U.S. patent application number 11/038684 was filed with the patent office on 2005-09-01 for arrow gun method and apparatus.
Invention is credited to Berry, David L..
Application Number | 20050188979 11/038684 |
Document ID | / |
Family ID | 34807046 |
Filed Date | 2005-09-01 |
United States Patent
Application |
20050188979 |
Kind Code |
A1 |
Berry, David L. |
September 1, 2005 |
Arrow gun method and apparatus
Abstract
A gun (100 and 400) for using compressed gas from a compressed
gas cartridge (106) to propel an arrow (102). The gun includes a
barrel (104) for receiving the arrow and a compressed gas storage
chamber (122 and 422). The compressed gas storage chamber is
adapted to receive and store compressed gas in an expanded state
from the compressed gas cartridge for later release. The gun also
includes a valve assembly (130 and 430) for selectively releasing
the compressed gas stored in the compressed gas storage chamber
within the barrel for propelling the arrow out the barrel.
Inventors: |
Berry, David L.; (Tonasket,
WA) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE
SUITE 2800
SEATTLE
WA
98101-2347
US
|
Family ID: |
34807046 |
Appl. No.: |
11/038684 |
Filed: |
January 18, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60536761 |
Jan 15, 2004 |
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Current U.S.
Class: |
124/76 |
Current CPC
Class: |
F42B 14/064 20130101;
F42B 6/06 20130101; F41B 11/62 20130101 |
Class at
Publication: |
124/076 |
International
Class: |
F41B 011/00 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A gun for using compressed gas from a compressed gas cartridge
to propel an arrow, the gun comprising: (a) a barrel for receiving
an arrow; (b) a compressed gas storage chamber adapted to receive
and store compressed gas in an expanded state from a compressed gas
cartridge for later release; and (c) a valve assembly for
selectively releasing the compressed gas stored in the compressed
gas storage chamber within the barrel for propelling the arrow out
the barrel.
2. The gun of claim 1, wherein the compressed gas storage chamber
has a volume which exceeds a volume of the compressed gas cartridge
by between about two to about twelve times.
3. The gun of claim 1, further including a charge indicator in
communication with the compressed gas storage chamber, the charge
indicator having a raised position indicating a presence of the
compressed gas in the compressed gas storage chamber and a lowered
position indicating an absence of the compressed gas in the
compressed gas storage chamber.
4. The gun of claim 3, wherein the charge indicator is
automatically transitioned from the lowered position to the raised
position by a pressure exerted upon the charge indicator by the
compressed gas.
5. The gun of claim 1, further including an arrow holding assembly
for releasably holding an arrow within the barrel prior to release
of the compressed gas within the barrel and for releasing the arrow
once the compressed gas is released within the barrel.
6. A gun for using compressed gas to propel a standard length
arrow: (a) a barrel of a length about 22 inches or greater for
receiving a standard length arrow within the barrel; and (b) a
valve assembly for selectively releasing a compressed gas from a
compressed gas source into the barrel for propelling the standard
length arrow out of the barrel.
7. The gun of claim 6, wherein the barrel is about 28 inches or
greater in length.
8. The gun of claim 6, wherein the barrel is about 30 inches or
greater in length.
9. The gun of claim 6, further including a compressed gas storage
chamber for receiving and storing the compressed gas from the
compressed gas source for later release by the valve assembly into
the barrel.
10. The gun of claim 9, wherein the compressed gas source is a
compressed gas cartridge of a selected volume, and wherein the
storage chamber has a volume exceeding the selected volume of the
compressed gas cartridge such that the compressed gas is permitted
to expand and be held in an expanded state prior to being released
into the barrel by the valve assembly.
11. A method of propelling an arrow from a gun having a barrel, a
trigger, and a compressed gas storage chamber, the method
comprising: (a) placing an arrow in the barrel; (b) discharging a
compressed gas into the compressed gas storage chamber for storage
therein; and (c) activating the trigger to cause the compressed gas
to be released from the compressed gas storage chamber into the
barrel to cause the arrow to be propelled from the barrel.
12. The method of claim 11, wherein the arrow is 22 inches or
greater in length.
13. The method of claim 11, further including discharging the
compressed gas from a compressed gas cartridge into the compressed
gas storage chamber.
14. The method of claim 13, wherein a volume of the compressed gas
storage chamber exceeds a volume of the compressed gas cartridge by
about two to about twelve times.
15. A fletching adapted to be attached to a proximal end of an
arrow shaft to aid in the propelling of the arrow shaft by
compressed gas out of a barrel having an inner diameter defined by
an inner surface of the barrel, the fletching comprising: (a) an
attachment member adapted to couple the fletching to a proximal end
of an arrow shaft; and (b) an elongate body coupled to the
attachment member, the elongate body having a sealing member having
an outer diameter substantially equal to the inner diameter of the
barrel such that the sealing member impedes at least a substantial
portion of the compressed gas from flowing past the sealing member
when the sealing member is in the barrel.
16. The fletching of claim 15, wherein the sealing member is
non-removably coupled to the attachment member.
17. The fletching of claim 15, wherein the sealing member is
removably attached to the attachment member such that during
flight, the sealing member is adapted to separate and fall off from
the attachment member by air resistance forces acting on the
sealing member.
18. The fletching of claim 15, wherein the sealing member is
substantially dome shaped.
19. The fletching of claim 15, wherein the sealing member has a
substantially round outer perimeter.
20. The fletching of claim 15, wherein an outer perimeter of the
sealing member has a diameter that is a predetermined distance less
than the inner diameter of the barrel so that a selected portion of
the compressed gas may pass by the outer perimeter of the sealing
member during use.
21. The fletching of claim 15, further including a plurality of
fins coupled to the elongate body, wherein the plurality of fins
are helically disposed upon the elongate body so that the plurality
of fins cause the fletching to rotate about a center axis of the
fletching during flight.
22. A fletching adapted to be attached to a proximal end of an
arrow shaft to aid in propelling of the arrow shaft by compressed
gas out of a barrel of a gun, the fletching comprising: (a) an
elongate body adapted to be coupled to an arrow shaft; (b) a
plurality of fins extending outward from the elongate body to a
selected distance from a centerline of the elongate body; and (c)
wherein the elongate body has a sealing member for blocking gas
flow, the sealing member extending outward from the centerline to
at least the selected distance for blocking gas flow.
23. The fletching of claim 22, wherein the sealing member is
adapted to separate and fall off from the arrow shaft by air
resistance forces acting on the sealing member during flight of the
arrow shaft.
24. The fletching of claim 22, wherein the sealing member is
substantially dome shaped.
25. The fletching of claim 22, wherein the plurality of fins are
helically disposed upon the elongate body.
26. A fletching adapted to be attached to a proximal end of an
arrow shaft to aid in propelling of the arrow shaft by compressed
gas out of a barrel of a gun, the fletching comprising: (a) an
elongate body adapted to be coupled to an arrow shaft; and (b) a
sealing member attached to the elongate body for substantially
impeding gas flow past the sealing member when the fletching is
disposed in a barrel of a gun, the sealing member extending outward
from a centerline of the fletching to a diameter of about 1/2 an
inch or greater.
27. The fletching of claim 26, wherein the sealing member is
adapted to separate and fall off from the arrow shaft by air
resistance forces acting on the sealing member during flight of the
arrow shaft.
28. The fletching of claim 26, wherein the sealing member is
substantially dome shaped.
29. The fletching of claim 26, wherein the plurality of fins are
helically disposed upon the elongate body.
30. The fletching of claim 26, wherein the diameter of the
fletching is about {fraction (7/10)} of an inch or greater.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/536,761, filed Jan. 15, 2004, entitled Airbow,
the disclosure of which is hereby expressly incorporated by
reference, and priority from the filing date of which is hereby
claimed under 35 U.S.C. .sctn. 119(e).
FIELD OF THE INVENTION
[0002] The present invention generally relates to methods and
apparatuses for propelling arrows, and more particularly to methods
and apparatuses for propelling arrows using compressed gas.
BACKGROUND OF THE INVENTION
[0003] Compressed gas has been used to propel objects from a gun
since as early as 1886, when inventor Clarence Hamilton developed a
gun that would propel a BB by compressed gas from a barrel, which
would later become known worldwide as the DAISY BB gun. Since then,
compressed gas has been used to propel other objects from a gun,
such as harpoons, darts, and bolts. However, the ability to propel
a standard length arrow from a gun by compressed gas has hereto
eluded those skilled in the art. Thus, there exists a need for a
compressed gas gun able to project a standard length arrow.
[0004] Further, it has been found that in compressed gas guns using
compressed gas cartridges as the compressed gas source, that the
energy contained in the compressed gas is inefficiently transferred
to the object being propelled. Moreover, it has been found that
previously developed compressed gas guns expand the compressed gas
contained in the cartridge directly from the compressed gas
cartridge without first pre-expanding the compressed gas. Thus the
compressed gas must instantly expand from a minute volume in the
compressed gas cartridge to a large volume as the compressed gas is
released into the barrel to propel the object. It is found that
this large expansion in volume of the gas and the time it takes the
gas to travel from the compressed gas cartridge to the barrel
results in an inefficient transfer of energy from the compressed
gas to the object being propelled. Moreover, since the compressed
gas must expand instantly and travel, a gradually increasing
pressure front is exerted upon the object being propelled. Thus,
the object being propelled begins moving out of the barrel before
the maximum pressure exertable by the compressed gas from the
cartridge has a chance to act upon the object. This gradual
increase in pressure significantly reduces the amount of energy
able to be transferred to the object as the object is propelled
along the length of the barrel.
[0005] Moreover, in an ideal compressed gas gun, the object being
propelled is acted upon by the maximum pressure exertable by the
compressed gas in the cartridge for the entire length of the
barrel. In previously developed compressed gas guns, the object
being propelled sees only a gradually increasing pressure as the
objected being propelled travels the length of the barrel, thereby
resulting in a significant reduction in muzzle velocities and
kinetic energy transferred to the object. Thus, there exists a need
for a compressed gas gun able to exert a more instantaneous
pressure front upon the object being propelled to increase the
amount of energy imparted to the object being propelled.
[0006] Additionally, previously compressed gas guns fail to provide
a means for the user to ascertain whether the compressed gas gun is
charged with the compressed gas. Thus, injuries due to accidental
discharges of the compressed gas and accidental firings are a
problem. Thus, there exists a need for a compressed gas gun that
indicates to the user whether or not the compressed gas gun is
charged.
SUMMARY OF THE INVENTION
[0007] One embodiment of a gun formed in accordance with the
present invention for using compressed gas from a compressed gas
cartridge to propel an arrow is disclosed. The gun includes a
barrel for receiving the arrow and a compressed gas storage
chamber. The compressed gas storage chamber is adapted to receive
and store compressed gas in an expanded state from the compressed
gas cartridge for later release. The gun also includes a valve
assembly for selectively releasing the compressed gas stored in the
compressed gas storage chamber within the barrel for propelling the
arrow out the barrel.
[0008] An alternate embodiment of a gun formed in accordance with
the present invention for using compressed gas to propel a standard
length arrow is disclosed. The gun includes a barrel of a length
about 22 inches or greater for receiving a standard length arrow
within the barrel and a valve assembly. The valve assembly is used
for selectively releasing a compressed gas from a compressed gas
source into the barrel for propelling the standard length arrow out
of the barrel.
[0009] One embodiment of a method performed in accordance with the
present invention for propelling an arrow from a gun having a
barrel, a trigger, and a compressed gas storage chamber is
disclosed. The method includes placing an arrow in the barrel,
discharging a compressed gas into the compressed gas storage
chamber for storage therein, and activating the trigger to cause
the compressed gas to be released from the compressed gas storage
chamber into the barrel to cause the arrow to be propelled from the
barrel.
[0010] One embodiment of a fletching formed in accordance with the
present invention for attaching to a proximal end of an arrow shaft
is disclosed. The fletching aids in the propelling of the arrow
shaft by compressed gas out of a barrel having an inner diameter
defined by an inner surface of the barrel. The fletching includes
an attachment member adapted to couple the fletching to a proximal
end of an arrow shaft and an elongate body. The elongate body is
coupled to the attachment member and has a sealing member. The
sealing member has an outer diameter substantially equal to the
inner diameter of the barrel such that the sealing member impedes
at least a substantial portion of the compressed gas from flowing
past the sealing member when the sealing member is in the
barrel.
[0011] An alternate embodiment of a fletching adapted to be
attached to a proximal end of an arrow shaft to aid in propelling
the arrow shaft by compressed gas out of a barrel of a gun is
disclosed. The fletching includes an elongate body adapted to be
coupled to an arrow shaft and a plurality of fins. The fins extend
outward from the elongate body to a selected distance from a
centerline of the elongate body. The elongate body has a sealing
member for blocking gas flow, the sealing member extending outward
from the centerline to at least the selected distance for blocking
gas flow.
[0012] Another embodiment of a fletching adapted to be attached to
a proximal end of an arrow shaft to aid in propelling the arrow
shaft by compressed gas out of a barrel of a gun is disclosed. The
fletching includes an elongate body adapted to be coupled to an
arrow shaft and a sealing member. The sealing member is attached to
the elongate body for substantially impeding gas flow past the
sealing member when the fletching is disposed in a barrel of a gun.
The sealing member extends outward from a centerline of the
fletching to a diameter of about 1/2 an inch or greater.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing aspects and many of the attendant advantages
of this invention will become better understood by reference to the
following detailed description, when taken in conjunction with the
accompanying drawings, wherein:
[0014] FIG. 1 is an elevation view of one embodiment of an arrow
gun formed in accordance with the present invention with a portion
of the arrow gun cut away to show some of the internal components
of the arrow gun;
[0015] FIG. 2 is a partial cross-sectional view of the arrow gun of
FIG. 1, the cross-sectional cut taken vertically through a
centerline of the arrow gun of FIG. 1 and a trigger shown prior to
being pulled;
[0016] FIG. 3 is a partial cross-sectional view of the arrow gun of
FIG. 1, the cross-sectional cut taken vertically through the
centerline of the arrow gun of FIG. 1 and the trigger shown after
being pulled;
[0017] FIG. 4 is partial perspective view of a portion of the arrow
gun shown in FIG. 2;
[0018] FIG. 5 is an elevation view of an aft portion of one
embodiment of an arrow formed in accordance with the present
invention;
[0019] FIG. 6 is a rear elevation view of the arrow shown in FIG.
5;
[0020] FIG. 7 is a cross-sectional view of the arrow of FIG. 5, the
cross-sectional cut taken substantially through section 7-7 of FIG.
5;
[0021] FIG. 8 is a partially exploded elevation view of an aft
portion of an alternate embodiment of an arrow formed in accordance
with the present invention;
[0022] FIG. 9 is a rear elevation view of the arrow shown in FIG.
8;
[0023] FIG. 10 is a cross-sectional view of the arrow of FIG. 8,
the cross-sectional cut taken substantially through section 10-10
of FIG. 8;
[0024] FIG. 11 is a partial cross-sectional view of an alternate
embodiment of an arrow gun formed in accordance with the present
invention, the cross-sectional cut taken vertically through a
centerline of the arrow gun and showing a trigger prior to being
pulled; and
[0025] FIG. 12 is a partial cross-sectional view of the arrow gun
of FIG. 11, the cross-sectional cut taken vertically through the
centerline of the arrow gun and showing the trigger after being
pulled.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] One embodiment of an arrow gun 100 formed in accordance with
the present invention is depicted in FIG. 1. The arrow gun 100 uses
a compressed gas to propel a standard length arrow 102 from a
barrel 104 of the arrow gun 100. Preferably, the compressed gas is
provided by a compressed gas cartridge 106, such as a well known
CO.sub.2 cartridge. The compressed gas cartridge 106 is received
within a cartridge receiver 108 which is used in coupling the
compressed gas cartridge 106 to a stock 110 of the arrow gun 100
and insulates the user from the freezing of the compressed gas
cartridge 106 upon release of the compressed gas contained therein.
The arrow gun 100 of the illustrated embodiment includes a scope
112, however a user may remove the scope and use a set of iron
sights 114 of the arrow gun 100 if they so choose. The arrow gun
100 further includes a trigger 116, a trigger guard 118, and a
safety 120. The arrow gun 100 is preferably used for propelling
"standard length" arrows, which in accordance with the current use
of the term in the trade, is an arrow having a length between about
23 inches to about 32 inches. Standard length arrows are
distinguishable from bolts, which are sometimes referred to as
arrows, but which have lengths of less than about 20 inches,
typically around 16 to 18 inches, and are often used with
crossbows.
[0027] Referring to FIG. 2, the components of the arrow gun 100
will be described in greater detail. The arrow gun 100 includes a
compressed gas storage chamber 122. The compressed gas storage
chamber 122 is preferably substantially disposed within the stock
of the arrow gun 100, however it should be apparent to those
skilled in the art that the compressed gas storage chamber 122 may
have a substantial portion extending outward of the stock. The
compressed gas storage chamber 122 includes a connector 124 having
male threads and a lance 125 for puncturing the gas cartridge 106.
The male threads on the connector 124 are sized and configured to
interface with female threads disposed on the receiver 108 to
permit the receiver 108 to removably couple to the connector 124
and press the compressed gas cartridge 106 upon the lance 125 to
release the compressed gas into the compressed gas storage chamber
122. Of note, once the compressed gas cartridge 106 is punctured by
the lance, the compressed gas cartridge 106 becomes an extension of
the compressed gas storage chamber 122. Although the connector 124
is illustrated and described as being adapted to accept threadless
compressed gas cartridges 106, it should be apparent to those
skilled in the art that the connector 124 may alternately be
designed to accept compressed gas cartridges 106 having
threads.
[0028] The volume of the compressed gas storage chamber 122, prior
to coupling of the compressed gas cartridge, is preferably greater
than the volume of the compressed gas cartridge 106. In one
embodiment, the volume of the compressed gas storage chamber 122,
once the compressed gas cartridge 106 is punctured and becomes part
of the compressed gas storage chamber 122, is at least double of
that of the compressed gas cartridge 106. In other embodiments, the
volume of the compressed gas storage chamber 122, once the
compressed gas cartridge 106 is punctured, is between about two to
twelve times that of the compressed gas cartridge 106. In another
embodiment, the volume of the compressed gas storage chamber 122,
once the compressed gas cartridge 106 is punctured, is between
about five to nine times that of the compressed gas cartridge 106
with a preferred value of about seven times that of the compressed
gas cartridge 106.
[0029] In one embodiment, the volume of the compressed gas storage
chamber 122 is selected to result in about a 20% to 80% decrease in
the pressure of the compressed gas contained in the compressed gas
cartridge 106 once released into the compressed gas storage chamber
122. In another embodiment, the volume of the compressed gas
storage chamber 122 is selected to result in about a 30% to 50%
decrease in the pressure of the compressed gas contained in the
compressed gas cartridge 106 once released into the compressed gas
storage chamber 122, with a preferred value of about 40%.
[0030] The compressed gas storage chamber 122 includes a charge
indicator 126 in communication with the compressed gas storage
chamber, the charge indicator 126 having a raised position as shown
in FIG. 2 indicating a presence of the compressed gas in the
compressed gas storage chamber 122 and lowered position as shown in
FIG. 3 indicating an absence of the compressed gas in the
compressed gas storage chamber 122. The charge indicator 126
includes a poppet 125 biased to a retracted position by a biasing
member, one suitable example being a spring 127. The charge
indicator 126 is transitioned from the lowered position to the
raised position by a pressure exerted upon the poppet 125 by the
compressed gas in the compressed gas storage chamber 122 which
overcomes the biasing force applied by the spring 127. Conversely,
upon release of the compressed gas from the compressed gas storage
chamber 122, the charge indicator 126 automatically retracts to its
lowered position of FIG. 3 by the biasing force of the spring 127.
The charge indicator 126 thus indicates to a user when the
compressed gas storage chamber 122 is holding a charge and when the
arrow gun 100 is potentially able to fire an arrow 102 or release
compressed gas by both a tactile means, as the user can feel the
presence of the raised poppet 125, and also by visual means, as the
user can see the raised position of the poppet 125 of the charge
indicator 126.
[0031] The compressed gas storage chamber 122 includes an opening
128. The opening 128 is circular and/or cylindrical in shape and is
coupled in communication with the barrel 104 of the arrow gun 100.
The opening 128 permits the release of the compressed gas stored in
the compressed gas storage chamber 122 into the barrel 104 to
propel the arrow 102 from the barrel 104.
[0032] Referring to FIG. 4, the arrow gun 100 includes a valve
assembly 130. The valve assembly 130 includes a sealing member 132
adapted to sealingly engage the opening 128 in the compressed gas
storage chamber 122. The sealing member 132 is circular in shape
and includes a seal 134 for sealing against an inner surface of the
compressed gas storage chamber 122. The sealing member 132 in the
illustrated embodiment is a well known O-ring, however it should be
apparent to those skilled in the art that other seals are suitable
for use with and are within the spirit and scope of the present
invention.
[0033] The sealing member 132 is coupled to a cam 136. The cam 136
is rotatingly coupled to a pivot pin 138. The cam 136 is able to
rotate about the pivot pin 138 from a sealing position shown in
FIG. 4 in which the sealing member 132 sealingly engages the
opening 128 of the compressed gas storage chamber 122 and a release
position shown in FIG. 3 wherein the sealing member 132 is
displaced from the opening 128 such that the compressed gas stored
in the compressed gas storage chamber 122 is released into the
barrel 104 to propel the arrow 102 from the barrel 104. The cam 136
includes a catch 144 for "catching" a notch of the trigger 116 as
will be described in more detail below.
[0034] Returning to FIG. 4, the arrow gun 100 also includes a
trigger assembly 140. The trigger assembly 140 includes the trigger
116, the trigger guard 118, and the safety 120 mentioned above, and
a pivot pin 142 and a biasing member 146. The trigger 116 is
rotatingly coupled to the pivot pin 142. The trigger 116 may rotate
about the pivot pin 142 between a cocked position shown in FIG. 4
to a tripped or release position shown in FIG. 3. In the cocked
position, the catch 144 of the cam 136 engages a notch 148 on the
trigger 116, the notch 148 adapted to releasably engage the catch
144. The notch 148 includes a cam follower 150, which in the
illustrated embodiment is in the form of a roller, for following a
cam surface 151 of the cam 136. The biasing member 146, which in
the illustrated embodiment is a spring, biases the trigger 116 into
the cocked position of FIG. 4.
[0035] The safety 120 of the trigger assembly 140 may be depressed
by the user so as to engage the trigger 116, thereby preventing the
trigger 116 from rotating from the cocked position. Pulling out the
safety 120 permits the trigger 116 to be rotated from the cocked
position to the tripped position by the user applying finger
pressure to the trigger 116. Although one embodiment of a safety
120 is illustrated and described relative to the illustrated
embodiment, it should be apparent to those skilled in the art that
other embodiments are within the spirit and scope of the present
invention.
[0036] The arrow gun 100 further includes a receiver 152. The
receiver 152 couples the compressed gas storage chamber 122 to the
barrel 104 of the arrow gun 100 and is coupled to both the valve
assembly 130 and the trigger assembly 140. In the illustrated
embodiment, the receiver 152 is horizontally split, forming a lower
half 154 and an upper half 156 of the receiver 152 which are
removably coupled to one another to aid in the installation and
maintenance of the arrow gun 100.
[0037] Turning to FIGS. 5-7, this detailed description will now
focus upon one embodiment of a fletching 200 formed in accordance
with the present invention suitable for use with the arrow gun 100
described above. The fletching 200 is adapted to transfer the power
contained in the compressed gas to an arrow shaft 103 and to
stabilize the arrow 102 during flight. The fletching 200 is made
from a rigid or semi-rigid material, a few suitable examples being
plastic, metal, resin based materials, carbon fiber based
materials, etc.
[0038] Referring to FIG. 5, the fletching 200 includes an elongate
body 204 extending between a forward end 206 and an aft end 208.
Disposed at the forward end 206 of the fletching 200 is an
attachment member 210 adapted to couple the fletching 200 to the
arrow shaft 103. In the illustrated embodiment, the attachment
member 210 is a post which is secured within a bore of the arrow
shaft 103 by a suitable means or combination of means, such as by
an interference fit, adhesives, mechanical fasteners, etc.
[0039] The elongate body 204 flares outward in a bell shape from
the forward end 206 to the aft end 208 of the elongate body 204 to
form a sealing member 202 at the aft end 208 of the fletching 200.
The sealing member 202 is adapted to have an outer diameter which
is substantially equal to an inner diameter of the barrel of the
arrow gun such that the sealing member 202 substantially seals the
barrel. In one embodiment, the sealing member 202 has an outer
diameter which is slightly less than the inner diameter of the
barrel such that the sealing member 202 may slide along the barrel
with minimal friction losses and so that a small amount of the
compressed gas may slip past the sealing member 202 to provide an
air cushion for the arrow to ride upon within the barrel during
shooting of the arrow. In one embodiment, the inner diameter of the
barrel is more than about 0.005 of an inch greater than the outer
diameter of the sealing member 202. In another embodiment, the
inner diameter of the barrel is more than about 0.010 of an inch
greater than the outer diameter of the sealing member 202. In a
preferred embodiment, the inner diameter of the barrel is more than
about 0.012 of an inch greater than the outer diameter of the
sealing member 202.
[0040] In another embodiment, the sealing member extends radially
outward from a centerline of the fletching 200 a selected distance.
For instance, the sealing member may extend outward from the
centerline to have a diameter greater than about a 1/2 inch,
greater than about {fraction (6/10)} of inch, or greater than about
{fraction (7/10)} of inch. In another embodiment, the sealing
member extends outward from the centerline to extend at least as
far outward from the centerline as a set of fins 212 disposed on
the elongate body 204. In other words, the fins 212 preferably do
not extend substantially radially outward past the outer perimeter
of the sealing member 202. Preferably, the sealing member 202 has a
circular outer perimeter and prevents gases from flowing past the
sealing member 202 inward of the sealing member's outer
perimeter.
[0041] Referring to FIGS. 5 and 7, extending radially outward at 90
degree intervals from the elongate body 204 are four fins 212,
although it should be apparent to those skilled in the art that
other arrangements and numbers of fins are within the spirit and
scope of the present invention. The fins 212 help to stabilize the
arrow 102 during flight. Preferably the fins 212 are disposed in a
helical pattern upon the outer surface of the elongate body 204 so
that the fins 212 are inclined slightly relative to a longitudinal
axis 216 of the fletching 200 to impart rotation of the arrow
during flight.
[0042] More specifically and as best shown in FIG. 5, a
longitudinal axis 218 of each of the fins 212 is inclined relative
to the longitudinal axis 216 of the fletching 200 by a
predetermined angle 220 as the fins wrap around the elongate body
204. In the illustrated embodiment, the fins 212 are inclined
relative to the longitudinal axis 216 of the fletching 200 by an
angle 220 selected to result in the arrow 102 rotating about its
longitudinal axis during flight a selected rate, such as one
revolution per 30 inches of travel. In one embodiment, the fins 212
are included relative to the longitudinal axis 216 by an angle
greater than 0 degrees but less than 10 degrees. In another
embodiment, the fins 212 are angled between greater than 0 degrees
and less than 5 degrees. In another embodiment, the fins 212 are
angled between greater than 0 degrees and less than 3 degrees.
Although a specific rate of rotation and angle of the fins is
illustrated and described, it should be apparent to those skilled
in the art that alternate rates and angles, either higher or lower
than described above, are within the spirit and scope of the
present invention.
[0043] Referring to FIG. 6, extending radial inward at 90-degree
intervals from the elongate body 204 at its aft end 208 are four
strengthening webs 214. The four strengthening webs 214 are coupled
to a securing member 217 disposed along a longitudinal center line
of the fletching 200. Turning to FIG. 5, the securing member 217 is
adapted to interface with an arrow holding assembly 160 coupled to
the receiver for interfacing with the securing member 217 to hold
the arrow 102 within the barrel even should the barrel be inclined
downward such that gravity acts on the arrow shaft 103 to draw the
arrow from the barrel. The securing member 217 may receive an
O-ring 162 of the arrow holding assembly 160 upon the outer
cylindrical surface of the securing member 217, such as illustrated
in FIG. 5. Alternately, the securing member 217 may receive an
O-ring within the securing member 217 such that the O-ring grips an
inner cylindrical surface of the securing member 217 to hold the
arrow 102 within the barrel until propelled therefrom by compressed
gas as shown with regard to the alternate embodiment of a fletching
300 and arrow holding assembly 488 shown in FIG. 8 and as will be
described in more detail below.
[0044] Turing to FIGS. 8-10, this detailed description will now
focus upon an alternate embodiment of a fletching 300 formed in
accordance with the present invention suitable for use with the
arrow gun described above. The fletching 300 includes an elongate
body 304 extending between a forward end 306 and an aft end 308.
Disposed at the forward end 306 of the fletching 300 is an
attachment member 310 adapted to couple the fletching 300 to an
arrow shaft 103. In the illustrated embodiment, the attachment
member 310 is a post which is secured within a bore of the arrow
shaft 103 by a suitable means or combination of means, such as by
an interference fit, adhesives, mechanical fasteners, etc.
[0045] The elongate body 304 is substantially cylindrical in shape.
A sealing member 302 is removably secured to the aft end 308 of the
fletching 300 by a sealing member retaining assembly 328. In the
illustrated embodiment, the retaining assembly 328 includes a
female receptacle 324 disposed in the aft end 308 of the elongate
body 304 for removably receiving a cooperatively shaped male
connector 326 of the retaining assembly 328 disposed on the sealing
member 302. The female receptacle 324 and the male connector 326
are adapted to cooperatively interact with one another to lightly
hold the sealing member 302 to the elongate body 304 such that even
if the barrel is inclined downward, such that gravity acts on the
arrow 102 to pull the arrow from the barrel, the elongate body 304
will remain attached to the sealing member 302. However, once the
arrow 102 leaves the barrel, air resistance acting upon the sealing
member 302 separates the sealing member 302 from the elongate body
304. Although the female receptacle 324 is shown disposed on the
elongate body 304 and the male connector 326 is shown disposed on
the sealing member 302, it should be apparent to those skilled in
the art that the female receptacle 324 may alternately be located
on the sealing member 302 and the male connector located on the
elongate body 304.
[0046] As best shown in FIG. 9, the sealing member 302 is adapted
to have an outer diameter which is substantially equal to an inner
diameter of the barrel of the arrow gun such that the sealing
member 302 substantially seals the barrel. In one embodiment, the
sealing member 302 has an outer diameter which is slightly less
than the inner diameter of the barrel such that the sealing member
302 may slide along the barrel with minimal friction losses and so
that a small amount of the compressed gas may slip past the sealing
member 302 to provide an air cushion for the arrow to ride upon
within the barrel during shooting of the arrow. In one embodiment,
the inner diameter of the barrel is more than about 0.005 of an
inch greater than the outer diameter of the sealing member 302. In
another embodiment, the inner diameter of the barrel is more than
about 0.010 of an inch greater than the outer diameter of the
sealing member 302. In a preferred embodiment, the inner diameter
of the barrel is more than about 0.012 of an inch greater than the
outer diameter of the sealing member 302.
[0047] In another embodiment, the sealing member 302 extends
radially outward from a centerline of the fletching 300 a selected
distance. For instance, the sealing member may extend outward from
the centerline to have a diameter greater than about a 1/2 inch,
greater than about {fraction (6/10)} of inch, or greater than about
{fraction (7/10)} of inch. In another embodiment, the sealing
member extends outward from the centerline to extend at least as
far outward from the centerline of a set of fins 312 disposed on
the elongate body 304. Preferably, the sealing member 302 has a
circular outer perimeter and prevents gas flow from flowing past
the sealing member 302 inward of the sealing member's outer
perimeter.
[0048] Extending radially outward at 120 degree intervals from the
elongate body 304 are three fins 312, although it should be
apparent to those skilled in the art that other arrangements and
numbers of fins are within the spirit and scope of the present
invention. The fins 312 help to stabilize the arrow 102 during
flight. Preferably the fins 312 are disposed in a helical pattern
upon the outer surface of the elongate body 304 so that the fins
312 are inclined slightly relative to a longitudinal axis of the
fletching 300 to impart rotation of the arrow during flight as
described above for the embodiment of FIGS. 5-7. However, to
simplify the drawings, the fins 312 in this embodiment are shown in
a non-helical arrangement running parallel with a longitudinal axis
of the fletching 300.
[0049] As best shown in FIGS. 8 and 9, the sealing member 302 may
have a retention assembly 350 for interfacing with an arrow
retaining assembly to hold the arrow 102 in the barrel, as
similarly described for the fletching shown in FIGS. 5-7. The
retention assembly 350 includes a cylindrical shaped bore 352
disposed along a central axis of the sealing member 302. The
cylindrical shaped bore 352 is adapted to receive an O-ring 490 of
an arrow holding assembly 488. The O-ring is used to apply a
sufficient amount of friction against the bore 352 such that the
arrow 102 will be retained in the barrel even when the distal end
of the barrel is tilted down from a horizontal position. The
friction exerted against the bore 352, however, is preferably not
an excessive amount, such that the arrow 102 can be easily
disengaged from the arrow holding assembly 488 without a
significant loss of energy once the compressed gas is released from
the compressed gas storage chamber.
[0050] Referring to FIG. 2 and in light of the above description of
the structure of the arrow gun 100, the operation of the arrow gun
100 will now be described. First, the safety 120 is depressed
locking the trigger 116 in the cocked position. The compressed gas
cartridge 106 is placed within the cartridge receiver 108. The
cartridge receiver 108 is screwed into the connector 124, resulting
in the compressed gas stored in the compressed gas cartridge 106
being released into the compressed gas storage chamber 122. In one
working embodiment, the compressed gas cartridge 106 is a well
known 12 gram CO.sub.2 compressed gas cartridge containing the
CO.sub.2 at a pressure of approximately 800 psi. Once the CO.sub.2
is released into the compressed gas storage chamber 122, the
pressure of the compressed gas decreases to a pressure between
about 200 psi to 400 psi, with a preferred value of 300 psi, since
the volume of the compressed gas cartridge 106 is approximately 14%
of the volume of the compressed gas storage chamber 122. (As noted
above, the volume of the compressed gas storage chamber 122
includes the volume of the compressed gas cartridge 106 once the
compressed gas is released from the compressed gas cartridge 106.)
The pressure of the compressed gas upon the charge indicator 126
causes the charge indicator to transition from its lowered position
shown in FIG. 3 to its raised position shown in FIG. 2, thereby
indicating to the user that the compressed gas storage chamber 122
is charged with a compressed gas.
[0051] Releasing the compressed gas from the compressed gas
cartridge 106 into the compressed gas storage chamber 122 permits
the compressed gas to pre-expand prior to release into the barrel
104. It has been found that by allowing the compressed gas to
partly expand and settle before releasing into the barrel, a higher
average pressure is exerted upon the arrow 102 as the arrow travels
the length of the barrel, resulting in an increase of the transfer
of energy from the compressed gas to the arrow 102, resulting in
higher muzzle velocities, increased accuracy, increased distances,
and the arrow exiting the barrel 104 with an increased level of
kinetic energy resulting in increased damage to a target impacted
by the arrow 102.
[0052] Although the illustrated embodiment is described as using
compressed gases of a specific pressure, it should be apparent that
compressed gases of other pressures, either higher or lower, are
suitable for use with and are within the spirit and scope of the
present invention. Further, although a specific gas, namely
CO.sub.2, is mentioned, it should be apparent to those skilled in
the art that any number of compressed gases may be used, a few
suitable examples being air and nitrogen. Additionally, although
the illustrated and described embodiment is described as using
compressed gases stored in a compressed gas cartridge, it should be
apparent to those skilled in the art that the arrow gun 100 may use
any suitable compressed gas source, such as bulk sources, a few
suitable examples being compressed air obtained from an air
compressor or a portable pressure tank.
[0053] Referring to FIGS. 4 and 8, once the compressed gas is
released into the compressed gas storage chamber 122, the arrow 102
may be inserted into the barrel 104 with the fletching 300 located
aft and the point of the arrow 102 facing forward toward a tip of
the barrel 104. The fletching 300 is engaged with the arrow holding
assembly 488 to aid in holding the arrow 102 in the barrel 104 even
when the distal end of the barrel 104 is tilted down from a
horizontal position.
[0054] The arrow gun 100 is pointed in a safe direction and the
safety 120 pulled or pushed outward to the safety off position. The
user's finger then enters the finger guard 118 and engages the
trigger 116. When the user wishes to discharge the arrow 102 from
the arrow gun 100, the user pulls with steady pressure upon the
trigger 116 thereby overcoming the biasing pressure of the trigger
biasing member 146 and causing the trigger 116 to rotate about the
pivot pin 142. Rotation of the trigger 116 continues until the
notch 148 of the trigger 116 disengages from the catch 144 of the
cam 136. At this point, the pressure exerted by the compressed gas
in the compressed gas chamber 122 forces the rapid rotation of the
cam 136, and thus the rapid unseating of the sealing member 132
from the opening 128 of the compressed gas storage chamber 122. As
the cam 136 rotates, the cam follower 150 follows along the cam
surface 151 of the cam 136. Once the sealing member 132 is unseated
from the opening 128, the pre-expanded compressed gas acts upon the
fletching 300, propelling the arrow 102 from the barrel 104 at a
very high velocity and with a large amount of kinetic energy.
[0055] Due to the clearance between the outer perimeter of the
fletching 300 and the inner perimeter of the barrel 104, a small
amount of the compressed gas released into the barrel passes past
the fletching 300 through the clearance gap. The compressed air
passing through the clearance gap helps promote an air bed for
"floating" the fletching 300 along the length of the barrel 104
with only minimal friction losses.
[0056] Referring to FIGS. 11 and 12, this detailed description will
now focus on an alternate embodiment of an arrow gun 400 formed in
accordance with the present invention. The arrow gun 400 of FIGS.
11 and 12 is substantially similar to the arrow gun 100 of FIGS.
1-4. Therefore, for the sake of brevity, this detailed description
will focus only upon where the alternate embodiment of FIGS. 11 and
12 differs from that of the embodiment of FIGS. 1-4.
[0057] The arrow gun 400 includes a compressed gas storage chamber
422 for storing a compressed gas substantially as described above.
However, the valve assembly 430 and trigger assembly 440 of the
arrow gun 400 for selectively releasing a compressed gas from the
storage chamber 422 differ from the valve assembly and trigger
assembly of the previously described embodiment.
[0058] The trigger assembly 400 includes a trigger 416 and a cam
436. When the trigger 416 is pulled, the trigger 416 rotates about
a pivot pin 442 thereby disengaging a notch 448 of the trigger 416
from a catch 444 of the cam 436, thereby permitting the cam 436 to
rotate clockwise from a cocked position shown in FIG. 11 to a
release position shown in FIG. 12. The cam 436 includes a second
catch 472 for engaging and holding a piston 474 of the valve
assembly 430 in a sealing position as will be described in greater
detail below.
[0059] The valve assembly 430 includes a piston assembly 470 and a
piston guide assembly 476. The piston assembly 470 includes a
sealing member comprised of a dome shaped piston 474 and a seal
478. The piston 474 and seal 478 sealing engage an opening 428 in
the compressed gas storage chamber 422. A stem 480 is coupled to
the piston 474 and a biasing member 482, one suitable example being
a spring, is disposed about the stem for biasing the piston 474 in
sealing engagement with the opening 428.
[0060] The stem 480 is received by the piston guide assembly 476.
Moreover, the piston guide assembly 476 includes an elongate bore
484 disposed within a guide body 486. The elongate bore 484 is
sized and configured to slidingly receive the stem 480 of the
piston assembly 470. The stem 480 may slide within the bore 484
between an extended position shown in FIG. 11, wherein the biasing
member 482 presses the piston 474 against the opening 428 in the
compressed gas storage chamber 422 and a retracted position shown
in FIG. 12, wherein the piston 474 is displaced from the opening
428 such that a compressed gas stored in the compressed gas storage
chamber 422 may be released to propel a standard length arrow from
the arrow gun 400.
[0061] When the trigger assembly 440 is in the cocked position
shown in FIG. 11, the second notch 472 of the cam 436 engages a
distal end of the stem 480, thereby retaining the piston 474
against the opening 428 of the compressed gas storage chamber 422.
When the trigger assembly 440 is in the release position shown in
FIG. 12, the cam 436 has rotated such that the biasing member 482
is overcome by the pressure of the compressed gas acting on the
piston 474 and the piston 474 is displaced from the opening 428 as
the stem 480 slides within the bore 484, moving the piston 474 to
its retracted position. When the pressure is released from the
compressed gas storage chamber 422, the biasing member 482 drives
the piston 474 backs to its extended position where the piston 474
is in sealing engagement with the opening 428 of the compressed gas
storage chamber 422 as shown in FIG. 11. Likewise, the cam 436 is
biased to rotate back to its cocked position such that the second
notch 472 of the cam 436 engages the distal end of the stem 480,
holding the piston 474 in sealing engagement with the opening
428.
[0062] Referring to FIG. 12, the piston guide assembly 476 includes
an arrow holding assembly 488 coupled to a forward end of the
elongate guide body 486. The arrow holding assembly 488 includes an
O-ring 490 sized and configured to be received within the securing
member 217 of the fletching 200 of FIGS. 5 and 6 or within the
securing member 352 of the fletching 300 of FIGS. 8 and 9. The
O-ring 490 is used to apply a sufficient amount of friction against
the securing member such that the arrow will be retained in the
barrel even when the distal end of the barrel is tilted down from a
horizontal position. The O-ring 490 is selected so that it does not
apply an excessive amount of friction against the securing member,
such that the arrow can be disengaged from the arrow holding
assembly 488 without a significant loss of energy once the
compressed gas is released from the compressed gas storage chamber
422.
[0063] While the preferred embodiment of the invention has been
illustrated and described, it will be appreciated that various
changes can be made therein without departing from the spirit and
scope of the invention.
* * * * *