US3153271A

US3153271A - Yarn crimping apparatus

Info

Publication number: US3153271A
Application number: US240681A
Authority: US
Inventors: Eshuis Jannes
Original assignee: American Enka Corp
Current assignee: Akzona Inc
Priority date: 1961-12-05
Filing date: 1962-11-28
Publication date: 1964-10-20
Anticipated expiration: 1981-10-20
Also published as: NL272189A; BE624742A; ES282845A1; DE1435600A1; GB950575A

Description

Oct. 20, 1964 J. ESHUIS YARN CRIMPING APPARATUS Filed NOV. 28, 1962 INVENTOR.

JANNES ESHUIS BY 2 w I:

ATTO RN EY United States Patent 3,153,271 YARN CRIMIENG APPARATUS llannes Eshuis, Arnhem, Netherlands, assignor to American Eulra orporation, Erika, Nil a corporation of Delaware Filed Nov. 28, 1962., Ser. No. 249,631 Claims priority, application Netherlands 13cc. 5, 1%]. 3 @Clainrs. (ill. 281) This invention relates generally to crimping continuous filament yarns and tow and more particularly to a device for use in connection with stutter-box crimping apparatus which greatly facilitates starting-up of the process.

In general, apparatus for crimping filament yarns by the stutfer box method comprises two feed rollers and a crimping tube. The feed rollers are provided with smooth cylindrical surfaces and the crimping tube is shaped such that it forms a chamber which is closed at one end by parts of these surfaces of the feed rollers. At its opposite end the chamber is open or alternately may be closed by spring-loaded valves or the like. Also, such apparatus very often has additional means for heating, cooling, moistening, or finishing the yarns to be crimped to improve the performance thereof.

During normal operation, the yarn is fed to the nip of the feed rollers which feed the yarn into the crimping tube against the pressure of a yarn wad. Of course, when the process begins, the crimping tube does not yet contain such a yarn wad and in order to form the yarn into a wad, it is sometimes the practice to insert a counter-pressure rod in the tube. Usually the rod is held by hand. Although it is possible to get the process started in this manner, certain disadvantages result. For example, in many cases the yarn becomes entangled between the feed rollers and the crimping tube, causing yarn breakage in addition to clogging the apparatus. Such entanglement apparently results because of a gap between the crimping tube and feed rollers. Although the tube and rollers are positioned so that the space inside the crimping tube is closed at one end, there is still some play between these parts. This play must be maintained for various reasons. Thus, it is necessary for the rollers to move apart under spring tension in order to allow the passage of a thick piece of yarn, a crossing of filaments, or a knot. This freedom of movement must not be impeded by the rollers being in contact with the crimping tube. Moreover, the rollers must be able to rotate freely relative to the crimping tube, both when the apparatus is cold and when it heats and expands under operating conditions.

Both requirements make it necessary for a narrow slit 0 to be maintained between the circumferential surfaces of the rollers and the crimping tube. During normal operation, these slits do not cause any difficulties. The yarn wad is so coherent that filaments are not withdrawn by the feed rollers and pushed through the slits. Nor is it possible for the uncrimped yarn to pass through the slits since it is stopped by the yarn wad. However, when the process is first started, there is no yarn wad present to prevent the uncrimped yarn from passing through the slits and much of the time the counter-pressure rod does not prevent this from occurring. Under such circumstances, the feed rollers transport the yarn or filaments through one of the slits, resulting in the aforementioned yarn breakage and clogging of the apparatus.

Accordingly, it is an object of this invention to provide an apparatus for crimping yarn not having the inherent disadvantages of known crimping devices.

Another object of this invention is to provide a method for preventing yarn breakage and clogging during the starting-up operation of stuffer-box crimping apparatus.

Still another object of this invention is to provide stufferbox crimping apparatus in which yarn breakage and clogice ging caused by passage of the yarn between the feed rollers and crimping tube is prevented.

A further object is to provide apparatus for preventing passage of yarn through the slit formed between the feed rollers and crimping tube of conventional staffer-box crimping apparatus while minimizing wear of the rollers.

These and other objects will become apparent from the following detailed description.

In accordance with the present invention, the slit between the circumferential surfaces of the feed rollers and crimping tube of a conventional stutter-box crimping apparatus is blocked by a resilient device during the startingup operation. The device is composed of a material softer than the rollers, but sufficiently rigid, so that it will not bend away or be pushed aside by the rollers. With such a device, the yarn cannot pass through the slit and thus entanglement around the rollers is prevented.

An additional advantage is that the slit can be closed on the outside of the crimping tube. It might be expected that the yarn in this case would still enter the slit between the circumferential surface of a roller and the crimping tube. Surprisingly, this in itself does not cause any difficulties as long as the yarn is prevented from passing through the slit. In accordance with this invention, it has been found that the slit can be blocked effectively by placing a resilient closing device in front of the slit and on the outside of the crimping tube. Obviously, from a practical point of view, it is better to provide an apparatus in which the closing device can be placed on the outside of the crimping tube rather than one in which the slit must be blocked on the inside of the tube.

After the yarn wad has formed, the closing device can be moved away from the slit. Because of this, and the fact that the device is made of a softer material than the rollers, wear of the rollers is prevented. The closing device is slidably mounted on the outside of the crimping tube and is movable as far as the circumferential surfaces of the rollers.

Although the closing device may be constructed as a solid jacket and from a great variety of materials, it has been found simpler and preferable to make the device from a textile material such as a woven, knitted or braided fabric. Fabrics of linear polyamide filament yarns has been found especially suitable. It has even been found satisfactory to block the slits by means of a piece of multifilament tow, for example, a piece of polyamide or polyester tow, knotted in a ring around the crimping tube.

For purposes of illustration and not by way of limitation, the following detailed description of a preferred embodiment of the invention is given taken in conjunction with the accompanying drawing, wherein the figure shows a vertical view in section of a crimping apparatus in which the closing device is positioned as at the start of the operation.

In the figure, a part of the crimping tube 1 is shown in cross section in the plane of feed rollers 2 and 3. At the bottom end of crimping tube ll, its shape is such that it is almost closed by feed rollers 2 and 3. Feed rollers 2 and 3 are rotated by

shafts

4 and 5 in the directions indicated by the arrows. The rollers are pressed together by a spring tension device (not shown), so that yarn 6 is stuffed against yarn wad 7. Counter-pressure is exerted on yarn wad 7 by steel balls 8, the number of which varies depending upon the pressure required in the yarn wad.

Between crimping tube 1 and rollers 2 and 3 are two slits l0 and 11. With the apparatus of the prior art, yarn 6 can pass through these slits during the starting operation. Not until a reasonably thick yarn wad is formed does this risk cease to exist. In the drawing a partly formed yarn wad 7 is shown. Yarn end 12 leaves the wad 7 at the upper side thereof and passes through the layer of balls 8, after which it emerges from the crimping tube 1. In order to prevent the yarn from being pushed through slits and 11, a ring 9 of a synthetic material, such as a fabric woven of polyamide filaments, is movably mounted around the outside of the crimping tube. While a polyamide ring is specifically mentioned, other synthetic materials are also very suitable. The underside of the ring 9 is so shaped that it fits accurately against the circumferential surfaces of rollers 2 and 3.

When the apparatus is started, ring 9 is slid downwardly against the surfaces of rollers 2 and 3. The yarn 6 is then threaded between the rollers 2 and 3, through tube 1, and its free end 12 passed to a winding device. Thereafter, rollers 2 and 3 are put into operation. After a sufliciently thick wad of yarn has formed, the winding device is placed in operation. While yarn wad 7 is being formed, ring 9 is held in pressure contact with the rollers 2 and 3 either by hand or by means of a suitable device (not shown). After a sufi'lcient wad is formed, the ring 6 is raised somewhat, so that it is no longer in contact with rollers 2 and 3.

From the foregoing, it can readily be seen that the method and apparatus of this invention prevents yarn 6 from passing through slits 10 and 11. The apparatus eliminates yarn breakage and clogging of the apparatus and results in a stutter-box crimping operation that is more reliable and may be combined more satisfactorily with other treatments, particularly those involving the stretching or drawing of synthetic yarns.

Many alterations, modifications and embodiments within the scope of this invention will be apparent to those skilled in the art without departing from the spirit and scope thereof. It is therefore intended that the invention only be limited to the extent set forth in the following claims.

What is claimed is:

1. In a stutter-box crimping apparatus having feed rollers and a crimping tube positioned directly adjacent thereto whereby slits are formed between said tube and the circumferential surfaces of said rollers, the improvement comprising a fabric sleeve slidably mounted around the outer surface of said crimping tube whereby the sleeve may be moved to a position blocking said slits and preventing yarn from passing therethrough during start up of the apparatus.

2. In a stuffer box crimping apparatus having feed rollers and a crimping tube positioned directly adjacent thereto whereby slits are formed between said tube and the circumferential surfaces of said rollers, the improvement comprising a resilient sleeve slidably mounted around the outer surface of said crimping tube, said sleeve consisting of a material softer than the rollers but sufficiently rigid so that it will not bend away or be pushed aside by the rollers, whereby the sleeve may be moved to a position blocking said slits thus preventing yarn from passing therethrough during start up of the apparatus.

3. The apparatus of claim 2 in which the sleeve consists of a piece of rnulti-filament tow knotted in a ring around the crimping tube.

References Cited in the file of this patent UNITED STATES PATENTS 407,391 Ackroyd et al. July 23, 1889 2,152,295 Weinberger Mar. 28, 1939 2,695,429 Howes et al. Nov. 30, 1954 2,949,659 Heijins et a1 Aug. 23, 1960 3,035,313 Naegeli et al May 22, 1962 FOREIGN PATENTS 883,119 Great Britain Nov. 22, 1961

Claims

1. IN A STUFFER-BOX CRIMPING APPARATUS HAVING FEED ROLLERS AND A CRIMPING TUBE POSITIONED DIRECTLY ADJACENT THERETO WHEREBY SLITS ARE FORMED BETWEEN SAID TUBE AND THE CIRCUMFERENTIAL SURFACES OF SAID ROLLERS, THE IMPROVEMENT COMPRISING A FABRIC SLEEVE SLIDABLY MOUNTED AROUNG THE OUTER SURFACE OF SAID CRIMPING TUBE WHEREBY THE SLEEVE MAY BE MOVED TO A POSITION BLOCKING SAID SLITS AND PREVENTING YARN FROM PASSING THERETHROUGH DURING START UP OF THE APPARTUS.