Dust and waste removal and collection system for double needle bed knitting machine and method of waste removal and collection

Abstract: A dust and other fiber waste removal and collection system for a double knitting machine (10) having yarn feeding and guiding means (22) and a knitting section comprising a cylinder (18) and dial (20) with cylinder needles operating within the cylinder and dial needles operating within the dial, the dust removal and collection system including a suction fan (26) for creating upwardly and inwardly flowing air streams through the knitting section and the yarn feeding and guiding means for removing dust and other fiber waste from the components thereof, an air stream receiving and confining hood (30) overlying the knitting section and defining an air passageway therethrough, the entrance end of the air passageway being disposed radially outwardly of and above the knitting section so that the upwardly flowing air stream flows outwardly of the knitting section to carry dust and other fiber waste entrained therein upwardly and outwardly from the knitting components such that no dust or other fiber waste will return to the knitting components, and waste collection means (60) for receiving and collecting dust and other fiber waste removed from the double knitting machine (10).

Description: This invention relates to the removal and collection of dust and other waste from the components of circular knitting machines and, more particularly, to the removal thereof from double knitting machines. The operation of circular knitting machines, particularly the yarn feeding, yarn guiding and knitting components thereof, generates considerable dust, lint and other waste. The generation of such waste is particularly acute when cotton yarns are being knitted. Furthermore, knitting machines are now being operated at ever increasing speeds which exacerbate the waste generation problem. Unless removed, such dust or other waste will collect on the various machine components and on the yarns and knitted fabric. Invariably, such waste will adversely affect machine operation and knit fabric quality. Previously proposed dust and other waste removal systems, such as fans or air blowers above the knitting machines and exhaust ducts into which operators direct collected waste, have been unsuccessful in solving the waste problem in knitting machines. The dust removal and collection systems disclosed in commonly owned US-A-5 177 985, 5 363 676 and 5 323 509 have proven to improve greatly the dust removal as well as the collection thereof on circular knitting machines of the single knit type having needles only in the cylinder of the knitting machine. Double knitting machines have needles in the cylinder and needles in a dial cooperating with the cylinder needles for producing a double knit fabric. Such double knitting machines have particular dust and waste generation problems that are distinct from other circular knitting machines. GB-A-1 160 660 describes apparatus for removing fiber waste from a double knitting machine, in which nozzles in the neighbourhood of and below the knitting positions of the machine direct jets of compressed air upwardly at the knitting positions, and an air extractor unit mounted opposite and above the nozzles receives the jets of air from the nozzles and cooperates with the nozzles in forming an air curtain. The air extracting unit comprises an air extracting dish having a restricted air passageway for receiving the jets of air from the nozzles via an ingress end of the passageway located above the knitting positions. The extracting dish is connected by several tubes to an extracting device. It is an object of the present invention to provide a dust and other waste removal and collection system for a double knitting machine which overcomes the disadvantages and deficiencies of prior waste removal systems and effectively removes and collects dust and other waste from the components of a double knitting machine. From one aspect, the invention consists in a double knitting machine having a knitting section comprising a needle cylinder, cylinder needles mounted in the needle cylinder, a dial mounted above and in operative association with the needle cylinder, and dial needles mounted in the dial and cooperating with the cylinder needles, yarn feeding and guiding means for supplying yarns to the cylinder and dial needles to produce double knit fabric, and a dust and other fibre waste removal system comprising means for producing an upwardly flowing air stream through the knitting section and hood means overlying the knitting section and defining a restricted air passageway for receiving the upwardly flowing air stream via an ingress end of the air passageway located above the knitting section, characterised in that the air passageway in the hood means has an upper outlet end above the knitting section and communicating with suction fan means for producing the upwardly flowing air stream, the hood means extends radially outwardly beyond the periphery of the knitting section and the ingress end of the air passageway is located radially outwardly, as well as above, the knitting section so that the air stream created by said suction fan means flows upwardly from and outwardly of said knitting section, whereby dust and other fiber waste is removed from said knitting section and is carried outwardly beyond the periphery of said knitting section. In a preferred embodiment, a circularly movable fan or other air blowing means moves around the knitting machine blowing air inwardly across the yarn feeding and guiding means to assist the suction fan in removing dust and other waste therefrom. A waste collection system may communicate with the suction fan to receive the air stream and entrained waste from the suction fan and to separate the waste from the air stream. From another aspect, the invention consists in a fiber waste removal system for a double knitting machine having a knitting section including a needle cylinder and a dial, and yarn feeding and guiding means, comprising means for producing an upwardly flowing air stream through the knitting section, and hood means operatively associated with the means for producing the upwardly flowing air stream and defining a restricted air passageway therethrough for receiving the upwardly flowing air stream, said hood means being adapted to overlie the knitting section with an ingress end of the air passageway located above the knitting section, characterised in that the air passageway in the hood means has an upper outlet end opposite its ingress end communicating with suction fan means for producing the upwardly flowing air stream, said outlet end being positioned above the knitting section, and said hood means having an internal area greater than the area of the knitting section such that said hood means extends beyond the periphery of the knitting section, said ingress end of said air passageway being in the outer portion of said hood means such that said ingress end is located radially outwardly of and above the outer periphery of the knitting section so that the upwardly flowing air stream produced by said suction fan means flows upwardly from and radially outwardly beyond the knitting section into the ingress end of said air passageway and therethrough to said suction fan means. From yet another aspect, the invention consists in a method of removing dust and other fiber waste from a double knitting machine including a knitting section having a needle cylinder and a dial, and yarn feeding and guiding means, comprising producing an upwardly flowing air stream through the knitting section, and removing the air stream and entrained fiber waste via hood means overlying the knitting section and having a restricted air passageway with an ingress end disposed above the knitting section, characterised by the steps of applying suction to an upper outlet end of the air passageway in the hood means and disposed above the knitting section to produce said upwardly flowing air stream, and directing the upwardly flowing air stream to the ingress end of the air passageway also radially outwardly beyond the periphery of the knitting section so as to move the entrained fiber waste outwardly, as well as upwardly, of the knitting section. In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, in which:- Figure 1 is an elevational view of a double knitting machine incorporating the dust and waste removal and collection system of the present invention; Figure 2 is a top plan view of the knitting machine shown in Figure 1; Figure 3 is an enlarged, fragmentary vertical sectional view taken substantially along line 3-3 in Figure 2; and Figure 4 is an enlarged fragmentary perspective view of a peripheral portion of the air stream confining hood of the dust and other waste removal and collection system of this invention. Referring now more specifically to the drawing, there is illustrated therein a double knitting machine 10 having a knitting section 12 that extends upwardly from a bed 14 which in turn is supported by a plurality of frame members or legs 16 . As is well known, the knitting section 12 of the double knitting machine 10 includes a needle cylinder 18 and a needle dial 20 . Needle cylinder 18 has cylinder needles (not shown) vertically slidable in a multiplicity of needle grooves formed in the outer periphery of needle cylinder 18 . On the other hand, dial 20 has dial needles (also not shown) radially slidable in a multiplicity of needle grooves in the dial 20 . The cylinder 18 and dial 20 rotate at a synchronized speed by a drive means (not shown) with which the double knitting machine 10 is conventionally equipped. During such rotation, the knitting section 12 is supplied with yarns from a creel (not shown) by yarn feeding and guiding means 22 in a manner that is well known. The knitting section 12 and yarn feeding and guiding means 22 generate dust and other fiber waste during operation thereof. In accordance with the present invention, such dust and other fiber waste is removed by a fiber waste removal and collection system, generally indicated at 24 , which partially overlies the knitting section 12 . System 24 includes a suction fan 26 confined within a housing 28 which is open at the bottom thereof. Fan 26 is driven by a motor 29 to create an air stream flowing upwardly through and across knitting section 12 including the cylinder 18 and dial 20 and an air stream flowing inwardly across the yarn feeding and guiding means 22 . System 24 further includes an air stream confining or suction hood 30 which overlies the knitting section 12 and is supported from bed 14 by secondary frame members 32 . Hood 30 includes a generally cylindrical section 34 which is of a diameter generally consistent with the diameter of the bed 14 such that the hood 30 overlies and surrounds the knitting section 12 to capture and confine substantially all of the upwardly flowing air stream and waste entrained therein. Hood 30 further includes a frusto-conical section 36 which extends upwardly and inwardly from cylindrical section 34 to a position immediately below but spaced from the open bottom of housing 28 of suction fan 26 . Frusto-conical section 36 has an outlet opening 38 at its upper terminus such that the interior of hood 30 communicates with fan 26 . Suction hood 30 also includes a second, internal frusto-conical section or member 40 which is solid and is spaced inwardly of frusto-conical section 36 to define a restricted circumferential air passageway 42 through hood 30 . Because the suction hood 30 is of greater diameter than the knitting section 12 and because of the presence of the member 40 therein, the upwardly flowing air stream passing across the knitting section 12 moves radially outwardly thereacross and carries all entrained dust and other fiber waste upwardly and outwardly beyond the periphery of knitting section 12 before the air stream and entrained fiber waste passes into the air passageway 42 . While not required in some instances, it is preferred that a door or movable extension 44 be provided between the lower end of cylindrical section 34 and the top of the bed 14 (as seen in Figure 3) to enclose completely the knitting section 12 . The door or movable extension 44 should be constructed to have movable panels or sections to provide access to the knitting section 12 as needed for proper operation thereof. As illustrated, hood 30 is polygonal in plan and is formed of twelve (12) interconnected sections. However, hood 30 may be of any suitable construction and configuration, such as cylindrical. Provision must also be made for the support of the yarn feeding and guiding means 22 . As illustrated in Figures 1 and 4, support brackets 46 are mounted on a head part 48 of knitting machine 10 and extend upwardly and outwardly therefrom. Brackets 46 pass through openings 49 in frusto-conical section 36 of hood 30 to the yarn feeding and guiding means 22 . While not shown, hood 30 must also be provided with suitable access openings between yarn feeding and guiding means 22 and the knitting section 12 . The location and configuration of such access openings will depend upon the particular yarn feeding and guiding means 22 with which knitting machine 10 is equipped and will be well within the skill of knitting technicians. To assist suction fan 26 in the removal of fiber waste from knitting section 12 , it is preferred that an air jet 50 be provided within hood 30 for blasting air against the knitting components of needle cylinder 18 and dial 20 . A mounting and drive mechanism 52 for air jet 50 is carried by head part 48 (Figure 3). The air jet 50 and its mounting and drive mechanism 52 are more particularly and specifically described in commonly owned US-A-4,703,632, disclosing a speed reduction system imparting rotation to air ejection pipes to rotate the same in the same direction as the rotary needle cylinder. Similarly, a pair of traveling blowers or fans 54 , 56 are mounted outwardly of the yarn feeding and guiding means 22 for blowing relatively high velocity air streams inwardly across the yarn feeding and guiding means. These high velocity air streams assist suction fan 26 in removing fiber waste from the yarn feeding and guiding means 22 and in conveying such waste into fan housing 28 . Blowers or fans comparable to blowers 54 , 56 and the mounting and driving means therefor are specifically disclosed in the commonly owned US-A-5,177,985. Once the dust and other fiber waste has been removed and entrained in the moving air streams created by suction fan 26 , assisted by air jet 50 and blowers 54 , 56 , a duct 58 is connected at one end to the discharge end of suction fan housing 28 and at its other end to a dust and other fiber waste collection means 60 . Duct 58 is preferably formed of sheet metal and waste collection means 60 is formed of a foraminous material to permit air to escape therethrough while entrapping and collecting the dust and fiber waste in collection means 60 . Duct 58 and waste collection means 60 are more specifically disclosed in the commonly owned US-A-5 363 676. In operation, the double knitting machine 10 produces double knit cloth by knitting yarns on the cylinder needles and the dial needles. The yarns are supplied to the cylinder and dial needles by the yarn feeding and guiding means 22 . Considerable dust and other fiber waste is generated by the knitting section 12 and by the yarn feeding and guiding means 22 . The dust and other fiber waste removal and collection system 24 removes and collects such dust and other fiber waste in an improved and highly efficient manner. The dust and other fiber waste is removed from knitting section 12 by the suction fan 26 assisted by the air jet 50 . Because the air passageway 42 within hood 30 is positioned radially outwardly of knitting section 12 , the upwardly flowing air stream created by suction fan 26 flows outwardly beyond the periphery of knitting section 12 , thereby carrying the entrained dust and other fiber waste not only upwardly from but outwardly of the knitting components of the knitting section 12 . Therefore, if any of the fiber waste drops out of the air stream, it will not fall back onto the knitting section 12 . Also, the surrounding relationship of hood 30 to the knitting section 12, particularly if the door or extension 44 is utilized, confines the air stream's outward travel and obviates the need for curtains or other partitions between adjacent knitting machines. The frusto-conical shape of hood 30 confines and deflects the upwardly flowing air stream directly into suction fan housing 28 and past suction fan 26 . An inwardly flowing air stream is created by suction fan 26 assisted by blowers 54, 56 . This inwardly flowing air stream removes dust and other fiber waste from the yarn feeding and guiding means 22 and other associated machine components. Because the yarn feeding and guiding means 22 are located radially outwardly of the knitting section 12 , the inwardly moving air stream takes the entrained dust and other fiber waste away from these knitting machine components. The hood 30 protects the knitting section 12 from any dust or other fiber waste that may drop from the inwardly flowing air stream. The inwardly flowing air stream enters the open bottom of suction fan housing 28 between such housing and the hood 30 and merges with the upwardly flowing air stream from the hood 30 . The merged air streams then pass through the duct 58 and into the waste collection means 60. The air escapes from the waste collection means 60 but the dust and other fiber waste is entrapped therein and collected for subsequent disposal.

Claims: A double knitting machine (10) having a knitting section (12) comprising a needle cylinder (18), cylinder needles mounted in the needle cylinder, a dial (20) mounted above and in operative association with the needle cylinder, and dial needles mounted in the dial and cooperating with the cylinder needles, yarn feeding and guiding means (22) for supplying yarns to the cylinder and dial needles to produce double knit fabric, and a dust and other fibre waste removal system (24) comprising means (26) for producing an upwardly flowing air stream through the knitting section and hood means (30) overlying the knitting section and defining a restricted air passageway (42) for receiving the upwardly flowing air stream via an ingress end of the air passageway located above the knitting section, characterised in that the air passageway (42) in the hood means (30) has an upper outlet end (38) above the knitting section (12) and communicating with suction fan means (26) mounted above said knitting section for producing the upwardly flowing air stream, the hood means extends radially outwardly beyond the periphery of the knitting section and the ingress end of the air passageway (42) is located radially outwardly, as well as above, the knitting section so that the air stream created by said suction fan means (26) flows upwardly from and outwardly of said knitting section, whereby dust and other fiber waste is removed from said knitting section and is carried outwardly beyond the periphery of said knitting sedtion. A double knitting machine according to claim 1, wherein the hood means (30) extends in surrounding spaced relation to the knitting section (12) to confine the upwardly and outwardly flowing air stream to the immediate vicinity of the knitting section and to direct the air stream into the ingress end of said air passageway (42). A double knitting machine according to claim 2, wherein the hood means (30) has access means (44) adjacent the knitting section (12) to provide operator access to said knitting section. A double knitting machine according to claim 1, 2 or 3, including air jet means (50) operatively associated with the knitting section (12) for blasting said knitting section with an air stream to assist the suction fan means (26) in removing dust and other fiber waste from said knitting section. A double knitting machine according to claim 4, including means (52) for mounting the air jet means (50) for movement circumferentially around the knitting section (12), and drive means for moving said air jet means. A double knitting machine according to any preceding claim, wherein the suction fan means is located radially inwardly of the yarn feeding and guiding means (22) and produces a second air stream flowing inwardly across said yarn feeding and guiding means for removing dust and other fiber waste therefrom. A double knitting machine according to claim 6, including blower means (54,56) located radially outwardly of the yarn feeding and guiding means (22) for blowing air inwardly across said yarn feeding and guiding means to assist the suction fan means (26) in removing dust and other fiber waste therefrom. A double knitting machine according to any preceding claim, wherein the hood means (30) comprises an outer hood having a frusto-conical section (36) defining the upper portion thereof and a generally circumferential section (34) depending from the outer periphery of said frusto-conical section, said frusto-conical section having an outlet opening (38) in the upper end thereof immediately below and in operative communication with the suction fan means (26), said circumferential section (34) being spaced radially outwardly of the periphery of said knitting section (12), and an inner hood member (40) located within but spaced from said outer hood member (30) and defining with said outer hood member the restricted air passageway (42). A double knitting machine according to claim 8, wherein the inner hood member (40) is at least partially frusto-conical. A double knitting machine according to claim 8 or 9, wherein the hood means (30) includes an extension (44) projecting downwardly from the circumferential section (34) of the outer hood member into surrounding relation to the knitting section (12). A double knitting machine according to claim 10, wherein said extension (44) has access means therein providing operator access to said knitting section. A double knitting machine according to any preceding claim, including waste collection means (60) connected to the exhaust side of said suction fan means (26) for receiving the air stream and entrained fiber waste from said suction fan means for collecting the waste therein. A fiber waste removal system for a double knitting machine (10) having a knitting section (12) including a needle cylinder (18) and a dial (20), and yarn feeding and guiding means (22), comprising means (26) for producing an upwardly flowing air stream through the knitting section, and hood means (30) operatively associated with the means for producing the upwardly flowing air stream and defining a restricted air passageway (42) therethrough for receiving the upwardly flowing air stream, said hood means being adapted to overlie the knitting section with an ingress end of the air passageway located above the knitting section, characterised in that the air passageway (42) in the hood means (30) has an upper outlet end (38) opposite its ingress end communicating with suction fan means (26) for producing the upwardly flowing air stream, said outlet end being positioned above the knitting section (12), and said hood means having an internal area greater than the area of the knitting section such that said hood means extends beyond the periphery of the knitting section, said ingress end of said air passageway being in the outer portion of said hood means such that said ingress end is located radially outwardly of and above the outer periphery of the knitting section so that the upwardly flowing air stream produced by said suction fan means flows upwardly from and radially outwardly beyond the knitting section into the ingress end of said air passageway and therethrough to said suction fan means. A fiber waste removal system according to claim 13, including waste collection means (60) connected to the suction fan means (26) for receiving the air stream and entrained waste from said suction fan means for collecting the waste removed from the double knitting machine. A fiber waste removal and collection system according to claim 13 or 14, wherein the hood means (30) extends downwardly from and outwardly of said ingress end to confine the upwardly and outwardly flowing air stream with said hood means. A fiber waste removal system according to claim 13, 14 or 15, wherein the hood means (30) comprises an outer hood member having a frusto-conical section (36) defining the upper portion thereof and a generally circumferential section (34) depending from the outer periphery of said frusto-conical section, said frusto-conical section having an outlet opening (38) in the end thereof opposite said ingress end and disposed immediately below said suction fan means (26), and an inner hood member (40) mounted within said outer hood member in spaced relation thereto to define therewith the restricted air passageway (42). A fiber waste removal and collection system according to claim 16, including an extension (44) carried by said circumferential section (34) and extending downwardly therefrom for surrounding the knitting section (12) of the double knitting machine. A method of removing dust and other fiber waste from a double knitting machine (10) including a knitting section (12) having a needle cylinder (18) and a dial (20), and yarn feeding and guiding means (22), comprising producing an upwardly flowing air stream through the knitting section (12), and removing the air stream and entrained fiber waste via hood means (30) overlying the knitting section and having a restricted air passageway (42) with an ingress end disposed above the knitting section, characterised by the steps of applying suction to an upper outlet end (38) of the air passageway (42) in the hood means (30) and disposed above the knitting section (12) to produce said upwardly flowing air stream, and directing the upwardly flowing air stream to the ingress end of the air passageway also radially outwardly beyond the periphery of the knitting section (12) so as to move the entrained fiber waste outwardly, as well as upwardly, of the knitting section. A method according to claim 18, including confining the upwardly and outwardly flowing air stream to the vicinity of the knitting section (12). A method according to claim 18 or 19, including blasting the knitting section (12) with an air jet to assist in removing fiber waste from the knitting section. A method according to claim 20, including moving the air jet circumferentially around the knitting section (12). A method according to claim 18, 19, 20 or 21, including utilising the suction applied to the air passageway (42) in the hood means also to produce a second air stream flowing radially inwardly across the yarn feeding and guiding means (22) for removing fiber waste therefrom. A method according to claim 22, including blowing air inwardly across the yarn feeding and guiding means (22) to assist the suction in removing the fiber waste therefrom.

Inventors: IGARASHI YOSHIAKI, IGARASHI, YOSHIAKI
Applicants: PRECISION FUKUHARA WORKS LTD, PRECISION FUKUHARA WORKS, LTD
Application year: 1993
Main classification: D04B35
IPC codes: D04B35