US2701980A - Fabric analyzer - Google Patents

Description

Feb.-15, 1955 v G. A. w. ABBOTT 2,701,980

' FABRIC ANALYZER Filed Oct. 4, 1951 2 Shets-Sheet 1 Feb. 15, 1955 A. w. ABBOTT 2,701,980

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6 76 M oz f 5- -5 @QZW United StatesPatent O FABRIC ANALYZER George A. w. Abbott, Magog, Quebec, Canada Application October 4,1951, Serial No. 249,698 6 Claims. (CI. 88-24) The applicant's development The applicant has now developed a method of analyzing the structure of textile fabrics in which the analysis is highly accurate and with which a permanent record of the analysis is readily available for comparison with a standard.

This method embodies the steps of photographing whe fabric in enlarged silhouette preferably against a calibrated grid. The photograph shows the fabric in detail so that the structural characteristics and defects can easily be observed. The photograph serves as a permanent record of the analysis.

The invention also includes photographing the fabr c during processing. Thus a sub ect portion of the fabric is held in spread out condition in the beam from the light source and the subject portion photographed in silhouette.

An apparatus according to the invention for carry ng out this method includes a photographic apparatus having means for holding a photographic medium, lens and shutter, a support for the fabric including a transparent base preferably provided with a calibrated grid or screen, means for holding fabric against the base, an enclosure passage extending from the base to adjacent the lens, and a light source adjacent the fabric support at the side remote from the lens.

The invention will be more fully understood by reference to the accompanying drawings illustrating a preferred apparatus embodying it and also illustrating analyses made according to the invention.

Referring more particularly to the drawings,

Figure 1 is a perspective view showing the general ar rangement of the preferred photographic apparatus.

Figure 2 is a vertical cross section through the apparatus shown in Figure 1.

Figure 3 is a plan view of the fabric support.

Figure 4 is a detailed fragmentary exploded perspective view showing the way in which the parts of the fabric support are associated.

Figure 5 is a photographic reproduction of an analysis made according to the invention of one type of fabric.

Figure 6 is a photographic reproduction of an analysis made according to the invention of another fabric.

Figure 7 is a view of a transparent graduated measure used in pick counting or measuring the analyses in accordance with the invention.

As seen in the drawings, the preferred apparatus 1ncludes a standard A mounted on legs 15 having casters 16 to permit the apparatus to be moved around. The photographic apparatus B of the invention is mounted on the standard A for vertical adjustment through brackets 20 and 22. These are held to the standard A by T- mernbers 21 and 23 each provided with a thumb nut.

A light source C is mounted on the standard A for vertical movement through a bracket 3% and a T-connection 31.

The apparatus B includes a light-tight body at preferably tapering from square at the large end to square at 2,701,980 Patented Feb. 15, 1955 the small end. At the bottom of the casing 40 is provided means 41 for holding a photographic medium. This may be a single or double plate holder with a spring leaf, as shown, or other suitable arrangement. At the other end of the casing there is a lens 46 and a shutter 45.

A fabric holder D is mounted on the arm 22 as will be described. This is a hood preferably tapering from square at the large end to round at the small end. The holder D includes a lower threaded cylindrical neck 54 which fits a cylindrical threaded collar 51 mounted on an arm 55. A threaded locking ring 52 is provided to lock the neck 54 in position. The arm 55 is pivoted for swivelling by a bolt 57 and nut 58, with a sleeve 56 to the arm 22. Extending upwards from the neck 54, the holder D includes an outwardly flared casing 58 with a square upper edge 59. The inside of the upper edge 59 includes a recess 60. This recess accommodates the edges of a transparent gridded plate 65 and upwardly spaced from this plate a transparent plate 67. The fabric to be analysed goes between the plates 65 and 67. Pivoted catches 69 hold the' glass 67 in place and clamps it over the fabric and plate 65.

A convenient size for the gridded transparent plate is 3 inches square with 1 inch grids. The threaded neck 54 should be at least 1 inch in length and of a diameter about a quarter larger than that of the lens being used. The height of the holder D may thus be adjusted to compensate for the thickness of the fabric when the analyzer is used as a portable unit and the grid plate is raised to press flush with the cloth surface. The pivotal arrangement allows the holder to be swung aside when making adjustments to the lens-shutter.

The brackets must be arranged so as to maintain perfect alignment of the fabric, the lens and the image planes. There is a fixed distance between the fabric, the lens and the photographic medium so as to give exactly the enlargement desired, preferably five times.

The lens with a convenient piece of apparatus can be a 4" (101 mm.) lens used with a standard synchronized shutter.

While the apparatus has been shown processing fabric held in a horizontal plane, it is understood that the apparatus can be inclined in other directions. The fabric In operation the fabric F to be analyzed is placed between the glass plate 67 and the gridded plate 65 and exposed to the light source. The silhouette of the fabric is then photographed by opening the shutter of the photographic portion of the apparatus. As a result the image of the silhouette of the fabric is conveyed through the lens 46 to the photographic medium. When this is developed a negative of the silhouette is obtained. This actually appears as a positive of the fabric, enlarged several times.

Figure 5 shows an analysis made of a x 58 percale fabric. The threads of the fabric appear white whereas the background appears black. In other words, the negative simulates a positive print of the fabric. Defects in the weave can easily be picked out by the extreme contrast between the threads appearing white and the background appearing in black. Quantative aspects of the fabric condition can be easily judged by reference to the grid which appears in white showing through the fabric. A pick count can easily be made by placing the transparent scale shown in Figure 7 over the photograph.

Figure 6 shows another analysis made of a more complicated dobbie weave whose nature is difiicult to observe merely by examining the fabric under a magnifying glass. But the weave can be seen clearly from the photograph.

The actual photographs in both these instances were of the fabric enlarged five times. The scale is likewise enlarged five times so as to obtain a proper reading.

Various modifications can be made, of course, in the specific form of the apparatus, and it can be built in various sizes dependent on desired grid coverage, size of resultant copy desired, and degree of enlargement. The applicant prefersto use a cold grid light as the light source. But, depending on the extract use, almost any other standard type light can be used, for example, photoflood, photoflash or electronic flash. Whether or not a diffusing glass or condenser is necessary between the light source and the fabric can be determined by experimenting with the particular camera.

The invention has particular advantages. For example, it is useful in gauging yield factor at various key stages of processing. This is important in cost analysis. The method ,can be used for analyzing cloth and following variations in structure and count through processing. The method has the advantage of being able to record on paper, film, or glass, and polaroid" film or similar type of fast print medium for laboratory or other recording purposes. It is of particular advantage in cloth analysis showing clearly and definitely structural variations in both weaving and yarn construction. The apparatus can be a fixed table apparatus for the laboratory or portable for working on cloth in process.

It is a phase of the invention to analyze cloth during processing. The cloth is held taut. The light source is placed at one side of the cloth and the photographic apparatus at the other and the silhouette photograph taken in the manner described. I

The apparatus can be used for yarn as well as woven fabric. In this case the intensity of the light will require adjustment. Light intensity also requires adjustment for different types of fabric. Adjustment can be made by adjusting the size of the aperture and the distance of the light source from the fabric.

The apparatus can be adapted for visual scanning, by substituting a ground glass plate for the camera back, and placing a light hood in position, to cut out extraneous light.

I claim:

1. An apparatus for analyzing fabric for structural defects, comprising, a base, a lens mounted in the base, an arm pivoted to the base, a threaded collar in said arm, a fabric holder including a threaded neck, said neck adapted to threadably engage said collar, a threaded ring on said neck adapted to lock the neck against the collar, an enclosed casing portion extending from the neck and tapering outwards to a rim defining an open mouth, a transparent window mounted on said rimacross said mouth, and means for holding fabric in contact with said window.

2. An apparatus for analyzing fabric for structural defects, comprising, a base, a lens mounted in the base, an arm connected to the base, a threaded collar in said arm, a fabric holder including a threaded neck, said neck adapted to threadably engage said collar, a threaded ring on said neck adapted to lock the neck against the collar, an enclosed casing portion extending from the neck and tapering outwards to a rim defining an open mouth, a transparent window mounted on said rim across said mouth, and means for holding fabric in contact with said window.

3. An apparatus for analyzing fabric for structural standards, comprising in combination, a stand having an upright, an arm connected to the upright and extending laterally therefrom, a camera connected to the arm and having its lens adjacent thereto, a second arm mounted on said first arm and having a portion projecting over said lens and spaced therefrom, a fabric-holding member mounted on said second arm and adapted to hold a piece of fabric in fixed relationship to said lens, a second arm extending from said stand and lighting means mount- 4 ed on said second arm to project light through the fabric on said fabric holder, and a shield extending from the fabric holder in the direction of the lens to shield the fabric from light at the side adjacent the lens.

4. An apparatus for analyzing fabric for structural standards, comprising in combination, a hood having at one end means for holding a photographic medium and at the other end a photographic lens, a casing in front of the lens defining an enclosed light passageway for shielding the fabric from extraneous light having one extremity adjacent 'to but spaced from the lens, the casing accommodating at the other end of the passageway a support having a transparent portion, a means for adjusting the casing toward and away from the lens, a calibrated grid on the transparent portion of the support and means for holding a fibrous textile fabric to the support and in direct line with the lens and photographic medium superimposed on the transparent portion whereby the parts of the fabric are distributed in relation to the lines of the grid, a light source spaced from the support, on the side opposite the lens, and a shutter for said photographic means.

5. An apparatus for analyzing fabric for structural standards comprising in combination, a supporting frame. means mounted on the frame for photographing the fabric including a lens and means for holding a photographic medium spaced from the lens to receive light from the lens, fabric-retaining means mounted on the frame for retaining the fabric in the field of the lens, and a light source mounted on the frame adapted to project light through the fabric-retaining means to the lens, and a housing for shielding the fabric from extraneous light at the side adjacent to the lens, means for moving the housing and fabric-retaining means towar and away from the lens, the parts being so arranged that the fabric-retaining means is at a predetermined distance from the lens and the lens a predetermined distance from the photographic medium whereby the silhouette of the fabric may be photographed at a definite enlargement.

6. An apparatus according to claim 5 in which a transparent grid is included on the fabric-retaining means whereby it is in position to be photographed in juxtaposition with a fabric on the fabric-retaining means.

References Cited in the file of this patent UNITED STATES PATENTS 689,361 Moe Dec 17, 1901 1,015,730 Gill Jan 23, 1912 1,199,980 Gtlbreth Oct 3, 1916 1,379,905 Down May 31, 1921 1,831,536 Luhn Nov 10, 1931 1,911,142 Cahrll May 23, 1933 2,048,879 Moran July 28, 1936 2,159,035 McGrath May 23, 1939 2,351,770 Koenig June 20, 1944 2,355,465 Oberkirk Aug. 8, 1944 2,521,483 Scatena Sept. 5, 1950 FOREIGN PATENTS 845,181 France May 8, 1939 OTHER REFERENCES Circular No. 39 of the U. S. Bureau of Standards, December 16, 1912, pages 9, 10, 1'1.

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