U.S. patent application number 13/984001 was filed with the patent office on 2014-02-13 for cane and cylindrical body.
This patent application is currently assigned to KOSUGE & CO., LTD.. The applicant listed for this patent is Kouki Doi, Kazuhiko Kosuge, Akito Miyazaki, Tsutomu Yamamoto. Invention is credited to Kouki Doi, Kazuhiko Kosuge, Akito Miyazaki, Tsutomu Yamamoto.
Application Number | 20140041702 13/984001 |
Document ID | / |
Family ID | 46638311 |
Filed Date | 2014-02-13 |
United States Patent
Application |
20140041702 |
Kind Code |
A1 |
Yamamoto; Tsutomu ; et
al. |
February 13, 2014 |
Cane and Cylindrical Body
Abstract
Provided is a cane that has a sufficient impact-resistant
strength; and is excellent in safety, durability and repairability
and also lightweight but has a high stiffness. Such a cane has a
shaft (4) and a grip, the shaft (4) comprising a
high-strength-organic-fiber-reinforced-resin layer (31) and a
carbon-fiber-reinforced-resin layer (32), the
high-strength-organic-fiber-reinforced-resin layer (31) being
integrally laminated onto each of the outside and inside surfaces
of the carbon-fiber-reinforced-resin layer (32), the shaft (4)
comprising a glass-fiber-reinforced-resin layer (33a) on the inner
side of the innermost high-strength-organic-fiber-reinforced-resin
layer (31a), the shaft (4) comprising a
glass-fiber-reinforced-resin layer (33b) on the outer side of the
outermost high-strength-organic-fiber-reinforced-resin layer
(31b).
Inventors: |
Yamamoto; Tsutomu; (Shiga,
JP) ; Kosuge; Kazuhiko; (Tokyo, JP) ;
Miyazaki; Akito; (Hyogo, JP) ; Doi; Kouki;
(Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yamamoto; Tsutomu
Kosuge; Kazuhiko
Miyazaki; Akito
Doi; Kouki |
Shiga
Tokyo
Hyogo
Kanagawa |
|
JP
JP
JP
JP |
|
|
Assignee: |
KOSUGE & CO., LTD.
Tokyo
JP
|
Family ID: |
46638311 |
Appl. No.: |
13/984001 |
Filed: |
October 20, 2011 |
PCT Filed: |
October 20, 2011 |
PCT NO: |
PCT/JP2011/074183 |
371 Date: |
October 23, 2013 |
Current U.S.
Class: |
135/77 ; 135/65;
428/36.4 |
Current CPC
Class: |
A45B 9/02 20130101; A45B
9/00 20130101; A61H 2201/0161 20130101; A45B 2009/007 20130101;
A61H 3/06 20130101; Y10T 428/1372 20150115; A45B 9/04 20130101;
A45B 2009/005 20130101 |
Class at
Publication: |
135/77 ;
428/36.4; 135/65 |
International
Class: |
A45B 9/04 20060101
A45B009/04; A45B 9/00 20060101 A45B009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 9, 2011 |
JP |
2011-026414 |
Sep 29, 2011 |
JP |
2011-213921 |
Claims
1. A cane having a shaft and a grip provided at the upper end of
the shaft, the shaft comprising a
high-strength-organic-fiber-reinforced-resin layer and a
carbon-fiber-reinforced-resin layer, the
high-strength-organic-fiber-reinforced-resin layer being integrally
laminated onto at least the outside surface of the
carbon-fiber-reinforced-resin layer.
2. The cane according to claim 1, wherein the
high-strength-organic-fiber-reinforced-resin layer is integrally
laminated onto each of the outside and inside surfaces of the
carbon-fiber-reinforced-resin layer.
3. The cane according to claim 1, wherein the high-strength organic
fiber is a para-aramid fiber.
4. The cane according to claim 1, wherein the shaft comprises a
glass-fiber-reinforced-resin layer on the inner side of the
innermost high-strength-organic-fiber-reinforced-resin layer.
5. The cane according to claim 1, wherein the shaft comprises a
glass-fiber-reinforced-resin layer on the outer side of the
outermost high-strength-organic-fiber-reinforced-resin layer.
6. The cane according to claim 1, wherein the shaft comprises an
indicating layer on the outer side of the outermost
high-strength-organic-fiber-reinforced-resin layer.
7. The cane according to claim 6, wherein a cylindrical
glass-fiber-reinforced-resin layer is provided on the outer side of
the indicating layer.
8. The cane according to claim 6, wherein a wear-resistant
transparent resin layer is provided on the outer side of the
indicating layer.
9. The cane according to claim 1, wherein the shaft is
hollow-structured, and in the cross-section perpendicular to the
axis of the shaft, the cross-sectional area ratio of a hollow and a
shell surrounding the hollow is 85:15 to 56:44.
10. The cane according to claim 1, wherein the shaft consists of a
plurality of mutually connectable and separable shaft parts, and in
the shaft parts adjacent to each other, a first connecting end of
one shaft part is provided with a smaller-diameter part that can be
inserted into and removed from a second connecting end of the
opposite shaft part.
11. The cane according to claim 10, wherein the smaller-diameter
part is formed of a high-strength-organic-fiber-reinforced-resin
layer.
12. The cane according to claim 10, wherein a cylindrical joint
cover is provided to cover the first connecting end and the second
connecting end which are connected to each other, one end of the
joint cover being fitted onto one of the first and second
connecting ends and fixed thereto, the other end of the joint cover
being configured such that the other connecting end can be inserted
thereinto and removed therefrom.
13. The cane according to claim 1, wherein the grip has a
hollow-structured grip body extended from the upper end of the
shaft, and the cross-section perpendicular to the axis of the grip
body is larger than that of the shaft.
14. The cane according to claim 1, wherein the grip is formed of a
high-strength fiber-reinforced resin.
15. The cane according to claim 1, wherein the grip has an antislip
member on at least part of the outer surface thereof.
16. A cane having a shaft and a ferrule attached to the lower end
of the shaft, the ferrule being formed of a high-strength organic
fiber-reinforced resin in which staple fibers of a high-strength
organic fiber are dispersed in a synthetic resin.
17. The cane according to claim 16, wherein the ratio of the
high-strength organic fiber in the high-strength organic
fiber-reinforced resin is 10 to 60 mass %.
18. The cane according to claim 16, wherein the staple fibers
dispersed in the synthetic resin have a filament fineness of 1.1 to
2.3 dtex and a fiber length of 2 to 8 mm.
19. The cane according to claim 16, wherein the shaft comprises a
high-strength-organic-fiber-reinforced-resin layer and a
carbon-fiber-reinforced-resin layer, the
high-strength-organic-fiber-reinforced-resin layer being integrally
laminated onto at least the outside surface of the
carbon-fiber-reinforced-resin layer.
20. The cane according to claim 1, wherein the cane is a white
cane.
21. A cylindrical body comprising a cylindrical
high-strength-organic-fiber-reinforced-resin layer and a
cylindrical carbon-fiber-reinforced-resin layer, the
high-strength-organic-fiber-reinforced-resin layer being integrally
laminated onto at least the outside surface of the
carbon-fiber-reinforced-resin layer.
22. The cylindrical body according to claim 21, wherein the
high-strength-organic-fiber-reinforced-resin layer is integrally
laminated onto each of the outside and inside surfaces of the
carbon-fiber-reinforced-resin layer.
23. The cylindrical body according to claim 21, wherein the
high-strength organic fiber is a para-aramid fiber.
24. The cylindrical body according to claim 21, comprising a
glass-fiber-reinforced-resin layer on the inner side of the
innermost high-strength-organic-fiber-reinforced-resin layer.
25. The cylindrical body according to claim 21, comprising a
cylindrical glass-fiber-reinforced-resin layer on the outer side of
the outermost high-strength-organic-fiber-reinforced-resin
layer.
26. The cylindrical body according to claim 21, wherein, in the
cross-section perpendicular to the axis of the cylindrical body,
the cross-sectional area ratio of a hollow and a shell surrounding
the hollow is 85:15 to 56:44.
27. The cylindrical body according to claim 21, which is used as a
shaft of a cane having a grip provided at the upper end of the
shaft.
Description
TECHNICAL FIELD
[0001] The present invention relates to a cane such as a white cane
for the visually disabled. More particularly, the present invention
relates to a cane that has a sufficient impact-resistant strength
against a force in a direction perpendicular to the axis of its
shaft; and is excellent in safety, durability and repairability and
also lightweight but has a high stiffness.
BACKGROUND ART
[0002] A cane is also called a stick or a pole, and used not only
by the visually disabled and people with limb disabilities, such as
elderly people, but also by healthy people for trekking, light
mountain climbing, etc. Such a cane usually has a rod-shaped shaft,
a grip which is designed for the user to grasp and formed at the
upper end of the shaft, and a ferrule attached to the lower end of
the shaft. Conventional canes, although are more or less
structurally different from each other, are made of wood, an
aluminum alloy, etc. in the most cases.
[0003] For example, a so-called white cane for the visually
disabled is usually used with its tip slightly lifted from the
ground for a prolonged period, and thus weight saving is desired,
but conventional wooden canes are heavy and give a heavy burden to
the users. Furthermore, such wooden canes are unsatisfactory in
strength, and may be repeatedly swelled and dried by environmental
changes, resulting in undesired warpage of the shaft and detachment
of the superficial coating thereof. Aluminum alloy canes are more
lightweight than wooden canes, but still heavy for prolonged use
and disadvantageously tend to dent and bend in response to
impact.
[0004] Meanwhile, a cane having a shaft made of a carbon
fiber-reinforced resin is recently proposed (for example, see
Patent Literature 1). The cane having such a shaft is more
lightweight than conventional wooden canes and aluminum alloy canes
and is resistant to undesired warpage and corrosion.
[0005] However, the cane according to Patent Literature 1, although
is more lightweight than conventional canes made of wood, an
aluminum alloy, etc., is not lightweight enough, particularly to
allow the visually disabled etc. to use for a prolonged period, and
thus further weight saving is desired.
[0006] The above-mentioned cane having a shaft made of a carbon
fiber-reinforced resin has, due to the high tensile strength and
elastic modulus of carbon fibers, such a high flexural modulus as
applied to, for example, a golf shaft. However, since carbon fibers
as inorganic fibers have a low elongation and lack flexibility, the
shaft disadvantageously tends to break in response to an impact in
a direction transverse to the shaft (flexural impact). Considering
this, the above-mentioned shaft has a sufficient mechanical
strength as a golf shaft in striking, but is unsatisfactory as a
cane shaft. This is because a cane using this shaft is given an
impact when the user frequently hits the road surface and obstacles
with the cane in order to examine their conditions, and the impact
is transmitted to the shaft via the ferrule and may cause
microcracks in the carbon fiber. Thus, when given an external force
by bumps (against a person, a bicycle and other obstacles), etc.,
the cane may easily fracture at the site where cracks have been
generated. Therefore, development of a cane having a sufficient
strength (flexural stiffness) against a force in a transverse
direction, namely a direction perpendicular to the axis of its
shaft is desired.
[0007] Further, the above-mentioned cane having a shaft made of a
carbon fiber-reinforced resin may fracture in response to impact
etc., be heavily damaged on the fracture surface, and have spiky
ends of stiff fibers projected from the fracture surface. In this
case, for example, when the visually disabled check the fracture
site and the damage level, naturally by touch, the fibers exposed
on the fracture surface may get stuck in the hand. Therefore, the
above-mentioned cane needs to be thicker-walled so as not to easily
fracture at the time of impact etc., but in this case, the weight
of the cane is increased. Further, the repairability of the
above-mentioned cane is unsatisfactory because the fracture site is
damaged so heavily that simple repair on site is difficult. Thus,
development of a cane that can be easily repaired on site has been
desired.
[0008] The above-mentioned disadvantages can be overcome, for
example, by forming a shaft using a high-strength organic
fiber-reinforced resin composed of a para-aramid fiber, an epoxy
resin and the like. However, such a shaft is excellent in impact
resistance but has a lower stiffness compared with the shaft formed
of a carbon fiber-reinforced resin. This stiffness of the shaft can
be enhanced by thickening the layer of the high-strength organic
fiber-reinforced resin, but in this case, the shaft is thicker, the
amount of the resin used is increased and the weight of the cane is
excessively increased.
CITATION LIST
Patent Literature
[0009] Patent Literature 1: JP-A 2005-218473
SUMMARY OF INVENTION
Technical Problem
[0010] A technical problem to be solved by the present invention is
to provide a cane that is free from the above-mentioned
disadvantages; has a sufficient impact-resistant strength against a
force in a direction perpendicular to the axis of its shaft; and is
excellent in safety, durability and repairability and also
lightweight but has a high stiffness.
Solution to Problem
[0011] As a solution to the above-mentioned problem, the present
invention has, for example, the following constitutions, which will
be described based on FIGS. 1 to 18 showing embodiments of the
present invention.
[0012] That is to say, the present invention relates to a cane
having a shaft (4) and a grip (1) provided at the upper end of the
shaft (4), the shaft (4) comprising a
high-strength-organic-fiber-reinforced-resin layer (31) and a
carbon-fiber-reinforced-resin layer (32), the
high-strength-organic-fiber-reinforced-resin layer (31) being
integrally laminated onto at least the outside surface of the
carbon-fiber-reinforced-resin layer (32).
[0013] The present invention 2 is a cylindrical body, comprising a
cylindrical high-strength-organic-fiber-reinforced-resin layer (31)
and a cylindrical carbon-fiber-reinforced-resin layer (32), the
high-strength-organic-fiber-reinforced-resin layer (31) being
integrally laminated onto at least the outside surface of the
carbon-fiber-reinforced-resin layer (32).
[0014] The organic fiber which constitutes the
high-strength-organic-fiber-reinforced-resin layer is lightweight
but has a high tensile strength. Also, since organic fibers have a
higher elongation compared with inorganic fibers such as carbon
fibers, for example, even when the user hits the ground etc. with
the tip of the cane, there is no possibility of impact-triggered
microcrack generation in the organic fiber. Further, when the shaft
or the cylindrical body is given an impact in a direction
perpendicular to the axial direction (flexural impact), the
high-strength-organic-fiber-reinforced-resin layer buckles and
deforms without fracturing, and buffers this impact.
[0015] The carbon-fiber-reinforced-resin layer in each of the shaft
and the cylindrical body has a high stiffness since carbon fibers
have a higher elastic modulus than that of organic fibers, and thus
the high-strength-organic-fiber-reinforced-resin layer does not
have to be excessively thick.
[0016] Carbon fibers themselves easily break in response to
flexural impact, but since the carbon-fiber-reinforced-resin layer
has a high-strength-organic-fiber-reinforced-resin layer integrally
laminated onto the outside surface and is protected thereby, even
if carbon fibers break in response to an impact in a direction
perpendicular to the axis of the shaft or the cylindrical body, the
shaft or the cylindrical body only buckles and deforms without
heavily fracturing, and broken spiky carbon fibers are prevented
from projecting from the fracture site. In addition, a cane buckled
and deformed in the shaft etc. can be easily repaired by use of,
for example, a commercial repair kit etc.
[0017] The high-strength-organic-fiber-reinforced-resin layer is
integrally laminated onto at least the outside surface of the
carbon-fiber-reinforced-resin layer, and may be integrally
laminated onto each of the outside and inside surfaces. The latter
case is preferable since the carbon-fiber-reinforced-resin layer is
sandwiched in between the inner and outer
high-strength-organic-fiber-reinforced-resin layers and protected
thereby much more favorably, and thus fracture of the shaft or the
cylindrical body is prevented.
[0018] The high-strength organic fiber is not limited to specific
kinds as long as it has a high mechanical strength (for example,
tensile strength), etc. Examples thereof include
ultra-high-molecular-weight-polyethylene fibers, wholly-aromatic
polyamide fibers, wholly-aromatic polyester fibers, heterocyclic
high-performance fibers and polyacetal fibers. These fibers can be
used alone or as a mixture formed of two or more kinds at any
ratio. Specifically, para-aramid fibers are preferably used and
poly(p-phenylene terephthalamide) fibers are particularly
preferable.
[0019] The shaft and the cylindrical body each comprise at least
one carbon-fiber-reinforced-resin layer and at least one
high-strength-organic-fiber-reinforced-resin layer, and one or both
of the carbon-fiber-reinforced-resin layer and the
high-strength-organic-fiber-reinforced-resin layer may be plural.
It is also possible that the shaft and the cylindrical body each
consist of these layers. However, it is preferable that the shaft
comprises a cylindrical glass-fiber-reinforced-resin layer on the
inner side of the innermost
high-strength-organic-fiber-reinforced-resin layer. One reason for
this is that such a constitution can provide a favorable wear
resistance of the inner surface. Another reason is that, when the
shaft or the cylindrical body is cut into pieces of a predetermined
length etc., such a constitution can prevent organic fibers from
raveling on the inner surfaces of the cut ends and keep the cut
ends in a favorable shape.
[0020] It is also preferable that the shaft comprises a cylindrical
glass-fiber-reinforced-resin layer on the outer side of the
outermost high-strength-organic-fiber-reinforced-resin layer. One
reason for this is that such a constitution can provide a favorable
wear resistance of the outer surface. Another reason is that, when
the shaft or the cylindrical body is cut into pieces of a
predetermined length etc., such a constitution can prevent organic
fibers from raveling on the outer surfaces of the cut ends and keep
the cut ends in a favorable shape.
[0021] For function as an external indicator to help, for example,
the visually disabled to recognize the location and the function of
the cane, or for decoration etc., the shaft preferably comprises an
indicating layer on the outer side of the outermost
high-strength-organic-fiber-reinforced-resin layer. The indicating
layer may be a coating film of any color, pattern or the like, but
is preferably a reflective tape, a red-colored tape, etc. because
such tapes enable easy formation of the indicating layer in a
predetermined color etc., easy repair thereof and the like.
[0022] The indicating layer on the outer surface of the shaft may
be externally exposed, but it is preferable that a cylindrical
glass-fiber-reinforced-resin layer or a wear-resistant transparent
resin layer is provided on the outer side of the indicating layer.
This is because that the indicating layer protected by such a
glass-fiber-reinforced-resin layer or wear-resistant transparent
resin layer has an increased wear resistance and water resistance
and can also be prevented from changing in color and getting
detached from the shaft.
[0023] The cross-sectional shape of the shaft is not limited to
specific kinds and may be an odd shape, but is preferably a
circular shape. Examples of the odd shape include an oval shape, a
hollow shape, an X shape, a Y shape, a T shape, an L shape, a star
shape, a leaf shape (for example, a 3-leaf shape, a 4-leaf shape, a
5-leaf shape, etc.) and other multangular shapes (for example, a
triangular shape, a square shape, a pentagonal shape, a hexagonal
shape, etc.).
[0024] The shaft may be solid unless the effects of the present
invention are hindered, but in terms of weight saving of the cane,
it is preferable that the shaft is a hollow structure composed of a
hollow and a shell surrounding the hollow. In the cross-section
perpendicular to the axis of the shaft, the cross-sectional area
ratio of the hollow and the shell is not limited to specific values
unless the ratio hinders the effects of the present invention. In
order that the shaft may have a sufficient strength against a force
perpendicular to the axial direction and be so lightweight as to
allow prolonged use, the cross-sectional area ratio is preferably
85:15 to 56:44, and further considering excellent safety and
repairability, the cross-sectional area ratio is more preferably
80:20 to 60:40, and particularly preferably 75:25 to 62:38. When
the cross-sectional area ratio of the hollow to the whole of the
shaft is less than 56%, the cane is not sufficiently lightweight
and has such a hard shaft to tend to make the user exhausted in
prolonged use, and therefore this case is not preferable.
Conversely, when the cross-sectional area ratio of the hollow to
the whole of the shaft exceeds 85%, the cane is too lightweight and
does not have a sufficient strength against a force perpendicular
to the axial direction, and therefore this case is not preferable,
either.
[0025] The cane may be a non-foldable, so-called, straight cane
having a shaft formed of one cylindrical body etc. Such a shaft
without junctions etc. is lightweight and thus is preferable.
Alternatively, the cane of the present invention may be a so-called
folding cane having a shaft composed of a plurality of shaft parts.
Such a cane, while not in use, can be folded up into a size compact
enough to easily carry and thus is also preferable.
[0026] In the case of the above-mentioned folding cane, the shaft
is composed of a plurality of mutually connectable and separable
shaft parts, and in the shaft parts adjacent to each other, a first
connecting end of one shaft part is provided with a
smaller-diameter part that can be inserted into and removed from a
second connecting end of the opposite shaft part. In this case, the
number of shaft parts, i.e., the number of folds is not limited to
specific numbers, and depending on the cane length and the folded
dimensions, may be any appropriate number, for example, 5 to 7. The
smaller-diameter part may be produced separately from the shaft
part and attached thereto with an adhesive, or be formed integrally
with the connecting end of the shaft part. The adhesive may be a
known adhesive and is not particularly limited.
[0027] The material of the smaller-diameter part is not limited to
specific kinds, but it is preferable that the smaller-diameter part
is formed of a high-strength-organic-fiber-reinforced-resin layer
as used for the shaft because this
high-strength-organic-fiber-reinforced-resin layer can favorably
reinforce the junction(s) of shaft parts and effectively prevent
fracture at the junction(s), which is susceptible to stress. It is
more preferable that the smaller-diameter part is formed of only a
high-strength-organic-fiber-reinforced-resin layer composed of a
para-aramid fiber and the like.
[0028] Preferably, the folding cane comprises a cylindrical joint
cover to cover the first connecting end and the second connecting
end which are connected to each other, one end of the joint cover
being fitted onto one of the first and second connecting ends and
fixed thereto, the other end of the joint cover being configured
such that the other connecting end can be inserted thereinto and
removed therefrom. This is advantageous because such a joint cover
can tightly hold the ends of these shaft parts connected to each
other and does not allow any backlash.
[0029] The shape of the grip is not particularly limited unless the
shape hinders the effects of the present invention, and examples
thereof include an I shape and a T shape. The grip may be composed
of only resin, or formed by coating the outside of any core with
resin. The grip is preferably hollow structured in terms of weight
saving, and in this case, a hollow structured core may be used.
[0030] The resin used for the grip is not particularly limited
unless the resin hinders the effects of the present invention.
Examples thereof include polyester resins, polyamide resins (for
example, nylons such as nylon 6, 66 nylon and MC nylon), acrylate
resins, ABS resins, polyolefin resins (for example, polypropylene
resins, polyethylene resins, etc.), polybutylene terephthalate
resins and polyethylene terephthalate resins. Fiber-reinforced
resins may be also used. Examples of the material used for the core
include silicone and nylon. In particular, it is preferable that
the grip is formed of, for example, the same materials as those of
the shaft, namely a carbon fiber-reinforced resin and a
high-strength organic fiber-reinforced resin, because such a grip
is lightweight, highly strong and producible at low cost.
[0031] The dimensions such as the length and diameter of the grip
are appropriately determined if needed. The production method of
the grip is not particularly limited and known methods can be used.
Commercial products may be also used.
[0032] Preferably, the grip has a hollow-structured grip body
extended from the upper end of the shaft, the cross-section
perpendicular to the axis of the grip body being larger than that
of the shaft. This is advantageous because such a grip is
lightweight but thick enough for the user to firmly grasp. The
outer surface of the grip body may be externally exposed as it is,
or be in an antislip shape such as uneven patterns. However, it is
preferable that the grip has an antislip member on at least part of
the outer surface of the grip body etc., the antislip member being
a coating layer formed of rubber, a synthetic resin, etc. or being
a commercial grip tape or the like. This is advantageous because
the user can securely grasp such a grip.
[0033] A ferrule may be provided at the lower end of the shaft. The
shape and material of the ferrule are not limited to specific
kinds, but it is preferable that the ferrule is formed of a
high-strength organic fiber-reinforced resin in which staple fibers
of a high-strength organic fiber are dispersed in a synthetic
resin, because such a ferrule is excellent in usage characteristics
and wear resistance.
[0034] That is to say, in the case of a cane having a ferrule
formed of such a high-strength organic fiber-reinforced resin, when
the user, while walking, lightly hits and traces the road surface
with the tip of the cane in order to examine the conditions
thereof, the ferrule favorably reacts against the objects. For
example, when the ferrule touches the road surface, the ferrule
lightly bounces back therefrom and transmits information such as
the degree of bouncing-back movement, a sound generated when the
ferrule hits the road surface, and a feel given when the ferrule
moves along the road surface, and such information clearly varies
with the kind and material of the road surface such as an asphalt
pavement and a concrete pavement. Such a movement and the like are
considered to be influenced collectively by various characteristics
of the ferrule, such as hardness, density, elastic coefficient,
frictional resistance and wear resistance, based on the material of
the ferrule.
[0035] Accordingly, a cane having such a ferrule is advantageous
because the cane can clearly transmit information to the user,
regarding not only obstacles and unevenness on the road surface but
also detailed unevenness, feels of materials, etc., so as to enable
more accurate recognition of the kind of the road surface toward
the walking direction etc., and therefore the visually disabled can
walk more safely with a sense of great security. More
advantageously, since the ferrule favorably reacts against objects
to be examined, the necessity of excessively swinging around the
cane or poking about therewith is reduced and the burden to the
user's hand and wrist is reducible. More advantageously, the sound
generated when the cane hits objects to be examined is not so loud,
and thus the manipulability is excellent. From the above, it is
understood that the cane is excellent in usage characteristics and
particularly preferable as a white cane for the visually disabled
because the cane favorably works as a sensor, and that the cane is
also lightweight and excellent in durability.
[0036] The high-strength organic fiber content of the high-strength
organic fiber-reinforced resin is not limited to specific amounts.
However, when the content is too small, usage characteristics and
wear-resistant effect are not sufficiently obtained, and when the
content is excessively high, the fibers cannot be easily dispersed
in the synthetic resin. Therefore, the content ratio of the
high-strength organic fiber is preferably 10 to 60 mass %, and more
preferably 20 to 50 mass %.
[0037] The high-strength organic fiber is not limited to specific
kinds as long as it has a high mechanical strength (for example,
tensile strength), etc. Examples thereof include
ultra-high-molecular-weight-polyethylene fibers, wholly-aromatic
polyamide fibers, wholly-aromatic polyester fibers, heterocyclic
high-performance fibers and polyacetal fibers. These fibers can be
used alone or as a mixture formed of two or more kinds at any
ratio. Specifically, para-aramid fibers are preferably used, and
because of the properties of being easily fibrillated and
dispersible, poly(p-phenylene terephthalamide) fibers are
particularly preferable.
[0038] The high-strength organic fiber is dispersed as a staple
fiber in the synthetic resin. The thickness and length of the
staple fiber are not limited to specific values as long as the
staple fiber can be dispersed in the synthetic resin. Inter alia, a
high-strength organic fiber with a filament fineness of about 1.1
to 2.3 dtex and with a fiber length of about 2 to 8 mm can
favorably disperse and thus is preferable. Further, such a
high-strength organic fiber can sufficiently deliver usage
characteristics, wear resistance, etc. required for ferrules.
[0039] The synthetic resin is not limited to specific kinds as long
as it can disperse high-strength organic fibers and be formed into
a ferrule, but is preferably a thermoplastic synthetic resin in
terms of easy shaping. Specific examples thereof include polyester
resins, polyamide resins (for example, nylons such as 6 nylon, 66
nylon and MC nylon), acrylate resins, ABS resins, polyolefin resins
(for example, polypropylene resins, polyethylene resins, etc.),
polybutylene terephthalate resins and polyethylene terephthalate
resins. Polyamide resins are particularly preferable because of
their excellent wear resistance.
Advantageous Effects of Invention
[0040] The present invention, which has constitutions and functions
as described above, exhibits the following effects.
(1) Since the carbon-fiber-reinforced-resin layer has a high
stiffness, even when given a force in the axial direction, the
shaft does not curve or bend, and thus the user can use the cane
with a sense of security. (2) Since the
high-strength-organic-fiber-reinforced-resin layer is excellent in
vibration damping, vibration etc. of the tip of the cane can be
accurately transmitted to the user's hand. (3) Since a lightweight
high-strength-organic-fiber-reinforced-resin layer and a highly
stiff carbon-fiber-reinforced-resin layer are comprised in
combination, the shaft and the cylindrical body each have a high
strength and are lightweight without the need of an excessively
thick high-strength-organic-fiber-reinforced-resin layer. (4) Since
the high-strength-organic-fiber-reinforced-resin layer is
comprised, even when the user hits the ground, obstacles, etc. with
the tip of the cane, there is no possibility of impact-triggered
microcrack generation in the high-strength organic fiber, and thus
the durability is excellent. (5) Even when a great flexural impact
is applied in a direction perpendicular to the axial direction, the
high-strength-organic-fiber-reinforced-resin layer can buffer the
impact by buckling deformation, deliver an excellent performance in
mechanical strength such as impact resistance, and thus favorably
prevent the shaft from fracturing. (6) Even if carbon fibers break
in response to a great flexural impact in a direction perpendicular
to the axial direction, the carbon-fiber-reinforced-resin layer is
protected by the high-strength-organic-fiber-reinforced-resin layer
integrally laminated onto the outside surface thereof, and thus
heavily fracturing is prevented. Broken spiky carbon fibers are
also prevented from projecting from the site to which the flexural
impact has been given. Accordingly, for example, the visually
disabled etc. can safely check such a damaged site by touch or the
like. (7) Since each of the shaft and the cylindrical body does not
easily fracture even when given a great flexural impact in a
direction perpendicular to the axial direction, they can be easily
repaired by use of, for example, a commercial repair kit etc., for
example, at the venue where the impact has been given, and the
repaired cane etc. can be continuously used.
BRIEF DESCRIPTION OF DRAWINGS
[0041] FIG. 1 shows a first embodiment of the present invention,
FIG. 1 (a) is an outline view of a straight cane, and FIG. 1 (b) is
an A-A arrowed cross-sectional view of FIG. 1 (a). An outline view
of a straight cane is shown.
[0042] FIG. 2 is a partially cutaway view showing the laminated
structure of the shaft according to the first embodiment.
[0043] FIG. 3 is a partially cutaway view of the grip of the cane
according to the first embodiment.
[0044] FIG. 4 is a partial cutaway and perspective view showing the
vicinity of the ferrule of the cane according to the first
embodiment.
[0045] FIG. 5 is a partially cutaway view showing the laminated
structure of the shaft according to a second embodiment of the
present invention.
[0046] FIG. 6 shows a third embodiment of the present invention,
FIG. 6 (a) is an outline view of a folding cane, and FIG. 6 (b) is
an enlarged sectional view of part B in FIG. 6 (a).
[0047] FIG. 7 is an outline view of the cane in a folded state
according to the third embodiment.
[0048] FIG. 8 is a sectional view of the vicinity of the joint
cover of the cane in an unconnected state according to the third
embodiment.
[0049] FIG. 9 is a sectional view of the vicinity of the joint
cover of the cane in a connected state according to the third
embodiment.
[0050] FIG. 10 is an outline view of the grip according to modified
example 1 of the present invention.
[0051] FIG. 11 is a segmentary view of the vicinity of the ferrule
according to modified example 2 of the present invention.
[0052] FIG. 12 is a perspective view showing the emergency repair
kit used for the repairability test.
[0053] FIG. 13 is a perspective view showing the state of the main
part of the cylindrical body in the repairability test.
[0054] FIG. 14 is comparison table 1 showing the measurement
results of each characteristic value of the shaft of the present
invention in comparison with Comparative Examples.
[0055] FIG. 15 is a schematic view of the measuring device used for
measurement of the wear resistance of the outer surface of the
shaft.
[0056] FIG. 16 shows the road surfaces used for examination of the
usage characteristics of the ferrule, FIG. 16 (a) is an image of an
asphalt pavement, FIG. 16 (b) is an image of a concrete pavement
arranged with gravels on the surface, and FIG. 16 (c) is an image
of a concrete pavement with a tiled pattern.
[0057] FIG. 17 is comparison table 2 showing the measurement
results on the usage characteristics of the ferrule of the present
invention in comparison with Comparative Examples.
[0058] FIG. 18 is comparison table 3 showing the measurement
results on the wear property of the ferrule of the present
invention in comparison with Comparative Examples.
DESCRIPTION OF EMBODIMENTS
[0059] Hereinafter, the present invention will be described in
detail based on the drawings.
[0060] As shown in FIG. 1 (a), a cane (7) of a first embodiment has
a shaft (4), a grip (1) provided at the upper end of the shaft (4),
and a ferrule (6) fixedly attached to the lower end of the shaft
(4).
[0061] As shown in FIG. 1 (b), the shaft (4) is in the shape of a
hollow cylinder of which the cross-section perpendicular to the
axis is in a circular shape. As shown in FIG. 2, the shaft (4)
comprises a cylindrical
high-strength-organic-fiber-reinforced-resin layer (31), a
cylindrical carbon-fiber-reinforced-resin layer (32), and a
cylindrical glass-fiber-reinforced-resin layer (33).
[0062] That is to say, a first
high-strength-organic-fiber-reinforced-resin layer (31a) is
integrally laminated onto the inside surface of the
carbon-fiber-reinforced-resin layer (32), and a cylindrical first
glass-fiber-reinforced-resin layer (33a) is integrally laminated
onto the inside surface of the first
high-strength-organic-fiber-reinforced-resin layer (31a). Further,
a second high-strength-organic-fiber-reinforced-resin layer (31b)
is integrally laminated onto the outside surface of the
carbon-fiber-reinforced-resin layer (32), and a cylindrical second
glass-fiber-reinforced-resin layer (33b) is integrally laminated
onto the outside surface of the second
high-strength-organic-fiber-reinforced-resin layer (31b).
[0063] As shown in FIGS. 1 and 2, to the outside surface of the
second glass-fiber-reinforced-resin layer (33b), which is laminated
onto the outside surface of the second
high-strength-organic-fiber-reinforced-resin layer (31b), a white
reflective tape (15) and a red-colored tape (16) are attached as an
indicating layer (34). The outside surface of the indicating layer
(34) is covered with a wear-resistant transparent resin layer (35).
As long as the wear-resistant transparent resin layer (35) is so
excellent in wear resistance, water resistance, etc. as to
effectively protect the indicating layer (34), the material thereof
is not limited to specific kinds. Specifically, ionomer resin
films, such as HIMILAN (trade name, manufactured by DU PONT-MITSUI
POLYCHEMICALS), and others are used as a monolayer or a
multilayer.
[0064] In the cross-section perpendicular to the axis of the shaft
(4), the cross-sectional area ratio of a hollow (17) and a shell
(18) surrounding the hollow is not limited to specific values. In
order that the shaft may have a sufficient strength and stiffness
against a force perpendicular to the axial direction and be so
lightweight as to allow prolonged use, the cross-sectional area
ratio is appropriately selected from the ranges of usually 85:15 to
56:44, preferably 80:20 to 60:40, and more preferably 75:25 to
62:38.
[0065] To prevent the shaft (4) from easily fracturing even when
the shaft (4) is given an impact perpendicular to the axial
direction, for example when a bicycle bumps against the user of the
cane (7), the impact resistance against a force perpendicular to
the axial direction is preferably such a degree that an impact
energy of 10J or larger is absorbable. In terms of increased safety
and repairability, 15J or larger is more preferable. The impact
resistance can be measured using the Drop Weight Impact Tester
manufactured by Instron (product name: Drop Weight Impact Tester,
Dynatup (registered trademark) 9200 series), etc., according to the
three point flexural test specified in JIS K 7055:1995 (Testing
method for flexural properties of glass fiber-reinforced
plastics).
[0066] The shaft (4) may be a tapered cylindrical body in which the
outer diameter changes in the direction from one end toward the
other end, but it is preferable that the shaft (4) is a cylindrical
body in which the outer diameter is at constant length from one end
to the other end, because such a shaft (4) can be easily produced
by forming a cylinder of any length and cutting into pieces of a
predetermined dimension.
[0067] The high-strength-organic-fiber-reinforced-resin layer (31)
which constitutes the shaft (4) can be produced by a known method,
that is, for example, by impregnating high-strength organic fibers,
such as para-aramid fibers, with resin such as an epoxy resin,
shaping the mixture into a predetermined cylinder, heating the
cylinder, for example, at a temperature of room temperature to
about 130.degree. C. for curing of the resin, and cutting the cured
product into pieces of a predetermined length. The
carbon-fiber-reinforced-resin layer (32) and the
glass-fiber-reinforced-resin layer (33) can be similarly
produced.
[0068] The organic fiber which constitutes the
high-strength-organic-fiber-reinforced-resin layer (31) is not
limited to specific kinds. For example, any of
ultra-high-molecular-weight-polyethylene fibers, wholly-aromatic
polyamide fibers, wholly-aromatic polyester fibers, heterocyclic
high-performance fibers, polyacetal fibers and the like can be used
alone or in a combination of two or more kinds.
[0069] Examples of the carbon fiber which constitutes the
carbon-fiber-reinforced-resin layer (32) include
polyacrylonitrile-based carbon fibers and pitch-based carbon
fibers. Examples of the glass fiber which constitutes the
glass-fiber-reinforced-resin layer (33) include alkali glass
fibers, alkali-free glass fibers and low-dielectric glass fibers.
However, the organic, carbon and glass fibers used for the present
invention are not limited to the foregoing examples.
[0070] The ultra-high-molecular-weight-polyethylene fiber means a
fiber composed of ultra-high-molecular-weight-polyethylene resin.
Here, a suitable ultra-high-molecular-weight-polyethylene resin has
a molecular weight of about 200,000 or more, preferably about
600,000 or more, and examples thereof include, besides
homopolymers, copolymers with lower .alpha.-olefins having about 3
to 10 carbon atoms such as propylene, butene, pentene and hexene.
In the case of a copolymer of ethylene with an .alpha.-olefin, it
is suitable that the ratio of the latter per 1000 carbon atoms is
about 0.1 to 20 molecules, preferably about 0.5 to 10 molecules on
average. The method for producing
ultra-high-molecular-weight-polyethylene fibers is disclosed by,
for example, JP-A 55-5228 and JP-A 55-107506, and such disclosed
methods known per se may be used. Commercial products, such as
Dyneema (trade name, manufactured by Toyobo Co., Ltd.), Spectra
(trade name, manufactured by Honeywell International, Inc.), and
HI-ZEX MILLION (trade name, manufactured by Mitsui Chemicals, Inc.)
may be also used as the ultra-high-molecular-weight-polyethylene
fiber.
[0071] The wholly-aromatic polyamide fiber is not particularly
limited and examples thereof include aramid fibers. As the aramid
fiber, para-aramid fibers are preferred. Examples of the
para-aramid fiber include poly(para-phenylene terephthalamide)
fibers (manufactured by DU PONT-TORAY CO., LTD., trade name: KEVLAR
29, 49, 149, etc.) and copoly(p-phenylene-3,4'-diphenyl ether
terephthalamide) fibers (manufactured by TEIJIN LIMITED, trade
name: Technora). Inter alia, poly(p-phenylene terephthalamide)
fibers are particularly preferred. The wholly-aromatic polyamide
fiber can be produced by a known method or its modified method.
Alternatively, the commercial products as mentioned above may be
also used.
[0072] The wholly-aromatic polyester fiber is not particularly
limited and examples thereof include fibers composed of, for
example, a self-condensed polyester made of p-hydroxybenzoic acid,
a polyester made of terephthalic acid and hydroquinone, or a
polyester made of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic
acid. The wholly-aromatic polyester fiber can be produced by a
known method or its modified method. Alternatively, commercial
products such as Vectran (trade name, manufactured by Kuraray Co.,
Ltd.) can be also used.
[0073] The heterocyclic high-performance fiber is not particularly
limited and examples thereof include poly(p-phenylene
benzobisthiazole) (PBZT) fibers and poly(p-phenylene
benzobisoxazole) (PBO) fibers. The heterocyclic high-performance
fiber can be produced by a known method or its modified method.
Alternatively, PBO fibers such as Zylon (trade name, manufactured
by Toyobo Co., Ltd.) and the like can be also used.
[0074] The polyacetal fiber is not particularly limited and can be
produced by a known method or its modified method. Alternatively,
commercial products such as Tenac (trade name, manufactured by
Asahi Kasei Corporation) and Dirline (trade name, manufactured by
Du Pont) can be also used.
[0075] The resin with which the above-mentioned high-strength
organic fibers, carbon fibers or glass fibers are impregnated is
not particularly limited unless the resin hinders the effects of
the present invention. Examples thereof include thermosetting
resins such as epoxy resins, unsaturated polyester resins and vinyl
ester resins. Thermoplastic resins are also included. These resins
can be used alone or as a mixture formed of two or more kinds at
any ratio.
[0076] Examples of the epoxy resin include diglycidyl ether
compounds of bisphenol A, bisphenol AD, bisphenol F or bisphenol S,
or their high-molecular-weight homologs, poly(glycidyl ether) of
phenol novolac, and poly(glycidyl ether) of cresol novolac. In
addition, halogenated derivatives of the foregoing examples can be
also used. Further, aromatic epoxy resins etc. obtainable by
reaction of a phenol, such as bisphenol A, bisphenol AD, bisphenol
F and bisphenol S, with a glycidyl ether thereof may be used, and
aliphatic epoxy resins may be used as well. The epoxy resin is not
particularly limited unless it hinders the effects of the present
invention. The epoxy resin can be obtained according to a known
production method, and commercial products thereof may be also
used.
[0077] The unsaturated polyester resin is not particularly limited
unless it hinders the effects of the present invention. The
unsaturated polyester resin can be produced by a known method, and
commercial products thereof may be also used. For example, the
unsaturated polyester resin can be obtained from an alcohol
component (polyhydric alcohol), an .alpha., .beta.-unsaturated
polyvalent carboxylic acid, and an acid component (saturated
polyvalent carboxylic acid and aromatic polyvalent carboxylic acid)
according to a known production method. The vinyl ester resin is
not particularly limited unless it hinders the effects of the
present invention. The vinyl ester resin can be produced by a known
method, and commercial products thereof may be also used.
[0078] The thermoplastic resin is not particularly limited unless
it hinders the effects of the present invention. Any of
thermoplastic styrene resins, thermoplastic polyolefin resins,
thermoplastic polyvinyl chloride resins, thermoplastic polyurethane
resins, thermoplastic polyester resins, thermoplastic polyimide
resins and other thermoplastic resins may be used, but
thermoplastic polyolefin resins are preferred. The thermoplastic
polyolefin resin is not particularly limited and examples thereof
include thermoplastic polypropylene resins, thermoplastic
polystyrene resins and thermoplastic
acrylonitrile-butadiene-styrene resins (ABS resin). In addition,
synthetic resins, such as ethylene-propylene rubber (EPDM),
synthetic rubber based on a styrene-butadiene copolymer (SBR), and
nitrile rubber (NBR), can be also used.
[0079] The content ratio of the fiber and the resin in each of the
above-mentioned layers is not particularly limited to specific
values unless the content ratio hinders the effects of the present
invention. The content ratio varies with the kinds of the organic
fiber and the resin, and the dimension of the shaped product. In
order that the shaft may have a desired strength, for example, a
sufficient flexural stiffness, and be so lightweight as to allow
prolonged use, resistant to fracture and excellent in safety and
repairability, the content ratio as a mass ratio is selected from
the ranges of 80:20 to 60:40, preferably 75:25 to 65:35, and more
preferably 70:30 to 67:33. When the amount of the impregnating
resin is too large, an appropriate strength cannot be easily
maintained. When the amount of the impregnating resin is too small,
shaped products cannot be obtained or, if obtained, do not have an
appropriate strength. Here, the term "appropriate strength" means a
strength for achieving the effects of the present invention.
[0080] The specific gravity of the shaft (4) varies with the kinds
of the high-strength organic fiber and the resin to be used, the
content ratio thereof and the like, but is preferably about 1.30 to
1.45, more preferably 1.32 to 1.37, and particularly preferably
1.33 to 1.36.
[0081] The weight and strength of the cane (7) vary with the
thickness of the cane (7), the thickness of the shell (18), the
fiber-resin content ratio in each of the fiber-reinforced resin
layers (31, 32, 33), the thickness of each of the layers, the kind
of the resin, etc. Since high-strength organic fibers have a
smaller specific gravity than that of carbon fibers, by using less
of the carbon-fiber-reinforced-resin layer (32) and more of the
high-strength-organic-fiber-resin layer (31), a lightweight and
strong cane (7) is obtainable. In this case, the specific gravity
of the shaft (4) is not limited to specific values, but is
preferably 1.30 to 1.45. In order that the shaft (4) may have a
sufficient flexural stiffness against a force perpendicular to the
axial direction and be so lightweight as to allow prolonged use,
the specific gravity is more preferably 1.32 to 1.37, and
particularly preferably 1.33 to 1.36.
[0082] In the first embodiment, the grip (1) is in an I shape, and
if needed, a connector (2), a strap (3), etc. may be attached to
any site of the grip (1). Alternatively, in the present invention,
the grip (1) may be in other shapes such as a T shape as mentioned
below. The length and thickness of the grip (1) are appropriately
determined as such dimensions that the user can firmly grasp the
grip (1).
[0083] As shown in FIG. 3, the grip (1) has a hollow-structured
grip body (19) extended upward from the upper end of the shaft (4).
The grip body (19) maybe formed integrally with the shaft (4) by
expanding one end of the shaft (4) into a predetermined shape by,
for example, blow molding, vacuum molding, etc. In this case, since
the cross-section perpendicular to the axis of the grip body (19)
is larger than that of the shaft (4), the grip (1) is easy for the
user to firmly grasp. In addition, since the grip (1) is
hollow-structured, weight saving of the grip (1) can be easily
achieved. Further, since the same fiber-reinforced resin materials
as those of the shaft (4) are used, a strong grip (1) can be
produced at low cost.
[0084] Alternatively, in the present invention, the grip (1) may be
separately formed and fixed to the upper end of the shaft (4) with
an adhesive etc. Further, the grip (1) may be also formed by
coating the outside of any core with resin. In this case, the core
may be hollow structured. These grips (1) can be commercial
products, or produced by a known method. The production method is
not particularly limited and the dimensions such as the length and
diameter of the grip are appropriately determined if needed.
[0085] The resin used for the grip (1) is not particularly limited
unless it hinders the effects of the present invention. Examples
thereof include polyester resins, polyamide resins (for example,
nylons such as nylon 6, 66 nylon and MC nylon), acrylate resins,
ABS resins, polyolefin resins (for example, polypropylene resins,
polyethylene resins, etc.), polybutylene terephthalate resins and
polyethylene terephthalate resins. Fiber-reinforced resins may be
also used. Examples of the material used for the core include
silicone and nylon. In particular, it is preferable that the grip
(1) is formed of, for example, a carbon fiber-reinforced resin and
a high-strength organic fiber-reinforced resin, because such a grip
(1) is lightweight, highly strong and producible at low cost.
[0086] The outer surface of the grip body (19) may be externally
exposed as it is, but preferably the outer surface of the grip body
(19) is in an antislip shape such as uneven patterns, or has an
antislip member (20) attached thereto as shown in FIG. 3 because
such a grip (1) is easy for the user to hold. The antislip member
(20) may be a coating made of synthetic resins such as urethane,
rubber materials, etc. Alternatively, as the antislip member (20),
a tape made of such materials may be attached around the gripper.
Particularly, the latter case is preferable because such an
antislip member (20), after damaged as a result of wear etc., can
be easily replaced by a new antislip member (20).
[0087] As shown in FIGS. 1 and 4, the ferrule (6) is fixed to the
lower end of the shaft (4). The ferrule (6) is formed of a
high-strength organic fiber-reinforced resin and in a so-called
teardrop shape, in which the upper part is truncated conical and
the lower part is spherical. The ferrule (6) has a joint hole (25)
as a recess in the upper end, and the lower end of the shaft (4) is
fitted into the joint hole (25) and fixed thereto.
[0088] Fixation of the ferrule (6) to the shaft (4) may be
performed using adhesives etc. so that the ferrule (6) and the
shaft (4) are inseparable. This is preferable because the ferrule
(6) does not separate from the shaft (4) during use .
Alternatively, separable fixation may be performed by press fit
etc. This case is also preferable because such a ferrule (6), after
worn out, can be easily replaced by a new one.
[0089] It is also preferable that the ferrule (6) is fitted onto
the lower end of the shaft (4) as described above, because the
lower end of this shaft (4) can be protected by the ferrule (6).
Alternatively, in the present invention, for example, a joint part,
which may be in the shape of rod or the like, may be protruded from
the upper end of the ferrule (6), inserted into the lower end of
the shaft (4) and thereby fixed thereto.
[0090] The thickness and length of the ferrule (6) can be
appropriately determined within the range where the effects of the
present invention are not hindered. For example, the outer diameter
of the ferrule (6) is larger than that of the shaft (4) and is such
a dimension to prevent the ferrule from being easily caught in the
grating covers on the road surface, etc. The outer surface of the
ferrule (6) is smoothly curved so that the ferrule is not stuck to
steps on roads, stairs and the like, obstacles, etc.
[0091] The high-strength organic fiber-reinforced resin which
constitutes the ferrule (6) is one obtained by dispersing staple
fibers of a high-strength organic fiber in a synthetic resin. When
the high-strength organic fiber content is too low, the ferrule (6)
does not fully work as a sensor. Conversely, when the content is
excessively high, the fibers cannot be easily dispersed in the
synthetic resin. Therefore, the ratio of the high-strength organic
fiber in the high-strength organic fiber-reinforced resin is
preferably 10 to 60 mass %, and more preferably 20 to 50 mass
%.
[0092] Examples of the high-strength organic fiber include
ultra-high-molecular-weight-polyethylene fibers, wholly-aromatic
polyamide fibers, wholly-aromatic polyester fibers, heterocyclic
high-performance fibers and polyacetal fibers, as is the case with
the high-strength organic fiber which constitutes the shaft (4).
These fibers may be used alone or in a combination of two or more
kinds. Specifically, para-aramid fibers are preferably used and
poly(p-phenylene terephthalamide) fibers are particularly
preferable.
[0093] The dimensions of the high-strength organic fiber dispersed
in the synthetic resin vary with the kinds of the high-strength
organic fiber and the synthetic resin, etc., but preferred is a
high-strength organic fiber with a filament fineness of about 1.1
to 2.3 dtex and with a fiber length of about 2 to 8 mm because such
a high-strength organic fiber can favorably disperse.
[0094] The synthetic resin used for dispersion of the high-strength
organic fiber may be a thermosetting synthetic resin etc., but
thermoplastic synthetic resins are preferable because they enable
easy formation of the ferrule (6) in a predetermined shape. The
thermoplastic synthetic resin is not particularly limited to
specific kinds, but polyamide resins such as 6 nylon, 66 nylon and
MC nylon are preferable because they enable easy dispersion of the
high-strength organic fiber and easy formation of the ferrule (6)
and are excellent in wear resistance etc.
[0095] The high-strength organic fiber-reinforced resin may contain
any fibers such as polyamide fibers, in addition to the
above-mentioned high-strength organic fiber. Further, any additives
for enhancing wear resistance, durability, light resistance, etc.,
bulking agents, colorants, etc. may be contained.
[0096] In the first embodiment, a case where the indicating layer
is covered with a wear-resistant transparent resin layer is
described. However, in the present invention, for example, a
cylindrical glass-fiber-reinforced-resin layer (33b) may be
laminated onto the outside surface of the indicating layer (34),
according to a second embodiment shown in FIG. 5.
[0097] That is to say, according to the second embodiment, the
indicating layer (34) is formed on the outside surface of a second
high-strength-organic-fiber-reinforced-resin layer (31b), and a
second glass-fiber-reinforced-resin layer (33b) is integrally
laminated onto the outside surface of the indicating layer (34).
The second glass-fiber-reinforced-resin layer (33b) is transparent,
and thus the indicating layer (34) can be clearly seen from the
outside. Further, the second glass-fiber-reinforced-resin layer
(33b) is excellent in wear resistance and water resistance, and
thus prevents the indicating layer (34) from getting worn or
getting wet and detached. Unlike the first embodiment, no
wear-resistant transparent resin layer is needed and thus the
corresponding cost can be cut. Other constitutions are the same as
those of the first embodiment and function similarly. Therefore,
descriptions therefor will be omitted.
[0098] In the first embodiment, a straight cane is described.
However, the cane of the present invention may be a folding cane,
for example, as shown in FIGS. 6 and 7.
[0099] According to a third embodiment, as shown in FIG. 6 (a), a
cane (7) has a shaft (4), a grip (1) provided at the upper end of
the shaft (4), and a ferrule (6) fixedly attached to the lower end
of the shaft (4), as is the case with the first embodiment.
However, unlike the first embodiment, the shaft (4) consists of a
plurality of mutually connectable and separable shaft parts (14),
for example, five shaft parts (14), and a cylindrical joint cover
(5) is provided to cover each junction where two shaft parts (14)
are connected to each other. The grip (1) is extended from the
upper end of the top shaft part (14) and formed integrally
therewith.
[0100] As is the case with the shaft (4) of the first embodiment,
the shaft part (14) is in the shape of a hollow cylinder of which
the cross-section perpendicular to the axis is in a circular shape.
In addition, as shown in FIG. 6 (b), the shaft part (14) comprises
a carbon-fiber-reinforced-resin layer (32) and a
high-strength-organic-fiber-reinforced-resin layer (31) integrally
formed on each of the inside and outside surfaces of the
carbon-fiber-reinforced-resin layer (32). Further, on each of the
outer and inner high-strength-organic-fiber-reinforced-resin layers
(31), a glass-fiber-reinforced-resin layer (33) is provided. On the
outside surface of the second glass-fiber-reinforced-resin layer
(33b), a white reflective tape (15) and a red-colored tape (16) are
attached, and the outside surface of each tape is covered with a
wear-resistant transparent resin layer (35).
[0101] As shown in FIGS. 8 and 9, in the shaft parts (14) adjacent
to each other, an inner pipe (9) as a smaller-diameter part is
fixedly secured to a first connecting end (21) of one shaft part
(14), and a rubber cord (8) connecting the shaft parts (14) is
inserted through the inner pipe (9). The protruding length of the
inner pipe (9) protruding outward from the first connecting end
(21) is not limited to specific values as long as the length is
enough for firm connection of the shaft parts (14). For example,
the length is about 30 to 50 mm.
[0102] The material and thickness of the rubber cord (8) are not
particularly limited as long as the rubber cord (8) is so elastic
and stretchy as to allow easy separation and connection of the
shaft parts (14), and known rubber cords can be used.
[0103] The inner pipe (9) has an outer diameter approximately equal
to the inner diameter of the shaft part (14), and can be inserted
into and removed from a second connecting end (22) of the opposite
shaft part (14). According to this embodiment, the inner pipe (9)
is formed separately from the shaft part (14) and one end thereof
is fixed into the first connecting end (21) by press fit, known
adhesives, etc. Alternatively, in the present invention, the
smaller-diameter part may be formed integrally with the connecting
end of the shaft part (14). The material of the inner pipe (9) is
not limited to specific kinds, but the inner pipe (9) preferably
comprises a high-strength-organic-fiber-reinforced-resin layer and
a glass-fiber-reinforced-resin layer as used for the shaft part
(14), and more preferably comprises only a
high-strength-organic-fiber-reinforced-resin layer composed of a
para-aramid fiber and the like . Unlike the shaft part (14), it is
preferable that the inner pipe (9) does not comprise any
carbon-fiber-reinforced-resin layer.
[0104] One end of the joint cover (5) is fitted onto the first
connecting end (21) and fixed thereto. The joint cover (5) is not
limited to specific shapes as long as it is cylindrical and can
connect the shaft parts (14). However, it is preferable that the
outer surface of the joint cover (5) is so smooth as not to be
caught in other objects. For example, the joint cover (5) is in a
cylindrical shape with the diameter slightly decreasing toward both
ends, and has a ring-shaped stopper (23) inside centered on the
length of the joint cover. The rubber cord (8) penetrates the
stopper (23). The first connecting end (21) is inserted from one
end of the joint cover (5) until it abuts against the stopper (23),
and is firmly fixed by press fit, known adhesives, etc.
[0105] The other end of the joint cover (5) faces and is open for
the second connecting end (22), and has an inlet (24) therein. By
inserting the second connecting end (22) into the inlet (24), the
shaft parts (14) are connected to each other, and by removing the
second connecting end (22) from the inlet (24), the shaft parts
(14) are separated from each other.
[0106] The inlet (24) has a tapered part (10) with the diameter
gradually decreasing inward from the outer end, and a straight part
(11) having a predetermined inner diameter and extended further
inward from the inner end of the tapered part (10) to the stopper
(23). The inner diameter of the straight part (11) is determined as
such a dimension that the inner surface of the straight part (11)
can tightly press the outer surface of the second connecting end
(22) without any backlash.
[0107] The length of the joint cover (5) is not limited to specific
values and can be appropriately determined within the range where
the effects of the present invention are not hindered. The length
of the tapered part (10) is preferably larger than that of the
straight part (11). In this case, the axial alignment of the shaft
parts (14) to be connected is easy and the second connecting end
(22) can be smoothly guided. Specifically, the tapered
part-straight part ratio is preferably about 5 to 2:1. The length
of the straight part (11) is not limited to specific values as long
as the length neither allows any backlash in the junction nor
hinders any effect of the present invention. However, because
connection and separation cannot be easily performed in the case of
an excessively long straight part, the length of the straight part
(11) is preferably about 20 to 80% of the outer diameter of the
shaft (4) in general.
[0108] The joint cover (5) is produced from, for example,
polyamides such as nylon 6. As long as the joint cover (5) can
firmly hold the junction and effects of the present invention are
not hindered, the material thereof is not limited to specific
kinds. Specifically, for example, thermosetting resins such as
epoxy resins, unsaturated polyester resins and vinyl ester resins
may be used. In addition, thermoplastic resins such as polyester
resins, polyamide resins (for example, nylons such as nylon 6, 66
nylon and MC nylon), acrylate resins, ABS resins, polyolefin resins
(for example, polypropylene resins, polyethylene resins, etc.),
polybutylene terephthalate resins and polyethylene terephthalate
resins may be used. Further, materials having rubber elasticity,
such as synthetic rubbers and elastomers, may be used. The joint
cover (5) can be produced by a known method. In the production,
known additives, pigments, etc. may be appropriately added if
needed, and fiber-reinforced resins may be used. Also, coloring
etc. may be performed after the production.
[0109] After the second connecting end (22) is inserted into the
inlet (24) of the joint cover (5), the second connecting end (22)
is smoothly guided by the tapered part (10), passes along the
straight part (11) and then abuts against the stopper (23). In this
way, connection as shown in FIG. 9 is achieved. In this connection,
the outer surface of the second connecting end (22) is tightly
pressed by the inner surface of the straight part (11), and thus no
backlash is allowed.
[0110] The above constitution prevents stress from concentrating on
specific parts of the cane (7), such as the above-described
connecting ends, and enhances the mechanical strength of the
junctions, on which stress tends to concentrate, by sufficient
reinforcement with the external joint covers (5). Therefore, the
cane (7) has less risk of breaking due to such a stress
concentration and less risk of the user's falling, can be safely
used, and thus is preferable. Further, since there is no backlash,
the connecting ends are prevented from early wear-out due to mutual
friction at the time of connection/separation, and therefore the
durability of the cane (7) is increased. Further, the axis of the
cane (7) does not bend during use, and thus the user can use the
cane with a sense of security. For the shaft parts (14), special
structures such as screw clamps in connecting ends are not needed
since only insertion/removal of the connecting ends and the
smaller-diameter part (9) provided thereon are needed at the time
of connection/separation. Therefore, the shaft parts (14) have a
simple structure, can be produced at low cost, allow easy
connection/separation, and thus are preferable.
[0111] In the third embodiment, one end of the joint cover (5) is
fixed to the first connecting end (21), and the second connecting
end (22) can be inserted into and removed from the other end of the
joint cover (5). Alternatively, in the present invention, it is
possible that one end of the joint cover (5) is fixed to the second
connecting end (22) of the shaft part (14) not provided with a
smaller-diameter part, and that the first connecting end (21) of
the opposite shaft part (14) provided with a smaller-diameter part
can be inserted into and removed from the other end of the joint
cover (5).
[0112] According to the third embodiment, the ferrule (6) is a
standard type, that is, in a cylindrical shape with a smoothly
curved surface in the lower part. The upper part has a curved
surface that has a diameter gradually decreasing toward the upper
end and is continued to the outer surface of the shaft (4). As is
the case with the first embodiment, the ferrule (6) is formed of a
high-strength organic fiber-reinforced resin and has a joint hole
(25) as a recess in the upper end, and the lower end of the shaft
(4) is fitted into the joint hole (25) and fixed thereto. Other
constitutions, such as the grip (1), are the same as those of the
first embodiment and function similarly. Therefore, descriptions
therefor will be omitted.
[0113] In the above embodiments, canes (7) with a so-called
I-shaped grip (1) are described. However, the cane of the present
invention may have a grip (1) of other shapes such as modified
example 1 shown in FIG. 10. For example, FIG. 10 (a) shows a cane
(7) provided with a so-called T-shaped grip (1), FIG. 10 (b) shows
a cane (7) provided with a so-called L-shaped grip (1), and in both
cases, the grip (1) is extended from the upper end of the shaft
(4).
[0114] In the first embodiment, a teardrop type ferrule is used,
and in the third embodiment, a standard type ferrule is used.
However, the ferrule (6) used for the present invention is not
limited to specific shapes unless the use as a cane is hindered.
For example, the above standard type ferrule may be used in a
straight cane as illustrated in the first embodiment, and the above
teardrop type ferrule may be used in a folding cane as illustrated
in the third embodiment. In addition, for example, like modified
example 2 shown in FIG. 11, the above standard type ferrule can be
a standard type ferrule (6) which has a shoulder and has a smaller
diameter in the upper part to reduce the risk of being caught in
other objects.
EXAMPLES
[0115] Hereinafter, the present invention will be illustrated in
more detail by examples and comparative examples, but is not
limited to the examples below.
Example 1
[0116] As a high-strength organic fiber, a poly(p-phenylene
terephthalamide) fiber, KEVLAR K-29 1670 dtx (manufactured by DU
PONT-TORAY CO., LTD.) was used. From this organic fiber, a
unidirectional (UD) sheet with a fiber areal weight of 73 g/m.sup.2
was prepared, and the sheet was impregnated with an epoxy resin by
a hot melt method in such a manner that the fiber-resin content
ratio might be 67:33. In this way, a high-strength organic fiber
prepreg with a fiber areal weight of 110 g/m.sup.2 was obtained. As
a carbon fiber prepreg, TORAYCA (registered trademark) prepregs
(type: 9052S-17 and 3252S-05, manufactured by Toray Industries,
Inc.) were used. Each of these prepregs is a carbon fiber prepreg
with a fiber areal weight of 330 g/m.sup.2 and is produced by
impregnating a UD sheet with a fiber areal weight of 220 g/m.sup.2
with an epoxy resin in such a manner that the fiber-resin content
ratio may be 67:33.
[0117] As a glass fiber, a glass fabric, WPA-240D (manufactured by
Nitto Boseki Co., Ltd.), which is a UD sheet with a fiber areal
weight of 100 g/m.sup.2, was used, and the glass fabric was
impregnated with an epoxy resin by a hot melt method in such a
manner that the fiber-resin content ratio might be 67:33. In this
way, a glass fiber prepreg with a fiber areal weight of 150
g/m.sup.2 was obtained.
[0118] Next, one layer of the glass fiber prepreg as the innermost
layer, three layers of the high-strength organic fiber prepreg, one
layer of the carbon fiber prepreg, two layers of the high-strength
organic fiber prepreg, and one layer of the glass fiber prepreg
were laminated in this order, integrated and cured with heat.
Around the surface of the cured product, a reflective tape was
attached and a 0.06-mm-thick HIMILAN film (trade name, manufactured
by DU PONT-MITSUI POLYCHEMICALS) as a wear-resistant transparent
resin film was laminated to cover the tape. In this way, a
cylindrical body of Example 1 was obtained.
Comparative Example 1
[0119] According to the procedures of Example 1 except using the
above-mentioned carbon fiber prepreg instead of the high-strength
organic fiber prepreg and the glass fiber prepreg of Example 1, a
cylindrical body of Comparative Example 1 was obtained.
Comparative Example 2
[0120] According to the procedures of Example 1 except using the
above-mentioned high-strength organic fiber prepreg instead of the
carbon fiber prepreg and the glass fiber prepreg of Example 1, a
cylindrical body of Comparative Example 2 was obtained.
[0121] Regarding each of the obtained cylindrical bodies, the outer
diameter was 12 mm and the cross-sectional area ratio of the hollow
and the shell was 67:33.
[0122] Next, these cylindrical bodies were measured for stiffness
(flexural property), impact resistance, safety and on-site
repairability, and the respective characteristic values were
determined. The measurement was performed according to the
following methods.
<Stiffness (Flexural Property)>
[0123] Each cylindrical body in the above-mentioned Example and
Comparative Examples was supported by two fulcrum points the
distance between which was 780 mm, and a 3-kg weight was hooked on
the cylindrical body in the middle between the fulcrum points and
left to stand for 10 seconds. The degree (mm) that the cylindrical
body bent in response to the weight was measured.
<Impact Resistance>
[0124] A 30-cm piece was cut from each cylindrical body in Example
and Comparative Examples and used as a sample. According to the
three point flexural test specified in JIS K 7055:1995 (Testing
method for flexural properties of glass fiber-reinforced plastics),
using a Drop Weight Impact Tester (trade name: Dynatup (registered
trademark) 9210, manufactured by Instron), the sample was fixed by
two fulcrum points the distance between which was 105 mm, and given
an impact force of 110J by use of an indenter 22 mm in diameter.
The fracture condition, the absorbed energy, etc. of each sample
were determined.
[0125] The evaluation criteria for the fracture condition are as
follows.
A: Not fractured B: Partially fractured C: Easily and completely
fractured
<Safety>
[0126] After the impact resistance test, the safety was evaluated
based on the presence or absence of spiky fibers projected from the
impact site of each cylindrical body.
[0127] The evaluation criteria for the safety are as follows.
A: There were no spiky fibers projected and sufficient safety was
confirmed. B: There were a few spiky fibers projected. C: There
were spiky fibers projected and they might get stuck in the
hand.
<On-Site Repairability>
[0128] After the impact resistance test, the fractured or damaged
site was repaired by use of an emergency repair kit for domestic
white canes (trade name: YATSUHASHI-KUN; product number: 39032)
distributed by the Tool Sales Division of Japan Braille Library,
and the on-site repairability was evaluated based on whether the
repaired cylindrical body was usable as a cane shaft. This
emergency repair kit (26) contains one pair of semicylindrical
supporting plates (13), for example, as shown in FIG. 12. Repair of
a fractured shaft (4) by use of this emergency repair kit (26) is
performed as follows. The release tape of a double-sided tape (12)
stuck on the back of each supporting plate (13) is stripped off,
the two supporting plates (13) are attached onto the fractured
shaft in such a manner that the fracture site of the shaft (4) is
centered on the length of each supporting plate and is sandwiched
in between the supporting plates, and accessory reflective tapes
(15) are attached over the upper and lower ends of the supporting
plates (13) to firmly fix the supporting plates to the cylindrical
body. In this way, the fractured shaft comes into the state as
shown in FIG. 13. The evaluation criteria of the on-site
repairability are as follows.
A: After impact was given, simple repair on site reproduced a
usable cane. C: After impact was given, simple repair on site was
not applicable and did not reproduce a usable cane.
[0129] The measurement results of the above-mentioned
characteristic values are as shown in Measurement Result Comparison
Table 1 in FIG. 14.
[0130] As is clear from the measurement results, Comparative
Example 1 formed of only a carbon-fiber-reinforced-resin layer had
a high stiffness, but was not enough in impact resistance against a
force in a direction perpendicular to the axis of the cylindrical
body. Also, at the time of impact, Comparative Example 1 fractured
with spiky fibers projected, and thus was not excellent in safety
or on-site repairability. Comparative Example 2 formed of only a
high-strength-organic-fiber-reinforced-resin layer had an excellent
impact resistance and did not fracture at the time of impact, and
thus was excellent in safety and on-site repairability. However,
the flexural degree was high when the load was applied in a
direction perpendicular to the axial direction, and thus the
stiffness was low.
[0131] By contrast, Example 1 of the present invention was more
excellent in stiffness than Comparative Example 2. In addition,
Example 1 bent only slightly at the time of impact and thus was
excellent in impact resistance against a force in a direction
perpendicular to the axis of the cylindrical body. Moreover,
Example 1 did not allow spiky fibers to be projected from the
impact site and thus was excellent in safety, and did not fracture
and thus was also excellent in on-site repairability.
[0132] Example 1 of the present invention, which comprises a
glass-fiber-reinforced-resin layer inside, is excellent in wear
resistance of the inner surface unlike Comparative Example 2, which
comprises only layers made of a high-strength organic fiber
prepreg. For example, in the case of a folding cane having a rubber
cord arranged inside its shaft, the shaft ends are prevented from
early wear-out due to the friction against the rubber cord.
[0133] Since Example 1 had a wear-resistant transparent resin film
laminated to cover a reflective tape attached around the outer
surface of the cylindrical body, it was expected that Example 1
would be much more excellent in wear resistance of the outer
surface and thus could be more favorably prevented from wear-out of
the reflective tape, as compared with conventional products without
the film. For confirmation of these effects, the wear resistance of
the outer surface was measured according to the following
method.
<Wear Resistance of Outer Surface>
[0134] An abrasive cloth sheet 25 mm in width and 300 mm in length
(grain size: #240, manufactured by Noritake Coated Abrasive Co.,
Ltd.) was used. As shown in FIG. 15, the shaft (4) was kept in a
horizontal position, the abrasive cloth sheet (36) was horizontally
and vertically placed in the 90-degree direction to the axis of the
shaft (4) in such a manner that the sheet was in contact with a
quadrant part (90-degree part) of the shaft (4) surrounded by the
upper horizontal plane and the vertical plane. Under the condition
that a 330-g weight (37) was hung on the lower end of the upright
portion of the abrasive cloth sheet (36), the abrasive cloth sheet
(36) was moved 200 mm against the shaft at the speed of 2 seconds
per stroke to abrade the surface of the shaft (4).
[0135] As a result of the measurement, in the case where the
reflective tape was externally exposed without the wear-resistant
transparent resin film, the superficial reflective tape was worn
out in five strokes and the glass-fiber-reinforced-resin layer
under the tape was exposed. By contrast, in the case of Example 1
of the present invention, which had a wear-resistant transparent
resin film laminated onto the outside surface of the reflective
tape, the reflective tape was not worn out at all even after 100
strokes.
[0136] Next, a teardrop type ferrule (6) was attached to the
cylindrical body of Example 1 and the resulting product was
regarded as Example 2. For examination of the usage characteristics
of this ferrule (6), the information transmission performance and
the manipulability were tested by use of the actual road surfaces
shown in FIG. 16, and the antisticking property (smooth mobility
over the uneven surface) was tested by use of antislip parts of
stairs, gaps on the road surface, etc. For the test, three kinds of
road surfaces were used, that is, an asphalt pavement surface shown
in FIG. 16 (a), a concrete pavement surface arranged with gravels
shown in FIG. 16 (b), and a concrete pavement surface with a tiled
pattern shown in FIG. 16 (c).
[0137] From a high-strength-organic-fiber-reinforced-resin
material, the above-mentioned ferrule (6) was formed in a teardrop
shape 26.1 mm in maximum outer diameter and 40.4 mm in length.
Then, the lower end of the shaft (4) 12.5 mm in outer diameter was
inserted into a joint hole (25) 13 mm in inner diameter formed in
the upper end of this ferrule (6) and fixed thereto with an
adhesive. The high-strength-organic-fiber-reinforced-resin material
was one in which staple fibers of a poly(p-phenylene
terephthalamide) fiber were dispersed in a polyamide resin (Nylon
6), and was obtained by cutting 1.7-dtex filaments of the
poly(p-phenylene terephthalamide) fiber into 6-mm pieces, and then
dispersing the pieces in the polyamide resin. The
high-strength-organic-fiber-reinforced-resin material contained 70
mass % of the polyamide resin and 30 mass % of the poly(p-phenylene
terephthalamide) fiber.
<Information Transmission Performance>
[0138] It was tested whether the cane is capable of transmitting
information on road surface conditions such as unevenness and
smoothness to the user. In the case where the user examining the
road surface could detect the differences of the road surfaces, the
subject cane was evaluated as "good," and in the case where the
user could not detect such differences, the subject cane was
evaluated as "poor."
<Manipulability>
[0139] The burden given to the hand and wrist when the user swung
around the cane or poked the road surface etc. with the cane was
measured. In addition, the sound level was measured when the
ferrule touched the road surface. In the case where the subject
cane in use gave less burden to the hand and wrist and did not make
a loud sound, the subject cane was evaluated as "good," and in the
case where the burden was heavy and the sound was loud, the subject
cane was evaluated as "poor."
<Antisticking Property>
[0140] It was tested whether or not the subject cane would be stuck
to or caught in antislip parts of stairs, gaps on the road surface,
etc. In the case where the subject cane was not stuck or caught,
the subject cane was evaluated as "good," and in the case where the
subject cane was stuck or caught, the subject cane was evaluated as
"poor."
[0141] Regarding the above-mentioned usage characteristics, the
measurement results in comparison with conventional ferrules for
canes are shown in Measurement Result Comparison Table 2 in FIG.
6.
[0142] Each conventional ferrule used for the comparison was made
of a polyamide resin (PA6), a standard type was regarded as
Comparative Example 3, a teardrop type was regarded as Comparative
Example 4, and a palm tip type was regarded as Comparative Example
5. The palm tip type as Comparative Example 5 was one having an
elastic member between the shaft and the grounding part of the
ferrule, as described in, for example, the WO 07/058180 pamphlet.
Specifically, the one having an elastic member made of chloroprene
rubber between the shaft and the grounding part made of a polyamide
resin was used.
[0143] As is clear from the results of the above-mentioned
measurement, Comparative Examples 3 to 5 did not enable easy
recognition of the kind of the road surface, and thus were poor in
information transmission performance. By contrast, Example 2 of the
present invention enabled easy recognition of the three kinds of
road surfaces, and thus was extremely excellent in information
transmission performance.
[0144] Specifically, while using any of Comparative Examples 3 to
5, the user had a feel that the ferrule stuck to the road surface
as if writing letters with a crayon, and thus could not easily
detect the kind of the road surface. By contrast, while using
Example 2 of the present invention, the user had a feel that the
ferrule lightly touched the road surface and slightly bounced back
therefrom as if writing letters with a pencil, and the feel clearly
varied with the kind of the road surface.
[0145] Further, Example 2 of the present invention was more
excellent in manipulability than not only Comparative Example 4 but
also Comparative Examples 3 and 5.
[0146] Specifically, while manipulating Comparative Example 4, the
user was given a heavy burden to the hand and wrist, and thus the
manipulability was poor. Regarding Comparative Examples 3 and 5,
the burden was lighter than that of Comparative Example 4, and thus
the manipulability was favorable. By contrast, regarding Example 2
of the present invention, the ferrule favorably reacted against the
road surface to be examined, and thus the user was less required to
excessively swing around the cane or poke about therewith, and was
given further less burden to the hand and wrist than that in
Comparative Examples 3 and 5. In addition, the sound generated when
the user hit the road surface with the cane was not so loud, and
thus the manipulability was extremely favorable.
[0147] Next, the wear resistance of the ferrule (6) was measured.
The test product was made of the
high-strength-organic-fiber-reinforced-resin material used for the
standard type ferrule adopted in the third embodiment and was
regarded as Example 3. This
high-strength-organic-fiber-reinforced-resin material consists of a
polyamide resin (66 nylon) reinforced with staple fibers of a
poly(p-phenylene terephthalamide) fiber, which is a high-strength
organic fiber. The content ratio of the high-strength organic fiber
to the fiber-reinforced resin is 30 mass %. As the comparative test
products, a molded product made of a polypropylene resin (PP) alone
and a molded product made of a polyamide resin (Nylon 6) alone were
used and regarded as Comparative Examples 6 and 7,
respectively.
[0148] The test method was in accordance with method A specified in
JIS K 7218:1986 (Testing methods for sliding wear resistance of
plastics) and the following conditions were adopted.
Test piece: ring (hollow cylindrical shape) Opponent material:
SUS304 ring (hollow cylindrical shape) The surface roughness was
adjusted by finishing with #1000 abrasive paper (0.1 .mu.mRa>).
Measurement item: wear mass Measurement conditions
[0149] Sliding speed: 500 mm/second
[0150] Friction area: 2 cm.sup.2
[0151] Test load: 100 N
[0152] Test time: 100 minutes (3 km)
[0153] Number of measurement: n=1
Laboratory environment: temperature: 23.+-.2.degree. C., humidity:
50.+-.10% RH Measuring device: rotary tribometer for kinetic
friction and wear tests, IIIT-2000-5000N model (manufactured by
Takachihoseiki Co., LTD.)
[0154] The test results are as shown in Measurement Result
Comparison Table 3 in FIG. 18.
[0155] As is clear from the test results, Comparative Example 6
formed of polypropylene resin was worn out at the early stage, and
Comparative Example 7 formed of polyamide resin showed a large wear
mass and was frictionally heated, resulting in resin melting in the
middle of the test. By contrast, since the high-strength organic
fiber-reinforced resin was used in Example 3 of the present
invention, constant wear was maintained till the end of the test
and even the constant wear mass was slight. Accordingly, it was
confirmed that the ferrule of the present invention formed of a
high-strength organic fiber-reinforced resin is excellent in wear
resistance.
[0156] The canes and the cylindrical bodies used therefor described
in the above-mentioned embodiments are illustrated in order to
embody the technical ideas of the present invention. Therefore, the
shape, the dimension, the number of layers, etc. of each component
are not limited to those specified in these embodiments, and
various modifications can be made within the scope of the
claims.
[0157] For example, the shaft and the grip are integrally formed in
the first embodiment, but in the present invention, they may be
separately formed and fixed to each other.
[0158] Regarding the folding cane of the third embodiment, a case
where joint covers are provided at all the junctions of shaft parts
is described. However, in the present invention, the joint cover
may be omitted at any junction. For example, the joint cover may be
provided only at the lowermost junction, which is prone to break,
not at the other junctions.
[0159] In each of the above-mentioned embodiments, the indicating
layers are a reflective tape and a colored tape. However, in the
present invention, other kinds of indicating layers may be used and
these indicating layers may be omitted.
[0160] In the above-mentioned embodiments, a poly(p-phenylene
terephthalamide) fiber is used as a high-strength organic fiber,
but it will be understood that other kinds of high-strength organic
fibers may be also used in the present invention.
INDUSTRIAL APPLICABILITY
[0161] The cane of the present invention is useful as a cane for
sports such as mountain climbing and skiing or for ordinary
walking, as well as a white cane for the visually disabled.
Further, the cane of the present invention gives less physical
burden to the user, is greatly beneficial in particular to the
elderly, juniors and the visually disabled, and is also helpful to
facilitate self-support, to increase social participation of people
in need of nursing care, and to improve labor productivity.
REFERENCE SIGNS LIST
[0162] 1 . . . Grip [0163] 4 . . . Shaft [0164] 5 . . . Joint cover
[0165] 6 . . . Ferrule [0166] 7 . . . Cane [0167] 9 . . .
Smaller-diameter part (inner pipe) [0168] 14 . . . Shaft part
[0169] 17 . . . Hollow [0170] 18 . . . Shell [0171] 19 . . . Grip
body [0172] 20 . . . Antislip member [0173] 21 . . . First
connecting end [0174] 22 . . . Second connecting end [0175] 31 . .
. High-strength-organic-fiber-reinforced-resin layer [0176] 31a . .
. First high-strength-organic-fiber-reinforced-resin layer [0177]
31b . . . Second high-strength-organic-fiber-reinforced-resin layer
[0178] 32 . . . Carbon-fiber-reinforced-resin layer [0179] 33 . . .
Glass-fiber-reinforced-resin layer [0180] 33a . . . First
glass-fiber-reinforced-resin layer [0181] 33b . . . Second
glass-fiber-reinforced-resin layer [0182] 34 . . . Indicating layer
[0183] 35 . . . Wear-resistant transparent resin layer
* * * * *