Tubular knit fabric having alternating courses of sliver fiber pile and cut-pile for paint roller covers

A tubular knit fabric is disclosed that is manufactured with a pile extending from the outer side thereof and in an extended length, small diameter configuration, the tubular knit pile fabric subsequently being separable into shorter tubular segments that may be secured to paint roller cover cores to produce seamless paint rollers. The knit paint roller cover fabric of the present invention is manufactured in a tubular segment with cut-pile and sliver pile segments disposed in alternating courses and extending from the outside of the tubular knit paint roller cover fabric. The tubular knit paint roller cover fabric of the present invention is also manufactured in a size that makes it appropriate for installation onto paint roller cover cores.

BACKGROUND OF THE INVENTION

The present invention relates generally to knit pile fabrics that may be used to produce paint rollers, and more particularly to a tubular knit pile fabric that is manufactured with the pile extending from the outer side thereof and in an extended length, small diameter configuration, the tubular knit pile fabric subsequently being separable into shorter tubular segments that may be secured to paint roller cover cores to produce seamless paint rollers.

The two inventions which have had the greatest impact on paint application are the invention of the paint roller in the 1930's and the development of water-based paint in the late 1940's. While water-based paints are easy to mix, apply, and clean up, there is little doubt that the paint roller has been the greatest single time saving factor in the paint application process, allowing large surfaces to be painted with a uniform coat of paint quickly and easily. Typically, paint rollers are comprised of two components, namely a handle assembly and a paint roller cover for installation onto the handle assembly.

The handle assembly consists of a grip member having a generally L-shaped metal frame extending therefrom, with the free end of the metal frame having a rotatable support for a paint roller cover mounted thereon. The paint roller cover consists of a thin, hollow cylindrical core which fits upon the rotatable support of the handle, with a plush pile fabric being secured to the outer diameter of the paint roller cover. The core may be made of either cardboard or plastic material, with which material is used for the core generally being determined based upon the selling price of the paint roller cover. The pile fabric is traditionally applied as a strip which is helically wound onto the outer surface of the core with adjacent windings of the fabric strip being located close adjacent each other to provide the appearance of a single continuous pile fabric covering on the core.

Typically, the pile fabric is a dense knitted pile fabric, which may be knitted from natural fibers such as wool or mohair, synthetic fibers such as polyester, acrylic, nylon, or rayon, or from a blend of natural and synthetic fibers. The knitting is typically performed on a circular sliver knitting machine, which produces a tubular knitted base material with a knit-in pile in tubular segments which are approximately fifty-eight inches (1473 millimeters) in circumference by thirty to fifty yards (27.43 meters to 45.728 meters) long (depending on fabric weight).

Generally, sliver knitting is a knitting process which locks individual pile fibers directly into a lightweight knit backing or base material in a manner wherein the pile fibers extend from one side of the knit base material. The knit base material itself is made from yarn, which may be knitted in a single jersey circular knitting process on a circular knitting machine, with closely packed U-shaped tufts of the fibers being knitted into the knit base material which anchors them in the completed pile fabric. The free ends of the fibers extend from one side of the knit base material to provide a deep pile face. The knit base material is typically made of synthetic yarns, with the pile being made of a desired natural or synthetic fiber, or a blend of different fibers.

Such fabrics are illustrated, for example, in U.S. Pat. No. 1,791,741, to Moore, U.S. Pat. No. 2,737,702, to Schmidt et al., U.S. Pat. No. 3,226,952, to Cassady, U.S. Pat. No. 3,853,680, to Daniel, U.S. Pat. No. 3,894,409, to Clingan et al., U.S. Pat. No. 4,236,286, to Abler et al., U.S. Pat. No. 4,513,042, to Lumb, and U.S. Pat. No. 6,766,668, to Sinykin, all of which patents are hereby incorporated herein by reference. Sliver knit high pile fabrics have been widely used for many years in the manufacture of imitation fur fabrics, and also have found use, for example, as linings for overcoats and footwear, as coverings for stuffed toys and floors, in applications in pet beds, case liners, boot and slipper liners, medical pads, and blankets, and, of course, as coverings for paint roller covers.

The components of the knitted fabric are a yarn, which is used to knit the fabric's knit base material, and fibers which are supplied in a “sliver” rope, which consists of fibers which are all longitudinally oriented in a rope which is typically less than three inches (76 millimeters) in diameter. The fibers are loose fibers of either a single type or a uniform blend of multiple types of fibers. The fiber mix will determine the performance, density, texture, weight, patterning, and color of the finished pile fabric.

The fibers are typically blown together in an air chamber to blend them, and then are carded in carding machines that “comb” the fibers to align them in parallel with each other. The fibers are then gathered into a soft, thick rope which is called “sliver” (which is the derivation for the term “sliver knit”) or “roving.” The yarn and the sliver are supplied to the circular knitting machine, which typically has eighteen heads and produces a tubular knit pile fabric which is approximately fifty-eight inches (1473 millimeters) in circumference. (Thus, when the tubular knit pile fabric is slit longitudinally, the fabric is approximately fifty-eight inches (1473 millimeters) wide.)

Such knitting machines are well known in the art, and are illustrated in U.S. Pat. No. 3,894,407, to Clingan et al., U.S. Pat. No. 3,896,637, to Thore, U.S. Pat. Nos. 4,532,780 and 4,592,213, both to Tilson et al., U.S. Pat. Nos. 5,431,029, 5,546,768, 5,577,402, 5,685,176, and 6,016,670, all to Kukrau et al., and U.S. Pat. No. 6,151,920, to Schindler et al., all of which patents are hereby incorporated herein by reference. Examples of commercial versions of such knitting machines are the Model SK-18 II Sliver Knitter and the Model SK-18J II Sliver Knitter which are available from Mayer Industries, Inc. of Orangeburg, S.C.

The first commercial circular sliver knitting machine had seven heads, and commercially-available circular knitting machines today have between seven and eighteen heads. Eighteen head knitting machines have upwards of one thousand needles, and produce tubular knitted segments that are approximately nineteen inches (483 millimeters) in diameter (fifty-eight inches (1473 millimeters) in circumference). All of these circular sliver knitting machines produce tubular knitted pile fabric segments having the pile located on the inside. Such circular sliver knitting machines are incapable of either producing tubular knitted pile fabric segments having the pile on the outside or small diameter tubular knitted pile fabric segments.

Following the manufacture of the tubular knitted pile segments on a circular sliver knitting machine, the tubular knitted pile segments are slit longitudinally to produce extended knitted pile segments of fabric which are typically fifty-eight inches (1473 millimeters) wide by thirty to fifty yards (27.43 meters to 45.728 meters) long. These extended knitted pile segments of fabric are then tensioned longitudinally and transversely, stretched to a sixty inch (1524 millimeter) width or greater to guarantee the proper number of two and seven-eighth inch (73 millimeter) strips, and back coated (on the non-pile side of the knit base material) with a stabilized coating composition such as a clear acrylic polymer. The coating composition which is coated onto the non-pile side of the knit base material is then processed, typically by heat, to stabilize the coated, extended knitted pile segment. The heating operation dries and bonds the coating composition to the knit base material, producing a fabric which is essentially lint-free.

The coated, extended knitted pile segment can then be subjected to a shearing operation to achieve a uniform pile length, with the sheared fibers being removed by vacuum, electrostatically, or by any other known removal technique. The pile density, the nap length, and the stiffness of the fibers are varied based upon custom specifications and the particular characteristics of the paint roller cover that are desired.

The sheared, coated, extended knitted pile segment is then slit into a plurality of two and seven-eighths inch (73 millimeter) wide knitted pile fabric strips, of which there are typically twenty for a sixty inch (1524 millimeter) wide fabric segment. Following this slitting operation, the strips must be vacuumed to remove stray fibers and lint. The knitted pile fabric strips are rolled onto a core to produce twenty rolls of knitted pile fabric strips, each of which is thirty to fifty yards long. These rolls of knitted pile fabric strips may then be shipped to a paint roller cover manufacturer. Alternately, a plurality of standard lengths of the fabric may be seamed together to produce an extended length fabric strip which may be helically wound in consecutive rows upon a core as taught in U.S. Pat. Nos. 6,502,779, 6,685,121, 6,902,131, 6,918,552, and 6,929,203, all to Jelinek et al., all of which patents are hereby incorporated herein by reference.

Both the standard length rolls of knitted pile fabric strips and the rolls of extended length knitted pile fabric strips have substantial material costs and labor costs that are incurred in the manufacturing process after the circular knitting process. The material costs include the cost of the coating material, losses due to fly (fly are extra fibers that come loose from the knitted pile fabric), losses during the cutting of the sixty inch (1524 millimeter) wide fabric segment into twenty knitted pile fabric strips, and seam losses throughout the operation. The labor costs include the costs to perform the coating process, the brushing, the second pass shearing, and all of the finishing steps within the traditional sliver knit operation including slitting and continuously coiling the fabric slits.

Paint roller covers are manufactured by using a hollow cylindrical core made of cardboard or thermoplastic material which has the knitted pile fabric strip helically wound around the core. During the manufacture of paint roller covers, the knitted pile fabric strips are secured to the core either by using adhesive or epoxy, or by thermally bonding the knitted pile fabric strip in place on a thermoplastic core. For examples of these manufacturing processes see U.S. Pat. No. 4,692,975, to Garcia (the “'975 patent”), U.S. Pat. No. 5,572,790, to Sekar (the “'790 patent”), and U.S. Pat. No. 6,159,320, to Tams et al. (the “'320 patent”), each of which are hereby incorporated by reference.

The '975 patent uses a core that is cut from preformed thermoplastic (e.g., polypropylene) tubular stock. The core is mounted on a rotating spindle, and a movable carriage mounted at an angle to the spindle feeds a continuous strip of knitted pile fabric onto the core, with the carriage moving parallel to the spindle in timed relation to its rotation so that the knitted pile fabric strip is wound on the plastic core in a tight helix. Also mounted to the movable carriage is a heat source for heat softening the thermoplastic core just in advance of the point where the knitted pile fabric strip is applied to the thermoplastic core, such that the knitted pile fabric is heat bonded to the thermoplastic core as it is wound thereupon. The bond formed between the knitted pile fabric and the thermoplastic core is a strong one not subject to separation from exposure to paint solvents.

The '790 patent uses a core that is formed from a strip (or multiple strips) of thermoplastic material that is (are) helically wound about a stationary mandrel. Alternately, the core may be formed by applying liquefied thermoplastic material to a drive belt which transfers the thermoplastic material to the mandrel. A layer of adhesive is then applied to the outer surface of the core, and the knitted pile fabric strip is applied to the core by helically winding the knitted pile fabric strip onto the core. Alternately, the paint roller cover may instead be made by bonding, in a single step, a knitted pile fabric strip to a wound strip of thermoplastic material that is wrapped about the mandrel.

The '320 patent extrudes a cylindrical plastic core through a rotating extruder head that is cooled, with the outer surface of the core then being plasma treated. The knitted pile fabric strip is secured onto the plasma treated outer surface of the core by extruding thin films of first and second epoxy resin subcomponents onto the outer surface of the core as it is extruded, cooled, and plasma treated in a continuous process.

Other variations are also known, particularly in technologies relating to manufacturing pile fabric suitable for use on paint roller covers. For example, instead of using knitted pile fabric, woven pile fabric can be substituted. Woven pile fabric consists of three yarns—a knit base material or warp yarn, a filling or weft yarn, and a pile yarn. The threads of warp yarn are held taut and in a parallel array on a loom, and the threads of weft yarn are woven across the threads of warp yarn in an over/under sequence orthogonal to the threads of warp yarn, with threads of pile yarn being woven into the weave of warp and weft yarns such that the threads of pile yarn extend essentially perpendicularly from one side of the fabric. Such woven pile fabric may be processed in a manner similar to that described above with regard to the processing of knitted pile segments of fabric to produce strips of woven pile fabric that can be helically wound onto paint roller cover cores.

However, all paint roller covers manufactured using the methods described above have a seam. As the strips of fabric are helically wound around the cores, the fabric strips wrap contiguously around the core, thereby creating a helical seam that is located throughout the cover. The seam inevitably produces a less than optimal paint roller cover since a seam can interfere with the uniform application of paint from the paint roller cover. The helical winding process of manufacturing a paint roller cover requires careful attention to contiguous winding. Errors resulting in overlapped fabric or gaps in the contiguous winding process often occur, resulting in increased scrap or marketing poor quality covers. Such seams have the potential, particularly with short nap paint roller covers, to produce a seam mark or stippling effect on the surface being painted, particularly if the paint being applied combines with the seams to produce a more pronounced defective characteristic in the surface being painted.

An examination of prior technology in the paint roller cover arts reveals that this problem has been recognized in the past, with several solutions that have been proposed to deal with the challenge presented by the presence of seams in paint roller covers. The first of these, U.S. Pat. No. 2,600,955, to Barnes et al., which patent is hereby incorporated herein by reference, discloses a paint roller cover made from a segment of canvas tubing that has yarn loops sewn therethrough, with the ends of the loops on the outside of the segment of the canvas tubing being cut. This approach is certainly far too expensive to represent a viable solution, and would not compare well to currently commercially available paint roller covers in the quality of the paint coat that could be applied.

Another approach is shown in U.S. Pat. Nos. 2,704,877 and 2,752,953, both to Arnold Schmidt, which patents are hereby incorporated herein by reference, which patents are related and disclose a tubular knitted pile fabric that is stated to have been manufactured on an apparatus disclosed in U.S. Pat. No. 1,849,466, to Moore, which patent is hereby incorporated herein by reference. The apparatus disclosed in Moore, which is hand operated, was stated in several related patents to Sannipoli et al. (U.S. Pat. Nos. 2,920,372, 2,944,588, and 3,010,867, which patents are hereby incorporated herein by reference) to be capable of manufacturing a seamless tubular knitted sleeve in which the pile is located on the interior of the sleeve, thereby requiring that the sleeve be inverted prior to mounting it on a core to form a paint roller cover. As such, the apparatus disclosed in Moore is incapable of manufacturing a knitted sleeve in which the pile is located on the exterior of the sleeve.

The Sannipoli et al. patents inverted the tubular knitted sleeve by positioning it within a hollow tube and pulling one end of the tubular knitted sleeve around the end of the tube and pushing successive portions of the tubular knitted sleeve along the outside of the tube. The Arnold Schmidt '877 patent (which failed to disclose how it inverted the knitted sleeve with the pile on the interior thereof) disclosed a machine for treating and shearing inverted tubular knitted sleeves, and the Arnold Schmidt '953 patent disclosed using the inverted, treated, and sheared tubular knitted sleeves by stretching them and pulling them over a tube or shell to form a paint roller.

The problem that has prevented the inventions of the Arnold Schmidt patents and the Sannipoli et al. patents from being either practical or commercially successful is that the process of inverting a tubular knitted sleeve having the pile on the interior of the sleeve inevitably damages the fabric of the tubular knitted sleeve. When the fabric is inverted, the material of the fabric is deformed due to stretching that occurs during the process of inverting the tubular knitted sleeve. This deformation tends to increase the diameter of the tubular knitted sleeve, thus requiring it to be stretched lengthwise to restore it to its former diameter. Not only is this process difficult and expensive, but it also results in variable density of the fabric as well as introducing the prospect of adhesive or thermoplastic bleed-through within the stitches. Such problems will result in unacceptable product quality in paint roller covers made from this type of fabric.

It has been determined that the inverting approach taught by the Sannipoli et al. patents and useable by the Arnold Schmidt patents has three drawbacks that make it impracticable. The first drawback of the inverting method is that it requires a high degree of manual operation in that it requires cutting of the tubular knitted sleeves to size and placement of the tubular knitted sleeves into the tubes of the inverting machine. The second drawback of the Sannipoli et al. method is that only relatively short length tubular knitted sleeves representing a single paint roller cover (typically nine inches (229 millimeters)) can be processed at a time, which makes the method inherently unsuitable for mass production.

The third, and by far the most serious, drawback of the Sannipoli et al. method is that the process of inverting the tubular knitted sleeves inevitably results in stretching the tubular knitted sleeves so that they will not snugly fit on the paint roller cover cores, potentially creating creases in a high percentage of them when they are adhesively secured to the paint roller cover cores. This results in an unacceptably high percentage of them being defective and necessitating them being scrapped, resulting in an unacceptably high scrap cost. Predictably, the inventions taught in the Sannipoli et al. patents and the Arnold Schmidt patents have never found commercial acceptance due to these serious disadvantages.

The above-incorporated by reference U.S. patent application Ser. No. 11/740,119 discloses a tubular sliver knitted pile fabric which is manufactured with the sliver pile side facing outwardly rather than inwardly and with a diameter suitable for mounting on a paint roller cover core in a seamless manner. While the tubular knitted pile fabric in this patent application is disclosed as being for installation onto a core member, the method used to install the tubular knitted pile fabric onto the outer surface of the core member is not disclosed.

While this tubular sliver knitted pile fabric has been found to be quite satisfactory, it was recognized that it would also be desirable to provide an alternative tubular pile fabric which has a cut-pile made of yarn rather than sliver fibers The above incorporated by reference, commonly assigned, and co-pending U.S. patent application Ser. No. 12/116,022 provides a tubular cut-pile knit paint roller cover fabric suitable for use in the manufacture of a paint roller cover. A cut-pile knit paint roller cover fabric, in accordance with co-pending U.S. patent application Ser. No. 12/116,022 is manufactured with the pile side facing outwardly rather than inwardly, thereby obviating the need to invert it prior to mounting it on a paint roller cover core. A cut-pile knit paint roller cover fabric, in accordance with co-pending U.S. patent application Ser. No. 12/116,022 can have a size suitable for mounting on a paint roller cover core in a seamless manner, without cutting except to a length fitting the length of paint roller cover core material on which the cut-pile knit paint roller cover fabric is to be mounted.

A cut-pile knit paint roller cover fabric, in accordance with U.S. patent application Ser. No. 12/116,022 can also be provided in a form that is suitable for use in its application on a paint roller cover without experiencing any significant degradation of the cut-pile knit paint roller cover fabric due to its contact with a wide variety of paints, enamels, stains, etc. A cut-pile knit paint roller cover fabric, in accordance with U.S. patent application Ser. No. 12/116,022 can further be provided in a form in which the pile loops are securely retained by the knit base material such that the shedding of pile fibers from the cut-pile knit paint roller cover fabric is minimized. In a cut-pile knit paint roller cover fabric, in accordance with U.S. patent application Ser. No. 12/116,022, the cut-pile knit paint roller cover fabric is manufacturable in extended length segments that may later be cut to tubular segments of any desired length.

A cut-pile knit paint roller cover fabric, in accordance with U.S. patent application Ser. No. 12/116,022 can further be of construction which is both durable and long lasting when it has been secured to a paint roller cover core, and the resulting paint roller cover should provide the user with an acceptably long lifetime. A cut-pile knit paint roller cover fabric, in accordance with U.S. patent application Ser. No. 12/116,022 is inexpensive to manufacture, thereby affording broad market appeal. Finally, a cut-pile knit paint roller cover fabric, in accordance with U.S. patent application Ser. No. 12/116,022, provides all of the aforesaid advantages without incurring any substantial relative disadvantage.

Having successfully provided tubular knit paint roller cover fabric in co-pending U.S. patent application Ser. No. 11/740,119 having an outwardly extending pile formed entirely from sliver fibers, and having successfully provided tubular knit paint roller cover fabric in co-pending U.S. patent application Ser. No. 12/116,022 having an outwardly extending pile formed entirely of cut-pile fibers, it is desirable to provide a tubular knit paint roller cover having courses of outwardly extending pile formed entirely of sliver fibers successively alternating with courses of outwardly extending pile formed entirely of cut-pile fibers. Given the substantial differences in the knitting processes utilized for forming tubular knit paint roller cover fabric having an outwardly extending pile formed entirely from sliver fibers, as disclosed in co-pending U.S. patent application Ser. No. 11/740,119, as compared to the knitting processes utilized for forming tubular knit paint roller cover fabric having an outwardly extending pile formed entirely of cut-pile fibers, as disclosed in co-pending U.S. patent application Ser. No. 12/116,022, the challenges to be surmounted in providing a tubular knit paint roller cover having courses of outwardly extending pile formed entirely of sliver fibers successively alternating with courses of outwardly extending pile formed entirely of cut-pile fibers are significant.

It is accordingly the primary objective of the present invention that it provide a tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile suitable for use in the manufacture of a paint roller cover. It is a related principal objective of the present invention that the tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile be manufactured with the pile side facing outwardly rather than inwardly, thereby obviating the need to invert it prior to mounting it on a paint roller cover core. It is an additional related principal objective of the present invention that the tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile be of a size suitable for mounting on a paint roller cover core in a seamless manner, without cutting except to a length fitting the length of paint roller cover core material on which the cut-pile knit paint roller cover fabric is to be mounted.

It is also an objective of the present invention that the tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile be suitable for use in its application on a paint roller cover without experiencing any significant degradation of the cut-pile knit paint roller cover fabric due to its contact with a wide variety of paints, enamels, stains, etc. It is a further objective of the present invention that the tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile be manufactured in a manner in which the pile loops are securely retained by the knit base material such that the shedding of pile fibers from the cut-pile knit paint roller cover fabric is minimized. It is a still further objective of the present invention that the tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile be manufacturable in extended length segments that may later be cut to tubular segments of any desired length.

The tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile of the present invention must also be of construction which is both durable and long lasting when it has been secured to a paint roller cover core, and the resulting paint roller cover should provide the user with an acceptably long lifetime. In order to enhance the market appeal of the tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile of the present invention, it should also be inexpensive to manufacture to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-pile of the present invention be achieved without incurring any substantial relative disadvantage.

SUMMARY OF THE INVENTION

The present invention meets the above defined objectives by providing a tubular knit fabric suitable for use on paint roller covers having an outwardly extending pile formed from a plurality of cut-pile segments and tufts of sliver knit fabric disposed in alternating successive courses in the knit pile fabric.

In one form of the invention, a knit pile fabric suitable for use on paint roller covers, includes a knitted base fabric having a tubular configuration defining an outside and an inside, said base fabric having a predetermined number of wales located adjacent each other and arranged around the circumference of said base fabric. The base fabric has successive courses, each of which is knit after a preceding course, with the base fabric including a plurality of loops, and each loop in any particular wale being knitted through a loop in the preceding course in said particular wale from the outside to the inside of said tubular configuration of said base fabric. The pile is formed partly from a plurality of cut-pile segments, each having opposite ends with a loop portion located therebetween. The loop portion of each of the plurality of cut-pile segments is knitted together with a loop of the base fabric into the base fabric, in such a manner that opposite ends of the plurality of cut-pile segments extend outwardly from the base fabric and form a part of the pile of the knit fabric. The pile is also formed partly from a plurality of tufts of sliver fibers, with each of the tufts of sliver fibers having opposite ends with a loop portion located therebetween. The loop portion of each of the plurality of tufts of sliver fibers is knitted together with a loop of the base fabric into the base fabric in such a manner that the opposite ends of the plurality of tufts of fibers extend outwardly from the base fabric and form a portion of the pile of the knit pile fabric. The plurality of cut-pile segments and the plurality of tufts of sliver knit fabric are disposed in alternating successive courses in the knit pile fabric.

The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a knit fabric having alternating courses of sliver fiber pile and cut-pile is provided that has several key characteristics that radically differentiate it from prior knit fabrics. The first and most important of these differentiating factors is that the knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention is manufactured in a tubular segment with the pile located on the outside of the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile rather than on the inside, in this manner obviating the need to invert the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile and thereby deform the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile. The second key differentiating factor is that the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention is manufactured in a size that makes it appropriate for installation onto paint roller cover cores, which typically have an inner diameter of approximately one and one-half inches (38 millimeters) and an outer diameter of approximately one and five-eighths inches (41 millimeters) to one and three-quarters inches (44 millimeters).

The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile in one form of the present invention has a knitted base material that is knit in a single jersey circular knitting process on a radically redesigned circular knitting machine that is designed to produce the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention. The jersey knitted knit base material of the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention has a plurality of courses (which are rows of loops of stitches which run across the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile (around the circumference of the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile)) and a plurality of wales (which are vertical chains of loops in the longitudinal direction of the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile). The number of wales together with the gauge (the number of courses per circumferential inch) determines the diameter of the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention. In the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention, the number of wales can vary between approximately forty and one hundred wales, with the currently preferred embodiment having approximately fifty wales.

In alternating courses, the knitting of the stitches of the knit base material is used to anchor tufts of sliver fibers, and also to anchor loops of pile yarn which are cut, with the free ends of the pile loops extending from the outer side of the knit base material of the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention. As the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention is knit, the length of the sliver fibers and the height of the outermost ends of the cut-pile loops may be varied to product longer or shorter pile, and will typically vary between approximately one-quarter inch (6.35 millimeters) and three inches (76 millimeters).

The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention may be manufactured in extended lengths, which may be cut to the desired lengths subsequent to its manufacture. Notably, the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention does not require inverting since the pile is located on the outside. It will be appreciated by those skilled in the art that the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention does not require slitting since it is produced to fit over paint roller cover cores rather than to be wound helically around paint roller cover cores. Thus, all of the post-knitting material and labor costs mentioned above with reference to the manufacture of standard or extended length rolls of knitted pile fabric strips are not incurred in the manufacturing of the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention.

The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention may be cut to single paint roller length (typically nine inches (229 millimeters)), or it may be cut to fit a longer length paint roller cover core segment, such as, for example, sixty-four inches (1625 millimeters). Following application of the longer length paint roller cover core segment to the longer length paint roller cover core segment, it may be cut into smaller paint roller covers, such as, for example, seven nine inch (229 millimeter) paint roller covers. Alternately, the extended paint roller cover segments may be manufactured at the same facility manufacturing the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile, with the extended paint roller cover segments being shipped to a paint roller manufacturer for finishing.

Finishing either the cut-to-length paint roller covers or the extended paint roller cover segment may include combing the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile on the paint roller cover and shearing the fabric having alternating courses of sliver fiber pile and cut-fiber pile on the paint roller cover. These finishing steps may occur either before or after cutting the paint roller covers to the desired length. Finally, the edges of the paint roller covers are beveled, and any loose pile fibers may be vacuumed off. The finishing of extended paint roller cover segments may be performed using the MBK Maschinenbau GmbH paint roller finishing machine distributed by Roller Fabrics, an Edward Jackson (Engineer) Limited finishing machine, or other equipment custom built by individual paint roller manufacturers.

The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention may be mounted onto a paint roller cover core in any desired manner. Different ways of adhering the tubular knit paint roller cover having alternating courses of sliver fiber pile and cut-pile onto a paint roller cover core may be used as desired. The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention is suitable for paint roller cover cores made according to any of a variety of ways.

It may therefore be seen that the present invention provides a tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile that is suitable for use in the manufacture of a paint roller cover. The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention is manufactured with the pile side facing outwardly rather than inwardly, thereby obviating the need to invert it prior to mounting it on a paint roller cover core. The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention is of a size suitable for mounting on a paint roller cover core in a seamless manner, without cutting it except for cutting it to a length fitting the length of paint roller cover core material on which the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile is to be mounted.

The tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention is well suitable for use in its application on a paint roller cover, and will not experience any significant degradation of the tubular cut-pile knit paint roller cover fabric due to its contact with a wide variety of paints, enamels, stains, etc. The tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention is manufactured in a manner in which the pile loops are securely retained by the knit base material such that the shedding of pile fibers from the tubular knit paint roller cover fabric having alternating courses of sliver fiber pile and cut-fiber pile is minimized. The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention is also manufacturable in extended length segments that may later be cut to tubular segments of any desired length.

The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention is of a construction which is both durable and long lasting when it has been secured to a paint roller cover core, and the resulting paint roller cover will provide the user with an acceptably long lifetime. The tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention is also inexpensive to manufacture, thereby enhancing its market appeal and to affording it the broadest possible market. Finally, all of the aforesaid advantages and objectives of the tubular knit paint roller fabric having alternating courses of sliver fiber pile and cut-fiber pile of the present invention are achieved without incurring any substantial relative disadvantage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1shows a first exemplary embodiment of a tubular-shaped knitted covering100for a paint roller having pile fibers102made up of alternating courses of sliver fiber pile and cut-pile extending from a lightweight knit backing or base material104, that is knitted according to one of the methods and using an apparatus of the type disclosed in commonly assigned U.S. patent application Ser. No. 11/871,307 and in commonly assigned U.S. patent application Ser. No. 12/249,455. As will be readily understood by those having skill in the art, the tubular knit segment100, having a pile102made up of alternating courses of sliver fiber pile and cut-pile, may be readily pulled over and affixed to a core106by an adhesive105, as illustrated inFIGS. 2-4, to form a completed roller cover107according to one of the methods shown in the inventor's commonly assigned U.S. patent application Ser. Nos. 11/740,119, 12/015,612, 12/100,050, 12/132,774, or another appropriate manner, without the necessity for resorting to helically wrapping a strip of pile fabric about the core as was required in prior roller covers.

Referring next toFIG. 5, a segment of the tubular knit segment100having a pile102made up of alternating courses of sliver fiber pile and cut-pile is shown in schematic form, from the outside thereof, to illustrate the knit of the knit base material104, and the manner in which tufts of sliver fiber108and loops of cut-pile fiber110are woven into the knit base material104to form the pile102made up of alternating courses of sliver fiber pile and cut-pile. Those skilled in the art will at once realize that while the tufts111of the sliver fiber108shown inFIG. 5include only a few fibers each for added clarity and understanding of the construction of the pile fabric20, tufts111of sliver fibers108in the pile102of the tubular sliver knit segment100will actually include sufficient sliver pile fibers108to help form a pile102that is sufficiently dense for the intended use of the tubular shaped knit segment100in the manufacture of a paint roller cover107.

The preferred embodiment of the knit paint roller fabric having alternating courses of sliver fiber pile and cut-pile of the present invention produces a tubular knit paint roller fabric segment100, having alternating courses of sliver fiber pile and cut-pile, as shown inFIG. 1that may be continuously knitted in an extended length. It may be seen from a top edge112of the knit base material104that the tubular knit segment100has an essentially circular cross section. The tubular knit segment100may be knitted in as long a length as desired, notwithstanding thatFIG. 1only shows a relatively short segment of the tubular knit segment100.

The tubular knit segment100having a pile102made up of alternating courses of sliver fiber pile and cut fiber pile may be knit in a highly modified single jersey circular knitting process on a radically redesigned circular knitting machine of the type generally indicated schematically in an exemplary embodiment of a knitting machine200inFIGS. 6 and 7. The construction and operation of an embodiment of a circular knitting machine of the type illustrated inFIGS. 6 and 7is also described in considerably greater detail in commonly assigned U.S. patent application Ser. Nos. 11/871,307 or 12/249,455, the disclosures of which are incorporated herein in their entireties.

The exemplary embodiment of the knitting machine200, shown herein inFIGS. 6 and 7, is specifically configured for forming the tubular-shaped knitted roller covering100, as shown inFIGS. 1 and 5, having multiple successively disposed knitted courses including pile on the outside of the covering. The knitting machine200is configured for simultaneously knitting two adjacent courses with the pile material being sliver fibers in one course of the two simultaneously knitted courses and the pile material being a single strand of face yarn in the other course of the two simultaneously knitted courses.

As shown inFIGS. 6 and 7, this is accomplished by configuring the knitting apparatus200to include one doffer-type sliver fiber pile feeding apparatus201, and one pile yarn feeding apparatus212. Knitting and forming the face yarn pile course is accomplished using the pile yarn feeding apparatus212, in three stages I1, II1, III1, about substantially the lower right half (as shown inFIG. 7) of a dial216of the knitting machine200, in the manner described in more detail below. In similar fashion, knitting and forming the pile yarn pile course is accomplished using the sliver fiber pile feeding apparatus201, in three stages I2, II2, III2, about substantially the upper left half (as shown inFIG. 7) of a dial214of the knitting machine200.

As shown inFIGS. 6 and 7, the first exemplary embodiment of a knitting apparatus200, for forming the tubular-shaped knitted covering100for a paint roller, or the like, having a pile102extending from an outer surface of the covering includes a dial knitting arrangement214, having: a dial216; a plurality of dial needles146operatively disposed in the dial216; a dial cam box218disposed adjacent to the dial216and operatively connected to the dial needles146; first and second backing yarn feeding arrangements224,222; a pile yarn feeding arrangement220; all operatively mounted on a frame (not shown) and driven through a drive arrangement (not shown).

The frame defines a main vertical axis of rotation226, about which the dial216rotates.

The knitting arrangement200also includes a cylinder knitting arrangement215, having: a cylinder217having an upper end219; a cylinder cam box221disposed outwardly adjacent the cylinder217, and a plurality of cylinder needles152. The cylinder needles152are operatively disposed in the cylinder217and connected to the cylinder cam box221in such a manner that the cylinder needles152move in a direction substantially parallel to the vertical main axis of rotation226as the cylinder217is rotated about the axis226in a synchronized fashion with the dial216.

As best seen inFIG. 7, the dial216has a periphery228thereof, which is substantially circular in the exemplary embodiment of the dial216, and disposed about the main vertical axis of rotation226. As shown inFIGS. 6 and 7, the dial216, in the exemplary embodiment of the knitting apparatus200, also has 56 substantially radially directed dial needle slots229opening in an upward direction, with each dial needle slot229being configured for slidably receiving one of the dial needles146.

As best seen inFIG. 6, the dial cam box218is non-rotatably mounted to the frame closely adjacent the dial216. The dial cam box218includes a downwardly-facing and opening dial cam box cam track230therein.

The dial needles146each have a body232thereof disposed in a respective dial needle slot229. Each of the dial needles146also has a hooked end148that is outwardly extendable beyond the periphery228of the dial216, and a needle cam lobe234extending upward beyond the dial needle slot229and into sliding engagement with the dial cam box needle track230, in such a manner that rotation of the dial216causes the dial needles146to be selectively moveable radially within the dial needle slots229through interaction of the dial needle cam lobes234with the dial needle cam track230. Each dial needle146also includes a latch150(seeFIG. 8) pivotably attached to the body232of the needle146adjacent the hooked end148, and operable in the manner illustrated inFIGS. 8 through 27and described in detail below.

As schematically illustrated inFIGS. 6 and 7, the backing yarn and pile feeding arrangements220,222,224are operatively disposed adjacent the periphery228of the dial216, and adapted for feeding first and second backing yarns240,238, a pile yarn236and pile sliver fibers108to the dial needles146, along selected segments of the periphery228of the dial216, in such a manner that an extended length of tubular-shaped knitted covering100for a paint roller having a pile102extending from an outer surface of the covering100may be knitted with the first exemplary embodiment of the knitting apparatus200, according to the method laid out in detail below with reference toFIGS. 8 through 25.

As shown inFIG. 6, the cylinder needle knitting arrangement215includes the cylinder217, a plurality of cylinder needles152operatively disposed in the cylinder217. The cylinder217has a radially outer periphery242thereof, disposed about the axis of rotation226, and having a plurality of substantially axially directed needle slots244opening in a radially outward direction and also in an upward direction at the upper end219of the cylinder217.

The cylinder cam box221is non-rotatably mounted to the frame and includes a radially inward facing and opening cylinder needle cam track246therein.

As further shown inFIG. 7, the cylinder needles152each have a body thereof which is disposed in a respective cylinder needle slot244of the plurality of cylinder needle slots244, and a hooked end154that is upwardly extendable beyond the upper end219of the cylinder217. Each of the cylinder needles152also includes a cylinder needle cam lobe248which extends radially outward beyond the cylinder needle slot244and into sliding engagement with the cylinder needle cam track246, such that rotation of the cylinder217causes the cylinder needles152to be selectively moveable axially within the cylinder needle slots244through interaction of the cylinder needle cam lobes248with the cylinder needle cam track246. By virtue of this arrangement, the cylinder217and dial216and their respective dial and cylinder needles146,152are operatively connected for synchronized rotation with respect to one another about the axis of rotation226.

It will be further noted, that the cylinder needles152each include a cutting blade portion156disposed adjacent the hooked end154of the needle152rather than having the pivoting latches150(seeFIG. 8) of the dial needles146.

As shown inFIGS. 7 and 19, the cylinder needle knitting arrangement215also includes a pile yarn cutting wheel250, for use in a manner described in greater detail below, for assisting in cutting of the pile yarn236into pile fibers as they are knitted in place in successive alternating courses of the backing yarn240in the manner described in detail below with reference toFIGS. 8 through 25.

As shown inFIG. 5, the foundation of the exemplary embodiment of the tubular knit segment100having a pile102made up of alternating courses of sliver fiber pile and cut fiber pile is the knit base material104. The knit base material104has a plurality of courses (which are rows of loops of stitches which run across the knit fabric), five of which are shown and designated by the reference numerals114,116,118,120and122, and a plurality of wales (which are vertical chains of loops in the longitudinal direction of the knit fabric), three of which are shown and designated by the reference numerals124,126and128. The respective courses114,116,118,120and122are knitted sequentially from the lowest course number to the highest course number.

By way of example, to illustrate the manner in which the courses of looped fiber cut-pile110are knitted, the construction of the portion of the tubular knit segment100in the area of the course120and the wale126will be discussed herein. A backing loop130formed in a backing yarn segment132is located in this area, with a backing loop134formed in a backing yarn segment136being located in the course116below the backing loop130, and a backing loop138formed in a backing yarn segment140being located in the course122above the backing loop130. The backing loop130extends through the backing loop134from the outside to the inside of the tubular knit segment100(shown inFIG. 1), and the backing loop138also extends through the backing loop130from the outside to the inside. It will at once be appreciated by those skilled in the art that this arrangement of backing loops in sequentially knitted courses is completely opposite to the way in which knit fabrics have been knitted on known circular knitting machines.

A cut-pile segment110having a pile loop portion143and opposite pile ends142and144is knitted into the knit base material32together with the backing loop130. The pile loop portion143of that particular cut-pile segment110is located adjacent the top of the backing loop130, and the opposite pile ends142and144of that particular cut-pile segment110extend outwardly from the interior of the backing loop130, above the backing loop134and below the backing loop138. In a similar manner, each of the other cut-pile segments110is knitted into the knit base material104with a different backing loop.

FIGS. 8 through 20illustrate a cut-pile knitting process which may be used to knit the courses of the tubular segment100having cut fiber pile loops110, as shown inFIG. 5, for example. These figures show in sequential fashion how a stitch is formed. Each of these figures shows a dial needle146having a hook148located at the distal end thereof and a latch150that has a proximal end that is pivotally mounted at a location on the dial needle146that is proximal of the hook148. The latch150can pivot between a closed position (shown inFIGS. 8,12,17,18,19, and20) in which the distal end of the latch150contacts the end of the hook148to form an enclosed area with the hook148, and an opened position (shown inFIGS. 10,14, and20) in which the distal end of the latch150forms a small acute angle with the proximal end of the dial needle146.FIGS. 9,11,13, and16show the latch150in intermediate positions.

Each ofFIGS. 8 through 20also shows two cylinder needles152that are respectively located below and on opposite sides of the distal end of the dial needle146. The cylinder needles152each have a hook154located at the distal end thereof, and a tapered cutting edge156located a short distance from the hook154. The tapered cutting edge156is coplanar with the hook154, and extends outwardly progressively further as it extends further from the hook154. The dial needle146and the cylinder needles152are oriented essentially orthogonally to each other.

FIGS. 8 through 20show the tubular cut-pile knit segment100in phantom lines, with only several backing loops in a single wale being shown in solid lines. Specifically, sequential backing loops158,160and162are shown in each ofFIGS. 8 through 20, with the backing loops158,160and162being in courses that are knitted sequentially from the course containing the lowest backing loop number to the course containing the highest backing loop number. It may be seen that the wales and courses containing the backing loops158and160already have cut-pile loops110and sliver fiber tufts108respectively knitted therein. The knitting process shown inFIGS. 8 through 20shows the knitting of a new pile loop168into the wale and course containing the backing loop162as well as the knitting of a new backing loop172in a new course being knit above (and thereby in the same wale as) the backing loop162.

Note that in each ofFIGS. 8 through 20, the dial needle146is generally located inside the tubular cut-pile knit segment100with its distal end (the end with the hook148) extending from the interior of the tubular cut-pile knit segment100radially outwardly. Thus, movement of the dial needle146in a proximal direction is defined as movement radially inwardly with respect to the tubular cut-pile knit segment100, and movement of the dial needle146in a distal direction is defined as movement radially outwardly with respect to the tubular cut-pile knit segment100. The dial needle146is oriented such that the latch150pivots upwardly and the opening defined by the hook148is located above the tubular cut-pile knit segment146, and the movement of the dial needle146is radial with respect to the tubular cut-pile knit segment100. Those skilled in the art will at once appreciate that the location, orientation, and movement of the dial needle146is radically different from the location, orientation, and movement of needles in currently known circular pile knitting machines. (The needles in currently known circular pile knitting machines are oriented essentially parallel to the axis of the tubular segment being knit, with the hooks of the needles located above the top end of the tubular segment being knit.)

Note also that in each ofFIGS. 8 through 20, the cylinder needles152are located outside the tubular cut-pile knit segment100and are oriented in essentially parallel fashion to the longitudinal axis of the tubular cut-pile knit segment100with their distal ends (the ends with the hooks154) extending upwardly at locations near the top edge112of the tubular cut-pile knit segment100. Thus, movement of the cylinder needles152in a proximal direction is defined as movement upwardly with respect to the top edge112of the tubular cut-pile knit segment100, and movement of the cylinder needles152in a distal direction is defined as movement downwardly with respect to the top edge112of the tubular cut-pile knit segment100. The cylinder needles152are oriented such that the tapered cutting edge156and the opening defined by the hook154are located away from the tubular cut-pile knit segment100, and the movement of the cylinder needles152is up and down parallel to the longitudinal axis of the tubular cut-pile knit segment100. Those skilled in the art will at once appreciate that the location, orientation, and movement of the cylinder needles152is radically different from the location, orientation, and movement of needles in currently known circular pile knitting machines.

The knitting process that is schematically illustrated inFIGS. 8 through 20may be thought of as comprising three stages, as indicated by arcs I1, II1and III1, inFIG. 7. In the first stage of the knitting process, shown inFIGS. 8 through 15, a new pile loop is knitted into the tubular cut-pile knit segment100. During this first stage I1, both the dial needles146, and cylinder needles152are utilized to creating the new pile loop from pile yarn240. In the second stage II1of the knitting process, shown inFIGS. 13 through 18, a new backing loop is knitted into the tubular cut-pile knit segment100. During this second stage, only the dial needles152move in creating the new backing loops from backing yarn236, with the cylinder needles152remaining stationary. In the third stage III1of the knitting process, shown inFIGS. 19 and 20, the new pile loop110is cut to form a cut-pile loop110by the tapered cutting edges156of the cylinder needles152. During this third stage III1, only the cylinder needles152are utilized to cut the new pile loop110free from the pile yarn240, with the dial needle146remaining stationary.

As mentioned above, the first stage I1of the knitting process is shown inFIGS. 8 through 12. Referring first toFIG. 8, the dial needle146is shown in its fully proximal or resting position, with the backing loop162engaged by the hook148of the dial needle146(near the distal-most end of the dial needle146) and with the latch150in its closed position with the distal end of the latch150adjacent the distal end of the hook148. The cylinder needles152are each shown in their fully proximal or resting position.

Referring next toFIG. 9in contrast withFIG. 8, it may be seen that the dial needle146has moved in a distal direction, and the backing loop162has begun to open the latch150, causing the latch150to move to a position approximately midway between its closed and opened positions. Note that the backing loop162is adjacent the proximal end of the latch150. Simultaneously, the cylinder needles152have also begun to move in a distal (upward) direction.

Referring next toFIG. 10in contrast withFIG. 9, it may be seen that the dial needle146has continued to move in a distal direction to its tuck position, and the backing loop162is located nearly at the distal end of the latch150, causing the latch150to move to its opened position. The cylinder needles152have moved into their fully distal (upward) or tuck position, where their hooks154are located above the dial needle146(by approximately 5.0 mm to 8.0 mm). When the dial needle146and the cylinder needles152are in their respective tuck positions, pile yarn166(also referred to as “face yarn”) is inserted into the hook148of the dial needle146.

Referring next toFIG. 11in contrast withFIG. 10, it may be seen that the dial needle146has moved in a proximal direction, pulling the pile yarn166into contact with the cylinder needles152just below their respective the hooks154. As this occurs, the cylinder needles152begin to move downward, with the hooks154of the cylinder needles152drawing the pile yarn166downward on both sides of the dial needle146, thereby beginning to create a new pile loop168.

Referring next toFIG. 12in contrast withFIG. 11, it may be seen that the dial needle146has returned to its fully proximal or resting position, and the cylinder needles152have returned to their fully proximal or resting positions. Both the backing loop162and the new pile loop168are engaged by the hook148of the dial needle146(near the distal-most end of the dial needle146) and the latch150is in its closed position with the distal end of the latch150adjacent the distal end of the hook148. It should be noted that the length of the new pile loop168may be adjusted by raising or lowering the fully proximal or resting positions of the cylinder needles152. This completes the first stage of the knitting process, and is the starting point for the second stage of the knitting process, which is shown inFIGS. 13 through 18.

Referring first toFIG. 13in contrast withFIG. 12, it may be seen that the dial needle146has moved in a distal direction, and the backing loop162and the new pile loop168have begun to open the latch150, causing the latch150to move to a position approximately midway between its closed and opened positions. Note that the backing loop162and the new pile loop168are adjacent the proximal end of the latch150. The cylinder needles152remain in their fully proximal or resting position, as they will continue to do throughout the second stage of the knitting process.

Referring now toFIG. 14in contrast withFIG. 13, it may be seen that the dial needle146has continued to move in a distal direction, and the backing loop162and the new pile loop168are located nearly at the distal end of the latch150, causing the latch150to move to its opened position. In this position, the backing loop162and the new pile loop168are about to fall off of the latch150.

Referring next toFIG. 15in contrast withFIG. 14, the dial needle146has moved to its fully distal or clearing position. With the dial needle146in its fully distal position, the backing loop162and the new pile loop168have slipped entirely off of the latch150, and are located on the dial needle146in a position that is proximal to the latch150. With the dial needle146in its clearing position, backing yarn170is inserted into the hook148of the dial needle146.

Referring now toFIG. 16in contrast withFIG. 15, it may be seen that the dial needle146has begun to move in a proximal direction with the hook148of the dial needle146drawing the backing yarn170proximally (radially inwardly) with respect to the tubular segment100, thereby beginning to create a new backing loop172. As the dial needle146moves distally, the new pile loop168and the backing loop162have moved in a distal direction on the dial needle146and have engaged the latch150, causing it to move from its opened position toward its closed position (it is shown inFIG. 16as having moved slightly past its midway position).

Referring next toFIG. 17in contrast withFIG. 16, it may be seen that the dial needle146the new backing loop172of the backing yarn170still being located on the hook148of the dial needle146. As the dial needle146has continued to move distally, the new pile loop168and the backing loop162have moved in a distal direction on the dial needle146and have begun to slide over the latch150, which is now in its closed position. The fact that the latch150is closed also assists in retaining the new backing loop172of the backing yarn170on the hook148of the dial needle146.

Referring next toFIG. 18in contrast withFIG. 17, it may be seen that the dial needle146has moved to its fully proximal or resting direction, and has pulled the new backing loop172of the backing yarn170through the new pile loop168and the backing loop162. As this happened, the new pile loop168and the backing loop162slipped off of the latch150and over the hook148of the dial needle146; this is referred as the new pile loop168and the backing loop162having been “cast off” the dial needle146. Thus, the new backing loop172has been knitted through the new pile loop168and the backing loop162, thereby locking the new pile loop168into the tubular segment100. Thus, the tubular segment100is knitted with the new pile loop168extending outwardly. This completes the second stage II1of the knitting process, and is the starting point for the third stage III1of the knitting process, which is shown inFIGS. 19 and 20.

Referring first toFIG. 19in contrast withFIG. 18, it may be seen that a cylinder217is schematically illustrated with an upwardly facing top edge219. The top edge219of the cylinder217is located between the cylinder needles152and the tubular cut segment100(although it will be understood by those skilled in the art that the cylinder needles152are installed with their distal portions both mounted in and operated by the cylinder217). Located above the top edge219of the cylinder217is a yarn cutting roll250having an outer edge251that contacts the top edge219of the cylinder217to pinch the portions of the pile yarn166that will comprise the ends142,149of the new pile loop168therebetween. As this occurs, the cylinder needles152move in a distal (upward) direction such that their the tapered cutting edges156cut the new pile loop168free from the pile yarn166. (Note that the cutting roll250itself does not do any cutting; rather, it only holds the pile yarn166in place while the cylinder needles152move to cause the tapered cutting edges156to cut the pile yarn166.)

Referring finally toFIG. 20in contrast withFIG. 19, it may be seen that the new pile loop168is locked in place in the tubular cut-pile knit segment100by the new backing loop172, which has been knitted through the new pile loop168and the backing loop162. By reviewing the operation described inFIGS. 8 through 20, which occurs repeatedly, it may thus be appreciated that the tubular cut-pile knit segment100is knitted with its cut-pile segments110extending outwardly.

Those skilled in the art will appreciate that while the process shown inFIGS. 8 through 20has been depicted with only a single dial needle146and two cylinder needles152, a plurality of alternating dial needles146and cylinder needles152will be used, all located, oriented, and moving in a manner similar to that described with reference to the dial needle146and the cylinder needles152. In the preferred embodiment, between forty and one hundred of each of the dial needles146and the cylinder needles152will be used, with the currently preferred embodiment having approximately fifty of each of the dial needles146and the cylinder needles152. It will be appreciated by those skilled in the art that the number of wales produced by a circular knitting machine is the same as the number of dial needles146used by the circular knitting machine.

As shown inFIG. 5, by way of example of formation of courses including tufts of sliver fibers108, the construction of the portion of the tubular segment100in the area of the course132and the wale126will be discussed herein. The loop134formed in backing yarn segment136is located in this area, with a loop131formed in a yarn segment139being located in the course116below the loop134, and the loop130formed in a yarn segment132being located in the course120above the loop134. The loop134extends through the loop131from the outside to the inside of the tubular knit segment100(shown inFIG. 5), and the loop130also extends through the loop134from the outside to the inside. It will at once be appreciated by those skilled in the art that this arrangement of loops in sequentially knitted courses is completely opposite to the way in which sliver knit fabrics have been knitted on known circular knitting machines.

A tuft of pile fibers108having a loop portion109and opposite end portions111and113is knitted into the knit base material104together with the loop134. The loop portion109of that particular tuft of pile fibers108is located adjacent the top of the loop134, and the opposite end portions112and113of that particular tuft of pile fibers108extend outwardly from the interior of the loop134, above the loop131and below the loop130. In a similar manner, each of the other tufts of the pile fibers108is knitted into the knit base material104with a different loop.

FIGS. 21 through 27illustrate a sliver knitting process which may be used to knit the sliver fiber courses114,118and122of tubular sliver knit segment100shown inFIGS. 1 and 5. These figures show in sequential fashion how a stitch is formed by these steps I2, II2, III2(seeFIG. 7) in the sliver pile courses114,118and122. Each of these figures shows a dial146needle having a hook148located at the distal end thereof and a latch150that has a proximal end that is pivotally mounted at a location on the needle146that is proximal of the hook148. The latch150can pivot between a closed position (shown inFIGS. 21,26, and27) in which the distal end of the latch150contacts the end of the hook148to form an enclosed area with the hook148, and an opened position (shown inFIGS. 23 and 24) in which the distal end of the latch150forms a small acute angle with the proximal end of the needle146.FIGS. 22 and 25show the latch150in intermediate positions.

FIGS. 21 through 27also show the tubular knit segment100in phantom lines, with only several loops in a single wale being shown in solid lines. Specifically, sequential loops184,186, and188are shown in each ofFIGS. 21 through 27, with the loops184,186, and188being in courses that are knitted sequentially from the course containing the lowest loop number (184) to the course containing the highest loop number (188). The knitting process shown inFIGS. 21 through 27shows the knitting of a new loop190in a new course being knit above the loop188.

Note that in each ofFIGS. 21 through 27, the needle146is generally located inside the tubular knit segment100with its distal end (the end with the hook148) extending from the interior of the tubular knit segment100outwardly. Thus, movement of the needle146in a proximal direction is defined as movement radially inwardly with respect to the tubular knit segment100, and movement of the needle146in a distal direction is defined as movement radially outwardly with respect to the tubular knit segment100. Those skilled in the art will at once appreciate that the location, orientation, and movement of the needle146is radically different from the location, orientation, and movement of needles in currently known circular knitting machines. (The needles in currently known circular knitting machines are typically oriented essentially parallel to the axis of the tubular segment being knit, with the hooks of the needles located above the top end of the tubular segment being knit.)

Referring first toFIG. 21, the needle146is in its fully proximal or resting position, with the loop188engaged by the hook148of the needle146(near the distal-most end of the needle146) and with the latch150in its closed position with the distal end of the latch150adjacent the distal end of the hook148.

Referring next toFIG. 22in contrast withFIG. 21, it may be seen that the needle146has moved in a distal direction, and the loop188has opened the latch150and caused the latch150to move to a position approximately midway between its closed and opened positions. Note that the loop188is adjacent the proximal end of the latch150.

Referring now toFIG. 23in contrast withFIG. 22, it may be seen that the needle146has continued to move in a distal direction, and the loop188is located nearly at the distal end of the latch150with the latch150remaining in the opened position. In this position, the loop188is about to fall off of the latch159, although the loop188will remain on the needle146.

Referring next toFIG. 24, the circular knitting machine200of which the needle146is a part includes a doffer roll202having a wire face204. The doffer roll202is part of a doffer arrangement201of the exemplary embodiment of circular knitting machine200illustrated herein inFIGS. 6 and 7. Those skilled in the art will immediately appreciate that the location and orientation of the doffer roll202is also radically different from the location and orientation of doffer rolls in currently known circular knitting machines. (The doffer rolls in currently known circular knitting machines are located above the hooks of the needles, which needles, as mentioned above, are oriented parallel to the axis of the tubular segment being knit, with the hooks of the needles being located above the top end of the tubular segment being knit.)

The doffer roll202is rotating in a clockwise direction, and it carries sliver fibers206in the wire face202, the sliver fibers206being supplied from a sliver rope (not shown) being fed into the head (not shown) that contains the doffer roll202and the wire face204.

As indicated inFIG. 7, the courses having a pile made from sliver fibers are knitted in three steps I2, II2, III2, using only the dial needles146in cooperation with the doffer arrangement201and the second backing yarn feeding arrangement222. In general, the operations taking place in step I2are illustrated and described below in conjunction withFIGS. 23 and 24; the operations carried out in step II2are illustrated and described below in conjunction withFIGS. 25 and 26; and the operations carried out in step III2are illustrated and described below with regard toFIG. 27.

As shown inFIGS. 7 and 23, at the completion of the final step III1of the process used for knitting a course of cut-fiber pile, the dial needles146begin to move radially outward toward an extended position at which the hooks148of the dial needles will engage the wire face tool4of the doffer roll202, so that the hooks148may receive a tuff of pile fibers108from the wire face tool4of the doffer roll202.

As may be seen inFIG. 24in contrast withFIG. 23, the needle146has moved to its fully distal position, which places the hook148of the needle146into the wire face204of the doffer roll202. The rotation of the doffer roll202causes some of the sliver fibers206in the wire face204to become engaged by the hook148, forming a tuft of pile fibers108on the hook148. It may also be noted that with the needle146in its fully distal position, the loop188has slipped entirely off of the latch150, and is located on the needle146in a position that is proximal to the latch150. It is noted, however, that in the courses having a pile made from a yarn rather than sliver fibers, as described above, the needles146may only need to move outward to a “tuck” position, as shown inFIG. 23, to have the hook148receive the fiber which is cut to form the cut-fiber pile. Having the needles146move outward to only the tuck position provides more support for the needles146, and may provide a more robust design.

Referring now toFIG. 25in contrast withFIG. 24, it may be seen that the needle146has begun to move in a proximal direction with the tuft of the pile fibers108still being located on the hook148of the needle146. The hook148is now located away from the wire face204of the doffer roll202(not shown inFIG. 25), and the hook148has also engaged a backing yarn segment189and begun to form a new loop190of the backing fabric104. As the needle146has moved distally, the loop188has moved in a proximal direction on the needle146and has engaged the latch150, causing it to move from its opened position toward its closed position (it is shown inFIG. 25as having moved slightly past its midway position).

Referring next toFIG. 26in contrast withFIG. 25, it may be seen that the needle146has continued to move in a proximal direction, with both the tuft of the pile fibers108and the loop190of the backing yarn segment189still being located on the hook148of the needle146. As the needle146has continued to move distally, the loop188has moved in a proximal direction on the needle146and has begun to slide over the latch150, which is now in its closed position. The fact that the latch150is closed also assists in retaining both the tuft of the pile fibers108and the loop190of the yarn segment189on the hook148of the needle146.

Referring next toFIG. 27in contrast withFIG. 26, it may be seen that the needle146has moved nearly to its fully proximal or resting direction, and has pulled the new loop190of the backing yarn segment189and the loop of the new tuft of the pile fibers108through the loop188. As this happened, the loop188slipped off of the hook148and the latch150of the needle146. This is referred as the loop188having been “cast off” the needle146. Thus, the new loop190has been knitted through the loop188, with the new tuft of the pile fibers108having their midpoints adjacent the top of the loop190, and their ends extending outwardly from the tubular knit segment100. Thus, the tubular knit segment100is knitted with the sliver pile fibers108extending outwardly.

Those skilled in the art will appreciate that while the process shown inFIGS. 21 through 27has been depicted with only a single dial needle146, a plurality of needles may be used in practicing the invention, all located, oriented, and moving in a manner similar to that described with reference to the needle146. In various embodiments, for example, it is contemplated that between forty and one hundred needles may be used, with the exemplary embodiment100described herein having approximately fifty needles. It will be appreciated by those skilled in the art that the number of wales produced by a circular knitting machine is the same as the number of needles used by the circular knitting machine.

A wide variety of materials may be used to knit the backing104of the tubular knit segment100, and the pile of the tubular knit paint roller cover fabric of the present invention may be made of virtually any of the materials used in cut-pile knit fabrics in the past. For example, the backing and pile yarns or slivers may each be made of natural or synthetic yarn fibers, or a blend of natural and synthetic fibers in the yarn. Natural fibers used in the backing and pile face may be, for example, wool. Synthetic fibers used in the knit base may be, for example, polyester, acrylic, polypropylene, aramid, and spandex, or a blend of any of the aforementioned. Synthetic fiber yarns used in the pile face may be, for example, polyester, acrylic, nylon, modacrylic, rayon, polypropylene, and aramid, or a blend of any of the aforementioned. The backing yarn may optionally be made at least in part of a low melt material, such as the yarn used for the base in the above-incorporated by reference U.S. Pat. No. 6,766,668, to Sinykin. Yarn deniers for both the backing and pile face may be between approximately seventy-five and approximately one thousand five hundred, although yarns outside these ranges may be useable as well. The pile face may use yarns or slivers ranging from microdenier fibers to polyamide fibers.

Returning now toFIGS. 2 through 4, the installation of the tubular cut-pile knit segment100onto a paint roller cover core106is schematically illustrated. The installation method depicted inFIGS. 2 through 4is fully disclosed in copending U.S. patent application Ser. No. 12/100,050, filed on Apr. 9, 2008, entitled “Method of Manufacturing Paint Roller Covers From a Tubular Fabric Sleeve,” which patent application is assigned to the assignee of the present invention, and which patent application is hereby incorporated herein by reference in its entirety. Alternately, other installation methods can be used as well, including those disclosed in copending U.S. patent application Ser. No. 12/015,612, filed on Jan. 17, 2008, entitled “Method of Manufacturing Paint Roller Covers From a Tubular Fabric Sleeve,” which patent application is assigned to the assignee of the present invention, and which patent application is hereby incorporated herein by reference in its entirety.

It will be appreciated by those skilled in the art that the paint roller cover core106may constitute plastic tubular core stock that has been cut to single paint roller size (typically nine inches (229 millimeters)). (Alternately, it may be cut to a longer length, such as, for example, sixty-four inches (1625 millimeters); if such a longer length is used, following installation of the tubular cut-pile knit segment30onto the plastic tubular core stock, it may be cut into the desired size shorter paint roller covers, such as, for example, seven nine inch (229 millimeters) paint roller covers.) Finishing the paint roller covers typically will include the steps of combing the knit fabric having alternating courses of sliver fiber pile and cut-pile on the paint roller cover and shearing the knit fabric having alternating courses of sliver fiber pile and cut-pile to the desired length. These finishing steps may occur either before or after cutting longer segments to the desired length. Finally, the edges of the paint roller covers are beveled, and any loose yarn fibers may be vacuumed off.

Referring now toFIG. 2, the paint roller cover core106covered with a non-tacky adhesive105is illustrated. The tubular knit segment100is shown as it is about to be pulled onto the exterior surface of the paint roller cover core106. The tubular cut-pile knit segment100has an inner diameter that is approximately the same size as or slightly smaller than the outer diameter of the paint roller cover core106, which outer diameter is typically approximately one and five-eighths inches (41 millimeters) to one and three-quarters inches (44 millimeters) (the inner diameter of the core member106is approximately one and one-half inches (38 millimeters), although alternative sizes such as inner diameters of one and three-quarters inches (44 millimeters) and two inches (51 millimeters) could be used as well). The tubular knit segment100may be sized to require that it be stretched slightly when it is placed onto the paint roller cover core106in order to achieve the correct density and/or positioning. Alternately, the tubular knit segment100could also be slightly larger than the outer diameter of the paint roller cover core106onto which it is to be installed and shrunk slightly to closely fit the paint roller cover core106.

The tubular knit segment100is of a length that corresponds to the length of the paint roller cover core106. For purposes of the example discussed herein, it will be assumed that the paint roller cover core106is approximately nine inches (229 millimeters) long and that the tubular knit segment100is approximately nine to nine and one-quarter inches (235 millimeters) long, which are lengths that are selected to allow the paint roller cover core106and the tubular knit segment100to be used for the manufacture of a single nine inch (229 millimeter) long paint roller cover. It will be appreciated by those skilled in the art that the paint roller cover core106and the tubular knit segment100could alternately be sized for use in manufacturing a plurality of paint roller covers of any of several different lengths. For example, the paint roller cover core106and the tubular knit segment100could each be approximately sixty-four inches (1625 millimeters) long, which is a sufficient length to allow them to be used for the manufacture of seven nine inch (229 millimeter) long paint roller covers107.

Since inner diameter of the tubular knit segment100is approximately the same as the paint roller cover core106, the tubular knit segment100need not be capable of substantial stretching when it is pulled onto the paint roller cover core106. The tubular knit segment100having outwardly extending pile made from alternating courses of sliver fibers tufts and cut-fibers, as taught herein, is resilient and will closely fit the outer diameter of the paint roller cover core106.

InFIG. 2, the tubular knit segment100is shown about to be pulled over the paint roller cover core106.FIG. 3shows the tubular knit segment100partly pulled onto the paint roller cover core106, andFIG. 4shows the tubular knit segment100fully pulled onto the paint roller cover core106. The tubular knit segment100is subsequently adhesively secured to the paint roller cover core106by the application of heat to cause the non-tacky adhesive105melt, thereby adhering the tubular cut-pile knit segment100the paint roller cover core106, as fully described in U.S. patent application Ser. No. 12/100,050, filed on Apr. 9, 2008.

Finishing the paint roller covers107will include the steps of combing the pile on the paint roller cover107and shearing the knit fabric having alternating courses of sliver fiber pile and cut-pile to the desired length. Finally, the edges of the paint roller covers107are beveled, and any loose yarn fibers may be vacuumed off.

It may therefore be appreciated from the above detailed description of the preferred embodiment of the present invention that it provides a tubular knit paint roller cover fabric having outwardly extending pile made of alternating courses of sliver fibers and cut-pile fibers that is suitable for use in the manufacture of a paint roller cover. The tubular knit paint roller cover fabric of the present invention is manufactured with the pile side facing outwardly rather than inwardly, thereby obviating the need to invert it prior to mounting it on a paint roller cover core. The tubular knit paint roller cover fabric of the present invention is of a size suitable for mounting on a paint roller cover core in a seamless manner, without cutting it except for cutting it to a length fitting the length of paint roller cover core material on which the tubular knit paint roller cover fabric is to be mounted.

The tubular knit paint roller cover fabric of the present invention, having outwardly extending pile made of alternating courses of sliver fibers and cut-pile fibers, is well suitable for use in its application on a paint roller cover, and will not experience any significant degradation of the tubular knit paint roller cover fabric due to its contact with a wide variety of paints, enamels, stains, etc. The tubular knit paint roller cover fabric of the present invention is manufactured in a manner in which the pile loops are securely retained by the knit base material such that the shedding of pile fibers from the tubular knit paint roller cover fabric is minimized. The tubular knit paint roller cover fabric of the present invention is also manufacturable in extended length segments that may later be cut to tubular segments of any desired length.

The tubular knit paint roller cover fabric of the present invention, having outwardly extending pile made of alternating courses of sliver fibers and cut-pile fibers, is of a construction which is both durable and long lasting when it has been secured to a paint roller cover core, and the resulting paint roller cover will provide the user with an acceptably long lifetime. The tubular knit paint roller cover fabric of the present invention is also inexpensive to manufacture, thereby enhancing its market appeal and to affording it the broadest possible market. Finally, all of the aforesaid advantages and objectives of the tubular knit paint roller cover fabric of the present invention are achieved without incurring any substantial relative disadvantage.

Although the foregoing description of the tubular knit paint roller cover of the present invention, having outwardly extending pile made of alternating courses of sliver fibers and cut-pile fibers, has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. It will be apparent to those having ordinary skill in the art that a number of changes, modifications, variations, or alterations to the invention as described herein may be made, none of which depart from the spirit or scope of the present invention. The particular embodiments and applications were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such changes, modifications, variations, and alterations should therefore be seen as being within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.