US2355465A

US2355465A - Device to detect skew in fabrics

Info

Publication number: US2355465A
Application number: US504697A
Authority: US
Inventors: William C Oberkirk
Original assignee: United Merchants and Manuf Inc
Current assignee: United Merchants and Manuf Inc
Priority date: 1943-10-02
Filing date: 1943-10-02
Publication date: 1944-08-08
Anticipated expiration: 1961-08-08

Description

Aug. 8, 1944. w. c. QBERKIRK DEVICE TO DE'I'EOT SKEW IN FABRIC Filed 001;. 2, 1943 R O T N E V m ATTORNE server.

Patented Aug. 8, 1944 DEVICE TO DETECT IN FABRICS William C. Oberkirk, Bronx, N. Y'., assignor to United Merchants & Manufacturers, Inc., Wil mington, DeL, a corporation of Delaware.

Application October 2, 1943, Serial No; 504,697

3 Claims. (01. zc-sn This invention relates to the textile'art and more especially to a device for detecting skew of the weft strands of woven fabrics.

In the art of manufacturing textiles it is common practice to pass the fabric through one or more tenter frames, the purpose of which is well known. As the fabric continuously passes through these frames it is grabbed by the fingers thereof and stretched laterally. This action is apt to throw the weftstrands out of their desired relation perpendicular to the longitudinal axis of the fabric and perpendicular to the warp strands. Means are available and used in the art for the purpose of preventing this distortion or skew. Such means are known and need not be described in detail since they do not form part of the present invention. For purposes of identification, refskew or distortion will be readily apparent. In the absence of distortion the lines of the images corresponding to the weft threads at opposite edges of the fabric will be substantially aligned.

The presence of skew or distortion is indicated by an oifset relation of the lines of the pairs of images.

The principles of the invention will be defined in the'claims and illustrated by the followin de scription taken in conjunction with the accompanying drawing, in which:

Fig. 1 shows diagrammatically a train of fabric treating.apparatusincluding an embodiment of erence may be had to United States Patents- 2,209,220, 2,106,611, 2,106,612, and 2,311,406, which describe certain forms of the devices mentioned. While such devices are useful, they can not be depended upon completely to prevent skew.

It is an object of the present invention to devise I apparatus which will enable skew to be readilydetected. I

The apparatus of the p esent inventionmay be employed in conjunction with the above menthe present invention;

Fig. 2 is an. enlarged diagrammatic sectional view taken on the line 2-2 of Fig, 1; Fig. 3 is a diagrammatic view of apair of images of the weft threads at opposite edges of the fabric when the weftstrands are properly arranged and aligned; and

Fig. 4 is a diagrammatic view showing a pair of images of th weft threads at opposite edges of the fabric when the weft threads are skewed or distorted.

Referring first to Fig. 1, this is essentially a fiow sheet or diagrammatic view showing a typical or specific treatment of fabric involving the use of tenter frames,v in conjunction with which apparatus an embodiment of the invention is diagrammatically indicated at the extreme left, it being understood that this view shows merely one of the many instances in which the invention as disquency, These flashes may be emitted fromagij gaseous dischargelamp by discharging an electric current through the gaseous filling of said lamp at a controlled frequency. The light from each of the illuminated areas may then be prd jected on any suitable viewing means such as a screen, and said light directedfrom said areas so that the pair of images of the weftstrand at opposite sides of said fabric are grouped in closely juxtaposed positions visible to the eye of an ob- By suitably correlating the frequency of the light flashes with the speed of travel of the web or fabric, the images of the weft threads cast upon the screen may appear stationary or moving at such a low rate of speed as to be clearly visible, and by juxtaposing the image of the weft threads "rolls 9. being employed to direct the fabric.

closed and claimed herein may be utilized. The fabric I passes from an accumulation 2 thereof through a mangle 5 provided with treatment rolls 6, in which the fabric may be subjected to treatmentwith any desirable finishing agent, and then to a straightening tenter frame I, suitable guide A skew controlling device indicated generally at I0 may be provided with the object of automatically preventing. skew and enabling the tenter frame to straighten out the weft threads or strands.

The fabric then passes over guide roll I2 and drying cans I4 and then passes, via guide rolls I5, to a finishing tenter frame I'I provided with a hot air drier I8, the tenter frame ll being provided with drive motor I9. The fabric then passes over I guide rolls 20,2 I, 22 and is taken up on accumula tion roll 23. Intermediate the rolls 22 and 23 the inspection and detection device of the present of one edge of the fabric with those of other, any

invention is employed, that device being further shown in Fig. 2. Opposite each of the edges 26 and 21 of the fabric or web I, there are arranged apair of stroboscope lamps 28. Such lamps per se are known and the structure need not be described in detail except to state that they commonly include a transparent envelope containing a rare gas or mixture of gases and provided with electrodes connected to a source of discontinuous electric current, usually alternating, the fre quency of which is controllable by the timer 38, current being delivered to the lamp through leads 3|, 32, and 33. Between the lamps 28 and the edges 26, 21, condensing lens means, indicated generally by 34, are arranged. The lens means 34 concentrates light from the lamp 28 so that a I beam of light is directed transversely of the fabric I through the interstices between the strands at the areas at the edges 26 and 21 thereof. On the other side of the fabric .opposite the lamps 28, means are provided to pickup the transmitted light and project images of the warp and weft threads and direct two pairs of images thus produced so that they are visible to the eye of an observer in closely juxtaposed position. This means may comprise a telescopic apparatus indicated generally as 35. This comprises a tube 31 with projecting lens means indicated generally as 38 at each of the two ends thereof. As shown in Fig. 2, those ends may be continuations of the tube 31, the axes of said ends being transverse to the axis of the tube 31, the axis of which, as specifically shown. in Fig. 2, is perpendicular to the longitudinal axis of the fabric I and substantially parallel to the plane of said fabric. Intermediate the ends of the tube 31 the tube 39 projects therefrom at right angles, at one end of which there is provided a viewing screen 40, The tube 39 may have a wall or diaphragm 4| extending longitudinally thereof and dividing it into substantially two passageways. Reflectors 43 direct the light emitted by the lamps 28 and transmitted through the interstices of the fabric I and through the projection lens means 38 on the screen so that images of the weft and warp strands at the edges 28 and 21 are grouped on-said screen in closely juxtaposed position readily visible to the eye of the observer. Any suitable magnification of the strands may be effected by means of the lens system in a manner which will be clear. At 45, there is diagrammatically shown a telescopic construction to permit focusing adjustment and at 46, a similar construction'to provide lateral adjustment of the tube 36 for focusing purposes and to accommodate different widths of fabric.

In the operation of the device, the operator, knowing the speed of travel of the fabric as it leaves the tenter frame I! on its way to take-up roll 23, adjusts the frequency of the light flashes emitted by the lamps 28 so that the images of the warp and weft threads passed upon the viewing screen 40 either appear stationary or moving at such a low rate of speed as to be clearly visible as a series of lines, as indicated in Figs. 3 and 4. As above mentioned, distortion of the weft threads is indicated by the fact that the lines of the image of the weft threads of the edge 21 are offset in relation to the lines of the image of the weft threads of the edge 26. When such distortion is detectedthen steps may be immediately taken by known means to adjust the operation of the tenter frames to cure this condition.

It is to be understood that the embodiment of the invention-specifically hereinabove described may be modified by those skilled in the art without departing from the principles of the invention as defined in the appended claims. For example, instead of employing light transmitted through the interstices of the fabric, the lamps 28 could be arranged on the same side of the fabric as that in which the telescopic apparatus 36 is positioned, in which case reflected light would be employed to produce images of the strands. It is preferred, however, to employ transmitted light.

I claim:

1. In conjunction with apparatus for finishing woven fabrics including a tenter frame and means to continuously pass the fabric in sheet form from the tenter frame to a place of disposal at a predetermined linear speed, a pair of stroboscopic lamps arranged on one side of said cloth, each of said lampsbeing adjacent an edge of said fabric; means to vary the frequency or the light flashes from said lamp in accordance with the speed of movement of said fabric, said lamps being adapted to direct a seriesof light flashes of controllable frequency transversely of said fabric and through the interstices of the strandsthereof; a tube having an axis substantially parallel to the plane of said fabric and positioned on the other side of said fabric and in adjacent spaced relation thereto; said tube having projection lensmeans I at each end thereof opposite said lamps, image viewing means intermediate the ends and means to direct the projected pair of images of the warp and weft strands of the opposite edge portions of said fabric and to groupsaid pair of images so that they are visible to the eye of an observer in closely juxtaposed position at the viewing means.

2. In conjunction with apparatus for finishing woven fabrics including a tenter frame and means to continuously pass the fabric in sheet form from the tenter frame to a place of disposal at a predetermined linear speed, a pair of stroboscopic lamps arranged on one side of said cloth and to project their beams through limited areas of the fabric spaced apart widthwise thereof; means to vary the frequency of the lightfiashes from said lamp in accordance with the speed of movement of said fabric; a housing positioned on the other side of the fabric from said lamps and in adjacentspaced relation thereto; said housing having projection lens means at each end thereof opposite said lamps, image viewing means intermediate the ends and means to direct the projected pair of images of the warp and weft strands of said spaced apart areas and to group said pair of images so that theyare visible to the eye of an observer in closely juxtaposed position at the viewing means.

3. In conjunction with apparatus for finishing woven fabrics including a tenter frame and means to continuously pass the fabric in sheet form from the tenter frame to a place of disposal at a predetermined linear speed, a pair of stroboscopic lamps arranged on one side of said cloth and to project their beams through limited areas of the fabric spaced apart widthwise thereof means to vary the frequency of the light flashes from said lamp in accordance with the speed of movement of said fabric; means located on the other side of the fabric from said lamps to direct the light from the illuminated areas and to create images of the warp andweft threads of said areas; and means to group said images so as to be visible in closely juxtaposed position.

WILLIAM C. OBERKIRK.