US3870242A

US3870242A - Yarn retarding device

Info

Publication number: US3870242A
Application number: US463099A
Authority: US
Inventors: Edward W Schussel
Original assignee: Wesco Industries Corp
Current assignee: IRO Inc; Wesco Industries Corp
Priority date: 1974-04-22
Filing date: 1974-04-22
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11
Also published as: DE2456440A1; DE2456440B2; GB1438437A

Abstract

A retarding device surrounding a storage drum adapted to have yarn wound tangentially thereon and unwound axially therefrom. The retarding device comprises a coiled spring whose opposite ends are secured to form a continuous retarding ring having an inner contour smaller than the outer contour of the drum before the ring is mounted on the drum whereby the ring is placed under tension when mounted on the drum. Each coil of the spring has a curved portion in bearing engagement against the drum which defines a constant resistance to the yarn which passes thereunder as it is axially withdrawn from the drum.

Description

United States Patent [1 1 Schussel 51 Mar. 11, 1975 I 1 YARN RETARDING DEVICE [73] Assignee: Wesco Industries, Corporation,

Plainview, N.Y.

221 Filed: Apr. 22, 1974 [21] Appl. No.: 463,099

52 us. Cl 242/47.01, 242/47.12, 242/147 R 511 int. Cl B65h 51/20 581 Field of Search 24214101 4713, 147 R,

3,702,176 11/1972 Rosen 242/47.01 3,713,307 l/1973 Muhlhausler 242/47.01 X 3,780,958 12/1973 Deniega et a1 242/47.12

Primary Examiner-Stanley N. Gilreath Attorney, Agent, or Firml-lenry R. Lerner [57] ABSTRACT A retarding device surrounding a storage drum adapted to have yarn wound tangentially thereon and unwound axially therefrom. The retarding device comprises a coiled spring whose opposite ends are secured to form a continuous retarding ring having an inner contour smaller than the outer contour of the drum before the ring is mounted on the drum whereby the ring is placed under tension when mounted on the drum. Each coil of the spring has a curved portion in bearing engagement against the drum which defines a constant resistance to the yarn which passes thereunder as it is axially withdrawn from the drum.

4 Claims, 3 Drawing Figures YARN RETARDING DEVICE BACKGROUND OF THE INVENTION The present invention relates to means for controlling the axial withdrawal of yarn or filament which has been wound about a drum or bobbin.

The invention has particular application to yarn storage and feeding devices, such as shown in U.S. Pat. Nos. 3,225,446, 3,419,225 and 3,780,958, the last mentioned patent being assigned to the assignee hereof. Each of the storage devices shown in the aforementioned patents includes a storage drum about which yarn is wound tangentially either by rotation of the drum or rotation of a winding element about the drum to form on the drum a number of windings which are stored for subsequent axial withdrawal as demanded by the textile producing machine.

It is highly desirable to control the tension of the yarn being withdrawn from the storage drum by using a retarding element which engages the yarn as it is withdrawn endwise of the drum. In U.S. Pat. No. 3,225,446, the retarding means comprises an ordinary resilient band placed about the drum so that the yarn which is withdrawn passes between the resilient band and the drum and has imparted thereto a retarding force. Such arrangement is not very satisfactory because the tension of the yarn being withdrawn cannot be accurately controlled and because variations in tension do occur causing a lack of uniformity in the article produced by the textile machine.

Another form of retarding element which avoids the problems inherent in the use of a conventional resilient band is that shown in U.S. Pat. Nos. 3,648,939 and 3,702,176 wherein the retarding element comprises a plurality of flexible elements formed by resilient fingers which are inclined inwardly from a base ring along an imaginary conical surface and extend in the direction of relative rotation of the yarn during its withdrawal from the drum. The outerends of the resilient fingers are secured to a base ring which is greater in diameter than the portion of the drum it surrounds, and the inner ends of these fingers, which may be curved, lie in a circle which is smallerthan the radius of the drum so that these inner ends bear against the surface of the drum. The yarn which is withdrawn must pass from under one finger to under the next and overcome a relatively constant resistance during withdrawal, so that such retarding ring does perform satisfactorily. On the other hand, such retarding ring, being formed of plastic by molding, is relatively costly and fragile, rendering such ring somewhat less than wholly satisfactory for its intended purposes.

The present invention has as its object the provision of a retarding means which retains all of the advantages of the retarding rings in aforementioned U.S. Pat. Nos. 3,648,939 and 3,702,176, while having none of its disadvantages.

SUMMARY OF THE INVENTION In accordance with the invention, the retarding device is obtained by using a conventional coiled or helical spring which has been partially flattened so that the windings of the spring are angularly related with respect to the longitudinal axis of the spring when the latter is in relaxed condition. The free ends of the spring are then secured to each other to form an endless spring having a generally circular configuration. In its free condition, the inner contour of the endless spring is smaller than the contour of the drum. Accordingly, the spring must be expanded for placing it, onto the drum, and once on the drum, the tension on the spring will cause the latters coils to bear against the surface of the drum. This arrangement enables the coils of the endless spring to firmly bear against the drum so that each of these coils defines a constant resistance to the yarn which must pass thereunder as it is axially withdrawn from the drum.

Since the endless spring has been partially flattened as aforedescribed, each individual coil thereof is angularly related with respect to a radius of the drum passing through the contact portion of coil and drum, in the direction of relative rotation of the yarn during its withdrawal from the drum, which contact portion is curved. It is apparent that the endless helical flattened spring, which defines the retarding element in accordance with the invention, can be formed so as to meet any specified yarn tension requirements. More specifically, the length or average contour of the spring, the number of windings per unit of length, the wire diameter, the diameter of the windings, and the angularity of the windings relative to the spring contour, can be preselected so as to provide the retarding characteristics which may be desired. Thus, all the advantages of the prior art retarding means are retained in the invention while at the same time providing these advantages with greater flexibility and at a reduced cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a storage feeder, with parts broken away, and having mounted thereon the yarn retarding means in accordance with the invention;

FIG. 2 is a top plan view of the storage feeder drum shown in FIG. 1, on an enlarged scale; and

FIG. 3 is an elevational view of the portion of the spring and drum within area 3 of FIG. 1, on an enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, storage feeding device 10 (similar to that shown in aforementioned U.S. Pat. No. 3,780,958) is provided with a drum 12 fixed against rotation, and a yarn winding member 14 adapted to rotate about drum 12 forming thereon a plurality of yarn windings which advance towards the free end of the drum, which stored yarn is axially withdrawn from the drum as intermittently demanded by a textile producing machine, such as a knitting machine, as fully described in aforementioned U.S. Pat. No. 3,780,958, assigned to the assignee hereof.

In accordance with the invention, there is provided adjacent the free end of drum 12 and in surrounding relation thereto retarding means 16 which applies a retarding force to the axially withdrawn yarn which passes between the retarding means 16 and the drum as it is withdrawn from the drum.

As best shown in FIGS. 2 and 3, retarding means 16 comprises a helical spring 18 whose free ends have been secured together to define an endless spring of related with respect to the longitudinal extent of the spring, before the free ends thereof are secured to form the endless generally circular shaped spring.

In the free condition of the endless spring 18, the inside diameter or contour of the spring is smaller than the outside diameter or contour of drum 12 so that spring 18 must be expanded before placing it onto the drum 12. When positioned on drum 12, as shown in FIG. 2, the id or inner contour of the expanded spring will, of course, coincide with the o.d. or outer contour of drum 12. The necessary spring expansion for enabling spring 18 to be placed on the drum causes the individual windings of the spring to bear against the surface of the drum.

The angularity of the windings created by the flattening of the spring enables the winding portions P which are engaged by the withdrawing yarn to extend in the direction of relative rotation of the yarn during its withdrawal as shown in FIG. 2, such being desirable for imparting uniform non-jerky retarding forces to the yarn being withdrawn. More specifically, portion P of each winding, which is curved, is inclined with respect to a radial line passing through P forming an angle a relative thereto which may be varied within a range extending from to 50 to obtain lesser or greater inclination as may be desired.

It is apparent that the retarding force applied by spring 18 to the yarn being withdrawn from the drum depends on the several parameters of spring 18. More specifically, the id. or inner contour of the endless spring must be smaller than the o.d. or outer contour of the storage drum. As the difference between the two contours increases, the force bearing against the drum by the independent windings, which must be surmounted by the withdrawing yarn, also increases. Also influencing the characteristics of the retarding force are the diameter of the wire forming the spring windings as well as the diameter of the windings themselves.

What is clearly evident is that all the parameters of spring 18 above described, including the angularity of the spring windings, can be preselected as desired to meet any required condition of operation as affected by the type of yarn being utilized and the nature of the textile producing machine receiving the yarn. The yarn being withdrawn, it is clear, is confronted by a plurality of spring coil portions which are curved and which are inclined in the direction of relative rotation of the yarn during its withdrawal from the drum, all of which fea tures provide the highly desirable control for the yarn.

It is well recognized that a storage feeding device of the type referred to herein is subjected to a wide variety of different yarns for different applications, each of which variations may require a retarding means having different characteristics making it necessary to have a plurality of retarding means normally available, which is costly. This cost element is substantially reduced where the retarding means is a metal spring which can be made inexpensively as is the case in accordance with the invention, especially as compared to the prior art in which the retarding means is a fragile plastic molded element.

As the yarn passes under spring 18, the latter may have a tendency to be axially displaced, especially in an application where the spring is under little tension in order to provide a relatively small retarding force. Such axial displacement may therefore be prevented by providing a shoulder on the drum as in aforementioned U.S. Pat. No. 3,648,939. While such shoulder is the sole means effective for preventing axial displacement in said patent, this is not the case in accordance with spring 18 of the present invention. More specifically, since spring 18 can be made of steel, the portion of drum 12 adapted to be surrounded by spring 18 may be suitably magnetized for retaining the spring thereon and prevent axial displacement thereof, dispensing with the need of a shoulder.

While the retarding means in accordance with the present invention has been described in association with a storage feeding device, it will be understood that it is equally applicable to control yarn axially withdrawn from any storage member onto which yarn has been wound, whether or not such storage member is part of a storage feedingdevice.

While there is herein shown and described the preferred embodiment of the invention, it will be understood that the invention may be embodied otherwise than as herein specifically illustrated or described, and that in the illustrated embodiment certain changes in the details of construction and in the form and arrangement of parts may be made without departing from the underlying idea or principles of this invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by letters patent is:

1. In a yarn storage device having a storage drum adapted to have yarn wound tangentially thereon and unwound axially therefrom, a retarding device surrounding said drum and adapted to have said yarn passed thereunder as it is axially withdrawn, said retarding device comprising a coiled spring whose opposite ends are secured to each other to form a continuous retarding ring having an inner contour smaller than the outer contour of said drum before said ring is mounted on said drum, whereby said ring is placed under tension when mounted on said drum, each coil of said spring having a curved portion in bearing engagement against said drum which defines a constant resistance to the yarn which passes thereunder as it is axially withdrawn from the drum.

2. The improvement in accordance with claim 1, wherein said coiled spring is partially flattened whereby the curved portion of each coil is inclined with respect to a radius of said drum passing through the point of engagement of said curved portion and said drum.

3. The improvement in accordance with claim 2, wherein the curved portion of each coil is inclined in the direction of relative rotation of the yarn during its withdrawal from the drum.

4. The improvement in accordance with claim 3, wherein the angle of inclination of the curved portion of each coil is between 10 and 50 with respect to said drum radius.