EP2402491B1

EP2402491B1 - A circular knitting machine with a yarn guiding device

Info

Publication number: EP2402491B1
Application number: EP20100194036
Authority: EP
Inventors: Kuo-Chao Chao
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-06-30
Filing date: 2010-12-07
Publication date: 2013-02-13
Anticipated expiration: 2030-12-07
Also published as: EP2402491A1; TWI434969B; TW201200659A

Description

This invention relates to a circular knitting machine, more particularly to a yarn guiding device for guiding a plurality of yarns to needles of a needle cylinder of a circular knitting machine.
A conventional circular knitting machine, such as a hosiery machine, generally includes a yarn feeding and knitting mechanism, a needle selecting mechanism, a control mechanism, a transmitting mechanism, etc. As shown in Fig. 1, the yarn feeding and knitting mechanism 2 includes a yarn feeding mount 200 pivotably mounted on a sinker ring 300 disposed coaxially relative to a needle cylinder 400, a plurality of feeding fingers 202 which extend adjacent to the upper circumferential end 401 of the needle cylinder 400 and which respectively have through openings 203 for introducing at least one yarn, and a yarn guiding plate 204 disposed below the feeding fingers 202 for guiding the yarn toward the needle cylinder 400. When it is desired to change yarn, the yarn feeding mount 200 has to be turned about a pivot 205 that is transverse to both axial and radial directions to a non-working position. With such movement, it would be unavoidable for the yarn guiding plate 204 to be incidentally brought into contact with the needles (not shown) on the needle cylinder 400, which may cause needle breakage.
In US 3,975,927 , a circular knitting machine is disclosed and has a thread guide fixed to a dial cam adjacent to needles on a needle cylinder so as to keep a yarn with a predetermined thread tension.
An object of the present invention is to provide a yarn guiding device for a circular knitting machine which has a plurality of adjustable guiding fronts movable away from a needle cylinder for facilitating the task of resuming normal operation of the yarn feeding in a non-working state.
According to this invention, the yarn guiding device includes a plurality of guiding fronts, a plurality of biasingmembers, and an actuating unit. The guiding fronts are disposed upstream of needles of a needle cylinder and downstream of a corresponding yarn feeding unit in terms of a yarn feeding direction. Each of the guiding fronts has a leading marginal portion extending in a circumferential direction and, when the guiding front is in a working position, guides a yarn in a working position so as to permit the needles to take up the yarn, and a trailing actuated portion disposed radially opposite to the leading marginal portion and actuated to radially displace the guiding front into a non-working position, where the leading marginal portion is remote from the needles radially as opposed to the working position. Each of the biasing members is disposed to bias a corresponding one of the guiding fronts to move toward the working position. The actuating unit is mounted on the upper circumferential surface of the sinker ring, and is coupled with the trailing actuated portions of the guiding fronts to actuate the trailing actuated portions so as to displace the guiding fronts between the working and non-working positions.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic view of a yarn feeding and knitting mechanism of a conventional circular knitting machine;
Fig. 2 is a perspective view of the preferred embodiment of a yarn guiding device according to this invention;
Fig. 3 is an exploded perspective view of the preferred embodiment;
Fig. 4 is a fragmentary top view of the preferred embodiment, illustrating a guiding front in a working position;
Fig. 5 is a view similar to Fig. 4, illustrating the guiding front in a non-working position; and
Fig. 6 is a fragmentary top view of another preferred embodiment of a yarn guiding device according to this invention.

Before the present invention is described in greater detail, it should be noted that same reference numerals have been used to denote like elements throughout the specification.
Referring to Figs. 2 to 4, the preferred embodiment of a yarn guiding device according to the present invention is shown to be mounted on a sinker ring 10 of a circular knitting machine, such as a hosiery machine. The circular knitting machine includes a needle cylinder 100 with a cylinder axis (X), and having an upper circumferential end 101 for accommodating a plurality of needles (not shown) which are angularly displaced about the cylinder axis (X) and which are movable upwardly and downwardly of the upper circumferential end 101. The sinker ring 10 is disposed coaxially relative to the needle cylinder 100, and has an upper circumferential surface 11 extending inwardly and radially to terminate at an inner marginal region 13 that is disposed axially above and radially spaced apart from the upper circumferential end 101 of the needle cylinder 100, an annular recess 14 extending downwardly from the upper circumferential surface 11 to terminate at a recess bottom surface 141, and extending radially and outwardly from the inner marginal region 13 to terminate at an outer marginal region 142, and a plurality of guiding slots 15 which are angularly displaced from each other about the cylinder axis (X) and each of which extends radially to have inner and outer regions 151, 152 respectively proximate to the inner and outer marginal regions 13, 142. A plurality of yarn feeding units 500 angularly displaced from each other about the cylinder axis (X). Each of the yarn feeding units 500 is disposed above the upper circumferential surface 11 of the sinker ring 10 for feeding a yarn toward the upper circumferential end 101 of the needle cylinder 100. The yarn guiding device according to this embodiment is shown to comprise a plurality of guiding fronts 30, a plurality of biasing members 40, an actuating unit 20, a plurality of positioning units 50, and a driving lever 60.
Each of the guiding fronts 30 has a leading marginal portion 32 which is disposed inwardly of the inner marginal region 13 and which extends in a circumferential direction to guide a yarn in a working position so as to permit the needles on the needle cylinder 100 to take up the yarn, a trailing actuated portion 311 which is radially opposite to the leading marginal portion 32, and a guided portion 31 which is disposed between the leading marginal portion 32 and the trailing actuated portion 311 and which is disposed in and slidable radially along the respective guided slot 15 to restrict the leading marginal portion 32 to be movable only radially. The trailing actuated portion 311 has first and second surface regions 312, 313 opposite to each other in the circumferential direction, and a hole 314 formed in the radial direction.
Each of the biasing member 40 is received in the hole 314 of the respective guiding front 30 to abut against the outer region 152 and the trailing actuated portion 311 so as to bias the corresponding guiding front 30 toward the needle cylinder 100, i.e., toward the working position.
In this embodiment, the actuating unit 20 is in form of an actuating ring 20, and is rotatably mounted in the annular recess 14 to permit an outward circumferential surface 21 surrounding the cylinder axis (X) to slidably contact the outer marginal region 142 of the sinker ring 10 so as to guide turning of the actuating ring 20 about the cylinder axis (X). The outward circumferential surface 21 has a plurality of cam regions 22 respectively engaging the trailing actuated portions 311 of the guiding fronts 30. Each of the cam regions 22 has non-actuating and actuating zones 223, 222 distanced from the cylinder axis (X) by smaller and larger lengths, respectively.
Each of the positioning units 50 is affixed to the upper circumferential surface 11 of the sinker ring 10, and extends over and slidably contacts with the trailing actuated portion 311 of the respective guiding front 30 so as to stabilize the radial movement of the guiding front 30.
The driving lever 60 is pivotally mounted on the sinker ring 10 at a fulcrum 61, a weight end 63 having a groove 631 loosely engaging a pin 23 of the actuating ring 20, and a power end 62 operable to angularly move the weight end 63 so as to turn the actuating ring 20. In this embodiment, an anti-friction bearing 24 is interposed between the pin 23 and the groove 631 to facilitate the circumferential movement of the actuating ring 20.
Referring to Figs. 3 and 4, when the guiding fronts 30 are in the working position, the non-actuating zones 223 of the actuating ring 20 in a backward position are engaged with the first surface regions 312 of the respective guiding fronts 30 , thereby permitting the leading marginal regions 32 of the guiding fronts 30 to be closer to the needle cylinder 100 to maintain a predetermined tension of yarns fed by the yarn feeding units 500.
Referring to Figs. 3 and 5, when the circular knitting machine is interrupted for performing machine maintenance or yarn change, the power end 62 is operated by a power force (such as that generated by a pressure cylinder) to turn the actuating ring 20 to a forward position, where the actuating zones 222 of the actuating ring 20 are engaged with the second surface regions 313 of the respective guiding fronts 30, and thus the trailing actuated portions 311 are actuated to radially displace the guiding fronts 30 into a non-working position, where the leading marginal portions 32 are remote from the needle cylinder 100 radially against the biasing force of the biasing members 40. Thus, incidental and undesirable contact of the guiding fronts 30 with the needles on the needle cylinder 100 can be avoided.
Referring to Fig. 6, another preferred embodiment of the yarn guiding device according to this invention is shown to be similar to the previous embodiment, except that the actuating ring 20 has a plurality of antifriction bearings 25, each of which is disposed outwardly of the groove 631 and engages the weight end 63 instead of interposition between the pin 23 and the groove 631.

Claims

A circular knitting machine comprising a yarn guiding device, said circular knitting machine including a needle cylinder (100) with a cylinder axis (X), and having an upper circumferential end (101), a plurality of needles angularly displaced about the cylinder axis (X) and each disposed to be movable upwardly and downwardly of the upper circumferential end (101), a sinker ring (10) disposed coaxially relative to the needle cylinder (100), and having an upper circumferential surface (11) extending inwardly and radially to terminate at an inner marginal region (13) that is disposed axially above and radially spaced apart from the upper circumferential end (101) of the needle cylinder (100), and a plurality of yarn feeding units (500) angularly displaced from each other about the cylinder axis (X), and each disposed above the upper circumferential surface (11) of the sinker ring (10) for feeding a yarn toward the upper circumferential end (101) of the needle cylinder (100), said yarn guiding device comprising:
a plurality of guiding fronts (30), each disposed upstream of the needles and downstream of a corresponding one of the yarn feeding units (500) in terms of a yarn feeding direction, each of said guiding fronts (30) having a leading marginal portion (32) which extends in a circumferential direction and which, when said guiding front (30) is in a working position, guides the yarn so as to permit the needles to take up the yarn, and a trailing actuated portion (311) which is radially opposite to said leading marginal portion (32), characterized in that:
said trailing actuated portion (311) is actuated to radially displace said guiding front (30) into a non-working position, where said leading marginal portion (32) is remote from the needles radially as opposed to the working position;

said yarn guiding device further comprising:
a plurality of biasing members (40), each disposed to bias a corresponding one of said guiding fronts (30) to move toward the working position; and

an actuating unit (20) mounted on the upper circumferential surface (11) of the sinker ring (10), and coupled with said trailing actuated portions (311) of said guiding fronts (3) to actuate said trailing actuated portions (311) so as to displace said guiding fronts (32) between the working and non-working positions.
The circular knitting machine according to Claim 1, characterized in that said actuating unit (20) is in form of an actuating ring (20) which is turnable relative to the upper circumferential surface (11) about the cylinder axis (X) between forward and backward positions, and which has an outward circumferential surface (21) surrounding the cylinder axis (X) and having a plurality of cam regions (22) that respectively engage said trailing actuated portions (311) of said guiding fronts (30) such that, when said actuating ring (20) is turned from the backward position to the forwardposition, said guiding fronts (32) are moved from the working position to the non-working position.
The circular knitting machine according to Claim 2, characterized in that each of said cam regions (22) includes non-actuating and actuating zones (223,222) distanced from the cylinder axis (X) by smaller and larger lengths, respectively, and engaging a corresponding one of said trailing actuated portions (311) in the backward and forward positions, respectively.
The circular knitting machine according to Claim 2, characterized in that the sinker ring (10) has an annularrecess (14) extending downwardly from the upper circumferential surface (11) to terminate at a recess bottom surface (141), and extending radially and outwardly from the inner marginal region to terminate at an outer marginal region (142), and a plurality of guiding slots (15) angularly displaced from each other about the cylinder axis (X) and each extending radially to have inner and outer regions (151,152) respectively proximate to said inner and outer marginal regions (13, 142);
said actuating ring (20) being rotatably mounted in said annular recess (14) to permit said outward circumferential surface (21) to slidably contact said outer marginal region (142) so as to guide turning of said actuating ring (20);
each of said guiding fronts (30) having a guided portion (31) which is disposed between said leading marginal portion (32) and trailing actuated portion (311) and which is disposed in and slidable radially along a respective one of said guided slots (15) to restrict said leading marginal portion (32) to be movable only radially;
each of said biasing members (40) being disposed between said outer region (152) and said trailing actuated portion (311).
The circular knitting machine according to Claim 2, further characterized by a driving lever (60) pivotally mounted on the sinker ring (10) at a fulcrum (61), a weight end (63) connected to said actuating ring (20), and a power end (62) operable to angularly move said weight end (63) so as to turn said actuating ring (20) between the forward and backward positions.
The circular knitting machine according to Claim 5, characterized in that said weight end (63) has a groove (631), said actuating ring (20) having a pin (23) disposed to be loosely engaged with said groove (631) to permit turning of said actuating ring (20) when said power end (62) is operated.
The circular knitting machine according to Claim 6, characterized in that said actuating ring (20) further has a plurality of antifriction bearings (24, 25), each disposed to engage said weight end (63) for facilitating the angular movement of said actuating ring (20).
The circular knitting machine according to Claim 1, further characterized by a plurality of positioning units (50) affixed to the upper circumferential surface (11) of the sinker ring (10), and extending over and slidably contacting with said trailing actuated portions (311) so as to stabilize the radial movement of said guiding fronts (30).