GB1564461A - Yarn supply apparatus eg for multi-feed knitting machines - Google Patents

Description

(54) YARN SUPPLY APPARATUS E.G. FOR MULTI-FEED KNITTING MACHINES (71) I, GUSTAV MEMMINGER, trading as GUSTAV MEMMINGER VERFAHRENSTECH- NIK FiiR DIE MASCHINENINDUSTRIE, a citizen of the Federal Republic of Germany, of Wittlensweiler Strasse 12, 7290 Freudenstadt, Federal Republic of Germany, do hereby declare the invention, for which I pray that a patent may be granted to me and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a yarn supply apparatus and more particularly to such an apparatus for multi-feed circular knitting machines.

Various types of yarn feed apparatus have been proposed; such apparatus is also known as Fournisseurs, in which feed drums having yarn looped thereabout are associated with respective feeds of a circular knitting machine. The drums themselves are driven by a single flat belt, which may be plastics or steel. The yarn is introduced between the belt and the circumferential sur face of the drum and, upon rotation of the belt, the yarn is continuously fed in the direction of movement of the belt. It has been found that it is difficult to provide slip-free feed particularly upon starting of the belt from stopped position. The drums have a certain inertia and some slip will result between the drums and the belt.It has been found desirable to construct the yarn supplied drums in the form of cages, that is, to place axially directed rods at the outer circumference of the drum, located between a pair of end discs. This permits increasing the pressure of the yarn at the inside of the belt in the region of circumferential engagement of the belt and the drum so that the undesirable slip between the yarn being supplied and the belt should be prevented. Still, it was not possible to provide slipfree feed of the yarn and to ensure that no slip between the yarn and the drum, or the belt occurs. The arrangement, additionally, has been found to cause difficulties and trouble if the yarn is of non-uniform quality, for example has slubs or the like.

According to the present invention there is provided yarn supply apparatus for textile machines comprising a plurality of freely rotatable yarn supply drums of the squirrel cage type, each yarn supply drum being adapted to be associated in use with a utilization position of a textile machine, means for guiding yarn to and from the drums, and a ribbed drive belt adapted to be coupled in use to a textile machine, the ribs of the drive belt facing the gaps between adjacent rods of each drum and engaging therein to press yarn into said gaps.

In operation of the apparatus of the present invention the ribs of the belt press the yarn in gaps between the rods forming the squirrel-cage-like supply drum. As a result, the yarn itself will assume a corrugated form with respect to a theoretical cylindrical surface forming the surface of rotation of the drum.

Additionally, the yarn will also be engaged by the ribs formed on the belt itself.

This permits, simply and effectively, to sub stantiallv increase the friction between the yarn and the drive element for the drum as well as the drum itself and particularly in the region of engagement of the drum and the belt. Slip of the yarn between the drum is thus excluded. Additionally, the drums can be driven by the ribbed belt by a positive drive so that, even upon starting, exact synchronism between the drums and the drive belt is ensured. The inertia of the drums thus can no longer cause difficulties with the yarn feed or introduce inaccuracies in feed or play a role in the entire startingoperation of the machine.

Under ordinary conditions, the yarn need be placed around the circumference of the supply roll, essentially, only in the zone in which the ribbed or toothed belt engages the supply drum. The arrangement can be so made, however, that the yarn is looped around the supply drum several times to form a storage winding thereon in order to provide for a yarn reserve in case of thread, or yarn breakage and thus prevent defects in the material being knitted or otherwise produced.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a schematic tcp view of a thread supply system for a circular knitting machine using the present invention Fig. 2 is a vertical fragmentary side view, partly in cross section taken along line II--II of Fig. 1, and to an enlargerd scale; Fig. 3 is a schematic representation of the drive belt and yarn supply drum, illustrating the operation. and taken along section line 111-111 of Fig. 2.

A circular knitting machine -- not further shown in detail - has a needle cylinder schematically indicated at 1. A carrier ring 2 for a plurality of yarn feed and storage drums 4 is secured to the frame of the knitting machine coaxially with respect to the cylinder 1, and attached thereto by spokes 3. Each feed of the knitting machine has a supply drum 4 associated therewith which, by means of suitable bearings, is freely rotatable about a vertical axis of rotation.

As best seen in Figs. 2 and 3, the supply drums 4 are formed as cages having two essentially parallel end discs 6, 7, spaced from each other and secured together by means of rods 5. This arrangement can be referred to as a "squirrel cane" supply drum, analogous to the terminology used in the electrical induction motors. The two end discs 6, 7 securing the rods 5 together are extended radially to form flanges 8, 9.

The drums are driven by an endless internally ribbed belt 10, guided around a portion of the circumference of each one of the drums 4 by suitable guide rollers 11, 12.

It is driven from a suitable drive motor, for example directly from the machine from a sprocket, or drive sheave 13. The sheave 13 can be coupled to the machine, for example by means of gearing, speed change arrangement which may be geared, or stepless, or the like.

The pitch, or distance of the ribs 111 of the belt 10 corresponds to the distance of the pins 5 on a drum 4 so that the teetht 111 will engage in the gaps between the pins 5 of any drum, as best seen in Fig. 3.

Two thread guide eyes 15, 16 guide the yarns 17 around the circumference of the drums. Eyes 15, 16 are suitably secured to the knitting machine, or to the drum structure, by suitable attachments (not shown) and as well known. The eye 15 supplies yarn 17 in the direction of the arrow to the circumference of the drum from a supply package, or pirn (not shown). the yarn being then deflected by the belt 10 upon movement of the belt 10 in the direction of the arrow 18 (Fig. 3). The yarn can then be removed from the supply drum 4 through eye 16. As clearly seen in Fig. 3, the yarn is pressed at least partially in the space between the rods 5 of the drum 4 and thereby corrugated around the circumference of the drum 4 so that the distance of engagement of the yarn with any of the rods 5 is greatly increased over the distance of engagement had the belt 10 only a smooth surface.The yarn 17 thus engages snugly both a portion of the circumference of the pins 5 as well as the ribs 111 of the belt 10.

The yarn removed through the eye 17 can then be conducted to a suitable utilization position, for example a feed of a circular knitting machine.

The yarn is reliably clamped between the ribs 111 and the gaps between the rods 5 by co-operation of the rods 5 of the drum 4 with the ribs 111 of the belt 10. Thus, in the region of engagement of the yarn with the drum 4, that is, over the limited circumferential extent thereof, the yarn is reliably and positively clamped to the drum and is supplied at a speed which corresponds to the linear speed of the belt 10, without slip.

The yarn could be supplied to the drum 4 as seen in Fig. 3 by supplying only in the region of engagement of the belt 10 with the rods 5 of the drum 4. As seen in Fig. 2, however, the yarn guide eyes can be so placed and the arrangement so made that the yarn is looped several times about the drum 4 before being removed through the eye 16. For this arrangement, the two eyes 15, 16, are axially staggered with respect to each other -- related to the axis of rotation of the drum so that the loops or windings on drum 4 will extend helically thereover.

The ribs 111 may have various shapes when looked at in profile; for example, as shown, the teeth can be trapeze shaped, or they can be so formed that they closely match the profile and shape of the circumference of the rods 5.

The deflection rollers 12 shown in Fig. 1 could be omitted. The belt 10 is then guided only around the outer portion of the drums 4. Since the belt 10 is in positive engagement with the drums 4, the circumferential engagement angle, or sector about each drum 4 can be small while still ensuring positive slip-free yarn feed. Ordinarily, an engagement region of a few ribs of the belt 10 is sufficient. The illustration of Fig. 3, in which the engagement angle of the belt about the drum is high has been shown to clearly illustrate the relationships upon engagement of the belt with the drum, with the yarn interposed therebetween, although such a large angle is usually not necessary and may be required only under special conditions.The very small angle of engage ment, or circumferential region of engagement between the belt 10 and the drum 4 is a principal advantage of the construction in accordance with the present invention.

Various changes and modifications may be made within the scope of the inventive concept as defined by the appended claims.

WHAT I CLAIM IS: 1. Yarn supply apparatus for textile machines comprising a plurality of freely rotatable yarn supply drums of the squirrel cage type, each yarn supply drum being adapted to be associated in use with a utilization position of a textile machine, means for guiding yarn to and from the drums, and a ribbed drive belt adapted to be coupled in use to a textile machine, the ribs of the drive belt facing the gaps between adjacent rods of each drum, and engaging therein to press yarn into said gaps.

2. Apparatus according to claim 1 wherein the ribs of the drive belt, in cross section, are substantially trapeze shaped.

3. Yarn supply apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. ment, or circumferential region of engagement between the belt 10 and the drum 4 is a principal advantage of the construction in accordance with the present invention. Various changes and modifications may be made within the scope of the inventive concept as defined by the appended claims. WHAT I CLAIM IS:

1. Yarn supply apparatus for textile machines comprising a plurality of freely rotatable yarn supply drums of the squirrel cage type, each yarn supply drum being adapted to be associated in use with a utilization position of a textile machine, means for guiding yarn to and from the drums, and a ribbed drive belt adapted to be coupled in use to a textile machine, the ribs of the drive belt facing the gaps between adjacent rods of each drum, and engaging therein to press yarn into said gaps.

2. Apparatus according to claim 1 wherein the ribs of the drive belt, in cross section, are substantially trapeze shaped.

3. Yarn supply apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.