Molded hose with fabric layer

A reinforced hose includes an inner layer, a reinforcing intermediate layer, and an outer layer. The inner layer has and inwardly projecting sealing rib extending circumferentially on an inner surface thereof. The inner surface may also have an end stop to be engaged by a fitting received in the hose. The outer layer has a pair of annular clamp guides projecting outwardly which are axially spaced from an end of the hose. The sealing rib is positioned between the clamp guides to indicate an optimum location for a hose clamp.

BACKGROUND OF THE INVENTION

The present invention relates to hoses and hose apparatus and to methods for manufacturing such hoses. More particularly, the present invention relates to types of hoses which are used with clamps for sealing connections to fittings.

A hose is a flexible tubular structure for conveying a fluid from one location to another. Some hoses are used in portable situations, such as garden hoses and fire hoses which carry water from sources to nozzles or other distribution devices, such as a sprinklers. Such hoses usually have conveniently removable connectors, such as threaded connectors. Other types of hoses are used in more fixed situations, such as where fittings to be connected by the hose are not aligned or where there is some movement between the interconnected fittings. Such hoses are often connected to the fittings by less conveniently removable means, such as circumferential clamps. Hoses intended for carrying fluids at high pressures are usually reinforced, as by one or more layers of a reinforcing fabric or other material. Hoses intended for use where they are subject to abrasive contact are provided with toughened external layers.

In a situation in which a hose is not under significant pressure or axial stresses, a hose may be retained on a fitting by frictional contact alone and adequately seal the carried fluid therein. If the hose is to be subjected to relatively high pressures and/or axial stresses, a retainer mechanism is usually employed to retain the hose on the fitting and to maintain a fluid seal between the hose and the fitting, such as a circumferential clamp. Conventional hoses do not provide structure to limit how far the hose should be sleeved onto a fitting or to suggest the most effective location to place a circumferential clamp.

In automotive applications, a coolant or water pump is employed to cycle an engine block coolant liquid through finned passages of a heat exchanger referred to as a “radiator” to transfer engine generated heat from the coolant to air flowing across the passages to thereby stabilize the temperature of the engine block. The radiator is typically rigidly mounted on a support frame, such as the vehicle chassis, while the engine, with block and water pump, is connected to the frame by somewhat resilient motor mounts to accommodate engine vibrations and engine movements in reaction to engine speed changes. Radiator hoses are typically used to connect the radiator to the engine block and water pump.

Friction between an inner surface of a hose and an outer surface of a fitting can cause difficulties when a the hose is sleeved onto the fitting. Thus, the diameters of the inner hose surface and outer fitting surface must be related in such a manner that excessive labor is not required to install the hose on the fitting and that leakage between the surfaces is not promoted.

Hoses may be formed of a variety of rubbers, polymers, and composites depending of their intended use and environment. Hoses may be formed in discrete lengths or continuously by molding processes, extrusion processes, or the like. Hoses may be formed to shape in a “raw” condition and subsequently processed or treated to cure or vulcanize the material for strengthening and incorporating desired characteristics. Reinforcing layers for hoses can be in the form of woven, braided, or wrapping of fibers or threads. Reinforcing layers can be applied in discrete lengths or continuously woven about a hose layer formed by a continuous process.

SUMMARY OF THE INVENTION

The present invention is directed to a hose structure including an elongated tubular hose member having an outer surface, an inner surface, and a tubular axis, the hose member having opposite ends and a radially outwardly projecting circumferential clamp guide formed on the outer surface of the hose member in axially spaced relation to an end of the hose member. An embodiment of the hose structure may have a pair of axially spaced clamp guides. The hose structure may have an inwardly projecting circumferential sealing rib formed on the inner surface of the hose guide member in axially spaced to the clamp guide or between a pair of clamp guides to improve sealing with a fitting when a circumferential clamp is positioned on the structure adjacent the clamp guide. The hose structure may also have an inwardly projecting stop structure on the inner surface in axially spaced relation to the clamp guide to limit penetration of a fitting into the hose structure.

An embodiment of a hose according to the present invention includes an elastomeric inner layer with an inner surface; an intermediate woven fabric layer; an elastomeric outer layer with an outer surface, and including a radially outward and circumferentially extending molded clamp guide on the outer layer. The inner layer may be formed by extrusion. The outer layer is then molded onto the inner layer along with the clamp guide. In another embodiment the hose may include a second clamp guide. In an embodiment the hose may further include the inwardly projecting, circumferentially sealing rib which is molded on the inner layer inner surface in spaced relation to the clamp guide or guides, such as between the pair of parallel clamp guides. In another embodiment, the hose further includes the inwardly projecting stop structure, the stop structure extending circumferentially about the inner surface and having a diameter that is smaller than both the rib diameter and the inner surface diameter so an end of a fitting on which the hose is sleeved abuts the stop structure when an optimum length of the hose is slid onto the fitting.

A method of forming a hose structure according to the present invention comprises the steps of: forming an elongated tubular hose member having an outer surface, an inner surface, a tubular axis, and a substantially constant inner diameter, the hose member having opposite ends; and molding an outer layer onto the outer surface of the hose member, the outer layer including an outwardly projecting circumferential clamp guide, or pair of clamp guides, positioned in axially spaced relation to an end of the hose member. An intermediate layer, such as a reinforcing layer, may be formed on the inner layer prior to molding the outer layer. The outer layer may be molded using a mold having a cylindrical inner surface with circumferential clamp guide grooves which forms the clamp guides. The hose structure can be supported internally during molding of the outer layer by an elongated mandrel having a substantially constant diameter. The mandrel can be provided with one or more circumferential grooves to form one or more inwardly projecting circumferential sealing ribs on the inner surface of the hose structure. The mandrel can be provided with an additional circumferential groove to form an inwardly projecting circumferential stop member on the inner surface of the hose member in axially spaced relation to the clamp guide.

The present invention includes a method of forming a hose structure comprising the steps of: forming an elongated tubular hose member having an outer surface, an inner surface, a tubular axis, and a substantially constant inner diameter, the hose member having opposite ends; and molding an outer layer onto the outer surface of the hose member, the outer layer including an outwardly projecting circumferential clamp guide positioned in axially spaced relation to an end of the hose member. The clamp guide can be formed using a mold having a cylindrical inner surface with circumferential clamp guide groove which forms the clamp guide or a pair of axially spaced which forms a pair of clamp guides.

An embodiment of the method may include the steps of providing an elongated mandrel having a substantially constant diameter; and inserting the mandrel into the hose member to support the hose member during molding of the outer layer. The mandrel may have a circumferential groove to support the hose member during molding of the outer layer and to form an inwardly projecting circumferential rib on the inner surface of the hose member in axially spaced relation to the clamp guide. The mandrel may also have another circumferential groove to form an inwardly projecting circumferential stop member on the inner surface of the hose member in axially spaced relation to the clamp guide. The method may include step of providing a reinforcing layer on said hose member prior to molding the outer layer thereon.

Alternative methods of forming hose structures of the present invention include the steps of forming a multilayer hose body having a substantially constant tubular inner diameter by forming an inner layer, forming an intermediate layer in surrounding relation to the inner layer, and forming an outer layer on the intermediate layer, the hose body being untreated and formable; preparing a mandrel and fitting a portion of the hose body on the mandrel; deforming a portion of the hose body corresponding to the molding portion of the mandrel into a shape following a contour of the mandrel to obtain a tubular hose body; an outer mold including a groove, wherein the outer mold is compressed radially onto the hose body fitted on the mandrel so as to sandwich the hose body between the outer mold and the mandrel, such that the tubular hose body is deformed into groove of the mold and the molding portion of the mandrel, creating a clamp guide; and treating the tubular hose body to obtain the final form of the hose. Another method embodiment further includes the steps of: providing a molding portion of the mandrel with an annular groove, the groove being of an outer diameter smaller than the inner diameter of the tubular hose body of the straight interior wall; deforming a portion of the hose body corresponding to the molding portion into a shape following a contour of the groove to obtain a tubular hose body including an inwardly projecting circumferential sealing rib. In another method embodiment wherein the mandrel is hollowed out and provided with suction channels extending radially through the molding portion for communication between a hollow portion of the mandrel and an inside of the hose body fitted on the mandrel, applying a negative pressure to the hose body through the hollow portion and the suction channels so as to suction the hose body onto the mandrel to deform the hose body. Once the inner layer and outer layer are formed, the hose may be further treated by either vulcanizing or heating the hose body to cure and solidify the hose into its final shape.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings in more detail, the reference numeral1generally designates a reinforced hose with a clamp guide according to the present invention. Referring now toFIGS. 1, 2, 6-9, the hose1generally comprises a reinforcement intermediate layer12, an outer cover layer14, and an inner layer16. In forming the hose1of the present invention, the individual layers may be applied to form a hose1having a diameter substantially equal to the normal inside diameter of a clamp9,9′, or9″. The inner layer16may be formed by extrusion of an elastomeric material in a tubular construction, and may include suitable additives along with a lubricant or a friction liner coating applied to the inner surface to enable ease of handling during forming operations. The details of these component layers12,14, and16are further discussed below along with their method of assembly generally in the order of assembly.

Referring toFIGS. 1 and 2, the illustrated hose1has a multilayered construction comprising a fabric or woven textile intermediate layer12, an outer rubber layer14on an outer surface13of the intermediate layer12, and an inner layer16with an inner surface17on an inner surface11of the intermediate layer12. In one embodiment, the intermediate layer12can be laid into the inner layer16, and an extrusion process forces the inner rubber layer16into intimate contact with the intermediate woven or braided reinforcement layer12. That is, the inner layer16will be forced into interstices15of the reinforcement layer for contact with the intermediate layer12and/or into contact with portions of the intermediate layer that may extend into and/or through the reinforcement as a result of a braiding process. The result is the creation of an integral bond between the intermediate and inner layers12and16upon subsequent curing of the two layers. In addition, the reinforcement layer12will be embedded in and thereby mechanically locked between the resultant integrally joined intermediate and inner layers12and16. In this embodiment, the outer layer14may be joined with an outer surface18of the inner layer16as the intermediate layer12is absorbed into the inner layer16.

In the illustrated embodiment, the inner layer16along with the intermediate layer12, constituting a middle layer, and the outer layer14, extend through an entire length of the hose, from one end19to an opposite end19′ in an axial direction A (FIG. 4) of the hose10. The intermediate layer16may be a seamless woven textile fiber jacket, with threads20thereof forming the fiber jacket.

The inner rubber layer16, the intermediate layer12, and the outer rubber layer14are made of or constructed of various materials or combinations thereof. More specifically, the inner layer16and outer layer14may be formed of materials such as NBR or nitrile butadiene rubber (acrylonitrile content being equal to or greater than 30% by mass), NBR with PVC (polyvinyl chloride), a class of fluorelastomers known as FKM, such as Viton (DuPont trademark), hydrogenated acrylonitrile butadiene rubber (H-NBR), ethylene propylene diene monomer (EPDM), and other types of materials and combinations thereof. Typical materials may also include various nylons, polyvinyl chlorides, polyethylene, polypropylene, or fluoroplastics. The primary criteria for selecting the material of the inner layer or core16is high resistance to permeation of the fluid of interest. The primary purpose of the outer layer14is to produce a cover, an insulator, or to keep the intermediate layer from vibrating out of the inner layer. Wall thicknesses of the inner layer16and the outer layer14are appropriate for the application and environment in which the hose is intended to be used.

For the intermediate layer12as a middle fabric layer, materials such as textile wire, synthetic textile fiber, spiral wrapped fabric, or woven textile jackets are preferably used. The intermediate layer may be spun, knitted, stockinette knitting, or circularly woven and may be interleaved into the inner layer16. The immediate layer12is a reinforcing layer which increases the ability of the hose1to contain liquids and/or gases under pressure. The type of material used depends on the levels of pressure and temperature of the liquids with which the hose1is intended to be used.

Referring toFIG. 2, reference numeral24indicates a mandrel made of a rigid material, usually metal. The mandrel24has a molding portion25with an outer surface26of a shape corresponding to a contour of an inner surface17of the hose1, such as a cylindrical shape with a substantially constant diameter. As shown in theFIG. 2, the mandrel24has a annular contour or groove27that goes about the circumference of the mandrel.

In a production method using the elements illustrated inFIG. 2, first, the middle fabric layer12, the outer rubber layer14, and the inner rubber layer16, are successively laminated on one another, as by extrusion, to obtain an elongated straight tubular body portion10. The tubular body10is cut to a desired length and, thereby, a tubular hose body10with a straight wall is formed21that is elastically deformable and unvulcanized.

An end19of the tubular hose body10, as formed in this manner, is fitted on the mandrel24and is deformed into a shape following a contour of the outer surface26of mandrel24. Simultaneously, a portion of the tubular hose body10corresponding to the groove27of the mandrel24is deformed into a shape following the groove27, thereby forming an annular sealing rib32, without deforming the outer layer14. An annular rib tip33has an inner diameter less than the diameter of the inner surface17of the inner layer16. In this embodiment, the tubular hose body10can be fitted onto the mandrel24relatively smoothly without encountering significant resistance from a molding portion25of the mandrel24, since an outer diameter28of molding portion25of the mandrel24does not exceed an inner diameter of the inner layer16of a straight-walled portion21of the hose body10. One of the purposes of the mandrel24is to prevent sag of the materials of all three layers12,14, and16of the hose body10. It should be understood that the mandrel24may be implemented in multiple sections to serve the purpose of creating at least one sealing rib32and preventing sag.

Reference numeral38indicates an outer mold that includes an annular groove or recess40to be placed on the outer layer14of the tubular hose body10. An inner cylindrical surface39of an end41of the outer mold38terminates adjacent the outer layer14of the hose body10. The purpose of the annular recess40is to deform the hose10and create at least one clamp guide43on an outer surface14′ of the outer layer14in spaced relation to the end19of the hose body10for the purpose of facilitating the location of a clamp9for sealing off the interior22of the tubular hose body10. The illustrated hose body10has a pair of axially spaced clamp guides43. The recess40is formed so that the material of the uncured tube10can flow into the recess40of the outer mold28without deforming the straight walled portion21or the inner layer16of the hose10.

As shown inFIG. 2, the outer mold28is pressed radially inwardly onto the tubular hose body10that is fitted on the molding portion25of the mandrel24. A portion21of the tubular hose body10is sandwiched by and between the mandrel24and the outer mold28. The portion21of the tubular hose body10is deformed into a shape following the groove27of the mandrel and the recess40of the outer mold28to form at least one clamp guide43and a sealing rib32in the tubular hose body10.

The tubular hose body10positioned on the mandrel24and surrounded by the outer mold28is vulcanized by heating the mandrel24and mold28for a predetermined time to form the hose1. Afterwards, the outer mold28is opened and removed from the hose1and the mandrel24is slid out of and removed from the hose1. The result is a hose1of multilayer construction including the intermediate fabric layer12, and the inner layer16with an annular sealing rib32, and the outer layer14with the clamp guide43. It should be noted at the opposed end19′ (FIG. 4) of the hose body10, this process can be repeated.

In another embodiment, the mandrel may include inlet and outlet ports or bores (not shown) to supply steam or fluid pressure. Steam can be introduced into the mandrel24through a supply line to cause the hose1to expand and cure the material or fluid pressure to allow for easy removal. At the completion of the steam curing process, the mold38and mandrel24are removed or dismantled to release the hose1.

According to the present embodiment, it is possible to produce a hose1with a curved portion23and/or23′ by use of a curved mandrel (not shown), as the molding portion25of the mandrel24does not affect the curved portion23of the hose1. It should be understood that the hose1may remain in the outer mold38only long enough to take the desired final form and then removed as a semi-cured state to be cured in another means, such as autoclave. It should also be understood that the mandrel24will need time to cool before treating another hose. The ports (not shown) on the mandrel can allow for cool liquid to flow through and lower the temperature of the mandrel24for another production cycle.

In an alternative production method using elements shown inFIG. 3, a hose101is formed with an internal end stop150to limit the insertion of a fitting into the hose101. The hose101is produced using a mandrel124and an outer mold138in a manner substantially similar to the production of the hose1using the mandrel24and mold38. However, in addition to an annular groove127to form an annular inner sealing rib132with a tip133diameter on an inner surface117of an inner layer116, the mandrel124has a secondary annular groove129to form an annular end stop150with a tip diameter151on the inner surface117of the inner layer116. The illustrated outer mold138has axially spaced circumferential grooves140on an inner surface139thereof to form clamp guides143on an outer surface114′ of an outer layer114of the hose101. The hose101may also have an intermediate reinforcing layer112, substantially similar to the immediate layer12of the hose1.

An end119of the tubular hose body110, as formed in this manner, is fitted on the mandrel124and is deformed into a shape following a contour of an outer surface126of mandrel124. Simultaneously, a portion121of the tubular hose body110corresponding to the first groove127and the second groove129of the mandrel124is deformed into a shape following the grooves127and129, thereby forming the annular sealing rib132from groove127and a stop150from groove129. The material flows into the grooves127and129without loss of material or folding of material, so that the outer layer remains straight but for the clamp guides143, and the inner layer remains straight but for the sealing rib132. The annular rib tip133has an inner diameter less than the inner surface117of the inner layer16, and the stop150has a stop tip151that has a diameter less than that of the sealing rib tip133. The stop150runs parallel with the sealing rib132and is spaced from the end119, depending on the fitting to be used with the hose10. As in the previous embodiment, the tubular hose body110of can be fitted onto the mandrel124relatively smoothly without encountering significant resistance from a molding portion125of the mandrel124, since an outer diameter of molding portion125of the mandrel124does not exceed an inner diameter122of the inner layer116of a straight-walled portion121of the hose110. One of the functions of the mandrel124is to prevent sagging of the materials of all three layers112,114, and116of hose body110. It should be understood that the mandrel124may be implemented in multiple sections to serve the purpose of creating at least one sealing rib132, as well as, preventing sagging.

As shown inFIG. 3, the outer mold128is pressed radially inwardly onto the tubular hose body110that is fitted onto the molding portion125of the mandrel124, a portion of the tubular hose body110corresponding the straight-walled portion121being sandwiched by and between the mandrel124and the outer mold128. This portion of the tubular hose body110is deformed into a shape following the grooves127and129of the mandrel124and the groove140of the outer mold128to form a clamp guide143, a sealing rib132, and a stop150in the tubular hose body110.

After being formed to shape, the tubular hose body110may be vulcanized, as by heating the mandrel124and mold138a predetermined time to form the completed hose101. After that, the outer mold128may be opened and removed from the hose101and the mandrel124removed. The result is a hose101of multilayer construction including the intermediate layer112, the inner layer116with the sealing rib132and end stop150, and an outer layer114with the clamp guides143. It should be noted that at an opposite end of the hose110, this process can be repeated.

FIG. 5shows relevant steps of a method for producing the hose1as seen inFIG. 2, whileFIG. 6shows the relevant steps of a method for producing the hose1inFIG. 3.

InFIG. 5, a method according to the present invention is illustrated for producing a hose1with multilayer construction including the intermediate fabric layer12, the inner layer16with the sealing rib32, and an outer layer14with the clamp guides43. In step200, an elongated and straight tubular rubber hose body10is formed, as by extrusion, and the tubular rubber hose body10is cut to a predetermined length to obtain a straight tubular rubber hose body10that is not cured or vulcanized (or is only semi-vulcanized). In step201, the hose body10is fitted on a mandrel10having the circumferential sealing rib groove27, such that the tube10is deformed into a desired shape. In step202, an outer mold38with a pair of circumferential clamp guide grooves40is applied to the hose body10. In step203, the tubular rubber hose body10is vulcanized while on the mandrel24and within the mold38by heating for a predetermined time. In step204, when vulcanization is completed, the hose body10may removed from the mold38and mandrel24and may be washed.

InFIG. 6, a method according to the present invention is illustrated for producing the hose101with multilayer construction including the intermediate layer112, the inner layer116with the sealing rib132and end stop150, and the outer layer with the clamp guides143. In step301, elongated tubular hose body110is formed, as by extrusion, and then cut to a predetermined length to obtain the hose body110that is not cured or vulcanized (or is only semi-vulcanized). In step302, the hose body110is fitted onto the mandrel124that has the sealing rib groove127and the end stop groove129. In step303, the outer mold138with the clamp guide grooves140is applied to the hose body110. In step304, the hose body110is vulcanized while on the mandrel124and within the mold138by heating for a predetermined time. In step305, when vulcanization is completed, the outer mold138is opened and the mandrel124is removed to provide the finished hose body110, which may then be washed.

Referring toFIG. 4, the hose1may be of a curved shape and may have one or more curved portions23or23′ which orient the hose1from an axial direction A to an axial direction B of the hose1. The reference numerals21and21′ indicate a pair of straight-walled portions that extends straight from the curved portion in the axial directions A and B of the hose1. The hose1has straight-walled portions21and21′ on each axial end19,19′ thereof.

In the present embodiment shown inFIG. 4, the straight-walled portions21and21′ include the clamp guides43and43′ projecting radially outwardly with respect to an outer peripheral surfaces14′ of the straight-walled portions21and21′ on the outer layer14of the hose1. The clamp guides43and43′ create annular ribs or beads about the circumference of the outer layer14of the hose1to indicate a preferable location for hose clamps9.

Referring now toFIGS. 4, 7a, and7b, an exemplary hose connection assembly60is shown for use of the hose1for connection fittings. The assembly60includes the hose1, a pair of unaligned fittings61and61′ and hose clamps9and9′, with fitting61extending in a direction A and fitting61′ extending in a direction B. InFIG. 4, the clamps9and9′ are shown prior to installation.

In the illustrated embodiment, the clamps9and9′ each have a cylindrical body65and65′ which terminates at one end66and66′. The cylindrical body65and65′ of the clamps9and9′ begin with an inner diameter44and44′ at least slightly greater than the outer diameter of the hose1. InFIG. 8a, clamp9is shown as a worm drive type of clamp. InFIG. 8b, clamp9′ is shown as a spring or tension type of clamp. InFIG. 8c, clamp9″ is shown as an ear and fastener type of clamp. As shown inFIG. 2, the sealing rib32is positioned between the clamp guides43. Thus, the clamp guides43indicate an optimum location for the clamp9to compressively engage the sealing rib32with the surface of the fitting61or61′. As shown inFIG. 9, the hose1may include a plurality of sealing ribs32which are positioned between the clamp guides43.

As seen inFIG. 4, an insert portion63of the fitting61is intended to be inserted into the interior17A of the hose1at end19, and an insert portion63′ of the fitting61′ is intended to be inserted into the interior of the hose1at end19′. In the illustrated embodiment, an outer surface67of the insert portion63has at least one circumferential groove69, which is positioned to mate with a radially inwardly protruding sealing rib32on the inner surface of the inner layer16of the hose1.

After the hose1is positioned over the insert portion63of the fitting61, the clamp9is positioned between the clamp guides43such that, as the clamp9is circumferentially tensioned, the hose1is compressed into sealing engagement with the insert portion63directly over the sealing rib32. The clamp guides43indicate the optimum location for the clamp9, as shown inFIG. 7a. As the hose1is crimped, the sealing rib32becomes firmly anchored onto the outer surface65of the insert portion63of the fitting61. The formation of a fluid-tight seal between the hose1and fitting61is not only is facilitated by the illustrated groove69of the insert portion63of the nipple61and its relation to the inner sealing rib32of the hose1, but also by the crimping of the clamp9.

In reference toFIG. 7b, the fitting61′ extends in the direction B. The fitting61′ has an insert portion63′ which can be inserted into the interior of the hose1at the end19′. When the insert portion63′ has been inserted a sufficient depth, it engages an end stop50(FIG. 3). It is foreseen, that at this point a sealing rib may engage a groove similar to the groove69. In this position, a clamp9′ is positioned between clamp guides43′ and is circumferentially crimped so as to radially inwardly compress the hose1into sealing engagement of the insert portion63′. The clamp guides43′ indicate the optimum location of the clamp9′.

The hose connection assembly60is particularly adapted for coupling with fittings of radiator equipment in automotive applications, such as diesel trucks. The illustrated service fitting connections61and61′ includes portions63and63′ having an industry standard contour.