Flat knitting machine having function for adjusting knock-over timing

Abstract: A flat knitting machine is provided capable of obtaining a high quality knit fabric excellent in knitting property (ease of knitting), by variably adjusting the knock-over timing when knitting, depending on the characteristics of knitting threads and knitted texture of the knit fabric. In the flat knitting machine sinkers (1) are planted and sinkers parallel on the top of a needle bed at specific intervals. Multiple knitting needles (4) controlled by a cam mechanism of a carriage running right and left on the needle bed are disposed free to go in and out along the sinkers. Knitting thread stopping wire rods (5) are bridged over sinkers so as to be orthogonal to the projecting direction of the knitting needles (1) beneath the projecting positions of the knitting needles (1). The abutting position of the knitting thread loop on the knitting thread stopping wire rod when knitting is made adjustable in the longitudinal direction of the sinkers, so that the knitting thread stopping wire rod (5) may be set in the sinker (1).

Description: Background of the Invention The present invention relates to a flat knitting machine having function for adjusting knock-over timing capable of adjusting the knock-over timing when knitting depending on the characteristics of knitting threads and knitted texture of knit facric. Generally, as knock-over timing of knitting in a flat knitting machine, after the knitting needle planted in the needle bed is related to a position capable of clearing the stopped former loop, the knitting thread supplied into the hook of this knitting needle is pulled in and lowed, and the new loop surpasses the former loop to form a stitch. In other words, the former loop stopped on the knitting needle is, when forming a next new loop, knocked over together with the knitting needle in its pulling-in process, so that a complete stitch is formed. This knock-over timing is automatically determined by the position of the hole drilled near the front tip of the sinker in order to install the knitting thread stopping wire rod. It means that the ratio of the sinker loop and needle loop forming the stitch to one stitch is constant in the stitches of the continuously knitted courses. However, the knock-over timing is significantly influenced by the characteristics of the knitting threads and others. For example, slipping of knitting thread, elongation, twist, dyeing property, and difference in after-treatment may affect whether the materials are same or different. They are also found to affect the shapes of the sinker loop and needle forming the stitches at the same time. French patent specification No.1564429 (SHIMA IDEA CENTER Co., LTD) discloses a general arrangement for stopping knitted thread loops by means of a wire joining sinkers. UK patent application No.GB 2120684 (Matias Mestre Mas) discloses an arrangement including an abutment arranged to push knitted loops newly formed towards a sinker in order to temporarily kink or clamp the fabric so discouraging the newly knitted loops from moving back towards the needles. The abutment is separate from the sinkers. French patent specification No.2264115 (EDOUARD DUBIED & CIE) discloses an arrangement in which a wire is used to stop knitted thread loops. Another wire 6 is present but this is not provided for discouraging threads from moving back towards the needles. No adjustment is disclosed in any of the specifications of the means for preventing movement of fabric back towards the needles. European patent No.0238797 (H Stoll GmbH & Co) also discloses an arrangement where a wire is used as in 1564429. Again no adjustment is provided. Hitherto, therefore, whenever the type or thickness of kniting thread is changed, the knitting parameters that are considered to affect the timing (thread feed tension, waxing, knit fabric winding-down tension, needle hook shape) have been revised or modified to adjust to suit knitting paramenters. This work, however, required much skill and labor, and in spite of the skill and labor spent, satisfactory results could not be obtained. The invention provides a flat knitting machine having a function for adjusting knock-over timing comprising; a plurality of sinkers fixed on a top of a needle bed at specific intervals in parallel with each other, each of said sinkers including at least one aperture near a front tip of said sinker, multiple knitting needles mounted on the needle bed and slidable along the sinkers, each of the knitting needles being controlled by a cam mechanism of a carriage running on the needle bed, characterised in that at least one knitting thread stopping wire rod (5) is provided below hook portions of the knitting needles in operation of knock-over, the knitting thread stopping wire rod or rods extending through at least one aperture (6) in the sinkers orthogonally to the sliding direction of the knitting needles, and a setting position of the knitting thread stopping wire rod in the sinkers is made adjustable (6a,6b) to enable an abutting position of a knitting thread loop on the knitting thread stopping wire rod to be changed in the sliding direction of the knitting needles. Preferably the knitting thread stopping wire rod is selectively receivable in at least one of a plurality (6a,6b) of said apertures provided near the front tip of sinkers, such that the knitting thread stopping rods position from front tip of the sinkers may be selectively adjusted. Alternatively, the knitting thread stopping wire rod is receivable in a set of communicating aperatures (7,8) near the front tip of sinkers. Desirably the knitting thread stopping wire rod has an elliptical section (5a) received in said aperture (6(6d)) near the front tip of sinker and achieving said adjustment by arbitrarily displacing the inserting angle. Brief Description of the Drawings Fig. 1 is a schematic perspective view for explaining the portion relating to the invention of a flat knitting machine, Fig. 2 is an explanatory drawing showing the knock-over state of essential parts relating to the invention, Fig. 3 is a front view showing a sinker 1a in a first embodiment, Fig.4 is an enlarged view of essential parts in Fig.3, Fig. 5 is a front view showing a sinker 1b in a second embodiment, Fig. 6 is an enlarged view of essential parts in Fig. 5, and Fig. 7, Fig. 8 are enlarged explanatory drawings of a sinker 1c in a third embodiment. Detailed Description of the Perferred Embodiments Referring now to Fig. 1 to Fig. 8, some of the preferred embodiments of the invention are described in detail below. As shown in Fig. 1, in a flat knitting machine in which sinkers 1 are planted and fixed parallel in the top of the needle bed at specific intervals, knitting needles 4 controlled by a cam mechanism of a carriage (not shown) running right and left on this needle bed through select jack 2 and jack 3 are disposed in a multiplicity, free to go in and out in the longitudinal direction of the needle bed along the sinkers 1 and needle plate 9, and knitting thread stopping wire rods 5 are bridged over the sinkers (only a part is shown herein) so as to be orthogonal to the projecting direction of the knitting needles 1, beneath the projecting position of the knitting needles 4, sinkers 1a, 1b, 1c in the individual embodiments shown in Fig. 3 to Fig. 8 are individually disposed same as the sinkers 1 in the invention, and the knitting thread stopping wire rods 5 are designed to be freely set in and out of the holes pireced in the sinkers 1a, 1b, 1c. That is, in the sinker 1a of the first embodiment as shown in Fig. 3 and Fig. 4, large and small holes 6a, 6b are pierced near the front tip of the sinker by deviating the position slightly in the longitudinal direction. In the sinker 1b of the second embodiment shown in Fig. 5 and Fig. 6, large and small communicating holes 6c in a snowman shape on the whole are opened near the front tip of the sinker as shown in the drawings. By putting the knitting thread stopping wire rods 5 into these holes 6a, 6b, holes 6c, depending on the characteristics of the knitting threads and knitted texture of knit fabric, the abutting position to the knitting thread stopping wire rod 5 of the knitting thread loop A may be changed as showned in Fig. 2, thereby making it possible to adjust to the optimun knock-over timing when the knitting thread loop A (former loop) is cleared from the hook 4a of the knitting needle 4 when forming a stitch. The embodiment shown in Fig. 7, Fig. 8 is a third embodiment, and in this embodiment, in order to adjust the knock-over timing depending on the characteristics of knitting threads and knitted texture of knit fabric, the knitting thread stopping wire rod 5 in an elliptical section is inserted in the hole 6d pierced near the front tip of the sinker 1c, and by attaching by arbitrarily varying the attaching position in the hole 6d of this knitting thread stopping wire rod 5a, that is, the inserting angle (method) of the knitting thread stopping wire rod 5a as shown in the drawing, the abutting position of the knitting thread loop A and the knitting thread stopping wire rod 5a when knitting may be properly changed in the longtudinal direction of the sinker 1c. In this embodiment, meanwhile, the hole 6d may be disposed in a plurality same as in the foregoing embodiments, or plural communicating holes may be opened, and the knitting thread stopping wire rod 5a in the elliptical shape may be set in the desired hole or in the desired position of the communicating holes. By properly setting the knitting thread stopping wire rods 5, 5a in the holes of the sinkers 1a, 1b, 1c in the foregoing embodiments, the following actions and effects may be obtained (see Fig. 2 to 6). More specifically, even in the same knitted texture, if differing in the characteristics of knitting threads, for example, in the case of the knitting thread low in stretchability or the knitting thread of excellent slipping property (small in surface friction coefficient), by setting the knitting thread stopping wire rod 5 in the hole closer to the front tip of the sinkers 1a, 1b in the first and second embodiments, a beautiful knit fabric with uniform stitches will be obtained. That is, as shown above, by setting the knitting thread stopping wire rod 5 in the hole 7 closer to the front tip of the sinkers 1a, 1b, the knock-over timing of the knitting loop A is quickened, while the stitch being formed presently is less affected by the winding-down tension. Owing to the quickness of knock-over by these characteristics of the knitting thread itself, it is possible to form the stitch more natually than in the state of easier winding-down effect by keeping the knitting thread stopping wire rod 5 away from the front tip of the needle bed (the state in which the winding-down tension may directly affect the stitch formation), and therefore the stitches become very orderly and neat, and a knit fabric of high quality may be obtained. On the other hand, even in the same knitted texture, in the case of the knitting thread high in stretchability or poor in slipping performance (large in surface friction coefficient), if knitted by setting thread stopping wire rod 5 in the hole 7 closer to the front tip of the sinkers 1a, 1b of the first embodiment and second embodiment as mentioned above, the frictional resistance increases at the contact point of the loops A and B when the new loop B rides over the former loop A (knitting thread loop A) at the time of knock-over, and the knock-over timing of the former loop A (knitting thread loop A) is delayed by the corresponding portion, and the ratio of the needle loop and sinker loop may be disturbed or the movement of the knitting thread still moving in the formed loop may be influenced, thereby adversely affecting the uniformity of the stitches. Accordingly, by setting the knitting thread stopping wire rod 5 in the hole 8 opened at a position remote from the front tip of the needle bed, stitches may be formed in a state where the winding-down tension may take effect easily, and therefore the delay of the knock-over due to poor slipping property of the knitting thread itself may be compensated by the positive utilization of the winding-down tension, and hence knit fabrics of high quality may be obtained by eliminating the above adverse effects. Next, when the knitted texture is different although the knitting threads are same, for example, in a fashioning knit for sequentially widening or narrowing the knitting width, particularly when narrowing the knitting width, if the knitting thread stopping wire rod 5 is set in the hole 8 opened at a position remote from the front tip of the sinkers 1a, 1b, the effect of the winding-down tension is large, and as the knitting width becomes narrower and narrower, it bocomes difficult to adjust the winding-down tension, and it also becomes difficult to reduce the stitches at both ends of the knit fabric, further it is likely to be broken. Accordingly, by setting the knitting thread stopping wire rod 5 in the hole 7 opened at a position close to the front end of the sinkers 1a, 1b, the effect of the winding-down tension becomes less, and therefore even if some strong winding-down tension is actuated, the chance of immedicate adverse effect on the knit fabric is low. On the other hand, even by the same knitting threads, in the case of knitted texture mixing rib stitch and plain stitch at various locations in the wale direction such as in the knit-in pattern, if the knitting thread stopping wire rod 5 is placed in the hole 7 made at a position closer to the front tip of the sinkers 1a, 1b, as known from the example above, the winding-down tension hardly acts on the knit fabric, and hence the plain stitch loop in a loosened state as compared with the rib stitch loop may finally lead to double biting even if knocked over from the hook part of the needle front end. Accordingly, by setting thread stopping wire rod 5 in the hole 18 drilled at a position remote from the front tip of the sinkers 1a, 1b, the effect of the winding-down tension is increased, and such double biting may be avoided, and a knit fabric of excellent high quality may be obtained. Incidentally, in order to obtain the above action and effect by the sinker 1a and knitting thread stopping wire rod 5a in the third embodiment, as mentioned above, instead of setting the knitting thread stopping wire rod 5 in the hole 8 made in a position remote from the front the front end of the sinkers 1a, 1b, for example, the knitting thread stopping wire rod 5a which has an elliptical section may be inserted as shown in Fig. 7, so that the same action and effect may be obtained. Moreover, instead of setting the knitting thread stopping wire rod 5 in the hole 7 opened in a position close to the front tip of the sinkers 1a, 1b, for example as shown in Fig. 8, by inserting the knitting thread stopping wire rod 5a which has an ellipical section, the same action and effect may be obtained.

Claims: A flat knitting machine having a function for adjusting knock-over timing comprising; a plurality of sinkers fixed on a top of a needle bed at specific intervals in parallel with each other, each of said sinkers including at least one aperture near a front tip of said sinker, multiple knitting needles mounted on the needle bed and slidable along the sinkers, each of the knitting needles being controlled by a cam mechanism of a carriage running on the needle bed, characterised in that at least one knitting thread stopping wire rod (5) is provided below hook portions of the knitting needles in operation of knock-over, the knitting thread stopping wire rod or rods extending through at least one aperture (6) in the sinkers orthogonally to the sliding direction of the knitting needles, and a setting position of the knitting thread stopping wire rod in the sinkers is made adjustable (6a,6b) to enable an abutting position of a knitting thread loop on the knitting thread stopping wire rod to be changed in the sliding direction of the knitting needles. A flat knitting machine having a function for adjusting knock-over timing as claimed in claim 1, characterised in that a knitting thread stopping wire rod is selectively receivable in at least one of a plurality (6a,6b) of said apertures provided near the front tip of sinkers, such that the knitting thread stopping rods position from front tip of the sinkers may be selectively adjusted. A flat knitting machine having function for adjusting knock-over timing according to claim 1, characterised in that at least one thread stopping wire rod is receivable in a set of communicating aperatures (7,8) near the front tip of sinkers. A flat knitting machine having function for adjusting knock-over timing according to claim 1, characterised in that the knitting thread stopping wire rod has an elliptical section (5a) received in said aperture (6(6d)) near the front tip of sinker and achieving said adjustment by arbitrarity displacing the inserting angle.

Inventors: KUBOTA RYOICHI, NAKAHARA SHIGEKI, WADA TAKASHI, KUBOTA, RYOICHI, NAKAHARA, SHIGEKI, WADA, TAKASHI
Applicants: SHIMA SEIKI MFG, SHIMA SEIKI MFG., LTD.
Application year: 1991
Main classification: D04B7
IPC codes: D04B7, C07C13, C07B61, D04B15, B01J21, C07C1