Knitted fabric presser of flat knitting machine

Abstract: A knitted fabric presser are provided with pressers corresponding to respective reciprocal directions and installed in a carriage as one unit to be switchable. A first presser (1) presses a knitted fabric when the carriage is being moved in the left direction to knit. A second presser (2) is waiting in a resting position. The first presser (1) moves in conjunction with displacement of a sliding plate (14) for driving in one direction on which provided with a follower (16) engaged with a grooved cam (4) for driving in one direction. Similarly, the second presser (2) moves in conjunction with displacement of a sliding plate (15) for driving in the other direction on which provided with a follower (17). Displacement of a grooved cam plate (3) is caused by driving via a rack engaged with a pinion (32) fixed at a rotation axis of a motor (30). Movement traces of the first pressure (1) and the second presser (2) are determined so that the both pressers (1, 2) are prevented from interfering with each other on movement thereof between a pressing position and a resting position.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knitted fabric presser of flat knitting machine, particularly to such one which is installed at a carriage unit to be movable between a pressing position where the presser is operative and a resting position where the presser is inoperative. 2. Description of the Related Art Conventionally, a knitted fabric presser as shown in Fig. 20 is used at each lock of a carriage unit in a flat knitting machine, especially, V bed type one. The knitted fabric presser is also called stitch presser. A L-shaped presser 101, by a horizontal portion thereof, presses a knitted fabric 102 from above. In a flat knitting machine of V bed type, a front needle bed 103 and a rear needle bed 104 are arranged opposite to each other in a reversed V-shape. Press functioning of the presser 101 is conducted at a gap 105 formed between the front needle bed 103 and the rear needle bed 104 of the flat knitting machine of V bed type. When knitting needles 106, 107 ascend for knitting or transferring, by pressing the knitted fabric 102 inside the gap 105, uppermost loops 108, 109 of the knitted fabric 102 are prevented from froating. When pressing by the stitch presser is not needed, the presser 101 is made apart from the gap 105 by moving the presser 101 without touching sinkers 110, 111. The presser 101, which is generally shaped like L-letter, presses the knitted fabric 102 by the horizontal portion thereof extending along a movement direction of the carriage. A vertical portion of the presser 101 to the movement direction of the carriage is attached to a mechanism which makes the presser 101 move in conjunction with the carriage. A yarn for knitting the fabric 102 is fed to points of the knitting needles 106, 107 almost in the middle of the horizontal portion of the presser 101. The vertical portion of the presser 101 must be placed upstream of a knitting direction in order to set apart the presser 101 from the loops 108, 109 formed by knitting action of the knitting needles 106, 107. Therefore, both of pressers 101 for forth and back movements of reciprocal knitting action are needed in order to reciprocally knit in relation to longitudinal directions of the needle beds 103, 104. A sufficient length of the horizontal portion of the presser 101 is required in order to satisfactorily press the knitted fabric 102. Though it is possible to turn the direction of the horizontal portion on the assumption that the vertical portion is a rotation axis, that requires a unpractical large space. It is a practical constitution that dedicated pressers 101 for corresponding to forth and back movements are installed and a presser 101 to be actuated is switched according to the movement direction. There are schematically two types in manner to install a stitch presser as shown in Fig. 20. One is a type to install a stitch presser on upper portion of a cam box of the carriage crossing over the front and rear needle beds. The other is a type to install a stitch presser on a yarn guide rail provided just above a gap along a longitudinal direction of the needle bed. The prior art regarding the type to install on the upper portion of a cam box is disclosed, for example, in the Japanese Examined Patent Publication JP(B2) 62-15662 and JP(B2) 3-66415 by the present applicant. According to the prior art disclosed in JP(B2) 62-15662, a presser for forth movement is installed on upper portion of one cam box, and one for back movement is installed on the other cam box. At the upper parts of both pressers are provided pins which are engaged with grooved cams. When the grooved cam reaches receiving pieces fixed on both longitudinal ends of the needle bed, the presser is switched to be operative or inoperative. Further, according to the prior art disclosed in JP(B2) 3-66415, function or non-function of the presser is switched by using a stepping motor and a swing arm. Such type of prior art wherein a stitch presser is installed on a yarn guide rail is disclosed, for example, in the Japanese Unexamined Patent Publication JPA 58-46156. According to the prior art disclosed in JPA 58-46156, a stitch presser moving together with a carriage is installed on a yarn guide rail just above a gap and a direction of the presser is changed by receiving pieces provided on both ends of a needle bed. Because a lot of yarn feeders are required to run in a flat knitting machine, employing such a type of stitch presser installed on a yarn guide rail causes decrease of the number of yarn feeders capable of running. In the prior art such as disclosed in JP(B2) 62-15662 and JP(B2) 3-66415, the number of yarn feeders running on a yarn guide rail does not decrease because a stitch presser is installed on a carriage, which is different from the prior art as disclosed in JP(B2) 58-46156. According to the prior art disclosed in JP(B2) 62-15662 and JPA 58-46156, the direction of presser can not be changed unless a carriage reaches either of the longitudinal ends of needle bed. In the prior art disclosed in JP(B2) 3-66415, since function or non-function of a presser is switched by driving a stepping motor, it is possible to conduct switching at any position regarding the longitudinal direction of needle bed. In certain cases of flat knitting machine, it is unnecessary to use the entire longitudinal width of needle bed for knitting. In these cases, if a presser does not need to be switched, it is possible to knit quickly by reciprocally moving a carriage only in a region where a knitted fabric is formed. If it is necessary to move the carriage to a longitudinal end of a needle bed in order to switch a presser, knitting time cannot be reduced no matter how narrow width of knitted fabric may be. According to the prior art disclosed in JP(B2) 3-66415, function or non-function of a presser can be switched at any longitudinal position of a needle bed by a unit including a stepping motor and a swing arm. That, however, causes a large-sized carriage or limitation of place for installation because respective units are needed for forth and back movements. On the other hand, according to the prior art disclosed in JP(B2) 62-15662 and JP(B2) 3-66415, respective pressers for forth and back movements should be arranged separately on carriages for front and rear needle beds. This is because the respective pressers interfere with each other in case they are arranged on the same carriage. More specifically, it is easy to prevent the pressers from interfering with each other when one presser is placed in pressing position and the other presser in resting position. However, when both pressers are in resting position or when the positions thereof are on the route to be mutually converted, there is a high likelihood that they interfere with each other because of overlapping of the movement traces. In case the horizontal portion of the presser is decreased in length, the probability of interference can be reduced, to be sure, however a knitted fabric can not be pressed satisfactorily by a presser with a shorter length of horizontal portion. The preamble of claim 1 is known from US-A-3,685,317. It is remarked that both GB-A-2,097,431 and US-A-3,685,317 disclose a presser assembly for a flat knitting machine, comprising a carriage, a first presser, a second presser and means for moving the first and second pressers. However, the specific single unit provided on the carriage according to the present invention has not been disclosed, since the known presser assemblies are consistently mounted for split operation according to the direction of stroke of the carriage on both carriages for the needle beds respectively. SUMMARY OF THE INVENTION It is an object of the invention to provide a knitted fabric presser of V-bed type flat knitting machine which is installed as one unit at a carriage for one of needle beds and be able to be switched easily for both of reciprocal directions. The invention therefore provides a knitted fabric presser assembly for a flat knitting machine, installed on a carriage movable in opposite longitudinal directions of needle beds of the said flat knitting machine and comprising: a first presser for pressing knitted fabric upon movement of the said carriage in one of said longitudinal directions; a second presser for pressing knitted fabric upon movement of the said carriage in the other of said longitudinal directions; and means for moving the first and second pressers, to cause one of the first or second pressers to move to the respective pressing position thereof and to cause the other of said first or second pressers to be prevented from interfering with each other during movement thereof, wherein first and second rest positions for the pressers are provided at different distances from the pressing position by first and second back and forth movement assemblies connected to driving means, characterized in that the knitted fabric presser assembly is installed as a single unit on said carriage for pressing fabric knitted by the knitting machine, wherein the said first and second pressers are installed on the same carriage, the presser unit being installed at a carriage for one needle bed. Advantageously, the means for moving the first and second pressers comprise a grooved cam plate being capable of reciprocal movement relative to the carriage and being provided with a grooved cam for driving in one direction of the reciprocal movement and with a grooved cam for driving in the other direction of the reciprocal movement formed respectively thereon; means for driving the grooved cam plate relative to the carriage; first back and forth movement means, having a follower engaged with the one direction driving grooved cam formed on the grooved cam plate, for guiding the first presser from a pressing prosition to a first resting position where the knitted fabric is not pressed in conjunction with displacement of the follower on movement of the grooved cam plate in the one direction relative to the carriage, and for guiding the second presser from the first resting position to the pressing position in conjuntion with displacement of the follower on movement of the grooved cam plate in the other direction relative to the carriage; second back and forth movement means, having a follower engaged with the other direction driving grooved cam formed on the grooved cam plate, for guiding the second presser from a second resting position, which is different from the first resting position, to a pressing position in conjuntion with displacement of the follower on movement of the grooved cam plate in the one direction relative to the carriage, and for guiding the second presser from the pressing position to the second resting position in conjunction with displacement of the follower on movement of the grooved cam plate in the other direction relative to the carriage; wherein, movement traces of the first and second pressers are determined in the first and the second back and forth movement means so that interference of the first and second pressers with one another is prevented on movement thereof. More advantageously, the grooved cam plate comprises a grooved cam which is formed thereon in order to control a position of a brush having a function for opening a latch of a latch needle and the grooved cam plate, and the knitted fabric presser further comprises means, which has a follower engaged with the grooved cam, for drawing back the brush from a functioning position thereof when either the first presser or the second presser means in the proximity of a gap, in conjuntion with displacement of the follower. Furthermore, the said first and the second back and forth movement means advantageously comprise first and second linking mechanisms for moving the first and second pressers respectively and a one piece of each linking mechanism is driven to move in accordance with displacement of each follower. Furthermore, advantageously, one direction and the other direction driving grooved cams are respectively formed in two stages on the grooved cam plate; the first and the second back and forth movement means having a first and second linking mechanisms for moving first and second pressers respectively; and two pieces of each linking mechanism being connected with the followers engaged respectively with the grooved cams formed in the twee upper and lower stages and being driven to more in accordance with displacement of each follower. According to the invention the first and second pressers are installed at the same carriage, because the pressers press a knitted fabric on movement of the carriage in one direction and in the other direction, respectively. Each presser is actuated by reciprocating motion of a grooved cam plate relatively to the carriage. In the grooved cam plate are formed a grooved cam for driving one of the pressers in one direction and that for driving the other thereof in the other direction. The first and second pressers are moved reciprocally between a pressing position inside a gap and a resting position outside the gap by first and second back and forth movement means having a follower engaged with each grooved cam. Since the first resting position for the first presser is different from the second resting position for the second presser, and movement traces are determined so as to avoid interference with each other, the pressing position of each presser is allowed to over-lap with one another and therefore a pressing unit can be realized which has a constitution capable of bi-directional switching only in a one unit. Further, according to the invention, a grooved cam is formed on the grooved cam plate for controlling a position of a brush which has the function to open a latch of latch needle. The brush is drawn back from the functioning position thereof, when either the first or second presser moves near the gap. Since the brush does not contact with the presser on moving of the presser, the brush can be prevented from wearing and the presser can be smoothly moved. Since the timing for drawing back the brush is controlled by the grooved cam, the flexibility on synchronizing with the movement of the presser can be enhanced. Furthermore, according to the invention, each of the first and the second back and forth movements means has a linking mechanism, and one piece of each linking mechanism is driven to move in conjunction with displacement of a follower engaged with a grooved cam. Therefore, it is easily realized to determine movement traces of the pressers so as to be prevented from interfering with each other, for example, by varying the length of each piece constructing the linking mechanism. Furthermore, according to the invention, the grooved cams are formed in two upper and lower stages. Two pieces of the linking mechanisms for moving the first and the second pressers are respectively driven to displace in association with a follower which is displaced by engaging with each groove of the upper and the lower stages, which enables to move the presser between a pressing position inside the gap and a resting position outside the gap. The first and second pressers can be prevented from interfering with each other by changing a phase of the grooved cams formed in double form or changing the ratio of pieces constructing the linking mechanism. As described above, according to the invention, it is possible to easily switch pressers to be used in accordance with a movement direction of a carriage in a one unit by providing a one carriage reciprocally moving in longitudinal directions of a needle bed with pressers dedicated for each direction. In addition, it is also possible to press on a corresponding needle bed side only, for example, by providing respectively front and rear carriages of V bed type flat knitting machine with respective pressers for forth and back movements. For example, when only a needle bed on one side is used for knitting, although it is impossible to satisfactorily press a stitch only by pressing just under the gap because no loop is formed between the front and rear needle beds, satisfactory pressing of stitch is made possible by shifting a pressing position to the side of the used needle bed. Furthermore, satisfactory pressing of stitch can be realized by providing carriages for front and rear needle beds with respective pressers for forth and back movements, even if a double plain stitch fabrics are knitted to form a cylindrical fabric by independently using each of the front and rear needle beds. Furthermore, according to the invention, it is easy to determine a proper timing for preventing a brush from wearing because, when either the first or second presser is moved near the pressing position, the brush can be drawn back from the functioning position thereof by providing a grooved cam plate with a grooved cam for controlling position of the brush. Furthermore, according to the invention, it is easy to determine the movement traces of the first and second pressers to be moved not to interfere with each other, for example, by changing the ratio of the pieces constructing the linking mechanism, because a piece of each linking mechanism is driven to displace by the one direction and the other direction driving groove cams respectively. Furthermore, according to the invention, it is easy to determine the movement traces of the first and second pressers to be moved not to interfere with each other by changing the phase of the grooved cams in two steps or changing the ratio of the pieces of the linking mechanism, because the grooved cams for driving the first and second pressers are formed in two upper and lower stages, respectively, and respective two pieces of the first and second linking mechanisms for each of the first and second pressers are driven to displace in conjunction with the grooved cams in two stages. 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 an elevational view which illustrates an embodiment of the invention; Fig. 2 is a sectional view taken along the cutting plane line II-II of Fig. 1; Fig. 3 is a sectional view taken along the cutting plane line III-III of Fig. 1; Fig. 4 is an elevational view which illustrates other working state of the embodiment shown in Fig. 1; Fig. 5 is a sectional view taken along the cutting plane line V-V of Fig 4; Fig. 6 is a sectional view taken along the cutting plane line VI-VI of Fig. 4; Fig. 7 is an elevational view which illustrates a further working state of the embodiment shown in Fig. 1; Fig. 8 is a sectional view taken along the cutting plane line VIII-VIII of Fig. 7; Fig. 9 is a sectional view taken along the cutting plane line IX-IX of Fig. 7; Fig. 10 is a plan view of a grooved cam plate 3 shown in Fig. 1; Fig. 11 is a plan view which illustrates a part of the embodiment shown in Fig. 1; Fig. 12 is a bottom view which illustrates a part of the embodiment shown in Fig. 1; Fig. 13 is a schematic sectional view which illustrates traces of head of pressers in the embodiment shown in Fig. 1; Fig. 14 is a sectional view taken along the cutting plane line XIV-XIV of Fig. 1; Fig. 15 is a schematic elevational view which illustrates a driving mechanism of other embodiment of the invention; Fig. 16 is a plan view of a grooved cam of the embodiment shown in Fig. 15; Fig. 17 is a sectional view taken along the cutting plane line XVII-XVII of Fig. 15; Fig. 18 is a sectional view which illustrates a state to which a second presser shifts from the state shown in Fig. 17; Fig. 19 is a sectional view which illustrates a state to which the second presser further shifts from the state shown in Fig. 18; and Fig. 20 is a schematic sectional view which illustrates an operating condition of a knitted fabric presser of a V-bed type flat knitting machine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Now referring to the drawing, preferred embodiments of the invention are described below. Figs. 1 to 14 show constitutions and operating states of an embodiment of the invention. Figs. 1 to 3 show pressing states with a first presser 1. Figs. 4 to 6 show resting states of first and second pressers, and Fig. 7 to 9 show pressing states with the second presser 2. Figs. 1, 4 and 7 show elevational views. Figs. 2 and 3 show sectional views taken along the cuttig plane lines II-II and III-III of Fig. 1, respectively. Figs. 5 and 6 show sectional views taken along the cutting plane lines V-V and VI-VI of Fig. 4, respectively. Figs. 8 and 9 show sectional views taken along the cutting plane lines VIII-VIII and IX-IX of Fig. 7, respectively. Needle beds are not illustrated in Figs. 1, 4 and 7. Pressers apart from the cutting plane lines are illustrated only in end faces in Figs. 2, 3, 5, 6, 8 and 9. The first presser 1 is used for pressing a knitted fabric when a carriage is moved to the left hand direction of Figs. 1, 4 and 7 for knitting. The second presser 2 is used when the carriage is moved to the right hand. The actuation of the first and second pressers 1, 2 is switched by grooved cams 4, 5 for driving in one direction and the other direction, respectively, which are formed in a grooved cam plate 3. A grooved cam 6 for driving a brush 7 is also formed on the grooved cam plate 3, by which the brush 7 can be drawn back in order to be prevented from wearing when the first and second pressers 1, 2 are moving. The pressing action by the first and second pressers 1, 2 is performed inside a gap 10 between a front needle bed 8 and a rear needle bed 9. A knitted fabric pressing unit of the embodiment is arranged on an upper end of a carriage 11 moving on a rear needle bed 9. A bracket 12 is attached on an end face of the carriage 11. The bracket 12 mechanically supports various parts of the knitted fabric pressing unit of the embodiment. The grooved cam plate 3 is inserted to the carriage 11 side of the bracket 12 so as to be slidable in a longitudinal direction of the needle bed 9. The grooved cam plate 3 is supported by a keeping plate 13 for a grooved cam. When the grooved cam plate 3 slides in a longitudinal direction of the needle bed, sliding plates 14, 15 for driving in one direction and the other direction are shifted respectively to a direction vertical to the longitudinal direction by the grooved cams 4, 5 for driving in one direction and the other direction, respectively, in conjunction with the displacement of followers 16, 17. On the other hand, the sliding plates 14, 15 are kept to be slidable by keeping plates 18, 19, respectively for sliding plates 14, 15. The displacement of the sliding plate 14 for driving in one direction is transmitted to a first linking mechanism composed of a first support arm 20, a first front arm 21, a first rear arm 22 and a first slide arm 23. The sliding plate 14 for driving in one direction and the first linking mechanism are included in first back and forth movement means. The follower 16 is displaced to a direction vertical to the longitudinal direction of the needle bed by sliding of the grooved cam plate 3 to a longitudinal direction of the needle bed. The sliding plate 14 for driving in one direction is slidably displaced in conjunction with the displacement of the follower 16 and causes the displacement of the first rear arm 22 via the first drive arm 23. Each of the first front arm 21 and the first rear arm 22 is axially supported at one end thereof with the bracket 12 and at the other end thereof with the support arm 20. When the first rear arm 22 is driven to displace by the drive arm 23, the first support arm 20 is driven to displace because the point axially supported by the bracket 12 is fixed. A first spring 24 is provided for the purpose of supplying pressure for the first presser 1 when pressing stitches. In a similar manner, the displacement of the sliding plate 15 for driving in the other direction is transmitted to a second linking mechanism composed of a second support arm 25, a second front arm 26, a second rear arm 27 and a second drive arm 28. The sliding plate 15 for driving in other direction and the second linking mechanism are included in second back and forth movement means. A second spring 29 provides pressure when the second presser 2 is in the pressing position. Relative movement of the grooved cam plate 3 is performed by a motor 30 which is driving means. The motor 30 is fixed to the bracket 12 via a mounting plate 31. A rotation axis of the motor 30 is extended vertically downward in a direction perpendicullar to a longitudinal direction of the needle bed and a pinion 32 is fixed to the axis for displacing the grooved cam plate 3. A sliding plate 33 for a brush is provided with a follower 34 and a brush mounting plate 35. The follower 34 is engaged with the grooved cam 6 for driving a brush. The brush 7 is attached to the brush mounting plate 35. In such a manner, since the position of the brush 7 is controlled in accordance with the grooved cam 6 for driving the brush, the flexibility as to set timing can be enhanced. The rotation axis of the motor 30 is also extended to the side of the mounting plate 31 and an angle detection piece 36 is attached to the axis. A rotation angle of the motor is detected by a first sensor 37 provided in relation with the angle detection piece 36. A second sensor 38 is attached to the side of the bracket 12 positioned on the side of the sliding plate 14 for driving in one direction. A third sensor 39 is attached in the proximity of the pinion 32. A position detection hole 40 is formed in the grooved cam plate 3 in association with the third sensor 39. Each of the sensors 37 to 39 is realized by using a proximity sensor. On the bracket 12, stoppers 41, 42 are formed in order to stop the displacement of each linking mechanism when the first and second pressers 1, 2 are in the resting position thereof. The stoppers 41, 42 prevent a state that each linking mechanism cannot be driven to displace toward a reverse direction because each linking mechanism is over driven beyond the dead point thereof. Furthermore, since a first resting position where the first presser 1 is waiting and a second resting position where the second presser 2 is waiting are made to be differently positioned as shown in Fig. 4 to 6, no interference occurs even if both the first and second pressers 1, 2 are put on non-functioning condition. Fig. 10 is a plan view of the grooved cam plate 3; Fig. 11 is a plan view which illustrates a constitution in relation to the first and second sensors 37, 38, and Fig. 12 is a bottom view which illustrates a state that the grooved cam plate 3 is driven by the pinion 32. On the grooved cam plate 3 are formed the grooved cam 4 for driving in one direction, the grooved cam 5 for driving in the other direction, the grooved cam 6 for driving the brush, and the position detection hole 40. Each of the grooved cams 4, 5 for driving in one direction and other direction has horizontal and inclined portions. When the followers 16, 17 are positioned on the horizontal portions, the corresponding pressers 1, 2 are in the resting position thereof. On the other hand, the followers 16, 17 are positioned on the top of the inclined portion, the corresponding pressers 1,2 are on the pressing position thereof. The grooved cam 6 for driving the brush is formed in W-letter shape and draws back the brush from the functioning position thereof for a period when each of the pressers 1, 2 is moved from the pressing position to the resting position thereof. A rack 43, which is engaged with the pinion 32, is formed on the upper portion of the grooved cam plate 3. The first sensor 37 is a proximity sensor, which detects a metal piece etc. in approaching. On the assumption that the first sensor's position is considered as an origin where its output is set to be on on-state when both the first and second pressers 1, 2 are in the resting condition, as shown in Figs. 4 to 6, but the first sensor 37 is set to be on off-state when the grooved cam 3 is shifted from the origin toward the left side, namely, toward the side shown in Figs. 7 to 9, no matter how little that may be. The second sensor 38 is also a proximity sensor, which is put to on-state, when the grooved cam plate 3 is positioned on the left side of the origin. The third sensor 39 provided in relation with the position detection hole 40 is also a proximity sensor, which is put to on-state when the grooved cam plate 3 is on the right side of the origin as shown in Figs. 1 to 3. Fig. 13 illustrates movement traces of the first and second pressers 1, 2 of the embodiment. The traces of the head of the first presser 1 are referred to by 1a, 1b, 1c, 1d and 1e, and those of the second presser 2 are referred to by 2a, 2b, 2c, 2d and 2e. While the positions 1e, 2e of the heads of the first and second pressers 1, 2 are identical on pressing stitches inside the gap 10, the resting positions 1a, 2a of the first and second pressers, respectively, are different from each other. The head traces of the pressers on moving are set to prevent the pressers from interfering with each other. Such setting can be realized by changing the length of each arm constituting the first and second linking mechanisms or changing the position of the portion supported axially with the bracket 12. Furthermore, the movement traces are set to prevent the pressers from contacting with each sinker 44 of the needle beds 8, 9. In addition, a brush for opening a latch 46 of a latch needle 47 composed of a hook 45 and the latch 46 can be prevented from wearing due to contacting with the pressers, because the brush is drawn back from the gap 10 on movement of the pressers. Fig. 14 illustrates a constitution for preventing the brush 7 from wearing. The constitution corresponds with a sectional view taken along the cutting plane line XIV-XIV of Fig. 1. The follower 34 provided in the sliding plate 33 for a brush is driven to displace by sliding of the grooved cam plate 3 and the brush mounting plate 35 and the brush 7 are moved via a brush mounting base 48. Figs. 15 to 19 illustrate constitutions and operations of another embodiment of the invention. Each part corresponding to the embodiment shown in Figs. 1 to 14 is identified by the same reference signs. It is remarkable that a slider 50, a first grooved cam plate 51 and a second grooved cam plate 52 are provided in place of the grooved cam plate 3. Fig. 15 illustrates a drive mechanism for reciprocally moving the slider 50 in longitudinal directions of needle beds. Rotational motion of a motor 53, which is driving means, is converted from a crank 54 through a connecting rod 55 to linear motion as indicated by movement directions 56. Fig. 16 illustrates the slider 50 and grooved cams which are formed in two up and down stages on the first and second grooved cam plates 51, 52. A grooved cam 61 for upper side is formed on the first grooved cam plate 51. A grooved cam 62 for lower side is formed on the slider 50 under the grooved cam 61 for upper side. The grooved cam 61 for upper side and the grooved cam 62 for lower side are identical in end portions 63, 64 on pressing position and resting position sides, but not identical in the inclined portions therebetween. Also on the second grooved cam plate 52 is formed a grooved cam 66 for upper side and a grooved cam 67 for lower side is correspondingly formed on the slider 50. The grooved cam 66 for upper side and the grooved cam for lower side are identical in end portions 68, 69 on pressing position and resting portion sides, but not identical in the inclined portions therebetween. Additionally, an upper portion of the end 64 of the resting position side on the first grooved cam plate 51 and an upper portion of the end 69 of the resting position side on the second grooved cam plate 52 are different in level, which is indicated by a reference sign of X. Figs. 17 to 19 are sectional views taken along the cutting plane line XVII-XVII of Fig. 15. Fig. 17 illustrates the second presser 2 in pressing position; Fig. 18 illustrates the second presser 2 which is being set apart from the gap 10; and Fig. 19 illustrates the second presser 2 in restiing position. The second presser 2 is attached on a presser mounting base 70. The presser mounting base 70 constitute a linking mechanism together with an upper side sliding member 71 and a lower side sliding member 72. The upper side sliding member 71 slides in conjunction with displacement of an upper side follower 73 engaged with the grooved cam 66 for upper side formed on the second grooved cam plate 52. The lower side sliding member 72 slides in conjunction with displacement of a lower side follower 74 engaged with the grooved cam 67 for lower side formed on the slider 50. A groove 71b is formed on a top portion 71a of the upper side sliding member 71 and a lower portion of the presser mounting base 70 is axially supported by a pin 76 provided on a top of the lower side sliding member 72. Pressing pressure of the second presser 2 is provided by a spring 77. The pressing power by the spring 77 is adjusted by a bolt 78. The first presser 1 is driven similarly. Since a difference between the grooved cam 66 for upper side and the grooved cam 67 for lower side is large in the inclined portion of the grooved cams of the embodiment, the second presser 2 is prevented from contacting with heads of the front and back needle beds, 8, 9 when the second presser 2 moves in the proximity of the gap, as shown in Fig. 18. In addition, as shown in Fig. 16, the respective resting positions of the first and second pressers can be different even if both the pressers 1,2 are in resting state, because there is a differnce in level between the end 64 of the resting positon side for the first presser 1 and the end 69 of the resting position side for the second presser 2, which is indicated by a reference sign of X. Furthermore, movement traces of the first and second pressers 1, 2 can be also changed by changing a stopping position given by the pin 75 on the presser mounting base 70 and the groove 71b formed on the top 71a of the upper side sliding member 71. Advantageously, a grooved cam for moving the brush 7 can be formed in order to prevent the brush 7 from wearing also in this embodiment like the embodiment shown in Figs. 1 to 14. Furthermore, advantageously, although the grooved cam 3 and the slider 50 are driven by the motors 30, 53, solenoidal, pneumatic or hydraulic means can be also used in place thereof. Various modifications of the present invention will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims.

Claims: A knitted fabric presser assembly for a flat knitting machine, installed on a carriage (11) movable in opposite longitudinal directions of needle beds (8, 9) of the said flat knitting machine and comprising: a first presser (1) for pressing knitted fabric upon movement of the said carriage (11) in one of said longitudinal directions; a second presser (2) for pressing knitted fabric upon movement of the said carriage (11) in the other of said longitudinal directions; and means for moving the first and second pressers (1, 2), to cause one of said first or second pressers (1, 2) to move to the respective pressing position thereof and to cause the other of said first or second pressers (1, 2) to be prevented from interfering with each other during movement thereof, wherein first and second rest positions for the pressers are provided at different distances from the pressing position by first and second back and forth movement assemblies operatively connected to driving means, characterized in that the knitted fabric presser assembly is installed as a single unit on said carriage (11) for pressing fabric knitted by the knitting machine, wherein the said first and second pressers are installed on the same carriage, the presser unit being installed at a carriage for one needle bed. A knitted fabric presser of a flat knitting machine as claimed in claim 1, wherein the moving means comprises: a grooved cam plate (3) being capable of reciprocal movement relative to the carriage (11) and having a grooved cam (4) for driving in one direction of the reciprocal movement and a grooved cam (5) for driving in the other direction of the reciprocal movement, the grooved cams (4, 5) being formed on the grooved cam plate (3); means for driving the grooved cam plate (3) relatively to the carriage (11); first back and forth movement means, having a follower (16) engaged with the grooved cam (4) for driving in the one direction formed on the grooved cam plate (3), for guiding the first presser (1) from a pressing position to a first resting position where the knitted fabric is not pressed in conjunction with displacement of the follower (16) on movement of the grooved cam plate (3) in the one direction relative to the carriage (11), and for guiding the first presser (1) from the first resting position to the pressing position in conjunction with displacement of the follower (16) on movement of the grooved cam plate (3) in the other direction relative to the carriage (11); second back and forth movement means, having a follower (17) engaged with the grooved cam (5) for driving in the other direction formed on the grooved cam plate (3), for guiding the second presser (2) from a second resting position, which is different from the first resting position, to the pressing position in conjunction with displacement of the follower (17) on movement of the grooved cam plate (3) in the one direction relative to the carriage (11), and for guiding the second presser (2) from the pressing position to the second resting position in conjunction with displacement of the follower (17) on movement of the grooved cam plate (3) in the other direction relative to the carriage (11). A knitted fabric presser of a flat knitting machine as claimed in claim 2, wherein a grooved cam (6) is formed on the grooved cam plate (3) in order to control a position of a brush (7) having a function for opening a latch (46) of a latch needle (47), further comprising means, which has a follower (34) engaged with the grooved cam (6), for drawing back the brush (7) from a functioning position thereof when either the first presser (1) moves or the second presser (2) moves in proximity of a gap (10), in conjunction with displacement of the follower (34). A knitted fabric presser of a flat knitting machine as claimed in claim 2, wherein each of the first and the second back and forth movements means has first and second linking mechanisms for moving the first and second pressers (1, 2) respectevely, and a one piece of each linking mechanism is driven to move in accordance with displacement of each of the followers (16, 17). A knitted fabric presser of a flat knitting machine as claimed in claim 2, wherein the grooved cam (61, 62) for driving in one direction and the grooved cam (66, 67) for driving in the other direction are respectively formed in two upper and lower stages on the grooved cam plate (50, 51, 52), each of the first and the second back and forth movement means having first and second linking mechanisms for moving the first and second pressers (1, 2) respectively, and two pieces of each linking mechanism being connected with the followers (73, 74) engaged with the grooved cams (61, 62, 66, 67) formed respectively in the two upper and lower stages and being driven to move in accordance with displacement of each follower (73, 74). A knitted fabric presser of a flat knitting machine as claimed in claim 1, wherein the first and second pressers (1, 2) press the knitted fabric inside a gap (10) between front and rear needle beds (8, 9) of a flat knitting machine of V-shaped bed type, and the movement traces are determined so that the first and second pressers (1, 2) do not contact with noses of the front and rear needle beds (8, 9).

Inventors: HIRAI IKUHITO, NAKAMORI TOSHINORI, HIRAI, IKUHITO, NAKAMORI, TOSHINORI
Applicants: SHIMA SEIKI MFG, SHIMA SEIKI MFG., LTD.
Application year: 1993
Main classification: D04B15
IPC codes: D04B15