Abstract:
A fluid conduit includes a flexible member having a tubular wall and a plurality of geometric segments located adjacent to the tubular wall. The geometric segments are disposed about a central axis of the conduit and spaced apart relative to each other to define a gap therebetween. The gap is sized to be closed by contact between adjacent geometric segments upon a predetermined flexure of the flexible member. A method of forming the conduit includes forming a flexible member with a tubular wall and forming a plurality of grooves about the central axis in the tubular wall. The geometric segments in one embodiment are formed from the intersections of a first plurality of helical grooves formed at a first angle relative to the central axis and a second plurality of helical grooves formed at a second angle mutually opposite from the first angle.

Description:
This application claims the benefit of U.S. Provisional Application No. 61/787,749, filed Mar. 15, 2013, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to fluid conduits and, more particularly, to flexible hoses. 
     BACKGROUND 
     Flexible hoses are widely utilized in a wide variety of industrial, household, and commercial applications. One commercial application for hoses are garden or water hoses for household or industrial use. For instance, the hoses are used for watering grass, trees, shrubs, flowers, vegetable plants, vines, and other types of vegetation, cleaning houses, buildings, boats, equipment, vehicles, animals, or transfer between a fluid source and an appliance. For example, the appliance can be a wash stand, a faucet or the like for feeding cold or hot water. Another commercial application for hoses are automotive hose for fuel delivery, gasoline, and other petroleum-based products. Another application for hoses are vacuum cleaner hoses for household or commercial applications. For instance, the hoses are used with vacuum cleaners, power tools, or other devices for collecting debris or dispensing air. Fluids, such as beverages, fuels, liquid chemicals, fluid food products, gases and air are also frequently delivered from one location to another through a flexible hose. 
     Flexible hoses have been manufactured for decades out of polymeric materials such as natural rubbers, synthetic rubbers, thermoplastic elastomers, and plasticized thermoplastic materials. Conventional flexible hoses commonly have a layered construction that includes an inner tubular conduit, a spiraled, braided, or knitted reinforcement wrapped about the tubular conduit, and an outer cover. 
     Kinking and collapsing are problems that are often associated with flexible hoses. Kinking is a phenomenon that occurs, for example, when the hose is doubled over or twisted. A consequence of kinking is that the flow of fluid through the hose is either severely restricted or completely blocked. Kinking becomes a nuisance and causes a user undue burden to locate and relieve the kinked portion of the hose. 
     There have been previous attempts to make hoses more resistant to kink, crush, collapse, and/or burst by incorporating a spiral or helical reinforcement strip into the outer tubular layer of the hose. This construction, however, has often made these reinforced hoses unduly stiff because the embedded helix lacks the ability to flex freely. This construction in some cases has often required thicker and more rigid inner tubular layers. What is needed, therefore, is a reinforced fluid conduit in which the structural reinforcement is readily customizable to suit the different performance needs of its users. 
     SUMMARY 
     A fluid conduit in one embodiment includes a flexible member having a tubular wall configured to convey a fluid, the tubular wall defining a central axis extending through the flexible member, and a plurality of geometric segments disposed adjacent to the tubular wall, the geometric segments disposed circumferentially about and longitudinally along the central axis and spaced apart relative to each other to define a gap therebetween, the gap sized to be closed by contact between adjacent geometric segments upon a predetermined flexure of the flexible member. 
     A fluid conduit in another embodiment includes a flexible member having a tubular wall configured to convey a fluid, the tubular wall defining a central axis extending through the flexible member, and a plurality of geometric segments disposed adjacent to the tubular wall, the geometric segments defined by a first plurality of spaced helical grooves formed in the tubular wall at a first angle relative to the central axis and a second plurality of spaced helical grooves formed in the tubular wall at a second angle relative to the central axis, the first angle and the second angle being mutually opposite with respect to the central axis. 
     A method of forming a fluid conduit includes forming a flexible member with a tubular wall, the tubular wall defining a central axis extending through the flexible member, and forming a plurality of geometric segments adjacent to the tubular wall, the geometric segments disposed circumferentially about and longitudinally along the central axis and spaced apart relative to each other to define a gap therebetween, the gap sized to be closed by contact between adjacent geometric segments upon a predetermined flexure of the flexible member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a section cut through a portion of a flexible fluid conduit having a structural layer formed in accordance with the present disclosure; 
         FIG. 2  is a perspective view of the structural layer of  FIG. 1 ; 
         FIG. 3  is a side plan view of the structural layer of  FIG. 1 ; 
         FIG. 4  is an auxiliary view of a one geometric unit of a plurality of geometric units forming the structural layer; 
         FIG. 5  is a section cut through the geometric unit of  FIG. 4  along line A-A; 
         FIGS. 6-8  are section cuts through three embodiments of a conduit having the structural layer of  FIG. 1  positioned differently in each embodiment; 
         FIGS. 9-13  are front plan views illustrating alternative methods to alter an intermediate layer of the conduit to form the geometric units of the structural layer; 
         FIG. 14  is a perspective view showing the structural layer formed by positioning the geometric units on a mesh liner; 
         FIG. 15  is a front plan view showing the structural layer formed by positioning the geometric units on the conduit; 
         FIG. 16  is a front plan view showing two of the mesh liners of  FIG. 12  positioned on respective inner and outer surfaces of the intermediate layer to form the structural layer; 
         FIGS. 17-21  are section cuts through the conduit of  FIG. 1  depicting the interaction between adjacent geometric units of the structural layer when the conduit is bent; 
         FIGS. 22-26  are section cuts through the conduit of  FIG. 1  illustrating how dimensional changes to the features of the structural layer impact the flexibility of the conduit when the conduit of is bent; 
         FIGS. 27-29  are section cuts through the conduit of  FIG. 1  illustrating how the flexibility and compressibility of the intermediate layers and the geometric units of the structural layer effect the flexibility of the conduit; 
         FIGS. 30-31  are section cuts through a portion of the conduit having a portion of an intermediate layer embedded between the geometric units of the structural layer; and 
         FIG. 32  is a perspective view of a portion of the structural layer of  FIG. 1  showing the interaction of the geometric units after the conduit is bent. 
     
    
    
     DETAILED DESCRIPTION 
     For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the disclosure is thereby intended. It is further understood that the disclosure includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the disclosure as would normally occur to one skilled in the art to which this disclosure pertains. 
       FIG. 1  shows a straight portion of flexible fluid conduit  100  sectioned along its central axis  102 . The conduit  100  includes an outer liner  106  and inner liner  104  that forms a flow path through the conduit  100 . In the embodiment shown, the conduit  100  further includes a structural layer  108  positioned between the inner and outer liners  104 ,  106 . The structural layer  108 , as discussed in more detail below, is configured to prevent the restriction of fluid flow along the flow path due to bending or kinking of the conduit  100 . 
     As best shown in  FIGS. 2 and 3 , the structural layer  108  is formed from a plurality of spaced geometric units  110  positioned circumferentially about the central axis  102 . For purposes of this disclosure, the central axis  102  of the structural layer  108  and the central axis  102  of the conduit  100  are coincident, and any further reference to “central axis” refers to both axes. In the embodiment shown, each geometric unit  110  is formed in the shape of an elongated diamond and has a peripheral gap  111  formed between each adjacent geometric unit in the plurality of geometric units  110 . In other embodiments, the gap  111  is vacuum or air filled. The consecutive gaps between the adjacent geometric units  110  of the structural layer  108  enable the structural layer  108  to flex and to extend and compress axially. As discussed in more detail below, it is the interaction between the spaced adjacent geometric units in the plurality of geometric units  110  that enables the structural layer  108  to reduce restrictions in the flow path when the conduit  100  is subjected to a collapsing or bending force. 
     The geometric units  110  are formed from any flexible, semi-flexible, or rigid material that enables practical reproduction of the geometric units  110  in an intended shape and size. Although the geometrics units  110  of  FIGS. 2 and 3  are shown as elongated diamonds, other geometric shapes are possible. In some embodiments, for example, the geometric units are circular, square, or triangular. The size, number, and spacing of the geometric units  110  are also variable. 
       FIG. 4  depicts an auxiliary view of one geometric unit of the plurality of geometric units  110  when the structural layer  108  is viewed from the arrow  113  of  FIG. 3 .  FIG. 5  shows a cross section of the geometric unit  110  of  FIG. 4  taken along line A-A with the section line oriented perpendicular to a pair of parallel side edges  114  of the one geometric unit  110 . In the embodiment shown, the geometric unit  110  has a rectangular cross section with a constant width W and a constant height H. In other embodiments, however, the width W and the height H of the cross section can vary across the plurality of geometric units  110 . 
       FIGS. 6-8  show three embodiments  116 ,  117 ,  118  of a conduit with the structural layer  108  at a different position on the conduit in each embodiment. The conduit of each of the embodiments includes an inner liner  104 , a woven sleeve  120 , a foamed liner  122 , and an outer liner  106  each radially positioned from inside to outside about the central axis  102 . In the embodiments shown, the woven sleeve  120  is depicted as a one-dimensional line between adjacent conduit layers. The structural layer  108  in each embodiment is at a different position within the conduit. For example,  FIG. 6  shows the structural layer  108  positioned on the exterior of the conduit  116  adjacent to the outer liner  106 .  FIG. 7  shows the structural layer  108  of the conduit  117  positioned between the inner liner  104  and the woven sleeve  120 .  FIG. 8  shows the structural layer  108  positioned within the interior of the conduit  118  adjacent to the flow path on the inside and the inner liner  104  on the outside. The embodiments of  FIGS. 6-8  show the conduit as comprising five layers with the structural layer  108  positioned at three different locations within these layers. In other embodiments, the conduit can include lesser or greater numbers of layers with the structural layer  108  positioned between any of the provided layers. 
     The structural layer  108  in some embodiments is free to move or float rotationally around and/or axially along the central axis  102  of the conduit regardless of its position within the conduit. In other embodiments, the structural layer  108  is bonded to one or more adjacent layers of the conduit to restrict its relative movement about or along the central axis  102 . The bonding of the structural layer  108  in these embodiments can be accomplished by any practical method. In one embodiment, an adhesive is used to secure the structural layer  108  to one or more of the adjacent conduit layers. In some embodiments in which movement of the structural layer  108  is at least partially restricted, the structural layer  108  and at least one adjacent layer are integrated into a single layer. The integration of the structural layer  108  and the at least one adjacent layer can be accomplished as part of an extrusion process that forms the adjacent layer or by altering the adjacent layer after the extrusion process. 
       FIGS. 9-13  schematically illustrate methods to alter the adjacent layer  123  for integration with or formation of the structural layer  108 .  FIG. 9 , for example, depicts the use of a tool  124 , such as a laser, to thermally remove portions of the adjacent layer  123  to form each of the geometric units  110  of the structural layer  108 . In other embodiments, the use of the laser  124  can modify a portion of the material from the adjacent layer  123  to release the structural layer  108 . In some embodiments, the tool  124  forms the geometric units  110  by a non-thermal, non-contact method. The tool  124  in these embodiments directs an effect such as a frequency pulse, air wave, ripple effects or the like at the adjacent layer  123  to form each of the geometric units  110  of the structural layer  108 . 
       FIG. 10  shows the use of a tool  125 , such as one or more rollers, to form the geometric units  110  on the adjacent layer  123 . In this embodiment, the rollers  125  form the geometric units  110  on the adjacent layer  123  while the adjacent layer  123  is still soft. In some embodiments, such as the embodiment of  FIG. 12 , the tool  125  is a rolling tool used on the adjacent layer  123  to relieve or remove material from the adjacent layer  123 , depending on the application, to create the geometric units  110 . The tool  125  in some embodiments is rotated about the adjacent layer  123  in the direction of arrow  126  to form the geometric units  110 . In other embodiments, a plurality of tools rotate about the adjacent layer  123  in opposite directions to form the geometric units  110 . In other embodiments, the rolling tool  125  is fixed and the adjacent layer  123  is rotated in the direction of arrow  127  to form each of the geometric units  110  of the structural layer  108 . 
       FIG. 11  depicts the use of one or more cutters  128  to remove material from the adjacent layer  123  after the extrusion process. In one embodiment implementing the cutters  128 , the cutters  128  are circular cutters. In some embodiments, such as the embodiment shown in  FIG. 13 , a fixed cutting tool  129  is used and the adjacent layer  123  is rotated about the fixed cutting tool  129  to form the geometric units  110 . The tool can be, for example, a rotating padding tool, a blade or scribing tool ( FIG. 13 ), or the like, or any combination thereof. 
     In each of the methods depicted in  FIGS. 9-13 , the adjacent layer  123  is extruded to a thickness that allows approximately half of the thickness of the adjacent layer  123  to be compressed or removed to form the geometric units  110  of the structural layer  108 . In some of these embodiments, less than approximately half of the thickness of the adjacent layer is compressed or removed to form the geometric units  110 . 
       FIGS. 14-16  schematically depict methods to form the structural layer  108  of the conduit by positioning the geometric units  110  on the adjacent layer  130 .  FIG. 14 , for example, shows the geometrics units  110  attached to a mesh strip  131 . In this embodiment, the mesh strip  131  is wrapped around and bonded to the adjacent layer  130  to form the structural layer  108 .  FIG. 15  shows the geometric units  110  bonded directly to the adjacent layer  130  without the use of a substrate, such as the mesh strip  131  of  FIG. 14 .  FIG. 16  shows the adjacent layer  130  with a first plurality of geometric units  132  attached to a first mesh and a second plurality of geometric units  133  attached to a second mesh. In this embodiment, the first mesh is bonded to an inner surface  135  of the adjacent layer  130  and the second mesh is bonded to an outer surface  137  of the adjacent layer  130  to form multiple structural layers. 
       FIGS. 17-21  schematically depict the interaction between adjacent geometric units  110  of the structural layer  108  when the conduit  100  of  FIG. 1  is bent.  FIG. 17  shows the conduit  100  of  FIG. 1  having a downward bend along its central axis  102 . In the embodiment of  FIG. 17 , the downward bend of the conduit  100  produces an outer bend  134  along the conduit  100  above the central axis  102  and an inner bend  136  along the conduit  100  below the central axis  102 . 
     For purposes of this disclosure, the relative directions “down”, “downward”, or “downwardly” refer to a direction pointing toward the bottom of the drawing sheet and the relative directions “up”, “upward”, or “upwardly” refer to a direction pointing toward the top of the drawing sheet. Similarly, the terms “bottom” or “below” refer to relative positions closer to the bottom of the drawing sheet and the terms “top” or “above” refer to relative positions closer to the top of the drawing sheet. 
     The following subscripts are used in conjunction with the letter X to denote the various geometric unit-to-geometric unit gap distances shown in the figures: (s)=straight conduit, (d)=downward bent conduit, (o)=outer bend position, (i)=inner bend position, (t)=tip gap between adjacent geometric units, and (b)=base gap between adjacent geometric units. For example, the gap distance X dot  refers to the gap measured on a downward bent conduit (the subscript “d”) at the outer bend position (the subscript “o”) at the tip of the geometric units (the subscript “t”). 
       FIG. 18  shows two adjacent geometric units  110  positioned above the inner liner  104  at the approximate position of the outer bend  134  before the conduit  100  is bent. In the straight conduit of  FIG. 18 , the side edges  114  of the adjacent geometric units  110  are parallel with respect to each other. Accordingly, the gap between the geometric units  110  at the base of the geometric units  110  or the base gap X sob  and the gap between the geometric units  110  at the tip of the geometric units  110  or the tip gap X sot  are equal. In other words, the base gap X sob  and the tip gap X sot  can be collectively referred to as the straight gap X so  of the straight conduit at the position of the outer bend  134 . When the conduit  100  is bent downward at the outer bend  134  as depicted in  FIGS. 17 and 19 , the base gap of the bent conduit X dob  is approximately equal to or greater than the straight gap of the straight conduit X so . The tip gap of the bent conduit X dot , however, is typically greater than the straight gap of the straight conduit X so  since the adjacent geometric units  110  rotate away from each other as the inner liner  104  bends downward. 
       FIG. 20  shows two adjacent geometric units  110  positioned below the inner liner  104  at the approximate position of the inner bend  136  before the conduit  100  is bent. In the straight conduit of  FIG. 20 , the side edges  114  of the adjacent geometric units  110  are parallel with respect to each other. Accordingly, the gap between the geometric units  110  at the base of the geometric units  110  X sib  and the gap between the geometric units  110  at the tip of the geometric units X sit  are equal. In other words, the base gap X sib  and the tip gap X sit  can be collectively referred to as the straight gap X si  of the straight conduit at the position of the inner bend  136 . 
     When the conduit  100  is bent downward at the inner bend  136  as depicted in  FIGS. 17 and 21 , the base gap of the bent conduit X dib  is approximately equal to or less than the straight gap of the straight conduit X si . The tip gap of the bent conduit X dit , however, can range from slightly less than the straight gap of the straight conduit X si  to zero. In other words, after a predefined amount of bending, the tips of the geometric units  110  at the inner bend  136  contact each other and provide a positive stop to prevent further bending of the conduit  100  at positions adjacent to the contacting geometric units  110 . The geometric unit-to-geometric unit contact between each of the adjacent geometric units in the plurality of geometric units  110  prevents the conduit  100  from collapsing into the flow path and substantially restricting the fluid flow therethrough. 
       FIG. 22  shows two adjacent geometric units  110  positioned above the inner liner  104  at an inner bend  136  of the conduit  100  after the conduit  100  of  FIG. 1  has been bent upwardly (not shown). The adjacent geometric units  110  have a height H, a width W, a base gap X, and form a contact angle A having its vertex at the contact point of the geometric units  110 . The maximum contact angle A formed between each of the adjacent geometric units in the plurality of geometric units  110  is one of a number of factors that determines the relative amount of bend of the conduit  100  over its length. 
     As shown by comparing  FIGS. 22 and 23 , reducing the base gap between the adjacent geometric units  110  from X to X′ while holding constant the height H c  and the width W c  of the geometric units  110  reduces the contact angle from A to A′ and, therefore, reduces the overall amount of bend in the conduit  100 . The contact angle A′ is reduced because the reduction in the base gap between the adjacent geometric units  110  moves the effective pivot points of the geometric units  110  closer together as the conduit  100  bends in the upward direction. Accordingly, the geometric units  110  rotate less before the tips of the geometric units  110  contact each other. If the base gap X between the adjacent geometric units  110  of  FIG. 23  is increased, the contact angle A similarly increases, allowing more overall bend in the conduit  100  before the tips of the geometric units  110  contact each other. 
     As shown by comparing  FIG. 22  and  FIG. 24 , reducing the height of the adjacent geometric units  110  from H to H′ while holding constant the base gap X c  between the geometric units  110  and the width W c  of the geometric units  110  increases the contact angle from A to A″ and, therefore, increases the overall amount of bend in the conduit  100 . The contact angle A″ is increased because the reduction in the height of the adjacent geometric units  110  allows the geometric units  110  to rotate further about their effective pivot points before the tips of the geometric units  110  contact each other. If the height H of the adjacent geometric units  110  of  FIG. 24  is increased, the contact angle A decreases, allowing less overall bend in the conduit  100  before the tips of the geometric units  110  contact each other. 
     As explained with reference to  FIGS. 25 and 26 , reducing the width of each of the geometric units  110  from W ( FIG. 25 ) to W′ ( FIG. 26 ) while holding constant the base gap X c  between the geometric units  110  and the height H c  of the geometric units  110  results in more flex regions  140  between the geometric units  110  for the same overall length of conduit  100 . Increasing the number of flex regions along the length of the conduit increases the overall flexibility of the conduit because the cumulative length of the conduit capable of flexing increases with each added flex region  140 . 
     As shown in  FIGS. 27 and 28 , a reduction in the flexibility of the liner  104  can reduce the overall flexibility of the conduit  100 . In a straight conduit, the base gaps between the geometric units  110  in each of  FIGS. 27 and 28  are equal. The highly flexible inner liner  104  of  FIG. 27  allows the maximum distance between the effective pivot points of the geometric units  110  in the bent conduit. In contrast, the more rigid inner liner  104 ′ of  FIG. 28  reduces the distance between the effective pivot points in the geometric units  110  in the bent conduit. In particular, a line  142  connecting the effective pivot points of the geometric units  110  of  FIG. 27  falls along the path of the inner liner  104 , indicating that the line  142  represents the maximum distance between the effective pivots points. In contrast, a line  144  connecting the effective pivot points of the geometric units  110  of  FIG. 28  does not fall along the path of the inner liner  104 ′ due to the reduced flexibility of the inner liner  104 ′. 
       FIG. 29  illustrates the effect that the compressibility of the geometric unit material has on the contact angle between the adjacent geometric units  110 . In the embodiment shown, the material at the contact point  146  between the two adjacent geometric units  110  is slightly deformed due to the compression of the material. For purposes of this disclosure, the term “non-deformed contact angle” refers to the angle formed when adjacent geometric units first make contact at the contact angle  146 , but before either of the geometric units begins to deform. The term “fully-deformed contact angle” refers to the angle formed after adjacent geometric units have made contact at the contact point  146  and after both of the geometric units are fully deformed. As the geometric units  110  become more compressible, especially at their tip, the difference between the non-deformed contact angle and the fully-deformed contact angle increases between the adjacent geometric units  110 , resulting in more overall flexibility in the conduit. The converse is also true. That is, as the geometric units  110  become less compressible, the difference between the non-deformed contact angle and the fully-deformed contact angle decreases between the adjacent geometric units  110 , resulting in reduced overall flexibility in the conduit. 
       FIGS. 30 and 31  illustrate the effect that integration of the structural layer  108  with another layer has on the flexibility of the conduit  100 .  FIG. 30  depicts two adjacent geometric units  110  in a straight section of the conduit  100 . The geometric units  110  are adjacent to the inner liner  104  and integrated with the outer liner  206 . The gap between the adjacent geometric units  110  is occupied by the material of the outer liner  206 .  FIG. 31  shows the two adjacent geometric units  110  after the conduit  100  of  FIG. 30  has been upwardly bent. In this embodiment, as the geometric units  110  come together due to the bending of the conduit  100 , the portion  210  of the outer liner  206  between the geometric units  110  is compressed. The density of the outer liner material, therefore, determines how close the geometric units  110  can get to each other. Bending of the conduit  100  in the opposite direction causes the outer liner material to stretch between the geometric units  110 . 
       FIG. 32  shows the interaction among five geometric units  110  of the structural layer  108  when the conduit  100  of  FIG. 1  is bent. Although each of the geometric units  110  is shown interacting with adjacent geometric units substantially along its side edges  114 , the interaction among the geometric units  110  can also occur as point contacts. For example, the adjacent geometric units  110  in some embodiments can make point contact at or near respective perimeter vertexes  148  instead of edge contact along the side edges  114 . In some embodiments, the adjacent geometric units  110  can interact as a combination of point contact at the perimeter vertexes  148  and edge contact along the side edges  114 . Various factors can effect whether or not adjacent geometric units  110  interact as point contact or edge contact. For example, in some embodiments, the relative amount of twist along different portions of the conduit  100  effects the type of contact between the adjacent geometric units  110  at each different portion of the conduit  100 . 
     The geometric reinforced fluid conduit of the present disclosure is suitable for automotive, household, commercial, aerospace, medical, and industrial uses. The plurality of geometrical reinforcement members enable the structural layer to flex and to extend and compress axially. 
     While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the disclosure are desired to be protected.