Circular knitting machine with jacquard pattern control mechanism for cylinder needles, sinkers or dial needles

Abstract: The present invention provides a jacquard pattern control mechanism for a circular knitting machine in which knitting instrumentalities (26) are selected in accordance with a jacquard pattern and are moved between three positions, namely, welt, tuck and knit positions, by a selector jack (34), a rocker base (41) a rocker bar (44) pivotally mounted on the rocker base and control cams (32,38,48) for controlling the knitting instrumentality, selector jack, rocker base and rocker bar. Electromagnetic selection mechanisms (53,55,56) attract selected portions of the rocker bar (44) to determine to which position the knitting instrumentality will be moved. The selection mechanisms are more compact and have shorter strokes to permit selection of all types of knitting instrumentalities and all three positions without reducing the number of yarn feeds.

Description: The present invention relates to circular knitting machines and more particularly to a jacquard control mechanism for cylinder needles, sinkers or dial needles. Circular knitting machines are of either the single knit type or the double knit type. Single knit circular knitting machines typically include a rotating needle cylinder with knitting needles slidably mounted in grooves therein and a sinker cap with sinkers slidably mounted in grooves therein mounted on top of the needle cylinder for rotation therewith. Double knit circular knitting machines include a rotating needle cylinder and a rotating dial associated therewith. The needle cylinder has cylinder needles slidably mounted in vertical grooves therein while the dial has dial needles slidably mounted in horizontal, radial grooves therein. In EP 0.851.051 A there is disclosed a jacquard pattern control mechanism for a single knit circular knitting machine for control of cylinder knitting needles and sinkers. While such jacquard pattern control mechanism constitutes a considerable advance over prior jacquard pattern control mechanisms, it still has various limitations and disadvantages. Among such limitations and disadvantages is an inability to be used to control dial needles because of the requirement that the control mechanism must be made smaller so that it will fit in the space available toward the center of the dial. Also, difficulty is frequently encountered with prior such pattern control mechanisms in moving the knitting instrumentalities to the welt, tuck and knit positions. EP-A-0 249 203 describes an electromagnetic selector device for a flat bed knitting machine, in which the selector is supported by a carriage which reciprocates above the needle bed so that an attracting, select face of the selector moves across and in contact with the upper edges of selector jacks associated with the knitting needles. The sliding movement of each knitting needle is controlled by a series of jacks comprising, in sequence, a jack connected to the knitting needle, a positioning jack and a support jack disposed in the needle groove in the needle bed, with the selector jack being loosely fitted centrally on a protuberance of the support jack. It is an object of the present invention to provide a jacquard pattern control mechanism for controlling all types of knitting instrumentalities of a circular knitting machine and for moving such instrumentalities between all three positions thereof, that is, welt, tuck and knit positions. The present invention consists in a circular knitting machine having movable knitting instrumentalities and a jacquard pattern control mechanism for said instrumentalities comprising a rocker base movably mounted in spaced relation to each of said knitting instrumentalities for sliding movement in alignment with an in the same direction as the knitting instrumentality, a selector jack having a butt projecting from one side thereof and disposed between the rocker base and the knitting instrumentality for assisting in controlling the selection and movement of the knitting instrumentality, a rocker bar pivotally mounted on the rocker base for rocking movement about a medial pivot relative to said rocker base and having attractable portions at opposite ends thereof which when attracted cause the rocker bar to rock about its pivot, magnetic attracting means mounted adjacent said attractable portions of the rocker bar for selectively attracting said attractable portions, and first control cam means for controlling the knitting instrumentality, second control cam means for engaging the butt of the selector jack and controlling said selector jack, characterised by intermediate cam means for controlling the rocker base and for moving the rocker base relatively to the selector jack, an inverse trapezoidal projection extending from the side of the selector jack opposite to its butt, and a trapezoidal projection on a side of the rocker base adjacent the selector jack projection, said selector jack projection being movable backward and forward of the trapezoidal projection, and said selector jack being movable away from the rocker base upon relative movement of said rocker base and said selector jack by coaction between said selector jack and rocker base projection so that the circumferential stroke may be shortened and three positions of said knitting instrumentality selected. In order that the present invention may be more readily understood, reference will now be made to the accompanying schematic drawings, in which: Figure 1 is a fragmentary, schematic view of a cam block and controlling cams of the jacquard control mechanism of the present invention; Figure 2 is a section taken substantially along line 2-2 of Figure 1; Figure 3 is a fragmentary vertical section of a double knit circular knitting machine incorporating the pattern control mechanism of the present invention installed on the dial of the knitting machine; Figure 4 is an enlarged, somewhat schematic view of the dial needle, selector jack, rocker base and rocker of the jacquard pattern control mechanism shown in Figure 3; Figures 5A through 5F, inclusive, are sectional views taken substantially along lines 5A through 5F, inclusive, in Figure 1; Figure 5G is a sectional view similar to Figure 5F in a different operational position; Figure 5H is a sectional view similar to Figure 5E in a different operational position; Figure 6 is a view similar to Figure 1 of another embodiment of the present invention; and Figure 7 is a view similar to Figure 4 of the knitting needle and pattern control mechanism of the embodiment illustrated in Figure 6. Referring now more specifically to the drawings and particularly to Figures 1-5H, there is illustrated schematically and sectionally the core part of a circular knitting machine, generally indicated at 20, which incorporates the jacquard pattern control mechanism of the present invention. Circular knitting machine 20 includes a rotary needle cylinder 21 having a multiplicity of grooves (not shown) therein. A knitting needle 22 is mounted for vertical sliding movement in each of the grooves in the needle cylinder 21 (Figure 3). Circular knitting machine 20 further includes a cam block 23 mounted outside the needle cylinder 21 and mounts a needle cam 24 for raising and lowering the needles 22 between an active (knit) position and an inactive (welt) position. Additional cams may be provided for moving needles 22 to a tuck position. A rotary dial 25 is mounted on top of the needle cylinder 21 and has a multiplicity of grooves (not shown) extending radially from the outer periphery to the inner periphery thereof. A dial needle 26 is slidably mounted in each of the grooves in dial 25 for movement between welt, tuck and knit positions. Dial needle 26 preferably has at least one butt 26a thereon and a semicircular indentation 26b in the upper surface thereof from which the butt 26a extends (Figure 4). A dial cam block 30 is mounted above the dial 25 and mounts on its lower surface dial needle control cams, generally indicated at 31, in facing relation to the grooves in dial 25. Dial needle control cams 31 include outer guard cams 32 and stitch cams 33 which define a cam track T 1 for the butt 26a of dial needle 26. Stitch cams 33 are mounted for radial adjustment to control the density of the fabric. A selector jack 34 is disposed in each dial groove in dial 25 inwardly of dial needle 26 (Figures 2-4). Selector jack 34 has a butt 34a thereon which has a first vertical edge 34b and a second vertical edge 34c (Figure 4). Selector jack 34 has an inverse trapezoidal projection 34d from the side thereof opposite butt 34a. A circular projection 34e projects from the end portion of selector jack 34 opposite the end portion having butt 34a thereon, and projection 34e is received in indentation 26b on dial needle 26 . Cam block 30 mounts selector jack control cams, generally indicated at 35, including cancelling cams 36, additional cancelling cams 37 and selector jack raising cams 38 defining a cam track T 2 . Cam track T 2 receives butt 34a on selector jack 34 and controls and moves selector jack 34. A rocker base 40 (Figures 2-4) is slidably mounted in each dial groove partially outwardly of selector jack 34. Rocker base 40 includes an outer end section 41 , the lower portion of which is received in the dial groove and the upper portion of which includes first and second spaced apart trapezoidal projections 41a and 41b which coact with projection 34d on selector jack 34. Additionally, rocker base 40 includes a butt 42 projecting upwardly therefrom. Butt 42 includes a first vertical edge 42a and a second vertical edge 42b. The outer end section 41 of rocker base 40 has a first indentation 41c between projections 41a and 41b and a second indentation 41d between projection 41b and the first vertical edge 42a of butt 42 to receive therein projection 34d of selector jack 34. Rocker base 40 includes a medial section 43 having a central portion 43a and opposite end portions 43b and 43c. The lower portion of medial section 43 is received in the dial groove, and the central portion 43a has a recess or socket 43d in the upper portion thereof. A rocker bar 44 is mounted on the medial section 43 of rocker base 40 for pivotal movement by a circular pivot protrusion 44a which is received in socket 43d. Rocker bar 44 has symmetrical opposite end portions 44b and 44c which are beveled, wedge-shaped at their outer extremities at 44d and 44e. The lower portions of opposite end portions 44b and 44c are bulbous-shaped and serve to engage the upper edges of end portions 43b and 43c of medial section 43 of rocker base 40 to limit the pivotal movement of rocker bar 44. The upper sections 44f and 44g of end portions 44b and 44c are magnetically attractable and are raised above the central portion of rocker bar 44. Rocker base control cam 46 is carried by cam block 30 adjacent selector jack raising cam 38. Cam 46 has a first side edge 46a which is spaced from side edges 38a of cams 38 to define therewith a cam track T 3 which receives and controls butt 42 on rocker base 40. Rocker base control cam 46 has a second side edge 46b which is positioned to engage wedge-shaped end 44d of rocker bar 44 when rocker bar 44 is pivoted to have end portion 44b extended. First side edge 46a of rocker base cam 46 has spaced apart indentations 46c and 46d therein which permit rocker base 40 to be moved inwardly a short distance. Second side edge 46b of rocker base cam 46 has protrusions 46e and 46f opposite indentations 46c and 46d to retract rocker bar 44 and thus rocker base 40. A rocker bar guard cam 48 is mounted on cam block 30 and has a side edge 48a spaced from side edge 46b of rocker base cam 46 a distance equal to the length of rocker bar 44 and defining therewith a cam track T 4 . Side edge 48a engages the wedge-shaped end 44e when rocker bar 44 is pivoted to position end portion 44c in extended position. Cam 48 has spaced apart indentations 48b and 48c opposite and aligned with protrusions 46e and 46f on second side edge 46b of cam 46. A magnetic attraction selection device, generally indicated at 50, is positioned immediately upstream of protrusions 46e and 46f of cam 46 and indentations 48a and 48b of cam 48 and above the path of travel of rocker bar 44 such that the rocker bar 44 on the rocker base 40 passes closely therebeneath. Selection device 50 includes two pairs of magnetic attraction means 51 and 52 (Figure 1) disposed in position to attract magnetically the magnetic attractable sections 44f and 44g, respectively, of rocker bar 44 when rocker bar 44 passes therebeneath. Preferably, the pairs of magnetic attraction means 51, 52 comprises permanent magnets 53, 54 in the center and first and second electromagnets 55, 56 and 57, 58 on opposite sides of permanent magnets 53, 54, respectively. Permanent magnets 53, 54 and electromagnets 55-58 are all supported by a support member 59. For a more complete description of this selection system, reference is made to EP 0 851 051 A. Referring now to Figures 5A-5H, a series of operations of the first embodiment of this invention will now be described. When an individual dial needle 26 and its associated selector jack 34, rocker base 40 and rocker bar 44 approach selection means 50, rocker cancelling cams 60, 61 place the rocker bar 44 in the neutral position shown in Figure 5A. If it is desired to move dial needle 26 to the knit position, a signal is sent from a controller (not shown) to electromagnet 55 which attracts attractable portion 44f of rocker bar 44. Rocker bar 44 then moves past electromagnet 55 and the wedge-shaped end 44d of rocker bar 44 engages protrusion 46e of side edge 46b of cam 46 . Rocker bar 44 is thus pushed inwardly of the knitting machine 20 along with rocker base 40 (Figure 5B). Selector jack 34 has the projection 34d thereon riding up on projection 41b of rocker base 40 as rocker base 40 moves to the left as seen in Figure 5B. This positions butt 34a on selector jack 34 to engage first rising part 38a of selector jack raising cam 38 and selector jack 34 moves to the tuck position along with dial needle 26. Dial needle 26 is pivotally linked to selector jack 34 by portion 34e and recess 26b (Figure 5C). Next, signals are sent to electromagnet 57 which attracts attractable portion 44f of rocker bar 44 (Figure 5D). As rocker bar 44 passes electromagnet 57, the wedge end 44d engages the second protrusion 46f of side edge 46b of cam 46 and rocker bar 44 and rocker base 40 are pushed inward (Figure 5D). Such inward movement of rocker base 40 causes projection 34d on selector jack 34 to ride up on projection 41a on rocker base 41 (Figure 5E). Butt 34a on selector jack 34 engages the second rising part 38b on cam 38, and selector jack 34 moves dial needle 26 from the tuck position to the knit position (Figure 5F). Once the dial needle 26 is moved to the knit position by the selector jack 34, it is lowered to the welt position by outer guard cam 32 and stitch cam 33 (Figure 5G). The pattern selection means is then in position for the next needle selection cycle. If it is desired that dial needle 26 be moved only to the tuck position, the dial needle 26 is moved to the tuck position as described above in connection with Figures 5A-5C. However, instead of electromagnet 57 being energized as described previously, electromagnet 58 is energized to attract attractable portion 44g of rocker bar 44 (Figure 5H). At the same time, cancelling cam 36 in cam track T 2 pushes down butt 34a on selector jack 34 which causes projection 34d on selector jack 34 to remain in the recessed space between projection 41a and 41b. Concurrently, the opposite end of rocker bar 44 passes beneath projection 46f on side edge 46b of cam 46. Therefore, the dial needle 26 remains in the tuck position until dial needle 26 is lowered to the welt position by the stitch cam 33. If it is desired for the dial needle 26 to maintain the welt position, signals are sent to electromagnet 56 which attracts attractable portion 44g of rocker bar 44. At the same time, cancelling cam 37 in cam track T 2 lowers butt 34a of selector jack 34 and selector jack projection 34d remains to the left of projection 41b on rocker base 41 (Figure 5G). Concurrently, the opposite end of rocker bar 44 passes beneath projection 46e on side edge 46b of cam 46. The dial needle 26 will not be affected by the rocker base 40 and will not move from the welt position. In Figure 1, the lines T 1k , T 1t and T 1w indicate the tracks of butt 26a of dial needle 26 as it moves with dial 25 and as dial needle 26 is moved between these three positions. The lines T 3k , T 3t and T 3w indicate the tracks of butt 42 on rocker base 40 as rocker base 40 moves with dial 25 and is moved by cam projections 46e and 46f and by cam track T 3 to positions corresponding to the knit, tuck and welt positions of dial needle 26 . Referring now to Figures 6 and 7, there is illustrated a further embodiment of this invention. In this embodiment, a knitting needle 226 is provided and has a butt 226a thereon. A selector jack 234 is substantially identical to the previously described selector jack 34 and has a butt 234a thereon. A rocker base 240 is also substantially identical to rocker base 40 and has a butt 242 thereon. A rocker bar 244 is pivotally carried by rocker base 240 and is substantially identical to rocker bar 44. Needle control cams 231 are provided and include outer guard cams 232, stitch cams 233, inner guard cams 280, and tuck cams 281, all of which define a cam track T 111 . Cam track T 111 receives butt 226a on needle 226 and moves needle 226 between the welt and knit positions. Selector jack control cams 235 are provided on cam block 230 and include selector jack cancelling or deflecting cams 236 and 237 and selector jack raising cams 238. Selector jack raising cam 238 is formed in two parts, the first part 238a being a tuck-raising part and the second part 238b being a knit-raising part near the top of the tuck position. For support needle selection of needle 226, selector jack 234 is caused to rise up part 238a of cam 238 to the tuck position. Part 238b of cam 238 is withdrawn to a position where it will not be engaged by butt 234a on selector jack 234 such that needle 226 remains in the tuck position. Needle butt 226a moves along tuck cam 281 and outer guard cam 232 until it engages inner guard cam 280 which causes the needle 226 to be lowered toward the welt position. The track of butt 226a of needle 226a along cam track T 111 is represented in Figure 8 as T 111r , while the welt position track is indicated as T 111w . This pattern selection mode permits the selection of two positions, i.e. the support position and the welt position. However, if inner guard cam 280 is withdrawn to a position out of the path of butt 226 of needle 226 , then three positions can be selected. As described herein, the pattern control mechanism of the present invention permits needle or other knitting instrumentality selection for three positions, i.e. welt, tuck and knit (or even support) based upon pattern signals from a controller to produce a jacquard fabric of a variety of different patterns. While principally described herein in association with dial needles, the present invention is not confined thereto, but can be widely applied to guiding selectively any knitting instrumentality, including cylinder needles, transfer needles, jacks, sinkers, etc. through at least two paths and usually three such paths. The present invention provides numerous advantages not previously available. For example, the circumferential stroke of rocker cam 46 can be shortened. As a result, the needle selecting parts of the needle selection mechanism necessary for selecting three positions can be made compact. Therefore, three positions of the needles can be selected using the same number of yarn feeds which heretofore could be selected for only two positions.

Claims: A circular knitting machine (20) having movable knitting instrumentalities (26) and a jacquard pattern control mechanism for said instrumentalities comprising a rocker base (40) movably mounted in spaced relation to each of said knitting instrumentalities (26) for sliding movement in alignment with and in the same direction as the knitting instrumentality (26), a selector jack (34) having a butt (34a) projecting from one side thereof and disposed between the rocker base (40) and the knitting instrumentality (26) for assisting in controlling the selection and movement of the knitting instrumentality (26), a rocker bar (44) pivotally mounted on the rocker base (40) for rocking movement about a medial pivot (44a) relative to said rocker base and having attractable portions (44b,44c) at opposite ends thereof which when attracted cause the rocker bar (44) to rock about its pivot (44a), magnetic attracting means (51,52) mounted adjacent said attractable portions (44b,44c) of the rocker bar (44) for selectively attracting said attractable portions (44b,44c), and first control cam means (32) for controlling the knitting instrumentality (26), second control cam means (35) for engaging the butt (34a) of the selector jack and controlling said selector jack (34), characterised by intermediate cam means (48) for controlling the rocker base (40) and for moving the rocker base relatively to the selector jack (34), an inverse trapezoidal projection (34d) extending from the side of the selector jack (34) opposite to its butt (34a), and a trapezoidal projection (41b) on a side of the rocker base (40) adjacent the selector jack projection (34d), said selector jack projection (34d) being movable backward and forward of the trapezoidal projection (41b), and said selector jack (34) being movable away from the rocker base (40) upon relative movement of said rocker base (40) and said selector jack by coaction between said selector jack (34) and rocker base projection (41b) so that the circumferential stroke may be shortened and three positions of said knitting instrumentality (26) selected. A circular knitting machine according to claim 1 wherein the selector jack (34) is connected to the instrumentality (26) and includes a circular projection (34e) extending from said opposite side of the selector jack at one end thereof and received in a semicircular recess (26b) in the knitting instrumentality. A circular knitting machine according to claim 1 or 2 wherein the rocker base (40) has another trapezoidal projection (41a) on the side thereof adjacent the selector jack projection (34d) and spaced apart from the first mentioned projection (41b), said selector jack projection being receivable in the space between said rocker base projections. A circular knitting machine according to claim 1, 2 or 3 wherein the attractable portions (44b,44c) of the rocker bar (44) have bevelled wedge shapes (44d,44e), and wherein the magnetic attracting means (55,56) has at least one projection in a side edge thereof facing said rocker bar. A circular knitting machine according to any preceding claim wherein the magnetic attracting means (51,52) comprises a permanent magnet (53) and first and second electromagnets (55,56) disposed on opposite sides of said permanent magnet. A circular knitting machine according to claim 5 wherein the permanent magnet (53) has an outer tip adjacent the rocker bar (44) which has a mushroom-shaped cross section. A circular knitting machine according to claim 5 or 6 wherein the magnetic attracting means (51,52) includes a second permanent magnet (54) spaced downstream from the first mentioned permanent magnet (53) and electromagnets (57,58) disposed on opposite sides of said second permanent magnet. A circular knitting machine according to claim 5,6 or 7 wherein the rocker base (40) has a butt on the same side as the trapezoidal projection(s) (41a,41b). A circular knitting machine according to any preceding claim wherein the second control cam means (35) for engaging the butt (34a) on the selector jack (34) is adapted to move the selector jack and the knitting instrumentality (26) from a welt position to a tuck position when said selector jack is moved away from the rocker base (40) by the first projection (41b) on the rocker base. A circular knitting machine according to claim 9 wherein the second control cam means (35) includes cancelling cam means (36) for moving the selector jack (34) back towards the rocker base (40) when it is desired to maintain the knitting instrumentality (26) in the tuck position. A circular knitting machine according to claim 9 wherein further movement of rocker base (40) relative to the selector jack (34) causes coaction between the projection (34d) on the selector jack and the second projection (41a) on the rocker base to move the selector jack away from the rocker base. A circular knitting machine according to claim 11 wherein the second control cam means moves the selector jack (34) and the knitting instrumentality (26) from the tuck position to a knit position upon movement of the selector jack away from the rocker base by said second projection (41a) on the rocker base. A circular knitting machine according to claim 12 wherein the first control cam means (32) is arranged to move the knitting instrumentality from the knit position to the welt position. A circular knitting machine according to any preceding claim wherein the jacquard pattern control mechanism is associated with a dial (25) of the machine and controls knitting instrumentalities comprising dial needles (26). A circular knitting machine according to any preceding claim wherein the jacquard pattern control mechanism is associated with the needle cylinder (21) of the machine and controls knitting instrumentalities comprising cylinder needles (22).

Inventors: IIDA YUKIARA, SHIBATA TAKAO, IIDA, YUKIARA, SHIBATA, TAKAO
Applicants: PRECISION FUKUHARA WORKS LTD, PRECISION FUKUHARA WORKS, LTD
Application year: 1997
Main classification: D04B15
IPC codes: D04B15