Dart with adjustable weight

Abstract

A dart having a substantially hollow shaft and one or a plurality of removable weights to be placed in the lumen of the shaft so that the weight of the dart is adjustable and there is a secondary momentum when the dart hits a dartboard, wherein the weight is magnetic or non-magnetic.

1 . A dart that comprises an internal movable magnetic weight, which magnetic weight is slidable within the dart along a longitudinal axis of the dart.  
   
   
       2 . A dart according to  claim 1 , wherein the dart comprises a shaft having a front end and the magnetic weight is slidably movable into a position adjacent to the front end of the shaft.  
   
   
       3 . A dart according to  claim 2 , wherein the dart further comprises a point that extends outward from the front end of the shaft.  
   
   
       4 . A dart according to  claim 2 , wherein at least one of the shaft and the magnetic weight includes at least one through-bore that equalizes pressure on at least one side of the magnetic weight within the shaft.  
   
   
       5 . A dart according to  claim 2 , wherein at least one of the shaft and the magnetic weight includes at least one surface groove that equalizes pressure on at least one side of the magnetic weight within the shaft.  
   
   
       6 . A dart according to  claim 2 , wherein fixed magnets are provided at opposite ends of the shaft and the slidable magnetic weight is oriented so that magnetic poles of the slidable magnetic weight face like magnetic poles of the fixed magnets at the opposite ends of the shaft.  
   
   
       7 . A dart according to  claim 2 , wherein at least one of an inner surface of the shaft and an outer surface of the magnetic weight is provided with alignment structures that align central axes of the shaft and magnetic weight with one another.  
   
   
       8 . A dart according to  claim 2 , wherein the magnetic weight is removably and replaceably provided in the shaft.  
   
   
       9 . A dart that comprises: 
 a shaft having opposite ends and a central hollow lumen;    a tail piece configured to receive and support aerodynamic fins;    a head that is configured to become attached to a dartboard; and    at least one weight that is movable within the lumen of the shaft,    wherein at least one of the shaft and the at least one weight are configured to equalize pressure on at least one side of the weight within the shaft.    
   
   
       10 . A dart according to  claim 9 , wherein the at least one of the shaft and the weight includes at least one through-bore that equalizes pressure on at least one side of the weight within the shaft.  
   
   
       11 . A dart according to  claim 9 , wherein at least one of the shaft and the at least one weight includes at least one surface groove that equalizes pressure on at least one side of the weight within the shaft.  
   
   
       12 . A dart according to  claim 9 , wherein at least one of an inner surface of the shaft and an outer surface of the weight is provided with alignment structures that align central axes of the shaft and weight with one another.  
   
   
       13 . A dart according to  claim 9 , wherein the magnetic weight is removably and replaceably provided in the shaft.  
   
   
       14 . A dart according to  claim 9 , wherein the head of the dart is pointed.  
   
   
       15 . A dart according to  claim 9 , wherein the head of the dart is magnetic.  
   
   
       16 . A dart according to  claim 9 , wherein the at least one weight is magnetic.  
   
   
       17 . A dart according to  claim 16 , wherein fixed magnets are provided at opposite ends of the shaft and at least one magnetic weight is oriented so that magnetic poles of the at least one magnetic weight face like magnetic poles of the fixed magnets at the opposite ends of the shaft.  
   
   
       18 . A dart according to  claim 9 , wherein the at least one weight comprises a liquid.  
   
   
       19 . A dart according to  claim 9 , wherein the shaft comprises at least two portions that can be coupled together.