Method And Apparatus For Counting The Number Of Individual Filaments Composing A Multifilament Yarn

Abstract

Method and apparatus for counting number of individual filaments having circular cross sections and composing a bright or dull multifilament synthetic yarn. The individual filaments are aligned on a flat surface of a transparent member without intervened space between any adjacent two filaments. A light is projected perpendicularly to the aligned individual filaments through the transparent member and a real image of bright lines created by the above-mentioned light projection as well as a condensing function of the individual filaments is focused upon a screen. The number of bright lines in the real image is counted. The result obtained by this counting represents number of individual filaments composing the multifilament yarn.

Description

SUMMARY OF THE INVENTION

The present invention relates to a method and apparatus for counting the number of circular cross sectional individual filaments composing a bright or dull multifilament yarn in a substantially no-twist condition.

As it is well known, the conventional synthetic multifilament yarn is a bundle of a predetermined number of circular cross sectional individual filaments. However, because of partial breakage of individual filaments during the mill processing, for producing the multiflament yarn, the number of individual filaments may be changed from the above-mentioned predetermined number. This type of yarn is hereinafter referred to as an abnormal multifilament yarn, so as to distinguish it from a normal multifilament yarn composed of a predetermined number of individual filaments.

The above-mentioned breakage of individual filaments may seldom happen. However, it is very difficult to distinguish the abnormal multifilament yarn from the normal multifilament yarn by means of testing the appearance of the yarn during the spinning process, or the successive processes such as twisting, warping, sizing, weaving or knitting, or dyeing. According to our experience, the yarn defect due to the abnormal multifilament yarn can be found during the final stage of the mill processing for producing textile goods, such as the inspection process after weaving or dyeing. However, even when the yarn defects can be found during the inspection process, it is almost impossible to repair the product and, therefore, the economic loss due to the above-mentioned yarn defect is quite large.

Consequently, even though the breakage of individual filaments during the mill processing may seldom happen, the test of inspecting for abnormal yarn is a very important item in carrying out the quality control of the produced yarn.

Generally, the above-mentioned test has been manually carried out. That is, it is the normal testing procedure that the individual filaments of the multifilament yarn are separated manually and then the number of individual filaments is counted. The test for counting the number of individual filaments composing the multifilament yarn is troublesome, and it is necessary to spend a fairly long time carrying out this test. Consequently, the above-mentioned inspection test is one of the big obstacles to the rational management of mill operation.

The principal object of the present invention is to provide a method for eliminating the above-mentioned drawback of the inspection test for picking-up the abnormal multifilament yarn.

Another object of the present invention is to provide an apparatus for carrying out the inspection test according to the method of the present invention.

According to the present invention, the circular cross-sectional individual filaments of a multifilament yarn are firstly aligned in parallel condition without intervening space between adjacent individual filaments. This alignment is carried out on a support member having a flat transparent surface, or a flat surface provided with a transversal slit, which permits passage of light. Then a light is projected to the aligned filaments through the flat surface of the support member so that the direction of the light is substantially perpendicular to the flat surface of the support member.

As each individual filament has a circular-lateral cross section, each individual filament has a so-called light condensing function. Consequently, a real image of bright lines is created at a position opposite the side of the light source with respect to the support member. Since the same number of bright lines are created as the number of individual filaments, it is very easy to determine the number of individual filaments by visually or automatically counting the number of the bright lines. In the apparatus according to the present invention, means for aligning the individual filaments of a multifilament yarn as mentioned above, means for creating the bright lines as a real image and means for enlarging the real image for counting the number of bright lines are essential elements.

Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawings, to which the scope of the invention is in no way limited.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of the inspection apparatus for counting the number of individual filaments composing a multifilament yarn according to the present invention;

FIG. 2 is a perspective view of a support member applied for the apparatus shown in FIG. 1;

FIGS. 3 and 4 are cross-sectional side views of the support member for illustrating how to align the individual filaments thereon;

FIGS. 5A, 5B, 5C and 5D are explanatory enlarged sketches to show how the individual filaments are aligned;

FIG. 6 is a schematic cross sectional view of a plurality of individual filaments aligned upon a supporting member, showing the principle of creation of the bright lines;

FIG. 7 is a sketch of one example of an enlarged real image created on an inspection glass of the apparatus shown in FIG. 1;

FIG. 8 is a schematic side view of the inspection apparatus which modifies the counting system of the embodiment shown in FIG. 1;

FIG. 9 is a perspective view of a practical inspection apparatus for counting the number of individual filaments composing a multifilament yarn according to the present invention;

FIG. 10 is a side view, partly in section, of the main part of the apparatus shown in FIG. 9;

FIG. 11 is a perspective view of an auxiliary member to provide vibration upon the individual filaments, utilized for the apparatus shown in FIG. 1,

FIG. 12 is a perspective view of a modification of the supporting member of the arrangement of FIG. 2, and

FIG. 13 is a cross sectional view of the arrangement of FIG. 12 taken along the lines 13--13.

DETAILED ILLUSTRATION OF THE INVENTION

For the sake of easy understanding of the present invention, a principal apparatus for counting the number of individual filaments, composing a multifilament yarn, according to the present invention is illustrated first.

Referring to FIGS. 1, 2 and 3, a multifilament yarn 1 is deposited on a supporting member 2, provided with a supporting surface 2a, in such a way that the individual filaments 1a are aligned in parallel condition without intervening space between two adjacent individual filaments. However, in practice, it is very difficult to align the individual filaments upon the supporting surface 2a as mentioned above. To solve this problem, a particular method for aligning the individual filaments 1a is considered. That is, the individual filaments 1a of the multifilament yarn 1 are supported by the supporting surface 2a, of the member 2, in laterally slidable condition. The support member 2 is made of a transparent material, and its lateral cross-section is of a triangular shape so as to form a horizontally supporting edge portion which supports the individual filaments 1a. Therefore, this supporting edge corresponds to the above-mentioned supporting surface 2a. To prevent any damage of the individual filaments 1a, the edge which forms the supporting surface 2a must be round in shape. A pair of guide members 3a and 3b are rigidly mounted on the corresponding inclined surfaces 2a or 2b respectively, of the member 2 in such a way that the projection of the multifilament yarn 1 passes over the guide members 3a and 3b. Each guide member 3a and 3b is provided with an arched recess 4 at a position where the projection of the multi-filament yarn passes. When the multifilament yarn 1 is deposited upon the supporting member 2, it may be assumed that the individual filaments 1a are positioned in several groups as shown in FIG. 5A. However, if the multifilament yarn 1 is provided with reciprocal displacements in the lateral direction along the edge of the supporting member 2 under a certain tension, the individual filaments 1a are aligned as shown in FIG. 5B, where intervening spaces can be observed between certain adjacent individual filaments 1a. In this lateral displacement motion, the relative position of the multifilament yarn 1 to the supporting member 2 is as shown in FIG. 3. Next, the supporting member 2 is relatively moved upward to the multifilament yarn 1 so that the multifilament yarn 1 contacts the recess 4 of each guide member 3a and 3b. This condition is shown in FIG. 4. In this condition, if the above-mentioned reciprocal displacement of the individual filaments 1a toward the lateral direction is carried out, the individual filaments 1a can be displaced laterally along the concave surface 4 of the guide members 3a and 3b as shown in FIG. 4, so that the intervening spaces formed between the adjacent individual filaments are eliminated. Consequently, the alignment of the individual filaments upon the supporting surface 2a of the member 2 is changed from the condition shown in FIG. 5B to that shown in FIG. 5C, wherein there is no intervening spaces between adjacent individual filaments 1a. In the above-mentioned explanation, rearrangement of the individual filaments 1a of the multifilament yarn 1 is carried out in two separate steps. However, if the operator is experienced in this operation, he can complete the above-mentioned rearrangement of the individual filaments in one step. In the case of rearrangement of a non-stretched synthetic filament, if the multifilament yarn 1 is deposited upon the supporting surface 2a of the supporting member 2 and simultaneously upon the concave recesses 4 of the guide members 3a and 3b under tension, which is sufficiently strong to stretch of the filaments, the above-mentioned rearrangement of the individual filaments 1a can be completed in one step. Further, according to our experiment, if the multifilament yarn is provided with an up-down vibration instead of lateral reciprocal displacement, the rearrangement of the individual filaments 1a can be satisfactorily attained. The practical device for creating this up-down vibration will be explained later.

When the above-mentioned rearrangement of the individual filaments is completed, the images of these individual filaments 1a are projected by a light from a light source 5 by way of a transparent supporting member 2. As it is well known that the individual filaments 1a are transparent, or at least semi-transparent, even if the filaments include titanium oxide so as to be dull, and each filament has a circular lateral cross section, the light is condensed as it is projected on a condenser lens, as shown in FIG. 8. Consequently, a plurality of bright lines corresponding to each of the individual filaments on an arbitrary plane, for example, a plane identified by line Z--Z in FIG. 6, is observed. It is important to realize that the number of these bright lines is equal to the number of individual filaments composing the multifilament yarn 1. Therefore, if the individual filaments 1a of the multifilament yarn 1 are aligned on the supporting surface of the member 2 as shown in FIGS. 1 and 6, the number of individual filaments 1a can be read by counting the number of the above-mentioned bright lines. For this purpose, the above-mentioned bright lines are enlarged by a convex lens 6, and the enlarged image is projected upon a screen 9 by way of a pair of reflectors 7 and 8 as shown in FIG. 1. The screen 9 is made of frosted glass. This enlarged image is represented by a sketch shown in FIG. 7. In this sketch, the bright lines are represented by a plurality of blanked lines. Therefore, it is easy to confirm whether or not the arrangement of individual filaments on the supporting member 2 is in the above-mentioned desirable condition of alignment as shown in FIG. 6, by checking the intervals between adjacent individual filaments.

According to the above-mentioned principle for counting the number of individual filaments composing a multifilament yarn, an automatic counting method is developed. In this automatic counting method, each bright line involved is detected by utilizing a photocell, so that the number of the bright lines can be automatically counted by means of an electric counter as hereinafter illustrated in detail.

After the above-mentioned desirable alignment of the individual filaments is confirmed, the reflector 7 is turned about a turning shaft 15. This is done by means of a turning mechanism comprising an eccentric cam 12, which can be rotated by a suitable driving mechanism (not shown), and a lever 13 projected from the rear of the mirror of reflector 7, so as to always be urged to the cam surface of the eccentric cam 12 by a helical spring 14. When the eccentric cam 12 is turned counterclockwise from the angular position as shown in FIG. 1, the mirror of reflector 7 is clockwisely turned about the shaft 15. Consequently, the reflected light from the mirror 7 is also deflected upwards. According to the upward deflection of the reflected light from the mirror of reflector 7, the reflected light from the stationary mirror of the reflector 8 is also deflected upward so that the enlarged image projected upon the screen 9 made of a frosted glass moves upward. A photocell 10 is disposed above the screen 9 and the photocell 10 is covered by a cover provided with a slit 11. If the shape of the cam 12 profile is suitably chosen so that when the cam 12 is turned 180.degree., a bright line created at the lowermost position of the real image is passed over the slit 11, the reflected lights corresponding to the bright lines of the real image projected upon the screen 9 pass through the slit 11. In this manner, a plurality of electric pulses are generated by the photocell 10 in such a way that the number of the electric pulses is equal to the number of the bright lines in the real image. Consequently, a conventional pulse counter 16, such as a counter shown in FIG. 18-1, page 668, "Pulse, Digital and Switching Waveforms" by Jacob Millman, Herbert Taub, McGraw Hill Book Company, can be used for counting number of the above-mentioned pulses. To apply this counting system, before starting the counting operation, the automatic pulse counter 16 is reset to zero and its actuation is stopped. In the above-mentioned embodiment, other photoelectric sensors such as a phototube or a phototransistor can be used for the pulse counter 16, instead of the photocell 10.

In the practice of the above-mentioned inspection, the following points must be considered.

1. The suitable wave length of light to energize the photo-cell 10 is near infrared, which is a little longer than that of ordinary light visible to human eyes.

2. When a tungsten lamp is utilized as a light source, the wave length components of the light are in the longer wave lengthside of the light spectrum.

3. If the inspection is applied to a multifilament yarn containing titanium oxide which is used for making the individual filaments dull, the short wave components of the projection light tend to be absorbed by the titanium oxide.

4. The focal distance for a longer wave-length component is longer than that for a shorter one.

That is, according to the above-mentioned phenomena, if real image is focused by the ordinary light on the screen 9 and then the reflected light is projected onto the photocell 10 in the same condition as this focusing, the reflected light does not have sufficient light energy to properly actuate the photocell 10. Consequently, in practice, after focusing the real image visible to human eyes on the screen 9 so as to confirm the alignment condition of the individual filaments 1a on the supporting member 2, it is better to change the distance between the lens 6 and the supporting member 2 so as to focus the real image by the longer wave length components on the photocell 10 for energizing it. To attain this purpose, in the embodiment shown in FIG. 1, the supporting member 2 is displaceably mounted on a pair of eccentric cams, 17a and 17b, in such a way that the supporting member 2 can be positioned at two predetermined horizontal positions. The upper position of these two positions corresponds to a first supporting position F.sub.1 for focusing the real image by ordinary light on the screen 9. The lower position corresponds to a second supporting position F.sub.2, for focusing the real image by the longer wave length components on the photocell 10. When these cams 17a, 17b are turned 180.degree. from the angular positions shown in FIG. 1, the supporting member 2 is displaced downwardly from the position F.sub.1 to the position F.sub.2. The distance between position F.sub.1, F.sub.2 is suitably chosen so as to compensate for the above-mentioned loss of light energy.

As already illustrated, the counter 16 is set so that it does not work until the lowermost bright line in the real image passes over the slit 11 according to the upward movement of the real image. Also the counter 16 is reset to zero during the above-mentioned upward movement of the real image. Next, when the eccentric cam 12 turns over 180.degree., the reflector 7 is returned to the position used for focusing the real image on the screen 9. By this return motion, the real image is displaced downward so that the bright lines of the real image pass over the slit 11. Consequently, the number of electric pulses corresponding to the number of individual filaments composing the multifilament yarn, are generated by the photo-cell 10, and these electric pulses are automatically counted by the electric counter 16. When the eccentric cam 12 turns to its position shown in FIG. 1, the eccentric cams 17a, 17b are again turned 180.degree. so as to displace the supporting member 2 to its position F.sub.1. Then, the inspection apparatus is ready for the succeeding inspection.

In the above-mentioned embodiment, the effect caused by the difference of wave-length of the projected lights is compensated by changing the position of the supporting member 2. However, it is also acceptable to apply an elongated light passage between the reflection mirror 6 and the photocell 10 so as to compensate for the above-mentioned effect. The embodiment shown in FIG. 8 relates to this compensation method. For the sake of easy understanding, the elements having the same functions as that of the elements shown in FIG. 1 are represented by the same reference numerals as those shown in FIG. 1, and the illustration of these elements is omitted. In FIG. 8, a stationary prism 18 is disposed above the screen 9 and the photocell 10 is disposed above the prism 18 with a suitable distance therebetween. The slit 11 is disposed below the photocell 10 so as to allow the projection of light deflected by the prism 18 when the real image is reflected by the reflector 8 so that the real image is projected onto the prism 18. If the distance between the prism 18 and the photo-cell 10 is set so as to correspond to the focal distance of ordinary visible light and the near infrared ray, and the light passage distance between the condenser lens 6 and the screen 9 is set so as to focus the real image of the visible light upon the latter, very sharp bright lines of the near infrared ray are focused on the photocell 10. In this embodiment, a reflection mirror may be used instead of the prism 18.

After a trial application of this method in the quality control program of our mill manufacturing synthetic filament yarns, a practical inspection apparatus was designed so as to adopt the above-mentioned inspection method to the normal quality control program in the mill. This practical apparatus is mounted on a carriage for the sake of easy displacement thereof as shown in FIG. 9. In FIG. 9, the inspection apparatus 19 is mounted on a carriage 20 provided with rotatable wheels 21. The inspection apparatus 19 comprises a supporting member 22, a lens system 23 involving a condenser lens, a casing 24 involving means for reflecting light and an inspection window 25 provided with frosted glass for focusing the real image thereupon. An electric counter 26 provided with an indicator is disposed in the casing 24. In this embodiment, a condenser lens is displaceably supported so as to adjust a distance to the test piece aligned upon the supporting member 22. A knob 27 is used for adjusting the position of the condenser lens. A mechanism is applied for adjusting the position of the condenser lens which is similar to the conventional microscope.

As the elements similar to the above-mentioned two embodiments are applied to this practical inspection apparatus, the elements having the same functions as that of the above-mentioned two embodiments are represented by the same reference numerals as the embodiments shown in FIGS. 1 and 8. In the partially cross-sectional side view of this apparatus shown in FIG. 10, a light generated by a tungsten lamp 5 is condensed by a condenser 28, and this condensed light is reflected by a reflection mirror 29 and then condensed again by a condenser lens 30 so as to light the aligned individual filaments positioned upon the transparent supporting member 2. In this embodiment, the electric counting system illustrated in the first embodiment is applied.

Further, to accelerate the alignment of individual filaments in the above-mentioned desirable condition upon the supporting member 2, means for vibrating the multifilament yarn 1 is applied to this practical apparatus where the yarn 1 is positioned upon the member 2. This mechanism is shown in FIG. 11. In FIG. 11, an electric vibrator 31 is disposed on the apparatus and a pair of supporting bars 35 are arranged in parallel so as to connect with the respective guide members 4. One end of the bars 35 is rigidly connected to a connecting bar 33 which is mounted on a part of frame 34 of the apparatus, while another end of the bars 35 is rigidly connected to a metallic connecting bar 32 which is disposed adjacent to a magnet 31a of the electric vibrator 31 and the bar 32 is also mounted on a part of the frame 34. Therefore, when the electric vibrator 31 is actuated, the bar 32 is provided with frequent up and down movement by the magnet 31a, as represented by arrows in FIG. 11, so that the vibration is transmitted to the guide member 4. According to this vibration, the alignment of individual filaments, which is illustrated in detail with reference to FIGS. 5A, 5B, 5C and 5D, can be carried out rapidly.

According to our experience, each inspection can be completed within 2 to 10 seconds. Further, the measuring error is completely eliminated by applying the inspection method according to the present invention in which the inspection of the multifilament yarn is carried out very effectively to improve the quality control program in the mill producing synthetic multifilament yarns.

The shape and the construction of the supporting member 2 can be further modified. That is, in the above-mentioned embodiment, the supporting member 2 shown in FIG. 2 is provided with a round edge member which forms a supporting surface. However, an edge member having polygonal lateral cross section can be used instead of the above-mentioned edge member. Further, instead of applying the edge member made of transparent material, this edge member can be omitted so as to make a slit 50 for permitting the passage of the projected light from the condenser lens as illustrated in FIGS. 12 and 13. In this case, the supporting member has to be formed as a shell body 51 provided with a slit 50 formed at a top central position thereof. By applying this modified supporting member 2, the same result as the embodiments already illustrated can be attained.

Claims

What is claimed is:

1. A method for counting the number of individual filaments, each having circular cross section of a bright or dull multifilament yarn, comprising: a) aligning individual filaments on a flat surface without an intervening space between any adjacent two individual filaments; b) projecting a light from one side of said aligned individual filaments perpendicularly upon said aligned individual filaments, whereby said projected light is condensed by a condensing function of each individual filament to produce bright lines; c) then inspecting the state of alignment of each of said individual filaments by focusing a visual real image of said bright lines, then d) refocusing said real image for suitable rays on a photoelectrical sensor counting means; and e) then counting the number of said bright lines in said real refocused image.

2. A method for counting the number of individual filaments of a multifilament yarn according to claim 1, wherein said operation for aligning said individual filaments is carried out in several steps: firstly, depositing said multifilament yarn upon a flat surface under tension; secondly each individual filament of said multifilament yarn is relatively displaced along said flat surface so that individual filaments are arranged in a row upon said flat surface; thirdly, any intervals between any two adjacent filaments are eliminated by forcing each individual filament into contact with adjacent individual filaments.

3. A method for counting the number of individual filaments of a multifilament yarn according to claim 2, wherein said operation for aligning said individual filaments is carried out by providing vibration thereto so that any intervals between any two adjacent filaments are eliminated rapidly.

4. Apparatus for counting the number of individual filaments, each having circular cross section, and composing a bright or dull multifilament yarn, comprising:

a. means for aligning a plurality of the said individual filaments on a flat surface without intervening space between any two adjacent individual filaments;

b. means for perpendicularly projecting a light upon said aligned individual filaments from one side of said aligned filaments to create a plurality of bright lines;

c. means for focusing an enlarged real image of said bright lines upon a screen disposed at an opposite side of said aligned filaments,

d. automatic means for counting the number of said bright lines in said real image; and

e. means for refocusing said real image upon an actuating photoelectric element of said automatic counting means.

5. Apparatus for counting the number of individual filaments of a multifilament yarn according to claim 4, wherein said aligning means is a transparent supporting member provided with an edge formed at the top portion thereof so that said individual filaments can be aligned on said edge under tension.

6. Apparatus for counting the number of individual filaments of a multifilament yarn according to claim 4, wherein said aligning means is a supporting member provided with an slit for permitting passing of the projected light therethrough so that said projected light perpendicularly projects upon said aligned individual filaments from the underside thereof.

7. Apparatus for counting the number of individual filaments of a multifilament yarn according to claim 4, wherein said aligning means is a supporting member provided with an edge body for disposition of said individual filament under tension, said supporting member and said edge body being made of a transparent material.

8. Apparatus for counting the number of individual filaments of a multifilament yarn according to claim 5, wherein said supporting member is provided with auxiliary guide members for displacing said individual filaments to contact adjacent filaments positioned at both sides thereof.

9. Apparatus for counting the number of individual filaments of a multifilament yarn according to claim 8, wherein said auxiliary guide members are connected to an electric vibrator so that the displacing of individual filaments can be completed rapidly.

10. Apparatus for counting the number of individual filaments of a multifilament yarn according to claim 4, wherein said focusing means comprises a focus lens disposed at another side of said aligning means with respect to said aligned individual filaments, a turnable reflection mirror mounted on a supporting shaft to reflect a real image of said bright lines, a stationary reflection mirror for reflecting said reflected real image projected from said turnable reflection mirror, a screen for receiving said real image reflected from said stationary reflection mirror thereupon, and an adjustment mechanism for adjusting the focus of said image upon said screen.

11. Apparatus for counting the number of individual filaments of a multifilament yarn according to claim 4, said automatic counting means comprises a photoelectric sensor disposed at a position relative to said focusing means as an actuating element and an electric counter counting electric pulses generated by said photoelectric sensor, said means for refocusing said real image upon an actuating element comprising a cam means for changing a passage of reflected light from said turnable reflector in a predetermined passage defined before said photoelectric sensor and said screen.

12. Apparatus for counting the number of individual filaments of a multifilament yarn according to claim 4, wherein said means for refocusing said real image upon said photoelectric sensor further includes a reflecting element disposed between said stationary reflection mirror and said photocell so as to change the length of the light passage.