Needles for knitting machines

Abstract: Damage to the head (3) and abrasion of the butt (4) of a knitting machine needle having a bridge (5) and/or stem (6) is reduced by making the bridge (5) and/or stem (6) and/or a guide piece (8) joining a bridge (5) to a stem (6) or to the neck (7) wider at the side which is nearer to the butt (4), than at the side which is farther from the butt (4) and/or, when there are more than one bridge (5) and/or more than one stem (6) and/or more than one guide piece (8), by making the width of the bridge (5), stem (6) and/or guide piece (8) which is nearer to the butt (4) wider than the bridge (5), stem (6) and/or guide piece (8) which is farther from the butt (4).

Description: The present invention relates to needles for knitting machines, especially for circular knitting machines. Knitting needles are placed with their backs contacting the needle beds of the needle grooves in a cylinder of a circular knitting machine. The knitting needles rotate at high speed as the cylinder rotates, and, at the same time, the needle butts perform high-speed reciprocating movement as they are activated by cams in fixed cam holders arranged to face the needle butts. As the knitting speed becomes faster, the force applied by the cam to the butt becomes larger, which force is transmitted to the needle head in shock waves, causing damage to the needle head. To solve this problem, it is known to be effective to provide rectilinear cutouts on the needle body, that is between the butt and the needle head, alternately from the upper side and the lower side, which gives the entire needle a meander-form by forming bridges therein (see, for example, JP-A-61-239065). It is also known to be effective to make the width of the meander-form body as narrow as possible. (In this specification and claims, "width" of a needle part means the vertical height of the needle part when placed as in the accompanying drawings.) However, by making the body narrow, there sometimes occurs damage to the needle body at a bridge portion near the butt, presumably because of the concentration of stress at such a place, where the needle body suddenly becomes narrow. The shock applied by the cam to the butt is considered to be strongest at the butt and becomes weaker in proportion to the distance from the butt, since the shock waves are gradually absorbed during its transmission in the body. The present invention, which was accomplished based on this theory, provides needles having a special configuration. FR-A-2260262 discloses a knitting machine needle having a needle body (which extends between a hook portion and a butt portion) formed by a straight, tapering front section contiguous with the hook portion and a rear section of uniform width contiguous with the butt portion in which at least part of the rear section curves along an undulating line. According to the present invention, there is provided a knitting machine needle having a head, a neck, a rectilinear meander-form needle body joining the neck to a rear portion and having at least one bridge, and at least one butt carried by the needle body, characterized in that the needle body has a part selected from (i) a bridge, (ii) a stem or (iii) a guide portion joining a bridge to a stem, which part gradually widens towards the side nearest to the butt and/or is wider than another part which is respectively another (i) bridge, (ii) stem or (iii) guide portion joining a bridge to a stem or joining a bridge to the neck, said another part extending in the same direction but spaced further from the butt than said first-mentioned part. In this specification and claims, "stem" means a part of the needle body having the same level as, but spaced from, the neck. In a first embodiment, a needle of the present invention comprises a head having a hook and a latch, a neck, at least one butt, a rear portion, at least one bridge between the head and the butt and/or between the rear portion and the butt, said bridge protruding from the level of the neck, said bridge gradually widening towards the side which is nearer to the butt. In a second embodiment, a needle of the present invention comprises a head having a hook and a latch, a neck, at least one butt, a rear portion, at least two bridges between the head and the butt and/or between the rear portion and the butt, said bridges protruding from the level of the neck, the width of the bridge which is nearer to the butt being wider than that of the bridge which is farther from the butt. In a third embodiment, a needle of the present invention comprises a head having a hook and a latch, a neck, at least one butt, a rear portion, at least one stem between the head and the butt and/or between the rear portion and the butt, said stem being at the same level as, but spaced from, the neck, the stem gradually widening towards the side which is nearer to the butt. In a fourth embodiment, a needle of the present invention comprises a head having a hook and a latch, a neck, at least one stem which is at the same level as, but spaced from, the neck, at least one bridge which protrudes from the level of the neck, at least one butt, a rear portion, at least two guide pieces which are between the head and the butt and/or between the rear portion and the butt, said guide pieces connecting the stem and the bridge, the width of the guide piece which is nearer to the butt being wider than that of the guide piece which is farther from the butt. In a fifth embodiment, a needle of the present invention comprises a head having a hook and a latch, a neck, at least one butt, a rear portion, at least two stems between the head and the butt and/or between the rear portion and the butt, said stems being at the same level as the neck, the width of the stem which is nearer to the butt being wider than that of the stem which is farther from the butt. The above-mentioned embodiments of the invention can be combined in any combination. Usually, it is advantageous to combine as many aspects as possible in a needle. Preferably, the width of the neck is 1.1 mm or less and it is wider at the side of the butt than at the side of the head. According to this invention, since the shock applied by the cam to the butt is gradually and smoothly absorbed by, for example, a stem or a bridge near the butt due to their special configurations, the head is less likely to be get damaged. Furthermore, since the shock is alleviated by this invention, the abrasion of the butt is decreased. The present invention will now be described in detail in connection with the accompanying drawings, in which: Fig. 1 shows a needle of a first example of the present invention; Fig. 2 shows a needle of a second example of the present invention; Fig. 3 shows a needle of a third example of the present invention; Fig. 4 shows a needle of a fourth example of the present invention; and Fig. 5 shows needles used in a comparison test between a needle of the present invention (a) and a prior art needle (b). Referring first to Fig. 1, the needle has a head 3 having a hook 1 and a latch 2, a neck 7, a butt 4 and a rear portion 9. The needle also has a bridge 5 between the head 3 and butt 4 and another bridge 5 between the rear portion 9 and the butt, which bridges protrude from the level of the neck 7. The bridges 5 are wider at the side 5a, which is nearer to the butt 4, than at the side 5b, which is farther from the butt 4. Referring next to Fig. 2, the needle has two bridges 5 (5c,5d) between the head 3 and butt 4 and another two bridges 5 (5c,5d) between the rear portion 9 and the butt 4. Needle stems 6, which are at the same level as the neck 7, extend between the respective pairs of bridges 5c, 5d. The bridges 5c, which are nearer to the butt 4, are wider than the bridges 5d, which are farther from the butt 4. The stems 6 are wider at the side 6a which is nearer to the butt 4, than at the side 6b, which is farther from the butt 4. Guide pieces 8 (8a,8b) connect the stems 6 to the bridges 5, and another guide piece 8 (8c) connects the bridge 5d to the neck 7. The guide piece 8c, which is farther from the butt 4, is narrower than the guide pieces 8a, which are nearer to the butt 4. The guide pieces 8b have an intermediate width. Referring next to Figs. 3 and 4, the needle has two stems 6 (6c,6d) between the head 3 and butt 4 (see Fig. 3) or two stems 6 (6c,6d) between the rear portion 9 and the butt 4 (see Fig. 4). The stems 6d, which are farther from the butt 4, are narrower than the stems 6c, which are nearer to the butt 4. In each of the above examples, the width of the neck is preferably 1.1 mm or less and, though not shown in the drawings, it is preferably wider at the side of the butt 4 than at the side of the head 3. Fig. 5 shows needles used in a comparison test between a needle of the present invention (a) and a prior art needle (b). Using 40 needles of each type in a no-load (i.e. without feeding a yarn thereto) rotation experiment, damage to the head and abrasion loss of the butt were determined. The needle of Fig. 5(a) has a weight of 0.502 g, the width of the bridge 5c is 1.2 mm, and the width of the bridge 5d is 0.9 mm. The needle of Fig. 5(b) has a weight of 0.514 g, and the width of both bridges 5c and 5d is 1.2 mm. The results are shown in the following Tables in which "H" means damage to the hook and "C" means damage to the cheek of the needle head. DAMAGE TO THE NEEDLE HEAD Number of Rotations 1 million 1.56 million 2 million Fig. 5(a) needle 0 1(H) 1(C) Fig. 5(b) needle 0 0 14(10H+4C) ABRASION LOSS AFTER 2 MILLION ROTATIONS Fig. 5(a) needle 0.33 mm Fig. 5(b) needle 0.37 mm It is apparent from the above tables that the present invention is effective in preventing damage to the head and abrasion loss of the butt.

Claims: A knitting machine needle having a head (3), a neck (7), a rectilinear meander-form needle body (5,6,8) joining the neck (7) to a rear portion (9) and having at least one bridge (5), and at least one butt (4) carried by the needle body (5,6,8), characterized in that the needle body (5,6,8) has a part selected from (i) a bridge (5), (ii) a stem (6) or (iii) a guide portion (8) joining a bridge (5) to a stem (6), which part gradually widens towards the side nearest to the butt (4) and/or is wider than another part which is respectively another (i) bridge (5), (ii) stem (6) or (iii) guide portion (8) joining a bridge (5) to a stem (6) or joining a bridge (5) to the neck (7), said another part extending in the same direction but spaced further from the butt (4) than said first-mentioned part. A needle as claimed in any one of the preceding claims, wherein the head (3) has a hook (1) and a latch (2). A needle as claimed in Claim 1 or Claim 2, wherein a bridge (5) between the head (3) and the butt (4) gradually widens towards the side (5a) which is nearer to the butt (4). A needle as claimed in Claim 1 or Claim 2, wherein a bridge (5) between the rear portion (9) and the butt (4) gradually widens towards the side (5a) which is nearer to the butt (4). A needle as claimed in Claim 1 or Claim 2 having at least two bridges (5c, 5d) between the head (3) and the butt (4), wherein the bridge (5c) which is nearer to the butt (4) is wider than the bridge (5d) which is farther from the butt (4). A needle as claimed in Claim 1 or Claim 2 having at least two bridges (5c,5d) between the rear portion (9) and the butt (4) wherein the bridge (5c) which is nearer to the butt (4) is wider than the bridge (5d) which is farther from the butt (4). A needle as claimed in Claim 1 or Claim 2 having at least one stem (6) between the head (3) and the butt (4), wherein the stem (6) gradually widens towards the side (6a) which is nearer to the butt (4). A needle as claimed in Claim 1 or Claim 2 having at least one stem (6) between the rear portion (9) and the butt (4), wherein the stem (6) gradually widens towards the side (6a) which is nearer to the butt (4). A needle as claimed in Claim 1 or Claim 2 having at least two stems (6) between the head (3) and the butt (4), wherein the stem (6c) which is nearer to the butt (4) is wider than the stem (6d) which is farther from the butt (4). A needle as claimed in Claim 1 or Claim 2 having at least two stems (6) between the rear portion (9) and the butt (4), wherein the stem (6c) which is nearer to the butt (4) is wider than the stem (6d) which is farther from the butt (4). A needle as claimed in Claim 1 or Claim 2 having at least one stem (6) and at least one bridge (5) and at least two guide pieces (8) which are between the head (3) and the butt (4), said guide pieces (8) connecting the stem (6) or neck (7) and the bridge (5), wherein the width of the guide piece (8a) which is nearer to the butt (4) is wider than the guide piece (8c) which is farther from the butt (4). A needle as claimed in Claim 1 or Claim 2 having at least one stem (6), at least one bridge (5) and at least two guide pieces (8) which are between the rear portion (9) and the butt (4), said guide pieces (8) connecting the stem (6) or neck (7) and the bridge (5), wherein the guide piece (8a) which is nearer to the butt (4) is wider than the guide piece (8b) which is farther from the butt (4). A needle as claimed in Claim 1 or Claim 2 having two or more of the features specified in Claims 3 to 12. A needle as claimed in any one of the preceding claims, wherein the neck (7) is wider at the side nearer to the butt (4) than the side further from the butt (4). A circular knitting machine comprising reciprocating knitting needles, characterized in that said needles are as claimed in Claim 1. A knitting machine as claimed in Claim 15, wherein said needles are as claimed in any one of Claims 2 to 14. The use in a circular knitting machine to absorb shock applied by a cam to a needle butt of a needle as claimed in Claim 1. A use as claimed in Claim 17, wherein the needle is as claimed in any one of Claims 2 to 14.

Inventors: KAWASE YUJI, SETA KAZUO, KAWASE, YUJI, SETA, KAZUO
Applicants: FUKUHARA NEEDLE CO LTD, FUKUHARA NEEDLE CO., LTD.
Application year: 1992
Main classification: D04B35
IPC codes: D04B35