand relatively slidable in the directions of recoil and counterrecoil but interlockable against twistingactioncf said guntube on its axis with respect to said .cradle,1-the breech ward extent ,ofthe. interlocking vefiectiveness; of said guide elements being less "than the length of the recoil stroke of saidgun tube;.and.second cooperable guide elements carried respectively by said gun tube and said cradlermuzzlewardly. of said first guide elements and relatively slidable in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube about its axis, withrespect ,tosaid cradle, said second guide elements being arranged to take effect prior to the end of the efiectiveness of said first guide elements and to continue effective during completion of the recoil stroke.

in a recoiling gun, a cylindrical cradle fixed against recoil and counterreooil and provided with interior bearing elements, a gun tube mounted concentrically within said cradle and slidably carried by said bearing elements for recoil and counterrecoil, a breechring on ,said gun tube, a support fixedly mountedon said cradle and extending vbreechwardly alongside said breech ring, main cooperable guideelements carried respectively by said breech ring and said support and relatively slidable in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tubeion-its-axis with respect to said cradle, h reecbwa dexte f :thei to ns fi c enesscf saidvsuide elements being less than the length of the recoil Stroke ,of said gun tube, a sleeve fixed on said cradle :ccncentric therewith at its muzzleward end encircling said gun tube, a first auxiliary guide member carried by said sleeve, a second auxiliary guide member carried by said gun tube and positioned with respect to and for cooperation with said first guide member for relative sliding movement in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube on its axis with respect to said cradle, said auxiliary guide members being arranged to take efiect prior to the end of the effectiveness of said first guide elements and to continue efiective during completion of the recoil stroke.

i. In a recoiling gun, a gun cradle fixed against recoil and counterrecoil, a gun tube slidably carried by said cradle for recoil and counterrecoil, a support fixedly mounted on said cradle and extending breechwardly alongside said breech ring, first cooperable guide elements carried respectively by said breech ring and said support and relatively slidable in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube on its axis with respect to said cradle, the breechward extent of the interlocking effectiveness of said guide elements being less than the length of the recoil strokeof said gun tube, a sleeve fixed on said cradle concentric therewith at its muzzleward end and encircling said gun tube, a first auxiliary guide memoer carried by said sleeve, a second auxiliary guide member carried by said gun tube and positioned with respect to and for cooperation with said first guide member for relative sliding movement in the directions of recoil and counterrecoil but interlockable against twisting of said gun tube on itsaxis with respect to said cradle, said auxiliary guide members being arranged to take effect prior to the end of the effectiveness of said first guide elements and to continue effective during completion of the recoil stroke.

5. In a recoiling gun, a cylindrical cradle fixed against recoil and counterrecoil and provided with interior bearing elements, a gun tube mounted concentrically within said cradle and slidably carried by said bearing elements for recoil and'counterrecoil, a breech ring on said gun tube, a support fixedly mounted on said cradle and extending breechwardly alongside said breechring, first cooperable guideelements carried respectively by said breech ring and said support and relatively slidable in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube onits axis with respect to said cradle, the breechward extent ,of the interlocking effectiveness of said guideelements being less than the length of the recoil stroke of said gun tube, a coiled compression spring encircling said gun tube at a portion of said cradle muzzlewardly' of said breech ring,

meansonsaid oradleagainst which one end oi";

said spring abuts, an abutment secured. to said gun tube ,andq-abutting the other end of said spring for compression of said spring during recoil of the gun tube, and second guide elements respectively on said sleeve, and said abutment and cooperable for relative sliding in the :directions of recoil and counterrecoil but interlockable against twistingv action of said gun tube on its axis with respect to said cradle, said second guide elements being arranged to take effect prior to the end ofthe effectiveness of said first guide elements and to continue effective during completion of the recoillstroke.

6.- ma recoiling gun, a gun cradle fixed against recoil and counterrecoil, a gun tube slidably carried by-saidcradle for recoil and counterrecoil, a breech ring on said gun tube, a support fixedly mounted on said cradle and extending breechwardly alongside said breech ring, first cooperable guide elements carried respectively by said breech ring and said support and relatively slidable in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube on its axis with respect to said cradle, the breechward extent of the interlocking effectiveness of said guide elements being less than the length of the recoil stroke of said gun tube, a coiled compression spring encircling said gun tube muzzlewardly of said breech ring, means on said cradle against which one end of said spring abuts, an abutment secured to said gun tube and abutting the other end of said spring for compression of said spring during recoil of the gun tube, and second guide elements respectively on said sleeve and said abutment and cooperable for relative sliding in the directions of recoil and counterrecoil but interlockable against twisting of said gun tube on its axis with respect to said cradle, said second guide elements being arranged to take effect prior to the end of the effectiveness of said first guide elements and to continue effective during completion of the recoil stroke.

'7. In a recoiling gun, a cylindrical cradle fixed against recoil and counterrecoil and provided with interior bearing elements, a gun tube mounted concentrically within said cradle and slidably carried by said bearing elements for recoil and counterrecoil, a breech ring on said gun tube, a support fixedly mounted on said cradle 11. and extending breechwardly alongside said breech ring, first cooperable guide elements carried respectively by said breech ring and said support and relatively slidable in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube on its axis with respect to said cradle, the breechward extent of the interlocking efiectiveness of said guide elements being less than the length of the recoil stroke of said gun tube, a sleeve fixed on said cradle concentric therewith at its muzzleward end and encircling said gun tube, a coiled compression spring encircling said gun tube and enclosed by said sleeve at a portion of said cradle muzzlewardly of said breech ring, means on said cradle against which one end of said spring abuts,,an abutment secured to said gun tube and abutting the other end of said spring for compression of said spring during recoil of the gun tube, a plurality of leaf springs carried by said sleeve at its interior and extending mu'z-- zlewardly and engageable with said coil spring to dampen surging thereof, and a guide on said sleeve and cooperable'with said leaf springs for relative sliding in the directions of recoil and counterrecoil but interlockable against twisting action of said gun tube on its axis with respect to said cradle, said abutment and leaf springs being arranged to take effect prior to the end of the effectiveness of said first guide elements and to continue effective during completion of the recoil stroke.

8. In a recoiling gun, a cylindrical cradle fixed against recoil and counterrecoil and provided with interior bearing elements, a gun tube mounted concentrically within said cradle and slidably carried by said bearing elements for recoil and counterrecoil, a breech ring on said gun tube, a sleeve fixed on said cradle concentric therewith at its muzzleward end and encircling said gun tube, a coiled compression spring en- 12 circling said gun tube and enclosed by said sleeve at a portion of said cradle muzzlewardly of said breech ring, means on said cradle against which one end of said spring abuts, an abutment secured to said gun tube and abutting the other end of said spring for compression of said spring during recoil of the gun tube, a plurality of leaf springs carried by said sleeve at its interior and extending muzzlewardly and engageable with said coil spring to dampen surging thereof, and a guide on said sleeve and cooperable with said leaf springs for relative sliding in the directions of recoil and counterrecoil but interlockable against twisting of said gun tube on its axis with respect to said cradle.

VICTOR F. LUCHT.

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

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