Self-curling non-woven sleeve and method of construction thereof

A self-wrapping nonwoven sleeve for routing and protecting elongate members and method of construction thereof is provided. The sleeve includes a non-woven wall having a thickness extending between inner and outer sides. The wall has opposite edges extending along a length of the sleeve between opposite ends. The opposite edges are biased into a self-wrapped configuration by heat-set material of the nonwoven wall to define a tubular cavity. The non-woven wall includes first and second portions extending between the opposite edges. The first portion and second portion have respective first and second thicknesses extending between the inner and outer sides, wherein the first thickness is greater than the second thickness and wherein the first portion provides flexibility to the wall and the second portion is heat set to bias the wall into its self-wrapped configuration.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates generally to protective non-woven sleeves which can be fitted about elongated items such as wires, wire harnesses, pipes, hoses tubing and the like to protect such elongated items from heat, cuts, chafing, abrasion and/or to provide shielding from vibration, noise and/or harshness.

2. Related Art

U.S. Pat. Nos. 7,523,532 and 7,754,301 disclose a non-woven sleeve for use in covering elongated items, such as wires, wire harnesses, pipes, hoses tubing and the like. Such a non-woven sleeve is taught as being uniformly compressed to a desired density (which can vary depending upon the application) and also biased to a self-curling shape, so that when the sleeve is forced open along its slit edge and positioned about the elongated item, releasing the sleeve causes it to self-curl and wrap about the elongated item. Such a sleeve has the advantage of being self-wrapping and being made of non-woven material, but also has its limitations in that the densified self-curling attribute has the effect of making the product rather stiff and resistant to flexing, which can present a challenge when the sleeve is to be used to cover an elongated item that has curvature (e.g., a curved wire harness).

SUMMARY OF THE INVENTION

A self-wrapping nonwoven sleeve for routing and protecting elongate members is provided. The sleeve includes an elongate non-woven wall having inner and outer sides with a thickness of the wall extending between the inner and outer sides. The wall has opposite edges extending along a longitudinal axis of the sleeve between opposite ends of the sleeve. The opposite edges are biased into a self-wrapped configuration about the longitudinal axis to define a tubular cavity. The opposite edges are extendable away from one another under an externally applied force to expose the cavity for insertion or removal of the elongate members and return to their self-wrapped configuration upon removal of the externally applied force. The non-woven wall includes at least one circumferentially extending first band portion extending between the opposite edges and at least one circumferentially extending second band portion extending between the opposite edges. The at least one first band portion has a first thickness and first density extending between the inner and outer sides and the at least one second band portion has a second thickness and second density extending between the inner and outer sides. The first thickness is greater than the second thickness and the first density is less than the second density.

In accordance with another aspect of the invention, the non-woven wall includes a plurality of the first band portions and a plurality of the second band portions.

In accordance with another aspect of the invention, the at least one second band portion includes heat-set material that exerts a self-curling bias force to bias the opposite edges into their self-wrapped configuration to define the tubular cavity.

In accordance with another aspect of the invention, the at least one first band portion imparts increased flexibility to the sleeve relative to the at least one second band portion as a result of the at least one first band portion not including heat-set material.

In accordance with another aspect of the invention, the inner side is smooth and the outer side includes undulations of circumferentially extending peaks and troughs.

In accordance with another aspect of the invention, a foil layer is bonded to at least one of the inner side and the outer side.

In accordance with another aspect of the invention, the foil layer is bonded to the inner side.

In accordance with another aspect of the invention, the foil layer is bonded to the outer side.

In accordance with another aspect of the invention, the foil layer is bonded to the inner side and the outer side.

In accordance with another aspect of the invention, a self-wrapping nonwoven sleeve for routing and protecting elongate members is provided including an elongate non-woven wall having inner and outer sides with a thickness of the wall extending across the inner and outer sides. The wall has opposite edges extending along a longitudinal axis of the sleeve between opposite ends of the sleeve. The edges are biased into a self-wrapped configuration about the longitudinal axis to define a tubular cavity. The edges are extendable away from one another under an externally applied force to expose the cavity for insertion or removal of the elongate members and return to their self-wrapped configuration upon removal of the externally applied force. The non-woven wall includes a plurality of first portions isolated from one another by at least one second portion. The plurality of first portions have a first thickness extending between the inner and outer sides and a first density and the at least one second portion has a second thickness extending between the inner and outer sides and a second density. The first thickness is greater than the second thickness and the first density is less than the second density.

In accordance with another aspect of the invention, a method of constructing a self-wrapping sleeve used to route and protect elongate members is provided. The method includes forming an elongate non-woven wall having a thickness extending between opposite inner and outer sides and having opposite edges extending between opposite ends of the wall. Further, heat-setting the non-woven wall into a self-wrapped configuration to define a tubular cavity. In addition, forming at least one circumferentially extending first band portion having a first density and first thickness extending between the opposite edges and forming at least one circumferentially extending second band portion having a second density that is greater than the first density of the at least one first band portion and having a second thickness extending between the opposite edges, wherein the second thickness of the at least one second band portion is less than the first thickness of the at least one first band portion.

In accordance with another aspect of the invention, the method further includes forming a plurality of the first band portions and a plurality of the second band portions in the nonwoven wall.

In accordance with another aspect of the invention, the method further includes heat-setting material in the at least one second band portion during the heat-setting step so that the at least one second band portion exerts a bias force to bias the edges into the self-wrapped configuration.

In accordance with another aspect of the invention, the method further includes avoiding heat-setting the at least one first band portion so that the at least one first band portion has an increased flexibility relative to the at least one second band portion.

In accordance with another aspect of the invention, the method further includes forming the inner side having a smooth surface and forming the outer side having undulations of circumferentially extending peaks and troughs.

In accordance with another aspect of the invention, the method further includes bonding a foil layer to at least one of the inner and outer sides.

In accordance with another aspect of the invention, a method of constructing a self-wrapping sleeve used to route and protect elongate members includes forming an elongate non-woven wall having a thickness extending between opposite inner and outer sides and having opposite edges extending between opposite ends of the wall. Further, heat-setting the non-woven wall into a self-wrapped configuration to define a tubular cavity and forming at least one circumferentially extending first band portion having a first density and first thickness extending between the opposite edges. Further, forming a plurality of first portions isolated from one another by at least one second portion, with the plurality of first portions having a first thickness extending between the inner and outer sides and having a first density and with the at least one second portion having a second thickness extending between the inner and outer sides and having a second density, wherein the first thickness is greater than the second thickness and the first density is less than the second density.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS

Referring in more detail to the drawings,FIGS. 1-4illustrate a sleeve10constructed in accordance with one aspect of the invention that is self-wrapping as a result of being heat-set in construction. The sleeve10has a wall12that is initially constructed as a substantially flat non-woven material that is subsequently heat-formed into a biased, self-wrapping tubular configuration to form the tubular sleeve10. With the wall12being heat-set to take on its curled configuration, a split, also referred to as seam or split seam14, extends along the length of the sleeve10, wherein the wall12provides a circumferentially enclosed inner cavity16when in its relaxed, self-wrapped configuration. The cavity16is generally tubular and readily accessible along a central longitudinal axis17of the sleeve10so that elongate members M, such as wires or a wire harness, for example, can be readily disposed radially toward the axis17into the cavity16, and conversely, removed from the cavity16, such as during service via forcing lengthwise extending free edges18,20of the sleeve10away from one another against the heat-set bias imparted within at least a portion of the wall12to open the seam14against the self-closing, heat-formed biasing force by an amount sufficient to introduce or remove the elongated members M through the opened split seam14.

The non-woven wall12forms the entirety of the sleeve10, unless a further layer is desired, as discussed below. Accordingly, the construction of the sleeve10eliminates the requirement for additional layers of material to provide protection or other functions, e.g. curling. The material of the nonwoven wall12is constructed, at least in part, of any type and combination of heat-formable fibrous materials. The material may be selected as an abrasion resistant, flexible, resilient, acoustic dampening polymeric material, such as polyester, for example. The exemplary selected fibrous material may be, without limitation, non-woven poly(ethylene terephthalate) (PET). The material may include a base polymeric material (such as PET, by way of example and without limitation) combined with any number and type of polymeric or non-polymeric filler materials (e.g., chopped waste fabric, shop rags, Asian cardboard, etc.). The sleeve10is well suited to protect the elongate members M within the cavity16against abrasion, vibration and damage, while also inhibiting the elongate members M from rattling and squeaking, or otherwise producing unwanted harshness and/or noise. In addition, as a result of the materials and processes used to construct the sleeve10, the sleeve10is both economical in manufacture and in use.

The sleeve10can be constructed from a flat or substantially flat sheet of the non-woven material having an initial uniform thickness (t,FIG. 2) extending between opposite inner and outer sides19,21and a uniform density over its entirety. The non-woven material for the sleeve10will have a designated length as well as a designated width. The selected length will correspond at least generally to the finished length of the sleeve10that extends between opposite ends23,25of the sleeve. The selected width will correspond generally to the sleeve circumference, and thus determines the diameter of the sleeve10that is desired, but, as shown inFIGS. 1-3, the selected width extending between the opposite edges18,20should be provided so that when the sleeve10is in its relaxed or substantially relaxed state and in its closed, tubular configuration, the edges18,20along the split seam14overlap and extend beyond one another, if desired, to bound the cavity16about its entire circumference.

The substantially planar sheet of non-woven material, upon being initially constructed, is further processed in a melting or heat-forming operation such that at least one first portion, also referred to as first band portion, and shown as a circumferentially extending first band portion22(extends across the width of the sleeve from one edge18to the opposite edge20) is provided having an associated first density of the nonwoven material, and further such that there is at least one second portion24, also referred to as second band portion24, and shown as a circumferentially extending second band portion24(extends across the width of the sleeve from one edge18to the opposite edge20) provided having an associated second density that is different than that of the first density. As illustrated in FIGS.1-4, there is preferably a plurality of such first and second band portions22,24alternating along the length of the sleeve10, such that the first band portions22isolate the second band portions24from one another, and vice versa. The first and second band portions22,24may be arranged in alternating sequential manner along a part of the sleeve's length or the entire length of the sleeve10, with each pair of adjacent first band portions22being separated and spaced axially from one another by an intervening second band portion24, and vice versa. The axially extending width of the corresponding first and second band portions22,24can be precisely controlled to provide the desired amount of flex (provided by the individual first band portions22) and rigidity and curl (provided by or substantially by the individual second band portions24) to the sleeve10. The second density of the second band portions24is greater than the first density of the first band portions22as a result of being heat-set and compressed. It will further be seen that the thickness (t1) of the first band portions22is relatively greater than the thickness (t2) of the second band portions24. The reduced thickness t2 of the second band portions24relative to the thickness t1 of the first band material may be attributed solely to the increased densification of the second band material caused during heat-setting of the second band portions24. The first density of the first band material in the first band portions22may remain the same as, or substantially the same as, the starting density of the sheet of non-woven material used to make the sleeve10, and as such, the thickness t1 of the first band portions22can remain the same or substantially the same as the original thickness t of the nonwoven material.

The second band portions24of higher or increased density may be heat-set into a curled configuration corresponding to that ofFIGS. 1-3. Such heat-setting imparted within the second band portions24has the effect of imparting a self-curling attribute to the entire sleeve10, including the first band portions22that may not in themselves be heat-set, but which nonetheless curl because they are influenced by the closely neighboring heat-set second band portions24. The heat-setting may be imparted during the shaping process of the sleeve10and may include passing the nonwoven sheet material between two rollers that may selectively compress and heat the portions of the sleeve10corresponding to the second band portions24while not compressing other portions corresponding to the first band portions22at all, or at least to a lesser extent than the second portions24. The selective heating and rollers may impart both the increased relative density of the second band portion24as well as imparting the self-curling properties to the second band portions24. The same heat-setting can be achieved by a press and by using conductive or ultrasonic heating to the selected second band regions24only. As a result of being compressed and heat-set, the second band portions24are relatively stiff and relatively hard as compared to the softer and more flexible first portions22. As can be seen in the drawings, the heat-setting causes the inner side19to remain smooth, while causing the outer side21to take on an undulating form of alternating peaks P and valleys V. This is due to the material within the second band portions24being compressed and heat-set along the outer side21, while the inner side19is supported against a flat or smooth surface during the heat-setting process. As such, the inner side19remains smooth against the elongate member M.

The resultant non-woven sleeve10has the benefit of being self-curling by virtue of the heat-set, densified second band portions24, and also has the benefit of being flexible and bendable about corners by virtue of the soft and flexible first band portions22. By staggering the first and second portions22,24axially along the length of the sleeve10, the sleeve10is self-curling, flexible, and yet possesses high crush strength. As illustrated inFIG. 4, the sleeve10can be readily wrapped about an elongated member M (e.g., a wire harness) that extends or is arced along a bend or curve. The non-heat seat first portions22provide the primary ability of the sleeve10to be flexed, wherein the first portions22are able to stretch and compress as needed to allow the sleeve10to bend without kinking or without causing the spit seam14to open. In addition, the heat-set second portions24act to bias the opposite edges18, about the longitudinal axis17and to maintain the wall12in its self-wrapped tubular configuration, while also providing the sleeve10with enhanced hoop strength to prevent the sleeve10from being crushed. Accordingly, the sleeve10is self-curled and closed about the harness M due to the self-curling second band portions24, but is also able to flex and bend along its length due to the relatively soft and flexible first band portions22so as to follow the curvature of the wire harness M.

FIGS. 3A-3Cillustrate an alternative or optional feature whereby a layer of foil26is added to one side or both sides of the sleeve10. InFIG. 3A, the layer of foil26is bonded to the inner side19of the sleeve10; inFIG. 3Bthe layer of foil26is bonded to the outer side21of the sleeve10, and inFIG. 3Ctwo layers of foil26are bonded to both the inner and outer sides19,21of the sleeve10. The remaining body of the sleeve10is otherwise non-woven material as described above. It should be recognized that the layer(s) of foil26can be bonded to their respective sides19,21before heat-setting the sleeve10, thereby avoiding having to uncurl the wall12to apply the layer(s)26.

InFIG. 5, a sleeve110constructed in accordance with another aspect of the invention is shown, wherein the same reference numerals, offset by a factor of 100, are used to identify like features. The sleeve110is similar to the sleeve10in that it is a self-wrapping sleeve as a result of being heat-formed in construction. The sleeve110has a wall112that is initially constructed as a substantially flat non-woven material that is subsequently heat-formed into a biased, self-wrapping tubular configuration to form the tubular sleeve110.

The wall112is similar to the wall12in that it is heat-set to take on its curled configuration, forming a split seam114extending along the length of the sleeve110. A generally tubular cavity116is readily accessible along a central longitudinal axis117of the sleeve110so that elongate members M can be readily disposed radially into the cavity116, and conversely, removed from the cavity116by forcing lengthwise extending free edges118,120away from one another, whereby the edges118,120return under the bias imparted within the wall112upon release of the external force.

The wall112is constructed initially the same as the wall12, and thus, it is constructed as a substantially planar sheet of non-woven material, from the same materials discussed above for the wall12, having an initial uniform thickness extending between opposite inner and outer sides119,121and having a uniform or substantially uniform density over its entirety. Upon being initially constructed, the wall112is further processed in a melting or heat-forming operation such that at least one first portion, also referred to as first band portion, and shown as a plurality of isolated first portions122are provided having an associated first density of the nonwoven material, and further, such that there is at least one second portion124, also referred to as second band portion, and shown as a continuous, symmetrically patterned second portion124extending over the entirety of the outer side121having an associated second density that is different than that of the first density. The second density of the second band portion124is greater than the first density of the first band portions122as a result of being heat-set and compressed, thereby providing the second portion124with a reduced, densified thickness relative to the thickness of the first portions122, as discussed above for the wall12. As illustrated inFIG. 5, the second portion124isolates the first portions122from one another, thereby forming islands of the first portions122, shown as being generally diamond-shaped, though other shapes are contemplated, e.g. honeycomb, spiral, and otherwise. Other than the shape and configurations of the first and second portions122,124, the construction and resulting sleeve110is the same as discussed above for the sleeve10. The function of the first and second portions122,124is the same as described above for the sleeve10, and thus, no further discussion is believed necessary.

The foregoing description is exemplary rather than limiting in nature, and as such, it is to be understood that the above detailed description is with regard to some presently preferred embodiments, and that other embodiments readily discernible from the disclosure herein by those possessing ordinary skill in the art are incorporated herein and considered to be within the scope of any ultimately allowed claims.