EP0200810A1

EP0200810A1 - Looper for tufting machine

Info

Publication number: EP0200810A1
Application number: EP85108516A
Authority: EP
Inventors: Sota Yoshino
Original assignee: Asahi Trading Co Ltd
Current assignee: Asahi Trading Co Ltd
Priority date: 1985-05-02
Filing date: 1985-07-09
Publication date: 1986-11-12
Also published as: JPS61183994U

Abstract

® An improved looper for tufting machines is proposed which has a stopper (1) for preventing the piles from getting out of the looper and a plate spring butting against the lower edge of the stopper. The stopper has its lower edge (2) formed with an inverted U-shape recess. A tip (10) of cemented carbide is attached to the stopper in the recess. The piles will not get damaged because of the provision of the recess.

Description

This invention relates to improvement in loopers for use with tufting machines for manufacturing pile carpets, tufted carpet in particular.
To manufacture carpets with tufting machines, a plurality of needles arranged in parallel so as to move up and down are inserted from the back of the ground fabric. The pile yarns in the needles are then engaged . by a plurality of the loopers provided at the right side of the ground fabric. When the needles are pulled up, the piles are left projecting from the surface of the ground fabric. Repetition of this operation in succession forms a tufted carpet with a tuft of loop piles or cut piles formed by cutting the loop piles with a knife.
As shown in Fig. 5, a conventional looper for the tufting machines has a pile yarn stopper 1', the lower edge 2' of which extends straight to the frontmost end, and a plate spring 3' butting with the lower edge of the pile yarn stopper. With this configuration, pile yarns are pulled out of the stopper 1' of the looper to make a carpet of loop piles. When piles are left in the stopper 1', a knife goes up to cut off the loops to make a carpet with cut piles.
Such conventional loopers have the following problems.

(1) Pile yarns are engaged by the straight stopper of the looper in tight contact with the stopper under tension. Accordingly, they are abraded by the stopper and get damaged as the looper moves forward and backward.
(2) In the case of cut piles, if the pile yarns engage in the stopper without loop, when they are cut by contact of a blade on the looper with the knife, so called "J cut" with different pile lengths at the right and left will be formed. This impairs the feeling of the carpet. At shearing, longer piles have to be cut to the length of shorter piles. This increases the consumption of pile yarns and makes the carpet more expensive.
(3) In manufacturing a carpet composed of cut piles ; and loop piles, the tension present in the preceding step badly affects the pile yarns at the boundary of the two piles. This prevents smooth change between cut piles and loop piles. This leads to disordered pattern and degrades the surface quality of the carpet. (4) Life of steel loopers of a conventional type was as short as 80,000 to 100,000 m expressed in terms of the quantity of pile yarns used, and all the loopers had to be replaced at least once every season.

The above problems are not only limited to cut loop loopers, but are also applicable to plain cut loopers and multi-level cut loopers in which the plate spring moves forward and backward to change from the cut piles to loop piles and vice versa.
An object of the present invention is to provide an improved looper for tufting machines which obviates the abovementioned shortcomings.
Other objects and features of the present invention will become apparent from the following description taken with reference to the accompanying drawings, in which:

Fig. 1 is a front view showing how a cut loop looper embodying the present invention is used;
Fig. 2 is a front view of the looper with no tip attached;
Fig. 3 is a front view of the looper with the tip attached;
Fig. 4 is a front view of a plain cut loop looper embodying the present invention; and
Fig. 5 is a front view of a prior art looper. The looper A for tufting machines according to the present invention has a pile yarn stopper 1 which has its lower edge 2 made into an inverted U-shape at 3 by denting its rear part slightly. The looper A has a groove 5 in one side of its base 4. A plate spring 6 is engaged in the groove. A part of the top end of the plate spring 6 is put in contact with the lower edge 2 of the stopper 1. As the material of the looper, high speed steel is used for example. As shown in Fig. 3, it is preferable to form a shallow recess at the rear part of the lower edge 2 and to braze a tip 10 made of cemented carbide and having the same shape so as to at least partly fill the shallow recess, a front edge 8 of the recess, and its rear edge 9. In the drawings, 11 is a knife, 12 is a needle, 13 is a pile yarn, and 14 is the ground fabric.

Basic operation of the tufting machine using the loopers A of the present invention is the same as that of conventional tufting machines. After the needles 12 with the pile yarns 13 passed through the small holes at their tip have come down through the ground fabric · 14, the loopers A advance in a reverse direction to the feeding direction of the ground fabric 14, until their front end gets between the needle 12 and the pile yarn 13. As the needles go up, the pile yarns 13 remain in loop from and with tension in the lower edge 2 of the stopper 1 of the looper. Then the loopers go back. If the quantity of yarn supply is limited strictly in the case of cut loop loopers, the pile yarns 13 in loop form are pulled out of the looper and form loop piles without being cut by the knife 11. If the quantity of yarn supply is not limited when the looper goes back, the pile yarns 13 in loop form are prevented from being pulled out by the plate spring 6 butting against the lower edge of the stopper 1 and remain in the looper A and move backwardly as the ground fabric 14 moves. As the knife 11 goes up, the pile yarns are cut by the contact of the looper with the knife 11, so that cut piles are formed.
In the above case, the pile yarns 13 in loop form stopped with tension in the stopper 1 of the looper are abraded by the stopper as the looper moves forward and backward, if it is of a conventional type. On the looper of the present invention, however, the stopper 1 is made to an inverted U-shape at 3 by denting at the rear part as shown in Fig. 1 to Fig. 4. As the ground fabric 14 move, therefore, the pile yarns 13 in loop form move rearwardly as shown in Fig. 1 and are caught in the inverted U-shape part 3. Thus the tension is released. Accordingly, the inverted U-shaped part 3 of the stopper 1 does not come into tight contact with the pile yarn 13 even when the looper moves forward and backward, so that the pile yarn 13 will not be abraded or damaged.
In the case of cut piles, the pile yarn 13 is cut with tension released. Accordingly, the pile length is even between the right and left, "J cut" will not be formed. The consumption of pile yarn can be saved. At the boundary between the cut piles and loop piles, tension applied to the pile yarns in the preceding step is not left unlike in the conventional looper, so that each pile can be formed clearly for fine finish at the boundary.
The inverted U-shape part 3 at the rear part of the stopper 1 makes it possible to attach a tip 10 made of cemented carbide so that its lower edge will not catch the pile yarn 13. Therefore, pile yarns are not caught by the tip when the looper moves forward and backward, and the looper can be used to the expiry of the life of the tip 10. The looper according to the present invention, therefore, is durable for 250,000 to 300,000 meters of pile yarn while the conventional type is for about 80,000 meters only. The looper of the present invention can also be used for another 250,000 to 300,000 meters simply by grinding the tip 10. The brazed part does not affect the pile yarn 13 directly by forward backward motion of the looper even if the brazing is peeled off. Because the inverted U-shaped part 3 is provided at the stopper 1 of the looper, the distance between the ground fabric 14 and the piles becomes shorter by the dent even though the distance between the fabric and the looper is the same. Accordingly, the pile length for cut piles can be shorter, which makes smaller the difference from the length of loop piles. The above is not only true for cut loop loopers but also for plain cut loop loopers in which the plate spring 6 moves forward and backward for switching between cut piles and loop piles as shown in Fig. 4.
The looper of the present invention has the following effects:

a. Since the pile yarns engaged in loop form are released from tension in the looper, they are not abraded or damaged by forward-backward motion of the looper unlike in the conventional loopers.
b. For cut piles, the pile length after cutting is equal between the right and left sides and "J cut" will not result. The feeling is improved and the consumption of pile yarns can be saved since the loss by shearing is reduced.
c. In manufacturing carpets composed of cut piles and loop piles, tension in the preceding step is not left on the pile yarns at the boundary unlike with conventional loopers. Accordingly, disordered pattern will not result and the boundary can be finished neatly.
d. Since a tip made of cemented carbide can be attached to the stopper so that the pile yarns will not be caught, the looper can be used to the expiry of the life of the tip. The life of conventional loopers is about 80,000 meters in terms of the quantity of pile yarn used. Carpet makers who usually use 25,000 to 30,000 meters in one season had to replace all the loopers at least once in every season. The life of the looper of the present invention is 250,000 to 300,000 meters and there is no need of replacing any loopers in the middle of a season. Moreover, by grinding the tip, the loopers can be used for another 250,000 to 300,000 meters.
e. Since the length of cut pile can be shorter by the dent of inverted U-shape, the step at the boundary between cut piles and loop piles can be less, which makes the finished carpets more flat.

Claims

1. In a looper for use with a tufting machine, said looper comprising a body formed with a groove on one side thereof, a stopper means extending upwardly from said body, and a plate spring mounted in said groove so as for its top to butt against the lower edge of said stopper means to prevent the piles from getting out of the looper, the improvement being that said lower edge of said stopper means is formed with an inverted U-shape recess.

2. The looper as claimed in claim 1, wherein a tip made of cemented carbide is attached to the looper in said recess.