GB2060716A - Circular knitting machines capable of producing face and reverse stitches - Google Patents

Abstract

A circular knitting machine capable of producing face and reverse stitches (stocking stitch) with a conventional single needle cylinder comprises, in radial channels alternating with those which receive the standard sinkers 10, pairs of cooperating laminar members, the first one of which 12 forms a plate hook orientated in a direction opposite to the conventional sinker hook and is radially slidable, while the second laminar member is an oscillating hook member 14, able to gather the last stitch loop formed on a base section of the first laminar member when the first member moves radially inwardly to raise the loop and allow the hook of the first member to insert itself under the loop after another displacement of same, firstly radially outwardly and then again radially inwardly. The loop is thus moved behind the needle. <IMAGE>

Description

SPECIFICATION Circular knitting machines capable of producing straight and reverse stitches The present invention relates to circular knitting machines capable of producing straight and reverse stitches.

Conventionally knitwear formed with so-called stocking stitches, that is to say with straight and reverse stitches, is produced using knitting machines with two layers of needles or with double needles and a double needle cylinder.

According to the invention there is provided a circular knitting machine for.the production of straight and reverse stitches using a single needle cylinder, said machine comprising a needle cylinder, radial sinkers arranged around the axis of the cylinder, each sinker having a hook, cooperating laminar members arranged between at least some of the adjacent pairs of sinkers, each pair of cooperating members consisting of a first member having a hook orientated in a direction opposite to that of the sinker hook and being radially movable, and a second member which is an oscillating hook member effective to gather the last stitch loop formed on the first member when said first member moves radially outwards so as to raise said loop and allow the hook of the first member to be inserted under said loop after subsequent inwards and outwards radial movement whereby the loop is thus moved behind the needle.

The second member may comprise an edge for supporting the loop to be raised and with a projection in the form of a hook extending upwards from said edge to retain the loop, the second member being movable from a position under the base profile or loop-supporting edge of the first member to a position raised above said hook of the first member.

In a practical embodiment, the machine comprises a first control track for moving the first member, firstly radially inwardly and then radially outwardly, and a second control track for causing pivoting of the second member to effect the raising of the second member before and during the radially outwards displacement of the first member, the lowering of said second member at the end of the radially outwards displacement of the first member, and a partial new lifting of said second member before the first member moves back to bring about the projection of the hook and retain the next loop that is formed.

The machine may be a conventional machine with a single needle cylinder, in which some of the sinkers are replaced by the pairs of laminar members, and in which special cam profiles are provided for the control of the sinkers.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a fragmentary vertical section of a circular knitting machine in accordance with the invention, and showing part of the needle cylinder, with sinkers and means for controlling the sinkers; Figures 2 and 3 are sections taken on lines lI-Il and Ill-Ill of Figure 1; Figure 4 is a view along line IV--IV of Figure 1; Figure 5 is a view, in a radially outwards direction of the sinkers and of the cooperating needles in a fabric formation area; Figures 5A and 5B are sections taken on lines A-A and B-B of Figure 5;; Figure 6 is a view along line Vl-Vl of Figure 5 and illustrating a fabric formation area; Figures 7 to 11 show in an axial view, and Figures 7A to 11 A show in perspective, the relative positions of the members for the formation of the straight and reverse stitches in various stages of the formation cycle of the fabric; Figures 12, 13 and 14 show a pair of cooperating laminar members in the same radial channel, in three different relative positions; and Figure 1 5 shows in isolation the laminar members and the sinker.

As illustrated in the accompanying drawing, the circular knitting machine is a single cylinder machine (rather than a double cylinder machine) which is equipped with means for knitting straight and reverse stitches (stocking stitches). The machine has a cylinder 1 with needles 3 of normal type for single-cylinder machines. 5 denotes an outer annular support with radial channel adapted to contain conventional sinkers alternated with pairs of laminar members to be described hereinunder, the alternating arrangement of the sinkers and the laminar members being dependent on the required distribution of straight and reverse stitches along the rows of stitches of the fabric being made. Generally, 7 denotes the sinker housing which is fixed or movable in conventional manner to control the sinkers and the laminar members of the pairs of laminar members.

In the example shown, which provides for knitting straight and reverse stitches on a 1:1 basis, in the radial channels of the support 5, there are received in succession a conventional sinker 10 and two laminar members 12, 14 for the formation, respectively, of straight stitches and reverse stitches with the same needles 3. The sinkers 10 (see Figure 15) are of laminar form and have a loop-supporting edge 1 OA corresponding to the plane of fabric formation and a sinker hook 1 OB which is orientated radially towards the axis of the needle cylinder. The sinker 10 also has a pair of edges 1 OC (Figure 1 5) for effecting radially inwards and outwards movement, in conjunction with a control profile to be described hereinafter.

One of the two laminar members denoted by 12 has a loop supporting-edge 1 2A similar to the edge 1 OA and a hook 1 2B turned in the direction opposite to that of the hook 1 OB of sinker 10. The first laminar member 12 has a pair of edges 1 2C similar to those denoted by 1 OC for effecting radial movement. The second laminar member 14 is a hook member, pivoting about a point 1 4A towards which two slanting lower edges of the member 14 converge. The member 14 has an edge 1 4B for supporting the loop, and a hook projection 1 4C. At the opposite end to the projection 1 4C the second laminar member 14 has a heel 1 4E to receive a thrust along line fE of Figure 1 5 and therefore to effect a lifting movement of the profile 1 4B, 1 4C.A part of the upper edge 1 4G is used to receive a thrust along line fG and therefore to effect a lowering of the profile 1 4B, 1 4C. These raising and lowering movements occur always about point 1 4A which rests at the bottom of the radial channel of the support 5, in which the pair of members 12, 14 is received. In Figures 12 to 14 three relative positions are shown, which may be reached by the laminar members 12, 14 as a result of an angular movement of the member 14 and a radial siiding of the member 12.

In the housing 7, facing the or each feed, provision is made for a control profile 1 8 which (see in particular Figure 4) has, in axial view, a portion 1 8A for effecting radially outwards movement of the sinkers 1 0 and of the elements 12, a portion 1 SB for maintaining the sinkers 10 and the members 12 in their radially outer positions, and a subsequent portion 1 SC for effecting radially inwards movement of the sinkers 10 and members 12. The direction of movement of the components 10, 12, 14 relative to the housing 7 is indicated by the arrow fR and corresponds to the direction of rotation of the needle cylinder.In the view of Figure 3 the profile 18 has, parallel with the axis of the needle cylinder, a lifting portion 1 so, a raised portion 1SF, a lowering portion 1 8G and a lowered portion 1 SH (all in the area of portions 2 8A and 1 8B) as well as a short lifting portion 1 8L and a partly raised portion 1 so. Correspondingly to the control profile 18, provision is made on the housing 7 for a second control profile 20 (see also Figure 2) which has a raised portion 20A, a lowering portion 20B and a lowered portion 20C, (corresponding to portion 1 8F), a lifting portion 20E substantially facing the portions 1 8G and 1 so, a raised portion 20F, and a lowering portion 20G to resume the level 20A, portion 20G being immediately after portion 1 8L of profile 18.

The operation is as follows: Figure 7 shows the position substantially corresponding to arrow NII of Figure 6. The stitch M1 is engaged by the hook or projection 1 4C which projects slightly from the edge 1 2A; a thread M2 is taken by the needle performing a downward movement. In a subsequent stage, illustrated by arrow NIII in Figure 6 and in Figure 8, the needles have come down below the sinker plane, the laminar member 14 has raised the stitch M1 above the edge 1 2A and above the hook 1 2B; the hook 1 2B with the member 12 is moved forward in the direction of arrow NIll and wedges inside the loop of stitch Ml. The needle, as it came down, formed the stitch M2. Similarly facing the sinker 10 straight stitches are formed.In a subsequent position, shown by arrow flX of Figure 6 and in Figure 9, the laminar member 14 has come down completely below the edge 1 2A, while the stitch M1 rests on the back of the hook 1 2B. As member 12 continues to move forward in the direction of arrowNlll, in a subsequent position shown in Figure 10 and corresponding substantially to the position of arrow fXI of Figure 6, the stitch M1 is moved behind the vertical path of the needles while the projection 1 4C is brought below the stitch M2, moved forward from the bottom of the recess defined by the hook 1 2. Again in a subsequent position, shown in Figure 11 and approximately by arrow fXI of Figure 6, the laminar member 14 is again made to pivot to protrude with the projection 1 4C above the edge 1 2A and therefore inside the loop of stitch M2.At this point the movement of the laminar member 12 is reversed from the direction shown by arrow NIl to the direction shown by NII in Figure 7, while the needle rises again and the position of Figure 7 is resumed. It follows from this that, while the stitches formed by the needles flanking the normal sinkers 10 produce a straight stitch as shown by MD in Figure 6, stitches MR formed facing the pairs of laminar members 12, 14, are reversed stitches. In the embodiment illustrated, provision is made for a sinker 10 and a pair of plates 12, 14 with 1:1 arrangement, and therefore the stocking fabric i.e. with straight and reverse stitches progresses on a 1:1 basis. However the arrangement may be modified to obtain different arrangements in the succession of straight stitches and reversed stitches.

The control in radial direction of the sinkers 10 and of members 12 is obtained with the edges 1 OC and 1 2C cooperating with the side walls of the control profile 1 8, while the pivoting of the laminar member 14 is obtained using the axial profiles to be seen in Figures 2 and 3 of the control profile 18 and 20.

As particularly described, stocking stitches can be produced with a single needle cylinder, with conventional needles for same, simply by equipping the machine with relatively inexpensive components easily mounted on the machine and removed from it. The machine can also be used for conventional knitting.

Claims (4)

1. A circular knitting machine for the production of straight and reverse stitches using a single needle cylinder, said machine comprising a needle cylinder, radial sinkers arranged around the axis of the cylinder, each sinker having a hook, cooperating laminar members arranged between at least some of the adjacent pairs of sinkers, each pair of cooperating elements consisting of a first member having a hook orientated in a direction opposite to that of the sinker hook and being radially slidable, and a second member which is an oscillating hook member effective to gather the last stitch loop formed on the first member when said first member moves radially outwards so as to raise said loop and allow the hook of the first member to be inserted under said loop after subsequent inwards and outwards radial movement, whereby the loop is thus moved behind the needle.

2. A machine according to claim 1, wherein the second member comprises means defining an edge for supporting the loop to be raised and a projection in the form of a hook extending upwards from said edge to retain the loop, and the first member has means defining a loop supporting edge, said second member being movable from a position under the supporting edge of the first member to a position raised above the hook of the first member.

3. A machine according to claim 1 or claim 2, further comprising means defining a first control profile for moving the first member firstly radially inwardly and then radially outwardly, and means defining a second control profile for pivoting the second member to effect the raising of the second member before and during the radially outwards displacement of the first member, the lowering of said second member at the end of the radially outwards displacement of the first member, and a partial lifting of said second member before said first member moves back to bring about the projection of the hook and retain the next loop that is formed.

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