US 3221683 A
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Description (OCR text may contain errors)
Dec. 7, 1965 c. B ABELSMA 3,221,633
PRESSURE SENSITIVE STREAK ELIMINATOR FOR TUFTING MACHINES 2 Sheets-Sheet 1 Filed Aug. 19, 1965 INVENTOR CORNELIS a. ABELSMA C. B. ABELSMA PRESSURE SENSITIVE STREAK ELIMINATOR Dec. 7, 1965 FOR TUFTING MACHINES Filed Aug. 19, 1963 2 Sheets-Sheet 2 INVENTOR CORNELIS B. ABELSMA United States Patent Office 3,221,683 Patented Dec. 7, 1965 3,221,683 PRESSURE SENSITIVE STREAK ELIMINATOR FOR TUFTING MACHINES Cornelis B. Abelsma, Buena Vista, Va., assignor to James Lees and Sons Company, Bridgeport, Pa., a corporation of Delaware Filed Aug. 19, 1963, Ser. No. 302,888 2 Claims. (Cl. 11279) This invention relates to tufting machinery for producing tufted pile fabrics of the type used as floor coverings. More particularly, the invention pertains to the use of a device for detecting tension in a running yarn end which exceeds a predetermined value in the area between the creel and the needles of a tufting machine.
Machines for producing tufted pile fabric customarily employ anywhere from one to fifteen hundred needles mounted for vertical reciprocation in a needle bar. These needles insert pile yarns through a moving backing sheet in such a way that the yarns carried by the needles may be engaged by oscillating loopers underneath the backing sheet to produce cut and/or uncut pile projections. In certain instances it is desirable to utilize what is known as a pattern attachment, these may take one of several forms, but a well-known type of such pattern attachment employs a plurality of pairs of rollers which are selectively driven at different speeds in accordance with a programming device. The yarn ends fed from a creel are carried over and under selected pairs of rollers so that the rate of feed and/ or the tension introduced into these yarn ends by the pattern attachment may be utilized to controlthe pile height of the various ends. This produces what is known as a patterned or sculptured effect in the pile of the fabric.
In running certain types of yarn and particularly a bulked continuous filament yarn such as nylon, it has been found that especial care must be given to the tension developed in the yarn between the tufting machine and the creel. For large equipment such as a fifteen foot tufting machine the yarn ends are carried from the creel to the pattern attachment through a series of tubes which may be anywhere from fifteen to thirty or forty feet in length. Sometimes these tubes collect lint or other material with which the yarn may be finished to such an extent that the friction of the yarns in the tubes reaches such a degree that the yarn ends break. A more prevalent condition caused by excessive tension in one or two yarn ends produces a phenomenon known as tension streaks. This simply means that all of the pile projections formed by a particular yarn end are lower than r the pattern requires with a result that when the fabric is placed on the floor this row of low pile projections shows up as a discernible streak thus causing a defect. Due to the fact that some synthetic fibers and especially r nylon are very tough and have a relatively high breaking strength, a broken end causing the operator to stop'the machine does not ordinarily occur until after the above described streaky condition has continued for some time. The tufting machine operator cannot'see the fabric being tufted without walking around the end of the machine to the back at frequent intervals. This is not always ractical. Therefore, a tension streak is not always easy to detect during the actual tufting of the fabric so that the tufting machine attendant cannot make a correction until many yards of fabric have been produced and sometimes this is not even noticeable until the fabric is finally unrolled on the inspection floor. A still further complication arises out of the fact that bulked yarn inherently has more stretch and ability to contract after stretching than does wool for example. This ability of nylon to elongate without rupture but to recover its original length after a substantial lapse of time is well known and is described in US. Patent 2,407,634 to Richard C. du Pont.
The above factors indicate the importance of providing an extremely sensitive tension detector in a tufting machine which has the ability to detect tensions in excess of those normally required to pull the various yarn ends through the tubes under conditions in which the internal friction of the tubes varies over wide ranges and thus to avoid excessive tension causing tension streaks or even yarn breakage. Obviously such a device cannot be located between the pattern attachment and the needles since the pattern attachment itself causes wide tension variations which result in a controlled location of the high and low pile as distinguished from a defect due to a series of low pile projections in one or two ends run ning lengthwise in the fabric.
The present invention therefore has for its primary object the provision of a sensitive tension detector positioned on a tufting machine immediately in advance of the pattern attachment and between the pattern attachment and the creel tubes.
A further object of the invention is to provide a tension streak detector ina tufting machine which can be accurately adjusted to detect tensions on the order of a few grams in excess of a predetermined value.
A further object of the invention is to provide a sensitive tension detector for tufting machines or the like which can be operated up to a predetermined value with wide fluctuations but which when the machine is operating will knock off the machine after the predetermined value has been exceeded for a timed interval.
Further objects will be apparent from the specification and drawings in which FIG. 1 is a transverse schematic section through a multi-needle tufting machine and a six roll pattern attachment, showing the tension streak detector in normal operation,
FIG. 2 is an enlarged detail showing the tension streak detector of FIG. 1 as seen from the opposite end,
FIG. 3 is an enlarged fragmentary detail of one of the pivoting arms of the detector positioned in normal operation,
FIG. 4 is a view similar to FIG. 3 with the tension detector actuated to stop the tufting machine,
FIG. 5 is an enlarged detail as seen at 55 of FIG. 2, and
FIG. 6 is a wiring diagram for the tension detectors.
The invention comprises the provision of -a series of pivoting bell crank elements or rocker arms positioned between the pattern attachment and the discharge end of the creel tubes. The pivoting arms carry individual yarn ends and are located in a position to deflect the yarn ends substantially from a straight line path between two stationary yarn guides. Each of the crank elements is positioned to close an electrical contact if it is pivoted more than a predetermined amount. A time delay relay is utilized -to prevent accidental stopping of the tufting machine and also to enable the detectors to reach a state of equili'brium when the machine is started.
Referring more particularly to the drawings, a conventionai broad or yardage tufting machine comprises a bed 20 over which a backing fabric or sheet F is fed from a pin feed roll 21 by means of a pin feed take-up roll 22. Rolls 23 and 24 cooperate with rolls 21 and 22 to maintain fabric contact therewith. As the fabric F passes over the throat or bed 20 of the tufting machine a series of pile yarns Y are carried through the fabric by means of needles 25, 25 mounted in needle bar 26. The needle bar 26 is journaled in sleeves 27 and is reciprocated vertically by means of a crankshaft 28 having eccentric driven cranks 29 and connecting rods 30. The latter elements are mounted in the upper tufting machine housing 35 which is supported by pedestal 36 and provided with a stationary yarn guide 37 as well as a presser foot assembly 38. The needle bar 26 also carries the conventional jerker bar 39 and a series of loopers 40, 48 mounted on looper rockshaft 41 reciprocate through a suitable arc to engage the yarn in the needles. All of the above structure is conventional and needs no further detailed description. The pattern attachment shown in FIG. 1 is intended to exemplify any type of such attachment which controls the yarn feed. In a six roll (six pairs) pattern attachment, one sixth of the yarn ends is carried over the top pair of feed rollers 45 and additional sixths of the yarn ends are carried over the other pairs 46, 47, 48, 49, and 50. Before passing over each pair of rolls the yarn ends Y are carried through stationary yarn guides 55, 56, 57,58, 59, and 60.
Immediately above the upper yarn guide 55 I provide a structural frame element 65 which carries a series of pivoting rocker arms 66 and 67. The upper series of arms 66, 66 (FIG. is journaled on a shaft 68 whereas the lower series of arms 67, 67 is journaled on a shaft 69. These shafts are secured in the frame 65. Each of the individual yarn ends Y is fed through an eye 70 in the foot 71 of each of the pivoting rocker arm-s. Directly in advance of the tension detector assembly the yarn ends pass through a stationary yarn guide 75 and the location of the eyes 70 is such that the included angle made by the yarns between guides 55 and 75 is approximately 120. The yarn ends are drawn from a creel 76 through the creel tubes 77, 77 in accordance with conventional practice.
A series of pressure sensitive rubber tubes 80, 80 is secured to a plate 81 which is in turn mounted on the frame member 65 by means of bolts 82, 82. The tubes 80, 80' carry pairs of electrodes or strip contacts 83 and 84 within the bore of the tube 80 so that when the tube is collapsed contact is made between electrodes 83 and 84 to complete an electrical circuit stopping the tufting machine. The internal pressure in tube 80 is so controlled that they are extremely sensitive and may be utilized to detect pressure differentials on the order of a few grams. The construction and arrangement of tubes 80 is identical to that described above in connect-ion with tubes 80 and the corresponding electrodes 83' and 84' are utilized to close a circuit to stop the machine as will be described more fully hereinafter. The number of tube sections 80 and 80 which are utilized on any particular machine will depend upon the width of the machine, but it has been found that sections on the order I of to 18 inches are satisfactory. In order to obtain variations in the pressure required to collapse the tubes I provide a series of apertures 85, 85 in which the bar 81 may be selectively mounted thus giving variation in distance from the fulcrurns 68, 69 of each of the pivoting arms.
Referring now to FIGURE 6 a tube section having upper and lower pairs of tubes 80 has electrodes 83, 83 thereof connected in parallel to one side of the main power line 90 through lead 91. The opposite electrodes 84, 84 are connected in parallel in such a way that an indicating light 92 is utilized to tell the operator which tube section has been actuated. This enables the creel attendant to promptly remedy the high tension condition. The use of relatively short tube sections facilitates locating a faulty end or ends. When the contacts 83, 84 in any tube are closed, relay R2 is energized to open a circuit to the main tufting machine motor 94 which is tied to the other side of the main line 93. Leads 95 and 96 are connected to electrodes 84, 84 and thence through the armature of relay R2 and the indicating light 92. Upon the energization of relay R2 normally closed contacts R211 are opened so that relay R3 is de-energized thus opening the normally closed cont acts R3a of relay R3 in the main motor circuit. Any other tube section operates in exactly the same Way and I have illustrated a typical second section with primed numbers. In 11118 case contact between electrodes 83 and 84' energizes relay R1 through lines 91', or 96'. At the same time the indicating light 92' lights up so that the operator can tell the particular tube section that has stopped the tufting machine. Energization of relay R1 opens normally closed contacts Rla of relay R1 which are connected in series with the contacts R2a of relay R2. It will be understood that the same circuitry shown in FIGURE 6 can be utilized for any desired number of tube sections in the tufting machine and this number may be dependent upon the ease with which an operator can detect the location of a tight end.
Time delay relay R3 serves an important function in preventing accidental stopping of the machine which may be caused momentarily by slubs or accidental contact of one of the yarn ends by an operator. Also, the delay feature is of importance in starting up the machine since there will be some inertia and friction in the eyes 70 sufficient to close the contacts 83, 83 and 84, 84 until normal operating conditions are achieved. It has been found in practice that a five second delay is adequate for the above purpose.
It will thus be understood that I have produced an extremely sensitive and satisfactory tension streak detector which may be effectively used to prevent undesired tension streaks in a tufted fabric. The device is very effective in eliminating a most vexing problem incident to the high speed tufting of bulked continuous filament synthetic yarn.
Having thus described my invention, I claim:
1. In pile fabric tufting apparatus having a creel, a plurality of needles reciprocable to penetrate a backing material fed to the needles, a series of yarn guides for directing yarn ends to said needles, a motor for operating said needles, and means including creel tubes for feeding yarn ends from the creel to the needles, the improvement which comprises first stationary yarn guides mounted adjacent the discharge ends of the creel tubes, second stationary yarn guides mounted in spaced relation to said first yarn guides, pivoting yarn contacting elements journaled between said two stationary yarn guides, said elements having yarn contacting surfaces offset from the straight line path between the stationary yarn guides at one end thereof to normally engage and deflect the travelling yarn ends from said straight line path, pivot means for mounting said elements, electrical switch actuating means carried by the other end of said elements, electrical switch means operable directly by the pivoting of each of said elements, electrical connections between said switch means and the motor whereby the circuit to the motor is opened when the yarn contacting means pivots to a predetermined position to thereby shut off said motor when excessive tension is present in a feeding yarn, and time delay means to prevent opening of the circuit to the motor until a predetermined interval has elapsed after one of the elements has pivoted due to excessive tension in a feeding yarn.
2. Apparatus in accordance with claim 1 in which the electrical switch means comprises a resilient tube extending along a plurality of the switch actuating means and a series of electrical contacts contained in said tube.
References Cited by the Examiner UNITED STATES PATENTS 1,877,647 9/1932 Crawford 66161 2,448,615 9/1948 Mosley 307141.4 X 2,569,442 10/1951 Anderson ZOO-61.18 X 2,791,820 5/1957 Spencer 66163 2,862,465 12/1958 Card 11279.6 3,094,855 6/1963 Vossen 11279 X 3,103,755 9/1963 Hajos 38-143 JORDAN FRANKLIN, Primary Examiner.