CIRCUMFERENTIALLY CONTINUOUS, FIRE SUPPRESSING, DIELECTRIC SLEEVE

Abstract

A sleeve for protecting an elongate member, including a bus-bar of a battery pack, and method of construction thereof are provided. The sleeve includes a knit wall having a circumferentially continuous outer surface extending along a longitudinal axis between opposite open ends. The knit wall is formed at least in part by multifilament flame-resistant yarn. The multifilament flame-resistant yarn is knit to form both the knit wall, and also first ribs extending lengthwise along the circumferentially continuous outer surface or second ribs extending annularly about said circumferentially continuous outer surface. An impervious, flame-resistant coating is bonded to an outer surface of the circumferentially continuous knit wall.

Claims

1. A sleeve for protecting an elongate member, comprising: a knit wall having a circumferentially continuous outer surface extending along a longitudinal axis between opposite open ends, said knit wall being formed at least in part by multifilament flame-resistant yarn, wherein said multifilament flame-resistant yarn is knit to form first ribs extending lengthwise along said circumferentially continuous outer surface or second ribs extending annularly about said circumferentially continuous outer surface.

2. The sleeve of claim 1, further including an impervious coating extending about said circumferentially continuous outer surface of said knit wall.

3. The sleeve of claim 2, wherein said impervious coating is one of a silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane layer bonded directly to said circumferentially continuous outer surface of said knit wall.

4. The sleeve of claim 1, wherein said plurality of first ribs and said second ribs are formed via alternating knit and purl stitches with one another in a desired pattern.

5. The sleeve of claim 2, wherein said multifilament flame-resistant yarn is a mineral yarn.

6. The sleeve of claim 5, wherein said mineral yarn is at least one of fiberglass, silica, and basalt.

7. The sleeve of claim 5, wherein said knit wall is formed entirely of said mineral yarn.

8. The sleeve of claim 1, wherein said knit wall is configured to be disposed about a bus-bar of a battery pack of an electric vehicle.

9. A sleeve for protecting a bus-bar connection between battery packs of an electric vehicle, consisting of: a knit wall having a circumferentially continuous outer surface extending along a longitudinal axis between opposite open ends, said knit wall being formed at least in part by multifilament flame-resistant yarn, wherein said multifilament flame-resistant yarn is knit to form one of first ribs R extending lengthwise in generally parallel relation with said longitudinal axis or second ribs R extending circumferentially about said longitudinal axis; and an impervious coating extending about said outer surface of said knit wall.

10. The sleeve of claim 9, wherein said impervious coating is one of a silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane layer bonded directly to said circumferentially continuous outer surface of said knit wall.

11. The sleeve of claim 9, wherein said plurality of first ribs and said second ribs are formed via alternating knit and purl stitches with one another in a desired pattern.

12. The sleeve of claim 9, wherein said multifilament flame-resistant yarn is a mineral yarn.

13. The sleeve of claim 12, wherein said mineral yarn is at least one of fiberglass, silica, and basalt.

14. The sleeve of claim 12, wherein said knit wall is formed entirely of said mineral yarn.

15. A method of constructing a sleeve for providing dielectric protection to a bus-bar interconnecting portions of an electric vehicle battery pack to one another, comprising: knitting multifilament flame-resistant yarn to form a knit wall having a circumferentially continuous outer surface extending along a longitudinal axis between opposite open ends; and forming a plurality of first ribs extending lengthwise in generally parallel relation with the longitudinal axis in the knit wall or a plurality of second ribs extending circumferentially about the longitudinal axis in the knit wall.

16. The method of claim 15, further including bonding an impervious coating to the circumferentially continuous outer surface of the knit wall.

17. The method of claim 16, further including forming the impervious coating from one of a silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane material.

18. The method of claim 16, further including forming the first ribs and the second ribs by alternating knit and purl stitches with one another.

19. The method of claim 16, further including providing the multifilament flame-resistant yarn as a mineral yarn and knitting the entirety of the knit wall from the mineral yarn.

20. The method of claim 15, further including knitting the first ribs in substantially equidistantly spaced relation from one another or knitting the second ribs in substantially equidistantly spaced relation from one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] These and other aspects, features and advantages will become readily apparent to those skilled in the art in view of the following detailed description of presently preferred embodiments and best mode, appended claims, and accompanying drawings, in which:

[0046] FIG. 1 is a perspective view of a motor vehicle having a knit sleeve constructed in accordance with one aspect of the disclosure shown disposed about an electric vehicle battery member to be protected;

[0047] FIG. 2 is an enlarged, fragmentary schematic perspective view of the knit sleeve in accordance with one aspect of the disclosure shown disposed about the elongate member to be protected with the textile sleeve;

[0048] FIG. 2A is an enlarged, fragmentary schematic perspective view of the knit sleeve in accordance with another aspect of the disclosure shown disposed about the elongate member to be protected with the textile sleeve;

[0049] FIG. 3 is an enlarged schematic cross-sectional view taken generally along the line 3-3 of FIG. 2;

[0050] FIG. 4A is a view perspective view of the knit sleeve prior to being coated, with the knit sleeve shown disposed about the bus-bar;

[0051] FIG. 4B is a view similar to FIG. 4A illustrating an impervious coating coated on an outer surface of the knit wall of FIG. 4A;

[0052] FIG. 5 is an enlarged, fragmentary schematic perspective view of a textile sleeve constructed in accordance with another aspect of the disclosure shown disposed about the elongate member to be protected with the textile sleeve shown in an as manufactured, non-shrunken state;

[0053] FIG. 5A is a view similar to FIG. 5 with the textile sleeve shown in a shrunken state;

[0054] FIG. 6 is an enlarged schematic cross-sectional view taken generally along the line 6-6 of FIG. 5;

[0055] FIG. 6A is an enlarged schematic cross-sectional view taken generally along the line 6A-6A of FIG. 5A;

[0056] FIG. 7A is a schematic plan view of a textile layer of the sleeve illustrating the innermost textile layer being woven in accordance with one embodiment of the disclosure;

[0057] FIG. 7B is a view similar to FIG. 7A illustrating a textile layer being braided in accordance with another embodiment of the disclosure; and

[0058] FIG. 7C is a view similar to FIG. 7A illustrating a textile layer being knitted in accordance with yet another embodiment of the disclosure;

[0059] FIG. 8 is an enlarged, fragmentary schematic perspective view of a textile sleeve constructed in accordance with another aspect of the disclosure shown disposed about the elongate member to be protected with the textile sleeve shown in an as manufactured, non-shrunken state;

[0060] FIG. 9 is a view similar to FIG. 8 with the textile sleeve shown in a shrunken state;

[0061] FIG. 10 is an enlarged schematic cross-sectional view taken generally along the line 10-10 of FIG. 8;

[0062] FIG. 10A is an enlarged schematic cross-sectional view taken generally along the line 10A-10A of FIG. 9;

[0063] FIG. 11A is a schematic plan view of a textile layer of the sleeve illustrating the innermost textile layer being woven in accordance with one embodiment of the disclosure;

[0064] FIG. 11B is a view similar to FIG. 11A illustrating a textile layer being braided in accordance with another embodiment of the disclosure; and

[0065] FIG. 11C is a view similar to FIG. 11A illustrating a textile layer being knitted in accordance with yet another embodiment of the disclosure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0066] Referring in more detail to the drawings, FIG. 1 illustrates a protective textile sleeve, referred to hereafter as sleeve 10, constructed in accordance with one aspect of the invention having a textile knit wall 12 disposed about an elongate member 11 to be protected, such as a bus-bar interconnecting portions, such as adjacent cells and/or cell modules of a battery pack, referred to hereafter as battery B, of a vehicle, such as an electric vehicle EV, to one another. The knit wall 12 has a seamless, circumferentially continuous outer surface 13 that extends lengthwise between open opposite ends 14, 16 and about a longitudinal central axis 18 to bound a central cavity 20. The elongate member 11 extends through and is protected in the central cavity 20 against impact forces by the knit wall 12, such as may be experienced in a vehicle crash, abrasion, and ingress of contamination, by way of example and without limitation. The knit wall 12 suppresses flame propagation, such as in the event of thermal runaway of one or more of the cells of the battery B, thereby allowing the electric vehicle EV to remain powered by the battery for 5 minutes or more to allow the electric vehicle EV to be safely driven to a parked location, whereat the operator can evacuate the electric vehicle EV. The knit wall 12 is formed at least in part or entirely of flame-resistant multifilament yarn 22 knit in a rib-stitch pattern to enhance elasticity and stretchability of the wall 12 to facilitate assembly of the sleeve 10 about the elongate member 11. A plurality of ribs (R) are formed via alternating knit and purl stitches with one another in a desired pattern, such as 1×1; 2×2, by way of example and without limitation, to form lengthwise extending (warp direction) first ribs R (FIG. 2) or circumferentially extending (weft or fill) second ribs R (FIG. 2A) to facilitating the formation of a wrinkle-free, snug conforming fit of the knit wall 12 about the bus-bar 11, thereby facilitating assembly and the suppression of flame, having a non-bulky low profile, and being aesthetically appealing. Accordingly, the knit structure of the knit wall 12 is stretchable axially and radially (circumferentially), thereby allowing the knit wall 12 to flex and be easily assembled into close, snug fitting relation about the bus-bar 11.

[0067] To further enhance the flame resistance, stretchability and resilience of the sleeve 10, an impervious coating 26 is provided to extend about the outer surface 13 of the knit wall 12 to prevent the ingress and penetration of dust, particles, smoke through the knit wall 12, and to enhance the flame resistance and flame protection of the sleeve 10. The impervious coating 26 is elastically stretchable in all directions, including the lengthwise and radial directions, to allow the underlying knit wall 12 to remain stretchable along the lengthwise and radial directions, and is elastically resilient, thereby facilitating the formation of a wrinkle-free, snug conforming fit of the knit wall 12, and ultimately the sleeve 10, about the bus-bar 11.

[0068] Upon being exposed to an extreme heat scenario, such as during an unintended thermal runaway condition within the battery, the flame-resistant multifilament yarn 22 retain their structural integrity to suppress flame growth and propagation for at least 5 minutes or more, thereby allowing ample time for an occupant of the motor vehicle EV to park and/or evacuate the motor vehicle EV.

[0069] The impervious coating 26, such as a silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane coating, can be applied and bonded to the outer surface 13, with the coating 28 also referred to as layer, being bonded directly to the outer surface 13. The impervious layer 26 can be applied to the outer surface 13 using any desired process that allows the desired thickness (t) of the layer 26 to be attained. In the exemplary embodiment, the thickness t is between about 0.05 and 3 mm, and more preferably between about 0.1 and 0.3 mm. When the layer 26 is provided within the aforementioned range of thickness t, flexibility and conformability of the wall 12 is optimized, and optimal dielectric strength is provided, which can provide a dielectric breakdown voltage between about 5 to 40 kV. Accordingly, the elongate member 11 is protected against unwanted electrical interference, including electromagnetic interference (EMI), radiofrequency interference (RFI), and electrostatic discharge (ESD). In addition to the various electrical protections, greatly enhanced protection to the elongate member 11 against impact forces can be provided by the layer 26. Further yet, enhanced protection against the ingress of contamination is provided, such as to fluid gas and solid debris, given the layer 26 can be hydrophobic and impervious to fluid and debris.

[0070] In accordance with another aspect, a method of constructing a thermally protective sleeve 10 is provided. The method includes knitting multifilament flame-resistant yarn to form a textile wall 12 having a circumferentially continuous outer surface 13 extending along a longitudinal axis 18 between opposite open ends 14, 16. The method can further includes knitting the multifilament flame-resistant yarn using a rib-stitch pattern to form first ribs R extending lengthwise along a longitudinal axis 18 of the sleeve 10 (FIG. 2), or second ribs R extending circumferentially in annular fashion about the longitudinal axis 18 of the sleeve 10 (FIG. 2A), wherein the ribs R enhance the flame resistance of the wall 12, while at the same time enhancing the stretchability of the wall 12 in both the radial and axial directions.

[0071] In accordance with another aspect of the invention, the method can further include bonding an impervious coating 26 to the outer surface 13 of the textile wall 12, wherein the impervious coating 26 is formed of an elastomeric material to enhance the stretchability and resilience of the sleeve 10.

[0072] In accordance with another aspect of the invention, the method can further include forming the impervious coating 26 with an elastomeric, stretchable silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane material.

[0073] FIGS. 5-7B illustrate a textile sleeve, referred to hereafter as sleeve 110, constructed in accordance with one aspect of the invention having a textile wall 112 disposed about an elongate member 111 to be protected, such as a bus-bar interconnecting batteries B of a vehicle, such as an electric vehicle EV, to one another. The textile wall 112 has a seamless, circumferentially continuous outer surface 113 that extends lengthwise between open opposite ends 114, 116 and about a longitudinal central axis 118 to bound a central cavity 120, through which the elongate member 111 extends and in which the elongate member 111 is protected against impact forces, such as may be experienced in a vehicle crash, abrasion, and ingress of contamination, by way of example and without limitation. The wall 112 suppresses flame propagation, such as in the event of thermal runaway of one or more of the batteries, thereby allowing the electric vehicle to remain powered by the batteries B for 5 minutes or more to allow the electric vehicle to be safely driven to a parking location, whereat the operator can evacuate the electric vehicle. The textile wall 112 is formed of flame-resistant multifilament yarn 122 interlaced with shrinkable yarn 124, wherein the shrinkable yarn 124 is configured to constrict the continuous outer surface 113 from a first diameter D1 (FIG. 6) to a reduced second diameter D2 (FIG. 6A) into close fitting, conforming relation about the contour of the elongate member 111, thereby facilitating the suppression of flame, having a non-bulky low profile, and being aesthetically appealing. It is to be understood that the constriction of the sleeve 110 from the first diameter D1 to the second D2 may cause the sleeve 111 to take on a shape other than being circular, and may constrict about any underlying contour shape, such as rectangular (FIG. 6A), by way of example and without limitation, to conform into a close, snug fit about the generally rectangular cross-sectional shape of a known bus-bar 111. As such, the shrinkage of the sleeve 110 can conform to non-circular contours, such shown by constricting across a major diameter D2 and a minor diameter D2′ of the bus-bar 111 illustrated in FIGS. 6 and 6A. This is especially useful when constricting about electrical connectors and the like, such as about terminals T of the vehicle battery B, by way of example and without limitation.

[0074] The textile wall 112 is one of a woven wall (FIG. 7A), braided wall (FIG. 7B) or knit wall (FIG. 7C) constructed in circumferentially continuous, tubular fashion. It will be appreciated by one possessing ordinary skill in the art that a minimum amount of shrinkable yarn 124 can be used that is sufficient to bring the wall 112 from its enlarged assembly state (FIGS. 5 and 6) to its final assembled shrunken state (FIG. 5A and 6A). Upon being exposed to an extreme heat scenario, such as during an unintended thermal runaway condition of one or more of the cells of the battery(ies) B, the shrinkable yarn 124 can be burned away or significantly burned by the excessive heat, while the flame-resistant multifilament yarn 122 retain their structural integrity to suppress flame growth and propagation for at least 5 minutes or more, thereby allowing ample time for an occupant of the motor vehicle EV to park and/or evacuate the motor vehicle EV.

[0075] An impervious coating 126 can be applied and bonded to the outer surface 113, such as a silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane coating, also referred to as layer, bonded directly to the outer surface 113. The impervious layer 126 can be applied to the outer surface 113 using any desired process that allows the preferred thickness (t) of the layer 126 to be attained. In the exemplary embodiment, the thickness t is between about 0.05 and 3 mm, and more preferably between about 0.1 and 0.3 mm. When the layer 126 is provided within the aforementioned range of thickness t, flexibility and conformability of the wall 112 remains and optimal dielectric strength is provided, which can provide a dielectric breakdown voltage between about 5 to 40 kV. Accordingly, the elongate member 111 is protected against unwanted electrical interference, including electromagnetic interference (EMI), radiofrequency interference (RFI), and electrostatic discharge (ESD). In addition to the various electrical protections, greatly enhanced protection to the elongate member 111 against impact forces can be provided by the layer 126. Further yet, enhanced protection against the ingress of contamination is provided, such as fluid and debris, given the layer 126 can be hydrophobic and impervious to fluid and debris.

[0076] In accordance with another aspect, a method of constructing a sleeve 110 is provided. The method includes interlacing multifilament flame-resistant yarn to form a textile wall 112 having a circumferentially continuous outer surface 113 extending along a longitudinal axis 118 between opposite open ends 114, 116 and, interlacing the multifilament flame-resistant yarn 122 with shrinkable yarn 124, wherein the shrinkable yarn 124 is configured to constrict the circumferentially continuous outer surface 113 from a first diameter D1 to a reduced second diameter D2, D2′ (including non-circular shapes, as discussed above) into close fitting, conforming relation with the bus-bar 111.

[0077] In accordance with another aspect of the invention, the method can further include bonding an impervious coating 126 to the outer surface 113 of the textile wall 112.

[0078] In accordance with another aspect of the invention, the method can further include weaving the multifilament flame-resistant yarn 122 and the shrinkable yarn 124 to form the textile wall.

[0079] In accordance with another aspect of the invention, the method can further include braiding the multifilament flame-resistant yarn 122 and the shrinkable yarn 124 to form the textile wall 112.

[0080] In accordance with another aspect of the invention, the method can further include knitting the multifilament flame-resistant yarn 122 and the shrinkable yarn 124 to form the textile wall 112.

[0081] FIG. 8 illustrates a textile sleeve, referred to hereafter as sleeve 210, constructed in accordance with another aspect of the invention having a textile wall 212 disposed about an elongate member 211 to be protected, such as a bus-bar interconnecting cells of an electric battery B of a vehicle, such as an electric vehicle EV, to one another. The textile wall 212 has a seamless, circumferentially continuous outer surface 213 that extends lengthwise between open opposite ends 214, 216 and about a longitudinal central axis 218 to bound a central cavity 220. The elongate member 211 extends through and is protected in the central cavity 220 against impact forces by the wall 212, such as may be experienced in a vehicle crash, abrasion, and ingress of contamination, by way of example and without limitation. The wall 12 suppresses flame propagation, such as in the event of thermal runaway of one or more of the cells of the battery(ies), thereby allowing the electric vehicle to remain powered by the batteries for 5 minutes or more to allow the electric vehicle to be safely driven to a parking location, whereat the operator can evacuate the electric vehicle. The textile wall 212 is formed of flame-resistant multifilament yarn 222 interlaced with shrinkable yarn 224, including monofilaments or multifilaments, wherein the shrinkable yarn 224 is configured to shrink and constrict circumferentially extending discrete regions 225 spaced axially from one another along the longitudinal axis 218, from a non-shrunken state (FIG. 10), to form the seamless, continuous outer surface 213 having a convolute contour formed by a plurality of peaks P and a plurality of valleys V alternating with one another, to a shrunken state (FIGS. 9 and 10A). The shrunken discrete regions 225 thereby bring the wall 213 into close fitting, conforming relation about the contour of the elongate member 211, thus, facilitating the suppression of flame, having a non-bulky low profile, and being aesthetically appealing. It is to be understood that the constriction of the sleeve 210 can be about any geometric shape, including circular and noncircular bus-bars 211, as viewed in lateral cross-section. As such, the shrinkage of the sleeve 210 can conform to non-circular contours, such shown by constricting across a major diameter D2 and a minor diameter D2′ of the bus-bar 211 illustrated in FIGS. 9 and 10A. This is especially useful when constricting about irregularly shaped electrical connectors and the like, by way of example and without limitation. It is to be further understood that the convolute contour provided by the peaks P and valleys V enhance flexibility of the sleeve 210, thereby allowing the sleeve 210 to be routed over serpentine, meandering paths without kinking, while also enhancing the impact resistance via the peaks P.

[0082] The textile wall 212 is one of a woven wall (FIG. 11A), braided wall (FIG. 11B) or knit wall (FIG. 11C) constructed in circumferentially continuous, tubular fashion. It will be appreciated by one possessing ordinary skill in the art that a minimum amount of shrinkable yarn 224 can be used that is sufficient to form the desire number and width of valleys V along the wall 212. It is to be recognized that the individual widths of the valleys V can be provided as desired, wherein the widths can be the same or different from one another, as desired, by providing the discrete regions 225 with the same number of circumferentially extending shrinkable yarns 224 to provide the valleys V having the same widths relative to one another, or different numbers of circumferentially extending shrinkable yarns 224, as desired, to provide at least some of the discrete regions 225, and valleys V resulting therefrom, having varying, different widths relative to one another. Upon being exposed to an extreme heat scenario, such as during an unintended thermal runaway condition of one or more cells of the battery(ies), the shrinkable yarn 224 can be burned away or significantly burned by the excessive heat, while the flame-resistant multifilament yarn 222 retain their structural integrity to suppress flame growth and propagation for at least 5 minutes or more, thereby allowing ample time for an occupant of the motor vehicle EV to park and/or evacuate the motor vehicle EV.

[0083] An impervious, intumescent coating, also referred to as solid layer or layer 226, can be applied and bonded to the outer surface 213, such as a silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane coating, also referred to as layer, bonded directly to the outer surface 213. The impervious layer 226 can be applied to the outer surface 213 using any desired process that allows the preferred thickness (t)(FIG. 10) of the layer 226 to be attained. In the exemplary embodiment, the thickness t is between about 0.05 and 3 mm, and more preferably between about 0.1 and 0.3 mm. When the layer 226 is provided within the aforementioned range of thickness t, flexibility and conformability of the wall 212 remains and optimal dielectric strength is provided, which can provide a dielectric breakdown voltage between about 5 to 40 kV. Accordingly, the elongate member 211 is protected against unwanted electrical interference, including electromagnetic interference (EMI), radiofrequency interference (RFI), and electrostatic discharge (ESD). In addition to the various electrical protections, greatly enhanced protection to the elongate member 211 against impact forces can be provided by the layer 226. Further yet, enhanced protection against the ingress of contamination is provided, such as fluid and debris, given the layer 226 can be hydrophobic and impervious to fluid and debris.

[0084] In accordance with another aspect, a method of constructing a sleeve 210 is provided. The method includes interlacing multifilament flame-resistant yarn 222 to form a textile wall 212 having a seamless, circumferentially continuous outer surface 213 extending along a longitudinal axis 218 between opposite open ends 214, 216 and, interlacing the multifilament flame-resistant yarn 222 with selectively located shrinkable yarn 224, wherein the shrinkable yarn 224 is configured to shrink and constrict circumferentially extending, annular discrete regions 225 of the textile wall 12, spaced axially from one another along the longitudinal axis 218, to form the continuous outer surface 213 with a convolute contour formed by a plurality of peaks P and a plurality of valleys V alternating with one another. The peaks P are formed predominately or entirely of the multifilament flame-resistant yarn 222, while the valleys V are formed predominately or entirely of the shrinkable yarn 224 in the weft direction, with multifilament flame-resistant yarn 222 extending therethrough in the warp direction. Accordingly, the weft direction yarns forming the valleys V can be provided entirely of the shrinkable yarn 224.

[0085] In accordance with another aspect of the invention, the method can further include bonding an impervious coating 226 to the outer surface 213 of the textile wall 212.

[0086] In accordance with another aspect of the invention, the method can further include weaving the multifilament flame-resistant yarn 222 and the shrinkable yarn 224 to form the textile wall 212.

[0087] In accordance with another aspect of the invention, the method can further include braiding the multifilament flame-resistant yarn 222 and the shrinkable yarn 224 to form the textile wall 212.

[0088] In accordance with another aspect of the invention, the method can further include knitting the multifilament flame-resistant yarn 222 and the shrinkable yarn 224 to form the textile wall 212.

[0089] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is contemplated that all features of all claims and of all embodiments can be combined with each other, so long as such combinations would not contradict one another. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.