GB2109016A - A knitwork winding device in rotary cylinder circular knitting machines - Google Patents

Abstract

The device comprises a knitwork winding roller (16) arranged with its axis coincident with the machine axis, and being carried rotatably on the machine bed. Along the path followed by the knitwork (5) between the needle cylinder (3) and winding roller (16), knitwork guiding means (9, 10, 13) are arranged which set the knitwork (5) vertically along the width direction and rotate about the axis of the winding roller (16). Thus, the roller (16) is rotatively entrained by the knitwork (5) itself, albeit at a lower speed, the knitwork (5) being progressively wound around the roller (16). <IMAGE>

Description

SPECIFICATION A knitwork winding device for rotary cylinder circular knitting machines This invention relates to a knitwork winding device in a rotary cylinder circular knitting machine.

On knitting machines equipped with a knitwork winding device, in general large diameter machines, the winding device comprises a winding roller arranged across the machine axis at the lower portion of the same and being rotatively drive to wind up the knitwork as this is being knitted and allowed to drop through the machine.

On rotary cylinder machines, the roller is, of course, to rotate together with the knitwork or fabric about the machine axis, and is accordingly carried on the rotary structure of the machine.

To avoid frequent stopping of the machine, as well as for the knitting operations that follow, it is necessary for the roller with the knitwork wound around it to grow to a large overall size. This requires appropriate holders for supporting the roller and its related controls, and involves a substantial increase of the machine rotating mass, thus prejudicing stopping and starting. The arrangement itself of the roller, especially if the latter has considerably large dimensions when wound with the knitwork, makes it difficult to replace the roller after the winding step has been completed, it being necessary each time to lift the roller at its end in order to remove it from its supports.

This invention sets out to overcome the aforesaid drawbacks of conventional devices by providing a knitwork winding device for a rotary cylinder circular knitting machine, which allows the rotary structure to be released from the roller and wound knitwork support, while making replacement of the completely wound roller easier.

Within the above general aim, it can be arranged that the knitwork winding device of this invention requires no special drive means for rotating the roller as the knitwork is being wound, and allows the winding tension to be readily changed.

According to one aspect, this invention provides a knitwork winding device in a rotary cylinder circular knitting machine, comprising a knitwork winding roller located in the lower portion of the machine and driven to rotate such as to wind up the knitwork as the knitwork is being knitted and lowered through the machine, the knitwork winding roller being rotatable about the machine axis together with the knitwork, characterised in that the winding roller is arranged with its axis coinciding with the machine axis and is carried rotatably on the machine bed, and that along the path followed by the knitwork between the needle cylinder of the machine and the knitwork winding roller, there are provided knitwork guiding means rotating about the axis of the knitwork winding roller.

In a device of this type, the knitwork winding roller is no longer supported by the machine rotary portion, but rather by the fixed bed of the same, and rotates with the machine engaged with it through the knitwork. In fact, the roller is driven to rotate by the knitwork itself, which the guiding means continuously arrange about the roller axis at the same rotational speed as the machine.

Owing to the progressive formation of knitwork and to the roller weight and frictional resistances, however, the knitwork winding roller will follow the rotation of the guiding means at a lower speed, so that the knitwork is wound onto the roller simultaneously at the same rate as the knitwork output rate.

Advantageously, roller holdback means may be arranged to achieve a desired tension in the knitwork during the winding thereof. The rotating mass which must be driven by the machine main drive is, hence, much smaller, since the rotary portion is now to support just the knitwork guiding means, of modest mass. It follows that the problems attending the machine starting and stopping are eliminated, even in the instance of large size knitwork rolls.

Further features and advantages of the invention will be apparent from the following detailed description of a knitwork winding device according to the invention, as illustrated to exemplify a preferred embodiment and not by way of limitation in the accompanying drawings, where: Figure 1 is a partly sectional front view of a large diameter, rotary cylinder circular knitting machine incorporating a knitwork winding device of this invention.

Figure 2 is a side view of the device inside the machine of Figure 1; and Figure 3 is a perspective view of a part of the knitwork winding device intended to clarify the operation of the latter.

The large diameter circuit knitting machine shown in the drawings comprises a load-bearing frame 1, on which is rotatably mounted a rotary structure 2 which carries the needle cylinder 3 and is rotated in a manner known per se through a ring gear 4. The knitwork 5, which is produced in a tubular form by the needles 6, moves down to below the cylinder 2 under the tension applied by horizontal tensioning rollers 7. These are carried rotatably on two opposed side boards 8, rigid with the rotary structure 2, and are slowly rotated through conventional means, not shown and being foreign to this invention.

With the side boards 8, guiding means for the knitwork 5 are rigidly connected which comprise a first horizontal guide bar 9 located in the proximities of the tension rollers 7, and a second guide bar 10, located away from the bar 9 and arranged substantially at 45 in a vertical plane.

More specifically, the oblique bar 10 is carried at the top on an arm 11, made rigid with one of the side boards 8, and at the bottom on a frame 12, such as to extend over a distance from the axis of the machine and in the proximities of the walls of the load-bearing frame 1.

In the vertical plane of the oblique bar 10, there is arranged in the proximities of the bar lower end, a third vertical guide bar 1 3 which is supported at the bottom by the frame 12 and at the top by an arm 14 attached to a respective one of the side boards 8.

Preferably in a vertical plane forming a right angle with the plane containing the two guide bars 10 and 13, a fourth vertical guide bar 15 is provided, which is also supported by the frame 12.

Thus. the knitwork 5, as flattened by the tension rollers 7, is first deflected from the central area of the machine outwards, and then set vertically in the width direction; it is then conducted at a right angle and away from the machine axis, to be wound around a winding roller 1 6 located below the cylinder 3 with its axis coinciding with the machine axis and being rotatably supported on the fixed bed 17 of the machine.

More in detail, the winding roller 16 is inserted in a disk element 18 for rotation therewith, said disk element being supported rotatively on the bed 17 by means of a pivot pin 19 coaxial with the machine axis and being inserted through a hole in the bed 17. Between the latter and disk element 18, there is advantageously interposed a friction element 20.

The knitwork winding roller 1 6 is held in position at the top by a pin 21 arranged to penetrate the top end of the winding roller 16 and carried on a centering body 22. The body 22 is shiftable axially against the bias of an elastic means on a sleeve 23 fastened to a beam 24 which is rigidly connected to the side boards 8, so as to permit the withdrawal of the pin 21 from the winding roller 16.

It will be appreciated from the foregoing description that the structure defined by the guide bars 9, 10, 13 and 1 5 rotates along with the rotary structure 2, it being carried by the same, whilst the winding roller 1 6 is carried idle on the bed 1 7 of the machine, thereby it does not add to the weight of the rotary structure 2.

In operation, the guide bars 9, 10, 13 and 1 5 rotate about the axis of the winding roller 1 6 such as to lay the knitwork 5 around the roller itself.

However, since the rate of growth of the knitwork being knitted is small relatively to the rotational speed of the rotary structure 2, the knitwork 5 will rotatively entrain the winding roller 1 6 in the same direction of rotation as the rotary structure 2. Owing to the frictional resistances and weight of the winding roller 16 around which the knitwork 5 is wound, the roller is, however, held back, which allows the progressive winding of the knitwork 5 around the winding roller 1 6 while the latter is rotated. In other words, the winding roller 1 6 rotates at a lower speed than the machine, the differential being compensated for by the knitwork 5 winding und the winding roller 16.

Advantageously, it is possible to provide a brake 25 to hold the disk element 18 back to a larger or smaller extent, so that the winding tension of the knitwork 5 can be varied.

It will be appreciated that the vertical arrangement of the winding roller 1 6 not only relieves the rotary structure 2 of the weights of the roller and knitwork wound around it, but also facilitates the replacement of the roller with the knitwork wound on it, especially in the case of very large dimensions. Moreover, no special means are required to produce the rotation of the winding roller and wind up the knitwork.

The device as described is susceptible to modifications and variations within the scope of the invention. Thus, as an example, it would be possible to provide a motor arranged to act on the winding roller 1 6 in the knitwork winding direction, while retaining the arrangement of the roller and knitwork guiding means. It would also be possible to arrange the individual guide bars differently, while retaining the principle of winding the knitwork around a vertical axis roller. The invention, moreover, may be applied on both cylinder and dial machines and double cylinder machines and single cylinder machines.

Claims (6)

Claims

1. A knitwork winding device in a rotary cylinder circular knitting machine, comprising a knitworkwinding roller located in the lower portion of the machine and driven to rotate such as to wind up the knitwork as the knitwork is being knitted and lowered through the machine, the knitwork winding roller being rotatable about the machine axis together with the knitwork, characterised in that the winding roller is arranged with its axis coinciding with the machine axis and is carried rotatably on the machine bed, and that along the path followed by the knitwork between the needle cylinder of the machine and the knitwork winding roller, there are provided knitwork guiding means rotating about the axis of the knitwork winding roller.

2. A knitwork winding device according to Claim 1, characterised in that said knitwork guiding means are rigid for rotation with the machine rotary structure.

3. A knitwork winding device according to either Claim 1 or 2, characterised in that said knitwork guiding means comprise at least one guide bar arranged substantially at 450 in a vertical plane to deflect the knitwork, as flattened, into a vertical position in the width direction.

4. A knitwork winding device according to Claim 3, characterised in that said knitwork guiding means further comprise at least one additional guide bar, carried vertically on a frame rotating with the machine rotary structure and spaced apart from said guide bar substantially at 45ova

5. A knitwork winding device according to one or more of the preceding claims, characterised in that it comprises a brake for said winding roller.

6. A knitwork winding device for rotary cylinder circular knitting machines, substantially as herein described with reference to the accompanying drawings.