US3548766A

US3548766A - Tufting machines

Info

Publication number: US3548766A
Application number: US781373A
Authority: US
Inventors: Clifford Colbert
Original assignee: Singer-Cobble Ltd
Current assignee: Singer-Cobble Ltd
Priority date: 1968-11-21
Filing date: 1968-12-05
Publication date: 1970-12-22
Anticipated expiration: 1987-12-22

Description

United States Patent 2,707,446 5/1955 McCutchen 1 12/79 2,818,037 12/1957 McNutt 112/79 2,840,019 6/1958 Beasley 112/79 3,006,296 10/1961 Penman... 1 12/79.6 3,221,682 12/1965 Burne1l.... 1 12/79 3,380,414 4/1968 Gray 112/79 3,442,233 5/1969 Card 1 12/79 Primary Examiner-Jordan Franklin Assistant Examiner-George V. Larkin Attorneys-Marshall J. Breen, Chester A. Williams and Julian Falk ABSTRACT: In order to minimise or eliminate stopmarking in a tufted product during the manufacture thereof on a tufting machine it is proposed to provide an auxiliary drive means whereby the puller rolls may be driven independently of machine operation during periods of machine stoppage to keep the yarn under tension and avoid withdrawal or retraction thereof.

PATENTEDUECZZIHYU 3,548,766

' SHEET 1 0F 2 INVENT Clifford Colbert ATTORNEY rur'rmc MACHINES The invention concerns tufting machines and has more particular reference to an attachment therefor whereby the incidence of stop marking is reduced.

Prolonged stoppage of a tufting machine, which stoppage may be due to one of several operational reasons, may, depending upon the type of pile yarn concerned, give rise to a withdrawal of yarn from loops or tufts already formed in a backing fabric with the result that a line of tufts each of a reduced height relative to the intended height will be present in the finished product and as a fault therein. The problem is of particular importance if the pile yarn is a bulked filament yarn since, on machine stoppage, the yarn present between the tufting needles and the next adjacent point at which the yarn is positively held retracts, and thus draws yarn from the last inserted loops.

The primary object of the present invention is to provide a means whereby the incidence of marking is reduced or the effects thereof minimised.

According to the present invention a tufting machine has a first yarn feed means actuablc to supply yarn at a required rate according to a predetermined sequence, and a second yarn feed means spaced therefrom in the direction of yarn feed and from which the yarns pass to the tuftingneedles, the first and second said means normally being operable in synchronism with the tufting machine operation to supply yarn to the tufting machine, and an auxiliary drive adapted independently of machine operation to drive the said second feed means and thus to maintain a tension in the yarn between the first and second feed means therefor and to prevent reverse motion of the yarn at the said second feed means.

The invention will now be described further, by way of example only, with reference to the accompanying drawings which illustrate one embodiment thereof and in which:

FIG. 1 is a diagrammatic side elevation of a tufting machine embodying the invention; p

FIG. 2 is a front elevation of one end of the machine shown in FIG. 1; and 7 FIG. 3 is a cross section taken throughthe freewheel arrangement in the drive transmission of the puller rolls.

Thus, referring now to the drawings, and particularly to FIG. 1 thereof, each pile yarn 11 passes from a creel (not shown) around the driven rollers 12a of a patterning attachment 12, through a tube element 13a of a tube bank 13, thence to a pair of puller rolls l4, and on to the tufting machine needles l5.

The feed of yarn is controlled by the rollers 12a of the patterning attachment in known manner, a quantity of yarn sufficient for the formation of a loop, or a lesser quantity of yarn as appropriate, being delivered to the needle at each machine cycle, according to pattern requirements.

The puller rolls 14 are of the kind disclosed in prior British Patent Specification No. 916,937 and comprise a pair of corrugated rolls having intenneshing teeth of uniform depth between which the yarn passes. The rolls are so spaced from each other that the clearance between the crests and the roots of the interrneshing teeth is greater than the thickness of the yarn so as to allow slippage of the yarn, and one of the rolls is normally driven at a speed greater than that at which yarn is fed to the pair of rolls.

The patterning attachment 12a and the puller rolls 14 are driven from the main shaft 16 of the tufiing machine in the usual way and thus their motion is dependent upon the motion of such main shaft. Any stoppage of the mainshaft, that is to say of the tufting machine, is accompanied by a stoppage of the patterning attachment and of the puller rolls.

In accordance with the present invention the puller rolls are provided also with an auxiliary drive means l7-independent of the main shaft 16 and adapted to beoperable to drive the puller rolls 14 on machine stoppage. The auxiliary drive means 17 is best shown in FIGS. 1 and 2 and will be seen to comprise an auxiliary drive motor 18, an auxiliary shaft 19 to ranged in spaced parallel disposition relative to the main shah 16, a sprocket 20 carried on the auxiliary shafl, a free wheel assembly 21 mounted on the main shaft, and

drive chains

22, 23 between the sprocket 20 and the free wheel assembly 21 and between such assembly 21 and a sprocket on the puller rolls 14 respectively.

Sprocket 20 on the auxiliary shaft 19 is coupled to the shaft through a conventional unidirectional clutch arranged to allow such sprocket to overrun the shaft when necessary.

The free wheel assembly 21, see particularly FIG. 3, comprises coaxially arranged inner and outer elements 21a, 21b having roller wedges 21c therebetween, the inner such element being keyed to the main shah, as at 24, and the outer element carrying spaced sprockets 25, 26 arranged respectively to engage the

drive chains

22, 23. The free wheel assembly is adapted and arranged to transmit a drive from the main shaft 16 to the outer element 21b on motion of the former in the forward drive direction thereof and to permit of a motion of the outer element in such forward direction relative to the inner element, in a manner well known, a wedging action of the roller edges relative to inner and outer elements ensuring the drive transmission when appropriate.

A drive is applied to the main shaft 16 from a main drive motor 27 via driving chains or belts 28, such chains or belts extending around

sprockets

29, 30 secured respectively to the output shaft 31 of the motor 27 and the said main shaft.

In operation, upon machine stoppage the auxiliary drive means 17 is actuated and the puller rolls 14 are caused to con tinue to rotate to draw the yarn ll forwardly from the patterning attachment 12, the drive transmission being from auxiliary motor 18 via the auxiliary shaft 19 to sprocket 20 and then to the outer element 21b of the free wheel assembly. From such outer element the drive passes to the puller rolls via chain 23. As, upon machine stoppage, the yarn is effectively stopped at the patterning attachment 12, the puller rolls 14, which rolls continue to rotate due to the drive from the auxiliary means, merely slip on the yarn thereby maintaining such yarn under tension and preventing the retraction of the yarn beyond the puller rolls in a direction against the direction of feed of the yarn. Any retraction of the yarn is a retraction of the length of yarn between the puller rolls and the needles, and having regard to the comparatively short length of yarn involved the amount of retraction, and thus the extent of withdrawal, is small.

During normal machine operation the auxiliary drive motor will be ineffective in driving the puller rolls, the drive trans mission from the main drive motor to the puller rolls being through the free wheel assembly, sprocket '20 overrunning the shaft on which it is supported. Whilst it may well be found convenient to arrange that the auxiliary motor will be switched on only on machine stoppage, in some circumstances it may be found preferable to have the auxiliary motor rotate continuously so long as the speed thereof does not exceed that of the main drive motor.

If desired, the conventional yarn jerker assembly can be modified to reduce the yarn path length between the puller rolls and the needles. By following this particular course, the possibility of any yarn withdrawal such as might occur on machine stoppage manifesting itself as a fault in the finished product is reduced or even eliminated. The modification of the yarn jerker is simple and will usually involve making collapsible the fixed part of such jerker, the said part, for example, being mounted on air cylinders or by a mechanical linkage to achieve this purpose.

A tufting machine having a yarn jerker modified as above will be provided with a prepositioned stop device to ensure that the needle bar and jerker always come to rest in the same position. i

The invention is not restricted to the exact features of the embodiment hereinbefore described since alternatives will readily present themselves to one skilled in the art. Thus, for example, the puller rolls may be replaced by an equivalent structure intended to achieve a forwarding of the yarn from a which the output of the said motor is coupled and which is aryarn feed means.

I claim:

1. A tufting machine including needles operable for penetrating a base fabric to form a pile and yarn feed means for feeding yarn to said needles, said yarn feed means including a first .yarn feed means actuable to supply yarn at a required rate in accordance with a predetermined sequence, a second yarn feed means spaced from said first yarn feed means in thedirection of yarn feed and from which the yarns pass to said needles, said first and second yam feed means being operable in synchronism with said tufting machine to supply yarn to said tufting machine, and auxiliary drive means operable independently of the main drive means of said tufizing machine for driving said second yarn feed means to maintain a tension in the yarn between said first and second yarn feed means and to prevent reverse motion of the yarn at said second yarn feed means.

2. A tufting machine as claimed in claim 1, further characterized by an unidirectional coupling member in the transmission of the auxiliary drive means adapted to allow the second yarn feed means to overrun the auxiliary drive means when the latter is inoperative.

3. A tufting machine as claimed in claim 2 wherein the auxiliary drivemeans comprises a drive motor, an auxiliary shaft drivingly connected to such motor for rotation thereby, a freewheel assembly mounted on the machine main shah and coupled thereto, the unidirectional coupling member being on the auxiliary shaft, a drive transmissionmeans between the said coupling member and the freewheel assembly, and a further drive transmission means between such assembly and the second feed means, the freewheel assembly including an inner element rotatable with the main shah, an outer element arranged coaxially with the inner element and radially outwardly thereof, roller wedges disposed between the inner and outer elements, and input and output sprockets on the said outer element, the said input sprocket receiving the first drive transmission means aforesaid and the said output sprocket receiving the said further drive transmission means, the whole being adapted and arranged to transmit a drive from the drive shaft to the output sprocket or from the auxiliary motor to such sprocket according to whichever is the higher of the auxiliary drive and main drive speeds.

4. A tufting machine as claimed in claim 1 wherein the second yarn feed means comprises a pair of cooperating corrugated rolls between which the yarns pass.