JPH057270Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shuttleless loom, and particularly to a yarn feeding device for holding a yarn feeding section (cheese) of weft yarns fed to a weft inserting device. It is something.

[Prior Art] The weft yarn supplied to the weft insertion device is fed to a yarn feeding device 1 as shown in FIG. 5, which is usually called a yarn feeding stand.
In order to continuously supply the weft, a plurality of cheeses 2a and 2b (usually two) are held in the yarn feeding stand 1, and are released first. The tail thread 3a, which is the weft end of one cheese 2a, is connected to the other cheese 2 which is waiting.
It is connected in advance to the weft starting end 3b of the cheese 2b, so that when the weft from one cheese 2a finishes being fed, the weft from the other cheese 2b is continuously fed.

In this case, the weft yarn being released from the cheese 2a at a relatively high speed causes a phenomenon called ballooning as is well known, so that the balloon of the weft yarn (not shown) is caused by the tail yarn 3a of one cheese 2a and the weft yarn of the other cheese 2b. When it comes into contact with the joint area between the tip 3b and the weft, the released weft thread is connected to the waiting cheese 2.
As a result, two weft yarns are simultaneously fed toward a weft insertion device (not shown), resulting in a weft insertion error.

In order to avoid such an unexpected situation, conventionally, a tail thread gripping member 4 (see Fig. 6) is arranged on the yarn feeding stand 1, and this tail thread gripping member grips the tail thread and removes the released weft thread. This prevented the tail string from getting caught in the balloon. As the tail string gripping member 4, as shown in FIG. 6A, a short plate member 4b having a similarly bent tip is attached to the bent tip of a substantially J-shaped plate member 4a by an appropriate means. Attach it to
There are those that grip the weft thread between both ends, and those that grip the weft thread using relatively strong artificial hair-like fibers 4d planted on a flat plate 4c, as shown in Fig. 6B. Ta.

[Problem to be solved by the invention] However, in order to prevent the tail yarn from being caught in the released weft, it is necessary to simply place the tail yarn on the artificial hair 4d as shown in Fig. 6B. Since the gripping force is insufficient just by placing the thread in place, the gripping force must be increased to some extent by using an elastic tail gripping member as shown in FIG. 6A. However, when the tail thread gripping member as shown in FIG. 6A is used, the gripping force is strong, so thread breakage sometimes occurs when the weft thread is transferred from one cheese to the other.

Therefore, an object of the present invention is to provide a yarn feeding device for a shuttleless loom that can reliably prevent entanglement of the weft yarn while it is being released, and can also transfer the weft yarn without causing yarn breakage. That is.

[Means for Solving the Problems] For this purpose, the present invention includes at least two yarn feeding sections, and the tail yarn of the yarn feeding section to be released first is the weft yarn starting end of the yarn feeding section to be released next. The yarn feeding device is connected to the yarn feeding section, and the region of the connecting portion is gripped by the tail yarn gripping device, the yarn feeding device including: (a) a sensor for detecting a predetermined diameter of the yarn feeding portion; The yarn gripping device is composed of a pair of relatively movable weft gripping members so that the tail yarn gripping force can be adjusted; The present invention is characterized in that it includes an actuating device that operates the tail string gripping member of the tail string gripping device in a direction in which the tail string gripping force decreases.

[Operation] When the weft yarn is released from one yarn feeding section, the tail yarn gripping device is activated by the actuating device, and the tail yarn is gripped with a strong gripping force between both tail yarn gripping members. As the release continues, the diameter of the yarn feeding section gradually decreases, and when it reaches a predetermined diameter near the point at which the weft is to be transferred from this yarn feeding section to the other yarn feeding section, this predetermined diameter decreases. The sensor detects and sends a detection signal to the actuating device. Therefore, the actuating device stops the operation of the tail thread gripping device, so that the gripping of the tail thread is switched to a relatively weak gripping force suitable for weft transfer.

[Embodiments] Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which the same reference numerals indicate the same or corresponding parts.

FIG. 1 is a front view showing a yarn feeding device 1 according to the present invention having a similar type to the yarn feeding stand shown in FIG. 5, with its longitudinal length shortened, and FIG. This is a side view similarly showing the yarn feeding device 1 shown in FIG.
A tubular column 5b extends upward from the column 5b.
The yarn feeding portions or cheeses 2a, 2b each include support sleeves 6a, 6b which preferably fit into the column 5b in a position-adjustable manner, and brackets 7a, 7b (bracket 7b is not shown) which are appropriately attached to the sleeves. (1) and support arms 8a, 8b (support arm 8b not shown) extending substantially horizontally from the bracket.

Further, a support bracket 10 having artificial hair 9 is attached to the column 5b directly above the upper support sleeve 6b by an appropriate means, and the artificial hair 9 is placed opposite the artificial hair 9 of the support bracket 10. A tail thread gripping plate 11 that grips the tail thread in cooperation with the weft thread is disposed at a position where it does not touch the ballooning of the weft thread. The tail thread gripping plate (the tail thread gripping member) 11, which together with the artificial hair 9 (the tail thread gripping member) constitutes the tail thread gripping device 17, is movably coupled to the actuating device 18. That is, in a preferred embodiment, the tail thread gripping plate 11 is connected to a piston rod 13 of an air cylinder 12 mounted on the column 5b via a bracket 14, and is operated by the air cylinder 12 as described below. be done. Further, two L-shaped brackets 15a, 15b are attached to the upper end of the column 5b in a U-shape as a whole, and cheese diameter detection sensors 16a, 16b are attached to each bracket 15a, 15b.
It is attached to the tip of 15b.

In the illustrated embodiment, the cheese diameter detection sensor is a conventional cheese diameter detection sensor that measures the time it takes for ultrasonic waves emitted from the sensor to reflect off the cheese circumferential surface and return to the sensor, and compares the time with a reference time to detect the cheese diameter. However, as used in Japanese Patent Application No. 45388/1988 filed by the same applicant as the present application, ``Operation Control Method for Shuttleless Loom'', cheese is placed between the two sides. It is also possible to use a cheese diameter detection sensor that consists of a light emitter and a light receiver and determines the light receiving state as a predetermined diameter of the cheese, or to detect the number of weft insertions from the first weft insertion of the cheese. . Further, although an air cylinder is employed as the actuating device 18, other appropriate devices such as a solenoid may be used.

FIG. 3 shows a main part of an example of an electric circuit that controls the operation of the air cylinder 12 based on signals from the cheese diameter detection sensors 16a and 16b of the yarn feeding device 1 described above.

Next, the yarn feeding device 1 having the configuration as described above will be described.
The operation will be explained with reference to FIGS. 1 to 3. For example, after placing the joint area between the tail thread 3a of one cheese 2a and the weft start end 3b of the other cheese 2b on the artificial wool 9 of the support bracket 10, the operator By pressing a push button switch 19 that can be installed on the operation control panel, the normally closed contacts 20 of the cheese diameter detection sensors 16a and 16b are opened.
As a result, the normally open contact _R1 of the relay R is closed and the relay R is self-retained, and the normally open contact _R2 is closed and the electromagnetic valve for operating the air cylinder 12 described above is closed. (not shown)
The solenoid SOL is energized and the solenoid valve opens to supply air to the air cylinder 12. Therefore, the piston rod 13 is urged downward, and the tail thread gripping plate 11 connected to the piston rod 13 also moves downward, collaborating with the artificial hair 9 to close the joining area between the tail thread 3a and the weft starting end 3b. Hold firmly.

If the machine is operated in this state, the weft yarn is fed from the cheese 2a toward a weft insertion device (not shown), and weft insertion is performed in a well-known manner.
When weft insertion is repeated in this way and the diameter of the cheese 2a is reduced to a predetermined diameter with a small amount of remaining weft, the cheese diameter detection sensor 16a associated with the cheese 2a detects this state, and the detection signal is used to detect the normally closed state as described above. Contact 20 opens and the circuit of relay R is interrupted.
Normally open contact _R2 , which was closed, opens and the solenoid
As the SOL is demagnetized and the tail yarn gripping plate 11 connected to the air cylinder 12 via the piston rod 13 rises, its gripping action disappears, and the weft yarn simply rests on the artificial hair 9. Therefore,
The weft supply is smoothly switched from one cheese 2a to the other cheese 2b.

In the embodiment shown in FIGS. 1 to 3, the tail yarn is held by one tail yarn gripping device, but in the yarn feeding device 1 shown in plan view in FIG. 4, each support arm 8a, A separate tail thread gripping device is provided at 8b. The structure and operating mechanism of each tail thread gripping device may be the same as in the embodiment described above.

[Effect of the invention] As described above, while the weft thread is released from one cheese, the joint region between the tail thread of the same cheese and the weft thread start end of the other cheese is held with a strong gripping force by the tail thread gripping device. Since the weft is held in place, even if the released weft touches the joint area and attempts to wind it up, no such inconvenience will occur. Further, when the weft yarn is transferred from one cheese to the other cheese, the strong gripping force is released, so that the transfer is carried out smoothly and no yarn breakage occurs.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a yarn feeding device according to the present invention with its longitudinal length shortened, and FIG. 2 is a side view showing the yarn feeding device of FIG. 1 similarly shortened. FIG. 3 is a diagram showing an example of an electric circuit that controls the operation of the air cylinder based on the signal from the cheese diameter detection sensor of the yarn feeding device described above, and FIG. FIG. 5 is a perspective view of a conventional yarn feeding device, and FIGS. 6A and B show an example of a tail thread gripping member used in the yarn feeding device of FIG. FIG. 1... Yarn feeding device, 2a... One yarn feeding section, 2b
...Other yarn feeding section, 3a... Tail thread, 3b... Weft starting end, 9... Artificial hair (tail thread gripping member), 11...
Tail thread gripping plate (tail thread gripping member), 12... Air cylinder, 13... Piston rod, 16a, 16b
... Sensor (cheese diameter detection sensor), 17 ... Tail thread gripping device, 18 ... Actuation device.

Claims (1)

[Claims for Utility Model Registration] At least two yarn feeding sections are provided, the tail yarn of the yarn feeding section to be released first is connected to the weft starting end of the yarn feeding section to be released next, and In a yarn feeding device in which a region is gripped by a tail thread gripping device, (a) a sensor is provided for detecting a predetermined diameter of the yarn feeding portion, and (b) the tail thread gripping device applies a tail thread gripping force. (c) the tail yarn gripping device of the tail yarn gripping device is configured to include a pair of weft gripping members that are movable relative to each other so as to be adjustable; A yarn feeding device for a shuttleless loom, comprising: an actuating device that operates a member in a direction that reduces tail yarn gripping force.