Dust sucking and discharging device for fiber wastes on knitting machine

Fiber waste generated adjacent the knitting section and the yarn feeding members of the machine is conducted by air streams into the lower end of a first duct extending upwardly from the knitting section. The air and therein entrained fiber waste passes from the upper end of the duct and then sequentially through a laterally extending second duct and a vertically extending third duct to a waste collection box. The third duct is made of flexible fabric, vinyl or similar material having therein a multiplicity of small openings that permit lateral passage of air from the duct, while restricting lateral passage of fiber waste from the duct. A funnel-shaped member within the collection box compacts the waste entering the box. The first duct has vertically aligned sections that are telescopically adjustable.

Some of the subject matter of the subject application is also disclosed in 
commonly owned U.S. patent application Ser. No. 07/940,512, filed Sep. 4, 
1992, and also in commonly owned U.S. patent application Ser. No. 
07/869,460, filed Apr. 16, 1992. 
FIELD OF THE INVENTION 
This invention relates to an apparatus for collecting and removing lint, 
dust and similar fiber waste from components of a circular knitting 
machine, such as the yarn carrier, sinker, sinker cap, and needle 
components, and from yarn feeding and/or guiding components associated 
with the knitting machine. 
BACKGROUND OF THE INVENTION 
Over 100 yarn supply bobbins may be associated with a conventional circular 
knitting machine. Particularly when the yarn being knitted includes cotton 
fiber, the fiber waste generated by engagement of the yarn with the 
machine's yarn feeding, guiding and/or knitting components is quite 
substantial. The fiber waste problem is aggravated by the fact that 
knitting machines are being operated at increasingly faster speeds, which 
increases the rate and amount of fiber waste generation. 
After fiber waste has become airborne, it may settle upon the yarn feeding 
and guiding devices or other components of the knitting section of the 
knitting machine where the fiber waste was generated, or upon one or more 
neighboring machines. This increases the possibility of yarn breakage, 
defective stitch formation, and general degradation of the quality of the 
knitted fabric. 
Previously proposed apparatuses for removing fiber waste from circular 
knitting machines have employed fans or air blowers located above the 
machines. However, these merely displace the fiber waste from one location 
to another and do not collect it since fiber waste cannot be efficiently 
collected by merely subjecting it to a blast of air generated by a fan, 
blower or the like. It has also been proposed to enclose each of the 
knitting machines in a curtain-like sheet, and to provide adjacent each 
machine an exhaust duct into which a machine operator may introduce fiber 
waste generated by the machine and collected by the operator. Providing 
separate exhaust ducts in association with each of the knitting machines 
is quite expensive, however. Additionally, the curtain-like sheets limit 
access to the knitting machines, and rapidly become unsanitary due to 
adherence of lint, oil, dirt and the like to them. 
SUMMARY OF THE INVENTION 
The apparatus of the present invention includes a vertically extending 
first duct that closely overlies and extends upwardly from the knitting 
section of the knitting machine, and that has upper and lower sections 
that are capable of telescopic adjustive movement relative to each other. 
Motor driven fans produce air streams that entrain fiber waste generated 
adjacent the knitting section of the machine and/or adjacent the periphery 
of the machine. The air streams and therein entrained fiber waste pass 
into the lower end of the first duct, upwardly through it, and then from 
the duct's upper end. The air streams and entrained waste passing from the 
first duct are received within the upstream end of a second duct that 
conducts the air streams and waste laterally outwardly from the center of 
the machine and then to and from the duct's downstream end, which is 
preferably located outwardly from the periphery of the knitting machine. 
The air stream and entrained fiber waste passing from the downstream end 
of the second duct enters the upper end of a third, generally vertically 
extending duct having a lower end releasably connected to a fiber waste 
collection box. In contrast to the first and second ducts, which may be 
and usually are formed of metal or other non-porous and relative 
inflexible material, the third duct is preferably formed of flexible 
fabric or vinyl material having perforations or other small openings that 
permit lateral passage of air, while restricting lateral passage of fiber 
waste, from the second duct. Air and fiber waste passing from the lower 
end of the third duct enter the waste collection box via a funnel-shaped 
member that compacts the waste. 
In a preferred embodiment of the invention, the first duct includes an 
upper section, and a lower section that mates with and is vertically and 
telescopically movable relative to the upper section so as to adjust the 
magnitude and/or velocity of the air streams passing through the duct.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 of the drawings shows a circular knitting machine 10 having a 
knitting section 12 that extends upwardly from a bed 14. As is well known 
to those skilled in the art, lint, dust and similar fiber waste is 
generated during operation of machine be. In accordance with the present 
invention, such fiber waste is collected and conducted from machine be by 
apparatus 16 associated with machine 10. Apparatus 16 includes a duct 18 
that is mounted above and in axial alignment with knitting section 12 of 
machine be. Duct 18 includes an upper section be' that is fixedly 
connected to and supported by frame members 20 of machine 10. Duct 18 
further includes a coaxial lower section 18" that resiliently mates with 
and is telescopically adjustable relative to upper section be'. The lower 
end portion of lower duct section 18" has an outwardly flared skirt 22. A 
motor driven fan 24 is mounted within upper section 18' of duct 18. 
Referring now also to FIGS. 2-10, as well as FIG. 1, apparatus 16 further 
includes an endless rotatable ring 26 that is supported in outwardly 
spaced adjacent relationship to the upper part of machine 10 by support 
members 28 that extend radially outwardly from upper frame members 20 of 
machine 10. A pair of motor driven fans 32 are fixedly connected to ring 
26, at diametrically opposed locations thereon, for bi-directional 
movement with the ring between their solid line and phantom line positions 
shown in FIG. 2. The aforesaid rotational movement is imparted to ring 26 
by drive means best shown in FIGS. 7-10. Such drive means includes a drive 
motor 34 mounted upon a support plate 36 extending downwardly from at 
least one support member 28. A drive roll 38 upon the output shaft of 
motor 34 supportively underlies ring 26 and, upon actuation of motor 34, 
imparts rotational movement to the ring 26. A guide roll 40 upon plate 36 
engages the upper edge of ring 26. A cam plate 42 mounted for longitudinal 
sliding movement upon and relative to plate 36 is displaced between its 
positions shown in FIGS. 8A and 8B when engaged by a cam element 44 
secured to and projecting upwardly from ring 26. Movement of cam plate 42 
by cam element 44 varies the position of the cam follower 46 of a limit 
switch 48, which in turn causes reversal of the direction of rotation of 
drive roll 38 and, thus, of ring 26 and the fans 32 secured to the ring. 
Electrical power is conducted to each of the fans 32 and at least one motor 
34 by wiring within a conduit 50 that is connected at its inner end to a 
rotatable member 52 projecting upwardly from the center of the upper 
framework of machine 10. The outer section of each conduit 50 extends 
vertically downwardly and includes a flexible suction 50'. 
As is best shown in FIGS. 5, 6 and 8, each fan 32 is connected to its 
associated support member 28 by a tubular bracket 54 that receives a 
vertical shaft 56 that may be moved (upon release of a set screw or other 
locking element 57) vertically so that its air outlet opening 58 is at an 
elevation adjacent that of yarn feeding members 60 proximate the 
downstream ends of pipes 62 that conduct yarn from a creel (not shown) to 
machine 10. Consequently, when fans 32 are energized and travel around the 
periphery of machine 10, streams of air pass from the fans to the yarn 
feeding members 60. As is indicated by the directional arrows in FIG. 1, 
the air streams from fans 32 entrain fiber waste generated at the members 
60 and conduct such waste to a location adjacent the flared open lower end 
of duct 18. An upwardly directed air stream generated by the fan 24 within 
duct 18 then conducts the entrained waste removed from the yarn feeding 
members, along with the fiber waste removed from the knitting section of 
machine 10, upwardly to and through the upper end of duct 18. The quantity 
and velocity of the fiber waste entraining air stream passing upwardly to 
and through duct 18 may be varied by adjusting the vertical position of 
lower duct section 18'. Although the blade component of fan 24 
illustratively is located within upper section 18' of duct 18, the fan 
might instead be mounted anywhere along the length of duct 18, or even at 
a location below the lower end of the duct. 
The air and entrained fiber waste passing upwardly from the upper end of 
duct 18 is received within a laterally extending second duct 64 having a 
downstream end spaced radially outwardly from machine 10. A vertically 
extending third duct 66 has its upper end releasably connected, as by 
means of a band 65, to the downstream end of duct 64. In contrast to ducts 
18 and 64, which customarily are formed of sheet metal or similar 
relatively stiff imperforate material, duct 66 is formed of flexible and 
durable cloth or vinyl material having a multiplicity of small openings 
therein. The number of openings in the material of duct 66 is preferably 
within the range of approximately 100-120 per square inch, and more 
preferably is approximately 110 per square inch. The size of the openings 
is such as to permit lateral egress of air from duct 66, while preventing 
or at least minimizing lateral passage of fiber waste from the duct. 
The downstream end of duct 66 communicates with and is releasably 
connected, as by a band 68, to the upper end of a fiber waste collection 
box 70 located in laterally spaced relationship to machine 10, as shown in 
FIG. 1. The bands 65, 68 may be elastic, or of the type having cooperating 
hook and loop members, or of some other type. The front, rear and opposite 
side walls of box 70 illustratively and preferably have panels of 
perforate material that is the same as or similar to the material of duct 
66, and that functions in the same manner to permit lateral egress of air, 
but not fiber waste, from the box. The fiber waste entering the open upper 
end of box 70 passes downwardly through a funnel-shaped member 72, best 
shown in FIG. 4, adjacent the upper end of the box. Passage of the fiber 
waste along the downwardly and inwardly sloping surfaces of member 72 and 
through its central opening 74 compacts the fiber waste, which facilitates 
its subsequent removal from the box 70. 
If the fiber waste passing through duct 66 should tend to adhere to the 
interior surfaces of the duct, it may be easily dislodged by shaking or 
"patting" the duct. 
Although duct 66 and waste collection box 70 illustratively are both of 
square cross-sectional shape, they may be of circular or other 
cross-sectional shape. 
While specific embodiments of the invention have been shown and described, 
this was for purposes of illustration only, and not for purposes of 
limitation, the scope of the invention being in accordance with the 
following claims.