Weapon system retention device

An apparatus for retaining an object in a gun tube of a weapon system, the gun tube having a longitudinal axis, a chamber and a breech ring with an opening therein, the apparatus including a plunger that reciprocates in the opening in the breech ring and the chamber; a housing fixed in the opening in the breech ring, the housing holding the plunger; and means for reciprocating the plunger in the opening in the breech ring and the chamber. The object to be retained is propellant. The reciprocating means is automatically operated via electrical and/or mechanical connections to the weapon system.

BACKGROUND OF THE INVENTION

The invention relates in general to weapon systems and in particular to a retention device for positioning propellant and/or ammunition in guns.

The problem of how to hold munitions in an open cannon chamber has existed for as long as cannons have been used. A common method is to de-elevate the cannon to a horizontal position between firings. This method drastically reduces the number of rounds fired per minute because of the time needed to reposition the cannon for firing. Another method used to hold propellant in an elevated chamber is the Swiss notch. The Swiss notch is basically a notch cut into the chamber of the cannon at the six o'clock position. The notch is designed so that propellant bags or charge modules will catch on the notch if they begin to fall out of the chamber due to gravity. The Swiss notch is only somewhat effective because it is totally dependent on the drop angle, weight, and profile of the propellant bag or module to fall uncontrolled into the notch. At higher angles, the propellant bag or module may not fall into the notch. In addition, experience has shown that the Swiss notch is not a foolproof method to keep the propellant bag or charge modules from falling out of the chamber at any elevated angle. Further, the combustion debris may fill the notch and render it useless.

In a breech-loaded cannon, it is most efficient to load propellant bags or charge modules using a device such as an automatic loader. Typically, the propellant bags or modules are loaded with the cannon muzzle at an elevated angle. However, upon withdrawal of the auto-loader ram, the propellant can fall out of the chamber due to the elevated muzzle.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a device to hold propellant inside a firing chamber until the breech is closed.

It is another object of the invention to provide a device to hold propellant inside a firing chamber without having to lower the muzzle, load the cannon and then reposition the muzzle.

It is a further object of the invention to provide a device to hold propellant inside a firing chamber wherein the device operates automatically.

One aspect of the invention is an apparatus for retaining an object in a gun tube of a weapon system, the gun tube having a longitudinal axis, a chamber and a breech ring with an opening therein, the apparatus comprising a plunger that reciprocates in the opening in the breech ring and the chamber; a housing fixed in the opening in the breech ring, the housing holding the plunger; and means for reciprocating the plunger in the opening in the breech ring and the chamber.

In one embodiment, the weapon system includes a non-recoil surface and the means for reciprocating the plunger includes a compression spring disposed around the plunger and a solenoid fixed to the non-recoil surface such that, when activated, the solenoid is operable to move the plunger into the chamber and, when deactivated, the compression spring moves the plunger out of the chamber.

In a second embodiment, the weapon system includes a breech crankshaft and the means for reciprocating the plunger includes a drive gear attached to the breech crankshaft; a fixed shaft having a driven gear mounted thereon that meshes with the drive gear; a cam mounted on the fixed shaft and including a cam path; and a cam follower fixed to the plunger and operable to follow the cam path of the cam.

In a third embodiment, the weapon system includes a breech crankshaft and the means for reciprocating the plunger includes a cam mounted on the breech crankshaft and including a cam path; a cam lever having one end rotatably attached to the housing and another end with an opening formed therein; a first cam follower fixed to the plunger and disposed in the opening in the cam lever; and a second cam follower mounted on the cam lever and operable to follow the cam path of the cam.

Another aspect of the invention is a method of retaining an object in a gun tube of a weapon system, the gun tube having a longitudinal axis, a chamber and a breech ring with an opening therein, the method comprising placing the object in the gun tube; and moving a plunger through the opening in the breech ring and into the chamber such that a portion of the plunger contacts a rear surface of the object.

The invention will be better understood, and further objects, features, and advantages thereof will become more apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention holds propellant bags or propellant modules inside the firing chamber of a gun until the breech is closed. The cannon is loaded at an elevated muzzle angle without having to lower the muzzle, load the cannon, and reposition the muzzle. Because some loading steps are eliminated, the invention is faster and safer than known methods. A paddle-like retaining device is introduced at the firing chamber entrance to hold the propellant in place. The retaining device may be mechanically, electrically and/or hydraulically inserted into the firing chamber.

In some embodiments, the retaining device is activated during the mechanical action of opening and closing the breech by using an electrically operated solenoid, hydraulic actuator or cam action. During firing, the retaining device is in the retracted position away from the chamber opening. After firing, the breech is opened and the projectile and propellant modules are loaded into the chamber for the next round. When the propellant modules have been placed into the firing chamber, the load ram is extracted and the retaining device is actuated. The retaining device may extend through a port in the breech ring and thence into the chamber access area to hold the propellant in place. The retaining device may be actuated in various ways.

FIGS. 1A and 1Bare sectional, schematic views of one embodiment of the invention in a deactivated and an activated mode, respectively. InFIGS. 1A and 1B, the view is from the breech end of the gun tube14looking forward. Apparatus10functions to retain an object12in the chamber19of a gun tube14of a weapon system16. The gun tube14has a longitudinal axis X and a breech ring18with an opening20therein. The apparatus10includes a plunger22that reciprocates in the breech ring18and the chamber19, and a housing24fixed in the opening20in the breech ring18. Housing24holds the plunger22. Apparatus10further includes a means for reciprocating the plunger22in the breech ring18.

InFIGS. 1A and 1B, the object12to be retained or positioned in the gun tube14is typically propellant, such as a bag or charge module. To effectively retain the object12in the tube14against the force of gravity, the end of the plunger22that contacts the object12may include an increased area portion28, as shown inFIG. 3. The increased area portion28contacts the rear end of the object12and prevents the object12from sliding rearward to the breech of the gun tube14.

The weapon system16includes a non-recoil surface30. In the embodiment ofFIGS. 1-2, the means for reciprocating the plunger22includes a compression spring32disposed around the plunger22and a solenoid34fixed to the non-recoil surface30. When activated, as inFIG. 1B, the solenoid34is operable to move the plunger22into the gun chamber19. When deactivated, as inFIG. 1A, the compression spring32moves the plunger22out of the gun chamber19. The weapon system16includes a fire control system36shown schematically inFIGS. 1A and 1Bas a box. The fire control system36is connected to the solenoid34via wire35, for activating and deactivating the solenoid34.

The solenoid34is actuated after the propellant is loaded into the gun tube14, causing the plunger22to extend into the breech chamber19behind the propellant, thereby holding the propellant12in place. Just prior to full closure of the breech, the solenoid34is deactivated and the plunger22is retracted. Plunger22remains retracted until the weapon system16has fired, the breech is reopened and a new charge is loaded into the gun tube. As best seen inFIG. 1B, a vertical plane V through tube14intersects a longitudinal axis A of plunger22forming an angle alpha. In one embodiment, it is preferred that alpha is about thirty-eight degrees. Of course, other angles may be used.

FIGS. 2A and 2Bare exploded and assembled perspective views, respectively, of the apparatus10ofFIGS. 1A and 1B. InFIG. 2A, the view is from the front of the gun tube looking rearward toward the breech. InFIG. 2B, the view is an angled view from the front looking rearward.FIGS. 2A and 2Bdo not show the solenoid34, the non-recoil surface30or the fire control system36.

As best seen inFIGS. 2A and 2B, apparatus10includes an indicator tab38inserted in a hole39in plunger22. Indicator tab38moves up and down in slot37of housing24with plunger22. Thus, indicator tab38may be used as a check on the position of plunger22. For example, indicator tab38may comprise a magnetic material and a magnetic sensor may be mounted adjacent housing24to sense the position of indicator tab38. The magnetic sensor may be connected to the fire control system36(FIGS. 1A and 1B) such that an incorrect position of plunger22stops the operation of weapon system16.

FIGS. 4A and 4Bare sectional, schematic views of a second embodiment of the invention in a deactivated and an activated mode, respectively. InFIGS. 4A and 4B, the view is from the breech end of the gun tube looking forward. The apparatus40functions to retain an object12in the chamber19of a gun tube14of a weapon system16. The gun tube14has a longitudinal axis X and a breech ring18with an opening20therein. The apparatus40includes a plunger42that reciprocates in the breech ring18and chamber19, and a housing44fixed in the opening20in the breech ring18. Housing44holds the plunger42. Apparatus40further includes a means for reciprocating the plunger42in the gun breech ring18and chamber19.

Weapon system16includes a breech crankshaft (not shown) that fits through lug46. The means for reciprocating the plunger42includes a drive gear48attached to the breech crankshaft; a driven gear52that meshes with and is driven by the drive gear48, the driven gear52being rotatably mounted on a fixed shaft50; a cam54mounted on the fixed shaft50and including a cam path56(FIG. 5); and a cam follower58fixed to the plunger42and operable to follow the cam path56(FIG. 5) of the cam54. As shown inFIG. 5, the cam54comprises a generally conical shape and includes the cam path56on an external surface thereof.

FIG. 5is an exploded view of the second embodiment, viewed from the front of the gun tube looking rearward. Both the drive gear48and the fixed shaft50have been shifted to the right inFIG. 5. One end of the driven gear52includes a flange60that mates with a recess74(FIG. 8C) in the interior of cam54to drive the cam54. As shown inFIG. 4B, an angle beta between a longitudinal axis M of the plunger42and an axis of rotation N of the fixed shaft50is an acute angle. Preferably, the angle beta is about 45 degrees. Details of apparatus40are further seen in the perspective views ofFIGS. 6A-6C.

FIG. 6Ashows the housing44and plunger42lifted away from breech ring18to show the opening20in breech ring18. The drive gear48is shown removed from breech lug46. The breech crankshaft (not shown) engages drive gear48on the opposite side of breech lug46. The driven gear52, fixed shaft50and cam54are not shown inFIG. 6A. FIG.6B shows the driven gear52and the fixed shaft50. Drive gear48(FIG. 6A) drives driven gear52thereby rotating the flange60. Flange60engages the interior74(FIG. 8C) of cam54and drives cam54. Drive gear48(FIG. 6A) is supported in opening62in breech lug46and fixed shaft50is supported in a second opening64in lug46.FIG. 6Cshows the cam54assembled to the fixed shaft50(located inside of cam54).

FIG. 7is an exploded view of housing44and plunger42. Plunger42is formed in two parts with ribs or teeth70that mesh together in housing44. Plate66secures plunger42in housing44. The lower end of plunger42includes the portion68that contacts the object in the chamber19. The portion68is generally widened to increase the area of contact and may be bent as needed.

FIGS. 9A and 9Bare sectional views of a third embodiment of the invention in a deactivated and an activated mode, respectively. InFIGS. 9A and 9B, the view is from the rear of the gun looking forward.FIGS. 10A and 10Bare exploded, perspective views of the third embodiment. The third embodiment is an apparatus80that functions to retain an object12in a chamber19of a gun tube14of a weapon system16. The gun tube14has a longitudinal axis X and a breech ring18with an opening20therein. The apparatus80includes a plunger82that reciprocates in the breech ring18and the chamber19, and a housing84fixed in the opening20in the breech ring18. Housing84holds the plunger82. Apparatus80further includes a means for reciprocating the plunger82in the breech ring18.

Weapon system16includes a breech crankshaft86that fits through breech ring lugs46. The means for reciprocating the plunger82includes a cam88mounted on the breech crankshaft86and rotated by the carrier (not shown). Cam88is generally disc shaped and includes a cam path90(FIG. 10B) formed on one side. A cam lever92(FIG. 10A) has one end rotatably attached to the housing84using cam lever shaft98. Torsion spring100provides a biasing force to the cam lever92.

The other end of cam lever92includes an opening130therein. Cam follower96is fixed to the plunger82(FIGS. 9A and 9B) with cam shaft120. Cam follower96rides in opening130in cam lever92and moves the plunger82up and down as the cam lever92rotates about cam lever shaft98. Cam follower94is connected to the cam lever92with cam shaft118and rides in cam path90(FIG. 10B). As shown inFIG. 9A, an angle delta between the longitudinal axis S of the plunger82and an axis of rotation T of the breech crankshaft86is about ninety degrees.

Further details of the assembly of apparatus80are seen inFIGS. 10A and 10B. Plunger82(FIG. 9A) comprises a split rod with an upper portion102and a lower portion104. Housing cover plate106confines plunger82(FIG. 9A) in housing84. A steel plug108functions as a target for proximity sensors (not shown) that are placed in the top and bottom of the housing cover plate106. As the upper portion102of the plunger82moves up and down, the proximity sensors (not shown) in the housing cover plate106sense the presence or absence of the steel plug108and thereby provide an indication of the location of plunger82, that is, activated (FIG. 9B) or deactivated (FIG. 9A). Cam lever shaft98is provided with a bushing110and spring pin112. A housing plate washer114and bolts116are used to attach housing cover plate106to housing84. Cam followers94,96ride on cam follower shafts118,120.