CH710797B1 - Measuring device for measuring physical characteristics of threads or yarns in textile fibers. - Google Patents

Abstract

A measuring device (10) for measuring physical characteristics of threads or yarns (F) in textile fibers comprising emitting means (11) of a light beam along an optical path (A), guide means (12) for guiding a wire or yarn (F) along a guide path (B) which is substantially rectilinear and extends for at least a portion along a measuring area (13) intercepted by the optical path (A), receptive means (14) sensitive to said port and arranged along the optical path (A) to receive at least a fraction of the light emerging from the thread or yarn (F) illuminated by the light beam, at least one optical element (15) arranged along said optical path (A) between said emitter means (11) and said receptor means (14) and interposed between said guide path and said receptor means (14), and cleaning means (16) to remove from the measuring device (10) fine dust and which comprise a first body (17) in which a suction duct (18) is defined which is defined between said guide path (B) and said at least one optical element (15) and which has at least one inlet opening (18a), which is in communication with a suction area (19) intercepted by the optical path (A ), and at least one outlet opening (18b) associable with suction means (20) for extracting the dust from the at least one suction area (19) and a second body (21) which is arranged between the path of guide and the optical element (15) and in which at least one emission nozzle (22) of an air jet is formed, in which the emission nozzle (22) has at least one inlet opening that can be associated with feeding means ( 23) of pressurized air and at least one air jet emission opening directed towards the optical element (15), in which at least one outflow path is defined between the first body (17) and the second body (21) which the air stream generated by the at least one jet of air flows from the optical element (15) into the area suction (19) or in the suction duct (18) transporting particles to be extracted therein.

Description

Description [0001] The present invention relates to a measuring device for measuring the physical characteristics of threads or yarns in textile fibers. The present invention relates in particular to an optical measuring device for measuring the "hairiness" and the regularity of threads or yarns in textile fibers.

[0002] With reference to the textile sector, as known, the threads and yarns comprise an elongated central body which is made up of a plurality of interlaced fibers and from which some fibers or portions of them of varying length extend outwards . The term "hairiness" means the set of fibers that protrude from the central body of a thread or yarn towards the outside of it.

[0003] The hairiness of a thread or textile yarn, and in particular its size, is a fundamental parameter which influences both the production process of the thread or yarn, and the manufacturing process and, in particular, the weaving or knitting process of the same, both the quality of the products (woven or knitted) obtained with it.

[0004] The quality of a thread or textile yarn is determined, in addition to the hairiness, by other parameters, among which, in particular, the so-called "regularity" intended as a measure of the level of variation of the linear density of the thread.

[0005] The measurement of the hairiness and regularity of a thread or textile yarn is therefore fundamental for controlling and optimizing the production process of the thread or yarn and thus obtaining threads or yarns of the desired quality.

[0006] With particular reference to the hairiness, various devices have been known for its measurement for a long time which are based on the exploitation of optical phenomena of diffraction, refraction and reflection of light by the thread or yarn under examination.

Known optical devices are described for example in PT 198 2007 5791, EP 0 754 943 B1 (Keisokki Kogyo Co. Ltd), US 5 875 419 (Lawson-Hemphill Ine.), US 4 948 260 (Zellweger Uster Limited), EP 1 624 302 A2 (Premier Evolvics PVT Ltd), WO 02/37 054 (Rieter CZ) and in the Italian application IT 2012 MI 1675.

[0008] These known devices are affected by some drawbacks.

The optical systems used therein comprise a plurality of optical elements, including, in particular, lenses, mirrors and receptors / sensors, which are sensitive to numerous external factors which are difficult to control, including, in particular, the dust, and therefore require frequent cleaning and maintenance by skilled workers.

[0010] During their operation, in fact, powders can penetrate inside these devices and particles or fibers can detach from the wire in question.

[0011] These powders, particles and fibers then tend to accumulate on the optical elements, interfering with the light beam used for the measurement and altering the results.

Therefore, it is often necessary to carry out cleaning operations on the optical elements. These interventions are carried out by specialized technicians who must disassemble the measuring device, clean the optical elements taking care not to damage them and reassemble the device. These interventions, therefore, in addition to requiring the stopping of the measuring devices, are expensive and delicate.

The documents BE 1 003 275, EP 0 094 463 and EP 1 558 798 describe measuring devices, respectively of the optical or microwave resonator type, which comprise cleaning means which operate by blowing or alternately sucking air.

[0014] The object of the present invention is to overcome the drawbacks of the prior art.

[0015] The object of the present invention is in particular to provide a measuring device for measuring the physical characteristics of threads or yarns in textile fibers which allows the optical elements present inside it to be kept clean effectively and without requiring the execution of cleaning interventions by specialized technicians.

Still another object of the present invention is to provide a measuring device for measuring the physical characteristics of threads or yarns in textile fibers which allows the optical elements present inside it to be kept clean even during normal operation, while maintaining the thread or yarn in conditions of stability and alignment along its guiding path.

Another object of the present invention is to provide a measuring device for measuring the physical characteristics of threads or yarns in textile fibers that is particularly simple and functional and with low costs.

These objects according to the present invention are achieved by realizing a measuring device for measuring the physical characteristics of threads or yarns in textile fibers as set forth in claim 1.

Further characteristics are provided in the dependent claims.

The characteristics and advantages of a measuring device for measuring the physical characteristics of threads or yarns in textile fibers according to the present invention will become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings in which:

fig. 1 is a longitudinal section view of a measuring device according to the present invention;

CH 710 797 B1 fig. 2 is a section view of the measuring device according to the plane 11-ll of fig. 1;

fig. 3 is a section view of the measuring device according to the plane lll-lll of fig. 2;

fig. 4 is an axonometric and exploded view of a detail of the measuring device of fig. 1 to 3 and comprising a first body and a second body as described below;

fig. 5 is an axonometric view of the first body of the detail of fig. 4;

fig. 6 is a longitudinal section view of the second body of the detail of fig. 4.

With reference to the figures, a measuring device 10 is shown for measuring the physical characteristics of threads or yarns in textile fibers.

By "physical characteristics" it is meant to indicate, in particular, the hairiness and / or the diameter and / or the structural regularity of a thread or yarn in textile fibers. For simplicity, the description below will refer to an F wire.

[0023] The device 10 is of the optical type and comprises:

- means 11 emitting a beam of light along an optical path indicated by the trace A,

guide means 12 for guiding a thread F along a guide path (indicated by the trace B in fig. 2) which is substantially rectilinear and which extends for at least a section along a measuring area 13 intercepted by the optical path A, is

- receptor means 14 sensitive to light and arranged along the optical path A to receive at least a fraction of the light emerging from the wire F illuminated by the light beam.

The device 10 furthermore comprises one or more optical elements 15 interposed along the optical path A between the emitting means 11 and the receiving means 14

- and, in particular, between the guide path B and the receiving means 14

- and which are capable of interacting with the light beam to collimate it, divert it, spread it, diffract it or other. The optical elements 15 can be constituted, for example, by optical lenses of any nature, bodies adapted to diffuse, refract or diffract the light beam or other.

By "measuring area 13" is meant an area, a volume or a space crossed by the wire F along its guiding path B and at at least a portion of which the wire F is illuminated by the light beam .

According to a feature of the present invention, the device 10 comprises cleaning means 16 for removing the dust which is generated and / or which accumulates inside it and, in particular, the dust which is generated and / or which accumulates. near the optical elements 15 so as to avoid that they alter the measurements.

[0026] It is specified that by "dust" it is meant to indicate both powders present or in any case penetrated inside the device 10, and fibers or dust of fibers which detach from the thread F for example due to the rubbing with the guide means 12 .

The cleaning means 16 comprise a first body 17 in which a suction duct 18 is defined which is defined between the guide path B and the optical element 15 and which has at least one inlet opening 18a, which is in communication with a suction area 19 intercepted by the optical path A, and at least one outlet opening 18b associated with suction means 20 for the extraction of particles from the suction area 19.

[0028] The suction means 20 are only schematically shown in fig. 1 and not further detailed, since, as immediately understandable to the person skilled in the art, they are made up of any apparatus or system suitable for creating a depression.

[0029] It should be noted that "suction area" 19 means an area, a volume or in any case a space inside the device 10 and affected, for at least a portion, by the suction action applied by means of the suction means 20.

[0030] The suction area 19 is defined at the measurement area 13 or at the optical element 15, depending on the structure of the device 10.

Furthermore, according to the present invention, the cleaning means 16 comprise a second body 21 which is arranged between the guide path B and the optical element 15 and in which at least one emission nozzle 22 of a jet of jet is obtained air, wherein the emission nozzle 22 has at least one inlet opening 22a, which can be associated with pressurized air supply means 23, and at least one emission opening 22b of the air jet inside the device 10. In particular,

CH 710 797 B1 the emission opening 22b faces the optical element 15 in such a way that the jet of air leaving it hits the surface of the optical element 15 that you want to keep clean.

Still more particularly, the emission opening 22b is faced with the surface of the optical element 15 facing the guide path B (or directly facing it) and, therefore, more directly affected by the powders and fibers that detach from wire F.

[0033] The feeding means 23 are only schematically represented in fig. 1 and are not further detailed, since, as immediately understandable to those skilled in the art, they consist of any apparatus or system suitable for supplying air, or other gas, under pressure at a pressure value and with a flow rate suitable for the purpose; for example, the air is fed at a pressure of 6 bar with a flow rate of 50 normal-liter / minute.

[0034] It is further specified that the distinction between "first body" and "second body" is made for the purpose of clarity of presentation only and should not be understood in any limiting sense. In particular, the first body 17 and the second body 21 could also be made in a single body or in turn be made up of several assembled elements.

[0035] The suction area 19 is defined in correspondence with the measurement area 13, towards which the particles entrained by the jets of air emitted by the emission nozzles 22 are conveyed.

In fact, at least a flow path is defined between the first body 17 and the second body 21 along which the air stream generated by the air jets emitted by the one or more emission nozzles 22 flows from the optical element 15 in the suction area 19 or in the suction duct 18 transporting the dust to be extracted there.

In practice, an overpressure zone is generated in the vicinity of the surface of the optical element 15 facing and exposed to the guide path B of the wire F, while in the vicinity of the guide path B of the wire F a zone is simultaneously created depression. The pressure difference between these areas generates a current of air leaving the device 10 which carries with it dust which could alter the measurements in particular if it settles on the optical element 15.

[0038] With particular reference to the embodiment shown in the attached figures, the first body 17 and the second body 21 will be described in greater detail below.

[0039] The first body 17 is constituted by a substantially parallelepiped block crossed by a through hole which defines the suction duct 18.

[0040] The suction duct 18 is open at the opposite ends and the first body 17 is arranged in such a way that the suction duct 18 is coaxial with the optical path portion A which intercepts the suction area 19.

[0041] The inlet opening 18a is obtained at one of the two axially opposite ends of the suction duct 18 and is faced with the suction area 19.

[0042] The outlet opening 18b is defined on the side wall of the suction duct 18 and opens into a seat 24 in which a fitting 25 is housed for connection with the suction means 20.

[0043] The end of the suction duct 18 opposite to that in which the inlet opening 18a is defined is also open and faces the optical element 15.

The first body 17 also has lowered and flared seats 26 aligned and opposite each other and which are crossed by the guide path B of the wire F.

[0045] The first body 17 then has holes 27 for fixing to the containing body 28 of the device 10 by means of screws 29.

[0046] The second body 21 consists of a tubular element open at the opposite ends 21 a, 21 b and arranged coaxial with the suction duct 18.

[0047] The second body 21 has a first end 21a, which faces the optical element 15 and near which one or more emission nozzles 22 are defined, and a second end 21 b, which is in communication with or opens in the suction duct 18. The second body 21 itself therefore defines the flow path of the air stream from the optical element 15 towards the suction area 19.

[0048] The first end 21 a of the second body is substantially in contact with the surface of the optical element 15 to which it is faced.

[0049] The second end 21 b of the second body 21 lies instead inside the suction duct 18.

[0050] In greater detail, the second body 21 has, along its axial development, a first portion 210 with an external diameter greater than that of a second portion 211.

[0051] The first portion 210 extends between the first end 21a and a shoulder 212 which rests against a corresponding surface of the first body 17.

One or more emission nozzles 22 are obtained in correspondence with this first portion 210, for example two or four, each of which is constituted by a through hole whose axis is inclined by an angle a with respect to the axis of the second body 21 itself, where the angle a varies between 20 ° and 40 ° and is preferably equal to 30 °.

CH 710 797 B1 [0053] The second portion 211 is arranged inside the suction duct 18 in a coaxial way; the second portion 211 has an external diameter smaller than the internal diameter of the suction duct 18.

[0054] The tubular element that forms the second body 21 has an axial through hole that has a conical section diverging towards the first end 21 a and connected to a circular section with a constant section which opens into the second end 21 b.

[0055] The conical section is obtained in correspondence with the first portion 210 and the outlet openings 22b of the emission nozzles 22 open at it.

[0056] At least one sealing gasket of the type of an O-ring 30 is interposed between the first body 17 and the second body 21.

[0057] With particular reference to the embodiment of the device 10 shown in the attached figures, it is of the type described in patent application no. MI 2012 A 001 675.

As far as we can see here, this device 10 comprises a cylindrical-type containment body 28 along whose longitudinal axis the optical path A develops.

[0059] The interior of the containment body 28 is coated with a material absorbing the light emitted by the emitting means 11 and, in particular, the rays of it not parallel to the optical path A.

[0060] The emitting means 11 and the receiving means 14 are fixed to the opposite ends of the containing body 28.

[0061] The emitting means 11 are of the type suitable for emitting a laser light beam and are fixed to the containment and support body 28 by means of support means 31 advantageously of the orientable type so as to be able to center the laser light beam with the receiving means 14.

The receptor means 14 are of the type of a single photodiode (of the type for example of the photodiode called "Si-PIN phodiode S 1722-02" by Hamamatsu) or a single-element charged-coupled-device CCD ( photodiode).

[0063] The output signal from the receiving means 14 is sent to processing means of the type of a PC.

The guide means 12 are constituted by plates which have a notch in which the wire F is inserted.

[0065] The thread F is made to run along the guide path B by means of driving means adapted to drag the thread F at a predefined and controlled speed along the straight path B and not further described or illustrated being of a type known to branch technician. These driving means can be part of the device 10 itself or of a measuring apparatus in which the device 10 is integrated and which can be installed in the laboratory or on a textile machine.

[0066] The containment body 28 has a transverse slot 32 through which the wire F is inserted into the device 10.

One or more diaphragms 33 are arranged between the emitting means 11 and the guide path B, each of which has a central hole 34 arranged coaxial with the optical path A and with a calibrated diameter smaller than that of the laser light beam, so to clean the latter from the rays not perfectly parallel.

[0068] Between the receptor means 14 and the guide path B there is an optical element 15 consisting of a diffusion body or an optical diffraction element of the light emerging from the wire F.

[0069] This diffusion body is a single body or consisting of several elements assembled together, made of a translucent or semitransparent material.

[0070] Advantageously, this translucent or semitransparent material is a polymeric material, preferably comprising acrylic resins, even more preferably PMMA (polymethylmethacrylate), as described in the aforementioned patent application MI 2012 A 001 675. On the face of the optical element 15 facing the straight path B, there are means for blocking direct light from the laser light beam, which comprise an internally hollow cylinder which has an internal diameter equal to that of the laser light beam in exiting the diaphragms 33, an open end facing the emitting means 11 and an opposite closed end, is arranged coaxially with the optical path A and is covered with a coating absorbing the laser light in use.

[0071] The receiving means 14 can be placed in direct contact with the optical element 15 in correspondence with the face of it opposite to that facing the straight path B.

[0072] The first body 17, in which the second body 21 is partially inserted, is interposed between the guide path B and the optical element 15.

[0073] In particular, the first body 17 is arranged in such a way that the inlet opening 18a of the suction duct 18 faces the guide path B and, therefore, towards the wire F, so that the suction area 19 is defined in the measurement area 13.

[0074] The second body 21 is arranged between the first body 17 and the optical element 15 with the first end 21a resting on the face of the optical element 15 facing the guide path B and with the second end 21 b housed in the suction duct 18. The emission nozzles 22 have the respective emission opening 22b facing the face of the optical element 15 facing the guide path B, so that the jets of air emitted by them hit this face

CH 710 797 B1 removing any particles from it. The air current that is thus formed is conveyed into the suction duct 18 or in any case towards the suction area 19 from which it is sucked out of the device 10.

[0075] The suction action exerted at the suction area 19 through the suction duct 18 and the suction means 20 conveys any dust present in it or otherwise conveyed to the outside of the device 10.

[0076] Advantageously, the suction area 19 is defined in correspondence with the measurement area 13 that is in correspondence with an area crossed by the guide path B and intercepted by the optical path A so as to remove from it in particular dust, particles and fibers that can detach from the thread F while it is run along the guide path B.

[0077] For a person skilled in the art, the operation of the device 10 and, in particular, of the cleaning means 16 according to the present invention is immediately understandable from the above description and from the attached drawings.

It should be noted that the present invention (i.e. the cleaning means 16) can be applied to measuring devices which are also different from that represented in the attached figures and subject of Italian patent application no. MI 2012 A 001 675. For example, the present invention (ie the cleaning means 16) could be applied to measuring devices as described in PT 19 820 075 791, EP 0 754 943 B1 (Keisokki Kogyo Co. Ltd), US 5 875 419 (Lawson-Hemphill Ine.), US 4 948 260 (Zellweger Uster Limited), EP 1 624 302 A2 (Premier Evolvics PVT Ltd), WO 02/37 054 (Rieter CZ).

[0079] The measuring device object of the present invention has the advantage of preventing dust and fibers (dust, fibers or other) from depositing and accumulating inside it, which could alter the measurements.

In particular, the measuring device object of the present invention allows to keep the optical components by which the measurement is carried out clean, i.e. components such as lenses, diffusers or the like and / or the receptor / sensor means.

By performing a suction action in correspondence with the measurement area - that is in correspondence with an area crossed by the wire and affected by the optical path of the light beam used for the measurement - it is possible to remove from the device powders, particles and fibers which are formed here, for example due to the sliding of the wire, preventing them from spreading inside the device itself.

[0082] In use, the injection of the jets of air under pressure occurs simultaneously with the suction action even during the execution of the measurement tests on the wire in question; the generation of an over-pressure zone (created by the jets of air under pressure) and a simultaneous depression zone (created by the suction action) in communication with each other creates a flow of air that moves the dust away without altering the motion and the path of the thread under consideration.

[0083] The injection of pressurized air jets (injection which takes place simultaneously with the suction action) inside the device itself - and, in particular, on the faces of the components of it that are to be kept clean and the current conveyed generated by them towards the suction it allows to improve the cleaning action.

Furthermore, the measuring device according to the present invention allows not to alter the trend of the thread or yarn being measured; in particular, the creation of an overpressure zone and a depression area communicating with each other allows not to deviate the wire from its guiding path and, therefore, not to alter the measurements performed.

[0085] The measuring device for measuring the physical characteristics of threads or yarns in textile fibers thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the invention; moreover, all the details can be replaced by technically equivalent elements. In practice, the materials used, as well as the dimensions, may be any according to the technical requirements.

Claims (7)

claims 1. Measuring device (10) for measuring the physical characteristics of threads or yarns (F) in textile fibers comprising: - means emitting (11) a beam of light along an optical path (A), guide means (12) for guiding a thread or yarn (F) along a guide path (B) which is substantially rectilinear and which extends for at least a section along a measuring area (13) intercepted by said optical path (TO), - receptor means (14) sensitive to said light and arranged along said optical path (A) to receive at least a fraction of the light emerging from the thread or yarn (F) illuminated by said light beam, - at least one optical element (15) arranged along said optical path (A) between said emitting means (11) and said receptor means (14) and interposed between said guide path (B) and said receptor means (14), and - cleaning means (16) for removing dust from said measuring device (10), characterized in that said cleaning means (16) comprise - a first body (17) in which a suction duct (18) is defined which is arranged between said guide path (B) and said at least one optical element (15) and which has at least one inlet opening (18a) , which is in communication with an aspiration area (19) intercepted by said optical path (A), and at least one outlet opening (18b) associable with aspiration means (20) for the extraction of said dust from said at least a suction area (19), and - a second body (21) which is arranged between said guide path (B) and said at least one optical element (15) and in which at least one emission nozzle (22) of an air jet is obtained, in which said nozzle emission (22) has at least CH 710 797 B1 an inlet opening (22a) associable with means for supplying pressurized air (23) and at least one emission opening (22b) of said air jet facing towards said at least one optical element (15), wherein at least one outflow path is defined between said first body (17) and said second body (21) along which the air stream generated by said at least one jet of air flows from said at least one optical element (15) in said area of suction (19) or in said suction duct (18) by transporting particles to be extracted therein. 2. Device according to claim 1, characterized in that, in use, the injection of said jets of air under pressure occurs simultaneously with said suction. Device according to claim 1 or 2, characterized in that said at least one suction area (19) is defined in correspondence with said measuring area (13) or in correspondence with said at least one optical element (15). Device according to one of the preceding claims, characterized in that said suction duct (18) is open at at least one of its two axially opposite ends and is coaxial with the optical path (A) which intercepts said suction area (19), wherein said at least one inlet opening (18a) is formed at said open end of said suction duct (18) and said outlet opening (18b) is defined on the side wall of said suction duct ( 18). Device according to one of the preceding claims, characterized in that said suction area (19) is defined in correspondence with said measuring area (13). Device according to one of the preceding claims, characterized in that said suction duct (18) is open at its axially opposite ends and by the fact that said second body (21) consists of a tubular element open at the opposite ends and arranged coaxially to said suction duct (18) and having a first end (21 a) facing said at least one optical element (15) and near which said at least one emission nozzle (22) and a second end (21 b ) which is in communication with or leads into said suction conduit (18), wherein said tubular element defines said outflow path. Device according to one of the preceding claims, characterized in that it comprises a cylindrical containment body (28) along the longitudinal axis of which said optical path (A) develops and at the opposite ends of which said emitting means (11) are respectively fixed , Which are capable of emitting a laser light beam, and said receptor means (14), which are single-photodiode or single-element CCD, in which said containment body (28) is internally coated with a absorbent material called laser light and has a transverse slot (32) for insertion through it of said wire (F), - one or more diaphragms (33) interposed between said emitting means (11) and said guide path (B) and each of which has a central hole (34) coaxial with said optical path (A) and with a calibrated diameter smaller than that of said laser light beam, - said at least one optical element (15) interposed between said receptor means (14) and said guide path (B) and constituted by a diffusion or diffraction body made of translucent or semitransparent material, - blocking means (35) of the direct light of the laser light beam, which blocking means (35) are arranged on the face of said optical element (15) facing said guide path (B) and comprise an internally hollow cylinder which has an internal diameter equal to that of the laser light beam exiting said diaphragms (33), an open end facing towards said emitting means (11) and an opposite closed end, is arranged coaxial to said optical path (A) and is internally covered with an absorbent coating called laser light, - wherein said first body (17) is interposed between said guide path (B) and said optical element (15) so that said inlet opening (18a) of said suction duct (18) faces towards said path guide (B) and in which said second body (21) is arranged between said first body (17), in which it is partially inserted, and said optical element (15) with said first end (21 a) resting on the face of said optical element (15) turned towards said guide path (B) and with said second end (21 b) housed in said suction duct (18), said emission nozzles (22) having the respective emission opening (22b) facing said face of said optical element (15) facing towards said guide path (B). 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