Noise and recoil reducing bow stabilizer for archery bows

A bow stabilizer is mounted to an archery bow for the purpose of balancing the archery bow and reducing recoil, shock and vibration forces and noise that results when an arrow is discharged from the archery bow. The bow stabilizer has a hollow body which defines a chamber. An end plug is sealably secured to an end of the hollow body and another end plug is sealably secured to an opposite end of the hollow body. The bow stabilizer has at least one counterweight which is adjustable along a longitudinal axis of the hollow body to balance the archery bow. The chamber of the hollow body is partially filled with granular solids.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a bow stabilizer that is mounted to an 
archery bow. The bow stabilizer is attached to the archery bow for the 
purpose of balancing the archery bow and reducing recoil, shock, vibration 
and noise that results when an arrow is discharged from the archery bow 
2. Description of the Prior Art 
In recent years, various stabilizers and vibration dampeners have been 
developed to both balance and absorb the shock when an arrow is discharged 
from an archery bow. U.S. Pat. No. 4,570,608 teaches an archery bow 
stabilizer and vibration dampener that are mounted on an archery bow. As 
taught by the '608 patent, a hollow cylinder is filled with a viscous 
fluid, such as oil, to attenuate vibration when an arrow is discharged 
from the archery bow. An energy dissipating rod, located inside the hollow 
cylinder, is connected to a stud which screws into a riser of the archery 
bow. The energy dissipating rod is in direct contact with the viscous 
fluid. The stabilizer rod transfers energy to the viscous fluid when an 
arrow is discharged from the archery bow. One end of the hollow cylinder 
is permanently sealed to prevent the escape of the viscous fluid. The 
other end of the cylinder has a plug and rubber sealing ring which 
prevents the viscous fluid from escaping from the cylinder. A variety of 
external weights having different masses are threaded onto an end of the 
stabilizer to provide additional balancing for the archery bow. As taught 
by the '608 patent, the stabilizer is approximately 18 inches in length. 
However, field experimentation is necessary to adequately balance the 
archery bow. In order to balance the bow using this stabilizer, 
differently sized weights are attached to the end of the stabilizer until 
the archery bow is balanced. Thus, the hunter is required to have at his 
disposal a variety of additional weights to fine tune and properly adjust 
or balance the archery bow. One disadvantage is that the length required 
to absorb the energy and vibrations is too long to effectively permit 
hunting of game animals. Additionally, placing weights at the end of the 
stabilizer to balance the bow makes the stabilizer even longer and has an 
unattractive appearance. 
U.S. Pat. No. 4,779,602 teaches a rod or central cylindrical core that is 
threaded onto the forward side of an archery bow. The '602 patent teaches 
a sleeve that is slidable on the core and biased on the rear of the core 
by a stiff spring. When the bow string is released and an arrow is 
discharged, the sleeve slides forward by momentum to absorb the shock 
produced The sleeve, upon firing, moves forward and is then snapped back 
by a spring force which acts as a resilient shock absorber. The '602 
patent further teaches that a receptacle, located at the end of the core, 
is loaded with lead pellets or shot to balance the bow in the hand of the 
archer. Similar to the '608 patent the '602 patent has a disadvantage 
because it requires the hunter to carry additional weights, lead pellets 
or shot, to properly adjust the archery bow. Another disadvantage is that 
the length of the stabilizer is increased by locating the additional 
balancing weight at the end of the stabilizer. 
U.S. Pat. No. 4,615,327 teaches a two stage resiliently mounted stabilizer 
having a first and a second housing that are attached to an archery bow. 
The first housing is resiliently mounted to the archery bow. The second 
housing is resiliently mounted to an end of the first housing. The first 
housing has a first rubber tube which is inside the first housing. A flat 
resilient washer separates the two housings and a connecting member is 
used to connect and tighten the second and third rubber members. This 
allows the second housing to move with respect to the first housing. 
Additional weights may be connected to the end of the second housing. One 
disadvantage is that the characteristics and properties of rubber do not 
adequately solve the archer's needs in dampening vibrations and reducing 
noise when an arrow is discharged from the archery bow. Another 
disadvantage is that the stabilizer is generally too long to be used for 
hunting game animals. Another disadvantage is that weight added at the end 
of the stabilizer increases the length and adds too much weight to the 
archery bow, causing fatigue to the archer. Yet another disadvantage is 
that the stabilizer performance will change with a change in temperature 
as the fluid viscosity changes. Under hunting conditions, such change in 
stabilizer performance results in a decrease of bow accuracy. 
U.S. Pat. No. 4,660,538 teaches another stabilizer mounted to an archery 
bow. A spring is compressed by rotating a nut located at the end of the 
stabilizer. A weight may be added to the opposite end. The spring design 
of the '538 patent has a disadvantage because it provides insufficient 
stabilization. The length of the stabilizer is generally too long and 
hence impractical for use in hunting. 
SUMMARY OF THE INVENTION 
It is an object of this invention to provide a bow stabilizer that is short 
in length, lightweight and has a counterweight which does not add to the 
length of the bow stabilizer. 
It is another object of this invention to provide a bow stabilizer for 
archery bows that balances the archery bow and reduces the recoil, shock, 
vibration and noise that result when an arrow is discharged from the 
archery bow. 
It is another object of this invention to provide a bow stabilizer having a 
hollow body which defines a sealed chamber that is partially filled with 
granular solids. The bow stabilizer has mounting means for mounting itself 
to the archery bow. The chamber of the bow stabilizer is partially filled 
with granular solids. 
It is another object of this invention to provide a bow stabilizer having 
an elongated hollow body which defines a sealed chamber that is partially 
filled with granular solids. The bow stabilizer has at least one end plug 
for sealing and containing the granular solids within the chamber. The bow 
stabilizer has mounting means for mounting itself to the archery bow and a 
counterweight that is fixedly adjustable along a longitudinal axis of the 
elongated hollow body. 
It is a further object of this invention to provide a bow stabilizer that 
has a chamber partially filled with sand, crushed stone, plastic 
particles, metal particles, or any other suitable granular solids to 
absorb the energy of the archery bow when an arrow is discharged. 
It is yet another object of this invention to fill approximately 50 to 99 
percent of the sealed chamber with the granular solids. 
The above objects are achieved in the present invention with a bow 
stabilizer that is mounted to an archery bow. The bow stabilizer has a 
hollow body which defines a sealed chamber. In a preferred embodiment, the 
hollow body has an elongated shape. An end plug is sealably secured to an 
end of the elongated hollow body and an end plug is sealably secured to an 
opposite end of the hollow body. The bow stabilizer has mounting means for 
mounting itself to an archery bow. A counterweight is fixedly adjustable 
along a longitudinal axis of the elongated hollow body. The sealed chamber 
of the hollow body is partially filled with granular solids. 
The granular solids which partially fills the chamber may be sand, crushed 
stone, plastic particles, ceramic particles, metal particles and/or any 
other suitable granular solids. In a preferred embodiment, the granular 
solids has a generally average particle size. The size of the particles 
should be less than approximately 1/8 inch. Preferably, the size of the 
particles should be approximately 15-20 mils. These particles effectively 
absorb the shock and thus reduce recoil, vibration and noise that results 
when the arrow is discharged from the archery bow. By reducing the noise 
when an arrow is discharged from the archery bow, scaring game animals is 
virtually eliminated and thus allows the hunter to take a second shot, 
should the first shot miss the intended target. Thus, a hunter may be able 
to shoot multiple arrows at the targeted game animal. The benefits of this 
invention are equally great in marksmanship contests since recoil or 
"kick" is reduced, allowing the marksman to shoot with greater accuracy. 
It is an important aspect that the chamber is only partially filled with 
granular solids. The chamber is approximately 50 to 99 percent filled with 
the granular solids. In a preferred embodiment, the chamber is 
approximately 70 to 95 percent filled. By only partially filling the 
chamber of the hollow body, the movement of the granular solids particles 
is less restrictive and such movement allows the granular solids to 
effectively absorb the energy of the archery bow when an arrow is 
discharged. 
In a preferred embodiment, the mounting means comprise an end plug having a 
threaded shaft. Archery bows conforming to Archery Manufacturers 
Organization (AMO) standards have an internally threaded coupling 
positioned on a riser section. The threaded shaft of the end plug is 
secured within such internally threaded coupling. It is not critical how 
the bow stabilizer is mounted to the archery bow, so long as it is secured 
to the archery bow. In another embodiment, the mounting means comprise the 
end plug having a shaft which is press fitted into the internally threaded 
female coupling of the archery bow. In addition to the various methods of 
securing the bow stabilizer to the archery bow, sealing means for sealing 
the chamber may be interposed between the hollow body and the end plugs. 
Preferably, the sealing means comprise an O-ring or any other suitable 
design. The sealing means may be a rubber washer. A lock nut may also be 
threaded on the threaded shaft to lock the bow stabilizer with respect to 
the archery bow. 
In another preferred embodiment, the end plugs are sealably secured to ends 
of the hollow body. In this particular embodiment, the end plugs each have 
a cap portion. The cap portion of each end plug has a chamfered edge. A 
connecting portion of each end plug has a knurled surface. In one 
embodiment, the end plugs are secured to the hollow body by an 
interference fit or press fit. The end plugs can also be welded to the 
hollow body or secured to the hollow body by a threaded connection. If the 
end plugs are secured to the hollow body by a threaded connection, the 
connecting portion of each end plug will have a threaded shaft and the 
hollow body will have an internal female coupling mateable with each end 
plug. 
At least one counterweight is fixedly adjustable along a longitudinal axis 
of the hollow body. In a preferred embodiment, the counterweight is formed 
as a generally cylindrical collar. Positioning the counterweight along the 
longitudinal axis of the hollow body does not increase the length of the 
stabilizer. In addition to providing an aesthetic design, the overall 
compact design of the present invention allows an archer to carry the bow 
through dense woods and forests without catching the bow stabilizer on 
branches, shrubs, trees, and the like. Additionally, a bow stabilizer 
according to this invention is unaffected by the elements of nature. For 
example, the performance of the bow stabilizer is unaffected by extreme 
moisture and temperature conditions. The prior art teaches metal springs 
which will rust and rubber connections which will deteriorate over time. 
Additionally, the prior art teaching viscous fluids for dampening shock 
from the bow will have much different characteristics as the temperature 
changes and the viscosity of the liquid fluid changes. The present 
invention solves this problem and others. 
In another preferred embodiment of this invention, the counterweight is 
threaded onto the hollow body. In this embodiment, the hollow body has an 
externally threaded surface. The cylindrical counterweight has an 
internally threaded female coupling that mates with the externally 
threaded surface of the hollow body. By rotating the counterweight with 
respect to the hollow body, the counterweight moves along a longitudinal 
axis and the archery bow is balanced. More than one counterweight may be 
mounted along the longitudinal axis of the hollow body. The counterweight 
can also comprise a split ring. In another preferred embodiment, the 
counterweight has a set screw for preventing longitudinal movement of the 
counterweight with respect to the hollow body. The set screw can be used 
whether or not the hollow body has an externally threaded surface.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Over the past decades, archery bow hunting and archery marksmanship have 
become quite popular. Although today's modern archery bows are a vast 
improvement over earlier bows, there is still a great demand for an 
effective, reliable, economical archery bow stabilizer. Although some bow 
stabilizers have been introduced, none of them solve the needs of today's 
hunter and marksman. 
As shown in FIG. 1, this invention solves this need by providing bow 
stabilizer 16 that is mounted to archery bow 10. Bow stabilizer 16 has a 
hollow body 18 which defines sealed chamber 20. Chamber 20 is partially 
filled with granular solids 50. In one embodiment of this invention, 
granular solids 50 fills approximately 50 to approximately 99 percent of 
chamber 20, preferably approximately 70 to approximately 95 percent. 
As shown in FIG. 1, according to a preferred embodiment of this invention, 
archery bow 10 has internally threaded female coupling 14 for securing and 
mating bow stabilizer 16. Internally threaded female coupling 14 conforms 
to Archery Manufacturers Organization (AMO) standards. According to the 
AMO standards, the thread size of the female coupling is 5/16".times.24. 
As shown in FIG. 2, elongated hollow body 18 has end 22 and end 24. End 
plug 30 is sealably secured to end 22 and end plug 30 is sealably secured 
to end 24. At least one counterweight 40 is fixedly adjustable along a 
longitudinal axis of elongated hollow body 18. 
According to one preferred embodiment, granular solids 50 is sterilized 
sand that is free of foreign matter. The sand should be thoroughly dried 
before it is used to partially fill chamber 20. Preferably, the sand or 
other granular solids 50 comprise particles of generally average size. The 
term "average size" used throughout the specification and claims means 
that the shapes and diameters of particle sizes may vary, but that the 
individual particle shapes and diameters should not be grossly 
disproportionate to one another. The average size of particles of granular 
solids 50 is approximately less than about 1/8 of an inch. Preferably, the 
particle size is in the range of approximately 15 to 20 mils. In addition 
to sand, granular solids 50 may also comprise crushed stone, plastic 
particles, ceramic particles, metal particles, or any other suitable 
material that transfers energy through friction when the particles of 
granular solids 50 move against the inner wall of hollow body 18 and each 
other. Additionally, this invention is not limited to use of one 
particular type of granular solids 50. For example, chamber 20 may be 
partially filled with sand, plastic particles, and crushed stones. Sealing 
means (not shown) may be interposed between end plugs 30 and hollow body 
18. Sealing means may comprise a gasket or an O-ring or any other type of 
suitable material. A gasket, such as a rubber washer, will prevent very 
fine granular solids 50 from leaking from chamber 20. 
In a preferred embodiment, hollow body 18 is constructed of any suitable, 
lightweight, rigid material. For example, hollow body 18 may be 
constructed of a metal alloy, plastic, fiberglass, or the like. 
Preferably, the material selected for hollow body 18 is one which does not 
corrode or deteriorate over time. Although the shape of hollow body 18 is 
preferably elongated, as shown in FIGS. 1 and 2, hollow body 18 can have 
other suitable shapes. For example, hollow body 18 may have an overall 
tapered shape or it may be necked down in a mid region. Although hollow 
body 18 is preferably cylindrical, the cross-sectional shape is not 
critical and hollow body 18 may have various other suitable polygonal 
cross-sectional shapes, such as a rectangular or a triangular shape. In 
another preferred embodiment, two or more bow stabilizers 16 can be 
secured side-by-side to increase the internal surface area of hollow body 
18 and thus achieve increased energy absorption. 
It is preferred but not necessary for hollow body 18 to have two end plugs 
30. Hollow body 18 may be drilled so that only one end is open and hence 
either end plug 30 is required. Practically any method of sealably 
securing end plugs 30 to hollow body 18 will suffice. End plugs 30 can be 
either press fitted or welded to hollow body 18. 
In another preferred embodiment, end plugs 30 each have a cap portion 34. 
Cap portion 34 has a chamfered edge 35 to prevent any sharp edges. End 
plugs 30 each have a connecting portion 36 connected to cap portion 34. 
Preferably, connecting portion 36 has a peripheral knurled surface 37. 
Knurled surface 37 provides sufficient friction and interference fit to 
secure end plugs 30 to hollow body 18. With an interference fit, the 
diameter of connecting portion 36 is less than the diameter of cap portion 
34. In addition to knurled surface 37, any other type of treated or 
machined surface will suffice to sealably secure end plugs 30 to hollow 
body 18. 
In another preferred embodiment, each end plug 30 is secured to hollow body 
18 with a threaded connection. In this embodiment, each end plug 30 has an 
externally threaded shaft, not shown in FIGS. 1-3. Hollow body 18 has 
internally threaded female coupling 33, also not shown in FIGS. 1-3, 
located at ends 22 and 24 of hollow body 18. In this embodiment, the 
externally threaded shaft of each end plug 30 is mateable with the 
internally threaded female coupling of each end 22 and 24. 
It is also apparent that each end plug 30 can have an internally threaded 
female coupling 33, as shown in FIG. 2. Threaded shaft 31 is secured and 
mated with internally threaded female coupling 33. It is apparent that 
threaded shaft 31 can be secured to either end plug 30. Additionally, a 
conventional game tracker may be attached to one of end plug 30. 
In a preferred embodiment, threaded shaft 31 is mateable with internally 
threaded female coupling 14 located on front side 11 of archery bow 10. 
Although not necessary, as shown in FIG. 2, lock nut 39 may be threaded on 
threaded shaft 31 for additionally securing bow stabilizer 16 to archery 
bow 10. In one embodiment, mounting means for securing bow stabilizer 16 
to archery bow 10 comprise a shaft secured to one of end plugs 30 having a 
shaft which is press fitted into internally threaded female coupling 14 of 
archery bow 10. In this embodiment, the shaft is made of a soft material 
which does not damage the internal threads of internally threaded female 
coupling 14. 
In addition to suppressing noise and reducing recoil, shock and vibration, 
as shown in FIGS. 1 and 2, bow stabilizer 16 can have at least one 
counterweight 40 for balancing archery bow 10. Counterweight 40 is 
adjustable along a longitudinal axis 26 of hollow body 18. In one 
embodiment, counterweight 40 slides with respect to hollow body 18 along a 
longitudinal axis of elongated hollow body 18. Frictional forces prevent 
counterweight 40 from moving longitudinally once archery bow 10 is 
balanced. Counterweight 40 preferably has the form of a cylindrical 
collar. Counterweight 40 may also comprise a split ring configuration, 
which is not shown in the drawings. In a preferred embodiment, 
counterweight 40 has set screw threaded coupling 46 which accommodates a 
set screw for preventing longitudinal movement of counterweight 40 with 
respect to elongated hollow body 18, once archery bow 10 is balanced. The 
set screw, not shown in the drawings, has a wing nut or any other type of 
screw which does not require tools for field tightening or loosening. 
In another embodiment according to this invention, counterweight 40 has an 
internally threaded female coupling. In this embodiment, hollow body 18 
has an externally threaded surface which mates with the internally 
threaded female coupling. Archery bow 10 is balanced by conveniently 
rotating counterweight 40 with respect to hollow body 18. Hence, the need 
to carry additional weights is entirely eliminated. 
As shown in FIG. 1, bow stabilizer 16 is firmly secured to archery bow 10, 
preferably at front side 11 of the bow handle riser. Upon release of a 
bowstring and discharge of arrow 13, recoil and vibration forces are 
transferred through the bow limbs and into the bow handle riser. This 
vibration causes noise and loosening of accessories mounted on archery bow 
10. The vibrational energy is transferred to granular solids 50 which 
absorbs the energy as the particles of granular solids 50 collide with one 
another and the inner wall surface of hollow body 18. 
To further reduce and dissipate the recoil, shock and vibration forces and 
noise that results when arrow 13 is discharged from archery bow 10, hollow 
body 18 can have internal baffle means for increased surface area against 
which the particles of granular solids 50 collide. According to a 
preferred embodiment as shown in FIG. 3, hollow body 18 has an inner body 
wall 60 with projecting ribs 62. In this embodiment, ribs 62 extend along 
the length of chamber 20, preferably parallel to the longitudinal axis of 
hollow body 18. The design configuration of ribs 62 is not critical so 
long as the configuration provides a suitable shape for causing the 
individual particles of granular solids 50 to further collide with one 
another and inner body wall 60. 
Accordingly, it is appreciated that the disclosed preferred embodiments 
accomplish the objects of this invention. Obviously, many modifications 
and variations of this invention are possible, in light of the above 
teachings. It is therefore understood that, within the scope of the 
appended claims, the invention may be practiced otherwise as specifically 
described and can be varied considerably without departing from the basic 
principles of the invention.