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Patent Searching and Data


Title:
A NEEDLE FOR A TUFTING MACHINE
Document Type and Number:
WIPO Patent Application WO/2001/077431
Kind Code:
A1
Abstract:
The needle module comprising a number of needles (1). A rod (6) extends perpendicularly to the needles through a through hole in each needle at the end opposite to the eye (2). The rod (6) directs the yarn (8) down the length of each needle.

Inventors:
Beverly, Ian (3 The Hawthorns Blackburn Lancashire BB1 9JW, GB)
Application Number:
PCT/GB2001/001580
Publication Date:
October 18, 2001
Filing Date:
April 06, 2001
Export Citation:
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Assignee:
SPENCER WRIGHT INDUSTRIES, INC. (1000 Tallan Building Two Union Square Chattanooga, TN, 37402, US)
Beverly, Ian (3 The Hawthorns Blackburn Lancashire BB1 9JW, GB)
International Classes:
D05C15/20; D05C15/00; (IPC1-7): D05C15/20; D05C15/18
Attorney, Agent or Firm:
Draper, Martyn John (Boult Wade Tennant Verulam Gardens 70 Gray's Inn Road London WC1X 8BT, GB)
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Claims:
CLAIMS :-
1. A needle for a tufting machine, the needle comprising a shank having an eye at one end, a mounting portion at the opposite end and a yarn feed groove extending from the eye towards the mounting portion, characterised by a rod attached towards the opposite end of the needle and projecting laterally from the needle.
2. A needle according to claim 1, wherein a through hole is provided in the needle, through which hole the rod extends.
3. A needle according to claim 2, wherein the rod is bent in at least one location in order to retain it in place.
4. A needle assembly provided with a plurality of needles according to any one of the preceding claims.
5. A needle assembly as claimed in claim 4, in which the rod is common to all of the needles.
Description:
A NEEDLE FOR A TUFTING MACHINE The present invention relates to a needle for a tufting machine, the needle comprising a shank having an eye at one end, and a mounting portion at the opposite end and a yarn feed groove extending from the eye towards the mounting portion. Such needles are widely used in the art.

One problem with needles of this type is that, as the yarn is fed into the groove at an angle, friction between the yarn and the backing material causes an increase in yarn tension which causes problems such as stretching of the backing material, unevenness in the pile height, an increased power requirement to achieve needle penetration and an increase in loose fibres.

In an attempt to overcome these problems, a thread-feeding element has been proposed in EP-A- 0882831. This thread-feeding element is essentially a guide which ensures that the yarn enters the top of the yarn feed groove and is then fed directly down the length of the needle thereby greatly reducing the contact between the yarn and backing material.

However, for various reasons, the only example which has proved practical is the double-eyed cranked needle shown in Figure 4 of EP-A-0882831. Even with this design, there a number of disadvantages that have limited the applications of this needle. The complex structure of the needle makes it expensive to produce.

The presence of the eye towards the upper end of the needle weakens the needle. The crank configuration limits the pitch (gauge) on in-line needle bars and modules. As the double-eyed configuration makes the needle difficult to thread, single staggered needle bars and modules are not practical. Thus, the needle has been used in only a limited number of applications.

A similar arrangement proposed by the applicant

has a needle is cranked such a way as to provide direct access to the top of the yarn feed groove.

However, this also suffers from high manufacturing costs and reduced stability at the 90° bend and is not suitable for dual sliding needle bar machines due to threading difficulties.

According to the present invention, a needle of the kind described is characterised by a rod attached towards the opposite end of the needle and projecting laterally from the needle.

This simple idea has a number of very important advantages. It is inexpensive to produce as it requires only that a rod be attached to an existing type of needle. The invention can be applied to any existing arrangement of needles. As it does not require a crank type configuration, it does not limit the pitch of the needles. The presence of the rod does not weaken the needle as does the presence of a second eye.

The rod may simply be welded to the needle, possibly in a groove in the needle. However, the current preference is for a through-hole to be provided in the needle, through which hole the rod extends. In this case, the rod is preferably retained in the through-hole by being bent at at least one location.

The needle may be mounted directly to a needle bar, or to a module which is fixed to a needle bar.

In either case, the invention extends to a needle assembly provided with a plurality of needles according to the present invention in which the rod is common to all of the needles. In this case, a yarn entrance guide will be formed by the needle, the adjacent needle, the rod, and the component to which the needles are mounted. This is a large area and provides for simple threading of the needle.

The rod is preferably chamfered at one end in order to facilitate insertion through the through- holes and to aid the insertion and extraction of a module from its backing bar without disturbing neighbouring modules.

An example of a needle and needle assembly constructed in accordance with the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a cross-section through a single needle showing the yarn threaded through the needle; Figure 2 is a plan view of a needle module incorporating five needles as shown in Figure 1; and Figure 3 is a side view of the modules shown in Figure 2.

In most respects, the structure of the tufting machine and the needles is entirely conventional, and further details will not be provided here.

The needle 1 has an eye 2 at its lowermost end and is mounted on a needle module 3 at its uppermost end. A yarn feed groove 4 extends from the eye 2 up the needle most of the way towards the module 3. The shank of the needle above the yarn feed groove 4 is provided with a through-hole 5 which is formed using EDM equipment. The hole preferably has a diameter of 1mm and maybe drilled either prior to the needle being mounted on the module 3, or all of the needles 1 may be mounted on the module 3 before all of the through- holes 5 for each needle in the module 3 are drilled together.

Once the holes are drilled, a hardened round steel pin 6 is inserted through the holes 5 and is locked in place by slightly bending the pin at one or more locations. A yarn entrance guide 7 for each needle is created in the area bound by the module 3,

the rod 6, the part of the needle 1 above the rod 6, and the facing part of the adjacent needle. This is a relatively large area through which it is easy to thread the yarn 8. The yarn 8 extends down the yarn feed groove 4 and through the eye 2. The tension applied to the yarn will ensure that it is always maintained in close proximity with the rod 6, and the yarn feed groove 4.

As shown in Fig. 2, the rod protrudes from the lefthand side of the module. This will engage with an adjacent needle in the adjacent module to form a guide for that needle. At one end of a row of needles, a dummy needle can be provided so as to provide a yarn entrance guide for the endmost needle.

Although the rod 6 is shown extending across the needles close to the module 3, there may be some advantages in having it extend across at a location lower down the needles such that it intersects the yarn feed groove 4.