US2409637A - Muzzle closing mechanism - Google Patents

Description

22, 1946- v. F. LUCHT ,MUZZLE CLOSING MECHANISM Filed June 2, 1945 2 Sheet`s-Sheet l @u .Q v .Y m -mk mmm. mm V llll h. 4|. BDN MN .AMY m:\ LI. QIV f om. III|| .l www m umm @v L Q Q S Iv Vctor F. Lucht v v. F. LUCHT MUZZLE CLOSING MEC'HANISM Filed June 2, 1943 2 Shee'S-Sheet 2 Patented Oct. 22, l1946 UNITED STATES PTENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 10 Claims.

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

This invention relates to muzzle closing devices for guns of fairly large calibre, for example, '75 mm. and more particularly, for aircraft-carried guns of this calibre range. Such guns because of their size and weight and the force of `their recoil, are usually placed in the fuselage of the aircraft and fire forwardly of the plane. Under such conditions the air ow aft'of the plane blows through the gun barrel when the breech is opened into the cockpit of the aircraft. Considerable of the toxic gases of the products of the explosion remain in the gun barrel upon the ring of a shell, and are carried with the indraft of air through the breech when it is opened following the gun discharge. The gas entering the cockpit is especially injurious to the crew because of the enclosed nature of the cockpit and the confined space thereof.

The object of this invention is to provide a muzzle closing device which would rectify this condition by closing the muzzle to the air stream except when the gun is fired, at which time the breech is of course closed, so that there will be no air inrush during firing. Allied with this object, a further object is to provide a muzzle closing device which will close the muzzle immediately after its discharge, at which time there will be the maximum residue of toxic gases in the barrel; moreover, the breech is soon after opened for reloading and would permit such gases to be blown into the cockpit were the muzzle allowed to remain open to the air flow.

For the attainment of these and such other objects of invention as may herein appear or be pointed out, I have shown an embodiment of my invention in the accompanying drawings, where- Fig. 1 is a top view of a gun showing the muzzle device in closed condition;

Fig. 2 is a longitudinal section throughv thev gun, with the muzzle device in closed condition;

Fig. 3 is likewise a longitudinal section, but with the muzzle device in open condition;

Fig. 4 is a cross-section taken on the line 4 4 of Fig.2;

Figs. 5a to 5f are schematic illustrations referred to in the specification as an aid to explain the operation of the device;

Figs. 6 and l are detail views of a segmental blade forming part of the muzzle closing assemblagc;

Fig. 3 is a cross-section on line 8-8 of Fig. 2;

Fig. 9 is an enlarged detail of the V-notched finger, and

Figs. 10 and l1 illustrate the mechanically operated electric switch referred to herein.

The muzzle-closer comprises a number, four being shown in the drawings by way of example, of segmentary numbers IU which come together in the closing condition of the device, as shown in Fig. 1 and Fig. 2, in the fashion of a clamshell bucket. Each of the segmentary members is provided internally with an inclined cam surface to engage the gun barrel, as shown in Figure 3, for a purpose to appear and is pivoted at pin I2 to an annular` member I4 which is secured at the muzzle end of a long tubular member I5. To provide for the said pivoting of the segmentary members I0 to the said annular member I4, the segmentary members are provided on their inner surface with an L-shaped lug I I, the distal end of which is apertured for the said pivot pin I2. The tubular member I5 is spaced from the gun barrel I, see Figs. 2 and 3, a sufficient distance to provide clearance for an internally splined tube I6 which is secured, at or near the midpoint of tubular member I5, to the internal face thereof. The internally disposed serrations, i. e. teeth elements and channels, of the splined tube I6 are clearly seen in Fig. 4. An external splined ring B secured to the gun barrel I is provided with teeth which are receivable in the grooves of the internally splined tube I6 and the teeth of the latter are receivable in the channels of the external splined ring 6. It should be noted that the internally splined member I6 secured to the inner surface of the annular tubular member I 5 is of considerable length-hence herein termed a tube-com pared to the externally splined member 6 secured to the outer surface of the gun barrel-hence herein termed a ring Tubular member I5 together with its annular head I 4 and the segmentary closing members pivoted thereon, and together with the internally splined tube I6 are longitudinally movable from the muzzle-closing position, shown in Fig. 2,

rightwardly to the muzzle-opening position ofY Fig. 3, and return in the opposite direction. In this longitudinal adjustment, tubular` member I5 moves between gun barrel I and an outer tubular member 25 which is secured at its right end, to the breech casing 2 of the gun.

Slidable tubular member I5 is provided at its right end with a pair of diametrically opposite pins I3, see Fig. 2, which protrude through elongated slots 23 provided in the stationary tubular d member 25. A tensile spring E53, one for each of the two pins, is secured to the pin I3, the other end being ancho-red to a small bracket 25a on the stationary tubular member 25. As clearly seen in Fig. l, elongated slot 23 is wider than the thickness of pin I3, so that the tubular member I5, to which the pins I3 are secured, as described, has an extent of angular or rotational adjustment. More particularly, tubular member I5 has two positions of angular adjustment, one, in which the teeth of the splined tube I 6, which is secured internally to the tubular member i5, as described, are aligned with the intermediate spaces of the splined ring 5, which is secured externally to the gun barrel i, as described, as shown in Fig. 4.

The normal position of the tubular member i5, i. e., with the muzzle-closer II) in closing position, as in Fig. l, is diagrammatically shown in Fig. 5a. The tubular member I5 is in forward or muzzle-ward position, to the left in the figures, with its pin I3 at the left end of slot 23, as seen in Fig. 5a; it is also in the angular position in which the teeth of the splined ring I5 abut the teeth of the splined tube iii. In this position, teeth act as stops preventing the rearward movement of the tubular member i6, thus maintaining the muzzle-closer i@ in closing position. In this position of the parts, see Fig. 5a, the pin I3 is disposed at the upper, as viewed in Figs. 5u and l, edge of slot 2S, and is maintained in this position by means oi a V-notched nger 2S pivotally mounted on the stationary tubular member 25 at ZOU.. As best shown in Fig. l, the crotch of the V-notch is positioned at or near the upper edge of slot 23 to maintain pin i3 at that edge. The V-iinger 2S has a short arm ZI to which is articulated the left end of a long rod 22, the right end of which is located at the breech end of the gun, to the right in Figs. 1 3 and is slidably guided in a sleeve secured to the stationary tubular member Rod terminates in a knob 22.76 in close proximity to the breech elevating mechanism designated generally as 3S. Between knob 22k and the right end of frame sleeve 2S is a compression spring 22s; which normally urges rod 22 rightwardly, to maintain nger lever 2v2 turned in a counterclock'wise sense, with its V-notch aligned with the upper edge of slot 23, as shown in Fig. l.

In the normal condition of the parts, as shown in Fig. 5a, the spring 55 is under tension tending to pull the pin i3 associated with the tubular member i5 rightward but is blocked by the abutment of the teeth It of the splined tube, likewise associated with the tubular member I5, with the teeth 6 of the splined ring associated with the gun barrel. In this normal position of pin I3 at the left of slot 23, Fig. 5a, the muzzle-closer Ii! is maintained in closed position. To bring the muzzle-closer 53 to its open position-preparatory to discharging the gunknob 22k is caused to be moved. to the left, to move rod 22 in that direction, causing finger Vlever 2i! to be turned clockwise and its V-notch to cam pin I3 toward the lower edge of slotl 23 as shown in Fig. 5b. VThe knob 2tlg; is pushed leftwardly by the breech elevating mechanism 39, Fig. 1, more particularly by a movable part thereof, such as the rod "5I shown in Figi. 1. As the breech block is elevated (not shown) the compressed spring SIS associated with mechanism 3G causes rod SI to move leftwardly. Y

In this position, Fig. 5b, of tubular member I5, turned angularly by its pin I3, tubular member I5 turns slightly in a clockwise direction, as

4 shown by arrow a, Fig. 4, or rather by the said operation of finger lever 2S, spline teeth I6 are moved out of abutting alignment with the teeth of the spline ring 6 associated with the gun barrel. The teeth It no longer being blocked by the barrel teeth ii, the tubular member I5 is moved rightwardly by tensioned spring 55s. This rightward movement of tubular member I5 causes the internal cam surface of the members IG to ride over the gun barrel end forcing the muzzle device IE to be moved to open position, Fig. 3. The pin I3 associated with the tubular member i5 therefore moves rightwardly towards the right end of slot 2t to the position at its right end shown in Fig. 5c. rIhe right end of slot 23 is provided with an inclined surface 2e, which is effective to move the pin I! upwardly if the pin were continued to be moved rightwardly. However, at this time, Fig. 5c, upward movement of pin i5, i. e., counterclockise turning of tubular member I5, arrow b, Fig. e, is prevented by the teeth 6 of the splined ring associated with the gun barrel. The parts are thus left in the condition shown in Fig, 5c, with the muzzel device I@ in open position.

The gun is now fired, the recoil causing the teeth 6 associated with the gun barrel to move righ*- wardly as shown in Fig. 503. The rightward movement of the gun barrel in recoil causes the teeth of the spline ring associated with the gun barrel to be moved rightwardly out of blocking engagernent with the teeth I6 of the spline ring associated Iwith the tubular member, as shown in Y Fig. 5d, with the result that pin I3 moves up the incline, as shown in Fig. 5e, the tubular member i5 turning in 'a counterclcckwise direction, arrow b Fig. 4. This turning of tubular member I5 brings the teeth I of the splined tube again in alignment with the teeth of the splined tube, as shown in Fig. 5e. Subsequently upon the counter-recoil movement of the barrel, leitwardly in the figures, the teeth 8 of the splined ring associated with the gun barrel moves the tubular member I5, by moving its associated i' spline teeth "It, to the left, as shown in 5f, thus moving the muzzle device to closed condition, with the tubular member I5 in its leftward position, Figure 2.

Details of the muzzle-closing device Il are shown in Fig. 8. The segment pieces Iii, pivoted on pins I2 of the annular head if?, as previously explained and shown in Fig. 2, are connected to one another by tensile springs IGS which are effective when the muzzle closing device, i. e., segments Il, is moved, by movement of the said annular ring Iii of the tubular member I5, beyond the muzzle, as in Fig. 2, to draw the segments I together to closed condition as shown in the said iigure. To avoid the possibility of ring the gun when the muzzle device is in closed position, which might occur upon the breaking of an opative part or because of some other mishap, an electrical switch 4D, Figs. l0 and 1l, is provided in the electrical circuit associated with the nring mechanism (not shown). Switch 4B has a roller il which clears through a hole Z8 provided in outer tubular member '25. When the inner tubular member I5 is in its rightward position, Fig. 11, at which time the muzzle device i's in open condition, the roller 4I is caused to ride on the member I5, being thus moved upwardly to close the switch di), i. e., to permit thev gun to vbe discharged, inasmuch as the muzzle device is in open position. When however, the tubular member I5 moves to the left, to the position shown in Fig. l0, the roller il drops oir. the tubular member and opens the switch d0, thus opening the primer circuit, inasmuch as the muzzledevice is now in closed condition.

I claim; Y

l. In a muzzle closing device for a gun, in combination, a tubular member slidably mounted on the gun barrel and adapted to turn through a limited angle, a member secured internally to the said tubular member and itself internally splined, Ya ring member s-tationarily secured to the gun barrel and externally splined, the teeth of the said splined member clearing through the interdental spaces of the said stationary spline ring in one angular position of the tubular slide member and blocked by the teeth of the stationary spline ring in a second angular position of the tubular slide member, a second tubular member stationarily secured to the gun breech and provided with an elongated slot having an inclined cam surface at its breech-end, a pin eX- ternally projecting from the first-mentioned tubular slide member and received in the lelongated slot of the second-mentioned stationary tubular member, the said slot being suiiciently wide to permit the pin to be turned the said limited angle of tubular slide member turning and sufciently long to permit the pin to be moved with the tubular slide member a distance somewhat greater than the length of the said splined member of the tubular slide member, muzzle closing means at the muzzle-end of the tubular slide member, a tensile spring secured to the said pin and anchored on the said stationary tubular member tensioned to urge the tubular slide breech-ward to move the said muzzle closing means to open position, a forked lever pivotally mounted at the muzzle-end of the elongated slot with the said pin of the tubular slide member received in its fork whereby the tubular slide member is normally maintained in its second vsaid angular position with its spline teeth blocked against breech-ward movement of the tubular slide member under urgency of the said spring, by the spline teeth of the stationary spline ring, means for turning the said forked lever to turn the tubular slide member to its first said angular position with its spline teeth clearing in the interdental spaces of the stationary spline ring, whereat the said tensile spring moves the tubular slide member breech-ward, the said muzzle closing means being moved to open position and the said pin approaching the said cam surface end of the elongated slot, the spline teeth of the tubular slide member being engaged by the spline teeth of the said stationary spline ring to prevent turning of the tubular slide member, the said spline teeth of the spline ring being moved with the gun barrel on recoil breech-ward beyond the spline teeth of the tubular slide member', the said pin of the tubular slide member riding on the said cam surface of the elongated slot whereby the tubular slide member is turned to the second said angular position with the spline teeth in blocking alignment, the teeth of the said spline ring engaging the teeth of the tubular slide member upon counter-recoil to move the tubular slide member muzzle-ward, to bring the said muzzle closing means to closed position, the said pin of the tubular slide member engaging the said forked lever to maintain the tubular slide member in the second said angular position, with the tubular slide member blocked by the abutment of its spline teeth with theV teeth` oi the spline ring against breech-ward movement of the tubular slide member and with the muzzle closing means maintained in closed condition.

2. In a muzzle closing device for a gun, inv combination, a tubular member slidably mounted on the gun barrel and adapted to turn through a limited angle, the said member being internally splined, a ring member stationarily securedto the gun barrel and externally splined, the teeth of the said tubular slide member clearing through the interdental spaces of the said stationary spline ring in one angular position of the tubular slide member and blocked by the teeth. of the stationary spline ring in a second' angular position of the tubular slide member, a second tubular member stationarily secured to the gun breech and provided with an elongated slot having an inclined cam surface at itsbreecheend, a pin externally projecting from the inst-mentioned tubular slide member and received in f the elongated slot of the second-mentioned stationary tubular member, the said slot being sufficiently wide to permit the pin to be vturned the said limited angle of tubular slide member turn ing and suciently long to permit the pin to be moved with the tubular slide member a distance somewhat greater than the length of the said spline teeth of the tubular slide member, muzzle closing means at the muzzle-end of the tubular slide member, a tensile spring secured to the said pin and anchored on the said stationary tubular member tensioned to urge the tubular slide breech-ward to move the said muzzle closing means to open position, a forked lever pivotally mounted at the muzzle-end of the elongated slot with the said pin of the tubular slide member received in its fork whereby the tubular slide member is normally maintained in its second said angular position with its spline teeth blocked against breech-ward movement of the tubular slide member under urgency of the said spring by the spline teeth of the stationary spline ring, means for turning the said forked lever to turn the tubular slide member to its first said angular position with its spline teeth clearing in the interdental spaces of the stationary spline ring, whereat the said tensile spring moves the tubular slide member breech-ward, the said muzzle closing means being moved to open position and the said pin approaching the said cam surface end of the elongated slot, the spline teeth of the tubular slide member being engaged by the spline teeth of the said stationary spline ring to prevent turning offthe tubular slide member, the said spline teeth of the spline ring being moved with the gun barrel on recoil breech-ward beyond the spline teeth of the tubular slide member, the said pin of the tubular slide member riding on the said cam surface of the elongated slot whereby the tubular slide member is turned to the second said angular position with the teeth of the spline ring in blocking alignment with the spline teeth of the tubular slide member, the teeth of the said spline ring engaging the teeth of the tubular slide member upon counter-recoil to move the tubular slide member muzzle-ward, to bring the said muzzle closing means to closed position, the said pin of the tubular slide member being received in the said forked lever to maintain the tubular slide member in the second said angular position, with the tubular slide member blocked by the abutment of its spline teeth with the teeth of the spline ring against breech-ward movement of the tubular slide member'and with the muzzle closing means maintained in closed condition.

3. In a muzzle closing device for a gun, in combination, a tubular members slibaly mounted on the gun barrel and adapted to turn through a limited angle', a member secured internally to the said tubular member and itself internally splined, a ring member stationarily secured to the gun barrel and externally splined, the teeth of the said splined member clearing through the interdental spaces of the said stationary spline ring in one angular position of the tubular slide member and blocked by the teeth of the stationary spline ring in a second angular position of the tubular slide member, a second tubular member stationarily secured to the gun breech and provided with an elongated slot having an inclined cam surface at its breech-end, a pin externally projecting from the first-mentioned tubular slidemember and received in the elongated slot of the second-mentioned stationary tubular member, the said slot being suiiciently'wide to permit the pin to be turned the said limited angle of tubular slide member turning and sufficiently long to permit the pin to be moved with the tubular slide member a distance somewhat greater than the length of the said splined member of the tubular slide member, muzzle closing means at the muzzle-end of the tubular slide member, a tensile spring secured to the said pin and anchored on the said stationary tubular member tensioned to urge the tubular slide breech-Ward to move the said muzzle closing means to open position, a forked lever pivotally mounted at the muzzle-end of the elongated slot with the said pin of the tubular slide member received in its fork whereby the tubular slide member is normally maintained in its second said angular position with its spline teeth blocked against breech-Ward movement of the tubular slide member under urgency of the said spring, by the spline teeth of the stationary spline ring, means for turning the said forked lever to turn the tubular slide member to its irst said angular position with its spline teeth clearing in the interdental spaces of the stationary spline ring, whereat the said tensile spring moves the tubular slide member breech-ward, the said muzzle closing means being moved to open position and the said pin approaching `the said cam surface end of the elongated slot, the spline teeth of the tubular slide member being engaged by the spline teeth of the said stationary spline ring to prevent turning of the tubular slide member, the said spline teeth of the spline ring being moved with the gun barrel on recoil breech-Ward beyond the spline teeth of the tubular slide member, the said pin of the tubular slide member riding on the said cam surface of the elongated slot whereby the tubular slide member is turned to the second said angular position with the spline teeth in blocking alignment, the teeth of the said spline ring engaging the teeth of the tubular slide member upon counter-recoil to move the tubular slide member muzzle-Ward, to bring the said muzzle closing means to closed position, the said p-in oi the tubular slide member engaging the said forked lever to maintain the tubular slide member in the second said angular position, with the tubular slide member blocked by the abutment of its spline teeth with the teeth of the spline ring against breech-ward movement of the tubular slide member and with the muzzle closing means maintained in closed condition, and means operated by the breech block mechanism of the gun for turning the said forked lever.

4. In a muzzle closing device for a gun, in com'- bination, a tubular member slidably mounted on the gun barrel and adapted to turn through a limited angle, the said member being internally splined, a ring member stationarily secured to the gun'barrel and externally splined, the teeth of the said tubular slide member clearing through theinterdentalspaces of the said stationary spline ring in one angular position of the tubular slide member and blocked by the teeth of the stationary spline ring in a second angular position of the tubular slide member, a second tubular member stationarily secured to the gun breech and provided with an elongated slot having an inclined cam surface at its breech-end, a pin externally projecting from the inst-mentioned tubular slide 'member and received in the elongated slot of the second-mentionedstationarytubular member, the said slot being suiiiciently wide to permit the pin to be turned the said limited angle of tubular slide member turning and suliciently long to permit the pin to be moved with the tubular slide member a distance somewhat greater than the length of the said spline teeth of the tubular slide member, muzzle closing means at the muzzle-end of the tubular slide member, a tensile spring secured to the said pin and anchored on the said stationary tubular member tensioned to urge the tubular slide breech-Ward to move the said muzzle closing means to open position, a forked lever pivotally mounted at the muzzle-end of the elongated slot with the said pin of the tubular Vslide member received in its fork whereby the tubular slide member is normally maintained in its second said angular position with its spline teeth blocked against breech-Ward movement of the tubular slide member under urgency of the said spring by the spline teeth of the stationary spline ring, means for turning the said forked lever to turn the tubular slide member to its nrst said angular position with its spline teeth clearing in the interdental spaces of the stationary spline ring, Whereat the said tensile spring moves the tubular slide member breech-Ward, the said muzzle closing means being moved toopen position and the said pin approaching the said cam surface end of the elongated slot, the spline teeth of the tubular slide member being engaged by the spline teeth of the said stationary spline ring to prevent turning of the tubular slide member, the said spline teeth of the spline ring being moved with the gun barrel on recoil breech-Ward beyond the spline teeth of the tubular slide member, the said pin of the tubular slide member riding on the said cam surface of the elongated slot whereby the tubular slide member is turned to the second said angular position with the teeth of the spline ring in blocking alignment with the spline teeth of the tubular slide member, the teeth of the said spline ring engaging the teeth of the tubular slide member upon counter-recoil to move the tubular slide member muzzle-Ward, to bring the said muzzle closing means to closed position, the said pin of the tubular slide member being received in the said forked lever to maintain the tubular slide member in the second said angular position, with the tubular slide member blocked. by the abutment of its spline teeth with the teeth of the spline ring against breech-Ward movement of the tubular slide member and with the muzzle closing means maintained in closed condition, andmeans operated by the breech block mechanism of the gun for turning the said forked lever.

5. In a muzzle closing device for a gun, in combination, a tubular member slidably mounted on 9 the gun barrel and adapted to turn through a limited angle, the said member being internally splined, a ring member stationarily secured to the gun barrel and externally splined, the teeth of the said tubular slide member clearing through the interdental spaces of the said stationary spline ring in one angular position of the tubular slide..

member and blocked by the teeth of the stationary spline ring in a second angular position of the tubular slide member, a second tubular member stationarily secured to the gun breech and provided with an elongated slot having an inclined cam surface at its breech-end, a pin externally projecting from the iirst-mentioned tubular slide member and received in the elongated slot of the second-mentioned stationary tubular member, the said slot being sufliciently wide to permit the pin to be turned the said limited angle of tubular slide member turning and sufficiently long to permit the pin to be moved with the tubular slide member a distance somewhat greater than the length of the said spline teeth of the tubular slide member, muzzle closing means at the muzzle-end of the tubular slide member, a tensile spring secured to the said pin and anchored on the said stationary tubular member tensioned to urge the tubular slide breech-ward to move the said muzzle closing means to open position, means engaging the said pin for normally maintaining the said tubular slide member in its second said angular position with its spline teeth blocked by the spline teeth of the stationary spline ring, means for operating the said pin engaging means to turn the tubular slide member to its rst said angular position with its spline teeth clearing in the interdental spaces of the stationary spline ring, Whereat the said tensile spring movesthe tubular slide member breech-Ward, the said muzzle closing means being moved to open position and the said pin approaching the said cam surface end ofthe elon gated slot, the spline teeth of the tubular slide member being engaged by the spline teeth of the said stationary spline ring to prevent turning of the tubular slide member, the said spline teeth of the spline ring being moved with the gun barrel on recoil breech-ward beyond the spline teeth of the tubular slide member, the said pin of the tubular slide member riding on the said cam surface of the elongated slot whereby the tubular slide member is turned to the second said angular position with the teeth of the spline ring in blocking alignment with the spline teeth of the tubular slide member, the teeth of the said spline ring engaging the teeth of the tubular slide member upon counter-recoil to move the tubular slide member muzzleeWard, to bring the said muzzle closing means to closed position, the said pin of the tubular slide iember being received in the said pin engaging means to maintain the tubular slide member in the second said angular position, with the tubular slide member blocked by the abutment of its spline teeth with the teeth of the spline ring against breech-ward movement of the tubular slide member and with the muzzle closing means maintained in closed condition.

6. 1n a muzzle closing device for a gun, in combination, a tubular member slidably mounted on the gun barrel and adapted to turn through a limited angle, the said member being internally splined, ring member stationarily secured to the gun barrel and externally splined, the teeth of the said tubular slide member clearing through the interdental spaces of the said stationary spline ring in one angular position or" the tubular slide member and blocked by the teeth of the stationary spline ring in a second angular position `of the tubular slide member, a second tubular member stationarily secured to the gun breech and provided with an elongated slot having an inelined cam surface at its breech-end, a pin externally projecting from the first-mentioned tubular slide member and received in the elongated slot of the second-mentioned stationary tubular member, the lsaid slot being suiiiciently Wide to permit the pin to be turned the said limited angle of tubular slide member turning and sufficiently long to permit the pin to be moved with the tubular slide member a distance somewhat greater than the length of the said spline teeth of the tubular slide member, muzzle closing means at the muzzle-end of the tubularslide member, a tensile spring secured to the said pin and `anchored on the said stationary tubular member tensioned to urge the tubular slide breech-Ward to move the said muzzle closing means to open position, means engaging the said pin for normally maintaining the said tubular slide member in its second said angular position with its spline teeth blocked by the spline teeth of the stationary spline ring, means for operating the said pin engaging means to turn the tubular slide member to its first said angular position with its spline teeth clearing in the interdental spaces of the stationary spline ring, whereat the said tensile spring moves the tubular slide member breech-ward, the said muzzle closing means being moved to open position and the said pin approaching the said cam surface end of the elongated slot, the spline teeth of the tubular slide member being engaged by the spline teeth of the said stationary spline ring to prevent turning of the tubular slide member, the said spline teeth of the spline ring being moved with the gun barrel on recoil breech-Ward beyond the spline teeth of the tubular slide member, the said `pin of the tubular slide member riding on the said cam surface of the elongated slot whereby the tubular slide member is turned to the second said angular position. with the teeth of the spline ring in blocking alignment with the spline teeth of the tubular slide member, the teeth of the said spline ring engaging the teeth of the tubular slide member upon counter-recoil to move the tubular slide member muzzle-Ward, to bring the said muzzle closing means to closed position, the said pin of the tubular slide member being received in the said pin engaging means to maintain the tubular slide member in the second said angular position, with the tubular slide member blocked by the abutment of its spline teeth with the teeth of the spline ring against breech-ward movement of the tubular slide member and with the muzzle closing means maintained in closed condition, and means operated by the breech block mechanism of the gun for actuating the said pin engaging means.

'7. In a muzzle closing device for a gun, a gun barrel, a member reciprocal relative to the barrel. a muzzle closing assembly comprising a plurality of complementary foldable sections pivotally mounted on and adjacent the outer end of said member in position to fold over the gun muzzle in the forward position of said member, barrel engaging portions on said foldable sections adapted to engage the end of and slide along said barrel means included in the assembly so constructed and arranged to bias said sections and the barrel engaging portions toward each other and the gun barrel, and means for reciprocating said member and said foldable sections as an entirety relative to said barrel whereby upon rearward movement of said member and foldable sections relative to the barrel, the barrel engaging portions will be cammed over the end of and along the barrel to unfold said sections against said biasing means.

8. In a muzzle closing device for a gun having a xed part, in combination, a gun barrel, a member reciprocable on the barrel, a plurality of complementary spring-biased sections hinged to said member and having barrel engaging portions constructed and arranged to slide over the barrel with said member, said sections being shaped to fold over and close the gun muzzlelwhen the reciprocable member is in its forward position, spring means connecting said member to the fixed part of the gun and urging said member to a rearward position wherein said sections uncover theL muzzle, means for locking said member` in for- Ward position, and means for unlocking said member and surrendering it to said spring means connecting said member to said fixed part whereby said member is moved to bring the sections to muzzle uncovering position.

9. In a muzzle closing device for a gun whose barrel moves in recoil and counterrecoil, in combination, a gun barrel, a member reciprocably mounted on said barrel, a muzzle closing assembly comprising a plurality of complementary spring biased sections rockably mounted on said member and having barrel engaging portions, said sections being constructed and arranged to fold over and close the barrel muzzle when said member is in its forward normal position, springs norgmally urging said member rearwardly on the gun barrel to bring said section barrel engaging portions into engagement with the end of the barrel to unfold said sections upon the rearward movement of said reciprocable member, locking means carried by said member, locking mea-ns carried by the gun barrel cooperating with said member locking means to look said member in a forward po- 12 l sition, and means operable to disengage both locking means whereby said member can move said sections to a muzzle uncovering position.

l0. In a muzzle closing device for a gun Whose barrel moves in recoil and counterrecoil, in combination, a gun barrel, a stationary tubular memrber around the barrel and spaced therefrom and having an elongated slot having a cam surface therein, a tubular member surrounding the barrel and also spaced therefrom and reciprocable with respect to said stationary member, springs connecting the two members and urging the reciprocable member toward the stationary member, a muzzle closing assembly carried by the reciprocable member and comprising a plurality of complementary spring-biased sections constructed and arranged to fold together when the reciprocable member reaches its forward position to close the muzzle of the gun, a grooved tube secured to the inner Wall of the reciprocable member, a splined ring secured to the gun barrel and cooperating with said grooved tube to lock the reciprocable member against longitudinal movement with respect to the gun barrel and station-- ary member, a pin carried by the grooved tube and extending through the slot in said stationary member, a rockable lever on the stationary member normally engaging the pin to hold the grooved tube in locking relation to the splined ring, and means operable to rock the lever to partially rotate said grooved tube in one direction to bring the grooves therein into registry with the splines on said splined ring whereby said reciprocable member will be moved to the rear relatively to the stationary member and gun barrel by said connecting spring, said pin being constructed and arranged to engage the cam surface in said slot substantially at the end of the rearward movement of the reciprocable member to rotate said tube relative to said splined ring in a reverse direction to move said splines and grooves out of registry.

VICTOR F. LUCHT.

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