Patent Publication Number: US-2005136203-A1

Title: Hose assembly having varied reinforcing layers

Description:
FIELD OF THE INVENTION  
      The present invention relates generally to hose assemblies, and more particularly to braided, reinforced hydraulic brake hose.  
     BACKGROUND OF THE INVENTION  
      Reinforced hydraulic hose is well known in industry for use in transporting fluids under pressure, particularly in automotive brake hose applications. These hose assemblies generally comprise a polymeric core hose layer and one or more reinforcing layers formed from strands of fiber or wire material that are braided over the core layer. In most applications, the hose also includes an intermediate hose layer formed over the core hose layer and a first reinforcing layer. A second reinforcing layer is thereafter braided over the intermediate hose layer. Finally, a polymeric cover material is generally formed over the second reinforcing layer to complete the hose assembly.  
      The reinforcing layers of conventional hydraulic hose assemblies are generally applied by rotary braiding machines such as those described in U.S. Pat. Nos. 4,266,461; 5,099,744; and 5,775,195. Using these rotary braiding machines, strands of fiber or wire reinforcing material are wound upon the hose layers in an interwoven, braided pattern, as known in the art. Generally, the rotary braiding machines are configured to provide a braid pattern wherein the strands are successively passed over and under pairs of oppositely wound strands. This is referred to herein as a 2-over, 2-under braid pattern. In certain applications, it may be desired to further improve hose performance by varying the braid patterns, for example, to optimize burst strength, volumemetric expansion, dynamic life, or coupleability of the hoses.  
      There is thus a need for a hydraulic brake hose which can be formed with reinforcing layers having braid patterns other than the standard 2-over, 2-under braid pattern in both reinforcing layers.  
     SUMMARY OF THE INVENTION  
      The present invention provides a hydraulic brake hose having reinforcing layers formed in braid patterns other than conventional 2-over, 2-under patterns in each layer. The braid patterns can be selected to optimize various properties of the hydraulic hose, as may be desired. In an exemplary embodiment, the brake hose comprises a core hose layer, a first reinforcing layer over the core hose layer, an intermediate hose layer over the first reinforcing layer, a second reinforcing layer over the intermediate layer, and an outer hose layer. Each of the first and second reinforcing layers have braid patterns formed in one of a 1-over, 1-under pattern or a 3-over, 3-under pattern. The reinforcing layers may comprise fiber or wire material.  
      In another embodiment, one of the first and second reinforcing layers has a braid formed in a 2-over, 2-under pattern, and the other of the reinforcing layers has a braid formed in one of a 1-over, 1-under pattern or a 3-over, 3-under pattern.  
      In another embodiment, a method of making hydraulic brake hose includes forming a core hose layer, selectively braiding a first reinforcing layer over the core layer in one of a 1-over, 1-under pattern or a 3-over, 3-under pattern, forming an intermediate hose layer over the first reinforcing layer, selectively braiding a second reinforcing layer over the intermediate hose layer in one of a 1-over, 1-under pattern or a 3-over, 3-under pattern, and forming an outer hose layer over the second reinforcing layer.  
      These and other features, objects and advantages of the invention will become more readily apparent to those skilled in the art upon review of the following detailed description, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.  
       FIG. 1  is a perspective view depicting an exemplary hose assembly according to the present invention;  
       FIG. 1A  is an alternative embodiment of an exemplary hose assembly similar the hose assembly of  FIG. 1 ;  
       FIG. 2  is a cross-sectional view of the hose assembly of  FIG. 1 , taken along line  2 - 2 ;  
       FIG. 3  is a cross-sectional view, similar to  FIG. 2 , depicting an alternate embodiment of a hose assembly according to the present invention;  
       FIG. 4  is a perspective schematic view illustrating detail of an exemplary rotary braiding machine; and  
       FIG. 5  is a perspective view depicting another embodiment of a hose assembly according to the present invention. 
    
    
     DETAILED DESCRIPTION  
      Referring to  FIGS. 1 and 2 , there is shown an exemplary hydraulic brake hose assembly  10  according to the present invention. The hose assembly  10  includes a core hose layer or tube  12  formed from polymeric material that is suitable for use in transporting a fluid material for which the hose is intended to be used. As non-limiting examples, the polymeric material may comprise polychloroprene, chlorinated polyethylene acrylonitrile-budtadiene, styrene butadiene, polyisoprene, polybutadiene, ethylene-propylene-diene terpolymers, chlorinated polyethylene, or natural rubber polymers. Alternatively, the polymeric material may comprise thermoplastic elastomers such as propylene modified with ethylene-propylene rubber, such as Santoprene®, available from Monsanto Corporation; block polymers, such as the Kraton® line of polymers available from Shell Chemical Company; polyvinyl chloride, etc. These elastomers may be compounded with other filler, plasticizers, antioxidants, and cure systems to achieve particular properties desired for a given application, as known in the art.  
      A first reinforcing layer  14  is formed over the core hose layer and comprises a plurality of first and second reinforcing members  16 ,  18  wound in opposite directions around and along the length of the core hose layer  12  in a braided pattern by a rotary braiding machine, as known in the art. The reinforcing members  16 ,  18  may comprise strands of fiber material, such as cotton, rayon, polyester, polyvinyl alcohol, or other suitable fiber material. Alternatively, the reinforcing members  16 ,  18  may comprise strands of metallic material in the form of wire. In the embodiment shown in  FIG. 1 , the first and second reinforcing members  16 ,  18  of the first reinforcing layer  14  are braided in a pattern such that each first reinforcing member  16  crosses over an oppositely wound second reinforcing member  18 , then passes under an adjacent, oppositely wound reinforcing member  18  in succession. This braid pattern is referred to herein as a 1-over, 1-under braid pattern.  
      The hose assembly  10 , further includes an intermediate hose layer  20  formed over the first reinforcing layer  14 , generally by extruding the intermediate hose layer  20  over the core hose layer  12  and first reinforcing layer  14 . A second reinforcing layer  22  is then formed over the intermediate hose layer  20  and has first and second reinforcing members  24 ,  26  wound around and along the intermediate hose layer  20  in opposite directions, in the manner described above for the first reinforcing layer  14 . In the embodiment shown in  FIG. 1 , the second reinforcing layer  22  is braided such that each first reinforcing member  24  passes successively over and under three of the oppositely wound second reinforcing members  26 . This braid pattern is referred to herein as a 3-over, 3-under braid pattern.  
      The hose assembly  10  may further include an outer hose layer  30  formed over the second reinforcing layer  22 , generally by extruding the outer layer  30  over the second reinforcing layer  22 . The outer hose layer  30  protects the hose assembly  10  and is formed from a polymeric material suited for use in an application for which the hose assembly  10  will be used. As a non-limiting example, the outer hose layer may be formed from any of the various polymeric materials described above for the core hose layer  12 .  
      While the exemplary hose assembly  10  of  FIGS. 1 and 2  has been shown and described herein as having a first reinforcing layer  14  with a 1-over, 1-under braid pattern, and a second reinforcing layer  22  with a 3-over, 3-under braid pattern, it will be recognized that either the first or second reinforcing layers  14 ,  22  may alternatively be formed with a conventional 2-over, 2-under braid pattern. For example,  FIG. 3  depicts a cross-section of an alternative hose assembly  10   a  wherein the first reinforcing layer  14  has a 1-over, 1-under braid pattern and the second reinforcing layer  22   a  has a 2-over, 2-under pattern. In another embodiment, the first and second reinforcing layers  14 ,  22  can have braid patterns selected from one of a 1-over, 1-under pattern; a 2-over, 2-under pattern; or a 3-over, 3-under pattern. Accordingly, the braid patterns for the first and second reinforcing layers  14 ,  22  may be selected to have any of these braid patterns whereby various combinations of first and second reinforcing layer braid patterns may be produced.  
       FIGS. 1-3  depict hose assemblies wherein the reinforcing members  16 , 18 ,  24 ,  26  of the first and second reinforcing layers  14 ,  22  comprise single strands of fiber or wire material. Alternatively, each reinforcing member  16 ,  18 ,  24 ,  26  may comprise a plurality of strands, as known in the art. For example,  FIG. 1A  is a detail view of a 3-over, 3-under braid pattern similar to the second reinforcing layer  22  of hose assembly  10  in  FIG. 1 ., but wherein each of the first and second reinforcing members  24 ,  26  comprise three strands of fiber or wire material  24   a ,  24   b ,  24   c  and  26   a ,  26   b ,  26   c.    
      Advantageously, the particular braid pattern combination desired may be selected to optimize various properties of the hose assembly  10 , such as burst strength, volumemetric expansion, dynamic life, or coupleability. The desired braid pattern may be selected by adjusting a cam on the rotary braiding machine used to form the reinforcing layers  14 ,  22 . Referring to  FIG. 4  for example, in the rotary braiding machine disclosed in U.S. Pat. No. 5,099,744, a cam  40  and cam follower  42  control the motion of a pivotable arm  44  such that an end of the arm moves up and down to form the over-under patterns in the braid. To create the varied braid patterns, a small cam can be substituted for cam  40  when it is desired to form a 1-over, 1-under pattern. Similarly, a larger cam may be substituted when it is desired to form a 3-over, 3-under braid pattern. Accordingly, the cams are relatively easily changed to alter the braid pattern formed by the machine, whereby the same machine may be utilized to create various braid patterns as discussed above.  
      In another embodiment, depicted in  FIG. 5 , a hose assembly  10   b  may be formed as described above, except that an intermediate hose layer is not formed over the first reinforcing layer  14 . Rather, the second reinforcing layer  22  is formed directly over the first reinforcing layer  14 . Alternatively, an adhesive (not shown) may be applied over the first reinforcing layer  14  prior to forming the second reinforcing layer  22  over the first reinforcing layer  14 .  
      According to another aspect of the invention, a method of making a hydraulic brake hose assembly  10  comprises forming a core hose layer  12 , selectively braiding a first reinforcing layer  14  over the core hose layer  12  in one of a 1-over, 1-under pattern; a 2-over, 2-under pattern; or a 3-over, 3-under pattern. An intermediate hose layer  20  is formed over the first reinforcing layer  14 , and a second reinforcing layer  22  is selectively braided over the intermediate hose layer  20  in one of a 1-over, 1-under pattern; a 2-over, 2-under pattern; and a 3-over, 3-under pattern. Finally, an outer hose layer  30  may be formed over the second reinforcing layer  22  to complete the hose assembly  10 .  
      While the present invention has been illustrated by the description of an embodiment thereof, and while the embodiment has been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the general inventive concept.