US3246378A - Napping machine - Google Patents

Description

G. BECKERS A ril 19, 1966 NAPPING MACHINE 3 Sheets-Sheet 1 Filed Aug. 25 1963 INVENTOR GUSTAV BEG/(EH8 A ril 19, .1966

Filed Aug.

RPM'S G. BECKERS NAPPING MACHINE 5 Sheets-Sheet 2 INVENTOR GUSTAV BEG/(5R5 April 19, 1966 G. BECKERS 3,246,378

NAPPING MACHINE Filed Aug. 23, 1963 3 Sheets-Sheet 5 INVENTOR GUSTAV EEC/(E175 United States Patent lice 3,246,378 NAPPING MACHINE Gustav Becker's, Rheydt, Germany, assignor to A. Monforts Maschinenfahrik, Monchen-Gladbach, Germany Filed Aug. 23, 1963, Ser. No. 303,997 Claims priority, applicatiglgl 7G6e2rmany, Nov. 27, 1958,

3 6 Claims. (Cl. 2631) This application is a continuation-in-part of application Serial No. 854,767 filed November 23, 1959.

This invention relates to a napping machine and, more particularly, to such machine wherein napping rollers thereof are fitted with rows of needles especially designed to handle fabrics requiring gentle treatment.

The napping rollers or cylinders now in use consist of a roller with a lamina or sheet of material, carrying projecting napping needles, wrapped around the roller. The napping needles are U-shaped wires having points angled and ground to a sharp point fixed reciprocably in the sheet of material. Such napping needles bend elas tically when pressed down singly. As a whole, however, the napping cover must be regarded as being rigid since to deflect a single napping needle point by but 0.2 millimeter, measured at the point of the needle, a transverse force of grams is required when normal napping needles are being used. The tensile strength oftextile fibres to be napped amounts to but 2 to 10 grams for W001, or 4 to 6 grams for cotton and diverse synthetic fibres. Before the elasticity of the napping needles can become effective, therefore, the fibres are torn. Damage to the fabrics due to the excessive strength of the napping cover cannot be avoided since the points of the napping needles cannot move rearwardly and radially inwardly.

The present invention provides a novel napping method and a novel napping roller. The napping needles are not rigidly mounted as in the known devices, but are secured to the roller so as to be easily or freely deflected. Easily deflected denotes that the napping needles each give way to a transverse stress less than the tensile strength of the textile fibre ends to be teased from a fabric during napping, i.e. the napping roller of this invention affects the fabric to be napped much more gently than former napping roller-s. The force required to deflect the needles of the present invention is dependent, at least to a degree, on the speed of rotation of the roller. The needles in the napping roller are deflected rather than bent so that the stress placed on theminute fibers of the yarns may be regulated to a stress less than the breaking strength of the fibre-s.

The napping rollers of the present invention have rows of napping needles generally of a greater length and of a much lower density of needles than rollers conventionally used heretofore. The length of each needle is at least millimeters, measured for elastically seated needles from the base layer to the tip of the needle, and for pivotally mounted needles from the axis of the pivot to the tip of the needle. The distance of the tips of the needles from one another, in the direction of rotation of the napping roller (circumferentia'lly), is also at least 20 millimeters. Single needles are preferably used, but U- shaped napping needles fixed in their middle part to the core of the napping roller may also be used. It is of importance to the design of the napping roller according to the present invention that the force of the needles into the fabric to be worked is accurately determinable.

The drawings show the napping rollers of the present invention, in which:

FIG. 1 is a cross section of a napping roller with individual needles elastically seated.

FIG. 2 shows a cross section of a napping roller with pivotally mounted individual needles.

3,246,378 Patented Apr. 19, 1966 FIGS. 3 and 4 show on an enlarged scale, in cross section, two different napping needle arrangements for pivoted needles.

FIG. 5 shows a napping roller with needle settings of a varied compactness and a mounting for such needles.

FIG. 5a is an enlarged fragmentary section taken at Sa-Sa of FIG. 2.

FIG. 6 is a diagrammatic showing of what is meant by the stress for deflection of the needles being measurable in grams.

FIG. 7 is a graphical representation of the stress expressed in grams required to deflect a needle as a function of the rpm. of the napping rollers.

FIG. 8 is a diagrammatic showing of a conventional napping machine in which the napping rollers of the present invention may be used, and

FIG. 9 is a diagrammatic view showing the action of the needles on a textile web.

The easily deflectable napping needles of this invention may be flexibly or pivotally attached to the core of the napping roller or to pivots mounted about a central shaft means. The napping needles may be fixed in a soft elastic covering of. the napping roller core, as seen in FIG. 1, but the elastic cover according to the present invention is chosen in such a way that the napping needles will be deflected by a stress below the tensile strength of the textile fibres, i.e. the napping needles act only up to a tranverse force of a very few grams, but not in excess of 10 grams, acting tangentially upon the circumference of the napping roller. Upon this or any stronger transverse stress the needles are deflected in the opposite direction to the direction of rotation of the needles points and so slide over the surface of the texture without breaking the fibres. As will be seen from FIG- URE 9, the points of the needles move radially inwardly under a stress still below the breaking stress of the filament from which the textile yarns are spun.

In FIG. 1, a napping roller core is shown at a with an elastic layer b for fixing the needles to the core and a soft elastic bedding d to resiliently suport napping needles 0. The layer b and the bedding d are chosen in such a way that the napping needles c will deflect so as to lie down against the rotating napping roller under the influence of a force on the end of the needle weaker than the tensile strength of the textile fibres to be worked. A wire mesh b' may be used between bedding layers b and d. The length andspacing for such needles is preferably the same as that for single needles described above.

For the arrangement of the napping needles, pivots arranged parallel to the axis of the roller may be used, as seen in FIG. 2. Pivots f are positioned around the napping roller and napping needles fitted with pivoting eyelets, as shown in FIG. 3 or 4, are strung on each pivot. These needles may be spaced evenly over the entire length of the napping roller or they may be variously spaced along the roller, or they can be omitted altogether in parts. While the force that the napping needles impinging on the textile to be worked exerts on the fibres of the textile is determined, in the case of the elastic mounting, to a great extent by the elasticity of the soft bedding of the napping needles, the force exerted by pivoted needles on the fibres depends upon the centrifugal force of the needles, i.e. it depends upon the number of revolutions per minute of the napping roller. A 20 mm. length of needle is preferred.

In the preferred use of the present invention the spac ing about the circumference of the pivots for the napping needles should be such that the points of the napping needles on successive pivots are separated by approximately one needle length. The distance between needles in the axial direction on the pivots may be varied to form a pattern in the trap of the fabrics. The essential new result of the invention, however, is that the filaments of the yarns of the fabrics are not ruptured.

In order to present outward bending of the pivots that are arranged concentrically around the napping roller core caused by centrifugal force (such pivots should be very thin to enable them to fully meet their task), holding devices for the elongated pivots may be provided at intervals along the roller which are preferably discs or stars mounted on the napping roller core and forming spaced bearings or supports for the pivots.

In FIG. 2 a number of pivots f are provided for the napping needles between holding devices e. Several such pivots f are arranged concentrically about the napping roller with their axes parallel to the napping roller.

FIG. 3 shows the lower end of a needle c' bent around the pivot f and separated by shims g from an adjacent needle.

FIG. 4 shows a mounting for the napping needles 0' by special grommets 2' connected to the needles for seating on the pivots.

FIG. 5 shows how the napping needle arrangement 0 may vary along the width of the napping roller a. Needles may be omitted altogether in certain portions of the roller.

The drawings further show, in FIG. 50, that the pivots f can be and preferably are subdivided at plates e where the plates operating as holding devices are positioned by providing extensions f on one pivot section 1 that extends through a hole in plate e and is received in a bore 1 of a second pivot f.

The principal advantage of the present invention is that the penetrating force of the napping needles into the fabric material to be worked may be selected. Heretofore, the napping method could only be manipulated satisfactorily by very experienced specialists because the penetrating force was not known, had never been taken into account, and could not be changed. The present invention has been worked out after very careful tests had been made during napping with special care being paid to the action of each individual napping needle. Both principal kinds of napping needles according to the present invention, the elastically and the pivotally mounted, are non-destructive to a very high degree since they act only below the tensile strength of the textile fibres. Moreover, each napping needle participates in the napping process each time it comes in contact with the fabric, while only about every fiftieth needle took effect in the napping methods carried out heretofore. This was shown during the tests mentioned above. Piercing of yarns and fibres is precluded by the napping rollers of the present invention, since the napping needles will only detach such fibre ends as can be done without breaking the fibre.

The novel napping method is applicable to a great variety of woven, non-woven and knitted fabrics. The thickness of the texture can be taken into account by the adjustability of the napping rollers in the machine by the eccentric bearing boxes which are conventional. The napping effect can also be widely adapted to the various types of weaves of the texture, in the case of the elastically seated napping needles by exchange of the napping roller or, with pivotally mounted needles by altering the number of revolutions per minute of the napping roller and thereby the centrifugal force of the napping needles.

FIGURE 9 diagrammatically shows the napping roller rotating clockwise. A Web of cloth or fabric K is passing in the direction of the arrow, but at a lower speed than the circumferential speed of the'napping roller, through the napping machine and over the napping roller. Needles c, 0 c 0 are four successive needles, each mounted to pivot about a. point 7, f f f as the case may be. Needle c has not as yet impinged on the cloth.

The point of needle c just touches the cloth K and then penetrates into it. The needle is swung back or deflected in the amount x by the resistance of the cloth which moves more slowly, with the point of the needle moving in an involute which deflects inwardly in the radial direction in the amount y. The resistance to deflection of the needle in the cloth K is so slight that no fibre of the cloth is torn out but that, rather, the needle moves back or gives way.

The point of the needle 0 has just disengaged the cloth K but still hangs on a fiber loop z, from which it slips out during the forward movement. The loop z pulls back again into the cloth because of its own elasticity and because its two ends are held in the cloth K. A loose fibre end, however, will be pulled out of the cloth and remain outside the underside of the cloth. As soon as the point of needle 0 has slipped out from the fiber loop z and has separated from the cloth K, it swings back to its normal position 0 immediately, because of the centrifugal force, in the amounts x and y into the position which corresponds to the position of the needle 0.

It can be seen that the needles c and c will move rearward as seen at x and radially inwardly as seen at y. It follows, then, that while the point of a needle 0 can, and will, penetrate the web K, it will automatically swing rearwardly and radially inwardly to Withdraw from the textile web, while picking the fibres of the web to cause a teasing or napping action. The needles cannot rupture the fibres, but can only pull loose ends of fibres out of the web to form the nap, so that the structural strength of the web is retained.

While the above explanation is given in connection with a napping roller similar to FIG. 2, it is evident that the needles of the FIG. 1 napping roller pivot about an axis similar to axis 1, and the needle points in the roller of FIG. 1 will perform in the same manner as the needles of FIG. 2.

A further advantage of the napping rollers of the present invention is that a variety of effects can be obtained by napping under the method of the invention. The napping rollers as shown in FIG. 5 may result in nap stripes being formed when napping needles are arranged differently spaced along the rollers, or if they are omitted in parts altogether.

:FIG. 6 shows diagrammatically 1a napping roller having at least one needle 0 mounted on pivot f. This naping roller is rotating clockwise about axis 0. A force measuring device, shown diagrammatically as lever 10, pivoted at 11, is placed so that needle c strikes it. Movement of lever 10 is resisted by a spring 12 which may be appropriately loaded. If the needle 0 strikes lever 10 with suflicient force, the lever 10 will move; it, however, the needle c cannot exert sufficient force against lever 10, then needle 0 is deflected and lever it! does not move.

A typical graph of stress required to deflect the needles 0, plotted against the rpm. of the napping rollers, is shown in FIG. 7. It is clear, then, that the stress required to deflect the needles may be accurately adjusted to match the rupture stress of the fibres of the yarns of the specific piece of cloth being treated.

FIG. 8 shows a napping machine of conventional design in which the napping roller of the present invention may be used at R. The napping rollers of the present invention, of course, may be used in any other type of napping machine as, for instance, the mach-inc of U.S. Patent No. 484,700.

In practicing the napping method, the fibre strength of all kinds of fibres is known and, in the case of newly discovered synthetic fibres, the manufacturer can supply the data. By consulting the graph of FIG. 7, an rpm. is selected to give a force at the tip of needles 0 of less than the force that would break the fibres. The machine is then set to rotate the napping rollers at that speed, and the cloth is passed through the machine over the rollers.

By this method the texture of the cloth is not destroyed, but ends of the fibres of the yarns of which the cloth is made are pulled out and form a nap.

What is claimed is:

1. In a napping machine, a nap-ping roller including a core element, radially extending members secured to said core and spaced therealong at predetermined distances, a plurality of shafts extending parallel to the axis of said core and secured in said members, each said shaft having a plurality of napping needles loosely pivoted thereon, said shafts being spaced circumferentially about the core such that the spacing of the needle points about the circumference of the roller is substantially the same as the length of said needles, and means to rotate said napping roller at a selected speed when it is in use so that the resistance to deflection of each needle is less than 10 grams.

2. A napping roller for use in a napping machine of the type where the periphery of the roller is rotated at a predetermined speed against a web of textile to be mapped, said napping roller having an axis of rotation and a pcriphery, radially extending members secured to said roller and spaced therealong at predetermined distances, a plurality of needle mounting shafts secured in said members located at points radially outwardly and circumferentially of said axis of rotation, a plurality of napping needles pivotally mounted on each of said shafts, and each needle extending from its mounting in a generally radial outward direction and terminating in a point to determine the locus of the periphery of said nap-ping roller, the said periphery of said nap-ping roller being the cylinder described by the points of said napping needles when in use, each said needle being pivotable under a substantially constant force of less than ten grams when rotated at a predetermined speed, and through an are such that the point of said needle rnoves rearwardly, and moves radially inwardly.

3. The device of claim 1, including shim plates separating the needles from each other along each shaft.

4. The device of claim 1, including eyelets secured to the ends of said needles pivotally mounting said needles on said shafts.

5, The device of claim 1, wherein each said shaft comprises a plurality of adjacent parts, and means for connecting adjacent shaft parts comprising a pin on one of said parts and a socket on the other of said parts.

6. The device of claim 5, wherein the number of needles per unit length of adjacent shaft parts varies.

References Cited by the Examiner UNITED STATES PATENTS 111,086 1/1871 Reilly 15200 484,700 10/ 1892 Burr et al. 26--32 661,650 11/1900 Thurston.

753,970 3/1904 Foster 26-31 1,153,738 9/1915 Devoorde. 2,340,069 1/ 1944 McCarthy et a1. 26-29 2,466,348 4/ 1949 Ambye 2631 FOREIGN PATENTS 233,718 10/ 1924 Great Britain. 101,887 10/ 1923 Switzerland.

DONALD W. PARKER, Primary Examiner.

R. MACKEY, Assistant Examiner.

Claims (1)

1. IN A NAPPING MACHINE, A NAPPING ROLLER INCLUDING A CORE ELEMENT, RADIALLY EXTENDING MEMBERS SECURED TO SAID CORE AND SPACED THEREALONG AT PREDETERMINED DISTANCES, A PLURALITY OF SHAFTS EXTENDING PARALLEL TO THE AXIS OF SAID CORE AND SECURED IN SAID MEMBERS, EACH SAID SHAFT HAVING A PLURALITY OF NAPPING NEEDLES LOOSELY PIVOTED THEREON, SAID SHAFTS BEING SPACED CIRCUMFERENTIALLY ABOUT THE CORE SUCH THAT THE SPACING OF THE NEEDLE POINTS ABOUT THE CIRCUMFERENCE OF THE ROLLER IS SUBSTANTIALLY THE SAME AS THE LENGTH OF SAID NEEDLES, AND MEANS TO ROTATE SAID NAPPING ROLLER AT A SELECTED SPEED WHEN IT IS IN USE SO THAT THE RESISTANCE TO DEFLECTION OF EACH NEEDLE IS LESS THAN 10 GRAMS.

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