Abstract:
A conduit includes a multilayer wall including an outer layer having a first color; an intermediate layer having a second color; and an inner layer having a third color, wherein the intermediate layer is between the outer layer and the inner layer, and the first color, the second color, and the third color are different. Each of the first color, the second color, and the third color indicates a level of wear of the multilayer wall when one of the first color, the second color, or the third color is exposed due to wear or abrasion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35. U.S.C. §119, based on U.S. Provisional Patent Application No. 61/497,273 filed Jun. 15, 2011, the disclosure of which is hereby incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    Conduits, such as single layer conduits, are typically used in automation and robotic applications to connect components associated with machines or robots. Unfortunately, a conduit gradually wears down due to abrasions caused by friction between the conduit and other machine or robotic components. Eventually, if unnoticed by an operator, conduit failure and stoppage of a machine or a robot can occur. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is a diagram illustrating an exemplary embodiment of a corrugated conduit; 
           [0004]      FIG. 2A  is a diagram illustrating a multilayer wall of the corrugated conduit depicted in  FIG. 1 ; 
           [0005]      FIG. 2B  is a diagram illustrating an exploded view of the multilayer wall depicted in  FIG. 2A ; 
           [0006]      FIG. 3  is a diagram illustrating an exemplary table pertaining to colors, wear indicators, and layer indicators of a multilayer wall; and 
           [0007]      FIG. 4  is a diagram illustrating another exemplary embodiment of a corrugated conduit having a multilayer wall. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0008]    The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention. 
         [0009]    According to an exemplary embodiment, a conduit comprises a multilayer wall that provides an integrated wear indicator. The integrated wear indicator comprises multiple layers in which each layer is of a distinctive color, as described further below. According to an exemplary embodiment, the multiple layers include three layers: an outer layer, an intermediate layer, and an inner layer. According to other embodiments, the multiple layers include two layers, or more than three layers (e.g., four layers, five layers, etc.) in which there may be an outer layer, multiple intermediate layers, and an inner layer. According to an exemplary implementation, each layer may have a substantially uniform thickness that extends the length of the conduit. According to an exemplary implementation, the conduit may have a tubular form or some other shape (e.g., a flat conduit, etc.) suitable for the particular application of use. 
         [0010]    According to an exemplary embodiment, the conduit is a corrugated, multilayer conduit. According to another exemplary embodiment, the conduit is a non-corrugated, multilayer conduit. 
         [0011]    According to an exemplary embodiment, the color of a layer provides information pertaining to a degree of wear associated with the conduit. For example, if an intermediate layer of a yellow color is exposed due to wear, the yellow color may indicate that the conduit has undergone significant wear. According to another example, if an inner layer of a red color is exposed due to wear, the red color may indicate that the conduit has undergone critical wear and should be replaced. 
         [0012]    According to an exemplary embodiment, the color of a layer provides information pertaining to an amount of remaining wall thickness associated with the conduit. For example, if an intermediate layer of a yellow color is exposed due to wear, the yellow color may signify that 40-50% of the original wall thickness (e.g., the original, aggregate of thickness provided by the multilayer wall) associated with the conduit has eroded (e.g., assuming the intermediate layer constitutes 10% of the original wall thickness). According to an exemplary embodiment, the thickness of a layer and/or the material used for the layer may be customized based on customer requirements. In this regard, the color of the layer can provide a quantitative measurement (e.g., inner and outer bounds, a range of numerical values, etc.) of erosion or wear which permits an operator to determine what, if any action will be taken, based on an exposed color of a layer. 
         [0013]    According to an exemplary embodiment, the color of each layer is to be distinctive relative to other layers. While various colors (e.g., black, yellow, orange, green, red, white, purple, blue, combinations thereof, etc.) may be used to indicate the degree of wear and/or the amount of remaining wall thickness, preferably the color of each layer is optically contrasting. In this way, an operator via visual inspection or an optical device (e.g., a color identification device) may identify an exposed color of a layer associated with the conduit. 
         [0014]      FIG. 1  is a diagram illustrating an exemplary embodiment of a conduit  100 . According to an exemplary embodiment, conduit  100  may be used for dynamic applications (e.g., robotic applications, controlled axes, automation applications, and other motion-intensive applications) in which persistent movement and/or frequent flexural stress may occur. According to such applications, conduit  100  may be used to protect cables, hoses, wires, and/or other types of lines that may be encased by conduit  100 . As illustrated in  FIG. 1 , conduit  100  may take the form of a corrugated conduit comprising ridges  105  and grooves  110 . As described further below, conduit  100  comprises a multilayer wall  115 , as illustrated in  FIG. 2A . 
         [0015]    According to other embodiments, conduit  100  may be used for other types of applications, such as, static applications, general machine applications, transit-related applications, mining applications, marine applications, mechanical engineering applications, or electrical installations. Depending on, among other things, the type of application, the material used for multilayer wall  115  may be different from the material described herein. That is, a particular application may require that conduit  100  have certain properties or meet certain specifications pertaining to, for example, flexibility, crush resistance, flexural fatigue, fire resistance, chemical resistance, temperature, and/or other properties/specifications known in the art. However, according to such other embodiments, conduit  100  comprises the multilayer wall, as described herein. 
         [0016]    According to an exemplary embodiment, as previously described, conduit  100  may be used for dynamic applications. According to such an embodiment, conduit  100  may comprise of materials, such as, nylon 12 grades (e.g., polyamide (PA) 12 or PA 12), thermoplastic polyurethanes (TPUs), thermoplastic elastomers (TPEs) (e.g., thermoplastic polyester elastomers, thermoplastic polyamides, etc.), other types of thermoplastic elastomers, or flexible polymer grades (e.g., modified polypropylene or the like). 
         [0017]    According to an embodiment, as illustrated in  FIG. 2B , multilayer wall  115  includes an outer layer  120 , an intermediate layer  125 , and an inner layer  130 . The thickness of each layer depicted in  FIG. 2B  is exemplary. According to other implementations, the relative thickness of outer layer  120 , intermediate layer  125 , and inner layer  130  may be different depending on, among other things, customer requirements, standards in the industry, etc. The thickness of multilayer wall  115  may also depend on the size of conduit  100 . By way of example, the size of conduit  100  may correspond to nominal width (NW)17, NW23, NW29, NW36, NW48, NW56 or NW70. Additionally, depending on the material used (e.g., in terms of density, strength, etc.), the thickness of multilayer wall  115  may vary (e.g., approximately ±20%). 
         [0018]    Outer layer  120 , intermediate layer  125 , and inner layer  130  may be composed of any of the materials previously described. For example, outer layer  120  may be composed of a soft, wear resistant and highly flexible material, such as a TPU or a very flexible material with good tension strength, such as PA 12. The material for outer layer  120  may include tribological modification (e.g., wear reduction). Intermediate layer  125  may be composed of PA  12  or some other compatible material (e.g., a glue, a TPU, etc.) relative to outer layer  120  and inner layer  130 . According to an exemplary embodiment, intermediate layer  125  may serve as a connecting layer that bonds outer layer  120  and inner layer  130  together. Inner layer  130  may be composed of a higher tension and compression strength relative to outer layer  120 , such as a PA 12polymer. The material for inner layer  130  may include tribological modification (e.g., friction reduction). 
         [0019]    Each layer of multilayer wall  115  is a distinctive color. By way of example, outer layer  120  may be black, intermediate layer  125  may be yellow or orange, and inner layer  130  may be red. According to other embodiments, the color of outer layer  120 , intermediate layer  125 , and/or inner layer  130  may be different. According to an exemplary embodiment, each layer of multilayer wall  115  is opaque. 
         [0020]    As previously described, the color of a layer provides information pertaining to a degree of wear associated with the conduit. Additionally, or alternatively, the color of a layer provides information pertaining to an amount of remaining wall thickness associated with the conduit.  FIG. 3  is a diagram illustrating an exemplary table  300  pertaining to the colors of multilayer wall  115 . 
         [0021]    As illustrated, table  300  includes a layer field  305 , a color field  310 , a wear indicator field  315 , and a layer indicator field  320 . Layer field  305  indicates a layer of multilayer wall  115  (e.g., outer layer  120 , intermediate layer  125 , and inner layer  130 ). Color field  310  indicates the color of a layer (e.g., black, yellow, and red). Wear indicator field  315  indicates a level of wear of multilayer wall  115  (e.g., none or minimum level of wear, a significant level of wear, a critical level of wear). Additionally, or alternatively, the level of wear may provide information pertaining the time period for replacement. By way of example, when the color yellow of intermediate layer  125  is exposed, this could indicate to an operator to check this portion of conduit  100  again within 1 month. According to another example, when the color red of inner layer  130  is visible, this could indicate to an operator to replace conduit  100  between 1 and 7 days. Layer indicator field  320  indicates a quantified measurement (e.g., a percentage or some other numerical value) of remaining thickness of multilayer wall  115 . For example, when the black color of outer layer  120  is visible, the overall thickness of multilayer wall  115  is between 51%-100%; when the yellow color of intermediate layer  125  is visible, the overall thickness of multilayer wall  115  is between 36%-50%; and when the red color of inner layer  130  is visible, the overall thickness of multilayer wall  115  is between 1%-35%. 
         [0022]    The values (i.e., range of percentages) indicated in layer indicator field  320  are exemplary. According to other embodiments, the ranges may be different depending on the thickness of each layer relative to the aggregate thickness of multilayer wall  115 . By way of example, for outer layer  120 , the range of percentages may be between 5%-70%; for intermediate layer  125 , the range of percentages may be between 5%-20%; and for inner layer  130 , the range of percentages may be between 5%-70%. Also, according to other embodiments, the values may correspond to other types of numerical values (e.g., fractions, decimals, etc.) or may be represented graphically (e.g., a colored pie chart, etc.) or pictorially. As an example, according to an exemplary implementation, the packaging associated with conduit  100  may include the wear indication information and/or the layer indication information in any of these forms (e.g., a table, a diagram, a chart, numerical ranges, warning information, etc.). 
         [0023]      FIG. 4  is a diagram illustrating another exemplary embodiment of a conduit  400  comprising a multilayer wall  425 . As illustrated, conduit  400  is a corrugated conduit comprising four layers: an outer layer  405 , a first intermediate layer  410 , a second intermediate layer  415 , and an inner layer  420 . Each layer of multilayer wall  425  may be composed of one of the materials previously described. The relative thickness of each layer is exemplary. Outer layer  405 , first intermediate layer  410 , second intermediate layer  415 , and inner layer  420  may each be of a distinctive color. Each layer of multilayer wall  425  may be opaque, etc., as previously described with respect to conduit  100 . Similar to the discussion above, when each layer ( 405 - 420 ) is visible, an operator will be able to determine the wear status and/or the layer status of conduit  400 . This will allow the operator to take appropriate action, such as, replacing conduit  400  before a failure occurs. 
         [0024]    The foregoing description of embodiments provides illustration, but is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Accordingly, modifications to the embodiments described herein may be possible. 
         [0025]    The terms “a,” “an,” and “the” are intended to be interpreted to include one or more items. Further, the phrase “based on” is intended to be interpreted as “based, at least in part, on,” unless explicitly stated otherwise. The term “and/or” is intended to be interpreted to include any and all combinations of one or more of the associated items. 
         [0026]    In the specification and illustrated by the drawings, reference is made to “an exemplary embodiment,” “an embodiment,” “embodiments,” etc., which may include a particular feature, structure or characteristic in connection with an embodiment(s). However, the use of the phrase or term “an embodiment,” “embodiments,” etc., in various places in the specification does not necessarily refer to all embodiments described, nor does it necessarily refer to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiment(s). The same applies to the term “implementation,” “implementations,” etc. 
         [0027]    Although the invention has been described in detail above, it is expressly understood that it will be apparent to persons skilled in the relevant art that the invention may be modified without departing from the spirit of the invention. Various changes of form, design, or arrangement may be made to the invention without departing from the spirit and scope of the invention. Therefore, the above-mentioned description is to be considered exemplary, rather than limiting, and the true scope of the invention is that defined in the following claims.