GB2172306A

GB2172306A - A knitting machine

Info

Publication number: GB2172306A
Application number: GB08602360A
Authority: GB
Inventors: Bernd Biedermann; Siegfried Bottger; Jurgen Hunger; Dieter Rothe
Original assignee: Kombinat Textima VEB
Current assignee: Kombinat Textima VEB
Priority date: 1985-03-12
Filing date: 1986-01-31
Publication date: 1986-09-17
Also published as: DE3602903A1; ES8701869A1; ES552929A0; DD235283A1; GB2172306B; GB8602360D0

Abstract

A circular rib knitting machine, comprises needles (1) and sinkers (4) which project between the needles and can be moved transversely to and longitudinally of the needles to enable the distance required for forming a stitch to be covered partly by the needles and partly by the sinkers. For individual needle selection on the basis of a two- or three-way technique, each needle (1) is pivotally connected to a needle driver (17) which can be moved axially and can also pivot, and which is provided with three feet (18; 19; 20), the middle one (18) of which co-operates with a segment (21) of the needle cam arranged between two adjacent knitting systems for levelling the needle drivers, while the two other feet (19; 20) can engage, according to the pivot position with segments (22; 23) for floating, tucking or knitting. The needle driver 17 is pivoted by a swivel sinker 25, under the control of a set of pattern slides (31). <IMAGE>

Description

SPECIFICATION A knitting machine The present invention relates to a knitting machine. A known R/L circular rib knitting machine comprises needles which can be moved in their longitudinal direction in the grooves of a needle cylinder by a needle cam consisting of various segments for floating, tucking and/ or knitting. Sinkers project between the needles and can be moved transversely to the needles and in the longitudinal needle direction by respective sinker cams, so as to enable the distance required for forming a stitch to be covered partly by the needles and partly by the sinkers.

This known type of machine can achieve high operating speeds, due to the fact that the movement required for forming a stitch is covered partly by the needles guiding the yarn and partly by the sinkers (see for example DE-OS 3311361).

However the disadvantage of this machine lies in the fact that it can only produce campatterned articles.

Individual needle selection by means of a two-or three-way technique, as is usual in conventional right/left circular knitting machines (DE-OS 3 222744) by swinging the needles or the needle drivers away from a single clearing cam per system, cannot be carried out by machines of the type in question, as the clearing cams of the segments each belonging to a respective knitting system of the needle can for floating, tucking and/or knitting are completely different.

An object of the invention is therefore to widen the field of application of machines of the above-mentioned type and enable articles having a wide variety of patterns to be economically produced.

According to the present invention there is provided a knitting machine comprising a plurality of longitudinally displaceable needles, a plurality of sinkers movable relative to the needles whereby the combined movement of the needles and the sinkers performs stitching strokes, a plurality of needle cams for moving the needles, said cams comprising a plurality of segments arranged in groups, each needle having associated therewith a respective set of cam follower means, and control means operable to engage selectively at least one of the cam follower means of a said set thereof with at least one cam segment of a group thereof whereby to control selectively the needle displacements effected by the cams.

In a preferred embodiment of the invention, described in more detail hereinafter each needle is connected via a swivel joint to a needle driver which can be moved axially and radially in relation to the needle cylinder, the needle driver having three cam follower surfaces in the form of feet, the middle one of which is disposed on the driver approximately at the level of the swivel joint and designed to cooperate with an additional segment of the needle cam which is arranged between two adjacent knitting systems for collecting the needle drivers and is provided with a lead-in cone for the needle driver feet, while the other two feet can engage, according to the radial swivel position of the needle driver, with a respective segment, provided for each knitting system, of the needle cam for floating or tucking or knitting.The swivel position of the driver can be adjusted by a respective appropriate pattern device, which is arranged in the area of the needle cam segments, provided between the knitting systems.

Conveniently, the control means is embodied as a swivel sinker which can only be swivelled radially about its lower end. A plurality of such swivel sinkers are associated with the needle drivers. The upper end of the swivel sinker is provided with a fork for accommodating the lower end of an associated needle driver so that it can move freely therein. The pattern device can consist of a stack of pattern slides which can be associated with selection feet on the swivel sinkers.

Two needle cam segments are preferably arranged one above the other for each knitting system; a lower one with a raceway extending radially outwards for knitting and a clearing cam extending radially inwards for tucking, and an upper one with a raceway extending radially outwards for backing and a radially internally disposed covering cam for tucking, the pivotable sinker being displaceable into two of three radial positions by the pattern slide which can be associated with its selection foot.

According to a further preferred feature of the invention, all the pattern slides of one stack are penetrated by a bar, can be removed as a unit with the bar from a housing rigidly connected to the machine and are provided at both front ends with respective pattern cams, one of which can optionally be associated with the selection feet of the swivel sinkers by rotating the slides outside the housing through 1800 about the bar.

According to another preferred feature of the invention, the slides of one stack can be fixed by a pin, which can be inserted in different boreholes in the slides, either in a radially inner position, which influences the selection feet of the swivel sinkers, or in a radially outer, inactive position, and locked in the housing by means of at least one clamping device acting on their external contours.

The invention will now be explained in detail in the following with reference to an embodiment. In the accompanying drawings: Figure 1 is a partial cross section through the needle cylinder of a circular knitting machine according to the invention; Figure 2 is a partial view of the needle and sinker cam of this machine; Figure 3 is a detailed view of the pattern device of the circular knitting machine according to the invention; Figure 4 is a section IV-IV through Fig. 3; Figure 5 is a stack of pattern slides removed from its housing and Figure 6 is a section VI-VI through Fig. 5.

The latch needles 1 of the circular knitting machine are disposed so as to be longitudinally displaceable in grooves 2 of a needle cylinder 3. A sinker 4 is arranged between two respective latch needles 1, which extends over the edge of a needle cylinder 5 and is provided with a loop-forming edge 6 and a foot 7, which engages in a sinker cam 8.

Each sinker 4 is mounted on a lever 9, which can be swivelled about its pivot 12 by two radially acting cams 10, 11. The sinker cam 8, consisting of like segments 13 belonging to a respective knitting system, is mounted on a bearing ring 14 rigid with the machine, each segment 13 being secured to a support 15.

Each latch needle 1 is connected via a swivel joint 16 to a needle driver 17 which can be moved axially and radially with respect to the needle cylinder 3. Each needle driver 17 is provided with three feet 18; 19; 20 arranged one above the other and designed to co-operate with different segments 21; 22; 23 of the needle cam. The lower end of each needle drive 17 is accommodated by the fork 24 of a swivel sinker 25 which can only be swivelled radially about its lower end and which is mounted on a pivot 27 riveted to arm 26.

Each sinker 25 is provided with an extension 29, which can be moved by a radially acting cam 28, and a selection foot 30. In order to actuate the selection feet 30 of the swivel sinkers 25, a stack of pattern slides 31 is provided for each system and is arranged in a housing 32 rigidly mounted on bearing ring 33 (see Figs. 1 and 2). Each pattern slide 31 is provided at its front ends with a respective pattern cam 34; 35. The pattern slides 31 of one stack, i.e. one knitting system, are all penetrated by a bar 36 and a pin 37. For this purpose each pattern slide 31 is provided with an elongated slot 38 and four boreholes 39; 40; 41; 42. The ends of the bar 36 are rigidly connected to two plates 43; 44 holding the stack together, while the pin is only loosely inserted in one of the boreholes 39; 40; 41; 42.

After lifting the spring-loaded clamping bolt 45, which acts on the upper holding plate 42, and removing a strip 47, secured by a clamping screw 46, it is possible to remove the pattern slides 31 of one stack as a unit from the housing 32. Once the pin 37 has been drawn out, the pattern slides 31 can rotate freely about the bar 36. It is thereby possible, by swivelling the relevant pattern slides 31 through 1800 about the bar 36, to bring either of the two pattern cams 34 or 35 into the radially inner position, in which they are directly opposite the selection feet 30 of the sinkers 25.Following a corresponding displacement of the pattern slides 31 by means of a suitable tool, for example a master cam or the like, and the subsequent insertion of the pin 37 in one of the boreholes 39; 40; 41 or 42 and of the slide stack in the housing 32, each pattern slide 31 is fixed, according to the pattern, in a radially internal position, which influences the selection feet 30 of the sinkers 25, or a radially outer inactive position. The entire stack of pattern slides is locked in the vertical position by the springloaded clampin bolt 45 and in the radial position by the strip 47 engaging in recesses 48; 49 in the pattern slides 31 and held by the clamping screw 46. However the strip 47 only acts on the inclined surfaces 49a of the recesses 49 of those pattern slides which are in their inactive position (see figs. 3 and 6).

The method of operation of the circular knitting machine according to the invention is briefly described in the following: Before entering a knitting system (see arrow A in Fig. 2), the swivel sinkers 25 are brought into their radially outermost position, as shown in Fig. 1, by the cam 28 which acts radially on the extension 29. At the same time the feet 18 of the needle drivers 17 move into the cone of the segment 21 of the needle cam, thus adjusting the needle drivers 17 to an approxaimtely uniform level.

According to the situation of the pattern slides 31, the swivel sinkers 25 are then either moved radially inwards or remain in the position shown in Fig. 1. If the pattern slides 31 are in their inactive, radially outer position (see, for example, the fourth slide from the top and the third and fourth slides from the bottom in Fig. 3), the swivel sinkers 25 remain in their radial position as shown in Fig. 1 and, at the point when the feet 18 of the needle drivers 17 leave the segment 21 of the needle cam, the needle drivers 17 are expelled by means of their feet 20, which move into a channel 23a extending radially outwards in the segment 23 of the needle cam, such that their latch needles 1 are moved into the latch clearing position. However if the pattern slide 31 is in its radially inner, active position, such that the pattern cam 34 comes into contact with the selection foot 30 of the corresponding swivel sinker 25 (in Fig. 3, for example, the third slide from the top and the fifth, sixth and seventh slides from the bottom), the swivel sinker 25 is swivelled inwards from the position as shown in Fig. 1 into a central position (not shown). The relevant needle driver 17, the lower end of which is accommodated in the fork 24 of the swivel sinker 25, is thereby swivelled from the position shown in Fig. 1 through a certain distance about the pivot 16 in a clockwise direction.As a result, at the point when the feet 18 of the needle drivers 17 leave the segment 21 of the needle cam, the needle drivers 17 are moved further by means of their feet 19; 20 from the segments 22 and 23, in fact from the tucking-clearing cam 23b (foot 20) extending radially inwards in the segment 23 and the clearing cam 22b-also extending radially inwards-in the segment 22 for the tucking position of the relevant needles 1. However if the pattern cam 35 acts on the selection foot 30 of the corresponding swivel sinker (for example, in Fig. 3 the two top and the two lower slides 31), the swivel sinker 25 is swivelled from the position shown in Fig. 1 into its radially innermost position (not shown).Accordingly, the relevant needle driver 17 is swivelled from the position shown in Fig. 1 about the pivot 16 in a clockwise direction until, at the point when the foot 18 leaves the segment 21 of the needle cam, only the foot 19 of the needle driver 17 is moved further from the segment 22 of the needle cam. The foot 19 then moves into the raceway 22c, which extends radially outwards in the segment 22 and which causes the relevant latch needles 1 to carry out a floating movement; whereas the foot 20 of the needle driver 17 is moved out of the needle cam.Shortly before the feet 19 or 20 of the needle drivers 17 pass through the segments 22 or 23 of the needle cam in the illustrated manner, the swivel sinkers 25 are again forced into the initial position shown in Fig. 2 by the radially acting needle cam 28; while immediately afterwards the needle drivers 17 are again brought to a uniform level by the segment 21 (arranged on the left in Fig. 2), of the needle cam, placed in front of the next knitting system, so that the initial position shown in Fig. 1 is reached again and the swivel sinkers 25 and thus the needle drivers 17 can be reselected by the pattern slides 31 of the next knitting system in order to raise the relevant latch needles 1 for either floating, tucking or knitting.

In each system the movement of the sinkers 4 in the needle raising direction, and in the transverse direction thereto, remains the same irrespective of which latch needles 1 are raised in accordance with the pattern; in fact, after the loop is cleared, the sinkers 4 at each clearing point are moved against the drawingoff movement of the associated needles 1 (by the respective segment 13 of the sinker cam) and outwards transverse to the latter (by the cam 11, which acts on the lever 9) and, after the loop has been cast off, against the needle raising direction (again by the segment 13) and inwards transverse to the latter (by the cam 10, which also acts on the lever 9) in a manner known per se. (See Figs. 1 and 2).

It is obvious that, instead of the described selection between floating, tucking and knitting, the circular knitting machine according to the invention-in a modified form can also be used for selection on the basis of a 2-way technique. In this case the segments 22; 20 of the needle cam need only have one raceway and the swivel sinkers 25 need only be pivotable by the pattern slides 31 into two radial positions.

Claims

1. A knitting machine comprising a plurality of longitudinally displaceable needles, a plurality of sinkers movable relative to the needles whereby the combined movement of the needles and the sinkers performs stitching strokes, a plurality of needle cams for moving the needles, said cams comprising a plurality of segments arranged in groups, each needle having associated therewith a respective set of cam follower means, and control means operable to engage selectively at least one of the cam follower means of a said set thereof with at least one cam segment of a group thereof whereby to control selectively the needle displacements effected by the cams.

2. A knitting machine according to claim 1 wherein each said needle cam follower means comprises a needle driver pivotally attached to a respective said needle, a plurality of cam follower surfaces on the needle driver, and said control means comprises means for selectively pivoting the needle driver to engage said surfaces selectively with the cam segments.

3. A knitting machine according to claim 1 or 2 wherein said needles and said needle cam follower means are mounted on a needle cylinder for rotation relative to the needle cams.

4. A knitting machine according to claim 3 wherein said control means includes a swivel sinker pivotally mounted on the needle cylinder, and a plurality of pattern slide means each associated with a respective said needle cam for selectively pivotally camming the swivel sinker upon rotation of the needle cylinder.

5. A knitting machine according to claim 4 wherein said pattern slide means comprises an arrangement of overlying slide plates projecting radially inwardly of said needle cylinder by a selectable extent.

6. A knitting machine according to claim 3 or 4 including a radially extending cam for positioning the swivel sinker in a predetermined position prior to being influenced by said pattern slide means.

7. A multisytem circular knitting machine comprising needles which can be moved in their longitudinal direction in grooves of a needle cylinder by a needle cam consisting of various needle cam segments, belonging to a respective knitting system, for floating, tucking and/or knitting, and sinkers which project between the needles and can be moved transversely to the needles and in the longitudinal needle direction by a sinker cam formed from like segments belonging to a respective knitting system so as to enable the distance required for forming a stitch to be covered partly by the needles guiding the yarn and partly by the sinkers, characterised in that each needle is connected via a swivel joint to a needle driver which can be moved axially and radially in relation to the needle cylinder, the needle driver having three feet, the middle foot of which is disposed on the driver approximately at the level of the swivel joint and designed to co-operate with an additional segment of the needle cam which is arranged between two adjacent knitting systems for collecting the needle drivers and is provided with a lead-in cone for the needle driver feet while the other two feet can engage, according to the radial swivel position of the needle driver, with a needle cam respective segment provided for each knitting system for floating, tucking or knitting, and in that the swivel position of the driver can be adjusted by a respective appropriate pattern device which is arranged in the area of the needle cam segments provided between the knitting systems.

8. Circular knitting machine according to claim 6 characterised in that a sinker which can only be swivelled radially about its lower end and is provided with a selection foot, is associated with each needle driver, the upper end of which sinker is provided with a fork for accommodating the lower end of the needle driver so that it can move freely therein, the pattern device consisting of a stack of pattern slides which can be associated with the selection feet, arranged in an offset manner, of the sinkers.

9. Circular knitting machine according to claim 8 characterised in that two segments of the needle cam are arranged one above the other for each knitting system; a lower one with a raceway extending radially outwards for knitting and a expulsion cam extending radially inwards for tucking, and an upper one with a raceway extending radially outwards for floating and a radially internally disposed covering cam for tucking, the pivotable sinker being displaceable into two or three radial positions by the pattern slide which can be associated with its selection foot.

10. Circular knitting machine according to claim 9 characterised in that ail the pattern slides of one stack are penetrated by a bar, can be removed as a unit with the bar from a housing rigidly connected to the machine and are provided at both ends with respective pattern cams one of which can optionally be associated with the selection feet of the swivel sinker by rotating the slides outside the housing through 1800 about the bar.

11. Circular knitting machine according to claim 10, characterised in that the slides of one stack can be fixed by a pin which can be inserted in different boreholes in the slides either in a radially inner position, which influences the selection feet of the swivel sinkers or in a radially outer, inactive position, and locked in the housing by means of at least one clamping device acting on their external contours.

12. A circular knitting machine susbstantially as hereinbefore described with reference to the accompanying drawings.