GB2184753A - Introducing elastic thread in a double-cylinder circular knitting machine - Google Patents

Abstract

To ensure the safe introduction of an elastic thread under the hooks of knock-over sinkers 13 when knitting hosiery and the like goods in a double-cylinder circular knitting machine sinker cam rings 14, 15 of the machine are arranged to be angularly adjustable so that the clearing edge of the sinkers cam rings can get under the upper lowering cam 11 set in action during the supply of an elastic (rubber) thread. When elastic thread is supplied, e.g. to form a welt, the lowering cam 10 which is operative during normal knitting is withdrawn radially and the needles are lowered at a later point by cam 11. The cam rings 14, 15 are shifted at the same time, by a control drum, to shift the clearing edge of the cam rings from the point B below the normally-operative cam 10 to the point B' below cam 11. <IMAGE>

Description

SPECIFICATION A thread supply device in a double-cylinder circular knitting machine The present invention relates to a thread supply device in a double-cylinder circular knitting machine forthe safe supply of an elastic thread under the hooks of opened knock-over sinkers when knitting the welt of hosieryand the like goods,where in an upper needle cylinderthere are located before one stationary lowering cam serving to lowerthe needles into a clearing position, two radially shiftable lowering cams following said stationary lowering cam.

It is known in double-cylinder circular knitting machines when supplying the elastic (rubber) thread when knitting the welt on upper and lower needles for sliding of said thread overthe hookofthe upper needle to take place. This happens because the rubber thread is supplied differently as compared with the remaining threads so that it crosses the needle arch substantially only behind the place where the needles clearthe non-rubberthread. In this position the knock-over sinkers are already closed and therefore when the upper needles or their heads pass the knock-over level, the rubberthread can slide over said heads.

It is an object of the present invention to obviate or eliminate the above mentioned disadvantage.

According to the present invention there is provided a devicein a double-cylindercircularknitting machine forthe safe supply of an elasticthread underthe hooks of opened knock-over sinkers when knitting the welt of hosiery and the like goods, wherein an upper needle cylinderthere are before one stationary lowering cam serving to lower the needles into a clearing position, two radially shiftable lowering cams following the said stationary lowering cam, sinker cam rings being provided to control knock-over sinkers arranged shiftably by a predetermined value H corresponding essentially to the distance between said radially shiftable lowering cams so asto move the clearing edges of the sinker cam ring under said shiftable lowering cams.

The advantage ofthe present invention is that motion ofthe sinker rings ensures clearing ofthe rubber (elastic) thread by knock-oversinkers and eliminates sliding over ofthe rubberthread.

An embodiment of the present invention will now be described byway of example with reference to the accompanying drawings, wherein: Fig. 1 illustrates part of a cam system to control lower and upper needle guiding jacks with illustrated position of a knock-oversinker ring in a doublecylinder circular knitting machine.

Fig. 2 is schematic illustration of the knock-over sinker ring control buy a control drum; and Fig. 3 is a schematic illustration ofthe position and course ofthe threads and knock-over sinkers with normal and turned position of the knock-over sinker rings.

Referring to the drawings, a known double-cylinder circular knitting machine for the production of hosiery goods is provided with upper and lower needle cylinder 1,2 in the trick of which there are located upper and [ower guiding jacks 3,4 ofthe needles 5 and furtherjacks 6. Only the cams ofthe knitting feed to control the guiding jacks 3, 4 coherent with the supply of the elastic (rubber) thread into the needles5 are illustrated,foran understanding ofthe invention. In the cam m system af cam systemofthelowerneedlecylinder2there are provided a central cam 6, a stitch cam 7, and a raising cam 8.In the cam system of the upper needle cylinder 1 there are provided a stitch cam 9 and a following lowering cam 10 which is radially shiftable and lowers the needles 5to the level of a stationary lowering cam 12. Further behind the lowering cam 10 there is arranged a radially shiftable lowering cam 11 after which follows said stationary lowering cam 12 to lower the needles into the clearing position.

Knock-oversinkers 13 controlled by the sinker cam rings 14 and 15 being mounted in a known way on a tube 16 (Fig. 2) located angularly swingably inside the lower needle cylinder 2 cooperate with needles 5.

Horizontally arranged tie-rod 17 is fixed by a pin to the lower end of the tube 16, the other end of said tie-rod being mounted on a vertically arranged lever'18 mounted on pin 19 in a machine frame (notshown).

The lever 18 is in contact by its nose 18 with the control drum 19.

The operation of the above described device is as follows. When knitting a hosiery fabric, knitting begins with aweltwhich is knitted on upper and lower needles, eg. in 1:1 setoutin one knitting feed, where the thread guide 20 (Fig. 3) suppliesthethread Pinto the needles 5 and the elastic thread guide 21 supplies the elastic thread 6. The control drum 19 is in the position wherethefollower nose 18 of the lever 18 bears against its cam segment 22. The lever 1 8turns thetube 16 by means ofthetie-rod 17 and thusalsothe sinker cam rings 14 and 15 in the direction of rotation ofthe needle cylinders 1 and 2 by an anglevalue H.

Said distance H corresponds basically to a motion of point B, i.e. ofthe beginning ofthe clearing edge ofthe upper sinker cam ring 15 in theoriginal position into the position B as illustrated in Fig. 1. Said points B and B are located under the lowering cam 10, or under the lowering cam 11. When knitting the welt and when supplying the elastic thread 6, the radially shiftable lowering cam 10 is out of action while the radially shiftable lowering cam 11 operates. That is the needles 5 in the upper needle cyZinder 1 begin to be lowered later than during normal knitting, that means on the lowering cam 10.However becausethesinker cam rings 14and 15areturned inthedirection of rotation by the distance H, elastic thread 6 gets into the opened hooks of the knock-over sinkers 13, the track of which is marked by a dashed line as compared with a full track D as occurs during normal knitting, so th at thetrackD ensures supply ofthe elastic th read 6 together with th rea d 7 underthe hook of the upper needle 5.

After supply of elastic thread 6 is complete, or after putting the thread guide 21 out of action, the control drum 19 indexes. The nose 18 drives down from the cam segment 22 and the lever 18 andtie-rod 17 return the tube 16, orthesinkercam rings 14and 1 5intothe original positions, ie. against the direction of the needle cylinder rotation.

Claims (3)

1. I. A device in a double-cylinder circular knitting mach ine for the safe supply of an elastic th read under the hooks of opened knock-over sinkers when knitting the welt of hosiery and the like goods, where in an upper needle cylinderthere are before one stationary lowering cam serving to lower the needles into a clearing position, two radiallyshiftable lowering cams following the said stationary lowering cam, sinker cam rings being provided to control knock-over sinkers arranged shiftably by a predetermined value H corresponding essentially to the distance between said radially shiftable lowering cams so as to move the clearing edges ofthesinkercam ring under said shiftable lowering cams.
2. 2. A device as claimed in claim 1,whereinthe sinkercam rings are arranged on a tube being arranged angularly movable inside a lower needle cylinderwhile atie-rod is fixed to the lower end ofthe tube, said tie-rod being associated with a swingable lever having a follower nosewhich bears against the control drum.
3. 3. A device in a double-cylinder circular knitting machineforthe safe supply of an elasticthread under the hooks of opened knock-over sinkers, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.