U.S. patent application number 11/147769 was filed with the patent office on 2006-12-14 for clad surface arrow construction.
Invention is credited to John N. Young.
Application Number | 20060281593 11/147769 |
Document ID | / |
Family ID | 37524770 |
Filed Date | 2006-12-14 |
United States Patent
Application |
20060281593 |
Kind Code |
A1 |
Young; John N. |
December 14, 2006 |
Clad surface arrow construction
Abstract
A shaft construction comprising a forming tool manufactured by
known means to which is clad an exoskeleton comprising a
substantial portion of the shafts strength and other visual and
mechanical characteristics.
Inventors: |
Young; John N.; (Fairfax,
CA) |
Correspondence
Address: |
PACIFIC PRODUCTS
31 PAMARON WAY
STE. D
NOVATO
CA
94949
US
|
Family ID: |
37524770 |
Appl. No.: |
11/147769 |
Filed: |
June 9, 2005 |
Current U.S.
Class: |
473/578 |
Current CPC
Class: |
A63B 60/06 20151001;
A01K 87/00 20130101; A63B 53/10 20130101; A63B 60/16 20151001; A63B
60/08 20151001; A63B 49/02 20130101; F42B 6/04 20130101; A63B
2209/02 20130101; A63B 49/10 20130101; A63B 2209/023 20130101; A63B
60/10 20151001 |
Class at
Publication: |
473/578 |
International
Class: |
A63B 65/02 20060101
A63B065/02 |
Claims
1. A shaft construction comprising: an integral forming tool; an
exoskeleton of substantially rigid material clad to the surface of
the forming tool; an exoskeleton providing a substantial portion of
the total shaft strength.
2. The shaft of claim 1 in which the forming tool may include
features such as ribs, holes threads, splines, logos, bulges,
indents or the like.
3. The shaft of claim 2 which after cladding includes the possible
features as unitary parts of the finished shaft.
4. The shaft of claim 1 in which the forming tool comprises a
substantially hollow tubular shape.
5. The shaft of claim 4 in which cladding forms an exoskeleton over
portions of either or both the outer surface and the inner surface
of the forming tool.
6. The shaft of claim 4 in which the inside bore of the hollow
tubular shape may include features such as ribs, threads, splines,
bulges, indents, holes or the like
7. The shaft of claim 6 which after cladding includes the possible
inside features as unitary parts of the finished shaft.
8. The shaft of claim 1 in which the thickness of the exoskeleton
is controllably varied to give different but chosen wall
thicknesses at different locations of the shaft.
9. A method of shaft manufacture comprising: producing a forming
tool using known manufacturing techniques; cladding the forming
tool to produce a high strength exoskeleton using known cladding
methods; cladding the forming tool such that the resultant
exoskeleton forms a substantial portion of the final shaft strength
and other physical characteristics.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The following references are considered relevant prior art.
[0002] U.S. Pat. No. 6,866,599 B2 [0003] U.S. Pat. No. 6,821,219 B2
[0004] U.S. Pat. No. 6,595,880 B2 [0005] U.S. Pat. No. 6,554,726 B2
[0006] U.S. Pat. No. 6,554,725 B1 [0007] U.S. Pat. No. 6,520,876 B1
[0008] U.S. Pat. No. 6,179,736 B1 [0009] U.S. Pat. No. 6,129,642
[0010] U.S. Pat. No. 6,027,421 [0011] U.S. Pat. No. 6,017,284
[0012] U.S. Pat. No. 5,534,203 [0013] U.S. Pat. No. 5,273,293
[0014] U.S. Pat. No. 5,234,220 [0015] U.S. Pat. No. 4,422,259
[0016] U.S. Pat. No. 4,178,713 [0017] U.S. Pat. No. 4,061,806
[0018] U.S. Pat. No. 3,466,783 [0019] U.S. Pat. No. 3,003,275
[0020] U.S. Pat. No. 2,334,646 [0021] 386,320
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0022] Not applicable
REFERENCE TO SEQUENCE LISTING, TABLE, OR DISK APPENDIX
[0023] Not applicable
BACKGROUND OF THE INVENTION
[0024] Shafts used in the construction of arrows for archery have
undergone substantial technological development starting from the
historical known construction using solid wooden stakes to
light-weight, extruded metal tubes to present composite, tubular,
roll-wrapped construction. Each newly developed construction method
included new advantages and restrictions caused by the constraints
of each new technology. The shafts of the present invention teach a
unique wall construction designed to overcome restrictions of
previous teachings and a construction method designed to simplify
the manufacturing process of high-strength shafts.
[0025] It is therefore a purpose of the invention to teach a
simplified method of producing arrow shafts, while another purpose
of the invention is to produce unitary shafts with functionality
that required expensive assembly of several components in previous
shaft construction techniques. A further purpose of the invention
is to teach unitary shaft design with function possibilities not
easily available with earlier construction methods.
[0026] While the teachings of this invention are primarily
described for the construction of arrow shafts, it will be obvious
to those with knowledge of the art that the design and construction
method taught may apply with equal advantage to a wide range of
substantially long and narrow products.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a cross sectioned view of existing arrow
construction
[0028] FIG. 2 is a cross sectioned view of a portion of the arrow
shaft shown in FIG. 1.
[0029] FIG. 3 is a diagram of the known process required to make a
roll-wrapped shaft
[0030] FIG. 4 is a diagram of the process required to make the
shaft of the invention.
[0031] FIG. 5 is a sectioned view of a portion of a shaft of the
invention
[0032] FIG. 6 is a sectioned view of the tip portion of the arrow
of the invention
DETAILED DESCRIPTION OF THE INVENTION
[0033] Modern tubular arrow shafts are generally produced using two
main methods of manufacture. These methods are (1) extruding metal
into shafts, typically using an aluminum alloy for the extruded
metal, and (2) roll-wrapping shafts typically using carbon
composite fabric or other sheet material as the rolled substance.
There is also a combination of these two main methods sometimes
used to make shafts in which fabric material is rolled over and
bonded to an extruded aluminum shaft to make a unitary shaft
construction.
[0034] Metal shafts are typically extruded of a single alloy and
rely almost exclusively on the chemical and mechanical
characteristics of the metal alloy to determine the strength, flex
and other characteristics of the finished shaft. Because the metal
shafts are extruded, the shape considerations of the shafts are
understood to be the same as those applied to all extruded
products. The metals chosen to extrude shafts are typically
expensive alloys, but the extrusion process is well known and
generally lends itself to known automated manufacturing
processes.
[0035] Because they have a number of layers, roll-wrapped shafts
can have their characteristics adjusted by selecting different
fabric materials and deciding the order of materials as they are
layered or wrapped around a substantially bar-shaped forming tool
called a mandrel. Further, the shape and dimensional cuts of fabric
patterns can be adjusted to produce special shaft
characteristics.
[0036] Producing shafts by wrapping and bonding fabric over
extruded metal shafts can combine the benefits and final shaft
characteristics of both methods but tends to be very costly since
the expenses of both systems must be added together.
[0037] The arrow of FIG. 1 shows known construction Arrow Shaft 3
to which Vanes 2 and internally-threaded Insert 4 are affixed. Nock
1 is frictionally gripped in the Arrow Shaft and Point 5 is
threadably retained in the Insert. While extruded metal shafts have
a single-layer wall section, roll wrapped shafts have a
mulitiplicity of Wall Layers 6 as shown in FIG. 2. The number of
layers, the composition of the layers, the thickness of the layers
and the order of the layers are all chosen to produce the desired
characteristics of the final shaft.
[0038] In known methods of producing arrow shafts, forming tools
are required to produce the shape of the shafts, and the forming
tools, while essential to the formation of the shafts, are removed
during the production process and are not a part of the finished
product. The forming tool for extruded metal shafts is typically a
hardened-metal bushing through which metal is forced under very
high pressure to form a continuous metal tube which is then cut to
length to become the final shaft.
[0039] The forming tool for roll wrapped shafts is typically a bar
of hardened steel named a mandrel which is shaped to establish the
inside diameter and shape of the arrow shaft. Cut fabric patterns
of a chosen material are wrapped around the mandrel by a known
rolling method and then processed into the finished arrow shaft,
during which process, the mandrel is removed and recycled to be
used again for another shaft. The roll wrapping method involves a
substantial number of steps and a large amount of labor and time
and is illustrated in FIG. 3. Since the roll wrapping process is
known, it is described only briefly as follows.
[0040] Specialized fabric usually comprising a matrix of
high-strength fibers and thermoset resin is cut into patterns that
are roll-wrapped around solid steel mandrels.
[0041] A polymer tape is spiral-wrapped over the wrapped fabric to
both hold the fabric in place and to squeeze the fabric into tight
compaction.
[0042] The assembly of mandrel, fabric and tape is baked in an oven
for a prescribed period of time during which the fiber/resin matrix
solidifies into a single-characteristic tube which forms the base
characteristics of the arrow shaft.
[0043] After baking, the mandrel is removed from the inside of the
shaft and recycled, following which the polymer tape is removed
from the outside of the shaft.
[0044] The shaft is sanded smooth, cut to length, cleaned and the
insert is fixed into one end of the tube. The shaft is then
processed for final assembly and packaging.
[0045] The shaft of the invention is produced in a much simplified
process using known processes and in which the Forming Tool remains
an integral part of the finished shaft. The forming tool of the
invention is clad with material that provides an Exoskeleton 8 as
shown in FIG. 5 and FIG. 6 that provides a substantial portion of
the strength of the final shaft.
[0046] The simplified process of the invention is illustrated in
FIG. 4 and is briefly described as follows:
[0047] Forming Tool 20 is precisely formed by known processes such
as injection molding, extrusion, machining or the like.
[0048] Forming Tool 20 is Clad 21 with an exoskeleton of
substantially rigid material by a choice of know processes such as
plating, dipping, physical vapor deposition or the like. The
desired final shaft characteristics determine which known cladding
process will be used and which material will be used to form the
Exoskeleton. Since known processes can precisely control the
cladding thickness, the Forming Tool 20 is dimensionally shaped so
that the cladding builds to the final dimension of the shaft, and
after cladding the shaft can go directly to Final Assembly and
Packaging 23.
[0049] While the invention proposes the use of known cladding
process to apply an Exoskeleton over a Forming Tool, it anticipates
the development of improved materials to be used in those known
processes so that improved Exoskeletons will develop as the
materials used in conventional cladding processes become
available.
[0050] Since the cladding process provides a substantial portion of
the final shaft strength, Forming Tool 20 has limited requirements
concerning strength and material content. Forming Tool 20 requires
primarily that its shape remain stable during all stages of
processing and that it be of a material compatible with proper
cladding of the Exoskeleton material.
[0051] FIG. 5 shows a sectioned view of a portion of Shaft 7
indicating Exoskeleton 8 clad over Forming Tool 9.
[0052] The liberty to shape the Forming Tool by conventional means
permits features to be included in the Forming Tool to reduce parts
assembly and to add features that might be difficult or
prohibitively expensive to include with existing production
methods. The sectioned view of FIG. 6 shows Forming Tool 9 shaped
to include Internal Thread Section 10 dimensioned so that after the
exoskeleton cladding there remains high strength threads to permit
threadable attachment of Point 5.
[0053] U.S. Pat. Nos. 6,179,736 B1 and 6,821,219 B2 teach a tapered
shaft construction.
[0054] U.S. Pat. No. 6,595,880 B2 teaches a method of fluting an
arrow shaft.
[0055] U.S. Pat. No. 6,129,642 teaches a grooved arrow shaft
[0056] U.S. Pat. No. 6,017,284 teaches a reduced diameter portion
arrow shaft.
[0057] U.S. Pat. No. 5,273,293 teaches a variety of fluted shapes
for arrow shafts.
[0058] All the taught features such as tapers, flutes, grooves,
varied diameters and the like can be far more easily formed with
the use of a Forming Tool and the rigid Exoskeleton structure of
the invention. Even logos and names can be shaped into the Forming
Tool to become integral features of the final shaft. Any shape into
which the Forming Die can be formed determines the basis of the
final Exoskeleton shape.
[0059] It is understood that known methods of controlling cladding
processes can also vary the thickness and therefore the
characteristics of the Exoskeleton even when using a standard
Forming Tool. For example the Exoskeleton thickness can be adjusted
during processing along the axial length of the shaft to produce
differing axial weight distribution or provide extra strength at
chosen shaft positions or other similar considerations.
[0060] While the description of the invention is directed at shaft
manufacture and specifically at arrow shaft construction, it will
be understood by those with knowledge of the art that the
techniques described may apply with equal advantage to a wide
variety of parts that share the common feature of a substantially
long, thin shape. Such a variety of parts may include but are not
restricted to fishing rods, golf shafts, helicopter blades, boat
propellers, oars, hockey sticks, tennis rackets, pool cues, ski
poles, boat tillers, bicycle parts, and control linkage for
motorcycles, automobiles, and aircraft.
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