US2327922A - Cartridge guide for automatic machine guns - Google Patents

Description

Aug. 24, 1943- F. "r. MOORE arm.

CARTRIDGE GUIDE FOR AUTQMATIC MACHINE GUNS Filed May 31, 1938 2 Sheets-Sheet 1 Invent :2" Frederick T. Maura, Deceased ghfs adminfstrat 02" .Pfz'asnbcfitate ankandfiustfanpszzy W fly AIL-20mg Aug. 24, 19 3. F. T. MOORE ETAL CARTRIDGE GUIDE FOR AUTOMATIC MACHINE GUNS Filed lay 31, 1938 2 Sheets-Sheet 2 121129272302" Frederick TMaaraDscsassd .Eyhfs admjnfstratar Phasnfx 5 151: 5.552711 and Trus fl'w 1 WP fizz/1111 Patented Aug. 24, 1943 UNITED STATE N T OFFICE CARTRIDGE GUIDE FOR AUTOMATIC MACHINE GUNS Arms Manufacturing Company,

Hartford,

Conn., a corporation of Connecticut Application May 31, 1938, Serial No. 210,948

12 Claims.

While not necessarily so limited, the present invention is particularly applicable to a machine sun of the type disclosed in Patent No. 1,293,021 in the name of John M. Browning, in Patent No. 1,803,349 in the name of Christian Pfe'iifer, and in reissued Patent No. 19,159 in the names of Frederick T. Moore and Christian Pfeiifer.

In the machine gun of this type the main casing is provided with a transverse feed channel through which a cartridge belt is automatically fed, and there is provided a longitudinally movable extractor which engages the cartridges successively to withdraw them rearward from the belt so that they can thereafter be pushed forward into the chamber of the barrel. Each cartridge is provided near the rear with a circumferential groove forming an annular shoulder which is engaged by the extractor. In order that the'gun may operate without unintended inter ruption it is essential that the cartridges be accurately located in the feed channel; and it is obvious that if the grooved portion of any cartridge is too far forward to be properly engaged by the extractor, the cartridge will not be withdrawn from the belt and the operation of the gun will cease.

In order to properly position the cartridges for engagement by the extractor, it has been the usual prior practice to provide a cam or guide face at the front edge of the feed channel which face engaged the front nose of the bullet so as to properly locate the cartridge. This guide face was formed either on a separate bunter plate provided for that purpose, or was formed on the trunnion block itself. Such a guide face is effective for its intended purpose when the cartridges are accurate and uniform in their dimensions, but it has been found that an occasional failure may result from a cartridge which is shorter than normal. Such an inaccuracy in the cartridge may result from error in the original manufacture or may result from rough handling of such character as to cause the bullet to be forced into the case beyond its normal position. Reduc. tion in cartridge length is particularly likely to occur when the cartridge case cracks or splits adjacent the bullet, thus partly releasing the bullet so that it is readily forced into the case beyond its normal position. It also sometimes happens that the extractor itself in moving forward to engage the cartridge strikes a blow which drives the case forward with relation to the bullet thus shortening the cartridge and making it impossible for the extractor to withdraw it.

It has been herefore recognized that difliculties may arise on account of cartridge defects such as have been mentioned and it has hereto-i fore been proposed to provide in the feed channel an inclined cam or guide face which engages the front edges or faces of the successive cartridge cases to force them rearward in the event that they enter the feed channel in front of their normal path of movement.

When the gun is intended to be used with a disintegrating belt comprising metallic links, it has also heretofore been proposed to provide two separate guide faces adapted to engage respectively with the front faces of the cartridge cases and with the front faces of the belt links.

In accordance with the present invention there is provided a .combined cartridge guide and stop having certain novel features of construction and operation, this preferably constituting a separate unit in order that the invention may be more readily applicable to guns heretofore constructed and also applicable to newly constructed guns without substantially changing the already existing and standardized design and construction. The present invention relates in part to a separate unit for effecting the results that have been before stated, and also relates in part to means for connecting the unit with the gun.

Modern practice, particularly as to machine guns intended for airplane use, requires that the feed mechanism and associated parts be adjustable so that the direction of feeding may be readily reversed without the addition or substitution of any parts. In accordance with the present invention the guide unit is so constructed that it can be placed in either of two positions and used for its intended purpose with feeding taking place in one direction or in the other direction.

In addition to the main objects and purposes of the invention which have been set forth, the invention includes various other advantageous details and combinations of parts which will be more fully understood from the accompanying drawings and from the following specification.

In the drawings there are shown two different embodiments of the invention but the drawings are intended to be illustrative only and are not intended to define or limit the scope of the invention, the claims forming a part of the specification being relied upon for that purpose.

Of the drawings:

Fig. 1 is a fragmentary plan view of a machine gun embodying the invention, the top cover and parts carried thereby being omitted.

Fig, 2 is a fragmentary side view including the cover which is shown in raised position.

Fig. 3 is a fragmentary sectional view taken along the line 8-8 of Fig. 2.

Fig. 4 is an enlarged perspective view showing the guide unit to which the invention more particularly relates.

Fig. 5 is a perspective view on the same scale as Fig. 4 and showing a fragment of a cartridge belt.

Fig. 6 is a view similar to Fig. 3 but showing the guide unit in reversed position so as to be adapted for feeding in the opposite direction.

Fig. 7 is an enlarged perspective view showing a different guide unit which may be used as an alternative to the guide unit shown in Fig. 4.

Fig. 8 is a fragmentary view similar to Fig. 2 but including the alternative guide unit shown in Fig. '7.

Figs. 9 and 10 are views similar respectively to Figs. 3 and 6 but including the alternative u de unit shown in Fig. 7.

The machine gun so far as shown in Figs. 1, 2 and 3 will be briefly described, but for various details which are not here fully shown reference may be had to ,the prior patents which have already been mentioned.

The main or breach casing of the gun is shown at l this casing containing the breech mechanism and being rectangular in form. The casing includes two side plates 2, 2 and a tunnnion block 3 which is positioned between the side plates at the front. The casing is provided with an openable top cover 4 which is omitted in Fig. 1 but which is shown in raised position in Fig. 2. This cover is pivoted to the breech casing at 5.

Projecting from the casing at the front thereof is a barrel 6 surrounded by a jacket I, fragments of the barrel and jacket being shown in Fig. 2. Upon recoil the barrel is movable rearward to a limited extent and in so moving it operates the breech mechanism of the gun. The said breech mechanism includes a longitudinally movable breech bolt 8 which upon recoil moves rearward to a greater extent than does the barrel.

The breech casing of the gun is provided with a transverse feed channel 9, and brackets I and i l are secured to the side plates so as to provide the end portions of the channel. Associated with the feed channel is a suitable mecshanism for engaging a cartridge belt to feed it through the said channel. Although the invention is not necessarily so limited, it is particularly useful with a belt of the metallic link disintegrating type, and a short section of such a belt is shown in Figs. 1 and 2. The belt fragment includes two cartridges A and B and three links 0, D and E. Fig. is an enlarged perspective view of a portion of the belt section shown in Figs. 1 and 2, only one cartridge and two links being shown. The term belt" or cartridge belt as used herein used is to be understood as referring to the links and cartridges collectively.

The feed mechanism for the cartridge belt is only herein briefly described since the same is ancillary to the essence of the present invention. For a complete description of the same, attention is directed to Browning patent 1,293,021 dated February 4, 1919. In the accompanying drawings of the present application, the feed mechanism includes a feed slide I2 which is carried by the openable cover 4 and which is reciprocable transversely of the gun. The slide is reciprocated by means of a feed lever I3 pivoted to the cover at l3. This lever carries a depending stud (not shown) which extends into one of the cam grooves It and I 4 in the top face of the breech bolt 8. As the breech bolt reciprocates longitudinally, the feed lever I3 is caused to oscillate and this in turn effects transverse reciprocation 01' the feed I slide I2. A pawl I5 is carried by the feed slide and this pawl at each reciprocation engages a cartridge of the belt to move it into the central position occupied by the cartridge A shown in Fig. 1. A second pawl I8 is provided at the entrance end of the feed channel and pivotally mounted on a longitudinal retaining pin I! extending through apertures in the bracket III at the entrance end of the feed channel. The pawl It serves to engage successive cartridges to prevent any possible backward or retrograde movement of the belt. Stops I8 and I9 are provided for engaging the rear portion of the cartridge in the position A to limit the feeding movement thereof. These stops are held in place by a longitudinal retaining pin 20 similar to the pin I1 but extending through apertures in the bracket II at the other end of the feed channel.

Each cartridge is provided with an annular groove near the rear end which provides a shoulder adapted to be engaged by an extractor 2| movable with the breech bolt and pivoted thereto at 22. The extractor has a depending tooth 23 which is adapted to enter the groove in the cartridge and engage the said shoulder. The timing is such that the extractor engages the cartridge immediately upon its arrival at the position A, the breech bolt and extractor thereupe on moving rearward and withdrawing .the cartridge from the belt. Upon the return forward movement of the breech bolt the cartridge is pushed into the chamber of the barrel, and the extractor returns to the position shown in Fig. 2 for engagement with the next cartridge, which has in the meantime been fed to the position A. The withdrawal of the cartridge from the position A frees the forward link C which is ejected from the feed channel upon the next feeding movement of the belt.

Preferably the gun is so constructed that feeding can be efiected in either direction, this being possible without the addition or substitution of any parts of the gun. In reversing the direction of feeding, the feed slide I2 is reversed in position and the cam block or switch 24 is adjusted so that the cam groove 24 thereof will register with the cam groove I 4 in the breech bolt instead of with the cam groove I4, as shown. The stud on the lever I3 is entered in the cam groove Hi instead of in the cam groove I4, and this changes the timing of the reciprocation 01' the feed slide I2 so as to accommodate feeding in the opposite direction. It is also necessary to move the pawl l6 to the other end of the feed channel, mounting it on the pin 20 instead of the pin I I. The stops I8 and I9 are reversed in position, being mounted on the pin I'l instead of on the pin 20. The reversible feed mechanism is shown in greater detail and more fully described in the before mentioned reissued Patent No. 19,159.

As already explained it is essential that the cartridge be so positioned as to definitely assure engagement of the tooth 23 of the extractor with the shoulder formed by the groove in the cartridge. Obviously, if the cartridge were in front of the position shown in Fig. 2, the cartridge would not be properly engaged by the extractor and the extractor would fail to withdraw the cartridge and the gun would cease 'to function.

Heretofore reliance has commonly been placed on a guide face, such as that at 25, at the front of the feed channel for engaging the nose of the bullet to properly position the cartridge for engagement by the extractor, but this guide face sometimes fails to accomplish the desired result by reason of inaccurate positioning of the bullet with respect to the cartridge case. In accordance with one phase of the present invention, a means is provided which engages directly with portions of the cartridge belt other than the bullet, that is, preferably with the front edges or faces of the cartridge cases. The means provided for this purpose may be constructed as a fixed part of the gun; but it is preferred, particularly when there is a reversible feed mechanism, to construct the guiding means as a separate unit which can be detachably mounted and which can be moved to different positions in accordance with the reversal of feed.

The guide unit as shown in Figs. 1, 2, 3 and 4 comprises a main block 26 which is adapted to be positioned in the feed channel adjacent the exit end thereof and it also comprises at least one and preferably two plates 21 and 28 which have inclined rear faces 2! and 28 adapted to engage the front face of each cartridge case as it is fed through the feed channel and approaches the position A. The distance between the plates is approximately equal to the diameter of the bullet, and thus the guide faces 21 and 28 necessarily engage the front face of the cartridge case, this engagement being approximately at the top and bottom. From an inspection of Fig. 1

it will be apparent that if the cartridge enters the feed channel in front of its normal path of movement it will be forced rearward to its proper position by the inclined faces 21 and 28.

In addition to the plates 21 and 28 the guide unit preferably comprises at least one and preferably two plates 29 and 30. These plates 29 and 39 have rearward facing inclined faces 29* and 39 adapted to engage with the front faces of the successive links of the cartridge belt. From an inspection of Fig. 1 it will be apparent that, if any link enters the feed channel in front of its normal path of movement it will be forced rearward as it approaches the position D. Inasmuch as each link is in a definite relationship to the corresponding cartridge, the two sets of faces 21, 28 and 29 36 cooperate to force the cartridges rearward. In fact, the faces 29, 3|] would be effective for this purpose even if the faces 21, 28 were omitted.

Preferably the two sets of plates 21, 28 and 29, are structurally separatefrom the block 26 and are formed from resilient sheet metal. The plates may be connected to each other and to the block 26 by countersunk flush rivets, as shown. The plates 29 and 30 may be provided with upward and downward inclined extensions 29 and 30 which provide converging surfaces for guiding the cartridges into the belt channel.

The cooperation between the cam faces of the guide unit and the cartridge belt will be more readily apparent from an inspection of Figs. 4 and 5 which show the guide unit and the belt in perspective and on the same scale. It will be evident that the cam faces 21- and 28 will engage the front faces of the cartridge case approximately at a and b, and that the cam faces 29 and 30* will engage the front faces of the belt links approximately at c and d.

Preferably the block 26 not only serves to support the plates 21, 28, 29 and'30, but also serves as a stop for engaging both the bullet and the case of each cartridge so as to limit the transverse feeding movement thereof. For this purpose the block 26 is provided with a stop face 26 which is curved to fit or approximately fit the corresponding portion of the cartridge. Thus the stop at 26 cooperates with the stops at l8 and I9 to definitely position the cartridge and to prevent any possible transverse tilting thereof.

When the extractor 2| moves forward to engage a cartridge it necessarily strikes the cartridge so that the tooth 23 can ride over the rear edge of the cartridge and enter the annular notch therein. Ordinarily the blow struck by the extractor is not severe, but under some circumstances there is-a tendency for this blow to move the cartridge forward out of its normal position. The guide faces 21 and 28 tend to prevent any such forward movement but in order to present a still greater contact area for preventing forward movement, it is preferred to provide the stop with a ledge or shoulder having a rearward exposed face 26 This face 26 registers with the adjacent guide portions 21 and 28 and engages the front face of each cartridge case/ The guide unit, and preferably the block 26 thereof, is provided near its outer end with a depending apertured lug 26 which is adapted to project downward into a notch 3| in the floor of the feed channel adJacent the exit endthereof. This notch is traversed by the before mentioned pin 20 which pin extends through the aperture in the lug 26 and thus holds the guide unit in place. The plates 29 and 30 project beyond the inner end of the block, and preferably additional extensions 29 and 30 are formed on the plates, these projecting upward and downward. One of these extensions, that is 30, projects downward into a notch 32 which is similar to the notch 3| and is adjacent the entrance end of the feed channel. The extension 39 approximately fits the notch 32 so as to support the corresponding end of the guide unit and prevent forward or rearward movement thereof. A bar or rod'33 secured to the bottom of the cover 4 engages the top of the unit, and therefore when the cover is closed the unit is firmly held against movement in any direction.

When the guide unit is to be moved to permit feeding in the opposite direction, it is reversed so as to occupy the'position shown in Fig. 6. In this position the apertured lug 26 enters the notch 32 and is engaged by the pin I! and the plate extension 29 enters the notch 3|. The guide unit acts in exactly the same way for the reversed position and repetition of the description is unnecessary.

Figs. 7, 8, 9 and 10 show an alternative construction which is in many respects similar to the construction already shown and described. The cam or guide plates 21 and 28 are the same as already described and function in the same manner. The plates I29 and I30 correspond in a general way to the plates Hand 39, but the inclined guide faces 29 and '30 are omitted and the width is reduced so that the plates do not engage the links of the belt. Preferably the block I26 is correspondingly reduced in width, and it is provided with a. ledge or shoulder I26 corresponding in function to the ledge or shoulder 26 already described. The plates I29 and I30 serve chiefly to reinforce and support the plates 21 and 28 and they have no direct function in determining the path of movement of any part of the cartridge belt. The plates I29 and I30 do not have extensions such as 28, 29 and 30, 30.

with the extensions 29 and 80 omitted the guide unit as shown in Figs. '7, 8, 9 and would be less firmly supported at the entrance end of the feed channel and there would be a tendency for it to be deflected forward by reason of the pressure exerted by the cartridge belt. To avoid this the block I26 is provided with a pin I34 which projects forward so that its front edge engages the front wall of the feed channel. Thus the guide unit is firmly supported so as to resist any tendency for it to be deflected in the forward direction.

The alternative guide unit may be reversed in accordance with the direction of feeding in the same manner as the guide unit first described. Fig. 9 shows the unit positioned for one direction of feeding and Fig. 10 shows it positioned for the opposite direction of feeding.

What is claimed is:

1. In an automatic machine gun, the combination of a breech casing having a transverse feed channel therein, mechanism associated with the channel for feeding a cartridge belt there through, a longitudinally movable extractor adapted to engage successive cartridges within the channel and extract them rearward from the belt, and a cartridge guide within the channel comprising two resilient plates respectively above and below the path of cartridge movement, the said plates having two similar inclined faces engageable with the front face of each cartridge case approximately at the top and bottom thereof and serving to force the cartridge rearward in the event that it enters the channel in front of its normal path of movement and the said plates having at the entrance and of the channel extensions which are inclined respectively upward and downward to provide converging surfaces for guiding the cartridges into the channel.

2. The combination in an automatic machine gun, of a breech casing having a transverse feed channel therein, a notch being provided in the floor of the feed channel near the exit end thereof, a longitudinal retaining pin extending across the said notch, mechanism associated with the channel for feeding a cartridge belt therethrough, and a cartridge guide unit within the channel comprising a block formed at its inner end to constitute a cartridge stop and having near its outer end an apertured lug which projects into the aforesaid notch and is engaged by the said retaining pin, the said unit also comprising a plate structurally separate from the block but secured thereto and projecting beyond the inner end thereof which plate has an inclined face engageable with the front face of each cartridge case and serving to force the cartridge rearward in the event that it enters the channel in front of its normal path of movement.

3. The combination in an automatic machine gun, of a breech casing having a transverse feed channel therein, two notches being provided in the floor of the feed channel near the respective ends thereof, a longitudinal retaining pin extending across the notch at the exit end of the channel, mechanism associated with the channel for feeding a cartridge belt therethrough, and a cartridge guide unit within the channel having a face which is engageable with successive portions of the cartridge belt as the belt is fed and which is inclined so as to force the belt rearward in the event that it enters the channel in front of its normal path of movement, the said unit having an apertured lug near one end which proiects into and fits the notch' at the exit end of the channel and is engaged bythe said retaining pin for holding the unit in place and the said unit also having an extension at the other end which projects into and fits the notch at the entrance end of the channel.

4. A cartridge guide unit adapted to be mounted in the feed channel of an automatic machine gun and comprising a block formed at its inner end to constitute a cartridge stop and having near its outer end an apertured lug adapted to project into a notch in the floor of the channel and to be engaged by a retaining pin, the said unit also comprising a plate structurally separate from the block but secured thereto and projecting beyond the inner end thereof which plate has an inclined guide face engageable with the front face of a cartridge case as the cartridge is fed through the channel and serving to force the cartridge rearward in the event that it enters the channel in front of its normal path of movement.

5. A cartridge guide unit adapted to be mounted in the feed channel of an automatic machine gun, the said unit comprising in combination a block having an apertured lug adapted to project into a notch in the floor of the channel adjacent the exit end thereof and to be engaged by a retaining pin, and two resilient plates structurally separate from the block and carried thereby at the top and bottom thereof, the said plates having two similar inclined faces engageable with the front face of each cartridge case approximately at the top and bottom thereof and serving to force the cartridge rearward in the event that it enters the channel in front of its normal path of movement and the said plates having extensions which are inclined respectively upward and downward to provide converging surfaces for guiding the cartridges into the channel.

6. A cartridge guide unit adapted to be mounted in the feed channel of an automatic machine gun, the said unit comprising in combination a block having an apertured lug adapted to project into a notch in the floor of the channel adjacent the exit end thereof and tobe engaged by a retaining pin, and two resilient plates structurally separate from the block and carried thereby at the top and bottom thereof, the said plates having two similar inclined faces engageable with the front face of each cartridge case approximately at the top and bottom thereof and serv ing to force the cartridge rearward in the event that it enters the channel in front of its normal path of movement and the said plates having extensions which are inclined respectively upward and downward to provide converging surfaces for guiding the cartridges into the channel and one of the said plates having an additional extension which is adapted to project into and fit a notch adjacent the entrance end of the channel.

'7. An automatic machine gun comprising in combination, a breech casing having a transverse feed channel therein, mechanism associated with the channel for feeding therethrough a cartridge belt of the metallic link disintegrating type, a longitudinally movable extractor adapted to engage successive cartridges wlthin the channel and extract them rearward from the corresponding links, and a guide unit within the channel comprising a block and also comprising two pairs of resilient plates structurally separate from the block and carried thereby at the top and bottom thereof, two plates of the said pairs having two similar inclined faces engageable with the front face of each cartridge case approximately at the top and bottom thereof and serving to force the cartridge rearward in the event that it enters the channel in front of its normal path of movement and the other two plates of the said pairs having two similar inclined faces engageable with the front face of each belt link approximately at the top and bottom thereof and serving to force the link rearward in the event that it enters the channel in front of its normal path of movement.

8. In an automatic machine gun, the combination of a breech casing having a transverse feed channel therein, mechanism associated with the channel for feeding a cartridge belt therethrough which mechanism is adjustable for feeding in either direction, a longitudinally movable extractor adapted to engage successive cartridges within the channel and extract them rearward from the belt, a cartridge guide adapted to be tom of the channel and engageable with the front face of each cartridge case approximately at the top and bottom thereof in each of the two positions of the guide and serving to force the cartridge rearward in the event that it enters the channel in front of its normal path of movement, and means for holding the guide in place in the channel in either of its said positions.

9. In an automatic machine gun, the combination of a breech casing having a transverse feed channel therein, mechanism associated with the channel for feeding a cartridge belt therethrough which mechanism is adjustable for feeding in either direction, a longitudinally movable extractor adapted to engage successive cartridges within the channel and extract them rearward from the belt, a cartridge guide unit adapted to be located in either of two positions within the channel according to the direction of feeding, two similarly inclined faces on said guide unit disposable respectively adjacent the top and bottom of the channel in either of said positions of the unit in the channel and engageable with successive portions of the belt to force the belt rearward in the event that it enters the channel in front of its normal path of movement, a face on said guide adapted to engage successive cartridges and limit the movement thereof in feeding direction, and means for holding the guide in place in the channel in either of its said positions.

10. The combination in an automatic machine gun of a breech casing having a transverse feed channel therein, mechanism associated with the channel for feeding a cartridge belt therethrough which mechanism is adjustable for feeding in either direction, a longitudinally movable extractor adapted to engage successive cartridges within the channel and extract them rearward from the belt, a cartridge guide adapted to be located in either of two relatively reversed positions within the'channel according to the direc tion of feeding, the said guide comprising two spaced plates having similar inclined faces which in each of the said positions are engageable with the front face of each cartridge case approximately at the top and bottom thereof and serve to force the cartridge rearward in the event that it enters the channel in front of its normal path of movement and the said plates having extensions which are inclined respectively upward and downward to provide converging surfaces for guiding the cartridges into the channel, and means for holding the guide in place in the channel in either of its said positions.

11. The combination in an automatic machine gun of a breech casing having a transverse feed channel therein, two similar notches being provided in the floor of the channel near the respective ends thereof, two longitudinal retaining pins extending across the respective notches, mechanism associated with the channel for feeding a cartridge belt therethrough which mechanism is adjustable for feeding in either direction, a longitudinally movable extractor adapted to engage successive cartridges within the channel and extract them rearward from the belt, and a cartridge guide adapted to be located in either of two relatively reversed positions within the channel according to the direction of feeding, the said guide comprising two apertured lugs one or the other-of which according to the position of the guide projects into one or the other of the notches and is enagged by the corresponding retaining pin and also comprising two spaced plates having similar inclined faces which in each of the said positions are engageable with the front face of each cartridge case approximately at the top and bottom thereof and serve to force the cartridge rearward in the event that. it enters the channel in front of its normal path of movement.

12. A guide unit adapted to be mounted in the feed channel of an automatic machine gun in either of two relatively reversed positions, the

said unit being provided with two apertured lugs PHOENIX STATE BANK AND TRUST COMPANY, Administrator of the Estate of Frederick T.

Moore, Deceased,

By RAY L. MAKIN,

Associate Tmst Ojficer.

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