GB2261883A

GB2261883A - Double-cylinder circular knitting machine

Info

Publication number: GB2261883A
Application number: GB9224773A
Authority: GB
Inventors: Milan Fucik
Original assignee: Uniplet AS
Current assignee: Uniplet AS
Priority date: 1991-11-27
Filing date: 1992-11-26
Publication date: 1993-06-02
Anticipated expiration: 2012-11-26
Also published as: GB2261883B; GB9224773D0; CZ280576B6; ITMI922720A0; ITMI922720A1; IT1261296B; CZ359191A3; JPH06128849A

Abstract

A fabric take-down mechanism in a double-cylinder knitting machine comprises within the lower cylinder (1) a fabric withdrawing element (10) provided with a helical surface (101) for engaging the knitwork, the surface (101) cooperating with lower edges of press-off sinkers (8) mounted in the lower portion of a supporting element (7) of the upper needle cylinder (2) or with similarly-located plates, the sinkers or plates resisting twisting of the fabric. The sinkers (8) or plates project by a distance (t) from the supporting element and may be resiliently loaded. Instead of the helical surface (101) being integral with the element (10) it may be formed by a steel strip inserted into the element. <IMAGE>

Description

DOUBLE-CYLINDER CIRCULAR KNITTING MACHINE The invention relates to a double-cylinder circular knitting machine for manufacturing hosiery, the machine comprising a lower and an upper needle cylinder with latch needles, wherein in the lower needle cylinder there is coaxially disposed a lower circular withdrawing element having a helical surface designed for engaging the knitwork.

There is known a double-cylinder circular knitting machine for manufacturing hosiery, provided with a withdrawing device comprising two withdrawing elements, wherein the helical surface of the first element bears on grooves formed in the second withdrawing element; said grooves are orientated towards the centre of the latter.

Such a device is designed for withdrawing the knitwork made on the full number of needles, and for preventing it from being twisted.

A drawback of such a withdrawing device consists in that it is practically impossible, if the needle cylinder is finely indexed, to provide a corresponding number of radial grooves, since, especially in the central region of the second withdrawing element, there is actually no room for them. Apart from this, the working of both said grooves and the helical surface is problematic. Another disadvantage is in that the grooves are rigid and cannot yield if exposed to the knitwork pressure in critical zones thereof.

It is an object of the present invention to eliminate the drawbacks as hereinabove set forth, and to provide an improved double-cylinder circular knitting machine for manufacturing hosiery. The machine comprises a lower and an upper needle cylinder in which, in their longitudinal tricks, latch needles and sinkers for controlling them are mounted. In the lower needle cylinder there is coaxially arranged a lower circular withdrawing element, in the upper portion of which a helical surface designed for engaging the knitwork is provided.

According to the invention, the helical surface of the lower cylinder is disposed to face lower edges of press-off sinkers or of sheets received in the lower portion of supporting elements of the upper needle cylinder. The height of each press-off sinker or sheet is greater than the depth of longitudinal grooves in the supporting elements of the upper needle cylinder, in which the press-off sinkers or the sheets are disposed in such a way that the lower edges of the sinkers or sheets, respectively, overlap the lower front portion of the supporting elements downwards to the helical surface of the lower circular withdrawing element.

In an alternative embodiment, the helical surface of the lower withdrawing element is constituted by a resilient steel sheet which is received in a helical groove provided in a ring drawn over the upper tubular portion of said lower withdrawing element.

The sheets received in the longitudinal grooves in the supporting element of the needle cylinder are spring-loaded.

It is an advantage of the present invention that the press-off sinkers are perfectly worked so that no indexing problems arise and further that said press-off sinkers actually assume the function of the second knitwork withdrawing element so that the necessity of providing an additional special element as well as of mounting it, can be omitted. If the press-off sinkers are moreover combined with sheets, the latter can be mounted in the supporting elements as spring-loaded pieces whereby the pressures produced by knitwork are reduced and the danger of.cutting through the fabric is avoided.

In order that the present invention be better understood and carried into practice, some preferred embodiments thereof will hereinafter be described with reference to the accompanying diagrammatic drawings in which: Figure 1 shows a knitting machine together with the needle cylinders in a partial axial sectional view, and with the fabric withdrawing means in operating position; Figure 2 is a view corresponding to that shown in Figure 1, except that the withdrawing means are outside said operating position; Figure 3 shows a variant where the press-off sinkers are combined with sheets in the upper needle cylinder; Figure 4 is a variant where the helical surface of the lower withdrawing element is constituted by a steel sheet received in a helical groove; Figure 5 shows a detail of securing the steel sheet in Figure 4; and Figure 6 shows an embodiment where the supporting element is made as the upper withdrawing element and carries spring-loaded sheets.

As can be seen in the drawings, a double-cylinder circular knitting machine for manufacturing hosiery comprises a lower needle cylinder 1 and an upper needle cylinder 2. The cylinders are provided with longitudinal tricks receiving latch needles and sinkers for controlling them (not shown). In the lower needle cylinder 1 there is mounted a coaxial lower circular withdrawing element 10 for axial reciprocation but not for rotation. On the upper portion of said element 10 a helical surface 101 is provided for engaging the knitwork. The helical surface 101 of the lower needle cylinder 1 is disposed to face the lower edges of press off sinkers 8,8' or sheets 81',83,' respectively, which are received in the lower portion of supporting elements 7,7' of said upper needle cylinder 2.The height of each press-off sinker, 8,8' or of sheet 81',83 is greater, by a spacing t, than the depth of grooves D in the supporting elements 7,7' of the upper needle cylinder 2, said grooves D receiving the press-off sinkers 8,8' or the sheets 81',83 in such a way that their lower edges overlap the lower front portion of said supporting elements 7,7' in downward direction to the helical surface 101 on the lower withdrawing element 10 of the lower needle cylinder 1. In the latter there are mounted knock-over bits 4 for the stitch formation, said bits being received in a lower grooved ring 3 and being controlled by lower and upper cam rings 5,6, respectively. The press-off sinkers 8,8' are disposed in the supporting element 7 in the form of an upper grooved ring, and secured by a holding ring 9 and by its shoulder 91 by means of screws 92. The arrangement as hereinabove described is shown in Figures 1, 2 and partially also Figure 3 or, respectively, Figure 6 where the sheet 83 is shown. Figure 3 shows further an embodiment where the press-off sinkers 8' are combined with sheets 81' which are received in the same grooves and spring-loaded by means of a rubber ring 82'.

Figure 4 shows an alternative embodiment where, for an easier manufacture of the lower withdrawing element, an auxiliary ring 11 is drawn over the upper tubular portion of said element. On the front of said auxiliary ring 11 there is provided a helical groove receiving a resilient steel sheet 12 which constitutes a helical surface for engaging the knitwork, similarly as the helical surface 101 of the embodiment shown in Figures 1 and 2. In this case the sheet 12 is secured by means of a pin 120 passing through an opening in said sheet 12 and attached fixedly in a fork 122 secured by a nut (not shown) as can be seen in Figure 5.

In the variant shown in Figure 6 the supporting element 7' assumes the function of the upper withdrawing element in the grooves D of which there are mounted only the sheets 83 spring-loaded by pressure springs 81 disposed in openings 0 and bearing from above on a bearing ring 82. These sheets 83 are arranged on a part of the supporting element 7' and allowed to swing about a centre S.

In operation, when knitting the welt, the lower circular knitting element 10 is retracted in the lower inoperative position as shown in Figure 2. The knitwork grows towards the centre, since a rubber thread is being laid thereinto. After the welt has been completed, the lower circular withdrawing element 10 is displaced upwards into the operating position as is apparent from Figure 1 so that its helical surface 101 to engage the knitwork gets into a position close to the lower edges of the press-off sinkers 8,8' or sheets 81',83, respectively. Thus the rotating and growing knitwork is being "screwed", at its right side, into the helical surface 101 or, alternatively, into the helical surface produced by the steel sheet 12, and withdrawn in this way from the needles. At the back the knitwork is being guided by the lower edges of the press-off sinkers 8,8' or, alternatively, of sheets 81',83 in wale direction, said lower edges preventing the knitwork from being twisted. The sheets 83 provided only on a part of the supporting element 7' serving as the upper withdrawing element, can be arranged on said element solely in the heel formation narrowing zone, in order that said sheets 83 be allowed, if exposed to pressures of folding knitwork, to swing about the centre S and prevent thus the knitwork from being damaged.

Claims

1. A double-cylinder circular knitting machine for manufacturing hosiery, comprising a lower and an upper needle cylinder provided with longitudinal tricks in which are received latch needles and sinkers for controlling them, wherein in the lower needle cylinder there is axially disposed a lower circular withdrawing element on the upper portion of which a helical surface for engaging the knitwork is provided, wherein the helical surface of the lower needle cylinder is disposed to face lower edges of press-off sinkers or of sheets received in the lower portion of supporting elements of the upper needle cylinder.

2. A machine according to Claim 1, wherein the height of each press-off sinker or sheet is greater than the depth of groove in the supporting elements of the upper needle cylinder, in which the press-off sinkers or the sheets are disposed in such a way that the lower edges of the latter overlap the lower front portion of the upper supporting elements downwards to the helical surface of the lower circular withdrawing element.

3. A machine according to Claim 1 or 2, wherein the helical surface of the lower withdrawing element is constituted by a resilient steel sheet received in a helical groove in an auxiliary ring drawn over the upper tubular portion of said lower withdrawing element.

4. A machine according to Claim 1 or 2, wherein the sheets received in the supporting elements are springloaded.

5. A double-cylinder circular knitting machine for manufacturing hosiery constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.