Mechanical broadhead arrowhead with force adjustment feature

Abstract

A mechanical broadhead arrowhead for use with an arrow in archery. The arrowhead has a ferrule with a cylindrical threaded base and blades pivotally mounted to the ferrule. The arrowhead has a force adjustment member which is operable by a user to vary the force imparted on the blades to maintain the blades in a closed position during flight of the arrow.

What is claimed is: 
     
         1 . An arrowhead for use with an arrow in archery, comprising:
 a ferrule including a ferrule body having a distal tip end and an internally threaded proximal end, the ferrule body including a slot;   at least one blade having a pivot end pivotally mounted to the ferrule body and at least partially disposed within the slot, the blade further including a forward cutting edge and a rear edge, the pivot end including a first detent, wherein the blade is pivotable relative to the ferrule body between a closed position and an open position; and   a retaining mechanism received within the proximal end of the ferrule body, the retaining mechanism comprising:
 a detent member; 
 an externally threaded adjustment member having a proximal end threadingly received within the internally threaded proximal end of the ferrule body; and 
 a biasing member disposed between the adjustment member and the detent member, the biasing member exerting a biasing force on the detent member and wherein an extent of threaded receipt of the adjustment member within the ferrule body is operable to vary a biasing force of the biasing member. 
   
     
     
         2 . The arrowhead of  claim 1 , wherein:
 the biasing member exerts a greater biasing force on the detent member when the adjustment member is threadingly received within the internally threaded proximal end of the ferrule body to a greater extent; and   the biasing member exerts a lesser biasing force on the detent member when the adjustment member is threadingly received within the internally threaded proximal end of the ferrule body to a lesser extent.   
     
     
         3 . The arrowhead of  claim 1 , wherein the slot extends longitudinally along the ferrule body, the at least one blade received within the slot. 
     
     
         4 . The arrowhead of  claim 1 , wherein, in the closed position, the at least one blade is disposed closely adjacent the ferrule body with the forward cutting edge substantially received within the slot. 
     
     
         5 . The arrowhead of  claim 4 , wherein the detent member is received within the first detent when the at least one blade is in the closed position. 
     
     
         6 . The arrowhead of  claim 1 , wherein, in the open position, the at least one blade is disposed at an angle outwardly of the ferrule body with the forward cutting edge exposed toward the distal tip end of the ferrule body. 
     
     
         7 . The arrowhead of  claim 6 , wherein the pivot end of the at least one blade includes a second detent, and wherein the detent member is received within the second detent when the at least one blade is in the open position. 
     
     
         8 . The arrowhead of  claim 1 , in combination with an arrow having an elongated shaft with an internally threaded distal end into which a proximal end of the externally threaded adjustment member is threadingly received to attach the arrowhead to the arrow. 
     
     
         9 . The arrowhead of  claim 1 , wherein the adjustment member is a set screw. 
     
     
         10 . The arrowhead of  claim 1 , wherein the biasing member is a coil spring. 
     
     
         11 . The arrowhead of  claim 1 , wherein the detent member is a ball bearing. 
     
     
         12 . The arrowhead of  claim 1 , further comprising a pair of blades including the at least one blade. 
     
     
         13 . The arrowhead of  claim 12 , wherein the retaining mechanism limits a maximum deployment angle of the blades in a range of about 90 degrees to 180 degrees relative to a longitudinal axis of the ferrule. 
     
     
         14 . A method of configuring an arrowhead for flight, comprising:
 adjusting an extent of threaded insertion of a distal end of a threaded adjustment member into an internally threaded proximal end of a slotted ferrule body to vary a biasing force of a biasing member against at least one pivoting blade; and   threading a proximal end of the threaded adjustment member into an internally threaded distal end of an arrow to attach the arrowhead to the arrow.   
     
     
         15 . The method of  claim 14 , wherein the ferrule body includes a longitudinally extending slot, the at least one pivoting blade received within the slot. 
     
     
         16 . The method of  claim 14 , further comprising manually moving the at least one pivoting blade to a closed position in which the at least one pivoting blade is received within the slot. 
     
     
         17 . The method of  claim 14 , wherein the at least one pivoting blade further includes a forward cutting edge and a rear edge, and a pivot end including a first detent, wherein the at least one pivoting blade is pivotable relative to the ferrule body between a closed position and an open position, and the arrowhead further comprises:
 a retaining mechanism received within the proximal end of the ferrule body, the retaining mechanism comprising:
 a detent member; 
 an externally threaded adjustment member having a proximal end threadingly received within the internally threaded proximal end of the ferrule body; and 
 a biasing member disposed between the adjustment member and the detent member, the biasing member exerting a biasing force on the detent member and wherein an extent of threaded receipt of the adjustment member within the ferrule body is operable to vary a biasing force of the biasing member. 
   
     
     
         18 . The method of  claim 17 , wherein the biasing member exerts a greater biasing force on the detent member when the adjustment member is threadingly received within the internally threaded proximal end of the ferrule body to a greater extent; and
 the biasing member exerts a lesser biasing force on the detent member when the adjustment member is threadingly received within the internally threaded proximal end of the ferrule body to a lesser extent.