The present invention is a self-propelled arrow, consisting of an otherwise conventional hunting or target practice arrow that is propelled by CO.sub.2 and water, thus providing additional thrust to the arrow when shot from a bow. String inertia causes a CO.sub.2 filled cartridge to strike the point of a puncture means which punctures the cartridge and releases charged CO.sub.2 into a water storage chamber which charges the water inside. The charged water becomes pressurized and actuates a pliable closure membrane to an open position in check valve fashion, thus releasing the pressurized water from the water storage chamber through the propellant jets in the rear of the arrow. This system accelerates the arrow and decreases the arrow drop, thereby increasing the range and speed of the arrow immensely. The CO.sub.2 cartridges may be replaceable.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates generally to archery equipment, and, more
 particularly, to a self-propelled arrow.
 2. Description of the Related Art
 The hobby of bow hunting or bow target shooting has been enjoyed by many.
 It is a hobby where skill is constantly employed and continual practice
 will continually improve a participant. However, it does have some
 drawbacks when compared to other similar hobbies using firearms. Perhaps
 the largest drawback is that of range capabilities. When arrows are
 launched from a bow, crossbow or other similar device, they quickly loose
 speed. As speed is lost, the arrow drops in its flight path and thus
 accuracy is affected as well. Another problem is that of a lack of thrust
 or penetrating power when the arrow finally reaches its target due to slow
 arrow speeds. While this is not a great concern while target practicing,
 it does become an issue while hunting. The lack of penetrating power may
 not allow for an instant kill of an animal and cause the animal to flee
 with the arrow attached. The hunter is then faced with subsequent tracking
 of the animal as it can live for several hours after being hit, depending
 upon the accuracy of the hunter's shot. When this occurs, several things
 could happen. The game could run so far and so fast that the hunter never
 catches up to it, or the wounded animal could be attacked by other wild
 animals, ruining the meat.
 A search of the prior art did not disclose any patents that read directly
 on the claims of the instant invention; however, the following references
 were considered related:
 U.S. Pat. No. 5,836,842, issued in the name of McLearan;
 U.S. Pat. No. 5,123,657, issued in the name of Colt et al.;
 U.S. Pat. No. 5,650,589, issued in the name of Thiesen;
 U.S. Pat. No. 5,610,365, issued in the name of Thiesen;
 U.S. Pat. No. 5,445,139, issued in the name of Bybee; and
 U.S. Pat. No. 4,478,202, issued in the name of Anderson.
 Consequently, the need has developed for a means by which bow hunters and
 target shooters can increase their range, accuracy and speed of their
 arrows in an efficient manner.
 SUMMARY OF THE INVENTION
 The present invention is a self-propelled arrow, consisting of an otherwise
 conventional hunting or target practice arrow that is propelled by
 CO.sub.2 and water, thus providing additional thrust to the arrow when
 shot from a bow.
 String inertia causes a CO.sub.2 ampule to strike a water storage chamber,
 charging the water, and thus releasing the pressurized water through
 propellant jets in the rear of the arrow. This system accelerates the
 arrow and decreases the arrow drop, thereby increasing the range and speed
 of the arrow immensely. The CO.sub.2 cartridges may be replaceable.
 It is an object of the present invention to provide an arrow that
 accelerates after being fired, thus increasing distance and reducing
 downward tipping of the arrow in flight.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
 The best mode for carrying out the invention is presented in terms of its
 preferred embodiment, herein depicted within the Figures.
 1. Detailed Description of the Figures
 Referring now to FIGS. 1-4, a self-propelled arrow 10 is disclosed,
 designed as an otherwise conventional arrow that is propelled by CO.sub.2
 and water 60, thus providing additional thrust to the arrow 20 when shot
 from a bow.
 The present invention is comprised of an otherwise conventional, linearly
 elongated, cylindrical arrow 20 having a forward end 22 opposite a rear
 end 24. Located at the forward end 22 of the arrow 20 is an arrow tip
 receiving neck 28. The arrow tip receiving neck 28 is a threaded, circular
 opening designed to have an arrow tip 26 removably coupled thereto. The
 arrow 20 has a hollow interior volume.
 A water storage chamber 50, designed to hold water 60 therein, is located
 inside the arrow 20, axially oriented, and extends a linear length from
 the rear end 24 just beyond a linearly elongated centerline to the forward
 end 22 of the arrow 20. The water storage chamber 50 is configured so as
 to be slidably received inside of the arrow 20 along a radial centerline
 thereof. The water storage chamber 50 further includes a small aperture
 118 formed along an external circumferential surface near an upper end 52
 thereof below a first pliable closure membrane 70 (as will be described in
 greater detail below) for delivering water 60 therethrough. The water
 storage chamber 50 is filled with water 60 by a water-delivery means 120
 such as a syringe with needle, or other suitable means for delivering
 water 60 inside the water storage chamber 50.
 The first spherical, pliable closure membrane 70, located on the upper end
 52 of the water storage chamber 50, is moved by a rearward thrust of
 charged CO.sub.2 between open and closed positions in check valve fashion.
 A second spherical, pliable closure membrane 72, located on a lower end 54
 of the water storage chamber 50, separates the water storage chamber 50
 from propellant jets 80.
 The propellant jets 80 are formed at the rear end 24 of the arrow 20,
 posterior to the pliable closure membrane 72, and have external
 circumferential sidewalls converging inwardly with increased distance from
 the pliable closure membrane 72. The pliable closure membrane 72 is moved
 by water 60 flow between open and closed positions in check valve fashion.
 When the pliable closure membrane 72 on the lower end 54 of the water
 storage chamber 50 is in an open position, the water storage chamber 50 is
 in fluid communication with the propellant jets 80. The propellant jets 80
 have a hollow, circular, threaded cap 100 mounted to an upper end thereof,
 so as to be held by a threaded connection to a tip of any arrow, thereby
 allowing the present invention to be removably attached to any typical
 arrow used in bow hunting.
 A replaceable cartridge 30, containing a pressurized gas 40 such as
 CO.sub.2, is designed to be slidably inserted and positioned inside the
 arrow 20, posterior to the arrow tip 22, where the cartridge 30 comes to
 rest against a spring safety means 90. The spring safety means 90 is
 affixed along a perimeter of an upper end of the first pliable closure
 member 70, located at the 52 top end of the water storage chamber 50, and
 includes a pointed, puncture means 65 resting therein, extending from the
 top end 52 of the water storage chamber 50 a linear distance just short an
 upper end of the spring safety means 90. The spring safety means 90
 prevents the cartridge 30 from striking the water storage chamber 50
 except during firing of the arrow 20.
 The present invention is designed so that string inertial force, created
 during the firing of the arrow 20 from a bow, causes the CO.sub.2
 pressurized cartridge 30 to be thrust rearward and strike the point of the
 puncture means 65, thereby puncturing the cartridge 30 and releasing
 charged CO.sub.2 into the water storage chamber 50, wherein the water 60
 therein becomes pressurized. The pressurized water 60 actuates the pliable
 closure membrane 72 to an open position in check valve fashion, and
 releases pressurized water 60 therefrom through the propellant jets 80.
 This CO.sub.2 /water propulsion system is designed to accelerate the arrow
 20 and decrease the arrow 20 drop, thereby increasing the range and speed
 of the arrow 20.
 After the charged CO.sub.2 has entered the water storage chamber 50, the
 first pliable closure membrane 70 is actuated to a closed position in
 check valve fashion. Similarly, after all pressurized water 60 has been
 released through the propellant jets 80, the second pliable closure
 membrane 72 is actuated to a closed position in check valve fashion,
 thereby placing the present invention in condition for being fired once
 again. At this point, a user removes the used CO.sub.2 cartridge 30 and
 inserts and positions another CO.sub.2 cartridge inside the arrow 20,
 posterior to the arrow tip 22, and fills the water storage chamber 50 with
 water 60, via the water-delivery means 120.
 Referring now to FIGS. 5 and 6, an alternate embodiment of the present
 invention is shown wherein a complete arrow 20 is utilized. The alternate
 embodiment comprises an arrow 20 having a plurality of arrow guide fins 33
 mounted to an external circumferential surface at the rear end 24 thereof.
 The alternate embodiment further includes propellant jets 80 having a
 V-shaped recess 82 formed at an end thereof, dividing the propellant jets
 80 into two water propulsion channels 84 and also serving as a bow string
 guiding means for launching the arrow 20. The alternate embodiment is
 identical in all other aspects of the preferred embodiment of the present
 invention, excluding the threaded cap 100 mounted to an upper end of the
 propellant jets 80.
 It is envisioned that other styles and configurations of the present
 invention can be easily incorporated into the teachings of the present
 invention, and only one particular configuration shall be shown and
 described for purposes of clarity and disclosure and not by way of
 limitation of scope.
 2. Operation of the Preferred Embodiment
 To use the present invention, the user fills the water storage container 50
 with water 60 via the water-delivery means 120, and slidably inserts the
 water storage container 50 inside of the arrow 20. Next, the user slidably
 inserts a CO.sub.2 cartridge 30 inside the arrow 20 where it comes to rest
 against the spring safety means 90, and secures an arrow tip 22 to the
 forward end 22 of the arrow 20. The user then removably secures the rear
 end 24 of the arrow 20 via the threaded cap 100 to the tip of an arrow.
 Finally, the user fires the arrow 20 in the customary manner as when
 firing a bow and arrow.
 The foregoing description is included to illustrate the operation of the
 preferred embodiment and is not meant to limit the scope of the invention.
 The scope of the invention is to be limited only by the following claims.