Sinker mechanism for flat knitting machines

Abstract: A sinker (27) is disposed at the front end of the needle bed (2) of a flat knitting machine so as to be capable of swing displacement. A groove (4) for guiding the advancing, retreating and swing motion of the sinker (27) forming a knitting yarn holding part (29) at the front end of a sinker plate (28), is formed at the front end of the needle bed, and a knitting yarn drop preventive part (37), for preventing the knitting yarn (43) applied between the knitting needle (7) and sinker (27) from dropping into the groove (4) during knitting, is disposed adjacently to the sinker (27).

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sinker mechanism disposed at the front end of a needle bed of a flat knitting machine, provided with at least a pair of needle beds, on which a plurality of knitting needles are silidably planted in parallel, and which disposed oppositely in front and rear positions. 2. Description of the Related Art As a prior art of a sinker mechanism disposed at a needle bed front end of a flat knitting machine, US-A-5,134,865 proposed previously by the present applicant, the international publication WO-A-8 912 708, and others have been known. In the former art, an approximately arc-shaped loop forming edge is formed in the sinker main body at the front end portion of the needle bed, and a knitting yarn holding part is formed ahead thereof, and a guide groove for guiding the sinker to move forward and backward and swing with respect to the opening is formed at the needle bed front end, and when the sinker swings forward in the guide groove, the knitting yarn holding part is caused to swing into a deep position beneath the opening gap of the needle bed, and by pushing the sinker loop of the previous course, the loop of the previous course is prevented from floating with the knitting needle when the knitting needle advances, so that loop may be formed continuously. In the latter art, on the other hand, a comb bed is placed above the front end of the needle bed, and a comb jack, which is capable of swinging, is pivoted in a wire stretched in the longitudinal direction of the needle bed above the comb bed. The comb jack comprises a lever for adjusting the swing extent by the cam provided in the carriage in the rear part, and an elastic leg for thrusting the comb jack in the stitch pushing direction. At the front end portion of the comb jack, a hole is formed so that the comb jack can swing, with the wire stretched in the comb bed longitudinal direction being inserted. The comb jack swings, resisting the force of the elastic leg from the state of pushing the stitch in the deep position, by the activation of the cam provided in the carriage, and is designed to apply a tension to the former loop depending on the length of the stitch. However, in US-A-5,134,865, as mentioned above, since knitting is performed in the state in which the gap between the sinker and the guide groove for guiding the swing motion of the sinker is exposed on the needle bed, in the case of fine gauge knitting machine with a small needle pitch, in the case of pulling the knitting needle largely with the sinker pushed into a deep position, or in the case of knitting a pattern in which the tension of the knitting yarn applied between the knitting needle and sinker is intensified, the knitting yarn may fall in and be broken in the gap between the sinker and the sinker guide groove, or other troubles might occur. In WO-A-8 912 708, since the wire is disposed in the longitudinal direction of the comb floor at the front end portion of the comb floor, such problem does not occur. However, the hole for inserting the wire must be pierced in the front end portion of the comb jack, and the thickness is reduced in the knitting yarn holding part of the sinker, which involved a problem in strength. SUMMARY OF THE INVENTION Considering the above problems, it is hence a primary object of the present invention to provide a sinker mechanism capable of sufficiently pushing the former loop without sacrificing the strength of the sinker, and preventing the knitting yarn from dropping into the gap between the sinker and the sinker guide groove. To achieve this object, the invention presents a sinker mechanism for a flat knitting machine, having at least a pair of needle beds, on which a plurality of knitting needles being slidably planted in parallel, disposed oppositely in front and rear positions, wherein each needle bed is provided with sinker capable of advancing, retreating and rocking with respect to the opening of the needle bed, a knitting yarn holding part is formed at the front end portion of each sinker, a sinker guide each for guiding the sinker front end portion during swing of the sinker is formed in the needle bed, and a knitting yarn drop preventive part for preventing the knitting yarn applied between the knitting needle and sinker from dropping into the gap between the sinker and sinker guide groove during knitting is provided at the needle bed front end portion adjacently to the sinker. Moreover, a support plate is laminated with a sinker on each needle plate planted on the needle bed, and the front end of the support plate is extended to the front end portion of the needle bed, thereby forming the knitting yarn drop preventive part. Furthermore, the front end portion of the knitting yarn drop preventive part formed on the support plate is extended until penetrating into a long groove formed in the longitudinal direction of the needle bed in the front end portion of the needle bed. It is other feature that the front end portion of the support plate penetrating into the long groove formed in the longitudinal direction of the needle bed is extended further by bending in the long groove so as to be orthogonal to the sliding surface of the corresponding knitting needle, and that the extended portion is bent before the sinker of the other side confronting the knitting needle so as to stand along the sinker, thereby forming the knitting yarn drop preventive part at both sides of the knitting needle. Besides, a part of the sliding surface of the knitting needle at the front end side of the needle bed including the needle bed front end portion is cut off, and the knitting yarn drop preventive part is formed along the sinker, in the cut-off portion, at least at one of the sides of the front end portion. The knitting yarn drop preventive part is formed integrally as part of the needle bed. According to another feature, the knitting yarn guide part disposed above the knitting yarn drop preventive part is formed so as to be located above the knitting yarn holding part when the movable sinker swings and the knitting yarn holding part descends, being projected to the vicinity side of the middle position of the opening gap from the front end peripheral edge of the sinker plate overlapping with the knitting yarn guide surface, and the portion of forming the peripheral edge of the knitting yarn guide surface is formed in a form of covering the outside of the front end of the needle bed in a side view, and the knitting yarn guide surface is formed so that the terminal end of the knitting yarn guide surface is formed at the height position of the tracing drawn by the center of the hook of the knitting needle when it retreats on the needle bed or at lower position. In the sinker mechanism for a flat knitting machine according to the invention, the knitting yarn holding part is formed at the front end portion of the movable sinker. When the sinker swings forward, the knitting yarn holding part is made to swing into a deep position beneath the opening gap of the needle bed, and the loop of the former course is pushed in, and a new loop is formed. For example, in case of a knitting machine of fine gauge with a small needle pitch, or when the knitting needle is pulled in largely with the sinker being pushed into a deep position, or in the case of forming a pattern so as to increase the tension of the knitting yarn applied between the knitting needle and the sinker, the knitting yarn is guided by the knitting yarn drop preventive part, and is hence held without being dropped into the gap between the sinker and sinker guide groove. Furthermore, in case of forming a knitting yarn guide surface above the knitting yarn drop preventive part, when the knitting yarn is supplied into the hook of the adjacent knitting needle over the front end of the sinker, with the formed loop being stopped by the knitting needle, it abuts against the knitting yarn guide surface projecting from the swing trace of the movable sinker, and it slides down on this surface, so that the knitting yarn is extended from the lower edge of the knitting yarn guide surface to a lower position of the yarn feeder, so as to be securely guided into the hook of the knitting needle, thereby preventing from passing above the hook of the knitting needle at the same time. As described herein, the sinker mechanism for a flat knitting machine of the invention comprises a guide groove for guiding the advancing, retreating and swing of the sinker disposed at the front end portion of the needle bed, and in the guide groove, the movable sinker with the knitting yarn holding part formed at the front end is pushed into a deep position while stopping the former loop, thereby forming a new loop, so that knitting is performed while sufficiently holding down the loop. Furthermore, for example, in case of a knitting machine of fine gauge with a small needle pitch, or in case that a knitting needle is pulled in largely with the sinker being pushed into a deep position, or in case of forming a pattern so as to increase the tension of the knitting yarn applied between the knitting needle and the sinker, the knitting yarn is guided by the knitting yarn drop preventive part, and is hence held without being dropped into the gap between the sinker and sinker guide groove. Therefore, it is not necessary to dispose a wire in the longitudinal direction at the front end portion of the needle bed, and hence the hole for swing motion in the inserted state of the wire into the sinker front end portion is not needed, so that the problem of sacrifice of strength of sinker as experienced in the prior art may not occur. Incidentally, in case of disposing the knitting yarn guide surface above the knitting yarn drop preventive part, the supplied yarn is guided downward by the knitting yarn guide surface, and therefore the former loop can be sufficiently held down by the movable sinker, and hence even in case of forming loops of loose stitches, it is beneficial to prevent over-stitching securely by accurately clearing the former loop from the latch. Moreover, the knitting yarn supplied to the hook of the adjacent knitting needle over the front end of the sinker is prevented from sliding above from around the loop forming edge of the sinker, and the knitting yarn supplied to the knitting needle can be securely received on the hook. Hence, the loop is formed securely, and a knit fabric of high quality may be presented. BRIEF DESCRIPTION OF THE DRAWINGS Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein: Fig. 1 is a side view of essential parts showing a schematic constitution of a flat knitting machine. Fig. 2 is an exploded view of sinker unit. Fig. 3(A) is a side view of sinker unit. Fig. 3(B) is a sectional view of the line X-X in Fig.3(A). Fig. 4 is a sectional view of the line Y-Y in Fig. 3(A). Fig. 5 is a schematic developed view showing the function of the parts for controlling knitting needle and sinker of carriage. Fig. 6 is a side view of sinker unit. Fig. 7 is a side view of sinker unit when the sinker is at the position A in Fig. 5. Fig. 8 is a side view of sinker unit when the sinker is at the position B in Fig. 5. Fig. 9 is a side view of sinker unit when the sinker is at the position C in Fig. 5. Fig. 10 is a side view of sinker unit when the sinker is at the position D in Fig. 5. Fig. 11 is a side view of sinker unit when the sinker is at the position E in Fig. 5. Fig. 12 is a side view of sinker unit when the sinker is at the position F in Fig. 5. Fig. 13 is a perspective view showing other method of embodiment of the invention. Fig. 14 is a perspective view showing a second embodiment of the invention. Fig. 15(A) is a side view of sinker unit in the second embodiment of the invention. Fig. 15(B) is a sectional view of the line W-W in Fig. 15(A). Fig. 16 is a perspective view of knitting yarn drop preventive part in a third embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Now referring to the drawing, preferred embodiments of the invention are described below. Fig. 1 is a side view showing a schematic constitution of a flat knitting machine, in which reference numeral 1 indicates a flat knitting machine as a whole. In this flat knitting machine 1, on needle beds 2, needle plates 6 as shown in Fig. 2 are disposed at equal intervals, and between the needle plates 6, 6, plural latch type knitting needles having an elastic guide piece 8 for stitch transfer at the side surface are disposed in parallel so as to be capable of moving forward and backward, and at least a pair of the needle beds 2 are disposed in front and rear positions, in a confronting state across line A, in the state of mutual approaching of the front end portions of the knitting needles. At the front end portion of the needle beds, movable sinkers 27 described later are disposed, and guide grooves 4 for guiding the advancing, retreating and swing of the movable sinkers 27 with respect to the opening are provided. An opening gap T is formed between the front ends of the needle beds 2, 2, and the knitting yarn is supplied from the yarn feeder 44. Knitting needles 7 of the both needle beds 2 are made to move forward and backward by a carriage 9. As the entire structure of the flat knitting machine 1, it is assumed that the forward direction is the front side and the backward direction is the back side. In each needle bed 2, it is however assumed that the forward is the advancing direction of the knitting needle 7, and the backward is the retreating direction. Fig. 5 is a developed view showing the outline of a cam group of the carriage 9 provided for forward and backward operation of the knitting needle 7 of the needle bed 2 and for swinging the movable sinker 27 described below. Numeral 10 denotes a knitting cam, 11 is a rear cam for sinker control disposed ahead of the knitting cam 10, and 12 is a front cam for sinker control disposed ahead of the rear cam 11. The front cam 12 for sinker control forms a cam profile 13 in the lower surface of one plate. The rear cam 11 for sinker control is composed by disposing movable cams 16, 17, 18, 19 thrust to the projection side by spiral spring 15 on a plate forming a cam profile 14 in the lower surface. The front cam 11 and rear cam 12 for sinker control are respectively fixed by fixing bolts 21, 22 to a bracket 20 projecting from the carriage main body (Fig. 6). Of the movable cams 16, 17, 18, 19, the cams 16, 18 at one side are for going stroke, and the cams 17,19 at the other side are for returning stroke. The knitting cam 10 comprises a hill-shaped needle raising cam 23, a guard cam 24 disposed above the middle of the needle raising cam 23, and stitch cams 25, 25 disposed slidably along the side surface at both sides of the guard cam 24, and a control groove 26a in which a butt 26 of the knitting needles 7 passes is formed among the needle raising cam 23, guard cam 24 and stitch cams 25, 25. As shown in Fig. 2, the needle plate 6 is planted on the top surface of the needle bed 2. The knitting needles 7 controlled by the knitting cam 10 are slidably disposed forward and backward, between the needle plates 6, 6, in the state of the hook 7a at the front end projecting outward from the front end of the needle bed 2, and the state if withdrawing in. The movable sinker 27 is attached to the needle plate 6, and a spacer 36 is disposed above each knitting needle 7. The hook 7a is opened and closed by a latch 45. Fig. 3(A) specifically shows the portion of the sinker 27, and Fig. 3(B) shows the state as seen from the sectional line X-X in Fig. 3(A). In the movable sinker 27, as shown in Fig. 2 and Figs. 3(A), 3(B), a sinker plate 28 formed of a thin plate is installed in laminate state together with a support plate 34, between the needle plate 6 and a spacer 36 disposed above the knitting needle 7, and it is designed to be mainly controlled led in swing by the front cam 12 and rear cam 11. At the front end of the sinker plate 28, a knitting yarn holding part 29 for receiving the knitting yarn is formed, and slightly behind the knitting yarn holding part 29, a front cam abutting part 30a to which the front cam 12 for sinker cam abuts is formed, and near the front cam abutting part 30a, a spring stopping part 32 for stopping an end of a wire spring 31 in an approximately U form for pushing down and thrusting the knitting yarn holding part 29 is formed. Behind the spring stopping part 32 of the sinker plate 28, a rotary pivot part 33 projecting downward in a semicircle is formed, and a rear cam abutting part 30b to which the rear cam 11 abuts is formed at the rear end portion. The needle plate 6 on which the sinker plate 28 is mounted is formed in a thin wall by cutting off the upper half 6a of one side of the portion closest to the front end, by the portion of sum of thickness of the sinker plate 28 and support plate 34 described below. In the middle position of the portion 6a formed in a thin wall, in the lower half 6b of the thickness, a semicircular recess for bearing 35 is pierced. In this sinker 27, the rotary pivot part 33 is supported in the recess for bearing 35, and other parts are capable of swing and contained in a slit space formed by the thin wall part of the needle plate 6 and the support plate 34. The support plate 34 is formed of a thin steel plate, and the rear end portion forms a recess for fitting 47 for fitting into a rotary pivot rod 46 supported by penetrating through the needle plates 6, 6..., and a dovetail engaging groove 42 mentioned later is formed in the middle part, and is formed nearly in the same shape as the spacer 36. Ahead of the support plate 34, a knitting yarn drop preventive part 37 of the invention is projecting downward. The front end of the knitting yarn drop preventive part 37 formed integrally as the front end portion of the support plate 34 is penetrating into a long groove 5 formed on the needle bed in the longitudinal direction of the needle bed, and it is constituted so that the stitch loop stopped by the knitting needle 7 may be prevented from falling into the gap between the movable sinker 27 disposed adjacently to the knitting needle 7 and the sinker guide groove 4. In this embodiment, by penetrating the front end portion of the knitting yarn drop preventive part 37 into the groove 5, it is advantageous that the front end of the knitting yarn drop preventive part 37 can be supported securely in the case of knitting by using a thick knitting yarn as in a coarse gauge knitting machine, or in the case of knitting by applying a large tension to the knitting yarn. In the embodiment, the knitting yarn drop preventive part 37 is formed on the support plate 34, and a knitting yarn guide 40 is formed toward the opening gap T, above the knitting yarn drop preventive part 37. This knitting yarn guide 40 is projected downward obliquely from the bottom 38 of the rear half of the support plate 34. The front end portion of the support plate 34 forming a knitting yarn guide surface 39 is close to the middle position A of the opening gap of the needle beds 2, 2 shown in Fig. 1, and is formed in a state of projecting from the arc-shaped front end surface 28a of the sinker plate 28. The portion formed as the knitting yarn guide surface 39 is in a shape of covering outward the front end of the needle bed 2 in a side view, and is formed, as shown in Fig. 8, so that its terminal end portion 39a may be located at the height position of the trace Z drawn by the center C of the hook 7a when the knitting needle 7 retreats on the needle bed 2. Fig. 4 is shows a state as seen from the sectional line Y-Y in Fig. 3(A). This diagram also shows the state of configuration of the parts as seen from the sectional line IV-IV in Fig. 2 in the specified positions. When a holder plate 41 is inserted into an engaging groove 42 formed on each top surface of the needle plate 6, spacer 36 and support plate 34, the spacer 36 and support plate 34 are fixed. At the same time, at the lower surface of the holder plate 41, a free end portion 31a of the wire spring 31 is pushed down and thrust, and the knitting yarn holding part 29 at the front end of the sinker plate 28 is always pushed down and thrust. In thus composed flat knitting machine, the operation of the sinker mechanism is described below. In Fig. 5, by moving the carriage 9 from right to left, when the movable sinker 27 comes to the position of A in the drawing, with the knitting needle 7 drawn in from the front end of the needle bed 2 as shown in Fig. 7, the movable sinker 27 abuts against the front cam abutting part 30a by the front cam 12 for sinker control, and the rear cam abutting part 30b is pushed down by the movable cam 16 of the rear cam 11. The sinker plate 28 rotates counterclockwise in the drawing, about the center of rotation of the rotary pivot part 33 fitted to the recess 35 for bearing, and the knitting yarn holding part 29 at the front end of the sinker plate 28 is positioned above the knitting needle 7. Consequently, when the movable sinker 27 comes to the position of B in Fig. 5, as shown in Fig. 8, the butt 26 is slightly pushed up by the needle raising cam 23, and the hook 7a of the knitting needle 7 is slightly projected from the front end of the needle bed 2. On the other hand, the movable sinker 27 rotates clockwise in the drawing by the elastic force of the wire spring 31, and is pushed downward of the knitting needle 7, with the knitting yarn 43 of former loop held in the knitting yarn holding part 29 at the front end. As the carriage 9 further runs leftward until the sinker 27 comes to the position C in Fig. 5, the butt 26 of the knitting needle 7 is largely pushed up to the peak of the needle raising cam 23, and the hook 7a is largely projected from the front end of the needle bed 2 as shown in Fig. 9. Herein, concerning the movable sinker 27, in the balanced state of the tension of the knitting yarn 43 of the former loop arrested on the knitting yarn holding part 29 at the front end and the elastic force of the wire spring 31, the wire spring 31 for pushing in is held in the detent part 32, and the knitting yarn 43 of the former loop rides over by pushing to open the latch 45 of the hook 7a. At this time, if the tension of the knitting yarn 43 of the former loop arrested on the knitting yarn holding part 29 is elevated, depending on the elevated tension, the knitting yarn holding part 29 rocks upward to absorb it, so that the tension of the knitting yarn 43 of the former loop arrested on the knitting yarn holding part 29 is maintained approximately the specified tension. As the carriage 9 moreover runs leftward until the movable sinker 27 comes to the position D in Fig. 5, as shown in Fig. 10, with the knitting yarn 43a supplied from a yarn feeder 4 engaged with the hook 7a of the knitting needle 7, the butt 26 of the knitting needle 7 shown in Fig. 5 is pushed down by the guard cam 24. At this time, the movable sinker 27 rotates counterclockwise in the drawing about the center of rotation of the rotary pivot part 33 as the rear cam abutting part 30b of the sinker plate 28 is pushed down by the movable cam 18 of the rear cam 11, and the knitting yarn holding part 29 at the front end of the sinker plate 28 climbs up nearly to the knitting needle 4. and therefore the knitting yarn 43 of the former loop is released from the hook 7a, thereby coming in the knock-over waiting position outside the latch 45. When the sinker 27 comes to the position E in Fig. 5, the butt 26 of the knitting needle 7 is further pushed down by the stitch cam 25, and the latch 45 is closed, the knitting yarn 43 of the former loop is knocked over, and the hook 7a is withdrawn from the front end of the needle bed 2 (see Fig. 11). . Herein, the knitting yarn 43a sequentially supplied from the yarn feeder 44 to the hook 7a of the adjacent knitting needle 7 over the front end of the movable sinker plate 27 abuts against the knitting yarn guide surface 39 formed at the front end portion of the support plate 34, and slides down on this surface 39 to the position (the height position of the trace Z drawn by the center C of the hook 7a of the knitting needle 7) of its terminal end portion 39a, so that the knitting yarn 43a is extended from this low position to the yarn feeder 44, thereby securely feeding the yarn to the hook 7a of the knitting needles 7, 7. --- at the lower side in the running direction of the carriage 9. In the process of transferring from the position of D to the position of E, along with the advancing and retreating action of the knitting needles 7, the knitting yarn 43 of the former loop riding over the latch 45 of the hook 7a, the latch 45 of the hook 7a is closed, and it is knocked over as riding over the top surface of the closed latch 45, and the loop to be knocked over is largely extended when the hook 7a passes through it, and therefore the tension of the knitting yarn 43 of the former hoop arrested on the knitting yarn holding part 29 at the front end of the sinker plate 27 is going to be abnormally high. With this tension going abnormally high, resisting the elastic thrusting force of the wire spring 31, the sinker plate 28 rotates counterclockwise in the drawing about the center of rotation of the rotary pivot part 33 to relax the high tension, so that the tension of the knitting yarn 43 detected on the knitting yarn holding part 29 can be maintained nearly at the specified tension. Supposing the position of D shown in Fig. 10, for example, with the rear cam abutting part 30b of the sinker 27 pushed in to a deep position, the knitting needle 7 is largely pulled in, and the tension of the knitting yarn 43 applied between the knitting needle 7 and the sinker 27 is heightened. The knitting yarn 43 is easy to invade into the guide groove 4 for guiding the movable sinker 27 to advance, retreat and swing with respect to the opening, but since it is guided by the knitting yarn drop preventive part 37 standing in the invading route, it is prevented from getting into the gap between the sinker 27 and sinker guide groover 4. Therefore, it is possible to prevent inconveniences such as dropping and cutting of the knitting yarn 43 in the groove 4 for guiding sinker. When the carriage 9 further runs leftward until the movable sinker 27 reaches the position F in Fig. 5, the butt 26 of the knitting needle 7 is slightly raised from the position of E in the bottom of the stitch cam 25, and accordingly, as shown in Fig. 12, the hook 7a of the knitting needle 7 slightly advances to the front end side of the needle bed 2, attempting to loosen the knitting yarn 43 of the former loop engaged with the hook 7a, but the knitting yarn holding part 29 is pushed in downward by the elastic force of the wire spring 31, thereby preventing from loosening. Therefore, stitch skip due to loosening of the knitting yarn 43 of the former loop engaged with the hook 7a may be avoided. This embodiment comprises the support plate 34 forming the knitting yarn drop preventive part 37 only at one side of the sinker 37 positioned at both sides of the knitting needle 7. In this embodiment, as shown in Fig. 3(B), using the knitting needle 7 having the elastic guide piece 8 for stitch transfer on the side surface, of the needle plates 6, those confronting the elastic guide piece 8 for stitch transfer are cut off and a space for accommodation is provided, and therefore the knitting needle 7 itself is at a position shifted to the opposite direction from the positioned side of the guide piece 8, and the angle formed by the knitting yarn 43 applied between the knitting needle 7 and the sinker 27 and the sinker plate 28 is different between right and left sides. Therefore, the knitting yarn 43 is provided only at the smaller side of the angle which is easier to fall into the guide groove 4. Incidentally, the support plate 34 forming the knitting yarn drop preventive part 37 may be disposed at both sides of each sinker plate 28, and in this case, advantageously, the knitting yarn drop preventive parts 37 may be formed on both sides. Besides, as shown in Fig. 13, the front end portion of the support plate 34 fixed on the needle bed 2 can be further bent and extended so as to be orthogonal to the sliding surface of the corresponding knitting needle 7 in the groove 5, and the extended part 37a may be set up along the sinker 27 before the sinker 27 of the other side confronting across the knitting needle 7, and the knitting yarn drop preventive part 37 may be formed at both sides of the knitting needle 7 by using one support plate 34. Alternatively, by cutting off the front end portion of the needle bed instead of the groove 4, the front end of the knitting yarn drop preventive part 37 may be positioned in the cut-off area. In the second embodiment of the invention shown in Fig. 14 and Fig. 15, a part of the knitting needle sliding surface at the front end side of the needle bed 2 including the front end of the needle bed 2 is cut off. In the cutoff area, as a part of the sliding surface of the knitting needle, the side part of the front end portion of the support plate 49 disposed on the needle bed 2 is bent right and left so as to be adjacent to the sinker plate 28, and the bent portions are used as knitting yarn drop preventive parts 50a and 50b, and these knitting yarn drop preventive parts 50a, 50b are disposed at both sides. In this case, in order that the support plate 49 may not slip out of the needle bed due to moving or floating during operation of the knitting machine, the tail of the support plate 49 is bent in the groove direction over the longitudinal direction of the needle bed to form a engaging part 52, and the engaging part 52 is engaged with the groove 3 provided in the longitudinal direction of the needle bed, and moreover the rear end surfaces 51a and 51b of the knitting yarn drop preventive parts 50a and 50b at the front end portion of the support plate 49 are caused to abut against the upper half 6a of the needle plate, thereby fixing the position. Moreover, according to the third embodiment of the invention shown in Fig. 16, the portion adjacent to the guide groove 4 of the sinker 27 at the front end of the needle bed 2 may be formed much higher. Using the higher portion as a knitting yarn drop preventive part 53, the invention may be also realized by forming it integrally as a part of the needle bed 2. The invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims only.

Claims: A sinker mechanism for a flat knitting machine, having at least a pair of needle beds (2), on which a plurality of knitting needles (7) being slidably planted in parallel, disposed oppositely in front and rear positions, wherein each needle bed (2) is provided with sinker (27) capable of advancing, retreating and swing with respect to the opening of the needle bed (2), a knitting yarn holding part (29) is formed at the front end portion of each sinker (27), a sinker guide groove (4) for guiding each sinker front end portion during swing of the sinker is formed in the needle bed (2), characterised in that a knitting yarn drop preventive part (37,50a,50b,53) for preventing the knitting yarn (43) applied between the knitting needle (7) and sinker (27) from dropping into the gap between the sinker (27) and sinker guide groove (4) during knitting is provided at the needle bed front end portion adjacently to the sinker (27). A sinker mechanism for a flat knitting machine according to claim 1, wherein needle plates (6) are planted on the needle bed (2), a support plate (34) is laminated with a sinker (27) on each needle plate (6), and the front end of the support plate (34) is extended to the front end portion of the needle bed (2), thereby forming the knitting yarn drop preventive part (37). A sinker mechanism for a flat knitting machine according to claim 2, wherein a long groove (5) is formed at the front end portion of the needle bed (2) over the longitudinal direction of the needle bed (2), and the front end portion of the knitting yarn drop preventive part (37) formed on the support plate (34) is formed by extending until penetrating into the long groove (5). A sinker mechanism for a flat knitting machine according to claim 3, wherein the front end portion of the support plate (34) penetrating into the long groove (5) formed in the longitudinal direction of the needle bed (2) is extended further by bending in the long groove (5) so as to be orthogonal to the sliding surface of the corresponding knitting needle (7), and that the extended portion (37a) is bent before the sinker (27) of the other side confronting the knitting needle (7) so as to stand along the sinker (27), thereby forming the knitting yarn drop preventive part (37) at both sides of the knitting needle (7). A sinker mechanism for a flat knitting machine according to claim 1, wherein a part of the sliding surface of the knitting needle (7) at the front end side of the needle bed (2) including the needle bed front end portion is cut off, and the knitting yarn drop preventive part (50a,50b) is formed at the front end side of a support plate (49) along the sinker plate (28), in the cut-off portion, at least at one of the sides of the front end portion. A sinker mechanism for a flat knitting machine according to claim 1, wherein the knitting yarn drop preventive part (53) is formed integrally as a part of the needle bed (2). A sinker mechanism for a flat knitting machine according to any one of the preceding claims, wherein a knitting yarn guide surface (39) is provided above the knitting yarn drop preventive part (37), and the knitting yarn guide surface (39) is in a state of projecting to the neighboring side of the middle position (A) of the opening gap (T) from the trace drawn by the front end peripheral edge (28a) of the movable sinker (27) when the movable sinker (27) swings, and the peripheral edge of the knitting yarn guide surface (39) is located at a position lower than the height of the trace (Z) drawn by the center (C) of the hook (7a) of the knitting needle (7) when it moves in and out on the needle bed (2).

Inventors: KYOTANI MINORU, YABUTA MASAHIRO, KYOTANI, MINORU, YABUTA, MASAHIRO
Applicants: SHIMA SEIKI MFG, SHIMA SEIKI MFG., LTD.
Application year: 1993
Main classification: D04B15
IPC codes: D04B15