GB2082208A

GB2082208A - A method for knitting socks

Info

Publication number: GB2082208A
Application number: GB8122075A
Authority: GB
Original assignee: British Bata Shoe Co Ltd
Current assignee: British Bata Shoe Co Ltd
Priority date: 1980-07-18
Filing date: 1981-07-17
Publication date: 1982-03-03
Also published as: NL8004144A

Abstract

A double cylinder circular knitting machine for knitting a string of interconnected workpieces such as socks joined by courses of weak separation yarn is characterized in that the take down rollers (17, 17') are adapted to be moved away from each other by the control drum (11) during knitting the separation yarn so that the take down force is reduced considerably, and that the means to hold the articles during the stroke of a ram (32) for breaking the separation courses consist of a flap (35) which is placed behind the ram in the direction of movement of the articles. One of the take down rollers (17) is mounted on a spring-biased lever (27) and is adapted to be moved against the force of a spring (28) by means of a cam (29) on the control drum (11). <IMAGE>

Description

SPECIFICATION A method for knitting socks The present invention relates to a method for knitting workpieces with a double cylinder circular knitting machine, which is provided with a device to draw off individual workpieces from a coherently knitted strand of workpieces, which are interconnected by separation stitches made with a weak separation yarn, said knitting machine consisting substantially of a needle cylinder and take down rollers, placed thereunder, which are controlled by a control chain and a control drum, the device to draw off the individual workpieces which is placed thereunder being equipped with a ram and with means to hold the articles during the stroke of the ram.

When socks are knitted with such a machine, the take down rollers rotate with the same speed as the cylinders during knitting the tubular portion of the sock, and the heel and toe thereof are stationary. The take down rollers make sure that the sock leaves the machine under the correct take-down tension so as to put the sock in a collector tray then. The take down tension provided by the take down rollers facilitates the uniform take down operation of the stitches from the needles and improves the uniformity of the stitch size.

Said take down tension is, however, so high, that three, four or more separation or so-called solvron yarns have to be used in the tweenknitting, i.e. the separation of the one sock at its band with the other sock at its toe, to thus prevent it from falling out and the like, before the separation by the draw off device can take place.

The separation yarn is in fact too weak to resist the take down tension when using a low number of such yarns, but Is made especially for this purpose to easily dissolve later on for instance in the dye-works, even at a submersion in merely water of 400 to 500C.

Another frequently occurring problem is the socalled cramming or twist of the sock in the exit pipe of the draw off device. This is caused by the fact that the upper flap of the draw off device is jammed and stands still while the knitting machine keeps on rotating.

For the draw off device works with an upper clamping device and a lower clamping device, between which the ram of the draw off device has to operate. The upper clamping device or upper flap holds the sock that the machine is knitting, while the lower clamping device or lower flap holds the already knitted and ready-to-be ejected sock.

So the clamping devices serve to hold the two socks and to prevent them from trailing along, so that the ram can function so as to sever the separation yarn. This twist has as a consequence that the needles and sliders in the cylinders cannot work any more and the machine stops, often with many broken needles and sliders.

The present invention tends to improve the known method such, that the take down tension no longer leads to the necessary use of relatively many, i.e. three or more so-called solvron yarns, whereas simultaneously the jamming or twist of the socks is prevented efficiently.

According to the invention this is achieved in that the take down rollers are adapted to be moved away from each other by the control drum during knitting the separation yarn so that the take-down force is reduced considerably, and that the means to hold the articles during the stroke of the ram consist of a flap which is placed behind the ram in the direction of movement of the articles.

A possible embodiment of a machine for the use of the above described method has as a characterizing feature that one of the take down rollers is mounted on a spring-biased lever and is adapted to be moved against the spring force by means of a cam on the control drum.

By the provision of said improvements one succeeded in reducing the take down tension temporarily and at the desired moment, namely during knitting said separation of the one sock at its band with the other sock at its toe. The take down force is relieved by at least 50% so that two solvron yarns permit an excellent knitting operation, and the connection between the two socks is made, but that it is so weak with the two yarns, that with the least force the take down device and the ram easily perform the separation.

Because of this it is also possible to leave the upper flap of the take-down device out, so that the jamming and twist can also be prevented.

The invention will be further elucidated hereinafter on the basis of the drawing, in which by way of example a machine is described for the application of the invented method. In the drawing is illustrated by: fig. 1 in perspective view a double cylinder knitting machine, and fig. 2 a schematic and partial view in the direction of the arrow Il of fig. 1.

In fig. 1 a section of a double cylinder circular knitting machine of a known type is illustrated which is used for knitting socks and the like articles. Reference will be made only to those components of the knitting machine, which are necessary for a good comprehension of the invention.

The machine consists of a frame 10, on which the control drum 11 for the knitting machine is mounted. Furthermore a support device is provided for a control chain 12, which circulates step-wise and affects the control drum 11 in the known manner, when this is necessary for the change in knitting cycle. During a circulation of the control chain 12 a knitting cycle is performed.

The frame is provided with an upper portion 1 3 with control drum 11 and also carries the (not illustrated) needle cylinder with control means and a pre-centering device with the pertaining control device.

At the leading side of the frame 10 two forwardly protruding supports are provided, one of which, indicated by reference numeral 14, is visible, and supporting a ring 15, on which the support device 1 6 for the usual take down rollers 1 7 and 1 7' under the rotatable needle cylinder, is rotatably supported.

A given length of a tubular knitting extends downwardly from the needle cylinder and is indicated by reference numeral 18. Said knitting is passed between the take down rollers 17 and 17', which take care of the necessary take down tension.

The support device 1 6, together with the take down rollers 1 7 and 17' are caused, in the known manner, to rotate simultaneously with the rotation of the needle cylinder, to complete the circular knitting. When at certain moments back-knitting is performed to form the heel and toe sections in the knitting 18, the rotation of the support device 16 with the take down rollers 1 7 and 17' stops.

The upper portion of the control chain 12 extends along a driven gear wheel 1 9, and the lower part extends about a gear wheel 20, which is mounted on a shaft, which at its turn is supported by a support section, mounted on the frame 10.

On an intermediate portion the control chain 12 extends up to a small gear wheel 21 on a shaft 22, which is mounted on the frame 10. The shaft 22 and the gearwheel 21 form the normal apparatus for adjusting the control chain 12 and for this purpose the shaft 22 is provided with a crank 23 which affects the shaft, so as to be able to rotate it manually.

Under the support 14 a feed pipe 24, a takedown device 25, and an exit pipe 26 are provided, in which a completed sock 8' is illustrated schematically.

The details which are important for the invention are illustrated best in fig. 2.

One of the take down rollers, namely take down roller 17', is fixedly arranged on the support device 1 6, but the other take down roller 17 is placed on the one end of a lever 27, the other end of which is biased by a spring 28 in such a way that the two take down rollers 1 7 and 17' press against each other at a certain force. This compression can be relieved by a cam 29 on the control drum 11, which cam contacts a cam follow roller 30 at the right moment, which roller is connected to the spring-biased end of the lever 27 for instance via a Bowden cable 31. With said provision the operation of the take down rollers 1 7 and 1 7' can be stopped temporarily.

According to fig 2 the take down device 25 consists of a ram 32 which is placed on a ram bar 33, so that it may perform a reciprocating stroke for instance pneumatically, and the ram 32 should as much as possible hit exactly the sock portion with the weak separation yarns. The ram 32 reciprocates within a framing 34 which is secured to the feed pipe 24 and the exit pipe 26. The particularity of said take down device 25 is, that only in the exit pipe one flap 35 is provided which clamps the article in the pipe 26 just before the stroke of the ram 32. The drive of the flap 35 may take place pneumatically via a line 36 which is also connected to the switch means for the ram 32.

With the described device socks can be knitted efficiently and reliably, while using only two so called solvron yarns of 45/2 den., which means az considerable improvement with respect to the state of the art.

Claims

1. A method for knitting workpieces with a double cylinder circular knitting machine, which is provided with a device to draw off individual workpieces from a coherently knitted strand of workpieces, which are interconnected by separation stitches made with a weak separation yarn, said knitting machine consisting substantially of a needle cylinder and take-down rollers, placed thereunder, which are controlled by a control chain and a control drum, the device to draw off the individual workpieces which is placed thereunder being equipped with a ram and with means to hold the articles during the stroke of the ram, characterized in that the take down rollers are adapted to be moved away from each other by the control drum during knitting the separation yarn so that the take down force is reduced considerably, and that the means to hold the articles during the stroke of the ram consist of a flap which is placed behind the ram in the direction of movement of the articles.

2. A machine for the application of the method according to claim 1, characterized in that one of the take down rollers is mounted on a springbiased lever and is adapted to be moved against the force of a spring by means of a cam on the control drum.

3. A method for knitting workpieces substantially as hereinbefore described with reference to the accompanying drawings.

4. A machine for knitting workpieces substantially as hereinbefore described with reference to the accompanying drawings.

New claims or amendments to claims filed on 18Sept.'81.

Superseded claims 1.

New or amended claims

1. A method for knitting workpieces with a double cylinder circular knitting machine, which is provided with a device to draw off individual workpieces from a coherently knitted strand of workpieces, which are interconnected by separation stitches made with a weak separation yarn, said knitting machine comprising a needle cylinder and take-down rollers, placed thereunder, which are controlled by a control chain and a control drum, the device to draw off the individual workpieces which is placed thereunder being equipped with a ram and with means to hold the articles during the stroke of the ram, characterized in that the take down rollers are adapted to be moved away from each other by the control drum during knitting the separation yarn so that the take down force is reduced considerably, and that the means to hold the articles during the stroke of the ram consist of a clamp which is placed beyond the ram in the direction of movement of the articles.