Abstract:
A moldable plastic guard for use in a protective guard for a conduit such as a hoses, tubing, wire, cable, and fiber optics. The guard is receivable over the surface of the conduit and is attached to a nut. The nut may be used to join the end of the conduit to a fitting or other connection.

Description:
CROSS-REFERENCE TO RELATED CASES  
       [0001]     The present application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/624,791; filed Nov. 3, 2004, the disclosure of which is expressly incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates broadly to protective guards for conduit such as hose, tubing, wire, cable, and fiber optics, and more particularly to a moldable, plastic guard for use as a corrosion-resistant, weight saving replacement for the wire spring guards conventionally used in airbrake tubing coil applications.  
         [0003]     When conduit such as hose, tubing, wire, cable, or fiber optics is exposed to certain environmental conditions, physical obstacles, or human abuse, the portion of the conduit so exposed may be protected with an external guard or armor. Such guards typically are formed as a coiled steel wire spring or, alternatively, as an elongate plastic or rubber sleeve or spiral. The coil, sleeve, or spiral is configured as having an inner diameter which is sized to be marginally larger than the outer diameter of the wire or conduit to allow the guard to be installed coaxially over the hose or wire. Guards or armor of such type are shown in commonly-assigned U.S. Pat. Nos. 6,494,496; and in U.S. Pat. Nos. 6,604,758; 5,857,711; 5,816,622; 5,608,963; 5,346,290; 5,277,227; 4,967,799; 4,876,810; 4,805,933; 4,602,808; 4,446,607; 4,406,852; and 3,926,141; Des. 356,858; and European Pat. Appln. Nos. 824,205; and 655,377. A plastic guard is manufactured by WABCO (Westinghouse Air Brake Co.) GmbH of Hannover, Germany.  
         [0004]     Typical applications of guards and coils of such type include the protection of hydraulic hose in construction machinery or plant equipment, and of airbrake tubing coils in tractor trailers rigs and other vehicles. Hoses, tubing, fittings, and other components for these applications are described further in commonly-assigned U.S. Pat. Nos. 6,098,666; 5,024,468; 4,335,908; 4,302,036; 4,288,113; 4,188,051; 4,136,897; 3,907,335; 3,830,531; and in U.S. Pat. Nos. 5,918,640; 5,232,645; 4,009,734; and 3,977,440; and U.K. Pat. Appln. GB 2,239,503. Certain of such components are manufactured commercially by Parker-Hannifin Corporation of Cleveland, Ohio, through its Parflex Division of Ravenna, Ohio, and its Brass Products Division of Otsego, Mich., and by Tectran, Inc., of Mississauga, Ontario, Canada.  
         [0005]     Each of the guard types heretofore known in the art offer varying degrees of strain relief and/or cut, crush, abrasion, or kink resistance. In general, steel wire springs offer good kink and abrasion resistance. However, as being formed of a metal, springs are subject to corrosion, have a tendency to scratch paint and other finishes, and are relatively heavy which may impact their use in certain mobile applications. When employed at the connected end of a hose or tubing assembly, the spring conventionally is locked to the end fitting which usually is provided as a multi-component including a body, nut, ferrule, and insert.  
         [0006]     Plastic or rubber sleeves or spirals conventionally are manufactured by either extrusion, molding, or spiraling, and are known to be generally lightweight and corrosion resistant. In particular, extruded guards offer long, continuous lengths, but the raw materials suited for extrusion generally are considered to be either too flexible to prevent kinking, or too rigid to prevent flexing of the hose without breaking or kinking the guard absent the addition of strain relief slots. Spiral guards, typically provided as strips of plastic thermoformed about a mandrel into a helical shape, also offer long, variable lengths, but generally do not afford appreciable kink resistance. Molded guards, however, can be formed with the rigidity necessary to prevent kinking.  
         [0007]     In view of the foregoing, it is believed that continued improvements in guard constructions, and particularly in molded constructions, for wire and conduit tubing coil assemblies would be well-received by the transportation, construction, and other industries involved.  
       BROAD STATEMENT OF THE INVENTION  
       [0008]     The present invention is directed to a protective guard for conduit such as hose, tubing, wire, cable, and fiber optics, and more particularly to a guard and an assembly therefor for use as a replacement for the wire spring guards conventionally used in airbrake tubing coil applications.  
         [0009]     Such guard may be molded or otherwise formed of plastic material which may be both corrosion-resistant and lightweight, and further which may be selected to provide sufficient rigidity to prevent kinking and to offer good abrasion resistance. Advantageously, the guard may be adapted for a push-on, threaded, or other connection to the nut which is used for the connection of the end of the coil or other tubing within the given application. Such nut, in turn, may be configured to accommodate such connection.  
         [0010]     These and other advantages will be readily apparent to those skilled in the art based upon the disclosure contained herein. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:  
         [0012]      FIG. 1  is a partial cross-sectional view of a representative airbrake coil or other tubing assembly including a guard and fitting having a nut in accordance with the present invention;  
         [0013]      FIG. 2  is a side view of the guard of  FIG. 1 ;  
         [0014]      FIG. 3  is a longitudinal cross-sectional view of the guard of  FIG. 2  taken through line  3 - 3  of  FIG. 2 ;  
         [0015]      FIG. 4  is a side view of an alternative embodiment of the guard of  FIG. 1 ;  
         [0016]      FIG. 5  is a longitudinal cross-sectional view of the guard of  FIG. 4  taken through line  5 - 5  of  FIG. 4 ; and  
         [0017]      FIG. 6  is a radial cross-sectional view of the nut of the fitting of  FIG. 1 . 
     
    
       [0018]     The drawings will be described further in connection with the following Detailed Description of the Invention.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Certain terminology may be employed in the following description for convenience rather than for any limiting purpose. For example, the terms “forward” and “rearward,” “front” and “rear,” “right” and “left,” “upper” and “lower,” “top” and “bottom,” and “right” and “left” designate directions in the drawings to which reference is made, with the terms “inward,” “inner,” “interior,” “inside,” or “inboard” and “outward,” “outer,” “exterior,” “outside,” or “outboard” referring, respectively, to directions toward and away from the center of the referenced element, the terms “radial” or “vertical” and “axial” or “horizontal” referring, respectively, to directions, axes, or planes perpendicular and parallel to the longitudinal central axis of the referenced element. Terminology of similar import other than the words specifically mentioned above likewise is to be considered as being used for purposes of convenience rather than in any limiting sense.  
         [0020]     In the figures, elements having an alphanumeric designation may be referenced herein collectively or in the alternative, as will be apparent from context, by the numeric portion of the designation only. Further, the constituent parts of various elements in the figures may be designated with separate reference numerals which shall be understood to refer to that constituent part of the element and not the element as a whole. General references, along with references to spaces, surfaces, dimensions, and extents, may be designated with arrows or underscores.  
         [0021]     For the illustrative purposes of the discourse to follow, the precepts of the guard of the present invention are described in conjunction with its adaptation for an airbrake coil or other tubing used within tractor/trailer rigs or other vehicles for supplying air pressure from a source to the airbrake system of the vehicle. In view of the discourse to follow, however, it will be appreciated that aspects of the present invention may find utility for protecting other fluid conduits used in variety of hydraulic, pneumatic, or other applications involving coiled or straight runs of tubing, hose, wire, cable, fiber optics, or the like. Use with those other such conduits and applications therefore should be considered to be expressly within the scope of the invention herein involved.  
         [0022]     Referring then to the figures wherein corresponding reference characters are used to designate corresponding elements throughout the several views with equivalent elements being referenced with prime or sequential alphanumeric designations, shown generally at  10  in  FIG. 1  is a representative embodiment of a guard assembly according to the present invention. Such assembly  10  includes a protective guard,  20 , which is sheathed coaxially over the exterior surface,  22 , of one end,  23 , of an airbrake coil or other length of tubing,  24 . The end  23  of the coil or other tubing length  24  may be coupled to an associated fitting or other connection, referenced generally at  26 , via a nut,  27 , which may be formed of a metal, plastic, or other material of construction, and to which the guard  20  may be interference fit or otherwise connected. Such fitting  26  may have an associated fitting body,  28 , and a sleeve or ferrule,  29 .  
         [0023]     In basic construction, guard  20  includes a generally flexible, elongate, tubular body,  30 . Although a single body or segment  30  is shown, it should be appreciated that two or more bodies  30  may be joined together, such as in the manner described in commonly assigned U.S. Pat. No. 6,494,496.  
         [0024]     As may be seen best with additional reference to the views of  FIGS. 2 and 3 , body  30  extends longitudinally along a central axis,  32 , intermediate a first end,  34 , and a second end,  36 , which define a length, referenced at “λ” in the cross-sectional view of  FIG. 3 , of the guard  20  therebetween. With reference particularly to the cross-sectional view of  FIG. 3 , the body  30  has an radial inner surface, referenced generally at  38 , including an end portion,  40 , at the body first end  34  having a first inner diametric extent, referenced at “d 1 ,” with the remainder,  42 , of the surface  38  having a second inner diametric extent, referenced at “d 2 .” For the connection of the guard  20  to the nut  27  of the fitting  26 , the dimension d 1  may be sized so as to accommodate the receiving of the body first end  34  over a complementary end portion of the nut  27 , with the dimension d 2  being sized to be marginally larger than the outer diameter of the tubing  24  or otherwise to fit more closely over the exterior surface  22  thereof.  
         [0025]     The body  30  of guard  20  may be molded of a synthetic rubber material such as Buna N, neoprene, or a thermoplastic blend. However, for increased rigidity and correspondingly improved kink resistance, body  30  may be molded of a resilient plastic material, which may be filled, i.e., reinforced, or unfilled, such as a poly(ether ether ketone), polyimide, polyamide, polyolefin, polyetherimide, polybutylene terephthalate, fluoropolymer, polyvinyl chloride, polysulfone, polyester, acetal homo or copolymer, a TPEs such as a thermoplastic polyurethane (TPU), thermoplastic olefin (TPO), thermoplastic vulcanizate (TPV), or copolyester thermoplastic elastomer (COPE) or polyamide TPE, or a copolymer, blend, mixture, laminate, composite, or other combination of one or more of the foregoing materials. Typically, the plastic or other material of construction for the molding or other forming of the guard  20  may have a hardness of between about 85 Shore A and about 65 Shore D.  
         [0026]     With continuing reference to  FIGS. 1-3 , it may be seen in the illustrated airbrake coil or other tubing application that the outer surface,  50 , of body  30  may be configured at a first segment,  52 , adjacent the first end  34  thereof as having an increased wall thickness, referenced generally at “t” ( FIG. 3 ) relative to the remaining second segment,  54 , thereof, so as to be relatively rigid or otherwise less flexible as compared to the segment  54 . In this regard, the segment  52 , which also may be rounded as shown or otherwise contoured, thereby may function as an integral, hand-graspable lever or handle. Such handle advantageously may be used in place of the more complicated and expensive handle arrangements heretofore used in the “gladhand” connection of airbrake coils to the vehicle air supply. “Gladhand” connections and conventional handles of the type herein involved are further described in U.S. Pat. Nos. 5,918,640; 4,634,151; 4,366,965; and 4,226,103. The segment  52  may terminate as shown at the body first end  34 , with the body second end  36  terminating, as shown, at a boss,  56 , surrounding the body second end  36 .  
         [0027]     The remaining second segment  54  of the body  30  may be formed, for example, as having strain relief slots or a stepped wall thickness, or as shown, as otherwise having a decreasing, i.e., tapered, wall thickness so as to exhibit a minimum bend radius or other degree of flexibility. In this way, the segment  54  may be made to resiliently conform to the bending of the tubing while delimiting such bending beyond the minimum bend radius of the tubing to prevent kinking.  
         [0028]     Looking now momentarily to the several views of  FIGS. 4 and 5 , an alternative embodiment of guard  20  of  FIGS. 2 and 3  is referenced generally at  20 ′. In the embodiment  20 ′, it may be seen that the segment  52 , now reference at  52 ′, is shortened such as if a glandhand end should not be required.  
         [0029]     Returning to  FIG. 1 , as mentioned, for the connection of the guard  20  to the nut  27  of the fitting  26 , the dimension d 1  of the body inner radial surface  38  is sized at  40  so as to accommodate the receiving of the body first end  34  over a complementary end portion of the nut  27 . In this regard, and with reference now to the cross-sectional view of the nut  27  shown in  FIG. 6 , nut  27 , which may be of a generally annular configuration as having a bore,  60 , extends along a central longitudinal axis,  62 , intermediate a forward end,  64 , and a rearward end,  66 . Nut  27  has an inner radial surface,  68 , which defines the bore  60 , and an outer radial surface,  70 , which, with the inner radial surface  68 , defines the wall, referenced at  72 , of the nut therebetween. As may be seen with momentary reference to  FIG. 1 , in the assembly  10 , the nut axis  62  is aligned coaxially with the axis  32 .  
         [0030]     Returning to  FIG. 6 , in the illustrated embodiment, the outer radial surface  70  of the nut  27  is configured at the forward end  64  having hexagonal or other flats portions,  74 , for rotational engagement with a wrench or other tool for make-up or disassembly, and at the rearward end  66  as having an engaging portion,  76 , for the engagement of the guard first end  34  therewith in the attachment of the guard  20  ( FIG. 1 ) to the nut  27 . In this regard, the engaging portion  76  may be configured as having one or more rearwardly-facing barbs or other projections,  78   a - b.  Such barbs  78   a - b  define the radial outermost diametric extent, referenced at D, of the nut engaging portion  76 , and are sized relative to the first inner diametric extent d 1  of the guard body first end portion  40  ( FIG. 2 ) so as to allow such portion to be pushed-on, such as by hand or otherwise, over the engaging portion  76 , thereby attaching the guard  20  to the fitting nut  27 .  
         [0031]     In the case of the guard  20  being formed of a plastic or other resilient material, the extent D may be provided to be marginally larger than the first inner diametric extent d 1  of the guard body first end portion  40  ( FIGS. 1 and 2 ) so as to allow for the incremental expansion of the body end portion  40  upon insertion, of the engaging portion  76  thereinto and the subsequent relaxation thereof compressively retaining the end  34  of the body  30  on the end  66  of the nut  27 . In addition, the diametric extent of the remainder of the engaging portion  76  from which the barbs  78  extend may be sized relative to the diameter of the flats portion  74  so as to provide an annular space, referenced at “s” in  FIGS. 1 and 6 , which may approximate the wall thickness of the tubing  24 . In this way, when the tubing end  23  is sheathed over the nut engaging portion  76 , a generally continuous, smooth surface appearance may be achieved as between the tubing exterior surface  22  and the flats portion  74 .  
         [0032]     Advantageously, the inter-engagement of the barbs  78  and the body first end portion  40  ( FIG. 1 ) may be used to prevent the guard  20  from being inadvertently pulled off of the nut  27  by hand. Alternatively, the engaging portion  76  may be externally-threaded, notched, or otherwise configured relative to the complementary configuration of the body first end portion so as to allow for the attachment of the guard  20  to the nut  27 .  
         [0033]     The inner radial surface  68  of the nut  27 , in turn, is configured at the rearward end  66  as having a rearward portion,  80 , which may having a first inner diameter, D 1 , sized such that the outer diameter of the tubing  24  ( FIG. 1 ) therethrough is able to be received therethrough. At the forward end  64 , the nut inner radial surface  68  is configured as having a forward portion,  82 , having a second inner diametric extent, D 2 , which may be the same as or different from D 1 , and which otherwise is sized to internally receive the fitting ferrule  29  ( FIG. 1 ).  
         [0034]     The nut  27  may be threaded so as to be couplable to an end of an associated externally-threaded connection (not shown) for the tubing  24 . For example, in a “female” style embodiment, and is referenced at  84 , the forward portion  82  of the inner radial surface  68  may be internally threaded at the forward terminus thereof. Alternatively, in a “male” style embodiment, the hexagonal flats portion  74  on the nut outer radial surface  70  may be shortened or otherwise moved rearwardly such that the surface may be configured at the forward end  64  as having external threads.  
         [0035]     In whatever style the nut  27  is provided, the nut inner radial surface  68  further may be configured as having an internal, shoulder,  90 , extending radially inwardly relative to the forward portion  82  as disposed intermediate the forward portion and the rearward portion  80 . Such shoulder  90 , which may include a rearwardly-facing chamfer,  91 , to assist in the insertion of the tubing end  23  ( FIG. 1 ) therethrough, defines a third inner diametric extent, D 3 , of the nut inner radial surface  68 . Such extent D 3  may, as shown, be smaller than extents D 1  and D 2 , or, alternatively, may be same or substantially the same as the extent D 1  provided that such extents are smaller than the extent D 2 , or otherwise such that a forwardly-facing thrust surface,  92 , is defined. In any event, the extent D 3  may be marginally larger than the tubing outer diameter such that the tubing end  23  ( FIG. 1 ) may be received therethrough and into abutting engagement with a corresponding end end,  93  ( FIG. 1 ), of the fitting  26 .  
         [0036]     In use, and with additional reference to  FIG. 1 , as the nut forward end  64  is threaded onto the fitting end  93 , the thrust surface  92  may abuttably engage and draw the fitting ferrule  29  ( FIG. 1 ) forwardly into compression against the fitting end. Such compression causes a deformation of the ferrule  29  which, in turn, grippably retains the tubing end  23  in a fluid-tight or other engagement with the fitting end  93 .  
         [0037]     With continuing reference to  FIG. 1 , the assembly  10  may be assembled, for example, by inserting the nut engaging portion  76  into the guard body first end  34  such that the barbs  78  engage the guard body end portion  40 . Thereupon the tubing end  23  may be inserted into the guard body second end  36  and advanced forwardly through the guard  20  and the nut  27  such that the guard and nut are sheathed coaxially over the tubing exterior surface  22 . A rearward facing shoulder or other surface,  94 , of the nut flats portion  74  and/or an end wall,  96 , of the guard body end portion  40  may function as a stop to delimit the forward advancement of the guard  20  over the nut  27 . Of course, the guard  20  and nut  27  alternatively may be sheathed separately over the tubing exterior surface  22 , and thereafter engaged while on the tubing  24 , such as by using the body segment  52  as a handle with which to push the guard end  34  over the nut engaging portion  40  either before or after the nut  27  has been connected to the fitting body  28 .  
         [0038]     As it is anticipated that certain changes may be made in the present invention without departing from the precepts herein involved, it is intended that all matter contained in the foregoing description shall be interpreted in as illustrative rather than in a limiting sense. All references including any priority documents cited herein are expressly incorporated by reference.