GB2402680A

GB2402680A - Yarn feed apparatus

Info

Publication number: GB2402680A
Application number: GB0419136A
Authority: GB
Inventors: David Waite
Original assignee: Griffith Textile Machines Ltd
Current assignee: Griffith Textile Machines Ltd
Priority date: 2001-08-02
Filing date: 2001-08-02
Publication date: 2004-12-15
Anticipated expiration: 2021-08-02
Also published as: GB2378189B; GB2402680B; GB0419136D0; BE1016040A3; DE10235200A1; GB0118867D0; GB2378189A

Abstract

A yarn feed apparatus comprises a plurality of yam stores Ys, a plurality of yarn tensioners 22 and a yarn drawing means 20 located between said stores and tensioners. The yarn drawing means are arranged to draw a predetermined length of yarn from its store which can then be drawn through its respective tensioner. The yarn drawing means may be a displaceable rod 27, where the distance D can be set to determine the size of the loop L and thus the length of yarn to be drawn. The plurality of tensioners may be arranged in a row (see Fig 1) and the rod 27 may extend along this row. The tensioner may be a roll 24. The yarn may be consumed by a device (CD, Fig 1) such as a loom.

Description

YARN FEED APPARATUS

The present invention relates to a yarn feed apparatus.

According to one aspect of the present invention there is provided a yarn feed apparatus including a plurality of yarn stores, a plurality of yarn tensioners arranged so that each yarn from each yarn store is fed through a respective yarn tensioner, and yarn drawing means located between the plurality of yarn stores and plurality of yarn tensioners, the yarn drawing means being arranged to draw a lo predetermined length of yarn from its store in readiness for drawing of the yarn through its respective tensioner.

Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which: Figure I is a schematic plan view of a yarn feed apparatus according to an embodiment of the present invention; Figure 2 is a side view of the apparatus shown in Figure 1; Figure 3 is an end view of the apparatus shown in Figure 1; and Figures 4a, 4b are part plan views similar to Figure 1 showing the apparatus in different tension modes.

Referring initially to Figures 1 to 3, a yarn feed apparatus according to an embodiment of the present invention is generally shown at 10. The apparatus includes a first yarn tensioner 22 and a second yarn tensioner 50 through which yarn Y is intermittently drawn by a consuming device CD (such as a loom).

Typically, as shown in Figure 1, a plurality of apparatuses 10 according to the present invention are located side by side in a row so that each apparatus draws yarn from an associated individual yarn store, there being a plurality of side by side yarn stores Ys.

For simplicity, only one apparatus 10 is illustrated in full in the drawings.

The apparatus further includes a yarn drawing means 20 located upstream of the first tensioner 22 which functions to draw a predetermined length of yarn Y Tom the yarn store Ys. The yarn store Ys may be of any suitable type, for example a yarn package or a yarn store as disclosed in our European Patent 0 422 093.

Preferably the yarn drawing means 20 includes a static guide preferably in the form of a rod 23, and a yarn drawing member, preferably in the form of a rod 27 which is movably mounted inbetween the static guide 21 and the yarn tensioner lo 22. Preferably the yarn tensioner 22 is in the form of a roller 24 and co-operating plate 25. The yarn tensioner 22 acts to apply tension to the yarn Y by virtue of gravity bias of the roller 24 onto the plate 25.

The rod 27 is reciprocally movable from a rest position (shown in solid lines in Figure 2) to a displaced position (shown in broken lines in Figure 2).

At its rest position, the rod 27 is located adjacent to a linear path of travel of the yarn Y as determined by the rod 23 and tensioner 22.

When the rod 27 is moved to its displaced position, the tensioners 22 and act as a yarn brake and so a yarn loop L is drawn from the yarn store only.

The distance D between the rest and displaced positions of the rod 27 is chosen to produce a desired length of yarn in the yarn loop L. The mechanism for reciprocally displacing rod 27 may be adapted so as to enable the distance D of displacement to be varied as desired. After drawing loop L, the rod 27 is returned to its rest position leaving the loop L in a free condition. It will be appreciated, therefore, that the loop L is free of tension and is held in readiness to be drawn through the tensioner 22.

Downstream of tensioner 22 there is provided the second yarn tensioner 50 which is selectively adjustable for adjusting the tension applied to yarn Y. The adjustable yarn tensioner 50 includes a yarn trap 51 and a first movable yarn guide 52 located inbetween yarn trap 51 and the yarn tensioner 22.

Located downstream of the yarn trap 51, the adjustable tensioner 50 further includes a second movable yarn guide 55. Yarn Y is guided by both guides 52 and 55 along a path of travel through the trap 51.

The trap 51 is preferably in the form of a resilient strip 53 of material which is anchored at one end to a planar support 60. The strip 53 is inclined lo relative to the support 60 to define therebetween an open mouthed wedge shaped passage 61. When yarn is guided into the bottom of the passage 61 it is wedgedly trapped between the strip 53 and support 60.

The second guide 55 is preferably in the form of a yarn guide eye 56 mounted on the end of a spring 57.

The second guide eye 56 is resiliently biased to a rest position (as shown in solid lines in Figures 1, 4A, 4B). In its rest position, the second guide eye 56 is located to define a first outward path of travel P of yarn from the trap 51 which ensures that the yarn is guided into the bottom of the passage 61. Accordingly, when the guide eye 56 is in its rest position, yarn is trapped by trap 51.

During use, yarn Y is drawn by a consuming device such as a loom located downstream of guide 55. When this occurs, guide eye 56 is resiliently deflected from its rest position to a deflected position (as shown in broken lines in Figures 1, 4A and 4B).

As the guide 55 is deflected, it alters the angle of the outward path of travel Pit relative to the trap 51. Eventually continued deflection of the guide 55 will result in the path of travel of the yarn through the trap 51 being determined by a direct line of path PD between guides 52 and 55 when this occurs, the direct linear path PD is chosen to guide the yarn through the trap 51 at a spaced location from the bottom of passage 61. Accordingly in this condition, the yarn Y passes through trap 51 without being trapped.

In this condition, whilst yarn is being drawn by the consuming device, the s tension applied to the yarn being supplied to the consuming device is a combination of the tension applied by tensioner 22 and by guide 55.

The amount of tension applied by tensioner 22 is constant but that applied by the guide 55 will vary dependent upon the rate of yarn being drawn by the lo consuming device during a yarn consuming cycle, e.g. a weft insertion in a loom or a pile forming cycle in a carpet loom. Thus, at the beginning of the consuming cycle, as yarn is drawn by the consuming device, the guide 55 is initially moved from its rest position to a yarn release position whereat the direct path PD is initially attained. At the release position, the guide 55 applies a predetermined amount of tension onto the yarn being drawn. If the rate of consumption increases, the guide 55 will be further deflected beyond its release position and thereby apply a higher tension.

The level of the tension applied by the guide 55 when reaching its release position may be adjusted by moving the position of yarn guide 52 in order to change the angle of the inward path of travel P' of the yarn relative to the trap 51.

As illustrated in Figures 4A, 4B, the guide 52 is preferably in the form of a pin 52a mounted on an elongate support bar 52b which is slidably mounted for longitudinal movement. By moving the guide 52 to the left, the angle is increased. Accordingly, the distance that guide 55 has to be deflected in order to attain its release position is reduced. Since the inherent bias for returning the guide eye 56 to its rest position progressively increases as a function of its deflection from its rest position, the amount of tension applied by the guide at its release position is thereby reduced.

Similarly, if the guide 52 is moved to the right, angle is reduced and so the guide eye 56 has to move a greater distance before reaching its release position. Accordingly, the amount of tension applied is thereby increased.

A range R of positions to which the guide 52 may be selectively moved is schematically shown in Figures 4A, 4B. Moving the guide 52 to any position in this range enables the guide 55 at its rest position to guide yarn to be trapped in tap 51 and enables the guide 55 to be moved to a release position whereat guides 52 and 55 co-operate to guide yarn through the trap 51 without being tapped.

After the consuming device has stopped consuming yarn, it will release a small amount of yarn. This permits the guide eye 56 to return to its rest position and trap yarn in trap 51 in readiness for the yarn feed cycle to be repeated. As the guide 55 returns to its rest position, it takes up slack in the yarn between itself and the consuming device and also imparts a residual low tension therein.

Claims

1. A yarn feed apparatus including a plurality of yarn stores, a plurality of yarn tensioners arranged so that each yarn from each yarn store is fed through a respective yarn tensioner, and yarn drawing means located between the plurality of yarn stores and plurality of yarn tensioners, the yarn drawing means being arranged to draw a predetermined length of yarn from its store in readiness for drawing of the yarn through its respective tensioner.

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2. Apparatus according to Claim 1 wherein the yarn drawing means includes a reciprocally mounted yarn drawing member which is movable from a rest position to a displaced position, the member in its rest position being located adjacent a path of Gavel of a yarn when drawn from its store and being located in its displaced position at a predetermined distance from its rest position, the movable member on moving to its displaced position from its rest position drawing a predetermined length of yarn to define a yarn loop upstream of its respective yarn tensioner, the movable member on returning to its rest position leaving said yarn loop in a free condition.

3. Apparatus according to Claim 2 wherein said plurality of tensioners are arranged in a row and said yarn drawing member is a rod extending along said row.

4. A method of intermittently drawing yarn from a plurality of yarn stores, the method including feeding each yarn through a respective yarn tensioner, creating a free loop in each yarn upstream of its respective tensioner by drawing at the same time a predetermined length of yarn fiom each store prior to drawing yarn through said tensioner and then drawing each yarn through its respective yam tensioner.

4. A method of intermittently drawing yarn from a yarn store, the method including feeding said yarn through a yarn tensioner, creating a yarn loop in said yarn upstream of said tensioner by drawing a predetermined length of yarn from its store prior to drawing yarn through said tensioner and then drawing the yarn through the yarn tensioner.

Amendments to the claims have been filed as follows

1. A yarn feed apparatus including a plurality of yarn stores, a plurality of 3 yarn tensioners arranged so that each yarn from each yarn store is fed through a respective yarn tensioner, and yarn drawing means located between the plurality of yarn stores and plurality of yarn tensioners, the yarn drawing means bemg arranged to draw a predetermined length of yarn from each store to form a free loop in each yarn in readiness for drawing of the yarn through its respective tensioner.

2. Apparatus according to Claim l wherein the yarn drawing means includes a reciprocally mounted yarn drawing member operable on each yarn extending from each yarn store to a respective yarn tensioner, the yang drawing member being movable from a rest position to a displaced position, the member in its rest position being located adjacent a path of travel of each yarn when drawn from its store and being located in its displaced position at a predetermined distance from its rest position, the movable member on moving to its displaced position from its rest position drawing a predetermined length of each yarn to define a yarn loop upstream of its respective yarn tensioner, the movable member on returning to its rest position leaving said yarn loop of each yarn in a free condition.