U.S. patent application number 15/144802 was filed with the patent office on 2016-08-25 for sewn ball and manufacturing method thereof.
This patent application is currently assigned to TongCheng HuiLong Sports articles Co.Ltd.. The applicant listed for this patent is TongCheng HuiLong Sports articles Co.Ltd.. Invention is credited to Yadong Lu.
Application Number | 20160243409 15/144802 |
Document ID | / |
Family ID | 56116215 |
Filed Date | 2016-08-25 |
United States Patent
Application |
20160243409 |
Kind Code |
A1 |
Lu; Yadong |
August 25, 2016 |
Sewn ball and manufacturing method thereof
Abstract
A sewn ball includes an inner tube and a housing. The inner tube
includes a tube body, a yarn layer and a rubber layer, wherein the
yarn layer is attached to an external surface of the tube body, the
rubber layer is attached to an external surface of the yarn layer
and is then vulcanized, in such a manner that a rubber raw material
of the rubber layer permeates through yarn gaps of the yarn layer,
so as to integrate the tube body, the yarn layer with the rubber
layer. The housing wraps around and is attached to the inner tube.
The sewn ball provided by the present invention has excellent
jumping ability, high strength, good durability, small
circumferential error, and excellent balance and flight
stability.
Inventors: |
Lu; Yadong; (Xianning,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TongCheng HuiLong Sports articles Co.Ltd. |
Xianning |
|
CN |
|
|
Assignee: |
TongCheng HuiLong Sports articles
Co.Ltd.
|
Family ID: |
56116215 |
Appl. No.: |
15/144802 |
Filed: |
May 2, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A63B 41/08 20130101;
A63B 45/00 20130101; A63B 41/02 20130101; A63B 2041/005
20130101 |
International
Class: |
A63B 41/08 20060101
A63B041/08; A63B 45/00 20060101 A63B045/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 18, 2016 |
CN |
201610156079.6 |
Claims
1. A sewn ball, comprising an inner tube and a housing, wherein the
inner tube comprises a tube body, a yarn layer and a rubber layer;
the yarn layer is attached to an external surface of the tube body,
the rubber layer is attached to an external surface of the yarn
layer and is then vulcanized, in such a manner that a rubber raw
material of the rubber layer permeates through yarn gaps of the
yarn layer, so as to integrate the tube body, the yarn layer with
the rubber layer; the housing wraps around and is attached to the
inner tube.
2. The sewn ball, as recited in claim 1, wherein the sewn ball is a
sewn football or a sewn volleyball.
3. The sewn ball, as recited in claim 1, wherein a balance plate is
provided on the inner tube and located at a position where is
coaxially aligned with a gas nozzle and symmetrical to a spherical
center.
4. The sewn ball, as recited in claim 1, wherein a circumferential
error of the sewn ball is less than 2 mm, and a thickness of the
yarn layer is 0.1-1 mm.
5. The sewn ball, as recited in claim 1, wherein the housing
comprises 6-32 leather pieces.
6. The sewn ball, as recited in claim 1, wherein the tube body is a
double layer tube body comprising an internal layer body and an
external layer body tightly attached to the internal layer
body.
7. The sewn ball, as recited in claim 1, wherein the rubber layer
is an ordinary rubber layer or a foamed rubber layer; after
vulcanization, an external surface of the rubber layer forms a
layer of dense rubber membrane.
8. The sewn ball, as recited in claim 1, wherein the rubber layer
comprises an internal layer rubber, a yarn reinforcement layer and
an external layer rubber, wherein the internal layer rubber is
attached to an interior of the yarn layer, the yarn reinforcement
layer is attached to an external surface of the internal layer
rubber, the external layer rubber is attached to an external
surface of the yarn reinforcement layer.
9. A manufacturing method of a sewn ball, comprising steps of: (1)
cutting a leather into a plurality of leather pieces with a leather
cutter, and then sewing the leather pieces according to a spherical
surface leather piece arrangement order to form a housing, and
meanwhile, leaving 1-4 edges of the housing as an opening; (2)
preparing an inner tube, comprising: (2A) preparing a tube body
fittingly with a roundness of a ball; (2B) preparing a yarn ball
comprising injecting gas into the tube body, and measuring a
periphery thereof, winding yarns around an external surface of the
tube body with a yarn winding machine; (2C) preparing a rubber raw
material ball by attaching a rubber raw material to an external
surface of the yarn ball; and (2D) preparing a vulcanizing inner
tube comprising steps of: putting the rubber raw material ball
prepared by the step (2C) into a vulcanizing mould, communicating a
gas injection needle on the vulcanizing mould with a gas nozzle of
the rubber raw material ball and pressurizing, heating and
vulcanizing with a vulcanizing temperature of 95-160.degree. C., a
pressure of 3-10 kg/cm.sup.2 and a vulcanizing time of 4-10 min,
permeating the rubber raw material through yarn gaps after
vulcanization, and vulcanizing mould unloading for obtaining the
inner tube; (3) coating or not coating a binder on a surface of the
inner tube obtained by the step (2); (4) coating a glue around an
air hole of the housing obtained by the step (1) and the gas nozzle
of the inner tube obtained by the step (2); (5) putting the inner
tube into the housing from the opening thereof, cementing after
corresponding the gas nozzle of the inner tube to the air hole of
the housing, and sewing the opening of the housing to prepare a
pretreated sewn ball; and (6) injecting gas into the pretreated
sewn ball obtained by the step (5) to form a round ball, putting
the round ball into a reshaping mould, pressurizing and reshaping
with a pressure of 3-10 kg/cm.sup.2, a time of 1-8 min, and a mould
temperature of 30-70.degree. C. for attaching the housing to the
surface of the inner tube, and cleaning a surface of the housing,
thereby obtaining the sewn ball, wherein a circumferential error of
the sewn ball is less than 2 mm.
10. The manufacturing method of the sewn ball, as recited in claim
9, wherein after the rubber raw material ball is prepared in the
step (2C), a balance plate is attached to a position where is
coaxially aligned with the gas nozzle and symmetrical to a
spherical center on the rubber raw material ball, and then the step
(2D) is processed.
11. The manufacturing method of the sewn ball, as recited in claim
9, wherein the sewn ball comprises an inner tube and a housing,
wherein the inner tube comprises a tube body, a yarn layer and a
rubber layer; the yarn layer is attached to an external surface of
the tube body, the rubber layer is attached to an external surface
of the yarn layer and is then vulcanized, in such a manner that a
rubber raw material of the rubber layer permeates through yarn gaps
of the yarn layer, so as to integrate the tube body, the yarn layer
with the rubber layer; the housing wraps around and is attached to
the inner tube.
12. The manufacturing method of the sewn ball, as recited in claim
9, wherein the sewn ball is a sewn football or a sewn
volleyball.
13. The manufacturing method of the sewn ball, as recited in claim
9, wherein a circumferential error of the sewn ball is less than 2
mm, and a thickness of the yarn layer is 0.1-1 mm.
14. The manufacturing method of the sewn ball, as recited in claim
9, wherein the housing comprises 6-32 leather pieces.
15. The manufacturing method of the sewn ball, as recited in claim
9, wherein the tube body is a double layer tube body comprising an
internal layer body and an external layer body tightly attached to
the internal layer body.
16. The manufacturing method of the sewn ball, as recited in claim
9, wherein the rubber layer is an ordinary rubber layer or a foamed
rubber layer; after vulcanization, an external surface of the
rubber layer forms a layer of dense rubber membrane.
17. The manufacturing method of the sewn ball, as recited in claim
9, wherein the rubber layer comprises an internal layer rubber, a
yarn reinforcement layer and an external layer rubber, wherein the
internal layer rubber is attached to an interior of the yarn layer,
the yarn reinforcement layer is attached to an external surface of
the internal layer rubber, the external layer rubber is attached to
an external surface of the yarn reinforcement layer.
Description
CROSS REFERENCE OF RELATED APPLICATION
[0001] The present invention claims priority under 35 U.S.C.
119(a-d) to CN 201610156079.6, filed Mar. 18, 2016.
BACKGROUND OF THE PRESENT INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a technical field of sports
goods, and more particularly to a sewn ball and a manufacturing
method thereof.
[0004] 2. Description of Related Arts
[0005] The inner tube of conventional sewn balls, such as sewn
footballs and sewn volleyballs, includes three structural forms as
follows: (1) rubber inner tube; (2) yarn tire by winding a layer of
yarn around the exterior of the rubber inner tube; and (3) cloth
tire by attaching a layer of cloth to the exterior of the rubber
inner tube. Shortcomings of the above three structural forms are
respectively described as below.
[0006] Shortcomings of the first structure are: firstly, due to the
flexibility, the rubber inner tube is able to expand unlimitedly
without forming while being injected with the gas, and the
expanding force is directly applied to the housing, so that the
housing easily bursts to expose seaming lines till the ball finally
bursts; secondly, the rubber inner tube has poor gas tightness,
after a long period, the sufficient gas gradually slowly leaks, so
that the gas always needs to be added, thereby it is not convenient
for usage; thirdly, the gas nozzle of the rubber inner tube is
located at one side thereof, the gas nozzle and a circle of the
yarn reinforcement layer, which is around the gas nozzle and
attached to the rubber inner tube, allow the center of gravity of
the whole ball to trend to the side where the gas nozzle is
located, so that the center of gravity of the ball is unbalanced,
which leads to the unstable flight.
[0007] Shortcomings of the second structure are: a layer of yarn is
wound around the exterior of the rubber inner tube, and the basic
circumference of the rubber inner tube is restrained with the yarn
to set the shape of the rubber inner tube and increase the striking
breaking strength of the ball. However, after the yarn tire is
injected with the gas, the whole ball is hard and easily hits
hands. Simultaneously, once the whole ball is hard, the flight
balance becomes poor when the ball flies. Accordingly, the hard
ball not only has poor rebound, but also results in poor sense
control force of the player. Furthermore, during the manufacturing
process of the yarn tire, the yarn is mechanically wound around the
rubber inner tube, and however, the mechanical wound yarn tire is
unable to ensure the circumferential error of the ball, the
circumferential error generally reaches 3-5 mm, which leads to poor
balance and jumping ability, and unstable flight of the ball.
[0008] Shortcomings of the third structure are: a layer of cloth is
attached to the exterior of the rubber inner tube to form the cloth
tire. For example, Chinese Patent No. 201020150442.1 discloses a
football, which includes a sheath and a liner, wherein a layer of
cloth is located between the sheath and the liner. Compared with
the yarn tire, the cloth tire has soft surface after being injected
with the gas. However, the cloth tire, obtained by replacing the
yarn with the cloth, has poor forming, low striking breaking
strength of the ball, and large circumferential error (in
generally, which reaches 3-5 mm), so that it has poor jumping
ability, poor balance, unstable flight, insufficiently strength and
poor durability.
[0009] Therefore, the rubber inner tube is able to continuously
expand with the increase of the internal gas, so that it is unable
to control the ball to achieve the determined shape and size, thus
the gas leakage easily appears. In spite that the yarn tire is able
to avoid a burst during tire inflation and plays a role in forming,
due to the ball is mechanically wound with yarns, the yarns are
always unevenly wound, so that the ball is unable to be completely
controlled to achieve the determined shape. Similarly, in spite
that the cloth tire is able to play a role in forming, the cloth
has various latitude and longitude lines, which leads to uneven
tensions, so that it is unable to completely control the ball to
achieve the determined shape.
[0010] During the manufacturing process of the conventional sewn
footballs, the housing thereof comprises 20 regularly hexagonal
leather pieces and 12 regularly pentagonal leather pieces.
Accordingly, these leather pieces need to be attached or sewn one
by one, and there are at least 32 attaching or sewing actions. More
attaching or sewing actions are, and lower productive efficiency
is. Furthermore, the attaching or sewing is large in difficulties
and low in accuracy, so that the manufactured ball is bad in hand
feeling and the circumferential error is unable to be ensured. To
reduce the leather pieces of the housing for decreasing the
difficulties of the attaching or sewing, Chinese Patent No.
201320488758.5 discloses a ten-attaching/sewing-leather-piece
sports football, which comprises an external leather forming a
spherical surface, wherein the external leather comprises two
integrally formed four-leather-units and eight integrally formed
three-leather-units; every integrally formed four-leather-unit
comprises two regularly hexagonal leather pieces and two regularly
pentagonal leather pieces, the two regularly hexagonal leather
pieces and the two regularly pentagonal leather pieces are arranged
in a straight line, the two regularly hexagonal leather pieces are
located at a middle of the straight line, the two regularly
pentagonal leather pieces are respectively located at two sides of
the straight line; every integrally formed three-leather-unit
comprises two regularly hexagonal leather pieces and one regularly
pentagonal leather piece, the two regularly hexagonal leather
pieces and the regularly pentagonal leather piece are arranged in a
straight line, the two regularly hexagonal leather pieces are
connected with each other, the regularly pentagonal leather piece
is connected with one of the two regularly hexagonal leather
pieces. In spite that the Chinese patent reduces the amount and the
difficulty of the attaching or sewing, and increases the accuracy
thereof, during the cutting the leather pieces, the
four-leather-units and the three-leather-units are large in length,
so that the raw materials are wasted. Therefore, once this football
is produced on a large scale, the raw materials are greatly and the
input cost of the raw materials is increased.
SUMMARY OF THE PRESENT INVENTION
[0011] An object of the present invention is to overcome
shortcomings of the prior art for providing a sewn ball which has
excellent jumping ability, high strength, good durability, small
circumferential error, and excellent balance and flight
stability.
[0012] Accordingly, in order to accomplish the above object, the
present invention provides a sewn ball, which comprises an inner
tube and a housing, wherein the inner tube comprises a tube body, a
yarn layer and a rubber layer; the yarn layer is attached to an
external surface of the tube body, the rubber layer is attached to
an external surface of the yarn layer and is then vulcanized, in
such a manner that a rubber raw material of the rubber layer
permeates through yarn gaps of the yarn layer, so as to integrate
the tube body, the yarn layer with the rubber layer; the housing
wraps around and is attached to the inner tube.
[0013] Preferably, the sewn ball is a sewn football or a sewn
volleyball.
[0014] Preferably, a balance plate is provided on the inner tube
and located at a position where is coaxially aligned with a gas
nozzle and symmetrical to a spherical center.
[0015] Preferably, a thickness of the yarn layer is 0.1-1 mm.
[0016] Preferably, a circumferential error of the sewn ball is less
than 2 mm.
[0017] Preferably, the housing comprises 6-32 leather pieces.
[0018] Preferably, the tube body is a double layer tube body
comprising an internal layer body and an external layer body
tightly attached to the internal layer body.
[0019] Preferably, the rubber layer is an ordinary rubber layer or
a foamed rubber layer; after vulcanization, an external surface of
the rubber layer forms a layer of dense rubber membrane.
[0020] Preferably, the rubber layer comprises an internal layer
rubber, a yarn reinforcement layer and an external layer rubber,
wherein the internal layer rubber is attached to an interior of the
yarn layer, the yarn reinforcement layer is attached to an external
surface of the internal layer rubber, the external layer rubber is
attached to an external surface of the yarn reinforcement
layer.
[0021] According to the sewn ball, the present invention also
provides a manufacturing method of the sewn ball, which comprises
steps of:
[0022] (1) cutting a leather into a plurality of leather pieces
with a leather cutter, and then sewing the leather pieces according
to a spherical surface leather piece arrangement order to form a
housing, and meanwhile, leaving 1-4 edges of the housing as an
opening;
[0023] (2) preparing an inner tube, comprising:
[0024] (2A) preparing a tube body fittingly with a roundness of a
ball;
[0025] (2B) preparing a yarn ball comprising injecting gas into the
tube body, and measuring a periphery thereof, winding yarns around
an external surface of the tube body with a yarn winding
machine;
[0026] (2C) preparing a rubber raw material ball by attaching a
rubber raw material to an external surface of the yarn ball;
and
[0027] (2D) preparing a vulcanizing inner tube comprising steps of:
putting the rubber raw material ball prepared by the step (2C) into
a vulcanizing mould, communicating a gas injection needle on the
vulcanizing mould with a gas nozzle of the rubber raw material ball
and pressurizing, heating and vulcanizing with a vulcanizing
temperature of 95-160.degree. C., a pressure of 3-10 kg/cm.sup.2
and a vulcanizing time of 4-10 min, permeating the rubber raw
material through yarn gaps after vulcanization, and vulcanizing
mould unloading for obtaining the inner tube;
[0028] (3) coating or not coating a binder on a surface of the
inner tube obtained by the step (2);
[0029] (4) coating a glue around an air hole of the housing
obtained by the step (1) and the gas nozzle of the inner tube
obtained by the step (2);
[0030] (5) putting the inner tube into the housing from the opening
thereof, cementing after corresponding the gas nozzle of the inner
tube to the air hole of the housing, and sewing the opening of the
housing to prepare a pretreated sewn ball; and
[0031] (6) injecting gas into the pretreated sewn ball obtained by
the step (5) to form a round ball, putting the round ball into a
reshaping mould, pressurizing and reshaping with a pressure of 3-10
kg/cm.sup.2, a time of 1-8 min, and a mould temperature of
30-70.degree. C. for attaching the housing to the surface of the
inner tube, and cleaning a surface of the housing, thereby
obtaining the sewn ball, wherein a circumferential error of the
sewn ball is less than 2 mm.
[0032] Preferably, after the rubber raw material ball is prepared
in the step (2C), a balance plate is attached to a position where
is coaxially aligned with the gas nozzle and symmetrical to a
spherical center on the rubber raw material ball, and then the step
(2D) is processed.
[0033] Beneficial effects of the present invention are as
follows:
[0034] (1) In the present invention, the yarn layer is wound around
the external surface of the tube body, and the rubber layer is
attached to the external surface of the yarn layer. After
vulcanization, the rubber raw material of the rubber layer
permeates through the yarn gaps of the yarn layer, in such a manner
that the tube body, the yarn layer and the rubber layer form a
whole, which has compact structure, excellent gas tightness, high
strength and good durability. The thickness of the yarn layer
provided by the present invention is preferably 0.1-1 mm. Under the
premise of guaranteeing the enough restraint of the yarn layer to
the tube body injected with gas, the thickness of the yarn layer is
properly selected for improving the strength of the inner tube, and
simultaneously giving consideration to both the hardness of the
ball after being injected with gas and the jumping ability of the
ball. Furthermore, after vulcanization with the vulcanizing mould,
the rubber raw material of the rubber layer attached to the
external surface of the yarn layer permeates through the yarn gaps
of the yarn layer, to form the inner tube which sandwiches the yarn
between the external rubber and the internal rubber, so that the
surface softness of the ball injected with the gas is ensured, and
meanwhile, the circumferential error of the ball is greatly
reduced, thereby greatly improving the rebound ability of the
ball.
[0035] (2) The balance plate is located at a position where is
symmetrical to the gas nozzle on the inner tube for allowing the
center of gravity of the manufactured ball to lie in the spherical
center, so that the ball has excellent balance and the flight
stability of the ball is ensured. Therefore, when a player hits the
ball, an actual flight trajectory of the ball deviates from an
ideal trajectory thereof in small, so that a hit rate of the ball
is increased.
[0036] (3) After vulcanizing the inner tube with the vulcanizing
mould and pressurizing the inner tube with the reshaping mould, the
circumferential error of the inner tube and the circumferential
error of the sewn ball are able to be respectively accurately
ensured, so that the obtained sewn ball has small circumferential
error, excellent jumping ability and balance, and stable
flight.
[0037] (4) Furthermore, the tube body provided by the present
invention is a double layer tube body comprising an internal layer
body and an external layer body tightly attached to the internal
layer body, wherein the internal layer body is an ordinary single
tube, the external layer body is able to limit the internal layer
body to evenly expand to a needed shape and size, a
hardness-softness and a degree of jumping of the internal layer
body, so that a leakage phenomenon is effectively avoided to
improve a service life of the ball.
[0038] (5) In spite that the existing yarn tire is able to avoid a
burst during tire inflation and plays a role in forming, due to the
ball is mechanically wound with yarns, the yarns are always
unevenly wound, so that the ball is unable to be completely
controlled to achieve a determined shape. To solve the above
technical problem, the rubber layer of the present invention
further adopts sandwiching the yarn reinforcement layer between the
internal layer rubber and the external layer rubber. By a double
forming of the yarn layer and the yarn reinforcement layer, the
ball is completely controlled to achieve the determined shape, so
that when the ball is squeezed in a long term and strongly
impacted, the yarn reinforcement layer enhances a strength of an
impact resistance of the ball, thus ensuring a resilience strength
and an excellent jumping ability and prolonging the service life of
the ball.
[0039] These and other objectives, features, and advantages of the
present invention will become apparent from the following detailed
description, the accompanying drawings, and the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 is a partially structurally schematic view of a sewn
ball provided by the present invention.
[0041] FIG. 2 is a partially structurally schematic view of the
sewn ball according to the Embodiment 3 of the present
invention.
[0042] FIG. 3 is a partially structurally schematic view of a
double layer tube body according to the Embodiment 5 of the present
invention.
[0043] FIG. 4 is a partially structurally schematic view of a
rubber layer according to the Embodiment 6 of the present
invention.
[0044] FIG. 5 is a schematic view of a housing of the present
invention.
[0045] In the drawing, 1: tube body; 2: yarn layer; 3: rubber
layer; 4: housing; 5: inner tube; 6: gas nozzle; 7: balance plate;
8: air hole; 1-1: internal layer body; 1-2: external layer body;
3-1: internal layer rubber; 3-2: yarn reinforcement layer; 3-3:
external layer rubber; 4-1: dual-leather-unit; 4-2:
four-leather-unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0046] The present invention is further described in detail
accompanying with the drawing.
Embodiment 1
[0047] Referring to the drawing, a sewn ball is illustrated,
comprising an inner tube 5 and a housing 4, wherein the inner tube
5 comprises a tube body 1, a yarn layer 2 and a rubber layer 3,
wherein the yarn layer 2 is attached to an external surface of the
tube body 1; the rubber layer 3 is attached to an external surface
of the yarn layer 2 and is then vulcanized, in such a manner that a
rubber raw material of the rubber layer 3 permeates through the
yarn layer 2, so as to integrate the tube body 1, the yarn layer 2
with the rubber layer 3; and the housing wraps around and is
attached to the inner tube 5.
Embodiment 2
[0048] If the thicker yarn layer 2 winds around the tube body 1, a
surface of the manufactured inner tube 5 is harder, so that a
jumping ability of a ball is affected; and meanwhile, if the
thinner yarn layer 2 winds around the tube body 1, the yarn layer 2
is unable to sufficiently bind up the tube body 1, so that the
inner tube 5 has low strength, poor damage resistance and is not
durable. To avoid the above situations, preferably, a thickness of
the yarn layer 2 is 0.1-1 mm. Under a premise of guaranteeing an
enough restraint of the yarn layer 2 to the tube body 1, the
thickness of the yarn layer 2 is properly selected for improving
the strength of the inner tube 5, and simultaneously giving
consideration to both the surface hardness and the jumping ability
of the ball.
Embodiment 3
[0049] As shown in FIG. 2, if a balance and a flight stability of
the ball are ensured, when a player hits the ball, an actual flight
trajectory of the ball deviates from an ideal trajectory thereof in
small, so that a hit rate of the ball is increased. Accordingly, a
balance plate 7 is located on the inner tube 5 provided by the
present invention, and is coaxially aligned with a gas nozzle 6 and
symmetrical to a spherical center, such that a whole center of
gravity of the ball lies in the spherical center.
Embodiment 4
[0050] The rubber layer 3 of the present invention is an ordinary
rubber layer or a foamed rubber layer. After vulcanization, an
external surface of the rubber layer 3 forms a layer of dense
rubber membrane. While the foamed rubber layer is adopted, after
vulcanization, the surface of the inner tube 5 forms numerous
foaming holes, so that the ball is soft, and meanwhile, the
external surface of the rubber layer 3 forms the layer of dense
rubber membrane, thus a gas tightness of the ball is improved and a
leakage of gas inside the ball is avoided. Therefore, the ball has
excellent gas tightness and compact structure.
Embodiment 5
[0051] As shown in FIG. 3, preferably, the tube body 1 is a double
layer tube body comprising an internal layer body 1-1 and an
external layer body 1-2 tightly attached to the internal layer
body, wherein the internal layer body 1-1 is an ordinary single
tube, the external layer body 1-2 is able to limit the internal
layer body 1-1 to evenly expand to a needed shape and size, and a
hardness-softness of the internal layer body, so that a leakage
phenomenon is effectively avoided to improve a service life of the
ball.
Embodiment 6
[0052] As shown in FIG. 4, preferably, the rubber layer 3 comprises
an internal layer rubber 3-1, a yarn reinforcement layer 3-2 and an
external layer rubber 3-3, wherein the internal layer rubber 3-1 is
attached to an interior of the yarn layer 2, the yarn reinforcement
layer 3-2 is attached to an external surface of the internal layer
rubber 3-1, the external layer rubber 3-3 is attached to an
external surface of the yarn reinforcement layer 3-2. In spite that
the existing yarn tire is able to avoid a burst during tire
inflation and plays a role in forming, due to the ball is
mechanically wound with yarns, the yarns are always unevenly wound,
so that the ball is unable to be completely controlled to achieve a
determined shape. To solve the technical problem, the rubber layer
3 of the present invention further adopts sandwiching the yarn
reinforcement layer 3-2 between the internal layer rubber 3-1 and
the external layer rubber 3-3. By a double forming of the yarn
layer 2 and the yarn reinforcement layer 3-2, the ball is
completely controlled to achieve the determined shape, so that when
the ball is squeezed in a long term and strongly impacted, the yarn
reinforcement layer 3-2 enhances a strength of an impact resistance
of the ball, thus ensuring a resilience strength and an excellent
jumping ability and prolonging the service life of the ball.
[0053] In the above embodiments, the sewn ball of the present
invention is a sewn football or a sewn volleyball.
[0054] The housing of the present invention comprises 6-32 leather
pieces. These leather pieces are sewn and connected with each other
to form the housing of the sewn ball, 1-4 edges which are not sewn
are left to act as an opening for installing the inner tube.
[0055] Referring to FIG. 5, preferably, when the sewn ball is the
sewn football, the housing 4 comprises eight integrally formed
dual-leather-units 4-1 and eight integrally formed
four-leather-units 4-2, wherein every dual-leather-unit 4-1
comprises two regular hexagon leather pieces connected with each
other; every four-leather-unit 4-2 comprises three regular pentagon
leather pieces and a regular hexagon leather piece, the three
regular pentagon leather pieces are not adjacent to each other and
are connected with the regular hexagon leather piece. The structure
of the housing 4 reduces an amount of the leather pieces thereof,
decreases a sewing amount of the leather pieces, reduces a sewing
difficulty, and meanwhile, saves raw materials, improves an
integral roundness of the spherical surface of the sewn football.
Compared with ten leather pieces, the present invention is able to
better use residual materials, and save costs of raw materials,
thereby better meeting needs for sewing footballs in mass
production.
[0056] According to the structural description of the above
embodiments, a manufacturing method of the sewn ball provided by
the present invention is provided, which comprises steps of:
[0057] (1) cutting a leather into a plurality of leather pieces
with a leather cutter, and then sewing the leather pieces according
to a spherical surface leather piece arrangement order to form a
housing 4, and meanwhile, leaving 1-4 edges of the housing 4 as an
opening;
[0058] (2) preparing an inner tube 5, comprising:
[0059] (2A) preparing a tube body 1 fittingly with a roundness of a
ball;
[0060] (2B) preparing a yarn ball comprising injecting gas into the
tube body 1, and measuring a periphery thereof, winding yarns
around an external surface of the tube body 1 with a yarn winding
machine;
[0061] (2C) preparing a rubber raw material ball by attaching a
rubber raw material to an external surface of the yarn ball;
and
[0062] (2D) preparing a vulcanizing inner tube 5 comprising steps
of: putting the rubber raw material ball prepared by the step (2C)
into a vulcanizing mould, communicating a gas injection needle on
the vulcanizing mould with a gas nozzle 6 of the rubber raw
material ball and pressurizing, heating and vulcanizing with a
vulcanizing temperature of 95-160.degree. C., a pressure of 3-10
kg/cm.sup.2 and a vulcanizing time of 4-10 min, permeating the
rubber raw material through yarn gaps after vulcanization, and
vulcanizing mould unloading for obtaining the inner tube 5;
[0063] (3) coating or not coating a binder on a surface of the
inner tube 5 obtained by the step (2), wherein the binder is
preferably emulsion or waterborne glue;
[0064] (4) coating a glue around an air hole 8 of the housing
obtained by the step (1) and the gas nozzle 6 of the inner tube 5
obtained by the step (2);
[0065] (5) putting the inner tube 5 into the housing 4 from the
opening thereof, cementing after corresponding the gas nozzle 6 of
the inner tube 5 to the air hole 8 of the housing 4, and sewing the
opening of the housing 4 to prepare a pretreated sewn ball; and
[0066] (6) injecting gas into the pretreated sewn ball obtained by
the step (5) to form a round ball, putting the round ball into a
reshaping mould, pressurizing and reshaping with a pressure of 3-10
kg/cm.sup.2, a time of 1-8 min, and a mould temperature of
30-70.degree. C. for attaching the housing 4 to the surface of the
inner tube 5, and cleaning a surface of the housing 4, thereby
obtaining the sewn ball, wherein a circumferential error of the
sewn ball is less than 2 mm.
[0067] Preferably, referring to FIG. 2, after the rubber raw
material ball is prepared in the step (2C), a balance plate 7 is
attached to a position where is coaxially aligned with the gas
nozzle 6 and symmetrical to a spherical center on the rubber raw
material ball, and then the step (2D) is processed. The balance
plate 7 is a rubber plate with a weight equivalent to the gas
nozzle. The balance plate 7 ensures that the center of gravity of
the whole ball lies in the spherical center so as to avoid the ball
to derivate from the spherical center for affecting the flight
stability of the ball.
[0068] During the manufacturing process of the inner tube 5, while
vulcanizing with the vulcanizing mould, the rubber raw material of
the rubber layer 3 permeates through the yarn gaps of the yarn
layer 2, in such a manner that the tube body 1, the yarn layer 2
and the rubber layer 3 form a whole to form the inner tube 5
sandwiching the yarns between an inner rubber and an outer rubber,
which has compact structure and excellent gas tightness, not only
ensures a surface softness after injecting the gas into the inner
tube 5, but also increases a rebound ability, and simultaneously,
the vulcanizing mould ensures that the circumferential error of the
vulcanizing inner tube 5 prepared by vulcanizing mould unloading is
in an error range, thereby greatly improving the jumping ability,
balance and flight stability of the ball, avoiding the
circumferential error of the inner tube 5 to accumulate to the
housing, which leads to a larger accumulated circumferential error
of the ball, and affects the jumping ability, the balance and the
flight stability of the ball.
[0069] After putting the inner tube 5 into the housing 4, the
opening is sewn, the sewn ball is then put into the reshaping
mould, pressurized and reshaped, so as to ensure that the
circumferential error of the obtained sewn ball is less than 2 mm.
The present invention overcomes the shortcomings of the prior art,
and puts the inner tube 5 into the housing 4 after coating the
binder on the surface of the inner tube 5 or directly puts the
inner tube 5 into the housing 4 without coating the binder on the
surface of the inner tube 5, which leads to the uncontrollable
circumferential error of the surface of the housing 4. In general,
the circumferential error of the conventional sewn ball reaches 3-5
mm. Accordingly, the ball has poor jumping ability, poor balance
and unstable flight. Furthermore, the inner tube 5 obtained by the
prior art is vulcanized with the vulcanizing mould, so that the
circumferential error of the obtained inner tube 5 is similarly
unable to be controlled, thereby leading to large circumferential
error of the inner tube 5 and directly affecting the
circumferential error of the sewn ball.
[0070] The circumferential error of the sewn ball provided by the
present invention is less than 2 mm, that of the inner tube 5 is
controlled with the vulcanizing mould, and that of the sewn ball is
controlled with the reshaping mould. The circumferential error of
the inner tube 5 and the sewn ball gives consideration to both the
jumping ability of the ball and the manufacturing cost of
production, which includes a control cost of a circumferential
accuracy of an internal surface of the vulcanizing mould and the
reshaping mould.
[0071] According to the Embodiment 4, to improve the gas tightness
of the inner tube 5, after the rubber raw material ball is prepared
in the step (2C), the surface of the inner tube 5 prepared by
vulcanizing mould unloading forms the layer of dense rubber
membrane, so that the inner tube 5 has excellent gas tightness and
durability.
[0072] The above descriptions show the basic principle, main
characteristics and advantages. One skilled in the art will
understand that the embodiment of the present invention as shown in
the drawings and described above is exemplary only and not intended
to be limiting. It will thus be seen that the objects of the
present invention have been fully and effectively accomplished. Its
embodiments have been shown and described for the purposes of
illustrating the functional and structural principles of the
present invention and is subject to change without departure from
such principles. Therefore, this invention includes all
modifications encompassed within the spirit and scope of the
following claims.
* * * * *