Propellant retention device

Information

  • Patent Grant
  • 6513415
  • Patent Number
    6,513,415
  • Date Filed
    Thursday, March 22, 2001
    23 years ago
  • Date Issued
    Tuesday, February 4, 2003
    21 years ago
Abstract
A dual action retention pawl for securing ammunition in a breech loading gun having a bore along a longitudinal axis of a barrel of the gun and a breech opening with a moveable breech block at a rear of the bore. The dual action retention pawl includes a base, a pawl arm, and an activation arm operably attached to the base. The pawl arm pivots to a retracted position in response to ammunition engaging the activation arm when the ammunition is loaded into the breech opening and returns to a retention position once the ammunition is loaded to retain the ammunition within the barrel of the gun. The pawl arm pivots to the retracted position in response to the breech block engaging the activation arm when the breech block is moved to close the breech opening.
Description




FIELD OF THE INVENTION




The present invention relates generally to a propellant retention device. More particularly, the present invention relates to a retention pawl for retaining modular propellant increments in a gun barrel during a loading process.




BACKGROUND OF THE INVENTION




Traditionally, most larger caliber guns, such as guns having a caliber of greater than 105 millimeters, are loaded with ammunition from a breech end of the gun barrel. This process typically involves removing a breech block from the breech end of the gun barrel to provide access to the breech end of the gun barrel. Next, a projectile is inserted into the gun barrel. Propellant is then placed into the gun barrel and the breech block is positioned over the breech end of the gun barrel.




To enhance the ease of loading propellant into the gun barrel, the propellant is usually packaged in modular increments. By changing the number of increments loaded, the amount of force imparted to the projectile during the firing process can be varied.




In most breech loading guns that separately load propellant, a lower surface of the gun barrel has a depression that forms a lip in the gun barrel. This lip is often referred to as a Swiss notch. As propellant increments are inserted into the gun barrel, the propellant increments are prevented from sliding backwardly out of the gun barrel by the lip. Once all of the propellant increments are loaded into the gun barrel, the breech block is moved into position behind the breech end of the gun barrel and thereby prepare the gun for firing.




In order for the lip to be effective at retaining the propellant increments in the gun barrel, the gun barrel must be rotated to a substantially horizontal orientation before initiating the loading process. Such a procedure is particularly suited for manual loading processes because it is difficult for a person performing the loading process to insert the projectile and the propellant into the gun barrel when the gun barrel is oriented at an angle that substantially deviates from horizontal.




It can be appreciated that the time needed to perform the loading operation is significantly increased by lowering the gun barrel from the desired firing orientation to a horizontal loading orientation. Additionally, once the gun is reloaded it must be raised from the loading orientation to the desired firing orientation before firing the gun.




SUMMARY OF THE INVENTION




The present invention relates to a dual action retention pawl for securing ammunition components in a breech loading gun. The gun has a barrel with a bore along a longitudinal axis of the barrel. The gun also has a breech opening with a moveable breech block at a rear of the bore. The dual action retention pawl includes a base, a pawl arm and an activation arm.




The base is operably attached to the barrel of the gun. The pawl arm and an activation arm are operably attached to the base such that the pawl arm pivots to a retracted position in response to an ammunition component engaging the activation arm when the ammunition component is loaded into the breech opening and returns to a retention position once the ammunition component is loaded to retain the ammunition component within the barrel of the gun. The pawl arm pivots to the retracted position in response to the breech block engaging the activation arm when the breech block is moved to close the breech opening.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side view of a propellant retention device of the present invention attached to a gun barrel.





FIG. 2

is a front view of the propellant retention device attached to the gun barrel.





FIG. 3

is a perspective view of the propellant retention device in a retention configuration.





FIG. 4

is a side view of the propellant retention device in the retention position.





FIG. 5

is a side view of the propellant retention device in a fully retracted position.





FIG. 6

is a side view of the propellant retention device in a partially retracted position.











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS




The present invention is directed to a propellant retention device, as most clearly illustrated at


10


in

FIGS. 1 and 2

. The propellant retention device


10


retains ammunition components


12


as they are loaded into a gun barrel


14


. Ammunition components


12


can include one or more projectile and one or more modular propellant packets or increments.




The propellant retention device


10


prevents ammunition components


12


from falling out of a breech end


16


of the gun barrel


14


during manual or automated loading processes. The propellant retention device


10


of the present invention thereby enhances the ease and safety of the loading process. The propellant retention device


10


also enhances the ability to reload the gun at a variety of orientations including orientations that are near vertical.




The propellant retention device


10


is particularly suited for use with larger size guns where the propellant is loaded separately from the projectile. The gun barrel


14


preferably has a caliber of greater than 50 millimeters and, more preferably, is about 155 millimeters.




The propellant retention device


10


generally includes a base


20


and an arm assembly


22


. The base


20


is mounted to an outer surface


24


of the gun barrel


14


proximate to the breech end


16


of the gun barrel


14


.




The arm assembly


22


preferably has an over center configuration. When in a retention position, the arm assembly


22


extends preferably about 30 millimeters into the gun barrel


14


. When in the retracted position, the arm assembly


22


does not intrude into the gun barrel


14


to thereby permit the breech end


16


of the gun barrel


14


to be sealed for firing.




The arm assembly


22


generally includes activation arm


30


and a retention pawl


32


, as most clearly illustrated in

FIGS. 3 and 4

. The retention pawl


32


is operably attached to the activation arm


30


such that movement of the activation arm


30


between the retention position, as illustrated in

FIG. 4

, and a retracted position, as illustrated in

FIG. 5

, causes the retention pawl


32


to move between the retention position, as illustrated in

FIG. 4

, and a retracted position, as illustrated in FIG.


5


.




The activation arm


30


preferably has a generally U-shaped configuration, as most clearly illustrated in

FIGS. 3 and 4

. A first leg


34


of the activation arm


30


is used for moving the propellant retention device


10


between the retention and retracted positions. A second leg


36


operably connects the activation arm


30


to the retention pawl


32


.




The activation arm


30


is pivotally attached to the base


20


intermediate the first leg


34


and the second leg


36


for rotation about a first mounting shaft


40


. A biasing mechanism


42


, such as a spring, urges the activation arm


30


to the retention position.




Opposite the first mounting shaft


40


, the first leg


34


preferably includes a roller


42


rotatably mounted thereto. The roller


42


has a diameter that is slightly greater than a thickness of the first leg


34


so that the roller


42


extends above the side and end surfaces of the first leg


34


. The roller


42


enhances the ability to slide the ammunition components


12


past the activation arm


30


.




To further enhance the ability to move the ammunition components


12


past the activation arm


30


, the activation arm


30


preferably includes a lower region


46


and an upper region


44


that are oriented at an angle with respect to each other. The angle α between the lower region


46


and the upper region


44


is less than 180°, preferably between 120° and 170°, and more preferably about 140°.




The retention pawl


32


is preferably operatively attached to the second leg


36


of the activation arm


30


using a first connecting member


60


. A first end


62


of the first connecting member


60


is pivotally attached to the second leg


36


using a second mounting shaft


64


. A second end


66


of the first connecting member


60


is pivotally attached to the retention pawl


32


with a third mounting shaft


68


. The second leg


36


preferably includes two leg sections that are oriented on either side of the first connecting member


60


.




The retention pawl


32


is preferably operatively attached to the base


20


using a second connecting member


70


. A first end


72


of the second connecting member


70


is pivotally attached to the base using a fourth mounting shaft


74


. A second end


76


of the second connecting member


70


is pivotally attached to the retention pawl


32


with the third mounting shaft


68


.




The second connecting member


70


preferably includes two sections that are attached on either side of the retention pawl


32


. The two sections are preferably shaped substantially identical to each other. Using the two section configuration enhances the lateral stability of the retention pawl


32


.




The third mounting shaft


68


also pivotally attaches the first connecting member


60


to the second connecting member


70


. A biasing mechanism


80


, such as a spring, urges the retention pawl


32


to pivot away from the second connecting member


70


towards the retention position.




The retention pawl


32


preferably includes an elongated main portion


82


and an end portion


84


. The end portion


84


is oriented substantially perpendicular to the main portion


82


and thereby provides a relatively large surface that retains the ammunition components


12


in the gun barrel


14


.




The propellant retention mechanism


10


also preferably includes a sensor mechanism


90


that senses whether the propellant retention mechanism


10


is in the retention position. The sensor mechanism


90


thereby provides an additional level of safety during the propellant loading process. For example, if the sensor mechanism


90


senses that the propellant retention mechanism


10


does not return to the retention position after the insertion of the ammunition components


12


into the gun barrel


14


, the sensor mechanism


90


notifies the operator of the error and halts the automatic loading process.




The sensor mechanism


90


preferably includes a cam


92


attached to an end of the first mounting shaft


40


. The cam


92


includes at least one region that has a greater height. The sensor mechanism


90


also includes a sensor


94


that is attached to the base


20


. Certain angular orientations of the cam


92


engage the sensor


94


and thereby indicate that the propellant retention device


10


is in an appropriate angular orientation. A person of ordinary skill in the art will appreciate that it is possible to sense the position of the propellant retention device


10


using a variety of techniques using the concepts of the present invention.




The components of the propellant retention device


10


are preferably fabricated from high strength metallic materials such as steel. The thickness of the individual components is selected such that the components do not exhibit deformation over repeated uses of the propellant retention device


10


. A person of ordinary skill in the art will appreciate that care must be taken selecting components with sufficient structural integrity to withstand deformation as failure of the propellant retention device


10


can lead to damage of the ammunition components


12


thereby creating a significant risk of injury to people or equipment in close proximity thereto.




In operation, the propellant retention device


10


is initially in the retention position, as illustrated in

FIGS. 1 and 4

. During the process of inserting the ammunition components


12


, the ammunition component


12


slides along a central axis


118


of the gun barrel


14


, as indicated by arrow


120


in

FIG. 1

, and contacts the upper portion


44


of the activation arm


30


. The ammunition component


12


urges the activation arm


30


to pivot towards the base


20


, as indicated by arrow


100


. As noted above, the term ammunition component


12


encompasses both the projectile and the propellant increments.




Pivoting of the activation arm


30


towards the base


20


causes the first connecting arm


60


to pivot the second connecting member


70


towards the activation arm


30


, as indicated by arrow


102


. Continued pivoting of the activation arm


30


causes the arm assembly


22


to be further retracted into the base


20


.




The activation arm


30


then contacts the retention pawl


32


and causes the retention pawl


32


to be further pivoted into the base


20


, as illustrated in FIG.


6


. Pivoting continues until the ammunition component


12


may slide past the activation arm


30


and into the gun barrel


14


.




Once the ammunition component


12


moves past the end of the activation arm


30


, the force of the spring


42


causes the activation arm


30


to pivot back to the retention position. Pivoting of the activation arm


30


causes the second connecting member


70


to pivot with respect to the base


20


. This process continues until the activation arm


30


is in the retention position. The spring


80


biases the retention pawl


32


away from the second connecting member


70


. The retention pawl


32


is thereby positioned in the breech end


16


, as illustrated in FIG.


1


. of the gun barrel


14


to prevent the propellant packet from falling out of the gun barrel


14


.




During this process, the projectile and from 1 to 6 propellant increments


12


are loaded into the gun barrel


14


. The structure of the propellant retention device


10


of the present invention is particularly suited for automatic propellant loading operations to thereby increase the safety associated with this process.




After all of the ammunition components


12


have been inserted into the gun barrel


14


, it is necessary for a breech block


110


to be moved into position over the breech end


16


of the gun barrel


14


prior to firing. The breech block


110


is preferably slid along an axis that is substantially perpendicular to the central axis


118


of the gun barrel


14


, as indicated by arrow


122


in

FIG. 1

, and contacts the lower portion


46


of the activation arm


30


and urges the activation arm


30


to pivot towards the base


20


, as indicated by arrow


100


in FIG.


4


.




Pivoting of the activation arm


30


towards the base


20


causes the first connecting arm


60


to pivot the second connecting member


70


towards the activation arm


30


as indicated by arrow


102


. Continued pivoting of the activation arm


30


causes the components of the propellant retention device


10


to be further retracted into the base


20


.




The activation arm


30


then contacts the retention pawl


32


and causes the retention pawl


32


to be further pivoted into the base


20


, as illustrated in FIG.


6


. Pivoting continues until the activation arm


30


and the retention pawl


32


are located substantially within the base


20


, as illustrated in FIG.


5


. At this point, the breech block


110


is fully closed and ready to fire.




After the gun is fired and it is necessary to reload the gun, the breech block


110


is slid away from the breech end


16


of the gun barrel


14


. As the breech block


110


moves away from the propellant retention device


10


, the force of the spring


42


causes the activation arm


30


to pivot towards the retention position. Pivoting of the activation arm


30


causes the second connecting member


70


to pivot with respect to the base


20


. This process continues until the activation arm


30


is in the retention position. The spring


80


biases the retention pawl


32


away from the second connecting member


70


. The retention pawl


32


is thereby positioned in the breech end


16


, as illustrated in FIG.


1


.




It is contemplated that features disclosed in this application, as well as those described in the above applications incorporated by reference, can be mixed and matched to suit particular circumstances. Various other modifications and changes will be apparent to those of ordinary skill.



Claims
  • 1. A dual action retention pawl for securing ammunition components in a breech loading gun having a bore along a longitudinal axis of a barrel of the gun and a breech opening with a moveable breech block at a rear of the bore, the dual action retention pawl comprising:a base operably attached to the barrel of the gun; and a pawl arm and an activation arm operably attached to the base such that the pawl arm pivots to a retracted position in response to an ammunition component engaging the activation arm when the ammunition component is loaded into the breech opening and returns to a retention position once the ammunition component is loaded to retain the ammunition component within the barrel of the gun, and the pawl arm pivots to the retracted position in response to the breech block engaging the activation arm when the breech block is moved to close the breech opening.
  • 2. The dual action retention pawl of claim 1, wherein the retention pawl at least partially nests in the activation arm when in the retracted position.
  • 3. The dual action retention pawl of claim 1, further comprising a first biasing mechanism that biases the activation arm to the retention position.
  • 4. The dual action retention pawl of claim 1, wherein the activation arm has a U-shaped configuration with a first leg and a second leg, and wherein the activation arm is attached to the base intermediate the first leg and the second leg.
  • 5. The dual action retention pawl of claim 1. and further comprising:a first connecting member operably attaching the activation arm to the retention pawl; and a second connecting member operably attaching the retention pawl to the base.
  • 6. The dual action retention pawl of claim 5, and further comprising a second biasing mechanism that biases the retention pawl to the retention position.
  • 7. The dual action retention pawl of claim 1, and further comprising a sensor mechanism that senses when the activation arm is in the retention position.
  • 8. The dual action retention pawl of claim 7, wherein the sensor mechanism includes a cam operably attached to the activation arm.
  • 9. A breech loading gun comprising:a barrel having a bore aligned along a longitudinal axis thereof, wherein the barrel has a breech opening; a breech block for selectively covering the breech opening; and a dual action retention pawl comprising: a base operably attached to the barrel of the gun; and a pawl arm and an activation arm operably attached to the base such that the pawl arm pivots to a retracted position in response to an ammunition component engaging the activation arm when the ammunition component is loaded into the breech opening and returns to a retention position once the ammunition component is loaded to retain the ammunition component within the barrel of the gun, and the pawl arm pivots to the retracted position in response to the breech block engaging the activation arm when the breech block is moved to close the breech opening.
  • 10. The breech loading gun of claim 9, wherein the retention pawl at least partially nests in the activation arm when in the retracted position.
  • 11. The breech loading gun of claim 9, and further comprising a first biasing mechanism that biases the activation arm to the retention position.
  • 12. The breech loading gun of claim 9, wherein the activation arm has a U-shaped configuration with a first leg and a second leg, and wherein the activation arm is attached to the base intermediate the first leg and the second leg.
  • 13. The breech loading gun of claim 9, and further comprising:a first connecting member operably attaching the activation arm to the retention pawl; and a second connecting member operably attaching the retention pawl to the base.
  • 14. The breech loading gun of claim 13, and further comprising a second biasing mechanism that biases the retention pawl to the retention position.
  • 15. The breech loading gun of claim 9, and further comprising a sensor mechanism that senses when the activation arm is in the retention position.
  • 16. The propellant retention device of claim 15, wherein the sensor mechanism includes a cam operably attached to the activation arm.
  • 17. A method of retaining propellant increments in a gun barrel, the method comprising:providing a gun barrel having a bore extending therethrough and having a breech end; attaching a retention pawl with respect to the gun barrel so that the retention pawl is pivotable between a retention position at least partially in the bore and a retracted substantially position outside the bore; attaching an activation arm with respect to the gun barrel; and operably connecting the activation arm to the retention pawl so that pivoting of the activation arm between a retention position and a retracted position causes the retention pawl to pivot between the retention position and the retracted position.
  • 18. The method of claim 17, and further comprising loading propellant increments into the breech end of the gun barrel through the bore, wherein the propellant increments cause the retention pawl and the activation arm to move from the retention position to the retracted position as the propellant increments are passing into the breech end of the gun barrel.
  • 19. The method of claim 18, and further comprising sliding a breech block to cover the bore, wherein the breech block causes the retention pawl and the activation arm to move from the retention position to the retracted position as the breech block slides over the breech end of the gun barrel.
  • 20. The method of claim 18, wherein the retention pawl and the activation arm move from the retracted position to the retention position after the propellant increments pass into the breech end of the gun barrel.
  • 21. The method of claim 18, wherein the propellant increments are loaded into the gun barrel along a central axis thereof.
  • 22. The method of claim 17, and further comprising moving a breech block to cover the breech end of the gun barrel bore, wherein the breech block causes the retention pawl and the activation arm to move from the retention position to the retracted position.
  • 23. The method of claim 22, wherein the breech block is moved substantially perpendicular to a central axis of the gun barrel.
  • 24. The method of claim 17, wherein the retention pawl at least partially nests in activation arm when in the retracted position.
  • 25. The method of claim 17, wherein the activation arm and the retention pawl pivot towards each other when moving from the retention position to the retracted position.
  • 26. The method of claim 17, and further comprising biasing the activation arm to the retention position.
  • 27. The method of claim 17, and further comprising operably attaching the activation arm to the retention pawl with linkage having an over-center configuration.
  • 28. The method of claim 27, and further comprising:pivotally attaching the activation arm to the retention pawl with a first connecting member; and pivotally attaching the retention pawl to the base with a second connecting member.
  • 29. The method of claim 17, and further comprising biasing the retention pawl to the retention position.
  • 30. The method of claim 17, and further comprising sensing when the activation arm is in the retention position.
  • 31. A method of securing ammunition in a breech loading gun, the method comprising:providing a barrel with a bore aligned along a longitudinal axis thereof, wherein the barrel has a breech opening; mounting a breech block to the barrel proximate the breech opening; operably attaching a base to the barrel proximate breech opening; operably attaching a pawl arm and an activation arm to the base; pivoting the pawl arm to a retracted position in response to an ammunition component when the ammunition component is loaded into the breech opening; pivoting the pawl arm to a retention position once the ammunition component is loaded to retain the ammunition component within the barrel of the gun; and pivoting the pawl arm to the retracted position in response to the breech block engaging the activation arm when the breech block is moved to close the breech opening.
  • 32. The method of claim 31, wherein the retention pawl moves from the retracted position to the retention position after the propellant increment passes into the breech end.
  • 33. The method of claim 31, wherein the retention pawl at least partially nests in activation arm when in the retracted position.
  • 34. The method of claim 31, wherein the activation arm and the retention pawl pivot towards each other when moving from the retention position to the retracted position.
  • 35. The method of claim 31, and further comprising biasing the activation arm to the retention position.
  • 36. The method of claim 31, and further comprising operably attaching the activation arm to the retention pawl with linkage having an over-center configuration.
  • 37. The method of claim 36, and further comprising:pivotally attaching the activation arm to the retention pawl with a first connecting member; and pivotally attaching the retention pawl to the base with a second connecting member.
  • 38. The method of claim 31, and further comprising biasing the retention pawl to the retention position.
  • 39. The method of claim 31, and further comprising sensing when the activation arm is in the retention position.
US Referenced Citations (24)
Number Name Date Kind
3500718 Stoner Mar 1970 A
4393748 Hallqvist Jul 1983 A
4457209 Scheurich et al. Jul 1984 A
4495853 Gottwaldt Jan 1985 A
4677894 Pongratz et al. Jul 1987 A
4763559 Bouillon Aug 1988 A
4823675 Sciele et al. Apr 1989 A
4852461 von Laar et al. Aug 1989 A
4860633 Wiethoff et al. Aug 1989 A
4991489 Lindberg Feb 1991 A
5223663 Bender-Zanoni et al. Jun 1993 A
5261310 Sullivan et al. Nov 1993 A
5335581 Simon et al. Aug 1994 A
5526730 Zangrando Jun 1996 A
5563363 Soulaigre et al. Oct 1996 A
5591932 Staiert et al. Jan 1997 A
5677507 Becker et al. Oct 1997 A
5773747 Tellander et al. Jun 1998 A
5811721 Andersson Sep 1998 A
5831201 Andersson et al. Nov 1998 A
5837923 Gay et al. Nov 1998 A
5844163 Lindskog Dec 1998 A
5880395 Krumm et al. Mar 1999 A
6026729 Hallqvist Feb 2000 A
Foreign Referenced Citations (2)
Number Date Country
2260390 Apr 1993 GB
3-291497 Dec 1991 JP
Non-Patent Literature Citations (1)
Entry
Web site print-out: FAS Military Analysis Network, Crusader, 6 pgs., Nov. 21, 2000.