WO2000041870A1

WO2000041870A1 - A hose and its fabricating apparatus

Info

Publication number: WO2000041870A1
Application number: PCT/KR1999/000015
Authority: WO
Inventors: Kyo Il Lee
Original assignee: Kyo Il Lee
Priority date: 1999-01-09
Filing date: 1999-01-09
Publication date: 2000-07-20
Also published as: AU2077199A

Abstract

The present invention is directed to provide a hose and its fabricating apparatus in which a tubular woven fabric (100) obtained by winding circumferential woof threads in the same direction as a line of action of circumferential tensile force is coated with a synthetic resin on the inner and outer surfaces, thereby increasing permissible internal pressure of the hose and simplifying the fabrication process. In particular, the present invention includes a synthetic resin coating unit (30) which has a synthetic resin feeding die (36) with synthetic resin feeding ports (37 and 38), and a mandril (31) with a synthetic resin passage (32), and is adapted to coat inner and outer skins (101 and 102) of the hose in a single step.

Description

TITLE

A HOSE AND ITS FABRICATING APPARATUS

TECHNICAL FIELD The present invention generally relates to a hose and its fabricating apparatus. More particularly, it relates to a hose and its fabricating apparatus in which circumferential woof threads of a tubular woven fabric are wound in the same direction as a line of action of the circumferential tensile force so as to enhance permissible internal pressure of the hose, the inner and outer skins of the hose are coated with materials different from each other without forming a boundary layer between them, thereby prolonging the life of the hose, and the hose fabrication process is simplified to enhance the productivity.

BACKGROUND ART

A hose is usually a tube-shaped material elastic and flexible and it has a reinforcing fabric layer which is adapted to allow the hose to endure the pressure caused by a fluid in the hose. Examples of such a hose include fire hose, synthetic resinous hose, rubber hose and the like.

Out of various hoses, in an aspect of use purpose, a fire hose must be light-weighted and exhibit high permissible internal pressure with the outer skin having high durability. For those requirements, the fire hose is fabricated in the following procedure:

First, a tubular woven fabric is woven in the unit of 30 to 50 meters in length to be used as a reinforcing fabric layer as well as an outer skin in order to increase the permissible internal pressure and enhance durability of the outer skin, and an inner skin is formed in the unit of 30 to 50 meters in length and 0.5 mm thick in order to reduce the weight of the fire hose. Second, an adhesive is applied to the outer circumferential surface of the inner skin formed in the unit of 30 to 50 meters, which is then inserted manualy into the tubular woven fabric.

Third, vapor heated to about 100°C is injected into the inner skin inserted into the tubular woven fabric to melt the adhesive applied to the outer circumferential surface of the inner skin in such a manner that the adhesive combines the inner skin and the tubular woven fabric. The vapor pressure the enables the inner skin to be closely combined with tubular woven fabric to complete a fire hose finally.

As for the fire hose fabricated in the prescribed process as illustrated in Figs. 1 and 2, however, the woof threads around the circumference of the tubular woven fabric is not wound in the same direction as a line of action of the circumferential tensile force but in the angled direction with respect to the line of action such that the hose cannot stand the tensile force efficiently and will be distorted in the winding direction of the wood threads under the pressure of about 15 to 20 kg/cm₂ with an inconvenience in use. Furthermore, insertion of the inner skin into the tubular woven fabric is performed manually, which raises some problems such as reduction in the productivity and changes of the inner diameter of the inner skin so that the standardization of the hose is hardly achieved. A synthetic resinous hose is widely spread for home uses and made of low-priced chloride vinyl excellent in elasticity and flexibility as a principal material in the following fabrication process.

First, an inner skin is extruded in the 2.0 to 5.0 mm range of thickness based on the inner diameter of the hose and an adhesive is applied to the outer circumferential surface of the inner skin.

Second, a plurality of pieces of reinforcing threads are spirally wound around the circumferential surface of the inner skin coated with the adhesive, part of which are wound in the right direction and the rest are wound in the left direction to form a net-like reinforcing fabric layer.

Third, an outer skin is extruded on the outer circumferential surface of the reinforcing fabric layer wound around the inner skin, thereby completing the synthetic resinous hose.

As for the synthetic resinous hose fabricated in the prescribed process as shown in Figs. 3 and 4, however, more than two pieces of synthetic resinous layers are hardly formed due to the characteristic of a synthetic resin molding apparatus and the reinforcing threads constituting the reinforcing fabric layer are spirally wound in an angled direction with respect to the line of action instead of being wound in the same direction as a line of action of the circumferential tensile force. Such a synthetic resinous hose cannot stand the tensile force efficiently with low permissible internal pressure (i.g., 6.0 kg/cm based on D:20 mm) and will be used only for home uses. Furthermore, the inner skin has to be thickened in order to prevent distortion during formation of the reinforcing fabric layer with a consequence of problems in that the material is wasteful used and the weight & the cost of the hose increases.

A rubber hose is primarily used for industrial uses and has a plurality of reinforcing fabric layers according to the purpose to be used at the permissible internal pressure between 10 and 20 kg/cm². The rubber hose is fabricated in the following procedure.

First, a paste of rubber materials is prepared based on the use purpose to be extruded an inner skin. Second,. a plurality of pieces of reinforcing threads are spirally wound around the circumferential surface of the inner skin, part of which are wound in the right direction and the rest are wound in the left direction to form a net-like reinforcing fabric layer. Third, a paste of rubber materials is prepared is applied to the outer circumferential surface of the reinforcing fabric layer wound around the inner skin to form a rubber layer.

Fourth, the proceeding procedures are repeated about two or three times according to the use purpose of the hose. Fifth, as the formed rubber hose has no elasticity peculiar to a rubber material, it is steamed at 150°C in a steam tank to be stabilized and an elastic rubber hose is finally completely.

Like the synthetic resinous hose, however, the rubber hose fabricated in the prescribed process as shown in Figs. 5 and 6 has the reinforcing threads constituting the reinforcing fabric layer and spirally wound in an angled direction with respect to the line of action instead of being wound in the same direction as a line of action of the circumferential tensile force. Such a rubber hose cannot stand the tensile force efficiently with low permissible internal pressure. Furthermore, the inner skin has to be thickened in order to prevent distortion during formation of the reinforcing fabric layer, consuming much more materials unnecessarily, and a plurality of pieces of reinforcing fabric layers and .rubber layers are used in order to enhance permissible internal pressure, thereby increasing the weight of the hose. An additional process for stabilizing a rubber material is also problematic because it limits the length of the hose fabricated to the range between 20 to 30 meters.

In the conventional hose fabricating method, a conventional fire hose, the synthetic resinous hose and the rubber hose are all provided with the reinforcing fabric layer which is constituted by reinforcing threads wound in an angled direction with respect to a line of action of the circumferential tensile force such that they cannot stand the tensile force efficiently and, furthermore, the fabrication process is too complicated and the hose becomes heavy.

DISCLOSURE OF THE INVENTION

Accordingly, the present invention is directed to provide a hose and its fabricating apparatus in which a tubular woven fabric 100 obtained by winding circumferential woof threads in the same direction as a line of action of circumferential tensile force is coated with a synthetic resin on the inner and outer surfaces, thereby increasing permissible internal pressure of the hose and simplifying the fabrication process.

In particular, the present invention includes a synthetic resin coating unit 30 which has a synthetic resin feeding die 36 with synthetic resin feeding ports 37 and 38, and a mandril 31 with a synthetic resin passage 32, and is adapted to coat inner and outer skins 101 and 102 of the hose in a single step.

It is therefore possible to increase the permissible internal pressure of the hose and coat the inner and outer skins 101 and 102 with synthetic resins different from each other, as a consequence of which the fabrication process is simplified with enhanced productivity and quality of products.

Accordingly, an object of the present invention is to provide a hose and its fabricating method in which circumferential woof threads of a tubular woven fabric are wound in the same direction as a line of action of the circumferential tensile force so as to enhance permissible internal pressure of the hose, the inner and outer skins of the hose are integrally formed without a boundary layer and enabled to be coated with materials different from each other, thereby enhancing the product quality as well as prolonging the life of the hose, and the hose fabrication process is simplified to enhance the productivity. In an aspect of the present invention, a tubular woven fabric prepared with circumferential woof threads wound in the same direction as a line of action of circumferential tensile force is coated with a stabilized, hot synthetic resin on its inner and outer surfaces to fabricate a hose. Especially, the inner and outer surfaces of the tubular woven fabric can be coated with synthetic resins different from each other.

Thus, the permissible internal pressure of the hose is increased and the fabrication process can be simplified because the inner and outer skins of the hose are formed in a single step, enhancing the productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a partial cross-sectional view of a fire hose; Fig. 2 is a partial enlarged view of a reinforcing fabric layer of the fire hose;

Fig. 3 is a partial cross-sectional view of a synthetic resinous hose;

Fig. 4 is a partial enlarged view of a reinforcing fabric layer of the synthetic resinous hose; Fig. 5 is a partial cross-sectional view of a rubber hose;

Fig. 6 is a partial enlarged view of a reinforcing fabric layer of the rubber hose;

Fig. 7 is an exemplary view illustrating the whole construction, of the present invention;

Fig. 8 is an exemplary cross-sectional view of a synthetic resin coating unit in an apparatus for fabricating a hose according to the present invention;

Fig. 9 is an exemplary perspective of a mandril in the apparatus of the present invention; Fig. 10 is a cross-sectional view taken along the line A-A of Fig. 9;

Fig. 11 is a partial cross-sectional view of a hose fabricated in accordance with the present invention; and Fig. 12 is a detailed view of a tubular woven fabric in the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereafter, the present invention will be described in detail with reference to the accompanying drawings.

Fig. 7 is an exemplary view illustrating the whole construction of the present invention, and Fig. 8 is an exemplary cross-sectional view of a synthetic resin coating unit in an apparatus for fabricating a hose according to the present invention. Fig. 9 is an exemplary perspective of a mandril in the apparatus of the present invention and Fig. 10 is a cross-sectional view taken along the line A-A of Fig. 9. Fig. 11 is a partial cross-sectional view of a hose fabricated in accordance with the present invention, and Fig. 12 is a detailed view of a tubular woven fabric of the present invention. The present invention is directed to a hose which can be produced in a simplified fabrication process by coating inner and outer skins 101 and 102 with materials different from each other with enhancing the permissible internal pressure. Especially, the hose is fabricated with a liquid synthetic resin applied to the internal and external surfaces of a tubular woven fabric 100.

As shown in Fig. 7, the present invention includes: a cylindrical spread feeding unit 10 for spreading the tubular woven fabric 100 constituted by circumferential woof threads 100a wound in the same direction of a line of action of the circumferential tensile force and moving it downward; a preheating unit 20 for pre-heating the tubular woven fabric 100 spread in the cylindrical form at the cylindrical spread feeding unit 10; a synthetic resin coating unit 30 for coating the tubular woven fabric 100 pre-heated at the pre-heating unit 20 with a synthetic resin to form a hose; and a cooling unit 40 for cooling the hose formed by coating the tubular woven fabric 100 with the synthetic resin at the synthetic resin coating unit 30.

The tubular woven fabric 100, as illustrated in Fig. 12, is formed from the circumferential woof threads 100a and the lengthwise-directional warp threads 100b which are woven to make a right angle with each other and form a rectangular- shaped fabric. The circumferential woof threads 100a are wound in the same direction as a line of action of the circumferential tensile force occurring due to the internal pressure and woven so as not to get distorted or bulky under the internal pressure. The pre-heating unit 20 is cylindrically shaped and pre- heats the tubular woven fabric 100 at about 200 °C lest the hot liquid synthetic resin be cooled due to the tubular woven fabric 100 and lose liquidity at the following synthetic resin coating unit 30. The pre-heating process also prevents a deterioration in the adhesion due to temperature difference. On the other hand, the synthetic resin coating unit 30, as shown in Figs. 7 and 8, includes synthetic resin extruders E, a synthetic resin feeding die 36 and a mandril 31. The synthetic resin extruders E are associated with the synthetic resin feeding die 36 such that they transfers at high pressure a liquid synthetic resin made of a mixture of synthetic resinous materials and stabilized at a raised temperature of about 200°C to the synthetic resin feeding die 36.

The synthetic resin feeding die 36 is provided with synthetic resin feeding ports 37 and 38 which are formed in the annular form on the inner wall of the synthetic resin feeding die 36 to coat the tubular woven fabric 100 with the liquid synthetic resin transferred from the synthetic resin extruders E. Each of the synthetic resin feeding ports 37 and 38 includes: an internal feeding port 37 for coating the inner surface of the tubular woven fabric 100 with the synthetic resin supplied from the respective synthetic resin extruders E, and an external feeding port 37 for coating the outer surface of the tubular woven fabric 100 with the synthetic resin. As shown in Figs. 9 and 10, the mandril 31 is received in the synthetic resin feeding die 36 in order to facilitate transfer of the tubular woven fabric 100. The mandril 31 includes: a synthetic resin passage 32 having a path for the liquid synthetic resin flowing along the inner surface of the tubular woven fabric 100 at a portion with the synthetic resin feeding ports 37 and 38 formed therein, especially, a portion with the internal feeding port 37 formed therein; and a ring- shaped support 33 adapted to maintain the shape of the tubular woven fabric 100 against the pressure of the liquid synthetic resin supplied to the synthetic resin passage 32 via the synthetic resin feeding ports 37 and 38.

Furthermore, a hose outlet 34 is formed in the lower part of the synthetic resin coating unit 30 to let out the hose that includes the tubular woven fabric 100 is coated with the synthetic resin on the inner and outer surfaces. The thickness of the synthetic resin coating applied to the outer surface of the tubular woven fabric 100 is determined by the inner diameter of the synthetic resin feeding die 36, while the thickness of the synthetic resin coating applied to the inner surface of the tubular woven fabric 100 is dependant upon the outer diameter of the mandril 31.

Next, a process for fabricating a hose is described in accordance with the present invention. The tubular woven fabric 100 is spread in the disc form at the cylindrical spread feeding unit 10 in order to be later pre-heated uniformly at the pre-heating unit 20 and easily coated with the synthetic resin at the synthetic resin coating unit 30. The tubular woven fabric 100 spread at the cylindrical spread feeding unit 10 is then transferred to the pre-heating unit 20 to be pre-heated at about 200°C for preventing a reduction of the liquidity of the synthetic resin at the synthetic resin coating unit 30 and enhancing the adhesive strength of the liquid synthetic resin. The tubular woven fabric 100 pre-heated at the preheating unit 20 is coated with the liquid synthetic resin on the inner and outer surfaces at the synthetic resin coating unit 30 to form a hose, which is finally moved to the cooling unit 40 to be cooled with a cooling water. The following detailed description is a process for coating the inner and outer surfaces of the tubular woven fabric 100 with the liquid synthetic resin at the synthetic resin coating unit 30.

Upon being transferred from the synthetic resin extruders E under pressure and discharged from the internal feeding port 37 of the synthetic resin coating unit 30, part of the liquid synthetic resin flows along the synthetic resin passage 32 formed in the mandril 31 through the tubular woven fabric 100 to be coated on the inner surface of the tubular woven fabric 100. The support 33 formed in the mandril 31 maintains the shape of the tubular woven fabric 100 against the pressure of the liquid synthetic resin discharged through the internal feeding port 37 and supports the tubular woven fabric 100 so as for the liquid synthetic resin to enter the synthetic resin passage 32.

Part of the liquid synthetic resin transferred from the synthetic resin extruders E under pressure and discharged from the external feeding port 38 of the synthetic resin coating unit 30 is applied onto the outer circumferential surface of the tubular woven fabric 100 whose inner surface has been coated with the liquid synthetic resin supplied from the internal feeding port 37. The liquid synthetic resin supplied from the external feeding port 38 cannot pass through the tubular woven fabric 100 because of the liquid synthetic resin filling the inside of the tubular woven fabric 100 and mixed with the liquid synthetic resin coated on the inner surface of the tubular woven fabric 100.

The tubular woven fabric 100 whose inner and outer surfaces are coated with the liquid synthetic resin is then discharged as a hose via the hose outlet 34. In the meanwhile, the inner diameter of the hose is determined by the outer diameter of the mandril 31 and the outer diameter of the hose is determined by the inner diameter of the synthetic resin feeding die 36. On the other hand, the types of the synthetic resins respectively supplied from the internal and external feeding ports 37 and 38 of the synthetic resin feeding die 36 are dependent upon the use purposes of the hose. For example, the inner skin 101 is coated with a special synthetic resin having resistance to chemicals, while the outer skin 102 is coated with another special synthetic resin excellent in durability.

INDUSTRIAL APPLICABILITY

Such as in the present invention described above, the reinforcing threads are wound in the circumferential direction as same as a line of action of circumferential tensile force to increase permissible internal pressure, and the inner and outer skins can be coated with synthetic resins different from each other, making it possible to fabricate products of good quality. A hot stabilized synthetic resin is directly applied to the tubular woven fabric in the fabrication without performing a separate process for stabilizing the synthetic resin and the flow of the processing goes on to a cooling step. The inner and outer skins of the tubular woven fabric are formed in a single step without additional processing, thereby reducing the time for production and enhancing the productivity.

Furthermore, the present invention is very practical in that the inner and outer skins are formed in a single step and integrated with each other without forming a boundary between them to prevent a reduction of life due to moisture permission .

Claims

WHAT IS CLAIMED IS:

1. An apparatus for fabricating a hose, comprising: a cylindrical spread feeding unit for spreading a tubular woven fabric in a disc form to be transferred to another unit; a pre-heating unit for pre-heating the tubular woven fabric spread at the cylindrical spread feeding unit in order to enhance adhesive strength of a liquid synthetic resin without deteriorating the liquidity of the synthetic resin in the next processing step; a synthetic resin coating unit for coating the pre-heated tubular woven fabric with the synthetic resin; and a cooling unit for cooling the hose discharged from the synthetic resin coating unit, wherein the synthetic resin coating unit comprises: a synthetic resin extruder for transferring the heated and stabilized synthetic resin under pressure, a synthetic resin feeding die having synthetic resin feeding ports formed in the annular form on a inner wall thereof and adapted for inner and outer surfaces of the tubular woven fabric to be coated with the synthetic resin transferred from the synthetic resin extruder, and a mandril received in the synthetic resin feeding die, wherein the mandril comprises: a synthetic resin passage having a path for the liquid synthetic resin flowing along the inner surface of the tubular woven fabric at a portion with the synthetic resin feeding ports formed therein, and a ring-shaped support adapted to be associated with the synthetic resin passage to support the tubular woven fabric against the pressure of the liquid synthetic resin supplied through the synthetic resin feeding ports, wherein a hose outlet is formed in the lower part of the synthetic resin coating unit for determining the thickness of the synthetic resin coated on the tubular woven fabric by the inner diameter of the synthetic resin feeding die and the outer diameter of the mandril.

2. The apparatus as claimed as claim 1, wherein the synthetic resin feeding ports formed in the synthetic resin feeding die of the synthetic resin coating unit are supplied with a liquid synthetic resin through synthetic resin extruders in an independent manner of each other for the inner and outer surfaces of the tubular woven fabric to be coated with materials different from each other, the synthetic resin feeding ports comprising: an internal feeding port adapted to coat the inner surface of the tubular woven fabric; and an external feeding port formed under the internal feeding port and adapted to coat the outer surface of the tubular woven fabric.

3. A hose formed by weaving lengthwise warp threads and circumferential woof threads to make a right angle with each other, the circumferential woof threads being wound in the same direction as a line of action of circumferential tensile force, and then coating inner and outer surfaces of a tubular woven fabric with a synthetic resin.