Patent Application
20080051002
The preferred embodiment of the invention is shown in
The sword of the present invention comprises a rigid housing 102 which includes the guard 104, a rigid blade base 106, and the hilt 108. Specifically, the elongate housing comprises the sword's hilt and the base of the blade together with the guard, in a rigid and unitary arrangement, with the hilt 108 and blade base 106 coaxially aligned.
A cylindrical hollow inner chamber 112 is disposed within the housing, extending from the forward end 114 of the base of the blade, back and through the rearmost end 116 of the hilt. The rear end of the chamber 116, and thus of the hilt, is open, and is adapted to receive piston 120, which freely fits within the open end 116 of the hilt and slides longitudinally within the inner chamber 112 to increase or decrease the volume of the chamber. The air volume within chamber is thusly increased as the piston is pulled rearwardly away from the housing during an expansion stroke and is decreased as the inner housing is pushed back forwardly into the housing during a compression stroke.
The expansion stroke is limited by extension tether 122, which connects the piston to the housing in a manner that allows free longitudinal relative movement between the piston and housing, but which retains the piston from pulling completely free from the housing. Tether 122 is comprised of a non-stretchable string, to abruptly deny rearward motion of the piston as it nears the point where continued motion would cause its removal from the housing. Alternatively, tether could be made of an elastic string and could assist to pull the piston back into the housing when it has been left accidentally extended.
The compression stroke is limited by contact between the rear most end 116 of the hilt and the forward edge 124 of pommel 126 at the rearmost end of the piston, which is too large in diameter to fit into the chamber.
With the piston inserted into chamber 112, the chamber is closed except of an air exhaust hole 130, at the forward end 114 of the chamber and an air inlet valve 132 at the rearward pommel end of the piston. The air inlet valve 132 comprises a plurality of holes 134 through the rearward end 136 of the pommel 126 which allow pneumatic communication between chamber 112 and the outer environment, and rubber stopper 140 disposed within the pommel which is adapted to move forward and rearward on longitudinal post 142 and is biased by the flow of air against or away from the plurality of holes 134. Incoming air during the expansion stroke forces the stopper 140 from the holes to allow air intake though the holes, as shown in
At the forward-most end of the blade's base is disposed hollow blade mounting shaft 150, which receives and positions the removable soft blade portion 152 that forms the battering and fencing portion and launchable portion of the blade.
The missile-shaped soft blade portion 152 is preferably made of closed-cell polyethylene foam to avoid injury and pain during fencing, or when used as a missile which may be launched from the sword. Other materials may be substituted for polyethylene foam, such as ethylene vinyl acetate closed-cell foam, neoprene foam, or numerous similarly soft and sufficiently dense materials. The elongate blade portion 152 comprises a hollow base portion 154 which fittingly mates with the housing's mounting shaft 150, a solid shaft portion 156, and a bullet-shaped tip 158.
During normal fencing play, the fitted attachment of the hollow base portion 154 of soft blade portion 152 onto the mounting shaft 150 is sufficiently snug to hold the blade portion 152 onto the housing 102 without inadvertent removal, and the skeletal support provided to the soft blade portion by the rigid mounting shaft 150 is sufficient to allow the user to poke and batter opponents without having the blade collapse or bend.
The hollow interior 160 of the mounting shaft 150 communicates pneumatically with the air exhaust hole 130 so that air forced from chamber 112 by the decreasing chamber volume during the compression stroke of the piston is directed through exhaust hole 130, through the mounting shaft 150, and is forced out through launching hole 162 at the forward tip 164 of the mounting shaft in a powerful blast.
During play fencing, the user may at anytime decide to launch the soft blade portion as a missile towards an opponent in a surprise attack, as follows;
First, while holding the hilt 108 with one hand, the user grasps the pommel 126 with the other hand and pulls it rearward as far as the tether 122 will allow. Expansion of the chamber 112 caused by the motion of the piston 120 relative to the housing 102, as shown in
Subsequent rapid compression of piston 120 relative to the housing, as shown in
The fit of the missile-shaped launchable blade portion 152 to the mounting shaft 150, which is sufficiently snug for fencing and battering play, is insufficient to retain the blade portion on the shaft against the force of the powerful blast, and the blade portion 152 is rapidly ejected from the post as a missile, as shown in
Because the rearward portion 154 of soft blade portion 152 is hollow for mating with mounting shaft 150, it is lighter than the solid forward portion of the blade portion and the center-of-mass of the missile is substantially forward of the blade portion 152. The missile is therefore especially well-adapted for missile-like trajectory, with hollow rear portion 154 serving basically as a stabilizing tail during flight.
This positioning of the center of mass and the aerodynamic shape of the elongate foam blade with its bullet-shaped tip 158 make it well adapted for flight and suited for accurate aiming. During propulsion of tip through the air, this arrangement causes the missile to maintain a stabile and straight course, without tumbling, curving, or erratic movement.
One can also readily appreciate that by use of the sword's pommel 126 to actuate the propulsion of the missile and the disguising of the blade portion 152 as an integral part of the sword, it allows the user to surprise opponents who may not be aware of the missile-firing function of sword. In fact, one using the sword in its typical fencing mode and thereby grasping it by the pommel needs only to quickly draw back and forth on the pommel while aiming the sword at the opponent, to fire an unexpected missile. The invention allows the user a surprising option while battling against his/her foes.
It will be appreciated by those skilled in the applicable arts that the foregoing is merely one of many possible embodiments of the invention, and that the invention should therefore only be limited according to the following claims.
