GB2306513A

GB2306513A - Sinkers for knitting machines

Info

Publication number: GB2306513A
Application number: GB9621564A
Authority: GB
Inventors: Kyung-Mok Lee
Original assignee: KUM YONG MACHINERY CO Ltd
Current assignee: KUM YONG MACHINERY CO Ltd
Priority date: 1995-10-24
Filing date: 1996-10-16
Publication date: 1997-05-07
Also published as: ES2154086B1; JPH09176941A; ES2154086A1; IT1285536B1; TW360726B; KR960014598B1; ITMI962192A1; DE19643433A1; GB9621564D0; JP2917130B2

Description

517GB 1 Improvements in Circular Knitting Machines 2306513 This invention

relates to improvements in knitting machines, and particularly in circular knitting machines.

It was devised particularly to enable more complex patterns to be produced without the use' of highly-skilled operators. The improvements of the present invention relate chiefly to changes in the shape and mode of operation of sinker pins and sinker cams of the knitting machine and to a method of knitting a patterned fabric using such modified sinker pins and sinker cams. Since it is chiefly applicable to circular knitting machines, the invention will be described with reference to such machines, but may be applicable with modifications to other, e.g. flat bed knitting machines.

Conventionally, sinker pins of a circular knitting machine are made of thin metal, usually steel, sheets and are positioned between one needle and another. 7hey are arranged to move radially back and forth relative to the vertically reciprocating latch type knitting needles under the control of a sinker cam so as to assist the needles to carry out knitting by receiving the yam in a throat area, forming loops, and holding down the knitted fabric to prevent it becoming stretched.

A conventionally shaped sinker pin is shown in side elevation in Figure 2 (Prior Art). It will be seen to have a generally linear shape with no butt. Further reference will. be made to the conventional sinker pin below.

In the prior art, only simple patterns can be produced in thin knitted textiles except by use of considerable skill because they must be produced using arrangements of needles and pattern wheels. There is a limited range of pattern options available and the patterns take a long time to produce on the knitted fabric, reducing productivity of the machine. The extra skill required to produce patterned knitted fabric on a circular knitting machine raises both g and employment costs for suitably skilled people and there can be shortages of skilled labour.

17GB 2 If unskilled people attempt to carry out this work, there are risks of damage and danger.

Various objects of the present invention include: to provide a circular knitting machine; components for a circular knitting machine; a method of operating a circular knitting machine; and a method of knitting a patterned fabric; which allow relatively unskilled workers who do not constitute a specialist workfarce to address the task of operating circular knitting machines within a short time and to allow a greater variety of patterns to be produced.

According to a first aspect, the invention provides a sinker pin for a knitting machine having an elongate forward portion which is of per se known shape having a generally linear lower edge, and a back portion extending generally at right angles to said lower edge of said elongate forward portion and providing a back edge, the back portion having a butt projecting from said back edge generally parallel to said linear lower edge at a predetermined spacing therefrom.

The sinker pin may be shaped as illustrated in any one of Figures 3a to 3d of the accompanying drawings.

A set of sinker pins may be provided, each one of said set having a butt projecting therefrom at a different predetermined spacing.

In a preferred embodiment, a set of sinker pins comprises four sinker pins, the butts being provided at predetermined positions approximately equally spaced along said back edge from an upper to a lower part thereof. The sinker pins of a set may be arranged sequentially in order of their butt positions.

Viewed from another aspect, the invention provides a knitting machine having needles, a plurality of sets of sinker pins, an actuator adapted to select one or more of the sinker pins of each set of sinker pins and move each selected sinker pin to an operative condition, a sinker cam adapted to contact and drive the sinker pin in an operative condition, and control means for the actuator.

517GB 3 The actuator may have a plurality of actuation fingers, each adapted to contact a butt of a respective one of said sinker pins of a set in order to select said one sinker pin and move it into said operative condition.

The control means may comprise a computer control, arranged to operate the actuation fmgers in accordance with a predetermined program which may be input into the control means from a chip or disk or other recordal device.

A circular knitting machine embodying the invention may have a sinker cam adapted to contact and drive a sinker pin in an operative position, a sinker cam ring on which a plurality of sinker cams are mounted in sequence, and a dial on which a plurality of sets of sinker pins are assembled in sequence for actuation by actuation fingers of said actuator under control of the control means.

The sinker cam may be shaped as illustrated in Figure 6 of the accompanying drawings.

Viewed from a still further aspect, the invention provides a method of operating a circular knitting machine; and a method of knitting a patterned fabric comprising the steps of taking a circular knitting machine having needles, a plurality of sets of sinker pins, each sinker pin having an elongate forward portion which is of per se known shape having a generally linear lower edge, and a back portion extending generally at right angles to said lower edge of said elongate forward portion and providing a back edge, the back portion having a butt projecting from said back edge generally parallel to said linear lower edge at a predetermined spacing therefrom, each one of said set of sinker pins having a butt projecting therefrom at a different predetermined spacing, an actuator adapted to select one or more of the sinkers of each set of sinker pins and move it to an operative condition, a sinker cam adapted to contact and drive the sinker pin in said operative condition, and control means for the actuator; causing said machine to operate to raise and lower the needles sequentially; operating said control means for the actuator to select predetermined ones of said 17GB 4 sinker pins, whereby said selected sinker pins are moved to an operative condition and contacted and driven by said sinker cam to cooperate with associated needles to knit a pattern.

The method may include the step of providing a plurality of actuation fingers on the actuator, each adapted to contact a butt of a respective one of said sinker pins of a set in order to select said one sinker pin and move it to an operative condition.

The method may include the step of programming a computer control means arranged to operate the actuation fingers in accordance with a predetermined program.

A knitting machine, components for a knitting machine, a method of operating a knitting machine and a method of knitting a patterned fabric, all in accordance with aspects of the invention, will now be described in more detail by way of example only with reference to the accompanying drawings, in Which:- Figures la to le are sequence diagrams showing parts of a circular knitting machine in operation; Figure 2 (Prior Art) illustrates a conventional sinker pin in side elevation;

Figures 3a to 3d are side elevational views of a plurality of sinker pins forming a set, and embodying the present invention; Figures 4a to 4d show the set of sinker pins in exploded perspective; FIggre 5 is a plan view of an actuator; Figure 6 is a plan view of a pair of adjoining sinker cams; Figure 7 is a sectional view through the bed of a knitting machine, showing the operating 517GB parts.

Referring to Figures 1 and 2 of the drawings, a knitting machine, in this example a circular knitting machine, has a large number of needles 13 of latch type, which are arranged in a bed so as to reciprocate up and down under the action of drive cams as the knitting machine rotates. A first drive cam 11 is a raising cam, and a second drive cam 12 is a lowering cam. From the sequence of drawings forming Figure 1, it can be seen that each needle has a butt 9 which is driven by the cams, 11 and 12 on relative rotation to perform a knitting operation in cooperation with an associated sinker pin 2.

The present invention relates to changes made to the sinker pin, compared with the conventional sinker pin 2 shown in Figure 2. This is made of sheet metal, usually steel, and has an elongate form, including a linear lower edge 20. The profile of the upper edge, particularly at the forward portion 34 shown on the left-hand side of Figure 2, is not of relevance to this application. However, the sinker pin used in the present invention differs in shape from the sinker pin 2 of Figure 2 at the back (or right-hand end as illustrated in Figures 3 a to 3 d). The sinker pin of Figure 3 has a back portion 3 5 having a rear edge 10 extended at right angles below the level of the linear lower edge 20.

The novel sinker pins are provided in sets. In the example shown in Figures 3a to 3d each set includes four sinker pins 30, 31, 32, 33, which differ from each other in only one respect. Each sinker pin has a butt on the back edge. The difference between the pins can be seen to be a difference in positioning of this butt.

A first level butt 90 is provided on the sinker pin 30 of Figure 3a, close to the top of the back edge 10. In the sinker pin 31 of Figure 3b, the butt 91 provided is spaced away from the top of the back edge. The next sinker pin 32, shown in Figure 3c has a butt 92 which is positioned lower, and the final sinker pin 33 of the set, shown in Figure 3d has a butt 93 at the bottom of the back edge.

In use, the sinker pins 30, 31, 32, 33, of the set shown in Figures 3a to 3d are arranged 517GB 6 together side by side as illustrated in the exploded perspective view of Figure 4.

Referring now to Figure 7, the knitting machine shown has a cylinder 6 which carries the reciprocating needles 13. Between the needles, sinker pins 30, 3 1, etc., are provided in sets, arranged in the order or sequence shown in Figure 4. Some of the sinker pins are selected at each pass of the machine, while some are not selected, according to the program used for controlling an actuator 4.

Referring back to Figure 1, (a) while the needle 13 is rising, the sinker pin 2 supports the old loop at the forward position, (b,c) once the needle 13 receives yam, the sinker pin 2 withdraws, (d) at the release of the loop, the sinker pin 2 is at the rearward position and prevents excessive tension in the old loop, (e) when the needle begins rising to form the next loop, the sinker pin 2 moves forward to aid the winding-in action while pushing the needle to prevent the needle from piercing the just-completed new loop A conventional circular knitting machine for knitting thin fabrics such as for underwear employs a sinker pin 2 without a butt such as that shown in Figure 2. Such a conventional machine can make simple patterns using a pattern wheel and the arrangement of needles. However, the patterning using a sinker pin without a butt has low productivity due to the limited patterning range and the long fashioning time for knitted fabrics. In addition, novice workers can make only simple patterns due to the high skill needed for fashioning with such a circular knitting machine. The cost also increases because of employing highly paid skilled workers or training workers for a long period of time to operated a circular knitting machine. This problem is increased because workers nowadays frequently change jobs. Another problem is the substantially higher chance of accidents if a novice worker operates the machine.

The present invention has been devised to overcome problems such as those mentioned above 517GB 7 and aims to enable novice workers to operate the circular knitting machine with a short period of training time and to make patterns of greater size and complexity.

With this end in view, sinker pins are used in sets of typically four sinker pins having butts of four different levels or positions formed on rear surfaces of the sinker pins.

Further, the sinker cam track for moving the sinker pins is formed in the shape illustrated in Figure 6 of the drawings, to move the sinker pins to fashion complicated patterns.

An additional feature is the provision of an multi-level electronic or mechanical selector device, mounted for example on a top plate attached to an upper portion of a circular knitting machine to control the type of sinker pin described above for fashioning patterns.

Figure 3 shows the sinker pin of the present invention in front elevation: 3a is a view of a first-level sinker pin 30; 3b, 3c and 3d are views of second, third and fourth-level sinker pins 31, 32 and 33 respectively. These have an elongate forward portion 34 like that of the conventional sinker pin 2 of Figure 2 (prior art) but they each have a back portion 35 providing a rear edge 10 extending generally at right angles to the lower edge 20 of the elongate forward portion 34. Butts project from the back edge 10 of the back portion 35 at different levels or positions relative to the level of for example the lower edge 20. A first level butt 90 is provided on the first-level sinker pin of Figure 3a, close to the top of the back edge 10. In the second-level sinker pin of Figure 3b, the butt 91 provided is spaced away from the top of the back edge. The nex third-level sinker pin, shown in Figure 3c has a butt 92 which is positioned lower, and the final, fourth-level sinker pin of the set, shown in Figure 3d has a butt 93 at the bottom of the back edge 10 of the back portion 35.

In use, the sinker pins of the set shown in Figures 3a to 3d are arranged together side by side as illustrated in the exploded perspective view of Figure 4, and they are positioned in this sequence on a dial 8 (Figure 7).

517GB 8 An actuator 4 is provided in which actuator fingers 5 are provided so as to protrude to the outside. These are movable in response to movement provided by internal members within the actuator casing, controlled by electromagnetic or mechanical motive force. The fingers 5 can move up and down vertically, and this acts to select the sinker pins associated with the fingers.

Using electromagnetic or other means, the actuator fingers 5 provided protruding from part of the actuator 4 select the predetermined ones of the four sinker pins 30, etc., formed with butts 90, etc., in different positions. The actuator can therefore select a sinker pin 30, etc., to be used for patterning since the actuator fingers 5 move with the internal members and the sinker pins are moved by the actuator fingers 5.

The actuator fingers 5 are installed on the actuator which is mounted below a sinker carn ring 7. A fixed predetermined distance is maintained between the butts 90, etc., of the sinker pins 30, etc., installed on the dial 8 as shown in Figure 7, in order to fashion patterns in the knitted fabric.

The actuator 4 electromagnetically or otherwise selects one of the sinker pins, for example the sinker pin 30, out of the four sinker pins 30, 31, 32, 33 of the set, according to the respective position of the butts 90, 91, 92, 93. Subsequently the selected sinker pin 3 0 moves to form a normal loop with a needle risen to a knit position while the rest of the sinker pins 31, 32, 33 which are not selected, remain stationary. Knitting yam of the selected pin corresponding to the normal loop appears at the surface of the knitted fabric, while no loop of yam corresponding to those sinker pins not selected appears on the knitted fabric. Therefore the sections of normal loops and without loops appearing at different places, provide the patterned appearance on the face of the knitted fabric.

Pattern instructions can be stored on computer disks or in memory chips to make the actuator fingers 5 move continuously and repetitively according to the stored pattern to select or deselect the various sinker pins. The resultant patterning of the loops on the surface of the knitted fabric forms a pattern.

517GB 9 The operation of the preferred embodiment of the present invention and its effect will be described below.

When the power is turned on and the apparatus activated, the dial 8 fixedly attached to the cylinder 6 of the apparatus and the sinker pins 3 assembled by insertion in the groove of the dial rotate together with the rotation of the cylinder. Among the plurality of multi-level sinker pins 30, 31, 32, 33, in which butts 90, 91, 92, 93 respectively are integrally formed on the back surfaces, the actuator selects one sinker pin, for example 30, with the vertical movement of the actuator finger 5 protruding from the actuator 4, according to a pattern stored in a disk or chip or otherwise input to the control apparatus of the actuator.

The sinker cam 1 is formed with the shape shown in Figure 6, and a plurality of such sinker cams 1 are linked together to forni a continuous fixed sinker cam track as shown.

71e selected sinker pin 30 moves along the track on the sinker cam 1 to form a loop with the associated needle, whereas the non-selected sinker pins do not form loops at this pass of the machine. The pattern is thus knitted into the thin knitted fabric such as for underwear by the selection of sinker pins.

The abovementioned method makes it possible to produce a fixed pattern or a continuous or repeating pattern indefinitely.

An advantage of the present invention is that unit production costs can be reduced since patterns can be knitted even by unskilled or non- specialist workers.

Other advantages are that diverse and varied patterns can be knitted and that the various types of patterns can be knitted in a short time using the installed sinker pins.

517GB

Claims

1. A sinker pin for a knitting machine having an elongate forward portion which is of per se known shape having a generally linear lower edge, and a back portion extending generally at right angles to said lower edge of said elongate forward portion and providing a back edge, the back portion having a butt projecting from said back edge generally parallel to said linear lower edge at a predetermined spacing therefrom.

2. A set of sinker pins, each according to claim 1, each sinker pin of said set having a butt projecting therefrom at a different such predetermined spacing.

3. A set of sinker pins according to claim 2 and comprising four sinker pins.

4. A set of sinker pins according to claim 2 or claim 3 wherein the butts are provided at predetermined positions approximately equally spaced along said back edge from an upper to a lower part thereof.

5. A set of sinker pins in which the sinker pins are arranged sequentially in order of their butt positions.

6. A knitting machine having needles, a plurality of sets of sinker pins, each set of sinker pins being in accordance with any one of claims 2 to 5, an actuator adapted to select one or more of the sinker pins of each set of sinker pins and move each selected sinker pin to an operative condition, a sinker cam adapted to contact and drive the sinker pin in an operative condition, and control means for the actuator.

7. A knitting machine according to claim 6 wherein the actuator has a plurality of actuation fingers, each adapted to contact a butt of a respective one of said sinker pins of a set in order to select said one sinker pin and move it into said operative condition.

8. A knitting machine according to claim 7 wherein the control means comprise a 517GB 11 computer control, arranged to operate the actuation fingers in accordance with a predetermined program.

9. A circular knitting machine according to any one of claim 6 to 8 and having a sinker cam adapted to contact and drive a sinker pin in an operative position, a sinker cam ring on which a plurality of sinker cams are mounted in sequence, an actuator mounted beneath the sinker cam ring, and a dial on which a plurality of sets of sinker pins are assembled in sequence for actuation by actuation fingers of said actuator under control of the control means.

10. A method of operating a circular knitting machine comprising the steps of. taking a circular knitting machine having needles, a plurality of sets of sinker pins, each sinker pin having an elongate forward portion which is of per se known shape having a generally linear lower edge, and a back portion extending generally at right angles to said lower edge of said elongate forward portion and providing a back edge, the back portion having a butt projecting from said back edge generally parallel to said linear lower edge at a predetermined spacing therefrom, each one of said set of sinker pins having a butt projecting therefrom at a different predetermined spacing, an actuator adapted to select one or more of the sinkers of each set of sinker pins and move it to an operative condition, a sinker cam adapted to contact and drive the sinker pin in an operative condition, and control means for the actuator; causing said machine to operate to raise and lower the needles sequentially; operating said control means for the actuator to select predetermined ones of said sinker pins, whereby said selected sinker pins are moved to an operative condition and contacted and driven by said sinker cam to cooperate with associated needles to knit a pattern.

11. A method of operating a circular knitting machine according to claim 10, the circular knitting machine having a plurality of actuation fingers on the actuator, each adapted to contact a butt of a respective one of said sinker pins of a set, the method including the step of moving one of said actuation fingers in order to select said one sinker pin and move it to 517GB 12 said operative condition.

12. A method of operating a circular knitting machine according to claim 11 and including the step of programming a computer control means arranged to operate the actuation fingers in accordance with a predetermined program.

13. A method of knitting a patterned fabric comprising the steps of taking a circular knitting machine having needles, a plurality of sets of sinker pins, each sinker pin having an elongate forward portion which is of per se known shape having a generally linear lower edge, and a back portion extending generally at right angles to said lower edge of said elongate forward portion and providing a back edge, the back portion having a butt projecting from said back edge generally parallel to said linear lower edge at a predetermined spacing therefrom, each one of said set of sinker pins having a butt projecting therefrom at a different predetermined spacing, an actuator adapted to select one or more of the sinkers of each set of sinker pins and move it to an operative condition, a sinker cam adapted to contact and drive the sinker pin in an operative condition, and control means for the actuator; causing said machine to operate to raise and lower the needles sequentially; operating said control means for the actuator to select predetermined ones of said sinker pins, whereby said selected sinker pins are moved to an operative condition and contacted and driven by said sinker cam to cooperate with associated needles to knit a pattern.

14. A method of knitting a patterned fabric according to claim 13, comprising taking a circular knitting machine having a plurality of actuation fingers on the actuator, each adapted to contact a butt of a respective one of said sinker pins of a set, the method including the step of moving one of said actuation fingers in order to select said one sinker pin and move it to said operative condition.

15. A method of knitting a patterned fabric according to claim 14 and including the step of programming a computer control means arranged to operate the actuation fingers in 17GB 13 accordance with a predetermined program.

16. A sinker pin substantially as hereinbefore described with reference to, and as illustrated in any one of Figures 3a to 3d; or 4a to 4d; of the accompanying drawings.

17. A sinker cam substantially as hereinbefore described with reference to, and as illustrated in Figure 6 of the accompanying drawings.

18. A circular knitting machine substantially as hereinbefore described with reference to, and as illustrated in Figures 3 to 7 of the accompanying drawings.

19. A method of operating a circular knitting machine substantially as hereinbefore described with reference to, and as illustrated in Figures 3 to 7 of the accompanying drawings.