Adjustable Weight System for Sporting Equipment with Hollow Shafts

Abstract

A variable and adjustable weight system is integrated into the hollow shaft of an item of sporting equipment. These items might be hockey sticks, lacrosse sticks, field-hockey sticks, hurleys, bats, or golf clubs. The system employs a weight that slides longitudinally along the inside of the hollow shaft. This movement enables dynamic, or player-controlled, adjustments to the equipment's center of balance and swing-weight. The weight is dimensioned to have a gap between its outer surface and the inner walls of the shaft. A hole extends through it. These features allow fluid in the shaft to be displaced as the weight moves. The viscosity of this fluid, and the dimensions of the gap and hole, can influence the weight's movement, with thicker fluids providing more dampening. Fluids may be a liquid, like water or an oil-based solution, potentially with antifreeze properties, or a gas like air at ambient or pressurized levels.

1 . An apparatus for sporting equipment comprising:
 providing the sporting equipment having an elongate hollow shaft having an inner wall, a handle end and a blade end; and   a weight disposed within the hollow shaft, the weight configured to slide longitudinally within the hollow shaft between the handle end and the blade end;   wherein   a center of balance and a swing-weight of the sporting equipment is dynamically changed during a swing of the sporting equipment.   
     
     
         2 . The apparatus of  claim 1  further comprising:
 a gap located between an outer surface of the weight and the inner wall of the hollow shaft; wherein 
 fluid in the hollow shaft is displaced by movement of the weight as the weight moves and fluid flows through the gap. 
 
     
     
         3 . The apparatus of  claim 1  further comprising:
 a hole extending through the weight; wherein 
 fluid in the hollow shaft is displaced by movement of the weight as the weight moves and fluid flows through the hole. 
 
     
     
         4 . The apparatus of  claim 2  wherein:
 the fluid in the hollow shaft is a liquid. 
 
     
     
         5 . The apparatus of  claim 2  wherein:
 the fluid in the hollow shaft is a gas. 
 
     
     
         6 . The apparatus of  claim 5  wherein:
 the gas is pressurized. 
 
     
     
         7 . The apparatus of  claim 5  wherein:
 the gas is at ambient pressure. 
 
     
     
         8 . The apparatus of  claim 1  further comprising:
 a lower spring mechanism coupled to the weight and to a portion of the hollow shaft proximal to the blade end; and 
 an upper spring mechanism coupled to the weight and to a portion of the hollow shaft proximal to the handle; wherein 
 the lower spring mechanism and upper spring mechanism are configured to hold the weight at a rest position within said hollow shaft, where forces from the upper spring mechanism and lower spring mechanism are substantially equal, and to oppose movement of the weight during a swing of the sporting equipment. 
 
     
     
         9 . The apparatus of  claim 8  wherein the lower spring mechanism and upper spring mechanism are selected from the group consisting of:
 elastic cords, extension springs, compression springs and gas springs. 
 
     
     
         10 . The apparatus of  claim 1  further comprising:
 a locking mechanism configured to secure the weight at a longitudinal position within the hollow shaft. 
 
     
     
         11 . The apparatus of  claim 1  further comprising:
 at least one damper positioned at an end of the hollow shaft; wherein 
 the damper is configured to absorb impact from the weight.