US2427406A

US2427406A - Detector for locating imperfections in knitted fabrics

Info

Publication number: US2427406A
Application number: US588364A
Authority: US
Inventors: George E Henning
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1945-04-14
Filing date: 1945-04-14
Publication date: 1947-09-16
Anticipated expiration: 1964-09-16

Description

Sept. 16, 1947. G. E. HE NNINGV 2,427,406

DETECTOR FOR LOCATING IMPERFECTIONS IN KNITTED FABRICS Filed April 14, 1945 2 SheetEs-Sheet 1 //v VENTOR 6. E. HENN/NG ATTORAEY p cs. E. HEINNING 2,427,406

DETECTOR FOR LOCATING IMPERFEGTIONS IN KNITTED FABRICS Filed April 14, 1945v 2 She ts-Sheet z 22 '22 23/ 1 2a 28 I MIim w, 27 23 f i\ W '26 w 26 v \2 g 4/ 43 Q 1% FIG. 5

A TTORNE V Patented Sept. 16 1947 UNITED STATES PATENT OFFICE DETECTOR FOR LOCATING IMPERFEC- TIONS IN KNITTED FABRICS Application April 14, 1945, Serial N 0. 588,364

12 Claims. 1

This invention relates to detectors for locatin imperfections in knitted fabrics, and has for its object the provision of new and improved detectors for this purpose.

.In the operation of known machines for knitting a plurality of textile strands into a fabric upon a conductor, such a knitting machine sometimes operates imperfectly and forms an imperfect fabric upon a conductor advanced therethrough. In order to adjust or repair the knitting machine and to minimize the length of the imperfect portion of the fabric, the imperfect portion of the fabric should be detected as soon as possible after it is formed.

A detector forming one embodiment of the invention, which is designed to be associated with a knitting machine, for locating-imperfections in knitted fabrics, includes an apertured member having a. plurality of fingers formed thereon so as to rest on a knitted fabric on a covered conductor passing through the apertured member after the fabric has been knitted thereon, said fingers serving to engage imperfections in a knitted fabric as the fabric i moved therealong, whereby the apertured member is carried with the fabric to cause a suitable mechanism to stop the knitting machine promptly.

A complete understanding of the invention may be obtained from the following detailed description of detectors forming embodiments thereof, when read in conjunction with the appended drawing, in which Fig. 1 is a fragmentary, partially sectional, side View of a knitting machine and a detector embodying the invention;

Fig. 2 is an enlarged fragmentary, vertical section of a portion of the detector;

Fig, 3 is an enlarged fragmentary, vertical section of a portion of the detector;

Fig. 4 is an enlarged, horizontal section taken along line 4-4 of Fig. 3;

Fig. '5 is an enlarged, vertical section taken along line 55 of Fig. 3;

Fig. 6 is an enlarged, fragmentary, vertical section of a portion of a detector forming an alter native embodiment of the invention, and

Fig. '7 is an enlarged, fragmentary, vertical section taken along line 'l-! of Fig, 6.

Referring now in detail to the drawing, there is shown a portion of a knitting machine Ill (Fig. 1), of the type shown in co-pending application, Serial No. 551,336, filed August 26, 1944, by D. G. Scrantom for Detector and automatic stop device for textile machines. This knitting machine includes a knitting head ll having a p1urality of knitting needles l2 for knitting a plurality of feeder threads 15 into a single-stitch tubular fabric l6 upon an insulated tinselv conductor I! to form a fabric-covered conductor l8 as the conductor 11 is advanced through the knitting head. The knitting machine includes a web holder 20 having a bore 2| therein through which the fabric-covered conductor I8 i advanced from the knitting head.

A detector 23 forming one embodiment of the invention is shown in Figs. 1 to 4, inclusive, and includes an actuating tube 22 having a collar 25 secured thereon and designed to extend into the bore 2! of the web holder 20 with the collar 25 resting upon the web holder. A bushing 26 having a shoulder 21 formed thereon (Figs. 2 and 3) is secured to a reduced portion 28 of the actuating tube 22 by pins (not shown), and serves to receive and hold frictionally a pair of semicylindrical bushings 3E! and 3|, which are provided with

semicylindrical bores

32 and 33, respectively.

The semicylindrical bushing 30 has an elongated finger 35 projecting therefrom and the bushing 31 has two

elongated fingers

36 and 31 projecting therefrom. Since the

bushings

30 and 3| are made of spring steel and shanks 34 of the

fingers

35, 36 and 3'! are thin, the fingers are very resilient. The

fingers

35, 3E and 31, which are of equal lengths, taper to points 38 and are provided with contacting surfaces 39, which extend to the points 38.

The normal positions of the

fingers

35, 33 and 31 are such that the elongated contacting surfaces 39 lay upon equally spaced points of a circle Whose diameter is slightly smaller than that of the fabric-covered conductonand the longitudinal axes of the contacting surfaces are parallel when the fingers are in such positions. When the semicylindrical bushings are positioned over the fabric-covered conductor l8 and are assembled in the bushing 26, the fabric-covered conductor forces the fingers slightly apart so that heel portions 40 thereof engage the conductor and the points 38 are spaced slightly outwardly from the fabric l6, as illustrated by the point 38 when in the position shown in full lines in Fig. 5. This prevents the points 38 (Fi 4) from engaging unobjectionable deviations in the fabric It as it is carried therepast.

The bushing 39 has a pair of notches 4! (Figs. 3 and 4) formed therein and the bushing 3! is provided with apair of tongues 43 complementary to the notches M. The tongues 43 are designed to fit into the notches M and prevent relative longitudinal movement between the semicylindrical bushings 3S and 3! V A compression spring 42 (Fig. 1) and an annular collar 45 are positioned between the actuating tube 22 and a latch 43. As the knitting operation proceeds, the fabric-covered conductor I8 is advanced upwardly, as viewed in Fig. 1, through the semicylindrical bushings 30 and Si, the actuating tube 22, the compression spring d2, the collar 45 and a slot 41 formed in the latch Q6. The latch 45 is pivotally mounted upon a bracket 58 and is provided with a notch designed to engage a roller 52 mounted on levers 35. The levers 55 are secured by a bolt 56 to the bracket 55! for pivotal movement with respect thereto and are urged in a clockwise direction, as viewed in Fig. 1, by a tension spring 51 secured to a pin (iii connecting the levers 55 and to a bracket 6 I.

The latch 36, when in the positionshown in full lines in Fig. 1, serves to engage theroller 52 and hold the roller 52 in the position shown in full lines in Fig. 1, in which position the roller 52 engages a spring-pressed button 36 of a microswitch fil The microswitch (ii is connected by conductors W to control means (not shown) of the knitting machine I9, which control means are identical with the control means disclosed in the above-mentioned application, Serial No. 551,- 336. When the spring-pressed button 66 is engaged by the roller 52, the microswitch 6? permits the knitting machine to operate, but when the button is not engaged by the roller 52, the microswitch serves to stop the knitting machine through the control means.

In the operation of the detector 23, the knitting head II serves to knit the feeder threads I5 into the tubular fabric IE, which is drawn on the conductor I"! as the fabric and the conductor I! are drawn upwardly at a predetermined rate of speed from the knitting head II, through the web holder 23. The fabric-covered conductor I3 is advanced through the

semicylindrical bushings

30 and 3|, the actuating tube 22, the compression spring 42, the annular collar 45,, and the slot 47 and then engages a power-driven capstan of suitable design (not shown) which draws the fabric-covered conductor through the knitting machine and through all the above-mentioned elements. At this time, the latch 16 is in a posi tion in which it holds the roller 52 in a position engaging the spring-pressed button 36 of the microswitch 31, whereby the microswitch 6'! permits the knitting machine Iii to operate.

When the knitting head II operates perfectly,

it knits the feeder threads I5 into the fabric I3, which includes thin portions II (Figs. 2 and 3) alternating with ridge portions I2 formed of the interlocking portions of the feeder threads. The thin portions It and ridge portions '82 extend along the fabric I3 in parallel relationships with respect to each other and with respect to the longitudinal axis of the conductor IT. The

fingers

35, 36 and 3'; are spaced around the fabric It in such positions that the contacting surfaces 39 thereof slidably engage the thin portions ii of the fabric it between the ridge portions 12 with the points 38 on the fingers spaced slightly outwardly from the fabric.

When one of the needles breaks, which sometimes occurs, the fabric I5 is formed imperfectly and wavy ridge portions 75 (Fig. 3) and humps 19 (Fig. 5) are formed in the fabric. The points 38 engage the wavy ridge portions 75 or the humps "I9 as the fabric-covered conductor I8 is advanced upwardly, and are carried upwardly thereby, whereupon the bushings 33 and SI, the actuating tube 22, the compression spring 42, and the collar G5 are drawn upwardly with the fabric I6. This causes the latch 33 to be moved to the position shown in dotted lines in Fig. l, in which position the notch in the latch iii is out of engagement with the roller 52 and the roller 52 is moved away from the spring-pressed button 36 by the levers 55 and the tension spring 51. When the roller 52 is moved away from the springpressed button 66, the microswitch til causes the knitting machine if! to be stopped.

An operator then adjusts or repairs the knitting machine It and resets the latch 36 and the micros-witch 61, after disengaging the

fingers

35, 35 and 3? from the fabric I6 and sliding the actuating tube 22, the compression spring 42, the collar t5 and the bushings 3i! and SI downwardly upon the fabric I 6 to the positions in which they are shown in Fig. 1. The knitting machine Ill then may be restarted and, as long as the fabric It has no imperfections therein, can be operated.

Sometimes the needles I2 (Fig. 1) operate imperfectly in such a manner that a helical ridge portion l8 (Fig. 2) is formed in the fabric It. When this occurs the helical ridge portion T8 is advanced to one of the points 38 on the

fingers

35, 33 and 37, that point engages the helical ridge portion and the operation of the knitting machine it is stopped in the same manner as that described hereinabove.

The

fingers

35, 36 and 31 of the

bushings

30 and 3| serve to ride on the thin portions II of the fabric I6 without positively engaging the fabric It as long as no imperfections occur in the fabric It. The compression spring 42, and the taperedness and the resiliency of the fingers 35, 3B and 3'! prevent the actuation of the latch 43 and stopping of the machine by slight variations in the fabric-covered conductor I8. Also, the

bushings

30 and 3| may rotate in the bushing 26, which rotation permits the

fingers

35, 33 and 31 to float between the ridge portions 12 of the fabric I6. However, when imperfections such as the wavy ridge portions I5 (Fig. 3) and humps I9 (Fig. 5) or the helical ridge portion 18 (Fig. 2) are formed in the fabric I6 and are advanced to the points 38 of the fingers, the points engage the wavy ridge portions, the humps I9 or the helical ridge portion and cause the knitting machine to stop. Thus, the knitting machine In is stopped before long lengths of imperfect fabric are formed and the knitting machine can be put into operative condition without the waste of large quantities of fabric knitted thereby and the expense of repairing or replacing long lengths of fabric.

A detector I23 forming an alternative embodiment of the invention is disclosed in Figs. 6 and 7. This detector includes a bushing I26, which is identical with the bushing 26 and which is secured to the lower end of a compression spring I42. The bushing I26 serves to frictionally hold therein semicylindrical bushings I30 and I3! of spring steel, which are provided with semicylindrical bores I32 and I33, respectively. The bushing 1,353 is provided with a finger I35, and the bushing I3! is provided with fingers I36 and I31.

The fingers I35, I33 and I3? taper to points I38 and are provided with elongated contacting surfaces I39. The fingers I35, I36 and I3! are all of different lengths and have thin shanks I34. The prong is longer than either of the prongs I36 and I31 and has an elongated contactin "shoulder I29 forming a continuation of the contacting surface I39 thereof, and the contacting shoulder contacts ridge portions such as straight ridge portions I12 of a fabric II 6 to hold the bushings I30 and I3I in equilibriumon the fabric, as the fabric, which covers an insulated conductor M1 to form a fabric-covered conductor H8, is advanced through the bushings. Ex- 'cept for their difierences in lengths and-the shoulder I29, the fingers I35, I36 and I31 are identical with the

fingers

35, 36 and 31. A pair of tongues illustrated by a tongue I43 (Fig. '1) are provided on the semicylindrical bushing I30 and are designed to project into notches, such as the notch I4I, formed in the semicylindrical bushing I3I to hold the bushings I30 and I3I against longitudinal movement therebetween.

The bushing I26 serves to hold the semicylindrical bushings I30 and I3I in positions around the fabric II6 knitted upon the conductor II1 by a knitting head (not shown) identical with the knitting head II, with the fingers I35, I36 and I31 thereof pressed against the fabric H6. The fingers I35, I36 and I31 are of such difierent lengths that, when the semicylindrical bushings I30 and I3I are assembled, the points I38 at the ends thereof lay upon points of a helix, which helix is the same as that along which a helical ridge portion I18 of the fabric H6 is sometimes formed by imperfect operation of the knitting machine with which the bushings I30 and I 3I are associated. Normally this knitting machine forms straight thin portions I1I of the fabric II 6 alternating with the straight ridge portions I12 thereof, and heel portions I40 of the contacting surfaces I39 ride on the thin portions I1I between the straight ridge portions I12. When the knitting machine knits continuous imperfections into the fabric II6, such as the continuous helical ridge portion I18 of loosely knitted loops, all of the points I38 positively and simultaneously engage the helical ridge portion ,I18 as'it is advanced thereto and are drawn upupon the knitting machine can be adjusted to operate correctly. The points I38 also serve to engage imperfections such as the wavy ridge portions (Fig. 3) and humps 19 (Fig. 5), when such imperfections occur, and stop the knitting machine associated therewith. The resiliency imparted to the fingers I35, I36 and I 31 by the thin shanks I34 causes the heel portions I40 of the contacting surfaces I39 to remain at all times in close contact with the fabric IIB, while the taperedness of the fingers I35, I36 and I31 and the outwardly spaced points I 38 together with the action of the compression spring I42 permit unobjectionable deviations in the fabric-covered conductor II8 to be advanced therepast witharound a conductor to form a covered conductor which is advanced therethrough, a bushing having a plurality of resilient fingers projecting therefrom in positions spaced around a covered conductor as it is advanced through the bushing, said fingers tapering to points and also being provided with contacting surfaces and being arranged so that the contacting surfaces normally touch a circle whose diameter is less than that of the covered conductor, whereby the fingers are spread outwardly when in engagement with the covered conductor and the points thereof do not engage'perfect portions of the cover but do engage imperfect portions thereof.

2. In a detector for use with a knitting machin including a knitting head fo knitting a plurality of strands into a fabric upon an insulated conductor to form a fabric-covered conductor as the insulated conductor is advanced therethrough in a predetermined direction, a detector for locating imperfections in a fabric knitted on an insulated conductor by the knitting head, which comprises a tubular member having a plurality of resilient fingers projecting therefrom in parallel relationship, means for positioning the tubular member around a fabric-covered conductor in a position in which the resilient fingers rest on the fabric of the conductor at equally spaced points thereon and point in a direction opposite to that in which the fabric-covered conductor is advanced through the knitting head.

3. For use with a knitting machine including a knitting head for knitting a plurality of strands into a tubular covering upon an insulated conductor to form a fabric-covered conductor as the insulated conductor is advanced therethro gh, means for stopping the knitting machine, and a pivotally mounted lever for actuating the stopping means, a detector locating imperfections in a tubular covering of a fabric-covered conductor formed by the knitting machine, which comprises a split bushing having a plurality of fingers pro vided with tapered points and positioned over the tubular covering, said fingers being of such different lengths that the tapered points thereof lay on a helix and being designed to slide upon the tubular covering as the fabric-covered conductor is advanced relative to the bushing with the tapered points spaced slightly from perfect portions of the tubular coverin but laying in the path of imperfections thereof, and a spring for connecting the split bushing to the lever, whereby the lever is pivoted by the bushing when one of the fingers engages an imperfection in the fabric and the knitting machine is stopped.

4. For use in a knitting machine including a knitting head for knitting a plurality of strands into single-stitch fabric around a conductor to form a fabric-covered conductor as the conductor is advanced therethrough, said fabric including raised ridge portions extending along the conductor in parallel relationships therewith and thin portions extending along the conductor in parallel relationships therewith, and means for stopping the knitting machine, a detector for 10- cating imperfections in the fabric of a fabricccvered conductor formed by the knitting machine, which comprises a bushing having a plurality of tapered fingers projecting therefrom and positioned around the fabric, said fingers being spaced around the fabric so as to rest upon the thin portions of the fabric, and means for connecting the bushing operatively to the stopping means, whereby the bushin actuates the stopping means when one of the fingers engages an imperfection in the fabric.

5, For use in a knitting machine including a knitting head for knitting over a conductor as the conductor is advanced therethrough a plurality of strands into single-stitch fabric to form a fabric-covered conductor, said fabric including -ridge portions extending along the conductor in posite to that in which the fabric is advanced and to lay on points of a helix, and a compression spring for connecting the bushing operatively to the stopping means, whereby the bushing actuates the stopping means when one of the points of the fingers engages an imperfection in the fabric.

6. For use in a knitting machine including a knitting head for knitting upon a conductor as the conductor is advanced therethrough a plurality of strands into a fabric to form a fabriccovered conductor and means for stopping the knitting machine, a detector for locating imperfection in the fabric of a fabric-covered conductor formed by the knitting machine, which comprises a plurality of resilient fingers having surfaces formed thereon for engaging slidably the fabric, said fabric-engaging surfaces tapering to points and laying normally upon a circle whose diameter is less than that of the fabricoovered conductor, and means serving to mount the fingers in positions in which the fingers are spaced around the fabric with the fabric-engaging surfaces thereof in contact with the fabric in floating relationships therewith and to connect operatively the fingers and the stopping means, whereby the stopping means is actuated when one of the points of th fingers engages an imperfection in the fabric.

'7. For use in a knitting machine including a knitting head for knitting a plurality of strands upon a conductor as the conductor is advanced therethrough to form a fabric-covered conductor and means for stopping knitting machine, a detector for locating imperfections in the fabric of a fabric-covered conductor formed by the knitting machine, which comprises a tubular member having a plurality of resilient fingers which are of different lengths and which have surfaces formed thereon for engaging slidably a fabric knitted upon a conductor by the knitting head and also provided with points spaced slightly from the fabric, said fingers projecting from the tubular member in positions in which they are spaced around the fabric with the points thereof being positioned on points of a helix, and a compression spring for connecting the tubular member and the stopping means, whereby the stopping means is actuated when one of the points of the fingers engages an imperfection in the fabric, the longest of said fingers also being provided with a shoulder for engaging the fabric to hold the tubular member in equilibrium upon the fabric.

8. For use in a knitting machine including a knitting head for knitting upon a conductor as the conductor is advanced therethrough a fabric to form a fabric-covered conductor and means for stopping .the knitting machine, a detector for locating imperfections in a fabric of a fabriccovered conductor formed by the knitting head, which comprises a tubular member for surrounding the fabric-covered conductor as the fabriccovered conductor is advanced from the knitting head, a plurality of resilient fingers projecting from the tubular member in directions parallel with the axis of the fabric-covered conductor, said fingers having points formed at the extremities thereof and also being provided with fabric-engaging surfaces adjacent to the points serving to hold the points away from fabric normally but to permit the points to engage imperfections in the fabric to cause the tubular member to be carried along with the advancing fabric-covered conductor, and means operatively associated with the tubular member for actuating the stopping means when the tubular member has been advanced a predetermined distance.

9. For use in a knitting machine including a knitting head for knitting upon a conductor as the conductor is advanced therethrough a fabric to form a fabric-covered conductor and means for stopping the knitting machine, a detector for locating imperfections in a fabric knitted by the knitting head upon a conductor, which comprises a split tubular member, a bushing for mounting the split tubular member rotatably therein in a position in which it surrounds the fabric-covered conductor as it is advanced from the knitting head, a plurality of resilient fingers having points at the extremities thereof projecting from the tubular member in directions parallel with the axis of the fabric-covered conductor, said fingers also being provided with fabric-engaging surfaces extending to the points and being sprung outwardly by the fabric-covered conductor so that the points formed at the extremities thereof do not engage perfect portions of the fabric but engage imperfections in the fabric and cause the tubular member and the bushing to be carried along with the advancing fabric-covered conductor, and a compression spring connected to the bushing for actuating the stopping means when the tubular member and the bushing have been carried a predetermined distance.

10. For use in a knitting machine including a knitting head for knitting upon a conductor as the conductor is advanced therethrough a fabric having ridge portions and thin portions extending along the fabric parallel with the conductor to form a fabric-covered conductor and a microswitch for stopping the knitting machine when actuated, a detector for detecting imperfections in such a, fabric, which comprises a plurality of elongated fingers, a bushing for mounting the fingers in a ring-like fashion around a fabriccovered conductor in positions in which the fingers rest on the thin portions of the fabric,

whereby smooth portions of the fabric slide past the fingers but roughened portions of the fabric are engaged by the fingers and move the fingers and the bushing therewith as the fabric-covered conductor is advanced, and a spring for connecting the bushing operatively with the microswitch to actuate the microswitch when the fingers engage a roughened portion of the fabric.

11. For use in a knitting machine including a knitting head having a plurality of needles for knitting upon a conductor as the conductor is advanced therethrough a plurality of strands into a fabric to form a fabric-covered conductor, said fabric having ridge portions extending therealong in positions parallel with the conductor and thin portions positioned between the ridge portions, means for stopping the knitting machine when actuated, a detector for locating imperfections in the fabric, which comprises a split tubular member having pointed resilient fingers projecting therefrom, a bushing for mounting the split tubular member rotatably therein, and a compression spring serving to connect the bushing operatively to the stopping means and to mount the bushing and the split tubular member in positions in which they surround the fabric-covered conductor, said fingers having surfaces formed thereon for pressing against the thin portions of the fabric with the points of the fingers spaced outwardly from the fabric-covered conductor, said surfaces being shorter than the distances between humpy portions of the fabric occurring when one of the needles breaks, whereby the points of the fingers engage the humps in the fabric as the fabric-covered conductor is advanced therepast and cause the compression spring to actuate the stopping means when the fingers have been carried a predetermined distance with the fabric-covered conductor.

12. For use in a knitting machine including a knitting head for knitting a plurality of strands into a fabric, means for advancing fabric formed by the knitting head in a predetermined direc- 10 tion from the knitting head as the fabric is formed and means for stopping the knitting machine, a detector for locating imperfections in the fabric comprising a plurality of elongated resilient fingers having points and heels formed thereon, means for holding the fingers in parallel positions in which the heels on the fingers are pressed against the fabric to hold the points on the fingers slightly away from perfect portions of the fabric but in the path of any imperfection occurring in the fabric, means for mounting the fingers for lateral floating movement with the fabric, and means for connecting operatively the fingers and the means for stopping the knitting machine so that the latter means is actuated when the point on one of the fingers engages an imperfection in the fabric.

GEORGE E. HENNING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,190,169 Bardsley Feb. 13, 1940 2,368,686 Sperzel Feb. 6, 1945