JP2828783B2 - Weighing weft feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weft feeder for a fluid jet loom capable of measuring a weft to be inserted into a loom shed.

[0002]

2. Description of the Related Art As is well known, a weft feeder of this type comprises an electric motor for rotating a winding arm, and a fixed arm for winding the yarn as a winding portion forming a weft reserve whose length is controlled by a suitable sensor. And a drum.
A loom nozzle for firing a weft into a shed of a warp draws a weft of a length necessary for inserting each weft from a weft feeder drum. This length is surveyed and controlled by counting the number of winding outs by the weft feeder by an appropriate means.
When the yarn to be launched into the loom shed at the exit of the weft feeder reaches a predetermined length, the drum is stopped by a device provided with a rod that engages with the yarn at the exit of the feeder. Is movable between a protruding operation position positioned in a cavity formed in the vicinity of the drum free end of the drum peripheral surface. Preferably, the weft stopping device is an electromagnetic device having a rod protruding from the movable core. A yarn stop rod provided on the movable core, and a return spring adapted to move the yarn stop rod between a retreat rest position and a projecting yarn stop position so as to hook and stop the yarn at the outlet of the weft feeder. Configure as

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a measuring weft feeder capable of improving the performance of a weft feeder by improving an electromagnetic yarn stopping device and a cavity formed on a drum peripheral surface.

During the operation of the weft feeder, the thread constantly rubs against the rod of the electromagnetic stopping device, causing wear in the thread engaging area of the rod to form grooves and / or notches, and after a short period of time. The device becomes unusable. In the past, attempts have been made to overcome the drawbacks of forming the rod of the stop device from metal and to make it as wear resistant as possible. Such rods were formed of a material having low wear resistance, but had a surface treatment or surface coating that provided wear resistance. However, this solution has not yielded satisfactory results.

[0005]

SUMMARY OF THE INVENTION The present invention has solved the above-mentioned problems by properly securing a rod of ceramic material to a ferromagnetic core of a device.

In order to solve the above-mentioned problems, the present invention provides an electromagnetic yarn stopping device including at least one electromagnetic coil, a movable core made of a ferromagnetic material which is attracted by the coil, and the movable core. A thread stop rod, and a return spring adapted to move the thread stop rod between a retreat rest position and a projecting thread stop position so as to hook and stop the thread at the outlet of the weft feeder. In the measuring weft feeder, wherein the end of the rod is positioned in a cavity formed near the free end of the drum at the peripheral surface of the drum, the movable core of the yarn stopping device is made of a ferromagnetic material. Formed by a substantially cylindrical hollow head and a cylindrical rod of ceramic material axially positioned in the hollow interior of the head, the outer surface of said rod and the hollow head On the inner surface, grooves are provided along the quasi-lines of these surfaces, and the remaining space between the head and the rod is injected and filled with a plastic material, and the rod is fixed to the head. .

In a preferred embodiment of the present invention, the rod and the groove of the hollow head of the yarn stopping device are arranged so as not to be aligned with each other when the two parts of the movable core are mounted, and the projecting free end of the rod is provided. Round.

According to the apparatus formed in this manner, a brittle rod which is apt to be broken when a bending stress, particularly an impact stress is applied, can be used, and the cavity of the drum peripheral surface for accommodating the end of the thread stop rod can be used. It is more preferable to improve

The electromagnetic yarn stopping device can be formed according to two different principles. That is, the rod is retracted into the apparatus during the rest state, or the rod projects from the apparatus during the rest state and engages with the cavity formed on the drum peripheral surface.

In the case of the second configuration, an electromagnetic stopping device provided with a single magnet is employed to ensure that the yarn is stopped when the device is not operating.

According to recent construction techniques, the drum on which the yarn reserve is wound is loosely mounted on the motor shaft to prevent it from rotating (usually a permanent magnet fixed to the drum and another mounted on the body of the metering weft feeder). Rotation is prevented by the magnetic field generated by the opposing magnet).

According to this configuration, under the action of an external force,
The drum can be rotated about the drum axis.
This rotation occurs in the form of a reciprocating vibration when setting up the weft feeder. This is seen when trying to expand the drum during handling or use, when the diameter of the drum is variable, when trying to unwind the drum from the yarn reserve.

[0013] During rotation or reciprocating oscillation of the drum, the rod of the electromagnetic stop device abuts against the wall of the cavity containing the rod end. In this case, both the rod and the wall are damaged (there is a great possibility that the rod will be broken if the material is brittle as in the present invention).

This disadvantage can be solved by positioning the walls of the rod free end receiving drum cavity of the yarn stopping device according to the generatrix of the drum and inclining these walls so that they expand outwardly from one another.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

The metering weft feeder for supplying the weft to the fluid jet loom comprises an electric motor 1 for rotating the winding arm 2 and a drum 3 held in a stopped state. As a winding, forming a reserve 5 controlled by a sensor 6, the length of the winding being adjustable by changing the radial position of the column 7, which column 7 Can be changed. In such a measuring weft feeder, the yarn 4 supplied to the loom stops after a yarn of a predetermined length is pulled out by the loom nozzle. This operation is achieved by the electromagnetic device 8. In this case, the rod 9 moves to the projecting position, enters the cavity 10 provided on the peripheral surface of the drum 3 near the free end of the drum 3, thereby engaging the yarn 4 and stopping the yarn 4.

FIG. 2 shows a conventional electromagnetic yarn stopping device. The device 8 has a main body 11 fixed to a measuring weft feeder and containing an electromagnetic coil 12, a movable core 13, and a spring 14. In addition, the device 8 can be provided with one or more coils,
A configuration different from the illustrated configuration may be employed.

In the device 8 shown in FIG. 2, the coil 12 acts to pull the movable core 13 into the rest position against the action of the spring 14, which spring 14 moves the rod 9 of the core into the cavity 10 of the drum 3; The operation of maintaining the projecting yarn stop position is performed.
Alternatively, a spring can be designed to keep the movable core in the rest position, and an electromagnetic coil can be provided to move the core to a working position where the rod 9 enters the drum cavity.

FIG. 3 shows details of the movable core 13 of the electromagnetic yarn stopping device 8 according to the present invention. The core 13 has a substantially cylindrical hollow head 15 made of a ferromagnetic material capable of responding to the action of the electromagnetic coil 12.
And a rod 9 made of a ceramic material having high wear resistance. The rod 9 protrudes in the head 15 so as to be immovable in the axial direction.

According to the invention, the ceramic rod 9 is fixed to the head 15 and blocked by injecting a suitable synthetic plastic material 16 into the hollow between the head and the rod. To ensure this connection, grooves 17, 17A and grooves 18, 18A are formed in the outer surface of the rod 9 and the inner surface of the head 15, respectively, so as to create an undercut penetrating the injected plastic material, 9
This significantly improves the grip between the two.

The two grooves 17, 17A formed in the rod portion accommodated in the head 15 are not aligned with the grooves 18, 18A of the head but are shifted in the axial direction. The projecting free end of the rod 9 is provided with a rounded tip, and the movable core 13
The coil 12 is retracted into the rest position so that when the weft 4 is to be supplied to the loom again for a new insertion, it can be immediately removed from the weft 4.

As is known in the weaving art, ceramic materials have previously been stuck to heads of ferromagnetic material because of their excellent resistance to abrasion caused by the rubbing of yarns, especially yarns sliding over narrow surfaces. The rod 9 of ceramic material, which has not been employed due to the difficulty of forming the rotating core of the device by means of this device, significantly improves the durability and reliability of the thread stop. Further, firmly and safely fixing the rod 9 to the head 15 eliminates the possibility that such a material having low mechanical strength, for example, a ceramic material, is damaged by vibration, periodic motion, or impact. Such sticking also allows the rod to protrude from the core, effectively countering the inertial forces determined by the moving core moving at high speed.

FIGS. 4 to 6 show the yarn stopping device 8 in an activated state in which the rod 9 penetrates a cavity 10 provided in the drum 3.

According to the present invention, the cavity 10 includes the drum 3
The cavity 10 is formed as a wide slit extending along a quasi line of the drum peripheral surface, and the cavity 10 is provided with walls 21 and 22 which are positioned according to the drum generatrix and which expand and incline outward from each other. This wall, as in the illustrated embodiment,
Although it is good to be constituted by a simple inclined flat surface, it can also be constituted by an inclined surface having a curved surface.

According to the cavity 10 of the above-described characteristic, when the drum 3 rotates around the drum axis (indicated by A in the drawing), the end of the rod 9 will have two inclined walls 21, 22 of the cavity 10. And generates a force component directed toward the axis of the rod 9. This component causes the lifting of the rod 9, which is facilitated by the rounded tip of the rod making smooth contact with the inclined wall.

Therefore, the wall of the cavity 10 does not prevent the rotation of the drum 3, does not have a practical impact, and has a gentle sliding contact that prevents the rod 9 from digging into the cavity 10. The end of the rod 9 is not damaged.

The construction of the other parts of the drum 3 allows the drum to be completely rotated about the drum axis.
The adjustable column 7 is inside the circle C about A in the maximum projecting position, and the free end of the rod 9 keeps the outside position of the circle C when projecting from the device 8, and thus There is no possibility of colliding with the adjustable column 7.

[0028]

These properties improve the reliability of the weft feeder and protect it from improper use, and are therefore highly felt by looms manufacturers and users, and are fragile rods such as ceramics such as the present invention. Equipped with an electromagnetic thread stopping device having a rod can solve a serious problem.

[Brief description of the drawings]

FIG. 1 is a side view of a partial cross section of a measuring weft feeder having an improved portion according to the present invention.

FIG. 2 is a longitudinal sectional view of a normal electromagnetic yarn stopping device of the weft feeder of FIG. 1;

FIG. 3 is a side view, partially in section, of a movable core according to the invention for the electromagnetic thread stopping device of FIG. 2;

FIG. 4 is a front view of the weft feeder shown in FIG. 1 as viewed from an end on the outlet side.

FIG. 5 is a side view of the weft feeder drum of FIG. 1 as viewed from the yarn stopping device side.

FIG. 6 is a reduced perspective view of the weft feeder according to the present invention as viewed from an outlet end thereof.

[Explanation of symbols]

 Reference Signs List 1 electric motor 2 winding arm 3 drum 4 weft 5 reserve 6 sensor 7 column 8 electromagnetic device 9 rod 10 cavity 11 body 12 electromagnetic coil 13 movable core 14 spring 15 hollow head 16 synthetic plastic material 17, 17A, 18, 18A groove 21 , 22 walls

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) D03D 47/36 B65H 51/22

Claims (6)

(57) [Claims] 1. A measuring weft feeder for a fluid jet loom capable of measuring the length of a weft to be inserted into a loom shed, comprising: an electric motor for rotating a winding arm; A fixed drum wound as a winding portion forming a weft reserve whose length is controlled by a sensor, and an electromagnetic yarn stopping device, wherein the electromagnetic yarn stopping device receives at least one electromagnetic coil and an attraction action of the coil. A movable core made of a ferromagnetic material, a yarn stop rod provided on the movable core, and the yarn stop rod moved between a retreat rest position and a projecting yarn stop position so as to hook and stop the yarn at the outlet of the weft feeder. And a return spring adapted to be positioned at a position where the end of the rod is positioned in a cavity formed near the free end of the drum on the peripheral surface of the drum at the stop position of the projected yarn. In the metering weft feeder configured as described above, the movable core of the yarn stopping device is formed by a substantially cylindrical hollow head of ferromagnetic material and a cylindrical rod of ceramic material axially positioned inside the hollow of the head. A groove is formed on the outer surface of the rod and the inner surface of the hollow head along a quasi line of these surfaces, and a plastic material is injected and filled in a remaining space between the head and the rod, and the rod is filled with the rod. A measuring weft feeder that is fixed to the head. 2. The measuring weft feeder according to claim 1, wherein the grooves of the rod and the hollow head of the yarn stopping device are not aligned with each other when the two parts of the movable core are mounted. 3. The measuring weft feeder according to claim 1, wherein the projecting free end of the rod is rounded. 4. The drum free end receiving drum cavity wall of the yarn stopping device is positioned according to the generatrix of the drum, and these walls are inclined so as to expand outward from each other.
The weighing weft feeder as described. 5. The weft feeder according to claim 4, wherein the inclined wall of the drum cavity accommodating the rod end of the yarn stopping device has an inclined flat surface. 6. A drum according to claim 1, wherein said drum is provided with a column projecting from said cylindrical body so as to be adjustable. At a maximum projecting position of said column, said column exists inside a circle centered on a drum rotation axis. 5. The metering weft feeder according to claim 4, wherein the rod of the stopping device is always kept outside the circle.