Projectile with aft-mounted cutting edges

Abstract

A projectile includes an elongated shaft having a fore-end and an aft-end. A nose portion is affixed to the fore-end of the shaft, and cutting edges are attached near the aft-end of the shaft. For the present invention, the nose portion of the projectile is preferably made of a material having a greater density than the material that is used to construct the shaft of the projectile. In any event, the structure and configuration of the projectile is such that its center of gravity is located in the forward half of the projectile. Also, the cutting edges at the aft-end of the shaft can be configured to function as stabilizing fins for the projectile in flight.

What is claimed is: 
     
         1 . A projectile which comprises:
 an elongated shaft defining an axis and having a fore-end and an aft-end, wherein the shaft has a length (L s ) and is made of a material having a first mass per unit length (m 1 );   a nose portion affixed to the fore-end of the shaft, wherein the nose portion has a length (L n ) and is made of a material having a second mass per unit length (m 2 ), wherein m 2  is greater than m 1  (m 2 >m 1 ), with a consequent center of gravity for the projectile located substantially on the axis at a distance more than ½(L n +L s ) from the aft-end of the shaft; and   at least one cutting edge attached to the shaft and projecting outwardly in a radial direction from the axis.   
     
     
         2 . A projectile as recited in  claim 1  wherein the nose portion has an outer surface formed with a shape selected from a group comprising ellipsoidal, cylindrical and spherical. 
     
     
         3 . A projectile as recited in  claim 1  further comprising a plurality of stabilizing fins mounted adjacent the aft-end of the shaft. 
     
     
         4 . A projectile as recited in  claim 3  wherein at least one stabilizing fin is formed with a cutting edge. 
     
     
         5 . A projectile as recited in  claim 1  wherein the aft-end of the shaft is flared outwardly in a radial direction from the axis to establish a circular cross-section with a maximum diameter (D max ), and wherein the nose portion is formed to have a circular cross-section with a substantially same maximum diameter (D max ). 
     
     
         6 . A projectile as recited in  claim 1  wherein the m 1  material is selected from a group comprising aluminum, magnesium, beryllium, carbon fibers, and fiber glass. 
     
     
         7 . A projectile as recited in  claim 1  wherein the m 2  material is selected from a group comprising brass, bronze, stainless steel, tungsten and depleted uraniuim. 
     
     
         8 . A projectile as recited in  claim 1  wherein the aft-end of the shaft is formed with a nock and a threaded receptacle, wherein the threaded receptacle is axially aligned and extends forward from the aft-end of the shaft to receive a tool therein for engagement therewith for retrieval of the projectile from a target. 
     
     
         9 . A projectile which comprises:
 an extended shaft of length “L” having a fore-end and an aft-end, wherein the extended shaft defines an axis and has a mass distribution with a center of gravity located substantially on the axis within a distance of ½L from the fore-end of the extended shaft; and   a plurality of cutting edges attached to the extended shaft adjacent the aft-end thereof and projecting outwardly in a radial distance from the axis.   
     
     
         10 . A projectile as recited in  claim 9  wherein the extended shaft comprises:
 a shaft portion having a length (L s ), wherein the shaft portion is made of a material having a first mass per unit length (m 1 ); and 
 a nose portion formed at the fore-end of the extended shaft, wherein the nose portion has a length (L n ) and is made of a material having a second mass per unit length (m 2 ), wherein m 2  is greater than m 1 , L=L s +L n , and wherein L n  is less than 0.5L with a consequent center of gravity for the projectile located substantially on the axis at a distance more than ½(L n +L s ) from the aft-end of the shaft. 
 
     
     
         11 . A projectile as recited in  claim 10  wherein the nose portion has an outer surface formed with a shape selected from a group comprising ellipsoidal, cylindrical and spherical. 
     
     
         12 . A projectile as recited in  claim 10  further comprising a plurality of stabilizing fins mounted adjacent the aft-end of the shaft portion. 
     
     
         13 . A projectile as recited in  claim 12  wherein at least one stabilizing fin is formed with a cutting edge. 
     
     
         14 . A projectile as recited in  claim 10  wherein the aft-end of the extended shaft is flared outwardly in a radial direction from the axis to establish a circular cross-section with a maximum diameter (D max ), and wherein the nose portion is formed to have a circular cross-section with a substantially same maximum diameter (D max ). 
     
     
         15 . A projectile as recited in  claim 10  wherein the m 1  material is selected from a group comprising aluminum, magnesium, beryllium, carbon fibers, and fiber glass. 
     
     
         16 . A projectile as recited in  claim 10  wherein the m 2  material is selected from a group comprising brass, bronze, stainless steel, tungsten and depleted uranium. 
     
     
         17 . A method for manufacturing a projectile which comprises the steps of:
 providing an elongated shaft defining an axis and having a fore-end and an aft-end, wherein the shaft has a length (L s ) and is made of a material having a first mass per unit length (m 1 );   affixing a nose portion to the fore-end of the shaft, wherein the nose portion has a length (L n ) and is made of a material having a second mass per unit length (m 2 ), wherein m 2  is greater than m 1  (m 2 >m 1 ), with a consequent center of gravity for the projectile located substantially on the axis at a distance more than ½(L n +L s ) from the aft-end of the shaft; and   attaching at least one cutting edge to the shaft to project outwardly in a radial direction from the axis.   
     
     
         18 . A method as recited in  claim 17  wherein the attaching step comprises the steps of:
 mounting a plurality of stabilizing fins adjacent the aft-end of the shaft; and 
 forming at least one stabilizing fin with a cutting edge. 
 
     
     
         19 . A method as recited in  claim 17  further comprising the steps of:
 flaring the aft-end of the shaft outwardly in a radial direction from the axis to establish a circular cross-section with a maximum diameter (D max ); and 
 forming the nose portion to have a circular cross-section with a substantially same maximum diameter (D max ). 
 
     
     
         20 . A method as recited in  claim 17  further comprising the steps of:
 selecting the m 1  material from a group comprising aluminum, magnesium, beryllium, carbon fibers, and fiber glass; and 
 selecting the m 2  material from a group comprising brass, bronze, stainless steel, tungsten and depleted uraniuim.