Wrappable covered knitted tubular thermal sleeve and method of construction

Abstract

A knitted sleeve (10) and method of construction thereof for providing thermal protection around an elongate member (12) contained therein is provided. The sleeve (10) includes a circumferentially continuous, tubular knitted inner wall (14') that bounds a central cavity (24) extending longitudinally along a longitudinal center axis (26) between opposed open ends (28, 30). The sleeve (10) further includes a knitted outer wall (14") having opposed edges (16, 18) extending longitudinally in generally parallel relationship to the longitudinal center axis (26), one of the opposed edges (16) of the knitted outer wall (14") being integrally knitted with the inner wall (14') and the other opposed edge (18) of the knitted outer wall (14") being wrappable about the inner wall (14') in fixed relationship thereabout.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application Serial No. 63 / 411,709, filed September 30, 2022, and priority to U.S. Application Serial No. 18 / 374,616, filed September 28, 2023, each of which is incorporated by reference in its entirety. [Background technology]

[0002] Background of the Invention 1.Technical Field The present invention relates generally to tubular protective sleeves for providing protection to elongated members contained therein, and more particularly to braided tubular protective sleeves for providing an insulating barrier around high temperature pipes and methods of constructing the same.

[0003] 2. Related technologies Cylindrical sleeves are known for insulating elongated members, such as high-temperature elongated members. Sleeves are typically constructed from heat-resistant yarns, such as silica, fiberglass, ceramic, basalt, aramid, or carbon, to withstand relatively high temperatures. Cylindrical sleeves constructed from such heat-resistant yarns are commonly used to insulate high-temperature pipes, such as those providing conduits for hot liquids or gases, such as exhaust gases, and to suppress heat radiating outward beyond the pipe boundary. While the above-described cylindrical sleeves are typically effective in providing a thermal barrier, the heat-resistant yarns forming the outer wall of the sleeve are susceptible to damage, which can reduce the useful life of the sleeve. Summary of the Invention [Means for solving the problem]

[0004] Summary of the Invention One aspect of the present invention provides a sleeve for providing thermal protection around an elongate member contained therein. The sleeve includes a circumferentially continuous, tubular, braided inner wall that defines a central cavity extending longitudinally along a longitudinal center axis between opposed open ends. The sleeve further includes a braided outer wall, opposed edges of which extend longitudinally between the opposed open ends, one of the opposed edges of the braided outer wall being integrally braided with the inner wall and the other of the opposed edges of the braided outer wall being wrappable around the inner wall in a fixed relationship therewith.

[0005] In another aspect of the invention, the yarns forming the outer wall have greater impact resistance compared to the yarns forming the inner wall.

[0006] In another aspect of the invention, the yarns forming the outer wall are made of at least one of polyester, nylon, polypropylene, polyethylene, acrylic, cotton, and rayon.

[0007] In another aspect of the invention, the yarns forming the inner wall are multifilament mineral fibers.

[0008] In another aspect of the invention, the yarns forming the inner wall are comprised of at least one of silica, fiberglass, ceramic, basalt, slate, slag, aramid, and carbon.

[0009] In another aspect of the invention, an impact resistant layer is provided over the exterior wall.

[0010] In another aspect of the invention, the impact resistant layer forms a circumferentially continuous layer around the inner wall when the outer wall is wrapped around the inner wall.

[0011] In another aspect of the invention, a plurality of fasteners may be secured to the impact resistant layer, and pairs of fasteners are securable to one another to maintain the outer wall in a wrapped relationship about the inner wall.

[0012] In another aspect of the invention, the impact resistant layer is sewn to the outer wall.

[0013] In another aspect of the invention, the interior wall may be knitted with a 2x2 rib knit for improved impact resistance and thermal insulation.

[0014] In another aspect of the present invention, there is provided a method of constructing a tubular textile sleeve for providing a thermal barrier around an elongate member extending therethrough, the method including knitting a circumferentially continuous tubular inner wall having a central cavity extending longitudinally along a central axis between opposed open ends, and knitting an outer wall having opposed edges extending longitudinally in generally parallel relationship to the central axis, one of the opposed edges being integrally knitted with the inner wall such that the outer wall extends away from the inner wall, the outer wall being wrappable around the inner wall to form a sleeve having a double layer wall.

[0015] In another aspect of the invention, the method may further include forming the outer wall from yarns having greater impact resistance compared to the yarns forming the inner wall.

[0016] In another aspect of the invention, the method may further include forming the outer wall from at least one of polyester yarns, nylon yarns, polypropylene yarns, polyethylene yarns, acrylic yarns, cotton yarns, and rayon yarns.

[0017] In another aspect of the invention, the method may further include attaching an impact resistant layer to the exterior wall.

[0018] In another aspect of the invention, the method may further include stitching an impact resistant layer to the exterior wall.

[0019] In another aspect of the invention, the method may further include forming an inner wall from a refractory mineral yarn, such as from fiberglass, silica, basalt, ceramic, slate, slag, or the like, and forming an outer wall from a different yarn having increased impact resistance compared to the yarn forming the inner wall.

[0020] In another aspect of the invention, the method may further include knitting the interior wall with a 2x2 rib knit.

[0021] In other aspects of the invention, the method may further include knitting the exterior wall with other than a 2x2 rib knit.

[0022] In another aspect of the invention, the method may further include knitting the inner and outer walls together simultaneously on a flat bed knitting machine.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects, features and advantages of the present invention will be more readily understood when considered in conjunction with the following detailed description of the presently preferred embodiment and best mode, the appended claims and the accompanying drawings. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic isometric view of a knitted tubular sleeve constructed in accordance with one aspect of the present invention, shown assembled such that the elongated tubular member to be protected extends through a central cavity bounded by a circumferentially continuous inner wall of the sleeve. [Figure 1A] 1A is a schematic cross-sectional view taken generally along line 1A-1A of FIG. 1. [Figure 2A] 2 is a view of the sleeve of FIG. 1 shown in a first pre-assembled state, showing the radially inward facing inner surface of the wrappable outer wall; FIG. [Figure 2B] 2B is a view similar to FIG. 2A showing the outer surface of the wrappable outer wall facing radially outward. [Figure 3]FIG. 1 is a schematic isometric view of a knitted tubular sleeve shown in a partially assembled state, showing an elongated tubular member inserted through a central cavity in the circumferentially continuous inner wall of the sleeve, and showing the wrappable outer wall of the sleeve prior to being wrapped around the inner wall. DETAILED DESCRIPTION OF THE INVENTION

[0025] Detailed Description of the Present Preferred Embodiment 1 and 1A show a braided protective tubular sleeve, hereafter referred to as sleeve 10, constructed in accordance with one embodiment of the present disclosure shown, positioned around a protected content, shown as an insulated and protected elongated member 12. Sleeve 10 is protective, particularly in that it provides a thermal barrier against extreme heat, whether it is to prevent heat from radiating radially outward from elongated member 12 contained within sleeve 10, such as a high-temperature conduit or pipe in an engine compartment or exhaust pipe, or to provide a protective barrier for elongated member 12 contained within sleeve 10, such as a wire harness or cable, against heat radiating inward from nearby hot components, such as an engine or exhaust pipe. Sleeve 10 also provides protection against environmental contaminants ingressing and / or damaging sleeve 10 or contents 12 therein, for example, protection against impact forces such as from stone strikes, protection against abrasive debris or abrasive surfaces, and protection against liquid contaminants such as fuel, oil, and water. Sleeve 10 has a unitary, single-piece, tubular, braided wall 14 including a braided, circumferentially continuous inner wall 14' and a braided outer wall 14", where outer wall 14" is wrappable around circumferentially continuous inner wall 14' and where outer wall 14" is in a fixed relationship therearound such that outer wall 14" extends around the entire circumference of inner wall 14' to provide protection against impact forces, abrasion, contaminant ingress, and increased thermal insulation around the entire circumference of inner wall 14'. The inner and outer walls 14', 14" are knitted together as a single piece in a single knitting operation on a flat bed knitting machine, so that the final sleeve 10 can be easily handled as a single product and does not require a secondary sewing operation to join the inner and outer walls 14', 14" to one another.

[0026] Both the inner and outer walls 14', 14" provide thermal protection; however, an additional function of the outer wall 14" is to provide enhanced mechanical protection to the inner wall 14' and its contents 12 against wear and damage from debris, etc., which may impact, cut, and / or abrade the inner wall 14'. Thus, the outer wall 14″ prevents the aforementioned debris and abrasive forces from contacting the inner wall 14′. Meanwhile, the primary function of the inner wall 14′ is to provide thermal protection around the elongated member 12, such as by acting as a thermal barrier and / or heat sink to prevent heat from radiating outward from the elongated member 12 and radially outward from the inner wall 14′, particularly in exhaust pipe applications or other extreme heat applications, including pipes that act as conduits for high-temperature fluids, such as radiator pipes, hoses, etc. By preventing the inner wall 14′ from radiating heat outward, other vehicle systems and components are protected from exposure to the heat flowing through the exhaust pipe 12. However, because the outer wall 14″ is further protected from exposure to extreme heat shielded by the inner wall 14′, the yarns used to construct the outer wall 14″ may be provided from a different material than the inner wall 14′, such as yarns that are less resistant to heat but thereby have different properties, such as higher impact and / or abrasion resistance, if desired, than the yarns used to construct the inner wall 14′.

[0027] Additionally, as described in more detail below, a coating material, also referred to as coating layer 15, having impact, penetration and / or chemical resistance, and abrasion resistance properties may be secured to cover the radially outwardly facing surface of outer wall 14". Thus, the separate inner and outer walls 14', 14" in combination with coating layer 15 provide a synergistic effect, where each functions to benefit the other and provides a functional benefit to the contents 12 inside sleeve 10, thereby providing optimal performance attributes for sleeve 10.

[0028] The textile sleeve 10 is knitted, by way of example and not limitation, by a computerized flat bed knitting machine having opposing flat beds. The sleeve wall 14 is constructed on the computerized flat bed knitting machine, and the stitch types used to construct the inner and outer walls 14′, 14″ may be different, as desired for the intended application. Thus, the wall 14 may be knitted using several or combinations of stitch types, such as jersey, interlock, 2×2 rib forming stitches, or others, such that the inner and outer walls 14′, 14″ may be knitted using a single stitch or multiple stitch types, where the stitch types used to form the inner and outer walls 14′, 14″ may be the same or different from one another. Furthermore, the wall 14 may be constructed having any suitable length and diameter, as determined by the diameters provided by the inner and outer walls 14′, 14″. As will be apparent to those skilled in the art, the diameter of the tubular inner wall 14′ is controlled so that the outer wall 14″ is ultimately wrapped around the entire circumference of the tubular inner wall 14′.

[0029] The outer wall 14" is knitted as a generally flat piece of material, such as by needles from one of two knitting beds. The outer wall 14" has opposed edges 16,18 extending lengthwise between opposed ends 20,22. The outer wall 14" may be braided using any desired type of yarn material, whether monofilament and / or multifilament yarn, depending on the physical properties desired for the application. Considering that the inner wall 14' acts as the primary barrier to heat, thereby blocking heat from radiating radially outward toward the outer wall 14", the yarn used to braid the outer wall 14" may be less heat resistant than the yarn used to braid the inner wall 14". As such, yarns better suited to resist abrasion and impact forces from external debris may be used to construct the outer wall 14", resulting in a sleeve 10 that can resist both abrasion from external sources and impact forces from debris at the outer wall 14" without significant damage, while also functioning as an optimal barrier to radiant heat from the hot elongate member 12 at the inner wall 14'. Some yarns that may be suitable for braiding the outer wall 14" include polyester, nylon, polypropylene, polyethylene, acrylic, cotton, rayon, and fire retardant (FR) versions of all the aforementioned materials, as desired for the intended application.

[0030] The inner wall 14' is knitted as a circumferentially continuous tubular wall by both beds of a flat bed knitting machine, with one bed contributing to knitting mostly the upper or semicircular half (first side) of the inner wall 14' and the opposite bed contributing to knitting mostly the lower or semicircular half (second side) of the inner wall 14', the two portions being knitted together simultaneously in a seamless tubular form. During the knitting process, the inner wall 14' is integrally knit with the outer wall 14" as a single piece of material; here, this embodiment shown in FIGS. 1-3 and best described in FIGS. 2A-3 describes an inner wall 14' integrally knit with one opposing edge 16 of the outer wall 14", with an opposing edge 18 of the outer wall 14", also referred to as the free end, extending outwardly from and spaced apart from the inner wall 14'. The circumferentially continuous and seamless nature of the inner wall 14' allows the inner wall 14' to bound a central cavity 24 extending longitudinally along a central axis 26 (FIG. 1) between open ends 28, 30. The inner wall 14' is knit with one or more yarns that are heat-resistant, non-heat-settable multifilament and / or monofilament, suitable for withstanding harsh temperature environments ranging from approximately -60 to 1400 degrees Celsius (°C). The selected multifilament yarns may be formed of a mineral fiber material, such as, by way of example and without limitation, silica, fiberglass, ceramic, basalt, slate, slag, aramid, or carbon. The mineral fibers may be provided in a continuous or chopped fiber structure. In some extreme heat applications, it may be desirable to heat treat the mineral fiber sleeve material to remove organic content therefrom, thereby further increasing the heat resistance capacity of the sleeve 10. Because the high-temperature resistant yarns listed above are excellent at resisting extreme heat but may generally be damaged if subjected to direct contact with abrasion and / or impact forces, the outer wall 14″ is constructed and provided to significantly improve the inner wall 14′'s resistance to damage from abrasion and impact forces, and to significantly increase the overall durability of the final sleeve 10.

[0031] In addition to the materials described above, it is contemplated that, if desired, the same mineral fiber yarns used to construct the inner wall 14′, or different mineral fiber yarns, may be used to construct the outer wall 14″, with the coating layer 15 then being applied to the outer wall 14″ after it has been braided. By applying a coating layer 15, such as, by way of example and without limitation, a silicone or Teflon layer, to the outer wall 14″, the outer wall 14″ provides improved protection against heat radiating outward from the sleeve 10 or radially inward of the sleeve 10, while simultaneously becoming impervious to fluids and more abrasion and impact resistant. The coating layer 15 may be applied to the outer surface 34 of the outer wall 14″ by any suitable fastening mechanism, including, by way of example and without limitation, a high temperature resistant adhesive and / or a mechanical fastening mechanism, such as stitches 32. The stitching 32 is shown extending along and adjacent the outer periphery of the outer wall 14", with the outer peripheral region 38 of the coating layer 15 wrapped around the outer periphery of the outer wall 14" such that the outer periphery of the outer wall 14" is sandwiched between the radially outwardly facing outermost surface 40 of the coating layer 15 and the wrapped outer peripheral region 38 of the coating layer 15. The stitching 32 is provided by a strong, tough, high temperature resistant filament, such as, by way of example and without limitation, a fiberglass yarn having a PTFE coating or a metal yarn.

[0032] One or more fasteners may be secured to the outer wall 14" to facilitate maintaining the outer wall 14" in a wrapped configuration around the cylindrical inner wall 14'. In the exemplary embodiment shown, a plurality of fasteners, such as, by way of example and without limitation, snaps 36, may be secured to the outer wall 14" to secure the outer wall 14" to one another while the outer wall 14" is wrapped around the inner wall 14'. It should be appreciated that other types of fastening mechanisms, such as, by way of example and without limitation, hook and loop, may be used. The snaps 36 are arranged with a plurality of female snap portions 36a secured adjacent the free edge 18 and a corresponding plurality of male snap portions 36b secured adjacent the opposing edge 16 of the outer wall 14". It should be appreciated that an inverse relationship between any one or all of the female and male snap portions 36a, 36b is contemplated herein. Thus, by placing the elongate member 12 through the central cavity 24 of the inner wall 14' (FIG. 3), the outer wall 14" can be easily wrapped around the inner wall 14' such that the corresponding male and female snap portions 36a, 36b snap together to provide a releasably secured attachment that maintains the outer wall 14" in its wrapped configuration.

[0033] Numerous modifications and variations of the present invention are possible, as will be readily apparent to those skilled in the art in light of the above teachings. It is contemplated that all claims and features of all embodiments may be combined with each other, provided such combinations are not mutually inconsistent. It is therefore to be understood that the present invention may be practiced other than as specifically described, and that the scope of the present invention is defined by the number of claims ultimately allowed.

Claims

1. A wrappable sleeve for providing EMI protection around an elongated member, comprising: an outer wall of crossed wires having opposed outer edges extending longitudinally between opposed outer ends; a wrappable sleeve comprising: an inner wall of crossed threads secured to the outer wall, the inner wall having opposed inner edges extending longitudinally between opposed inner ends, the threads including heat-set threads urging the inner and outer edges into an overlapping relationship, at least some of the threads having exposed conductive material bonded thereto.

2. The braided sleeve of claim 1 , wherein the yarns forming the outer braided wall have greater impact resistance than the yarns forming the inner braided wall.

3. 3. The braided sleeve of claim 2, wherein the yarns forming the outer braided wall are made of at least one of polyester, nylon, polypropylene, polyethylene, acrylic, cotton, and rayon.

4. 4. The knitted sleeve of claim 3, wherein the yarns forming the circumferentially continuous tubular inner knitted wall are multifilament mineral fibers.

5. 5. The braided sleeve of claim 4, wherein the yarns forming the circumferentially continuous tubular braided inner wall are comprised of at least one of silica, fiberglass, ceramic, basalt, slate, slag, aramid, and carbon.

6. The braided sleeve of claim 1 further comprising an impact resistant layer covering the outer wall.

7. The braided sleeve of claim 6 , wherein the impact resistant layer forms a circumferentially continuous layer around the inner wall when the outer wall is wrapped around the inner wall.

8. 8. The knitted sleeve of claim 7, further comprising a plurality of fasteners secured to the impact resistant layer, pairs of the plurality of fasteners being capable of being secured to one another to maintain the outer wall in a wrapped relationship about the inner wall.

9. The braided sleeve of claim 6 , wherein the impact resistant layer is sewn to the outer wall.

10. The knitted sleeve of claim 1 , wherein the inner wall is knitted with a 2×2 rib knit.

11. 1. A method of constructing a tubular textile sleeve for providing a thermal barrier around an elongate member extending through the tubular textile sleeve, comprising: braiding a circumferentially continuous tubular inner wall having a central cavity extending longitudinally along a central axis between opposed open ends; 1. A method of constructing a tubular textile sleeve, comprising knitting an outer wall having opposed edges extending longitudinally between opposed ends integral with the inner wall such that the outer wall extends away from the inner wall, the outer wall being wrappable around the inner wall to form the sleeve having a double layer wall.

12. The method of claim 11 , further comprising securing an impact resistant layer to a radially outward facing outer surface of the outer wall.

13. The method of claim 12 further comprising stitching the impact resistant layer to the exterior wall.

14. 13. The method of claim 12, further comprising securing at least one fastener to the impact resistant layer and configuring the at least one fastener to releasably maintain the outer wall in wrappable relationship about the inner wall.

15. 15. The method of claim 14, further comprising securing a plurality of said at least one fastener to said impact resistant layer, and providing each of said plurality of fasteners including a female snap portion and a male snap portion configured to snap together in a releasably secured attachment such that said outer wall is maintained in its wrapped configuration.

16. 12. The method of claim 11, further comprising forming the outer wall from yarns having greater impact resistance compared to the yarns forming the inner wall.

17. 17. The method of claim 16, further comprising forming the outer wall from at least one of polyester yarns, nylon yarns, polypropylene yarns, polyethylene yarns, acrylic yarns, cotton yarns, and rayon yarns.

18. 12. The method of claim 11, further comprising forming the inner wall from a heat-resistant mineral yarn, such as from fiberglass, silica, basalt, ceramic, slate, slag, or the like, and forming the outer wall from a different yarn having increased impact resistance compared to the yarn forming the inner wall.

19. The method of claim 11 further comprising knitting the interior wall with a 2x2 rib knit.

20. 20. The method of claim 18, further comprising knitting the exterior wall other than a 2x2 rib knit.

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