US3438188A

US3438188A - Yarn defect detecting device

Info

Publication number: US3438188A
Application number: US585912A
Authority: US
Inventors: Beryl A Boggs
Original assignee: Allied Chemical Corp
Current assignee: Honeywell International Inc
Priority date: 1966-10-11
Filing date: 1966-10-11
Publication date: 1969-04-15
Anticipated expiration: 1986-04-15

Description

April 15, 1969 B. A. 80665 YARN DEFECT DETECTING DEVICE Sheet of Filed Oct. 11, 1966 FIG.3.

swQcwseo 'INVENTOR Beryl A. Boggs April 15, 1969 s. A. BOGGS 3,438,188

} YARN DEFECT DETECTING DEVICE Filed Oct. 11, 1966 Sheet 3 of 2 INVENTOR Beryl A. 80995 BY/d50475 W IYWTORNEY United States Fatent 3,438,188 YARN DEFEQT DETECTING DEVICE Beryl A. Boggs, Chester, Va., assignor to Allied Chemical Corporation, New York, N.Y., a corporation of New York Filed Oct. 11, 1966, Ser. No. 585,912 Int. Cl. D01h 13/16 US. CI. 57-31 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to new and useful improvements in devices for detecting yarn breaks or irregularities in runing yarn primarily in the textile processing field. More specifically, this invention, as illustrated herein, relates to an electrical switch-actuating device of wide utility in the textile industry, but is especially useful with textile spinning machines.

Various devices for detecting yarn or thread breaks or irregularities therein, either with or without corresponding stop motion devices, are well known in the art. In processing yarn from one textile machine position to another, it has been found highly desirable to be able to quickly ascertain the presence of a break or serious loss of tension due to defective variations or irregularities in the yarn. Such ascertainment or detection has been accomplished by various means and forms of complex detecting mechanisms. In general, these detecting devices contained mechanical or electrical means for actuating a machine stopmotion device, or signalling the need for corrective action other than actually stop-ping the particular textile processing machine. The yarn contacting elements of many of these devices have been of the gravity operated or dropwire type, and those of the adjustable flywire type, wherein said fiywire is held under spring tension against the yarn and operates a switch in a stop-motion device or signal circuit upon breakage or excessive reduction in the tension of the running yarn.

While most of these devices generally have overcome a number of the operating problems related to initial tension adjustment, centrifugal force, changing thread weight, and high speed of response to thread breaks, they have not, however, provided means for discriminating between undesirable loss of thread tension or breakage and the condition where there is a momentary but non-significant loss of tension in the running line. It has been found that the latter condition, for example, occurs frequently in the flywire type detecting devices where the machine stopping or signalling function is triggered by electrical actuating means. The electrical actuating means in many of these devices are highly sensitive to minute motions such as those caused by high frequency impulses. Thus, these devices cause frequent undesirable machine stoppage or false signalling. Moreover, the devices known heretofore have not shown how to discriminate between and, hence, regulate or respond to the varying impulse amplitudes and durations.

Thus, it has been found in accordance with this invention that many of the above-mentioned problems can be avoided by utilizing the yarn detecting device more particularly described hereinbelow. The yarn detecting device of this invention is capable of continuously monitoring a ice running strand and can be removed from operating position and returned without affecting adjustment of the sensing mechanism. In addition, the instant device is capable of locking the sensing element in an off position and may be provided with an optional attachment for detecting slubs or flaws in the yarn. In a draw-twisting machine, for example, yarn is drawn from a creel package at a metered rate by a feed roll. The yarn makes several turns around a draw roll, around a draw pin, across a heater, several turns around a second draw roll rotating about four times as fast as the first draw roll and through a pigtail guide, a ring traveler and finally onto a package. During this process, the yarn is stretched and twisted. Thus, without the use of the detecting device of this invention, any breakage of a running strand would result in the yarn being wound onto the draw or feed rolls. Since these machines contain multiple spindles with a common drive without means for disengaging the rolls from said driving means, the wraps on the draw or feed rolls must be removed by the operator while they are still turning which is an undesirable operation. Thus, in its broadest aspects, the apparatus of this invention comprises a feeler-arm which senses variation in a running yarn and upon sensing such change, moves to activate a microswitch and to release a cutter which severs the yarn at the supply creel. In addition, a signal light or some other suitable signalling device may be actuated to indicate to the operator that an end is down.

Accordingly, it is an object of this invention to provide a device for the continuous monitoring of a running strand, e.g. yarn, and for stopping the yarn feed at the creel to eliminate wraps.

It is another object of this invention to provide an improved yarn-breakage detector that will discriminate between desirable and undesirable reductions of thread tension by suitable adjustment of the feeler-arm bias means, increasing its sensitivity with a decrease in said bias, and thus prevent any false signalling or unnecessary machine stoppages.

It is another object of this invention to provide a sensing feeler-arm having an adjustable biasing spring means of simple construction and easily operated to change the bias in accordance with the particular type of yarn being used, providing a corresponding change in sensitivity.

It is still another object of this invention to provide a spring-clip means for latching the feeler-arm in o position out of the way of a re-stringing operation following a stoppage of the yarn, and until said yarn is running again without causing actuation of the stop or signal switch.

It is still a further object of this invention to mount the feeler-arm on a vertical pivot to provide an adjustable bias independent of gravity, and thus provide a steady sensing response of the feeler-arm throughout its range of operation unaffected by the unbalanced masses on opposite sides of said vertical pivot.

It is still a further object of this invention to provide a vertical pivot for the feeler-arm mount whereby this mount on which a guide is also mounted to extend under the feeler-arm, may be turned to move the feeler-arm and guide out of the way of a dofling of the yarn package.

It is still a further object of this invention to provide a retractable slub catcher, which may be mounted to extend from the side of the feeler-arm mount, above the feelerarm and a guide leading to the'bobbin or winder to prevent any defective thread or yard portions from being inadvertently wound on the bobbin or other package being These and other more specific objects of the invention will become apparent from the following and more detailed description of the invention, as illustrated in the accompanying drawings, wherein:

FIGURE 1 is a perspective view of the sensing device mounted on a draw-twister machine,

FIGURE 2 is an enlarged sectional view of the sensing device including the feeler-arm mount and its vertical hinge mounting,

FIGURE 3 is a plan view of this sensing device,

FIGURE 4 is a sectional plan view taken on the line 4-4 of FIGURE 2, with the feeler-arm released to a switch closed position,

FIGURE 5 is a similar view with the feeler'arm shown in a latched switch open position,

FIGURE 6 is an elevational front view of the sensing device and its support bracket, hinged on a bearing support,

FIGURE 7 is a similar view partly in section to show some details of the vertical hinge for the sensing device support bracket,

FIGURE 8 is a sectional plan view taken through the hinge on the line 8-8 of FIGURE 7, and

FIGURE 9 is a sectional view through the hinge washer taken on the line 99 of FIGURE 7.

One application of the sensing device of this invention is illustrated in FIGURE 1 as applied to a draw-twister machine. Here, the yarn at each station is threaded from the feeding creel above (not shown) through a yarn cutter 11, around a guide 13, over a cot roll 15, around the top draw roll 17, draw pin 19, over the surface heater 21, around the bottom draw roll 23; past the feeler-arm, through the pigtail guide 14, and a slub catcher on the sensing device down to the pigtail guide leading to the bobbin (not shown) on which the yarn is twisted around.

As shown in the drawings, in accordance with this invention, the present sensing device 10 has a support bracket 12 on which a pigtail guide 14 is mounted, extending to a position in line with a vertical portion of the running yarn 16 just before it reaches a winding device (not shown), e.g., a. bobbin, on the machine on which it is being wound. This support bracket has a microswitch 18 mounted thereon and a feeler-arm 20 having a vertical pivot 22 which is mounted in this support bracket, a cam 24 for actuating the microswitch at a predetermined reduction in yarn tension of the yarn 16 against which the feeler-arm is biased by an adjustable coil spring 26 mounted around the pivot of the arm.

The feeler-arm 20 is biased against the running yarn just above the pigtail guide 14 through which it is threaded. A slotted slub catcher 28 may be mounted on the side of this support bracket and extends to intercept the running yarn by straddling it just above the feeler-arm 20. This slub catcher extension comprises an arm 29 extending from the side of the support bracket 12; and the slub catcher 28 is slidably mounted on this arm for retraction from its yarn straddling position during string-up operations. Any defective enlargement of the yarn will obviously be caught by the slub catcher, thus causing a break in said yarn with subsequent loss of tension therein so that the sensing feeler-arm will move into operative or to the on position 30 to release the microswitch into its normally closed position which, in turn, may be connected to a stop-motion mechanism (not shown) and/ or a signal showing need of attention by the operator to that particular station on the machine.

The coil spring 26 is mounted around the vertical pivot of the feeler-arm and has one end 32 fixed to the support bracket 12 with the other end being adjustably fixed by extension 34. The extension 34 of the spring 26 crosses the axis of the feeler-arm 20 which has an axial slot 36 wherein the screw clamp 38 is slidably mounted for adjusting the position at which said other end of said coil spring is fixed to produce the bias and switch-actuating characteristics desired. The adjustment, of course, will vary for different types of yarn operations, depending on the yarn weight, as well as speed and other tension characteristics of the operation.

Thus, any defective loss of tension in the running yarn,

which may differ in various operations, can be sensed for actuating the microswitch at the desired loss or reduction of tension so that the defective operation can be corrected before resuming. Moreover, while the operation is being corrected to obtain the proper tension in the running yarn, the feeler-arm can be moved out of the way from the biasing side of the yarn by means of latching it in the out-of-the-way or off position 40 on a spring clip 42 extending from the bracket.

The spring retainer clip 42 extends from the support bracket 12 and is adapted to latch the feeler-arm in swung-away off position 40 for proper re-threading or adjustment of the yarn operation before unlatching and returning the feeler-arm to its normally operating position against the running yarn. The microswitch actuating cam 24 has a concentric cam surface within the range of this swing of the feeler-arm so as to maintain the microswitch in the open position. This is the position that it is actuated into by the cam 24 when the feeler-arm 20 is in normally operating position biased against the running yarn. When the yarn tension is reduced sufiiciently or when the yarn breaks, the feeler-arm 20 responds to move the cam 24 out of engagement with the switch arm 44 which then is released into its normally closed switch position, so as to operate any circuit that might be necessary, either for stopping the machine or the particular yarn winders and/ or for operating a signal circuit.

It should be noted that the adjustment of the spring by moving the point at which it is fixed to the feeler-arm further away from the pivot 22 will reduce the tension, as well as increase the sensitivity of the feeler-arm at its "normally operating position because the slot in said feelerarm is extending axially thereof, whereas the end of the spring extends tangentially of the arm pivot so that the end of the spring crosses the axis of the feeler-arm at an acute angle.

The support bracket 12 is mounted hingedly to the frame of the machine by means of a vertical hinge bearing support bracket 46 and has an adjacent bearing surface 48 with a shoulder 50 of this bearing support bracket. These adjacent bearing shoulder surfaces are provided with a spring pressed detent means 52 in the surface 48 for locating the support bracket 12 in normal operating position when the rounded head of the detent means engages the -bore 54 in the shoulder 50 and for releasing it into the off position, swung out of the way of the line of the running yarn, so that dofiing operations may be performed without interference by the extensions on the bracket. This off position of the support bracket 12 is shown in full lines in FIGURE 8, relative to its normal operating position shown in dotted lines. The retracted position of the slub catcher is also shown in dotted lines. An index mark 56 may be placed across the joint between the bearing shoulder surfaces to indicate the normal position of the support bracket 12 on the hinge bearing support bracket 46. Surface 50 and bore 54 may be provided with a washer S7 fixed by rivets 58 to the bearing bracket 46.

Many obvious modifications in the details and arrangement of parts may be made, however, without departing from the true spirit and scope of the invention, as more particularly defined in the appended claims.

What is claimed is:

1. A sensing device for textile machines and the like, comprising:

(a) a support bracket adapted to be mounted on a machine,

(b) a guide extending therefrom positioned in line with a vertical portion of a running strand, (c) a switch means mounted on the support bracket, (d) a strand tension feeler arm having a vertical pivot mounted in said bracket including a cam for actuating the switch means at a predetermined reduction in tension on the strand,

(e) a spring associated with the vertical pivot for biasing the feeler arm against the running strand, and (f) means mounted on said bracket adapted for retaining the feeler arm in swung-away position for rethreading a strand before returning said feeler arm to its normal operating position biased against the running strand.

2. The sensing device of claim 1 in which the cam is comprised of a concentric switch-actuating surface with in the range of said swing of the feeler arm to malntaln the switch means in actuated position.

3. A sensing device for textile machines and the like, comprising:

(a) a support bracket adapted for mounting on a machine, said support bracket being hinged on a vertical hinge bearing having spring pressed detent means between adjacent coplanar bearing shoulder surfaces for releasably retaining said bracket and its guide assembly in normal operating position, said bracket and its extensions being swingable on said'hinge bearing to one side out of said normal operating position, for dotting,

(b) a guide extending from said bracket and positioned in line with a vertical portion of a running strand,

(c) a switch means mounted on the support bracket,

(d) a strand-tension feeler arm having a vertical pivot mounted in said bracket including a cam for actuating the switch means at a predetermined reduction in tension on the strand, and

(e) a spring associated with the vertical pivot for biasing the feeler arm against the running strand.

4. A sensing device for textile machines and the like,

comprising:

(a) a support bracket adapted to be mounted on a machine,

(b) a guide extending therefrom positioned in line with a vertical portion of a running strand,

(0) a switch means mounted on the support bracket,

(e) an adjustable spring associated with the vertical pivot for biasing the feeler arm against the running strand, one end of said spring being fixed to said bracket, the other end being extended tangentially therefrom and adjustably fixed to a slide mounted in a guide slot extending axially in said feeler arm, to respond to the desired reduction in the tension of the running strand against which the feeler arm is biased by said spring, with a corresponding increase in sensitivity for lower tensioned strands.

5. A sensing device for textile spinning machines and the like, comprising:

(a) a support bracket adapted for mounting on a machine,

(b) a guide extendin therefrom to a position in line with'a vertical portion of a running strand just before it reaches a winding device on the machine on which it is being wound,

(c) a switch means mounted in said support bracket,

(d) a strand-tension feeler arm having a vertical pivot mounted in said support bracket and a cam for actuating said switch means at a predetermined reduction in the strand tension,

(e) an adjustable spring mounted around said pivot for biasing the feeler arm against said running strand above said guide, and

(f) a slotted slub catcher extending from said support bracket to straddle said strand, said support bracket being hinged on a vertical hinge bearing having spring pressed detent means between adjacent coplanar bearing shoulder surfaces for releasably retaining said bracket and its guide and slub catcher assembly in normal operating position in line with said running strand.

6. The sensing device of claim 5 in which the slub catcher is slidably mounted for moving it out of its strand straddling position during a string-up operation.

7. A sensing device for continuously monitoring a runing strand, which comprises:

(a) a support bracket rotatably mounted on a machine on a first vertical pivot,

(b) a guide member extending therefrom positioned in line with a vertical portion of the running strand,

(0) a switch means associated with the support bracket,

(d) a strand tension feeler arm mounted for movement on a second vertical pivot in said support bracket,

(e) biasing means for maintaining the feeler arm in contact with the running strand, and

(f) means for actuating the switch means upon the occurrence of a substantial reduction in the tension on said strand.

8. The sensing device of claim 7 in which the means for actuating the switch means is a cam forming a portion of the feeler arm.

9. The sensing device of claim 7 in Which the feeler arm has a slot and a screw clamp slidably mounted in said slot for adjusting the bias imposed. upon the feeler arm.

10. The sensing device of claim 7 in which a retainer means is mounted on said bracket for holding the feeler arm in a swung-away position removed from the normal path of the strand. 0

References Cited UNITED STATES PATENTS 2,467,366 4/1949 Arrowood 66-1 2,904,872 9/ 1959 Kin-gsbury 242-37 2,993,659 7/1961 Johnson 24275.5 X 3,149,394 9/1964 Doyle 28-64 FOREIGN PATENTS 951,118 3/1964 Great Britain.

WILLIAM S. BURDEN, Primary Examiner.

U.S. Cl. X.R.