Patent Description:
Generally in a circular knitting machine, tubularly knitted fabric manufactured by a knitting unit provided on an upper part of the knitting machine is rolled up by a take-up unit provided on a lower part of the knitting machine so as to be stored. Typically, the take-up unit sends the tubularly knitted fabric downward using a pull roller so that the tubularly knitted fabric is wound on a take-up roller and thus is collected as a roll.

There are various kinds of take-up rollers, and among them, there is a take-up roller having a configuration capable of being split in the middle thereof. Specifically, this type of take-up roller is split in the middle thereof in the longitudinal direction so that the respective split rollers are moved, by motive power, each in the opposite direction along the axis direction of the take-up roller. Thus, a space between the two split rollers is opened/closed. With this configuration, the take-up roller can be removed from a roll of knitted fabric rolled up thereon when the knitting is finished, which leads to easy operations after knitting such as carry-out of the knitted fabric. This split type take-up roller is often used in an auto-doffer type take-up unit that discharges the finished knitted fabric automatically from the inside of the circular knitting machine to the outside, as shown in Patent Document <NUM>.

Meanwhile, when the knitted fabric is rolled up on the take-up roller, the bigger the roll of knitted fabric becomes, the larger the pressure toward the center of the roll becomes due to increase in take-up tension of the knitted fabric and so forth. Sometimes the split type take-up roller is unintentionally split by this pressure, not by the motive power. If the take-up roller is thus split, the accuracy in rolling up is degraded. Also in the case where the split take-up rollers sandwich the knitted fabric as shown in Patent Document <NUM>, sandwiching of the knitted fabric loosens due to the split take-up rollers being separated from each other, which affects the rolling up of the knitted fabric.

In order to prevent the above unintentional split of the take-up roller, an invention is also disclosed, as shown in Patent Document <NUM>, in which the split take-up rollers are mechanically engaged with and connected to each other. <CIT> discloses a split-type roller according to the preamble of claim <NUM>. <CIT>, <CIT> and <CIT> each discloses discloses a split-type roller but no magnet or magnetic material.

However, due to recent development of the knitting machine with high-operation speed, the take-up unit also rotates at high speed, which occasionally causes an unintentional split of the split type take-up roller by centrifugal force. Sometimes, although the above-described pressure toward the center of the roll does not cause a big problem, this centrifugal force constrains the take-up roller to split from each other.

In order to deal with the above problem, by mechanically engaging with and thus connecting to the split rollers of the take-up roller as shown in Patent Document <NUM>, the unintentional split of the take-up roller can be prevented. However, such a take-up unit has a complicated configuration with a number of components. Furthermore, in the case where the take-up unit sandwiches the knitted fabric as shown in Patent Document <NUM>, it is difficult to adopt the configuration in Patent Document <NUM> in which the split rollers of the take-up roller directly make contact with each other to be mechanically engaged with each other, since the knitted fabric is interposed between the two split rollers of the take-up roller.

An object of the present invention is to provide a split type take-up roller of a take-up unit for a circular knitting machine. The split type take-up roller has a simple configuration which can also be applied to a take-up roller that sandwiches the knitted fabric, so that an unintentional split of the take-up roller due to centrifugal force caused by rotation of the take-up unit is prevented.

A split type take-up roller of a take-up unit for a circular knitting machine according to the present invention is a split type take-up roller of a take-up unit collecting knitted fabric knitted by a knitting unit of a circular knitting machine. The split type take-up roller is horizontally provided, and collects the knitted fabric by rolling up the knitted fabric thereon. The split type take-up roller includes: a first take-up roller and a second take-up roller made by splitting the split type take-up roller in a substantial middle thereof in a longitudinal direction; a first facing part that is a facing part of the first take-up roller so as to face the second take-up roller in a state in which the first take-up roller and the second take-up roller are engaged with each other; a second facing part that is a facing part of the second take-up roller so as to face the first facing part in the state in which the first take-up roller and the second take-up roller are engaged with each other; and a magnet provided on at least one of the first facing part and the second facing part so as to generate magnetic force to act on the other one.

With this configuration, the magnetic force acts on between the first take-up roller and the second take-up roller so as to attract them to each other. That is, the centrifugal force to separate them from each other is negated. The magnet is, for example, a permanent magnet that generates magnetic force. In the state in which the first take-up roller and the second take-up roller are connected to each other without splitting, the magnet is provided on at least one of the first facing part and the second facing part, at a position from which the magnetic force reaches the other one. The magnet may also be built in the facing part, apart from provided on the surface thereof. Thus, the first facing part and the second facing part face each other, and furthermore one of them is provided with the magnet while the other of them is a part (magnetic material) on which the magnetic force by the magnet acts. In this way, the magnet improves the force to connect the first take-up roller and the second take-up roller to each other. Therefore, the unintentional split of the first take-up roller and the second take-up roller due to the centrifugal force is prevented. Also, since no complicated connecting configuration is required, it is possible to reduce costs. Furthermore, since the magnetic force acts even when the knitted fabric or the like is interposed between the first take-up roller and the second take-up roller, this configuration can be applied to the take-up roller that sandwiches the knitted fabric.

It is preferable that the first take-up roller includes a convex part protruding toward the second take-up roller from a dividing surface that passes through a dividing position on an outer circumferential surface of the first take-up roller and the second take-up roller, and that the second take-up roller includes a concave part having a shape to house the convex part therein.

With this configuration, the take-up roller is constituted of the first take-up roller and the second take-up roller in which the convex part of the first take-up roller is fitted into the concave part of the second take-up roller. In this way, the first take-up roller and the second take-up roller are firmly engaged with each other, which prevents deformation of the take-up roller even when external force such as force in the direction perpendicular to the rotational axis of the take-up roller is applied. Thus, the first take-up roller and the second take-up roller can be rotated integrally as one roller having the same axis line as the rotational axis.

It is preferable that the convex part is constituted of at least one columnar member such as a sphere, a column, a cone and a frustum, and that the concave part is constituted of at least one columnar hole having a shape substantially complementarily to the at least one columnar member such that the convex part is inserted into the concave part. The shape of the columnar member also includes: a column; a cylinder; an elliptical column; an elliptical cylinder; a triangular prism; a quadrangular prism; a pentagonal prism; a hexagonal prism; and other polygonal prisms and polygonal tubes. Also, the columnar member may have a shape made by combining a plurality of shapes.

With this configuration, the convex part has a columnar shape such as a column, a cone and a frustum while the concave part is formed to house the convex part therein. Thus, the convex part and the concave part are firmly engaged with each other, and it is possible to prevent the take-up roller from becoming deformed even when the external force acts on the outer surface of the take-up roller.

Also, when using a type of unit in which the knitted fabric is sandwiched between the first take-up roller and the second take-up roller so as to fix the knitted fabric to a take-up roll, the first take-up roller and the second take-up roller are re-engaged with each other after a roll of knitted fabric is discharged from the take-up roller. Then, the knitting machine is rotated to some extent that knitted fabric is knitted down a little before the knitting machine is actually started to knit. After that, the first take-up roller and the second take-up roller are separated from each other to make a gap within the range in which the end of the convex part is not out of the concave part, so that the leading end of knitted fabric is inserted between the first take-up roller and the second take-up roller. Then, the convex part is re-inserted completely into the concave part. Thus, the leading end of the knitted fabric can be sandwiched between the first take-up roller and the second take-up roller without being inserted into the concave part. In other words, the position where the knitted fabric is sandwiched is different from the position where the first take-up roller and the second take-up roller are attracted to each other by the magnetic force. In this way, the knitted fabric can be sandwiched without preventing the engagement of the first take-up roller with the second take-up roller due to the interposition of the knitted fabric, which results in firm connection of the first take-up roller to the second take-up roller. Thus, it is possible to reliably realize auto-doffing, i.e. performing automatically unloading and discharge of a roll of knitted fabric from a machine to the outside without manual work so as to start a next knitting.

It is preferable that, in a state in which the split type take-up roller is not split, the first facing part is disposed on an end of the convex part at the side of the second take-up roller, and the magnet is provided on at least a part of a surface of the second facing part or on a part inside the second facing part.

With this configuration, the first facing part is attracted to the side of the second take-up roller because the magnetic force of the magnet acts on the end of the convex part at the side of the second take-up roller. In this way, the magnetic force acts only after the convex part is completely engaged with the concave part, which means that no magnetic force is generated in the engaging process. Thus, the operation process of the take-up unit is not likely to be affected by, for example, occurrence of attraction of tools such as a wrench to the magnet or function of unnecessary force derived from the magnetic force. Also, since the magnet is not provided on the first facing part, the magnet is not broken even when the convex part collides with somewhere.

The present invention provides a split type take-up roller of a take-up unit for a circular knitting machine. This split type take-up roller has a configuration in which a first take-up roller and a second take-up roller separated from each other are attracted to each other by magnetic force caused by a magnet, which cancels out separating force caused by centrifugal force and acting on dividing parts of the take-up roller. Thus, the dividing parts are not separated from each other. Also, since the split type take-up roller has a simple configuration compared to a configuration in which the first take-up roller and the second take-up roller are mechanically engaged with each other directly to prevent separation, it is possible to reduce the number of components.

<FIG> is a front view illustrating an entire circular knitting machine <NUM> including a take-up unit <NUM> for a circular knitting machine, which has a split type take-up roller of the present invention. Similarly to a general take-up unit for a circular knitting machine, the take-up unit <NUM> is a unit in which knitted fabric manufactured by a knitting unit <NUM> provided on an upper part of the circular knitting machine <NUM> is pulled by a pull roller <NUM> provided on an upper part of the take-up unit <NUM> so that the knitted fabric is rolled up on a take-up roller <NUM> and thus is collected.

The take-up roller <NUM> has a one columnar shape constituted of a first take-up roller <NUM> and a second take-up roller <NUM>. An outer circumferential surface of the take-up roller <NUM> is separable to the first take-up roller <NUM> and the second take-up roller <NUM> at an approximately middle part in the longitudinal direction of the take-up roller <NUM> (i.e. in the horizontal direction when the take-up roller <NUM> is installed). The outer circumferential surface of the take-up roller <NUM> is divided at a dividing position along a cross section perpendicular to the rotational axis and to the longitudinal direction.

<FIG> is a cross-sectional view illustrating a convex part <NUM> and a concave part <NUM> of the split type take-up roller <NUM> according to embodiment <NUM> of the present invention. A column-shaped convex part protrudes from a dividing surface of the first take-up roller <NUM> of the take-up roller <NUM> toward the second take-up roller <NUM>. That is, the first take-up roller <NUM> has the convex part <NUM> that protrudes toward the second take-up roller <NUM>. A first facing part <NUM> is disposed on an end of the column-shaped convex part <NUM> at the side of the second take-up roller <NUM>. A second facing part <NUM> disposed on a bottom end of the concave part of the second take-up roller <NUM> faces the first facing part <NUM>. Thus, the flat surface of the first facing part <NUM>, which is located at the side of the second facing part, faces the flat surface of the second facing part <NUM>, which is located at the side of the first facing part. A disc-shaped permanent magnet is provided on the second facing part <NUM> as a magnet <NUM>. In order to prevent the end of the convex part <NUM> from directly making contact with and thus damaging the permanent magnet <NUM>, there is still a small gap of approximately <NUM> between the end of the convex part <NUM> and the permanent magnet <NUM> even when the respective dividing surfaces of the take-up rollers <NUM> and <NUM> come into contact with each other. This gap may be larger depending on the strength of the magnet, however, it is preferable to have a gap of at least <NUM> for the purpose of preventing the contact with the convex part <NUM>. The permanent magnet <NUM> generates force to attract the first facing part <NUM> by magnetic force. The strength of the magnetic force of the permanent magnet <NUM> is set to be necessary and sufficient to negate the centrifugal force that separates the first take-up roller <NUM> and the second take-up roller <NUM> when the circular knitting machine <NUM> is in operation.

In this way, it is possible to cancel and negate the force that is generated by the centrifugal force of the entire take-up unit and that acts on the dividing position of the take-up roller <NUM> in the opposite direction in the rotational axis direction. Also, the second take-up roller <NUM> has the concave part <NUM> that is a recess having a shape for housing the convex part <NUM> so that the convex part <NUM> is firmly engaged with the concave part <NUM>. Thus, even when the force perpendicular to the rotational axis of the take-up roller <NUM> acts on the take-up roller <NUM>, it is possible to prevent the take-up roller <NUM> from being bent in the middle thereof or becoming deformed.

When this embodiment is applied to a type of unit in which the leading end of the knitted fabric is sandwiched between the first take-up roller <NUM> and the second take-up roller <NUM> so that the knitted fabric is rolled up on a take-up roll by rotating the take-up roller <NUM>, the knitting machine is rotated to some extent that knitted fabric is knitted down a little in the state in which the take-up roller <NUM> is not divided before the knitting machine is actually started to knit. After that, the first take-up roller <NUM> and the second take-up roller <NUM> are separated from each other to make a gap within the range that the end of the convex part is not out of the concave part to exceed the position of the dividing cross section of the take-up roller <NUM>, so that the leading end of knitted fabric is inserted between the first take-up roller <NUM> and the second take-up roller <NUM>. Then, the convex part <NUM> is completely inserted into the concave part <NUM>. Thus, the knitted fabric can be sandwiched between the first take-up roller <NUM> and the second take-up roller <NUM> without being inserted into the concave part <NUM>. In other words, the position where the knitted fabric is sandwiched is different from the position where the first take-up roller <NUM> and the second take-up roller <NUM> are attracted to each other by the magnetic force.

In this way, the knitted fabric can be sandwiched without preventing the engagement of the first take-up roller <NUM> with the second take-up roller <NUM> due to the interposition of the knitted fabric. Thus, it is possible to reliably realize auto-doffing, i.e. performing automatically unloading and discharge of a roll of knitted fabric from a machine to the outside without manual work so as to start a next knitting.

<FIG> is a cross-sectional view illustrating the convex part <NUM> and the concave part <NUM> of the split type take-up roller <NUM> according to embodiment <NUM> of the present invention. In this embodiment, the convex part <NUM> has a shape of a quadrangular prism, and the first facing part <NUM> is a side surface of the end part of the quadrangular prism at the side of the second roller <NUM>. The second facing part <NUM>, which faces the first facing part <NUM>, surrounds the first facing part <NUM>. A ring-shaped permanent magnet is provided so as to be an inner surface of the second facing part <NUM>. In this embodiment, there is no permanent magnet in front of the motion trajectory of the convex part <NUM> in contrast to embodiment <NUM>. Thus, the end of the convex part <NUM> is not likely to collide with the permanent magnet.

<FIG> is a cross-sectional view illustrating the convex part <NUM> and the concave part <NUM> of the split type take-up roller <NUM> according to embodiment <NUM> of the present invention. <FIG> is a diagram of the first take-up roller <NUM> according to embodiment <NUM> of the present invention, which is viewed from the second take-up roller <NUM> side. <FIG> is a diagram of the second take-up roller <NUM> according to embodiment <NUM> of the present invention, which is viewed from the first take-up roller <NUM> side.

In this embodiment, two column-shaped convex parts <NUM> are provided on the dividing surface of the first take-up roller <NUM> at regular intervals from the center rotational axis of the take-up roller <NUM>. The first facing part <NUM> includes a surface of the column-shaped convex part <NUM> at the side of the second take-up roller <NUM>. The second facing part <NUM> includes a surface that faces the surfaces of the column-shaped convex parts <NUM> at the side of the second take-up roller <NUM>. The concave part <NUM> has columnar holes each having an inner circumferential surface that comes into contact with the corresponding outer circumferential surface of the two column-shaped convex parts <NUM>. Between the inner circumferential surfaces, a wall is provided on the center of the hole so as to extend between the two column-shaped convex parts <NUM>. Thus, the wall comes into contact with the two column-shaped convex parts <NUM>. The bottom part of this wall is opened, and a disc-shaped permanent magnet is provided on the second facing part <NUM> through the opened bottom part of the wall. That is, the disc-shaped permanent magnet covers the surface that faces the surfaces of the two column-shaped convex parts <NUM> at the side of the second take-up roller <NUM>. Therefore in this embodiment, the convex part is engaged with and thus positioned relative to the concave part in the rotating direction of the take-up roller <NUM>. In this way, it is possible to prevent deviation of the first take-up roller <NUM> and the second take-up roller <NUM> from each other in the rotating direction due to the force caused by rotation of the take-up roller <NUM>.

The present invention is not limited to the above embodiments but only by the scope of the claims. That is, the take-up roller <NUM> is rotated by the motive power caused by the motor in the above embodiments, however, the take-up roller <NUM> may be used to other types of take-up units, which include a friction type take-up unit in which a friction roller is rotated in place of the take-up roller <NUM> and this friction roller comes into contact with the knitted fabric rolled up on the take-up roller <NUM> so as to rotate, by rotational friction, the take-up roller <NUM> with the knitted fabric being rolled up thereon.

Claim 1:
A split type take-up roller of a take-up unit (<NUM>) collecting knitted fabric knitted by a knitting unit (<NUM>) of a circular knitting machine (<NUM>), the split type take-up roller being horizontally provided, and collecting the knitted fabric by rolling up the knitted fabric thereon,
the split type take-up roller further comprising
a first take-up roller (<NUM>) and a second take-up roller (<NUM>) made by splitting the split type take-up roller in a substantial middle thereof in a longitudinal direction;
a first facing part (<NUM>) being a facing part of the first take-up roller (<NUM>) so as to face the second take-up roller (<NUM>) in a state in which the first take-up roller (<NUM>) and the second take-up roller (<NUM>) are engaged with each other;
a second facing part (<NUM>) being a facing part of the second take-up roller (<NUM>) so as to face the first facing part (<NUM>) in the state in which the first take-up roller (<NUM>) and the second take-up roller (<NUM>) are engaged with each other;
the split type take-up roller being characterized by further comprising:
a magnet (<NUM>) provided on at least one of the first facing part (<NUM>) and the second facing part (<NUM>); and
a magnetic material on which magnetic force of the magnet acts, the magnetic material forming at least a part of the other one of the first facing part (<NUM>) and the second facing part (<NUM>) on which the magnet (<NUM>) is provided.