US 3738271 A
A grenade round containing a case with a telescopic tubular actuator, which is extended responsive to propellant discharge therein against the forwardly disposed grenade, is provided with a propellant wad which is unrolled and then is freed for forward impact against the extended actuator by residual discharge gas pressure to give forward momentum to the case after the grenade is propelled therefrom.
Description (OCR text may contain errors)
United States Patent [191 La Costa 1 June 12, 1973 GRENADE ROUND WITH MEANS GIVING FORWARD MOMENTUM TO THE FIRED CASE  Inventor: Nicholas J. La Costa, Phoenix, Md.
 Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.
22 Filed: Dec. 18,1970
21 Appl. No.: 99,698
 U.S. C1 102/38, 102/40, 102/652  Int. Cl F421) 5/02  Field of Search 102/38, 39, 40, 43 R,
 References Cited UNITED STATES PATENTS 3,404,598 10/1968 Angelos ..89/1B 3,249,010 5/1966 Blain et al.....' 102/39 X 3,119,302 1/1964 Barr 89/1 B 3,106,131 10/1963 Barr et a] 102/39 X liri ryjiym n rfli h St Att0rneyHarry M. Saragovitz, Edward J. Kelly, Herbert Berl and Albert E. Arnold, Jr.
 ABSTRACT A grenade round containing a case with a telescopic tubular actuator, which is extended responsive to propellant discharge therein against the forwardly disposed grenade, is provided with a propellant wad which is unrolled and then is freed for forward impact agaqnst the extended actuator by residual discharge gas pressure to give forward momentum to the case after the grenade is propelled therefrom.
6 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION which also includes a telescopically rolled tubular actuator which is unrolled, responsive to propellant discharge therein, against the grenade to propel it from the barrel.
SUMMARY OF THE INVENTION In the present state of development of this grenade round, the wad for containing the propellant and transmitting the gases generated by discharge thereof into the actuator is overly complex as to structure and costly to manufacture. Also, one of the military uses to which the round is being adapted requires that it be used with a grenade launcher having forward ejection. Through the present invention, the propellant wad is simplified so as to comprise a single, easily fabricated unit and this unit, after the grenade is launched, is arranged to impact responsive to residual gas pressure against its front end of the actuator to give added forward momentum to the fired case for forward ejection thereof from the launcher.
It is therefore a principal object of this invention to modify such round in its present form so as to simplify its structure and reduce its weight and cost.
It is a further object of this invention to provide such a round with means for imparting forward momentum to the case after the grenade is launched therefrom so as to provide forward ejection of the case from a particular launcher.
It is a still further object of this invention to provide within the actuator chamber of such round a propellant wad comprising a telescopic cupshape diaphragm which holds the propellant and isolates it from the enveloping actuator chamber and which, when the grenade is propelled from the case, impacts against the front end of the extended actuator to give added forward momentum to the case.
Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawing which is for the purpose of illustration only.
BRIEF DESCRIPTION'OF THE DRAWING FIG. 1 is a longitudinally cross-sectioned view of a live grenade round in accordance with the present invention;
DESCRIPTION OF A PREFERRED EMBODIMENT Shown in the drawing in a round 12 comprising a case 14 with a grenade 15 located therein for launching responsive to propellant discharge. Case 14 includes a barrel 16 which may be fabricated from reinforced plastic where weight is a design factor and which is provided with a bore 18 that is open at the front end. An annular flange 20 extends integrally around the inside of barrel 16 at its rear end to form an annular shoulder 22 and an axial hole 24. Located in hole 24, as by press fit, is a base member 26 which includes a cylindrical recess 28 formed therein from the front face thereof, an aperture 30 extending coaxially through the base member from the bottom of the recess, and an integral ring 32 formed around the outside of the base member between the inside and the outside ends thereof so as to be positioned forwardly of flange 20. The outside diameter of ring 32 is slightly less than that of bore 18 at shoulder 22 as hereinafter described.
Case 14 also comprises an extendable actuator 34 of tubular configuration which is open at one end 36 and closed at the opposite end 37. Open end 36 is anchored to case 14 and sealed thereat by the engagement of such end between shoulder 22 and rings 32 and between the circumference thereof and the inside bore 18 to form a sealed chamber 38 within the actuator.
Closed end 37 of actuator 34 is rolled inwardly thereinto and then outwardly, as shown in FIG. 1, to form, in cross-section, an outer section 39 of U-configuration and an inner section 40 of reversed U-configuration extending therefrom to permit unrolling, telescopic extension of the actuator when gas pressure is applied to chamber 38. Closed end 37 of actuator 34 is depressed to form outside thereof a reentrant portion having an external concavity 42 which receives the rounded end of grenade l5 and an internal convexity 44 located within chamber 38. As fully disclosed in US Pat. Nos. 3,119,302 and 3,404,598, actuator 34 is fabricated from a suitable material which permits the actuator to be unrolled and extended telescopically incident to increased pressure within chamber 38.
Located within chamber 38 is propellant wad 48 which is also fabricated from a suitable material which will permit the wad to be unrolled from a telescopic configuration. Wad 48 is tubular in configuration with an outside diameter which is substantially the same as diameter of recess 28, and comprises an open end 50 with a lip 52 therearound and a closed end 54. Closed end 54 is rolled inwardly to form a cylindrical receptacle 55 having a circumferential double-wall 56 of U- configuration in cross-section including a rolled edge 57. Double-wall 56 is inserted into recess 28, as shown in FIG. 1, to where edge 57 has contact with the bottom thereof, and lip 52 has contact with convexity 44 to retain wad 48 seated within the recess and to maintain the edge in contact with the bottom of the recess thereby to enclose propellant 58 in receptacle 55 for discharge by primer 60 installed in aperture 30.
Round 12 is fired to launch grenade 15 by detonation of primer 60 which efl'ects discharge of propellant 58 and the generation of gases in receptacle 55. Responsive to this gas pressure, receptacle 55 is displaced telescopically forwardly, unrolling its double-wall 56 to where fold 57 is disposed above base member 26 and in contact with convexity 44, as shown in FIG. 2, permitting the discharge. gases to escape laterally from the receptacle into chamber 38. Responsive to this gas pressure, actuator 34 is displaced forwardly to propel grenade 15 forwardly along bore 18 of barrel 16 and into flight. Then, propellant wad 48, which is freed by the forward unrolling of actuator 34, impacts the front end thereof, responsive to residual gas pressure in receptacle 56, to give forward momentum to case 14 through the now extended actuator which is anchored at its rear end to the case. This momentum, in addition to that imparted to case 14 by the forward extension of actuator 34 therein, is sufficient to achieve the forward ejection of the case from the particular launcher.
I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.
1. In a grenade round comprising a case with a barrel having a telescopic actuator therein, and a grenade located within said barrel for propulsion therefrom responsive to forward extension of said telescopic actuator by discharge gas pressure admitted to a chamber therein, the improvement comprising a propellant wad including a receptacle for the propellant, and means forming a part of said case cooperating with said actuator for retaining said wad within said chamber when said actuator is in telescopic configuration and for releasing said wad for subsequent impact against said actuator when extended forwardly responsive to gas pressure transmitted into said chamber from said receptacle.
2. The invention as defined in claim 1 wherein said wad is of a tubular configuration and comprises a closed end folded inwardly to form said receptacle and permit forward extension thereof responsive to propellant discharge therein, said receptacle being disposed in cooperation with a base member of said case for enclosing said propellant for primer discharge.
3. The invention as defined in claim 2 and including cooperating means in said wad and said base member for opening communication between said receptacle and said chamber during forward extension of said receptacle responsive to discharge of said propellant.
4. The invention as defined in claim 2 wherein said actuator includes a concavity for receiving the rear end of said grenade and said wad includes an open end, and wherein said means comprises a spherical convexity formed within said chamber by said concavity, and a lip around said open end disposed in contact with said convexity when said actuator is in its telescopic configuration and is released for free forward displacement when said actuator is in its extended configuration.
5. The invention as defined in claim 3 wherein said base member includes a cylindrical recess within the inner end thereof, and said receptacle includes a double-wall section deformable responsive to propellant discharge in said receptacle for forward extension thereof, said double wall section being insertable within said recess to enclose said propellant within said receptacle.
6. The invention as defined in claim 5 wherein said double-wall section includes a rolled edge forwardly displaceable by forward extension of said receptacle, and wherein said cooperating means in said wad and said base member comprises said double-wall section with said rolled edge thereof and said recess whereby communication is provided between said receptacle and said chamber when said rolled edge clears said recess responsive to forward extension of said receptacle.