Abstract:
The present invention is directed towards an improved flexible hose ( 10 ). The hose ( 10 ) is comprised of at least a flexible material ( 28 ) and a reinforcing rod ( 12 ) positioned externally of the flexible material ( 28 ). Terminal ends ( 16, 18 ) define both the flexible material ( 28 ) and the reinforcing rod ( 12 ). At least one terminal end ( 16 ) of the reinforcing rod ( 12 ) is located short of the terminal ends ( 18 ) of the flexible material ( 28 ), so that the non-reinforced end of the flexible material ( 28 ) forms a soft cuff ( 20 ) adapted to be received by a hose fitting. Also disclosed is an improved method of manufacturing the flexible hose ( 10 ).

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to composite hoses, more particularly to rubber and plastic hoses comprising an outer helically extending reinforcement layer. The hose is constructed to provide for easier coupling of the hose ends and any desired fittings.  
         BACKGROUND ART  
         [0002]    Hoses manufactured with outer helical PVC, nylon, or other plastic-like polymer rod reinforcements are known in the art. Such hoses are also known as drop hoses. Drop hoses are mainly used for the transfer of various fluids, such as gasoline, petroleum based products, chemicals, food products, etc., in tank truck applications. Drop hoses, and similar corrugated hoses, are made by several different manufacturing methods, including those disclosed by U.S. Pat. Nos. 4,383,555, 4,471,813, 4,304,266, 4,012,272, and 3,938,929 and disclosed in WO97/24543. The hose ends are generally later coupled with cam and groove fittings and band clamps.  
           [0003]    Because of the need for a tight fit between a fitting and the hose, the outside diameter of a fitting shank and the inside diameter of the hose are almost identical; the shank is usually a bit larger than the hose ID. The slightly larger shank OD results in deformation of those portions of the hose that are in contact with the shank. Thus a certain force is required to insert the fitting shank into the hose. The force required to insert the shank into the hose increases if the hose is reinforced with a rigid, non-deformable material such as the outer helical PVC rod. To provide the necessary force or to reduce the required force, it is known in the art to apply lubricants to hose, to attempt to soft the PVC prior to insertion in the hose, or apply greater force to the fitting to ensure a proper insertion. All of these methods are time and labor consuming and may be detrimental to the hose or the fitting.  
           [0004]    The configuration of the outer corrugations can also make the insertion of the fittings into the hose bore difficult and make it difficult to install the band clamps over the plastic spiral wire and achieve a leak proof connection without band distortion and damage to the hose or fitting. Over the years, aids have been developed to overcome these situations. One such aid is to place a piece of rope between the outer corrugations of the cover to achieve a flat surface at each end of the hose that will make it easier to install the band clamps and prevent distortion. Another aid is the use of a “banding coil.” A banding coil is a separate spring or coil made out of a plastic-like material that is either screwed or wrapped on the cover and fills the corrugations created by the outer helical wire at each end of the hose. The result achieved by the banding coil is the same as the rope, which is to end up with a flatter surface to install the band clamps. Another aid is the use of a rubber-like sleeve that is slipped over the ends of the hose that also attempts to create a flatter surface.  
           [0005]    The present invention of forming a drop hose with soft cuffed ends eliminates the known problem in the art and eliminates the use of external aids as described above in coupling this type of hose. Many other advantages also arise from the present invention, including easier insertion of the fitting into the hose, reduced labor in coupling the hose, better coupling retention, and a likely reduction of necessary inventory for hose distributors.  
           [0006]    Corrugated rubber or plastic hose with cuffed ends are disclosed in the following patents. U.S. Pat. No. 4,099,744 discloses a hose end formed flat with no corrugations. U.S. Pat. Nos. 5,398,977, 5,497,810, and EP 330894 disclose a plastic cuff inserted over the corrugations. U.S. Pat. No. 3,640,312, discloses an extruded hose end formed without corrugations and U.S. Pat. Nos. 4,456,034, 4,996,741, 4,996,20, 4,295,496, and 4,669,508 all disclose extruded or rubber corrugated hoses with non-corrugated ends which are internally reinforced by helically extending wires placed within the extruded or preformed corrugations. However, the corrugations of these hoses are formed by the extruded layers or by internal helical means, differing from the external helical reinforcing means of the conventional drop hoses. It is the presence of the external helical reinforcing means of the drop hoses which has created the need for the external aids and high force required to apply fittings to the drop hoses.  
           [0007]    However, in the drop hose of the present invention, the corrugations are solely formed by the helically extending outer reinforcement, and the base hose material has a constant internal diameter. While forming cuffs on hose ends is known in the art and the need for a constant outer diameter at the end of drop hoses to provide the hose with fittings has long been recognized in the art, as evidenced by the numerous types of aids used with conventional drop hose ends, forming a drop hose with cuffed ends in the manner of the present invention has not been appreciated or recognized. The present invention is directed toward a solution of a long felt problem in the art and provides the many benefits listed above.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention is directed towards an improved flexible hose. The hose is comprised of at least a flexible material and a reinforcing rod positioned externally of the flexible material. Terminal ends define both the flexible material and the reinforcing rod. At least one terminal end of the reinforcing rod is located short of the terminal ends of the flexible material, so that the non-reinforced end of the flexible material forms a soft cuff adapted to be received by a hose fitting.  
           [0009]    Also disclosed is an improved method of manufacturing the flexible hose of the present invention. The hose is formed by rotating a mandrel while feeding a length of material onto the mandrel to build a hose length on the mandrel, feeding a second length of material in the form of a reinforcing rod onto the mandrel to form a helical reinforcing rod on the hose length and curing the hose length. The improvement in the method of forming the inventive hose is characterized by, prior to feeding the reinforcing rod onto the mandrel, modifying the hose length to create non-adhesive regions.  
           [0010]    Another aspect of manufacturing the inventive hose includes applying a third material to the hose length to create the non-adhesive regions.  
           [0011]    Another aspect of manufacturing the inventive hose lies in the method of applying the reinforcing rod onto the mandrel in the locations of the non-adhesive region. The speed at which the mandrel rotates as the reinforcing rod is feed onto the mandrel at the non-adhesive regions may be reduced, creating a winding with a greater pitch in the non-adhesive regions. Or the tension of the reinforcing rod may be reduced as the reinforcing rod is feed onto the mandrel at the non-adhesive regions.  
           [0012]    Also disclosed is a hose length. The hose length is comprised of at least one elastomeric layer and a reinforcing rod helically wound externally of the elastomeric laver. Periodically spaced along the hose length are non-adhesive regions.  
           [0013]    Another aspect of the disclosed hose length is that the reinforcing rod is not adhered to the elastomeric layer in the non-adhesive region.  
           [0014]    Another aspect of disclosed hose length lies in the application of the reinforcing rod on the elastomeric layer in the locations of the non-adhesive region. The reinforcing rod may be wound onto the elastomeric layer with a reduced pitch than in the adhesive regions. Or the tension of the reinforcing rod may be reduced in the non-adhesive regions. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0015]    The invention will be described by way of example and with reference to the accompanying drawings in which:  
         [0016]    [0016]FIG. 1 illustrates the inventive hose;  
         [0017]    [0017]FIG. 2 is a cross-sectional view of the hose;  
         [0018]    [0018]FIG. 3 illustrates the method of manufacturing the inventive hose;  
         [0019]    [0019]FIG. 4 illustrates a portion of the hose during manufacture. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    The hose  10  of the present invention is illustrated in FIG. 1. The hose  10  has an external reinforcing rod  12  helically wound about a flexible hose base  14 . The reinforcing rod  12  has a terminal end  16  located a distance from the terminal end  18  of the hose base  14 , creating a soft hose cuff  20 . The hose  10  has a constant internal diameter (see FIG. 2), and a minimum and maximum outer diameter created by the corrugation effect of the reinforcing rod  12  and the flexible hose base  14  between the windings of the reinforcing rod  12 . Since the soft cuff  20  is an extension of the flexible hose base  14 , the cuff  20  has an outer diameter corresponding to the minimum outer diameter of the hose  10 .  
         [0021]    An exemplary construction of the hose  10  is illustrated in the cross-sectional view of FIG. 2. The flexible hose base  14  is constructed from a base layer  22 , two reinforcing plies  24 ,  26  and an outer cover layer  28 . The hose base  14  may be provided with a number of layers differing from the illustrated two reinforcing layers  24 ,  26  and other rubber layers in addition to the base layer  22 . The number and type of layers comprising the flexible hose base  14  is dependant upon the desired hose properties as determined by the end use of the hose  10 .  
         [0022]    The base layer  22  is constructed of conventional natural or synthetic thermoelastic vulcanizable material used in the manufacture of hoses. The reinforcing layers  24 ,  26  are also formed of conventional hose reinforcing materials. The cover layer  28  is formed from a thermoplastic or thermoelastic vulcanizable material that is capable of bonding to the base layer  22  and to the reinforcing rod  12  during curing of the hose  10 . Examples of typical materials for the base and cover layers  22 ,  28  include, but are not limited to, nitrile rubber for the base layer  22  and a nitrile rubber/PVC blend for the cover layer  28 . The reinforcing rod  12  is formed from a material that is more rigid and/or has a higher mechanical strength than the cover layer  28 , such as polyvinylchloride. The reinforcing rod  12  may also have an internal reinforcing wire.  
         [0023]    The manufacture of the hose  10  is achieved by spirally winding the various hose layers  12 ,  22 ,  24 ,  26 ,  28 , onto a mandrel  30 , see FIG. 3, to produce a hose length  32  which is then cut into short lengths to produce the inventive soft-cuff hose  10 . More details concerning one method of manufacturing the hose length  32  are disclosed in U.S. Pat. No. 4,856,720, which is incorporated herein by reference. In this method of manufacturing, the hose length  32  is built upon a long, straight circular mandrel  30  that is fixed to rotating drives  34  at each end of the mandrel  30 . The mandrel  30  is supported by roller bearings  36  at approximately every fifteen feet. Parallel to the mandrel  30  is a trolley  38  equipped with material applicators  40 . The material applicators  40  are bobbins provided with the different materials  42  used in the manufacture of the hose length  32 . including rubber, fabric, wire helix, PVC rod, curing tape, and rope.  
         [0024]    The materials  42  used to construct the hose length  32  are applied spirally onto the rotating mandrel  30  as the trolley  38  moves parallel to the mandrel  30 . The hose length  32  is constructed in this manner by applying one layer of material  42  over the proceeding layer. Usually the trolley  38  will apply a layer in a first direction and the next layer in the opposite direction for symmetry and design purposes. For the illustrated hose length  32 , the base rubber layer  22  is first applied to the rotating mandrel  30 , followed by the reinforcing layers  24 ,  26 , and then the cover layer  28 . At this point in the construction of the hose length  32 , a basic softwall rubber hose has been constructed on the mandrel.  
         [0025]    To transform the softwall rubber hose length  32  into the helically reinforced, soft cuffed hose  10  of the present invention the following further steps are taken. At pre-selected regions  46  along the softwall rubber hose length  32 , a material  44  is applied to render the pre-selected region non-adhesive to further layers applied to the hose length  32  in the pre-selected region. The pre-selected positions  46  along the hose length  32  are at locations corresponding to the lengths of the individual hoses  10  to be produced. For example, if twenty foot hoses  10  (including the cuffed ends) with six inch cuffs  20  at each terminal end are desired, a pre-selected non-adhesive region  46  is prepared along the hose length  32  for a length of twelve inches every nineteen feet. So for the entire mandrel length, the first six inches of the hose length  32  is rendered non-adhesive and then the trolley  38 , applying a non-adhesive material  44 , is moved nineteen feet further along the mandrel  30  from the position of the first non-adhesive region  46 . The non-adhesive material  44  is then applied to the softwall rubber hose length  32  for a length of twelve inches to produce two six inch cuffs  20 . The steps of moving the trolley  38  nineteen feet and applying twelve inches of non-adhesive material  44  is repeated along the length of the mandrel  30 . The non-adhesive material  44  may be formed from any non-adhesive material that prohibits the outer rubber layer  28  from curing to the reinforcing rod  12 . Such materials include, but are not limited to, nylon tape, film, or sheets, polyester tape, film or sheets, pre-cured rubber tape, film, or sheets, metallic film or sheets, Teflon film or sheets, or a liquid non-adhesion material.  
         [0026]    After the non-adhesive material  44  is applied in the pre-selected positions, using the trolley  38 , the reinforcing rod  12  is applied to the rotating mandrel  30  and onto the softwall rubber hose length  32 . The reinforcing rod  12  is applied with a constant pitch except over the pre-selected region  46  where the non-adhesive material  44  has been applied, see FIG. 4. As the trolley  38  moves past the pre-selected regions  46  where the non-adhesive material  44  is applied, the speed at which the mandrel  30  rotates is reduced, while the trolley speed is maintained, thus increasing the pitch at which the rod  12  is applied to the mandrel  30 . As illustrated, the hose length  32  on the mandrel  40  has a variably pitched reinforcing rod  12 .  
         [0027]    After the variably pitched reinforcing rod  12  has been applied, a rope  48  is inserted in the spaces formed between the windings of the rod  12 . The rope  48  is applied in the same manner as the reinforcing rod  12 , with an increased pitch at the pre-selected areas  46  where a soft cuff  20  is to be formed on the finished hose  10 . The diameter of the rope  48  is sized to maintain the desired pitching of the reinforcing rod  12  on the hose length  32 . The rope  48  also acts as a mold to hold the hose layers  22 ,  24 ,  26 ,  28  and the rod  12  in place during the curing of the hose length  32 . The rope  48  selected may be a conventional braided rope or a smooth rope; any conventional non-adhesive, flexible cord-type material may be used.  
         [0028]    The hose length  32  is cured to vulcanize the layers  12 ,  22 ,  24 ,  26 ,  28  and create adhesion between the various layers  12 ,  22 ,  24 ,  26 ,  28 , including between the reinforcing rod  12  and the hose cover layer  28 . The rod  12  adheres to the cover layer  28  along the hose length  32 , except where the non-adhesive material  44  has been applied. After the hose length  32  has been cured, the rope  48  is removed. After being removed from the mandrel  30 , the hose length  32  is then cut into the desired final hose lengths. Preferably, the cuts are centered in the pre-selected regions  46  to produce two soft cuffs  20 . The cuts may also be at one of the edges of the pre-selected region  46  if it is desired to form a hose  10  with only a single cuffed end  30 . The portion of the reinforcing rod  12  that is not bonded to the outer cover layer  28  due to the presence of the nonadhesive material  44  is also removed. As a final step, if required, the non-adhesive material  44  is removed from the hose cuffs  20 .  
         [0029]    Due to the curing of the hose length  32  with the rope  48  being wound between the pitched helical windings of the reinforcing rod  12 , and the tension force used to wind the rope  48  onto the mandrel  30 , the flexible hose base  14  creates an indented imprint between the windings of the rod  12 . The imprint from the rope  48  also extends into the soft cuff  20 , creating a slight indent  50  in the soft cuff  30 . The imprint indent  50  in the cuff  30  does not adversely affect the seal needed in applying a fitting to the hose cuff  30 . If the rope  48  has a braided or textured pattern, then the indented imprint will be also have a braided or textured pattern.  
         [0030]    As noted above, the hose  10  is manufactured by spirally winding the hose layers  12 ,  22 ,  24 ,  26 ,  28 , onto a mandrel  30  to produce a hose length  32  which is then cut into short lengths with at least one soft cuffed end  30 . The hose layers  12 ,  12 ,  24 ,  26 ,  28  may be applied to the mandrel  30  by means other than the illustrated traveling trolley  38  and material applicator  40 . The layers  12 ,  22 ,  24 ,  26 ,  28  may be applied by moving a rotating mandrel  30  past a stationary material applicator  40 . The layers  12 ,  22 ,  24 ,  26 ,  28  may also be applied by helically handwinding the material  42  onto either a rotating or stationary mandrel  30 .  
         [0031]    Additionally, after the pre-selected region  46  has been modified to render that portion of the hose length  32  non-adhesive, the reinforcing rod  12  and supporting rope  48  may be applied by methods other than varying the pitch of the rod  12  and the rope  48 . The reinforcing rod  12  may be applied at a constant pitch for the entire hose length  32 , but with a reduced tension in the pre-selected non-adhesive regions  46 . The rope  48 , likewise, would then be applied at a constant pitch but with reduced tension in the pre-selected regions. The reduced tension of the rod  12  and rope  48  prevent the creation of multiple indents in the created soft cuff  20 .  
         [0032]    Since the inventive hose  10  has a terminal end  18  defined by a substantially constant inside and outside diameter for a defined length, it is easier to install any desired fittings to the cuffed hose end without the difficulties experienced with non-cuffed hoses and without needing to use known fitting aids as previously discussed.