Stitch increasing method and cams for flat knitting machine having stitch increasing function

Abstract: A method of stitch increasing is characterised in that, among compound needles inserted in needle grooves of first and second needle beds disposed with ends thereof opposed to each other, that needle in either one of said first and second needle beds which has a loop carried thereon is raised to a transfer position, and then another needle in the opposing needle bed is raised until it is inserted into the loop carried on the former needle, whereafter the two needles are lowered to cause the knitted fabric loop to be caught by the hook of the latter needle, and that when the needle which has been lifted to the transfer position is lowered, the loop carried on the needle being lowered is caught again in the hook of the needle being lowered so that the loop extends between the needles in said first and second needle beds. Needle operating cams to enable the stitch increasing method to be performed are also described.

Description: The present invention relates to a stitch increasing method for increasing a stitch during the forming of stitches and to a needle operating cam which can increase a stitch. Conventionally, when a knitted fabric is to be knitted by hand, such stitch increasing as is illustrated in Fig. 18 (the example shown is left stitch increasing; right stitch increasing is similar) and such casting-on stitch increasing as is shown in Fig. 19 are known. This is used when, for example, the knitting width is to be increased as in fashioning or when an Aran pattern is to be produced or the like. However, an automatic knitting machine on which such knitting methods can be effected has not heretofore been known. It is an object of the present invention to provide an automatic knitting machine which can effect stitch increasing which has not conventionally been achieved on an automatic knitting machine. According to the method of the present invention, among compound needles inserted in needle grooves of first and second needle beds disposed with ends thereof opposed to each other, that needle in either one of the first and second needle beds which has a loop carried thereon is raised to a transfer position, and then another needle in the opposing needle bed is raised until it is inserted into the loop carried on the former needle, whereafter the two needles are lowered to cause the knitted fabric loop to be caught by the hook of the latter needle, and then, when the needle which has been lifted to the transfer position is lowered, the loop carried on the needle being lowered is caught again in the hook of the needle being lowered so that the loop extends between the needles in the first and second needle beds. Also according to the present invention, there is provided a needle operating cam for a flat knitting machine for operating needle bodies and sliders of compound needles separately from each other, the needles being mounted in first and second needle beds with ends thereof opposed to each other, characterised in that said needle operating cam comprises raising cam means [24, 30 (Fig. 1); 118 (Figs. 20, 22, 23)] for raising a stitch-delivery needle to a height where stitch transfer can be performed; guide cam means [25 (Fig. 1); 119 (Figs. 20, 22, 23)] for lowering the stitch-delivering needle; and, in relation to a lowering face [26a (Fig. 1); 120e (Fig. 20); 120a (Figs. 22, 23)] of a needle body lowering cam [26 (Fig. 1); 120 (Figs. 20, 22, 23)] of a loop-delivering-side cam, a slider lowering face [29c (Fig. 1); 123c (Figs. 20, 22); 123d (Fig. 23)] is provided for lowering a slider (7; 107) at a time earlier than the lowering face [26a (Fig. 1); 120e (Fig. 20); 120a (Figs. 22, 23)] of said needle body lowering cam [ 26 (Fig. 1); 120 (Figs. 20, 22, 23)] lowers the needle body, so that the formed loop extends between needles in the first and second needle beds. The needle operating cam may include a knitting lock and/or a transfer lock. As the needle operating cam for accomplishing the stitch increasing method of the present invention, other needle operating cams for a flat knitting machine mentioned hereinafter may be used besides the above-mentioned needle operating cam. With the constructions described above, a loop being knitted is caught by the hook of the needle body which is opened as the slider is lowered at a time earlier than the lowering movement of the needle body, and an increased stitch can be knitted. An embodiment of a method of the present invention and needle operating cams for a flat knitting machine for putting the method of the present invention into practice will now be described by way of example and with reference to the accompanying drawings, in which: Figs. 1 to 17 show an apparatus for putting the method of the present invention into practice and a knitted fabric knitted in accordance with the method of the present invention: Fig. 1 shows a cam lock of a carriage as viewed from below; Fig. 2 is a side elevational view showing a needle, a select jack, a selector and a select jack presser placed at positions corresponding to the cam lock; Figs. 3 and 4 are bottom plan views of the cam lock showing the loci of needles on the delivering side and receiving side upon transfer; 1 ○ to 5 ○ of Fig. 5 are side elevational views of needles illustrating a loop delivering procedure upon transfer; Fig. 6 is a plan view of loops produced according to the method of the present invention; Fig. 7 is an illustrative view of loops and needles; Fig. 8a and Fig. 8b are bottom plan views of the cam lock showing the loci of needles on the delivering side and receiving side; 1 ○ to 5 ○ of Fig. 9 are side elevational views of needles illustrating a knitting procedure upon increasing of a stitch; Figs. 10, 12, 14 and 16 are views of textures of knitted fabrics produced in accordance with the present invention; 1 to 8 of Fig. 11, 1 to 8 of Fig. 13, 1 to 8 of Fig. 15 and 1 to 8 of Fig. 17 are illustrative views showing the procedures for knitting the textures shown in Figs. 10, 12, 14 and 16, respectively; Figs. 18 and 19 are plan views illustrating known examples of loop increasing by hand knitting; Fig. 20 is a plan view showing a second embodiment of cam lock of a carriage, as viewed from below; Fig. 21 is a side elevational view of a compound needle; Fig. 22 is a plan view showing a third embodiment of cam lock of a carriage, as viewed from below; Fig. 23 is a plan view showing a fourth embodiment of cam lock of a carriage, as viewed from below; Fig. 24a and Fig. 24b are bottom plan views of the second embodiment cam locks showing the loci of needles on the delivering side and receiving side of the needle operating cam for a flat knitting machine; 1 ○ to 5 ○ of Fig. 25 are side elevational views of needles illustrating a loop delivering procedure upon increasing of a stitch; Fig. 26a and Fig. 26b are bottom plan views of the third embodiment cam locks showing the loci of needles on the delivering side and receiving side of the needle operating cam for a flat knitting machine; and Fig. 27a and Fig. 27b are bottom plan views of the fourth embodiment cam locks showing the loci of needles on the delivering side and receiving side of the needle operating cam for a flat knitting machine. Fig. 1 shows a condition of a cam lock 1 of a carriage as viewed from below. Fig. 2 shows a side elevation of a needle 2, a select jack 3, a selector 4, a select jack presser 5 and so forth placed at positions corresponding to the cam lock 1. The needle 2 used in the arrangement of the present invention is a compound needle. A slider 7 is slidably fitted at an upper portion of an end of a needle body 6 such that a hook 9 of the needle body 6 may be opened or closed by the slider 7 by operating a slider butt 8. Reference numeral 10 denotes a needle butt provided on the needle body 6. A select jack butt 11 has recesses 12, 13 and 14 provided at a base portion thereof such that they may be selectively engaged by a wire 15 extending through a needle bed (not shown) to define a position of the select jack butt 11. When the wire 15 is engaged with recess 12, the select jack butt 11 is positioned at its welt position; when the wire 15 is engaged with recess 13, the select jack butt 11 is positioned at its tuck position; and when the wire 15 is engaged with recess 14, the select jack butt 11 is positioned at its knit position. The select jack presser 5 is a resilient plate member having a channel-shaped side elevation and is engaged at an upper edge thereof by a band plate 16 inserted in and extending through the needle bed (not shown) to press with an end portion thereof against the select jack 3 to urge the select jack butt 11 in the direction to move upwards. Reference numeral 17 denotes a selector butt of the selector 4. The lock 1 is composed of a knitting lock 22 and a transfer lock 23 provided on a cam plate 21. The knitting lock 22 comprises a needle raising cam 24 having a trapezoidal shape with the opposite side inclined faces serving as raising cam faces 24a and 24b, a trapezoidal transfer guide cam 25 disposed on the same centre line as the needle raising cam 24 and having a mountain-shaped concave cam face 25a, a pair of left and right knitting cams 26A and 26B provided for up and down sliding movement in a truncated inverted V-shaped arrangement on the opposite sides of the transfer guide cams 25 and needle raising cam 24, and a lower slider guide cam 27, a middle slider guide cam 28 and an upper slider guide cam 29 provided at three stages above the transfer guide cam 25. The lower slide guide cam 27 has a bow-shaped arcuate face 27a provided at the centre of a lower portion thereof and having the same shape as a bow-shaped arcuate needle butt raising face 24C provided at a top portion of the needle raising cam 24, a slider butt path 27b of a half height contiguous to the bow-shaped arcuate face 27a, a pair of inclined faces 27c at the opposite ends of the slider butt path 27b, and a pair of slider lowering inclined faces 27d. The middle slider guide cam 28 is located above the lower slider guide cam 27 and has a pair of raising inclined faces 28a and a pair of butt paths 28b of a half height disposed in a truncated inverted V-shape at intermediate portions thereof. The upper slider guide cam 29 is located above the middle slider guide cam 28 and has a transfer guide face 29a formed to define a mountain-shaped recessed portion at a mid-portion thereof. The opposite ends of the upper slide guide cam 29 have such a configuration that they cover over the opposite sides of the middle slider guide cam 28 and lower slider guide cam 27 and form a pair of lowering guide faces 29b. The lowering guide faces 29b have a half height, and loop increasing lowering guide faces 29c are provided in parallel to the lowering guide faces 29b. The loop increasing lowering guide faces 29c have the full height. The transfer lock 23 is located adjacent to a trapezoidal top portion of the needle raising cam 24 and has formed thereon a loop-delivering raising cam 30 which has a trapezoidal shape and has a height sufficient to raise the needle 2 to its loop-delivering position, a mountain-shaped cam face 31 formed at the centre of the needle raising cam 24, a loop-receiving needle raising cam 33 of a half height provided for rocking motion into a recessed portion 32 in which it is sunk from the plane of the cam plate 21, and a transfer guide cam 25. Reference numeral 34 denotes a fixed guide cam. Located below the raising cam 24 are a pair of pressers 35A and 35B which act upon the select jack butt 11 at its knit position to sink the butt 10 of the corresponding needle 2 to its half position, a pair of pressers 36A and 36B as well as a presser 37 located between the pressers 36A and 36B which act upon the select jack butt 11 at its tuck position to sink the same, and a presser 38 which acts upon the select jack butt 11 at its welt position and has a greater width than the raising cam 24. The structure of the knitting cams 26 will now be described. The knitting cams 26A and 26B are disposed symmetrically in an opposing relationship to the raising cam faces 24a and 24b of the raising cam 24 for up and down sliding movement on the cam plate 21. In the following, a description will be given of one knitting cam 26B. The knitting cam 26B has a face opposed to the raising cam face 24b of the raising cam 24 which serves as a loop-forming lowering cam face 26a, and a central portion thereof is formed as a recessed portion 41 having a half height, while an inclined face 42 is provided which extends from a portion located a little inwardly of the loop-forming lowering cam face 26a towards the recessed portion 41. Meanwhile, at a lower end portion of the knitting cam 26B contiguous to the lowering cam face 26a, a stepped portion 43 of a height at which the butt at its half position can pass therethrough is formed, such that a needle having a butt of a height to a half position can be lowered only to the stepped portion but another needle having a butt of a height to a full position can be lowered to a lowermost end portion 44, so that a knitted fabric can be produced which has a variation in density. Furthermore, an extension 45 which extends into the recessed portion 41 of the knitting cam 26B is provided on the guide cam 34. The extension 45 has a lowering cam face 45a on one side thereof, and the transfer receiving needle lowering cam face 45a extends parallel to the loop-forming lowering cam face 26a of the knitting cam 26B. Reference numeral 46 denotes a guide cam. Since stitch increasing in the method of the present invention is somewhat coincident with a transfer step, a description will first be given of transfer. GB-A-2193977 describes a cam drive arrangement with symmetrically arranged knitting and transfer cam elements for both carriage and transfer directions. Fig. 3 shows a cam lock 1 for raising and lowering a needle on the side which is to deliver a loop, while Fig. 4 shows another cam lock 1 for raising and lowering a needle on the other side which is to receive a stitch. Selection of the knit, tuck and welt positions of the needles upon transfer is performed by conventional known means. First, raising and lowering movements of a needle on the side which is to deliver a loop will be described with reference to Fig. 3. The pressers 35A and 35B are rocked to their position indicated by solid lines so that they are not engaged with the select jack butts 11 and consequently the needle butts 10 normally keep their full height. Then, the loop-delivering raising cam 30 is positioned at its projected position. Here, if the carriage is moved in the direction indicated by the arrow in Fig. 3, then the needle butt 10 of a needle to deliver a loop moves as indicated by chain-dotted lines at the position I', and consequently it is engaged with the raising cam face 24a of the raising cam 24 and starts its rising motion along the cam face 24a ( 1 ○ and 2 ○ in Fig. 3). Meanwhile, the corresponding slider butt 8 moves as indicated by the line I'' in Fig. 3, and when the slider butt 8 comes almost to a position below the left-hand end of the lower slider guide cam 27, an end of the slider 7 is spaced from the hook 9 due to a difference in the amount of rising between the needle body 6 and the slider 7 to start opening of the hook 9. The hook 9 is opened fully at the position 2 ○ in Fig. 3. While the condition is maintained, the needle butt 10 is raised along the raising cam face 24a of the raising cam 24 until it comes to a base portion of the loop-delivering raising cam 30 ( 3 ○ in Fig. 3), whereafter it is raised along the guide face 30a of the loop-delivering raising cam 30. Meanwhile, the slider butt 8 passes, as the needle body is raised, the raising inclined face 27c of the lower slider guide cam 27 ( 3 ○ in Fig.3) and then passes the portions 28a and 28b of the middle slider cam 28 until it comes to its most raised position, whereafter it moves in a lateral direction. In the meantime, a needle on the loop-receiving side which will be described hereinafter is moved to its most raised position ( 4 ○ in Fig.3) so that it is inserted into a loop carried on the loop-delivering side needle. Subsequently, the needle butt 11 and the slider butt 8 which have moved in a lateral direction are lowered respectively by the lowering guide face 25a of the transfer guide cam 25 and the guide face 29a of the upper slider guide cam 29, but in a portion while the needle butt 10 is lowered along a straight portion of the lowering guide face 25 of the transfer guide cam 25, the slider butt 8 moves in a lateral direction between the middle slider guide 28 and the upper slider guide cam 29, and in that portion the slider is not lowered while only the needle body is lowered so that the hook is closed ( 5 ○ in Fig. 3). The thus closed hook thereafter maintains its closed condition following the motion of the needle body ( 6 ○ and 7 ○ in Fig. 3), and the needle butt is lowered by the lowering cam face 26a of the knitting cam 26B to the lowermost position of the cam 26B ( 8 ○ in Fig. 3), whereafter it is guided by the guide cam 46 ( 9 ○ in Fig. 3). On the other hand, on the loop-receiving side, the pressers 35A, 35B and 37 are rocked to the solid line positions shown in Fig. 4 so that they may not be engaged with a select jack butt 11 for which the II positions is selected. Then, the loop-receiving needle raising cam 33 is positioned at a position rocked in a direction opposite to the advancing direction of the carriage, that is, rocked in the clockwise direction, since it is described that the carriage advances in the direction indicated by the arrow in Fig.4. As the carriage moves in the direction of the arrow in Fig. 4, the select jack butt 11 advances as indicated by chain-dotted lines at the position II and is engaged by the presser 36A ( 1 ○ in Fig. 6). While the select jack butt 11 is held engaged by the presser 36A (between 1 ○ and 2 ○ in Fig. 4), it forces the needle butt 10 and the slider butt 8 to move to their full positions. Since the needle butt 10 having moved at the position II' in Fig. 4 is forced to move to the full position by the presser 36A immediately before it is engaged by the cam face 24a of the needle raising cam 24 ( 1 ○ in Fig. 4), it advances straightforwardly without engaging with the cam face 24a, and after it is released from the presser 36A ( 2 ○ in Fig. 4), it enters the recessed portion 32 from a sinking inclined face 24d of the needle raising cam 24 ( 3 ○ in Fig. 4), whereafter it is engaged, by way of the mountain-shaped cam face 31, by the stitch-receiving needle raising cam 33 and is raised to its most raised position ( 3 ○, 4 ○ and 5 ○ in Fig. 4). Meanwhile, as the needle butt 10 starts its rising movement ( 3 ○ in Fig. 4), the slider begins to open, and it is opened fully at a position immediately before the most raised position of the needle butt 10, whereafter the slider is raised a little together with the needle body (after 5 ○ in Fig. 4) while the needle butt 10 is lowered by the inner side cam face 24e of the needle raising cam 24 and the slider butt is lowered by the lower slider guide cam 27e. However, although the amount of lowering of the needle butt 10 is greater than the amount of lowering of the slider butt, the slider cannot be lowered with respect to the needle body and the hook of the needle remains in an open condition ( 6 ○ in Fig. 4). Then, the needle butt 10 advances straightforwardly and ridges from the recessed portion 32 along the inclined face 24f so that it is spaced away from the needle raising cam 24. However, since the select jack butt 11 undergoes an action of the presser 36B (between 7 ○ and 8 ○ in Fig. 4), it assumes its fully sunk position again and thus jumps the lowering inclined face 26a of the knitting cam 26B without engaging with the same. Then, in the recessed portion 41 of the knitting cam 26B, it is projected again, and consequently it is engaged with the extension 45 of the guide cam 34 ( 9 ○ of Fig. 4) and retracted by the guide face 45a, and consequently the hook is closed. After this, the needle butt advances together with the slider butt while the hook is closed. While the needle on the loop-delivering side and the needle on the loop-receiving side are operated by the separate cam locks on the loop-delivering side and the loop-receiving side respectively, as described above, the conditions of such delivery and reception of a thread are shown in Fig.5. Describing in order, the needle 2F on the loop-delivering side is raised to its most raised position as shown in 1 ○ of Fig. 5 so that a loop L to be transferred is caught by a stepped portion 2a provided on the shank of the needle 2F. In this instance, a spring blade 2b of the needle from which the loop is to be transferred is inserted into the loop L. The position of the needle 2F is the position of 4 ○ shown in Fig. 3. There, the receiving needle 2B is raised into the spring blade 2b to insert the hook thereof into the loop L to be transferred. The position of the needle 2B is 5 ○ shown in Fig, 4. In this instance, the hooks of both of the needles are open. Subsequently, the needle 2F on the loop-delivering side is lowered as seen in 2 ○ of Fig. 5. However, the amount of lowering of the slider is smaller than the amount of lowering of the needle body, and consequently the slider has such a form as to rise with respect to the needle body so that the hook is closed. The position of the needle 2F then is 5 ○ shown in Fig. 3. Then, the needle 2B on the loop-receiving side is lowered a little so that it arrests the loop L with the open hook thereof. The position of the needle 2B then is 6 ○ shown in Fig. 4. The loop-delivering side needle 2F is further lowered relative to the loop-receiving side needle 2B which maintains the position described above for a while so that it is spaced away from the loop L as seen in 3 ○ of Fig. 5. This position is 7 ○ shown in Fig. 3 and 8 ○ shown in Fig. 4. Subsequently, the needle 2B on the loop-receiving side starts its lowering movement as seen in 4 ○ of Fig. 5. The position is 9 ○ shown in Fig. 4. The hook is closed at the position of shown in Fig. 4 at which such lowering movement is completed. Then, the needle 2F on the loop-delivering side is raised with the hook held closed as seen in 5 ○ of Fig. 5 in order to prepare for the subsequent starting of knitting. The position of the needle 2F is 8 ○ shown in Fig. 3. A basic form of loop increasing according to a stitch increasing knitting method of the present invention will now be described. In the case of stitch increasing according to the method of the present invention, such a loop as is shown in Fig. 6 is produced, and several variations are developed based on the loop. In particular, while there are left stitch increasing, right stitch increasing, casting-on stitch increasing and so forth, an example will be described subsequently wherein, when knitting is performed while loops fa, fb, fc, ... are carried on needles FA, FB, FC, ... of one of a pair of needle beds provided in an opposing relationship as shown in Fig. 7, for example on the front side needle bed, the loop fb on the needle FB is increased to make loops fb and fbl. In stitch increasing of the present invention, as is apparent also from Fig. 6, part of the loop fb carried on the needle FB in one of the needle beds provided in the pair is delivered as a new loop fbl to another needle BB in the opposing needle bed. While, in conventional transfer, the loop delivered to the needle BB is removed from the needle FB on which the loop has been carried, according to the method of the present invention the loop on the needle FB is partially delivered to the opposing needle BB without being removed from the needle FB. Delivery and reception of a loop will now be described with reference to cam locks shown in Fig. 8a and Fig. 8b. This is an example wherein a stitch is increased from the cam lock shown at an upper portion in Fig. 8 to the other cam lock shown at a lower portion in Fig. 8. In the example described above, the side which is to deliver a loop therefrom will hereinafter be referred to as the delivering side, while the side which is to receive such a loop will hereinafter be referred to as the receiving side. The cam lock shown in Fig. 8a is the delivering side and the other cam lock shown in Fig. 8b is the receiving side. On the receiving side, the pressers 36A and 36B, loop-delivering raising cam 30 and so forth assume the same positions as those upon transfer. On the delivering side, the trailing side presser 36a and loop-delivering raising cam 30 are positioned to respective operative positions, while the leading side presser 36b is positioned to its inoperative position. The carriage advances in the direction indicated by an arrow, and select jack butts 11, needle butts 10 and slider butts 8 follow the courses indicated by chain-dotted lines II, II' and II'' respectively. First, the body of the needle FB on the delivering side having the loop fb thereon is raised by the course of II'. In this instance, since the amount of rising of the slider butt 8 is smaller than the amount of rising of the needle butt 10, the slider lowers and the hook is opened as the needle body is raised. Consequently, the loop fb carried in the hook slips in the hook and is arrested by a stepped portion 60 of the needle FB. Thereupon, the needle BB on the receiving side opposed to the needle FB is raised by the loop-receiving needle raising cam 33 in the same way as upon transfer so that the hook 9 is inserted into a blade 61 of the needle FB, thereby to insert the hook 9 into the loop fb (the position of 1 shown in Fig. 8 and 1 of Fig. 9). Subsequently, the needle FB on the delivering side is lowered by the transfer guide cam 25, but since the slider passes between the middle slider guide 28 and the upper slider guide 29, the amount of lowering thereof is small and consequently the slider 7 of the needle FB is put into a closing condition with respect to the hook 9 and part of the loop fb is caught by the hook 9 of the needle BB on the receiving side (the position of 2 shown in Fig. 8 and 2 of Fig. 9). By succeeding movement of the carriage, the select jack butt 11 of the needle FB on the delivering side is engaged by and sunk by the presser 36A. Consequently, the needle butt 10 is pushed into the needle trick and thus jumps the cam face of the knitting cam 26A and enters the recessed portion 41, and then it is engaged by the lowering cam face 45a of the extension 45 of the guide cam 34. Since the slider butt 8 is also sunk then, it is not engaged by the lowering cam face 29b of the upper slider guide cam 29, and as the select jack butt 11 is disengaged from the presser 36A and the slider butt 8 comes out of the needle trick and is thus engaged with the lowering cam face 29c, the slider is lowered and the hook is opened, and the loop fb is arrested by the hook 9 of the needle FB (the position of 3 ○ shown in Fig. 8 and 3 ○ of Fig. 9), whereafter both of the needles FB and BB are lowered further. As a result, the loop fb, which is not carried, in normal transfer, on the needle FB at this position, remains carried on the hook of the needle FB (the position of 4 ○ shown in Fig. 8 and 4 ○ of Fig. 9). Then, as both of the needles FB and BB are further lowered, the loop fb carried on the hooks of both of the needles makes loops fb and fbl (the position of 5 ○ shown in Fig. 8 and 5 ○ of Fig. 9). As a first example of an application of the description above, knitting for left-hand loop increasing of a texture as shown in Fig. 10 will be described. A knitting process of the texture is shown in Fig. 11. A back bed having needles BA, BB, BC, ... thereon is provided for a front head having needles FA, FB, FC, ... thereon, and left loop increasing is performed for a knitted fabric carried on the needles FA, FB, ... of the front bed. Loops fa, fb, ... are carried on the needles FA, FB, ... of the front bed (1 of Fig. 11). Thus, it is intended to increase a new loop fal between the loops fb and fc, and first the loops fc, fd, ... are moved to the right by one loop distance to the condition shown in 4 of Fig. 11. The means is such that the loops fc, fd, ... on the needles FC, FD, ... of the front bed are first transferred to the needles BC, BD, ... of the back bed (2 of Fig. 11) and then the back bed is racked to the right by one pitch (3 of Fig. 11), and then at that position the loops fc and fd carried on the needles BC, BD of the back bed are transferred to the needles FD and FE of the front bed. The needle FC which does not have a loop thereon is made between the needles FB and FD of the front bed in this manner (4 of Fig. 11). Subsequently, the loop fb carried on the needle FB of the front bed is divided into two, and part of the loop fb is arrested by the needle BA of the back bed at a position opposed to the needle FB of the front bed on which the loop fb is carried, thereby to make a loop fbl (5 of Fig. 11). The means is the same as the means described hereinabove with reference to Fig. 9, and the shape of the loop which is carried on the needle FB of the front bed and the needle BA of the back bed has the same basic shape as that shown in Fig. 6. If the back bed is racked to the right by one pitch in this condition, the condition shown in 6 of Fig. 11 is obtained. Then, the loop fbl carried on the needle BA of the back bed is transferred to the needle FC of the front bed on which no loop is carried, thereby to obtain such a condition as is shown in 7 of Fig. 11. If knitting of a course is performed with the needles FA, FC, FD and FE, then such a condition as is shown in 8 of Fig. 11 is obtained. After that, knitting is performed with all of the needles FA, FB, FC, ... As a modification to the example of application described above, the example shown in Fig. 12 is such that the direction of racking is reversed as compared with that in the first example so that knitting can be performed for all wales immediately after the increasing of a loop. Knitting steps are illustrated in order in Fig. 13. In the case of the present example, different from the condition shown in 5 of Fig. 11 wherein a loop is carried between the needle FB on the left-hand side of the needle FC which does not have a loop thereon and the opposing needle BA, a loop is carried between the needles FD and BC on the right-hand sides of the needles FC and BB which have no loop thereon as seen in 5 of Fig. 13. Then, the back bed is racked to the left by one pitch and a loop of the needle BC is transferred to the needle FC as seen in 6 and 7 of Fig. 13. Consequently, the loop carried on the needles FC and FD is closed in the present example while the loop carried on the needles FB and FC shown in 8 of Fig. 11 in the example described hereinabove remains open. Accordingly, when knitting for a next course is to be performed from the condition shown in 7 of Fig. 13, knitting can be performed immediately using all of the needles. An example which makes use of casting-on loop increasing of three loops as shown in Fig. 14 will now be described as a second example of application. While such knitting steps are illustrated in Fig. 15, the steps up to the step shown in 5 of Fig. 15 are the same as those shown in Fig. 11. In 6 of Fig. 15, the back bed is racked to the right by one pitch to oppose the needle BA to the needle FC. Then, a loop fbl of the needle BA is transferred to the needle FC (7 in Fig. 14). Subsequently, the back bed is racked to the left by a half pitch to position the needle BA in an opposing relationship between the needles FB and FC. Then, a thread is supplied to the needle BA and all of the needles FA, FB, ... on the front bed side, and then the needles are lowered. Consequently, the condition as shown in 8 of Fig. 15 is obtained. The front bed is racked to the left by a half pitch from this condition, and then loops of the needles FA and FB on the front bed are transferred to needles BY and BZ on the back bed, whereafter the back bed is racked to the left by one pitch and then the loops of the needles BY, BZ and BA of the back bed are transferred to the needles FZ, FA and FB of the front bed (9 of Fig. 15). Also, in the example shown in Fig. 16, knitting is performed in such an order as is illustrated in Fig. 17 with casting-on loop increasing of three loops. By such knitting, three casting-on increased loops are made, and by making use of such loop increasing for a case wherein a knitting width is to be increased in fashioning or the like, one can perform fashioned knitting on an automatic knitting machine. Furthermore, as an example of the production of a pattern, a pattern which makes use of loop increasing such as for example an Aran pattern, can be knitted on an automatic machine. As described in detail so far, according to a method of the present invention, among compound needles inserted in needle grooves of first and second needle beds disposed with the ends thereof opposed to each other, that needle in either one of the first and second needle beds which has a loop carried thereon is raised to a transfer position, and then another needle in the opposing needle bed is raised until it is inserted into the loop carried on the former needle, whereafter the two needles are lowered to cause the knitted fabric loop to be caught by the hook of the latter needle, and then, when the needle which has been lifted to the transfer position is lowered, the loop carried on the needle being lowered is caught again in the hook of the needle being lowered so that the loop extends between the needles in the first and second needle beds. Accordingly, stitch increasing which is possible by hand knitting but has been considered impossible with an automatic flat knitting machine is made possible. Further, by developing the basic form of such stitch increasing, it can be utilised for the case wherein a knitting width is to be increased by left stitch increasing, right stitch increasing, casting-on stitch increasing or the like as in fashioned knitting, and knitting on an automatic knitting machine is further facilitated. Also, in the production of a pattern, it is possible to knit, on an automatic machine, a pattern which makes use of stitch increasing such as for example an Aran pattern. According to the invention, a needle operating cam for a flat knitting machine which has a loop knitting cam and a loop transfer cam for operating needle bodies and sliders of compound needles separately from each other, is constituted such that, for a lowering face of a needle body lowering cam of a loop-delivering side cam of the loop transfer cam, a slider lowering face for lowering a slider at a time earlier than that by the lowering face of the needle body lowering cam is provided. Accordingly, it is possible to perform transfer and stitch increasing with the same lock, and thus an operation which is conventionally performed in two separate operations requires only one operation and consequently the knitting efficiency can be improved. Other embodiments according to the present invention will now be described. A second embodiment relates to a needle operating cam having a lock for stitch increasing. A third embodiment relates to one having a knitting lock and a lock for stitch increasing. A fourth embodiment relates to one having a transfer lock and a lock for stitch increasing. Fig. 20 shows a condition of a cam lock 1 of a carriage of the second embodiment according to the present invention as viewed from below. Fig. 21 shows a side elevation of a needle 102, a select jack 103, a selector 104, a select jack presser 105 and so forth. The needle 102 used in a flat knitting machine equipped with a needle operating cam according to the present invention is a compound needle, and a slider 107 is slidably fitted at an upper portion of an end of a needle body 106 such that a hook 109 of the needle body 106 may be opened or closed by the slider 107 by operating a slider butt 108. Reference numeral 110 denotes a needle butt provided on the needle body 106. A select jack butt 111 has recesses 112, 113 and 114 provided at a base portion thereof such that they may be selectively engaged by a wire 115 extending through a needle bed (not shown) to define a position of the select jack butt 111. When the wire 115 is engaged with recess 112, the select jack butt 111 is positioned at its welt position; when the wire 115 is engaged with recess 113, the select jack butt 111 is positioned at its tuck position; and when the wire 115 is engaged with recess 114, the select jack butt 111 is positioned at its knit position. The select jack presser 105 is a resilient plate member having a channel-shaped side elevation and is engaged at an upper edge thereof by a band plate 116 inserted in and extending through the needle bed (not shown) to press at an end portion thereof against the select jack 103 to urge the select jack butt 111 in a direction to move upwards. Reference numeral 117 denotes a selector butt of the selector 104. In the following, a description will first be given of the constructions of the second embodiment, third embodiment and fourth embodiment of a needle operating cam for a flat knitting machine according to the present invention. It is to be noted that although the needle operating cams for a flat knitting machine shown in the second embodiment and third embodiment (refer to Figs. 20 and 22) do not have a transfer function, the word "transfer" will be used for convenience in the following description. Furthermore, although the needle operating cams shown in the second embodiment and fourth embodiment (refer to Figs. 20 and 23) do not have a knitting function, the words "knot position, tuck position" will be used for convenience in the following description. Furthermore, although the needle operating cams for a flat knitting machine of the individual embodiments have different constructions and functions, the same words and reference numerals are used for the respective same components. Thus, the needle operating cam for a flat knitting machine of the second embodiment according to the present invention shown in Fig. 20 described above is provided for the exclusive use for the knitting of an increased loop. A cam lock 101 provided on a cam plate 140 includes a needle raising cam 118 having a trapezoidal shape with the opposite side inclined faces serving as raising cam faces 118a and 118b, a trapezoidal guide cam 119 disposed on the same centre line as the needle raising cam 118 and having a mountain-shaped concave cam face 119a, a pair of fixed guide cams 120A and 120B provided on the opposite sides of the guide cam 119 and needle raising cam 118, and a middle guide cam 121, a pair of slider guide cams 122a and 122b and an upper slide guide cam 123 provided above the guide cam 119. Each of the fixed guide cams 120A and 120B has a lowering guide face portion 120a on the inner side of a lower portion thereof, and the lowering guide face portions 120a and 120b have a half height of a parallelogram shape while guide faces of the lowering guide faces 120a and 120b for a needle butt 110 each comprise an upper horizontal guide face 120c and a pair of inclined guide faces 120d and 120e. The middle guide cam 121 is located above the guide cam 119 and has a substantially triangular shape, and the slider guide cams 122a and 122b are provided on the opposite sides of the middle guide cam 121. An inclined face 122c for guiding a slider butt 108 is formed at each of portions of the middle guide cam 121 which are engaged by the slider guide cams 122a and 122b. The upper slider guide cam 123 is located above the slider guide cams 122a and 122b and the middle guide cam 121 and has a guide face 123a formed to define a mountain-shaped recessed portion at a mid-portion thereof. The opposite ends of the upper slider guide cam 123 have such a configuration that they cover over the opposite sides of the middle guide cam 121 and slider guide cams 122a and 122b such that a pair of loop-increasing lowering guide faces 123c are provided thereon. The loop-increasing lowering guide faces 123c have a full height. Located below the needle raising cam 118 are a pair of pressers 124A and 124B which act upon the select jack butt 111 at its tuck position to sink the same, and another presser 125 which acts upon the select jack butt 111 at its welt position and has a greater width than the needle raising cam 118. Reference numeral 126 denotes a guide cam. The needle operating cam for a flat knitting machine of the third embodiment according to the present invention shown in Fig. 22 has both a knitting function and a stitch increasing knitting function. A cam lock 122 provided on a cam plate 140 includes a needle raising cam 118 having a trapezoidal shape with the opposite side inclined faces serving as raising cam faces 118a and 118b, a trapezoidal transfer guide cam 119 disposed on the same centre line as the needle raising cam 118 and having a mountain-shaped concave cam face 119a, a pair of left and right knitting cams 120A and 120B provided for up and down sliding movement in a truncated inverted V-shaped arrangement on the opposite sides of the transfer guide cam 119 and needle raising cam 118, and a lower slider guide cam 122, a middle slider guide cam 121 and an upper slider guide cam 123 provided at three stages above the transfer guide cam 119. The lower slide guide cam 122 has a bow-shaped arcuate face 122a provided at the centre of a lower portion thereof and having the same shape as a bow-shaped arcuate needle butt raising face 118c provided at a top portion of the needle raising cam 118, a slider butt path 122b of a half height contiguous with the bow-shaped arcuate face 122a, a pair of inclined faces 122c at the opposite ends of the slider butt path 122b, and a pair of slider lowering inclined faces 122d. The middle guide cam 121 is located above the lower slider guide cam 122. The upper slider guide cam 123 is located above the middle guide cam 121 and has a guide face 123a formed to define a mountain-shaped recessed portion at a mid-portion thereof. The opposite ends of the upper slider guide cam 123 have such a configuration that they cover over the opposite sides of the middle guide cam 121 and lower slider guide cam 122 such that a pair of lowering guide faces 123b are provided thereon. The lowering guide faces 123b have a half height, and loop-increasing lowering guide faces 123c are provided in parallel with the lowering guide faces 123b. The loop-increasing lowering guide faces 123c have a full height. Meanwhile, located below the needle raising cam 118 are a pair of pressers 128A and 128B which act upon the selector jack butt 111 at its knit position to sink the butt 110 of the corresponding needle 102 to its half position, a pair of pressers 124A and 124B which act upon the select jack butt 111 at its tuck position to sink the same, and a presser 125 which acts upon the select jack butt 111 at its welt position and has a greater width than the raising cam 118. The knitting cams 120A and 120B are supported symmetrically in an opposing relationship to the raising cam faces 118a and 118b of the raising cam 118 so that they may be slidably moved upwards and downwards on the cam plate 140. In the following, a description will be given of the knitting cam 120B. The knitting cam 120B has a face opposed to the raising cam face 118b of the raising cam 118 which serves as a loop-forming lowering cam face 120a, and a central portion thereof is formed as a recessed portion 129 having a half height while an inclined face 130 is present which extends from a portion located a little inwardly of the loop-forming lowering cam face 120a towards the recessed portion 129. Meanwhile, at a lower end portion of the knitting cam 120B contiguous with the lowering cam face 120a, a stepped portion 131 of a height which the butt at its half position can pass therethrough is formed such that a needle having a butt of a height to a half position can be lowered only to the stepped portion 131 but another needle having a butt of a height to a full position can be lowered to a lowermost end portion 132 so that a knitted fabric can be produced which has a variation in density. Furthermore, an extension 133 which extends into the recessed portion 129 of the knitting cam 120B is provided on the guide cam 134. The extension 133 has a lowering cam face 133a on one side thereof, and the transfer receiving needle lowering cam face 133a extends parallel to the loop-forming lowering cam face 120a of the knitting cam 120B. Reference numeral 135 denotes a guide cam. The needle operating cam for a flat knitting machine of the fourth embodiment according to the present invention shown in Fig. 23 can perform transfer and knitting of an increased loop simultaneously. A cam lock 101 provided on a cam plate 140 includes a needle raising cam 118 having a trapezoidal shape with the opposite side inclined faces serving as raising cam faces 118a and 118b, a trapezoidal guide cam 119 disposed on the same centre line as the needle raising cam 118 and having a mountain-shaped concave cam face 119a, a pair of fixed guide cams 120A and 120B provided on the opposite sides of the guide cam 119 and needle raising cam 118, and a middle guide cam 121, a pair of slider guide cams 122a and 122b and an upper slider guide cam 123 provided above the guide cam 119. Meanwhile, a transfer lock 123 includes a cam face 138 formed in a mountain-shape at the centre of the needle raising cam 118, and a transfer guide cam 119. Each of the fixed guide cams 120A and 120B has a lowering guide face 120a on the inner side of a lower portion thereof, and the lowering guide face 120b has a half height of parallelogram shape while a guide face of the lowering guide face 120a for a needle butt 110 is composed of an upper horizontal guide face 120c and an inclined guide face 120e. The middle guide cam 121 is located above the guide cam 119 and has a substantially triangular shape. The slider guide cams 122a and 122b are provided on the opposite sides of the middle guide cam 121. An inclined face 122c for guiding a slider butt is formed at each of portions of the middle guide cam 121 which are engaged by the slider guide cams 122a and 122b. The upper slider guide cam 123 is located above the slider guide cams 122a and 122b and middle guide cam 121 and has a guide face 123a formed to define a mountain-shaped recessed portion at a mid-portion thereof. The opposite ends of the upper slider guide cam 123 have such a configuration that they cover over the opposite sides of the middle guide cam 121 and lower slider guide cams 122 such that a pair of loop-increasing lowering guide face portions 123b are provided on the inner sides of lower portions thereof. The loop-increasing lowering guide face portions 123b have a half height of parallelogram shape and each has a lowering guide face 123c and a loop-increasing guide face 123d for guiding the slider butt 108. The loop-increasing guide face 123d is composed of an upper horizontal guide face portion 123e and an inclined guide face portion 120f. Located below the needle raising cam 118 are a pair of pressers 124A and 124B which act upon the select jack butt 111 and its tuck position to sink the same, and another presser 125 which acts upon the select jack butt 111 at its welt position and has a greater width than the needle raising cam 118. Reference numeral 135 denotes a guide cam. The operation of the needle operating cams for a flat knitting machine described above will now be described, based on the third embodiment of needle operating cam for a flat knitting machine. In Figs. 24a and 24b, an example is shown wherein a stitch is increased from the cam lock shown in the upper portion to the other cam lock shown in the lower portion. The cam lock shown in Fig. 24a will hereinafter be referred to as the delivering side, while the cam lock shown in Fig. 24b will hereinafter be referred to as the receiving side. On the receiving side, the pressers 124A and 124B, loop-delivering raising cam 137 and so forth assume the same positions as those upon transfer. On the delivering side, the trailing side presser 124A and loop-delivering raising cam 137 are positioned at respective operative positions while the leading side presser 124b is positioned at its inoperative position. The carriage advances in the direction indicated by the arrow, and select jack butts 111, needle butts 110 and slider butts 108 follow the courses of chain-dotted lines indicated at II, II' and II'' respectively. First, the body of the needle FB on the delivering side having the loop fb thereon is raised by the course of II'. In this instance, since the amount of rising of the slider butt 108 is smaller than the amount of rising of the needle butt 110, the slider lowers and the hook is opened as the needle body is raised. Consequently, the loop fb carried in the hook slips in the hook and is arrested by a stepped portion 160 of the needle FB. Thereupon, the needle BB on the receiving side opposing the needle FB is raised by the loop-receiving needle raising cam 133 in the same way as upon transfer, so that the hook 109 thereof is inserted into a blade 161 of the needle FB, thereby to insert the hook 109 into the loop fb (the position 1 shown in Fig. 24 and 1 in Fig. 25). Subsequently, the needle FB on the delivering side is lowered by the guide cam 119 while the slider 107 is lowered along guide face 123a of the upper slide guide cam 123. Even in the condition in which lowering movement of the slider 107 is stopped, the needle FB continues to be lowered and the hook 109 keeps its open condition. By lowering movement of the needle FB and slider 107 as described above, the loop fb will slip down into the hook 109 (the position 2 ○ shown in Fig. 24 and 2 ○ in Fig. 25). By succeeding movement of the carriage, the select jack butt 111 of the needle FB on the delivering side is engaged by and sunk by the presser 124A. Consequently, the needle butt 110 is pushed into the needle trick and thus jumps the cam face 120a of the knitting cam 120A and enters the recessed portion 129. It is then engaged by the lowering cam face 133a of the extension 133 of the guide cam 134. Since the slider butt 108 is also sunk then, it is not engaged by the lowering cam face 123b of the upper slider guide cam 123, and as the select jack butt 111 is disengaged from the presser 124A and the slider butt 108 comes out of the needle groove and is thus engaged by the lowering cam face 123C, the slider is lowered and the hook is opened, and the loop fb is caught by the hook 109 of the needle FB (the position 3 ○ shown in Fig. 24 and 3 ○ in Fig. 26), whereafter both the needles FB and BB are lowered further. As a result, the loop fb, which is not carried, in normal transfer, on the needle FB at this position, remains carried on the hook of the needle FB (the position 4 ○ shown in Fig. 24 and 4 ○ in Fig. 25). Then, as both of the needles FB and BB are further lowered, the loop fb carried on the hooks of both of the needles makes loops fb and fbl (the position 5 ○ shown in Fig. 24 and 5 ○ in Fig. 25). Consequently, an increased stitch is made, and such increased stitch can be utilised in the case where a knitting width is to be increased as in fashioned knitting or the like. In Figs. 26a and 26b, the courses II, II' and II" followed by the select jack butt 111, needle butt 110 and slider butt 108 of the needle operating cam for a flat knitting machine of the second embodiment described above are indicated by chain-dotted lines. While the construction of the cam locks of the present embodiment is different from the construction of the cam locks of the third embodiment described above, the actions to perform knitting of an increased stitch when the select jack butt 111, needle butt 110 and slider butt 108 follow the paths indicated by the chain-dotted lines in the Figures are similar to the actions in the third embodiment described above. Meanwhile, in Fig. 27a and 27b, the courses II, II' and II'' followed by the select jack butt 111, needle butt 110 and slider butt 108 of the needle operating cam for a flat knitting machine of the fourth embodiment described above are indicated by chain-dotted lines. Although the construction of the cam locks of the present embodiment is also different from the construction of the cam locks of the third embodiment described above, the actions to perform knitting of an increased loop when the select jack butt 111, needle butt 110 and slider butt 108 follow the paths indicated by the chain-dotted lines in the Figures are similar to the actions in the third embodiment described above. As described so far, a needle operating cam for a flat knitting machine for operating needle bodies and sliders of compound needles separately from each other is constructed such that, for a lowering face of a needle body lowering cam of a loop-delivering side cam, a slider lowering face for lowering a slider at a time earlier than that by the lowering face of the needle body lowering cam is provided. Accordingly, knitting of an increased stitch which can conventionally be performed only by hand knitting can be performed automatically on the flat knitting machine. The needle operating cam may be provided on a carriage independently as a needle operating cam for a flat knitting machine for exclusive use for the stitch increasing. Alternatively, a needle operating cam for a flat knitting machine which has a knitting lock and operates for needle bodies and sliders of compound needles separately from each other is constructed such that, for a lowering face of a needle body lowering can of a loop-delivery side cam, a slider lowering face for lowering a slider at a time earlier than that by the lowering face of the needle body lowering cam is provided. Accordingly, knitting and stitch increasing can be performed with the needle operating cam for a flat knitting machine. Further, a needle operating cam for a flat knitting machine which has a transfer lock and operates needle bodies and sliders of compound needles separately from each other is constructed such that, for a lowering face of a needle body lowering cam of a loop-delivering side cam, a slider lowering face for lowering a slider at a time earlier than that by the lowering face of the needle body lowering cam is provided. Accordingly, transfer and stitch increasing can be performed simultaneously with this needle operating cam for a flat knitting machine. Furthermore, various knitting operations can be performed simultaneously by the provision of the needle operating cams for a flat knitting machine described above in combination on a carriage.

Claims: A method of stitch increasing characterised in that, among compound needles (FB, BB) inserted in needle grooves of first and second needle beds disposed with ends thereof opposed to each other, that needle (FB) in either one of said first and second needle beds which has a loop (fb) carried thereon is raised to a transfer position, and then another needle (BB) in the opposing needle bed is raised until it is inserted into the loop (fb) carried on the former needle (FB), whereafter the two needles (FB, BB) are lowered to cause the knitted fabric loop (fb) to be caught by the hook (9; 109) of the latter needle (BB), and that when the needle (FB) which has been lifted to the transfer position is lowered, the loop (fb) carried on the needle (FB) being lowered is caught again in the hook (9; 109) of the needle (FB) being lowered so that the loop (fb,fb 1 ) extends between the needles (FB, BB) in said first and second needle beds. A needle operating cam for a flat knitting machine for operating needle bodies (6; 106) and sliders (7; 107) of compound needles (2; 102) separately from each other, the needles being mounted in first and second needle beds with ends thereof opposed to each other, characterised in that said needle operating cam comprises raising cam means [24, 30 (Fig. 1); 118 (Figs. 20, 22, 23)] for raising a stitch-delivery needle to a height where stitch transfer can be performed; guide cam means [25 (Fig. 1); 119 (Figs. 20, 22, 23)] for lowering the stitchdelivering needle; and, in relation to a lowering face [26a (Fig. 1); 120e (Fig. 20); 120a (Figs. 22, 23)] of a needle body lowering cam [26 (Fig. 1); 120 (Figs. 20, 22, 23)] of a loop-delivering-side cam, a slider lowering face [29c (Fig. 1); 123c (Figs. 20, 22); 123d (Fig. 23)] is provided for lowering a slider (7; 107) at a time earlier than the lowering face [26a (Fig. 1); 120e (Fig. 20); 120a (Figs. 22, 23)] of said needle body lowering cam [ 26 (Fig. 1); 120 (Figs. 20, 22, 23)] lowers the needle body, so that the formed loop extends between needles in the first and second needle beds. A needle operating cam according to claim 2, which includes a knitting lock (22). A needle operating cam according to claim 2, which includes a transfer lock (23). A needle operating cam according to claim 2, which includes a knitting lock (22) and a transfer lock (23).

Inventors: MIYAMOTO MASAKI, SHIMA MASAHIRO, MIYAMOTO, MASAKI, SHIMA, MASAHIRO
Applicants: SHIMA SEIKI MFG, SHIMA SEIKI MFG., LTD.
Application year: 1991
Main classification: D04B7
IPC codes: D04B7