GB2264307A

GB2264307A - Cam system for double-cylinder knitting machine

Info

Publication number: GB2264307A
Application number: GB9303181A
Authority: GB
Inventors: Milan Fucik
Original assignee: Uniplet AS
Current assignee: Uniplet AS
Priority date: 1992-02-21
Filing date: 1993-02-17
Publication date: 1993-08-25
Anticipated expiration: 2013-02-17
Also published as: IT1263614B; FR2687694B1; DE4304947A1; GB9303181D0; CZ50992A3; JPH06287841A; ITMI930326A1; ITMI930326A0; GB2264307B; FR2687694A1

Description

2264307 CAM SYSTEM The invention relates to a cam system of a

double-cylinder circular knitting machine for production of hosiery and similar goods to control double-head latch needles that can be transferred between needle cylinders and are controlled by needle jacks that have mounted on them two guiding butts alternately engageable with cam paths to guide needle jacks in knitting or non-knitting positions.

Double-cylinder circular knitting machines producing hosiery goods that have needle jacks for needles with two butts guiding needles in knitting feeds and for transferring needles between needle cylinders are known. The stitch forming movement of needles is controlled only by one group of butts and this in all knitting feeds, while the second group of butts is used only for auxiliary purposes in transfers between individual cams. The machine is therefore equipped with movable cams so that paths of the needle jacks or of needles are relatively complex. To open the latches of needles, the machine is further equipped with guiding cams of latches in areas where it is not possible to hold opened latches by the opposite empty needle jacks either due to the design of the cam system or the movement of needles in knitting considering the stitch formation. The lower needle cylinder uses for the opening of the upper needles the heel path of the needles. There is no such path in the upper needle cylinder. Therefore, the lower needles have to be opened and the latches held by the guiding cams of the latches.

It is an object of the invention to design a machine that would avoid said fixed guiding cams for latches and also the moving cams, which is substantially fulfilled in that the cam system includes in both needle cylinders paths for guiding empty needle jacks at heights 5071GB - 2 where their tips open latches of the opposite needles, namely at heights that correspond to one group of,guiding butts and/or guiding butts of the mentioned swinging jacks.

It is an advantage of the invention that guiding cams of latches and moving cams are avoided, so that it is possible to use cam rings of gradual shape which diminishes the number of errors caused by breaking of the latches especially during the opening of the so-called border needles by fixed guiding cams of latches.

A preferred embodiment of the equipment according to the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings showing the cam system of the upper and lower needle cylinder.

A known double-cylinder circular knitting machine is provided with a lower needle cylinder 1 and an upper needle cylinder 2 both having in their grooves needle jacks 3 of double-head needles 4 transferable between the needle cylinders 1 and 2. Every needle jack 3 has swingably mounted in a joint a selecting jack 5 with two guiding paths either in the upper 2 or in the lower needle cylinder 1.

The cam system of the lower needle cylinder 1 is formed by the following means, namely a shaped cam ring 7 and a shaped cam ring 8. At the height of guiding butts 51 a cam path 9 is formed in the shaped cam ring 7 in the direction of arrow S from the point B to guide empty needle jacks 3 at a height where their tips open the upper needles 4. Between the points- A and B of the cam path 9 the upper needles 4 are inserted in the lower needle jacks 3. Further a knitting cam path 10 is formed in the shaped cam ring 7 at the height of the guiding butts 51. It is engaged by density cams 11 and 12 of the first and second knitting feed for rotational direction S 5071GB - 3 of knitting. The knitting cam path 10 enters the cam path 9 at point P, the latter being terminated by.. chamfering 91.

A cam path 13 is formed at the height of the lower guiding butts 52 between the shaped cam rings 7 and 8 to guide them or to guide the lower needles 4 at the heel height and also at the height where the tips of the empty lower needle jacks 3 open the upper needles 4. is further provided a knitting cam path 14 for the knitting of plain stitches in the heel during reverse knitting. This cam path 14 is engaged by a density cam 15. The shaped cam ring 8 contains further a Jacquared knitting path 16.

Pushers 17 are used to control pattern butts 51 of the lower selecting jacks 5, controlled by the selecting or pattern making device of the machine using electromagnets.

The cam system of the upper needle cylinder 2 is formed by shaped cam rings 18 and 19 and by a straight cam ring 20. A knitting cam path 23 is formed in the shaped cam ring 18 at the height of the lower guiding butts 51 of the upper selecting jacks 5. Said path 23 is intercepted by density cams 24 and 25 of the first and second knitting feed and is connected with a cam path 26 serving for guiding the needles 4 in transferring between needle cylinders 1 and 2. A cam path 27 is formed between the shaped cam ring 19 and straight cam ring 20 at the height of the upper guiding butts 52 of the upper selecting jacks 5 to guide empty upper needle jacks 3. A firm pusher 28 is formed in the cam path '27 that corresponds to the starting point of the horizontal section of the cam path 23. A firm pusher 29 is further formed in the cam path 13. The cam path 26 is terminated by chamfering 2601 to push out guiding butts 51.

To transfer needles 4 pushers 30 and 31 are 5071GB 4 - present that push guiding butts 52 of the upper or lower selecting jacks 5. At these heights the needle cylinders 1 and 2 are provided with recesses so that the pushers 30 and 31 can push to a greater depth than the depth where the cam paths guide the guiding butts 52.

The operation of the equipment used to open latches of the upper and lower needles 4 described above is as follows:

During rotation of the needle cylinders 1 and 2 in the direction S, the basic selection of needles 4 into the knitting feeds of both needle cylinders is done by the pushers 17. All lower needle jacks 3 with needles 4 come to the pushers 17 because at the point B the lowering upper needles 4 enter in a known way the lower empty needle jacks 3. The pushers 17 separate the guiding butts 51 and 52 into pushed-in and pushed-out ones. The pushed-out guiding butts 52 move through the cam path 13 up to the firm pusher 29 which pushes them in, whereby the appropriate upper guiding butts 51 fit in the cam path 10, so that the corresponding needles 4 knit in the lower needle cylinder 1 in both knitting feeds. The needles 4 are transferred by a known method into the lower needle cylinder 1 so that the pusher 30 pushes down the upper guiding butt 52 and opens the needle jacks 3. The upper needle jack 3 is then guided by the lower guiding butt 51 through the cam path 26 upwards and the lower needle jack 3 is guided by the upper guiding butt 51 in the path 10 horizontally. The needle 4 is transferred by this reciprocal movement of the needle jacks 3 into the lower needle cylinder 1. Chamfering 260f then pushes down the lower guiding butt 51 of the upper needle jack 5, whereby the upper guiding butt 52 is pushed out, so that the empty needle jacks 3 are guided in the path 27 at a height where their tips open or hold lower needles 4 open up to the point C where the lower needles 4 begin to sink but have 5071GB already been threaded. At the point D the tip of the upper needle jack 3 comes into contact with the 1Qwer needle 4 up to the point E where the same takes place as at the point C. At the point F the upper needle jack 3 and the lower needle 4 come again into contact. At the point of the pusher 28 the upper empty needle jack 3 is of course already guided by the guiding butt 51 in the cam path 23 because the pusher 28 has pushed in the guiding butt 52 and pushed out the guiding butt 51.

The upper guiding butts 51 of the lower selecting jacks 5 pushed out by pushers 17 are lifted by the cam path 9 from the point X to the point A.

As the needles 4 are in the upper needle jacks 3, the lower needle jacks 3 push out the upper needle jacks 3 and therefore at the same time also the lower guiding butts 51 of the upper selecting jacks 5 through the path 23 up to the point A'. The lower needle jacks 3 are now opened by the pusher 31 and the upper needle jacks 3 with fit-in needles 4 by means of the cam path 23 take over the needles 4 for knitting in the upper needle cylinder 2.

The empty lower needle jacks 3 are guided by means of the guiding butts 51 through the cam path 9 up to the chamfering 9f which pushes out the guiding butts 52 into the cam path 13 whereby their tips hold the latches of the upper needles 4 open up to the point C' when the upper needles 4 begin to sink with the thread already in them. Then again at the point D they open the upper needles 4 and keep them open to the point E when the upper needles 4 begin to sink again with the thread already in them. At the point F the tips of the lower empty needle jack 3 contact again the upper needles 4 and they are opened. The pushers 17 push in the lower guiding butts 52 belonging to the empty needle jacks 3, whereby the upper guiding butts 51 are pushed out into the cam path 9.

5071GB It is possible within the scope of this invention to situate the cam paths 23 and 10 in the field of activity of the other guiding butts, i.e. the guiding butts 52. The cam paths 27, 13 and 9 guiding empty needle jacks 3 can then be at the height of the second group of the guiding butts. Also, the lower needle cylinder can be without the cam path 9. As the guiding butts 51 and 52 are always engaged with the cam paths there may exist knitting and non-knitting paths, i.e. paths for empty needle jacks combined at various heights and various sections of the needle cylinder arches.

A 5071GB

Claims

1. Cam system of a double-cylinder circulaip knitting machine for the production of hosiery and similar goods for controlling double-head latch needles transferable between needle cylinders and controlled by needle jacks with swingable selecting jacks mounted on them that have two guiding butts alternately selectable for engagement with cam paths for guiding needle jacks in knitting or non-knitting positions wherein the cam system includes in both needle cylinders paths for guiding empty needle jacks at heights where their tips open latches of opposite needles, namely at heights corresponding to one group of the guiding butts and/or the other group of the guiding butts of said swingable selecting jacks.

2. Cam system according to Claim 1, wherein a path for guiding empty needle jacks and a knitting path for guiding needle jacks with needles are in the needle cylinder where cams for reverse knitting are at another height than a cam path for reverse knitting.

3. Cam system according to Claim 1 or Claim 2, wherein in one said needle cylinder, where only rotation knitting is carried out, a cam path is situated at the height of one group of guiding butts to guide empty needle jacks and at the height of the other group of guiding butts is situated a knitting cam path.

4. Cam system constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.