U.S. patent application number 09/978873 was filed with the patent office on 2003-01-16 for arrow shaft and method for manufacturing the same.
Invention is credited to Song, Jumsik.
Application Number | 20030013565 09/978873 |
Document ID | / |
Family ID | 19711978 |
Filed Date | 2003-01-16 |
United States Patent
Application |
20030013565 |
Kind Code |
A1 |
Song, Jumsik |
January 16, 2003 |
Arrow shaft and method for manufacturing the same
Abstract
An arrow shaft composed of a non-elastic fiber and a low elastic
fiber and a method for manufacturing the same are disclosed. The
method comprises the steps of spreading an elastic sheet such as
pre-impregnated or prepreged carbon or glass fiber, adhering a
non-elastic or low elastic fiber, preferably a prepreged
pre-impregnated natural, synthetic, or glass fiber onto the elastic
sheet, winding them onto a mandrel, and carrying out tapping, heat
treating/cooling, releasing, and polishing processes.
Inventors: |
Song, Jumsik; (Pusan,
KR) |
Correspondence
Address: |
NOTARO & MICHALOS P.C.
Empire State Building
350 Fifth Avenue, Suite 6902
New York
NY
10118-0110
US
|
Family ID: |
19711978 |
Appl. No.: |
09/978873 |
Filed: |
October 16, 2001 |
Current U.S.
Class: |
473/578 ;
156/187 |
Current CPC
Class: |
F42B 6/04 20130101 |
Class at
Publication: |
473/578 ;
156/187 |
International
Class: |
F42B 006/04; B65H
081/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2001 |
KR |
2001-41059 |
Claims
What is claimed is:
1. A method of manufacturing an arrow shaft by layering and winding
an elastic sheet around a peripheral surface of a mandrel, the
method comprising the steps of: when the elastic sheet is layered
on the peripheral surface of the mandrel, layering a non-elastic
sheet on an outermost surface of the elastic sheet; and winding the
elastic sheet around the mandrel together with the non-elastic
sheet.
2. The method as claimed in claim 1, wherein the non-elastic sheet
is a sheet made of a fibroid material
3. The method as claimed in claim 2, wherein the non-elastic sheet
comprises a natural fiber, cotton, and a chemical fiber.
4. The method as claimed in claim 1, wherein the non-elastic sheet
is painted to have various designs.
5. An arrow shaft manufactured by a method as claimed in claim
1.
6. An arrow shaft made of an elastic sheet such as carbon or glass
fiber, the arrow shaft comprising: a non-elastic sheet adhered on
an peripheral surface of the elastic sheet.
7. The arrow shaft as claimed in claim 6, wherein the non-elastic
sheet comprises a natural fiber, cotton, and a chemical fiber.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for manufacturing
an archery arrow, and more particularly, to an arrow shaft composed
of a non-elastic fiber and a low elastic fiber, and a method for
manufacturing the same.
[0003] 2. Background of the Related Art
[0004] Generally, a conventional archery arrow comprises, as shown
in FIG. 3, a hollow arrow shaft, an arrow head fitted into a front
end of the arrow shaft, a number of vanes attached to an outer
periphery of a rear end of the arrow shaft, and a notch fitted into
the rear end, the arrow shaft being a major part among the above
components.
[0005] Several methods and materials for manufacturing the arrow
shaft have been proposed. A typical example of arrow shaft
manufacturing methods comprises the steps of: cutting; layering and
winding; tapping; heat treating and cooling; releasing; and
polishing.
[0006] The above method for manufacturing the arrow shaft includes
several disadvantages as follows:
[0007] 1) To put a constant spin on the arrow, after carbon or
glass fiber is layered and formed on a mandrel, and then the arrow
shaft is ground to have a wanted diameter and spin. However the
arrow shaft is accurately ground, a grinding error may be happened.
Furthermore, at the first stage of grinding the material, the
damage of the material is a factor of reducing the strength of the
arrow shaft. There is another drawback of deteriorating the arrow
shaft in that the partial wear is happened on the arrow shaft, and
thus the linearity of the arrow shaft is lost.
[0008] 2) Since a polishing process is performed after previously
aligning the linearity of the arrow shaft prior to polishing the
arrow shaft, the linearity of the arrow shaft is lost, thereby
increasing the percent defective of the arrow shaft.
[0009] 3) Since the material (i.e., carbon fiber or glass fiber) is
layered at larger amount than that of the spin in view of the
grinding amount, the cost of the article is increased. In addition,
there is another drawback that since the surface of the arrow shaft
is damaged, it is impossible to use the arrow shaft during a long
time.
[0010] 4) After the spin and diameter of the arrow shaft are set,
the weight of the arrow shaft is automatically determined due to
the elasticity and specific gravity. Therefore, it is impossible to
change the weight of the arrow shaft. In particular, after the
grinding process, it is impossible to set the weight of the arrow
shaft to a desired weight depending upon the specification.
[0011] 5) According to the typical method, the strength of the
arrow shaft is necessarily reduced due to the grinding of the arrow
shaft. In addition, since the arrow shaft is painted or transferred
or is designed by attaching a sticker on the peripheral surface in
order to camouflage the arrow shaft, an unnecessary process has to
added, thereby causing reduced productivity and increased cost.
[0012] 6) If the transferring process is carried out, recessed
portions are happened on the surface of the arrow shaft due to the
variations of transferred thickness. During a long-range usage, the
recessed portions will be easily worn, and the transferred portions
will be easily detached from the surface of the arrow shaft.
[0013] 7) If the arrow shaft manufactured by the typical method is
damaged, a sharpen portion will be exposed since the material has a
mono-directional elasticity. Such a sharpen portion may can inflict
a fatal injury to a human body.
SUMMARY OF THE INVENTION
[0014] Accordingly, the present invention is directed to a method
of manufacturing an arrow shaft that substantially obviates one or
more problems due to limitations and disadvantages of the related
art.
[0015] An object of the present invention is to provide an arrow
shaft and a method for manufacturing the same, wherein a proper
amount of an elastic sheet such as carbon or glass fiber proper
that determines a spin of the arrow shaft is calculated to obtain a
proper spin, and a proper amount of the elastic sheet is layered on
a mandrel; and a non-elastic fiber or a low elastic fiber that has
no effect on the spin is layered on a top of the elastic sheet.
[0016] Other object of the present invention is to provide an arrow
shaft and a method for manufacturing the same, wherein a
non-elastic fiber is ground to maintain the initial linearity of
the arrow shaft.
[0017] Another object of the present invention is to provide an
arrow shaft and a method for manufacturing the same, wherein a spin
of the arrow shaft can be constantly maintained.
[0018] Still another object of the present invention is to provide
an arrow shaft and a method for manufacturing the same, wherein the
weight of the arrow shaft can be adjusted by controlling the
grinding amount of a non-elastic fiber or a low elastic fiber.
[0019] Further still another object of the present invention is to
provide an arrow shaft and a method for manufacturing the same,
wherein a desired design is printed on a surface of the arrow shaft
using a printing and transferring method.
[0020] Additional advantages, objects, and features of the
invention will be set forth in part in the description which
follows and in part will become apparent to those having ordinary
skill in the art upon examination of the following or may be
learned from practice of the invention. The objectives and other
advantages of the invention may be realized and attained by the
structure particularly pointed out in the written description and
claims hereof as well as the appended drawings.
[0021] To achieve the object and other advantages and in accordance
with the purpose of the invention, as embodied and broadly
described herein, there is provided a method of manufacturing an
arrow shaft by layering and winding an elastic sheet around a
peripheral surface of a mandrel, the method comprising the steps
of: when the elastic sheet is layered on the peripheral surface of
the mandrel, layering a non-elastic sheet on an outermost surface
of the elastic sheet; and winding the elastic sheet around the
mandrel together with the non-elastic sheet.
[0022] According to another aspect of the present invention, there
is provided an arrow shaft made of an elastic sheet such as carbon
or glass fiber, the arrow shaft comprising: a non-elastic sheet
adhered on an peripheral surface of the elastic sheet.
[0023] The non-elastic sheet comprises a natural fiber or cotton,
and a chemical fiber.
[0024] It is to be understood that both the foregoing general
description and the following detailed description of the present
invention are exemplary and explanatory and are intended to provide
further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this application, illustrate embodiment(s) of
the invention and together with the description serve to explain
the principle of the invention. In the drawings:
[0026] FIG. 1 is a schematic view illustrating a process of
manufacturing an arrow shaft according to one preferred embodiment
of the present invention, in which sheets are adhered onto an
external circumference of a mandrel.
[0027] FIG. 2 is a cross sectional view illustrating an arrow shaft
manufactured by the method of the present invention.
[0028] FIG. 3 is a perspective view illustrating the construction
of a typical archery arrow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Reference will now be made in detail to the preferred
embodiment of the present invention, an example of which is
illustrated in the accompanying drawings.
[0030] The method for manufacturing an arrow shaft according to the
present invention comprises the steps of spreading an elastic sheet
such as pre-impregnated or prepreged carbon or glass fiber,
adhering a non-elastic or low elastic fiber, preferably a
pre-impregnated or prepreged natural, synthetic, or glass fiber
onto the elastic sheet, winding them onto a mandrel, and carrying
out tapping, heat treating/cooling, releasing, and polishing
processes.
[0031] FIG. 1 shows a process of winding the sheets onto the
mandrel, the process being a major process of the present
invention. Referring to FIG. 1, according to the method of the
present invention, after a first elastic sheet 102, a second
elastic sheet 104, and a non-elastic fiber sheet 106 are cut to
have a desired length, respectively, the sheets are prepregs or
pre-impregnated and then are wound onto a surface of the mandrel
100.
[0032] The first elastic sheet 102 and second elastic sheet 104 are
made of elastic material. Preferably, the first and second elastic
sheets are made of a sheet made of carbon or glass fiber. One sheet
made of carbon or glass fiber may be used, or a sheet of which the
carbon fiber sheet and the glass fiber sheet are layered may be
used. The non-elastic fiber sheet 106 is referred to a fibroid
material, in particular, a natural fiber or cotton, or a chemical
fiber. The non-elastic fiber may be is painted or transferred with
various designs to be under the disguise of the arrow shaft.
[0033] The arrow shaft 200 prepared by the above winding process
includes, as shown in FIG. 2, the first elastic sheet 102 formed in
a cylindrical shape, and the second elastic sheet 104 adhered onto
the external circumference of the first elastic sheet 102. The
non-elastic fiber sheet 106, preferably a painted fiber, is adhered
onto the external circumference of the second elastic 104. The
arrow shaft 200 constructed as described above can address the
drawbacks contained in the typical arrow shaft. In particular, the
present invention has advantages of controlling the weight of the
arrow shaft and constantly maintaining the initial linearity
thereof.
[0034] One preferred embodiment of the present invention will now
be explained, but the present invention is not limited to the
embodiment.
[0035] Embodiment
[0036] After a releasing agent is applied on the entire surface of
an external circumference of a mandrel in order to easily carry out
a releasing process (i.e., a process of releasing an article from
the mandrel), an adhesive is applied on the releasing agent. A
carbon sheet, a glass fiber sheet, and a natural fiber sheet with
various designs printed are cut to have a desired length,
respectively. At that time, the carbon sheet, the glass fiber
sheet, and the natural fiber sheet are pre-impregnated
(prepregs).
[0037] Next, as shown in FIG. 1, the glass fiber sheet is adhered
on the carbon sheet, and then the natural fiber sheet is adhered on
the glass fiber. After an end of the carbon sheet is adhered on the
surface of the mandrel, the sheets are wound around the mandrel by
a rolling unit (not shown), this process being hereinafter referred
to a rolling process.
[0038] A film is wound around the entire surface of the resultant
executed by the rolling process, preferably the natural fiber
sheet, using a tapping unit (not shown), this process being
hereinafter referred to a tapping process. Preferably, polyethylene
telephthalate resin (PET) film or oriented polypropylene(OPP) film
is used as the above film. The tapping process is executed
immediately prior to the shape of the article executed by the
rolling process, so that air existed between each sheet layer may
be discharged outwardly and an interior layering degree of the
article may be increased.
[0039] And then, the mandrel is heated with gradually varying a
temperature during 4 hours, preferably under a temperature of 80 to
150.degree. C. during 1 to 4 hours, thereby shaping sheet layers
wound around the mandrel. After that, the shaped article is
released from the mandrel.
[0040] Finally, after both ends of the article released from the
mandrel is cut to have a length of approximately 825 mm, the film
is released from the surface of the natural fiber sheet. The method
of manufacturing the arrow shaft is completed by carrying out
centerless polishing on the surface of the natural fiber sheet.
[0041] The method of manufacturing the arrow shaft according to the
preferred embodiment of the present invention has some advantages
as follows:
[0042] A proper amount of the elastic material that determines the
spin of the arrow shaft is previously calculated to obtain a proper
spin, and a non-elastic fiber that has no effect on the spin is
layered on a top of the elastic material, so that the arrow shaft
having no spin variations can be provided.
[0043] Since the non-elastic material is ground, the weight of the
arrow shaft can be adjusted according to the grinding amount. In
addition, the surface of the arrow shaft is smoothed, and thus the
arrow shaft is soft to the touch. In particular, since the
eccentricity and the initial linearity of the arrow shaft can be
maintained.
[0044] The present invention can camouflage the arrow shaft by
painting the non-elastic fiber to have various designs. It can
address drawbacks contained in the typical method that due to the
transferring process the productivity is decreased and the cost is
increased.
[0045] If the arrow shaft manufactured by the present invention is
damaged, since the fiber encloses the damaged portion, a sharpen
portion is not exposed, thereby protecting a human body.
[0046] The present invention grinds not an expensive elastic
material, but an inexpensive non-elastic fiber, thereby reducing
the cost of the arrow shaft and improving the productivity
thereof.
[0047] The forgoing embodiment is merely exemplary and is not to be
construed as limiting the present invention. The present teachings
can be readily applied to other types of apparatuses. The
description of the present invention is intended to be
illustrative, and not to limit the scope of the claims. Many
alternatives, modifications, and variations will be apparent to
those skilled in the art.
* * * * *