CN108946327B

CN108946327B - Yarn breakage sensor for textile equipment

Info

Publication number: CN108946327B
Application number: CN201810347789.6A
Authority: CN
Inventors: G·贝尔托奇; P·泽诺尼
Original assignee: LGL Electronics SpA
Current assignee: LGL Electronics SpA
Priority date: 2017-05-17
Filing date: 2018-04-18
Publication date: 2021-07-27
Anticipated expiration: 2038-04-18
Also published as: IT201700053150A1; EP3403961B1; CN108946327A; EP3403961A1

Abstract

A yarn break sensor for a textile apparatus, comprising: a main body (20); a lever (24) suitable for engaging the yarn (Y) with a portion (24a) of the lever and pivoting about an axis (A) with respect to the body (20) to rotate from a first position to a second position after a yarn break; -detection means comprising a first detection element (30) integral with the lever (24) and a second detection element (32) integral with the body (20), arranged substantially along the trajectory of the first detection element (30) so as to face it with the lever (24) in said second position and generate a corresponding breakage signal, said first detection element (30) or said second detection element (32) being supported in a position adjustable by adjustable support means (36) substantially along the trajectory of the first detection element (30).

Description

Yarn breakage sensor for textile equipment

Technical Field

The invention relates to a yarn break sensor (yarn break sensor) for a textile machine.

Background

It is known that during the weaving process, the yarn can be fed to a downstream textile machine, in particular a knitting machine, by means of a "yarn storage" yarn feeder.

Stored yarn feeders are generally provided with a drum (drum) supporting a plurality of loops of yarn wound thereon, which are adapted to be unwound as required by the downstream machines. When the yarn is unwound from the reel, it can be reloaded by a motorized arm which, like a rotary body, rotates about an axis coaxial with the reel axis, or, in other types of feeders, by rotating the reel itself.

The storage yarn feeder may be provided with a sensor adapted to detect an accidental breakage of the yarn. The sensor is generally arranged immediately downstream of the drum and may comprise a lever pivoted at an intermediate point about an axis transverse to the direction of advance of the yarn. One end of the rod carries a magnet, while the opposite end is urged by a spring, functionally connected to the rod, to slidably engage the yarn output from the drum.

In the event of yarn breakage, the lever is released and rotates, pushed by the spring, bringing the magnet in front of the hall-effect sensor, which is mounted on a printed circuit integrated with the sensor body. The hall effect sensor thus generates a yarn break signal, which is transmitted to the feeder control unit.

As is well known to those skilled in the art, it is crucial that the yarn break signal arrives in the shortest time possible. In fact, the timeliness of the intervention of the sensor is a decisive factor in order to prevent defects on downstream machines, such as breakage of the needle, loss of yarn from the needle, etc.; obviously, these drawbacks limit productivity, since they lead to downtime for restoring the correct operating conditions of the machine.

The only way currently known to make the sensor more reactive is to adjust the force exerted by the spring by increasing the preload.

However, as is known, the preload cannot be increased beyond a certain limit, in particular when the operating tension (i.e. the tension at which the yarn is fed to the machine) is relatively low, since it would subject the yarn to excessive disturbances, which could be detrimental to the operation of the machine and to the quality of the knitting produced.

Furthermore, the intervention time of the sensor varies according to the yarn count and the type of yarn being processed.

Disclosure of Invention

It is therefore an object of the present invention to provide a yarn breakage sensor for textile equipment which overcomes the above-mentioned drawbacks of the conventional systems and which, in particular, comprises the possibility of adjusting the reactivity of the sensor on the basis of the yarn count and the type of yarn being processed, without modifying the restoring force of the spring.

Another object of the invention is to provide a break sensor that is relatively simple and inexpensive to manufacture.

This aim and these and other objects that will become better apparent from the following description are achieved by a break detecting sensor having the features set out in the appended independent claims, while the appended dependent claims define further features of the invention, which are advantageous, though secondary.

Drawings

The invention will now be described in more detail with reference to some preferred but not exclusive embodiments thereof, which are shown by way of non-limiting example in the accompanying drawings, wherein:

FIG. 1 is a schematic side view of a generic textile apparatus including a break detection sensor;

FIG. 2 is a side view of a yarn break detection sensor in a first active position in accordance with the present invention;

FIG. 3 is a view similar to FIG. 2 showing the sensor in a second active position;

FIG. 4 is an enlarged view of a detail of FIG. 2;

fig. 5 is an enlarged view of a detail of fig. 3.

Detailed Description

Fig. 1 schematically shows a thread break sensor 10, which is mounted on a storage thread feeder 12. The feeder 12 is provided with a spool 14, the spool 14 carrying the yarn Y wound thereon. The yarn Y is suitable to be unwound according to the requirements of the downstream textile machine, in particular of the knitting machine 16.

The sensor 10 is fixed to an arm 18 projecting longitudinally from the body of the feeder 12 and intersects the yarn immediately downstream of a weft braking device 19, which weft braking device 19 is applied to the output of the reel 14.

The feeder 12 and the knitting machine 16 may be conventional and therefore they will not be described in detail here.

In particular, with reference now to fig. 2-5, the sensor 10 comprises a body 20, the body 20 supporting a yarn guide inlet bush 22 and a yarn guide outlet bush 23 coaxial with each other.

The lever 24 pivots relative to the main body 20 about an axis a spaced from and generally transverse to the axis of the yarn guide bushing at an intermediate point (intermediate point) between the two

yarn guide bushings

22, 23.

The first end 24a of the rod 24 is urged into slidable engagement with the yarn Y downstream of the yarn guide outlet bushing 23 by a spring 26 (only schematically shown in fig. 2 and 3), which spring 26 is functionally connected to the rod 24. The opposite end 24b integrally supports a holder 28 containing a magnet 30. The preload of the spring 26 is adjustable in a conventional manner by means of a knob 31.

In a conventional manner, in the event of yarn breakage, when the spring 26 returns, the lever 24 is released and rotates, bringing the magnet 30 in front of the hall-effect sensor 32, the hall-effect sensor 32 being mounted on a circuit board 34, the circuit board 34 being housed in the main body 20. Thus, the hall effect sensor 32 generates a yarn break signal which is sent to a control unit (not shown) of the feeder 12.

In order to adjust the delay of the sensor response, according to the invention, the hall effect sensor 32 is supported in a position that can be adjusted substantially along the trajectory of the magnet 30 by means of a slider (slider)36, the circuit board 34 being fixed on the slider 36.

The slide 36 is slidable relative to the body 20 in a direction parallel to the axis of the

yarn guide bushings

22, 23 between a low-sensitivity position shown in fig. 2 and 4 and a high-sensitivity position shown in fig. 3 and 5. In the low sensitivity position, the lever 24 needs to be rotated through (trace) an angle α (e.g., about 70-80 °) in order to bring the magnet 30 in front of the hall effect sensor 32. In the high sensitivity position, the lever 24 needs to be rotated through a small angle β (e.g., about 35 ° -45 °), thus significantly reducing the sensor intervention time after a yarn break.

The yarn break detection sensor according to the invention operates in a similar manner to conventional sensors, but according to the set objectives it is possible to adjust the reactivity of the sensor, even on the basis of the yarn count and the type of yarn being processed, without modifying the preload of the spring, simply by changing the position of the slider.

In the embodiments described herein, the preload of the spring can still be varied for greater versatility.

Having described some preferred embodiments of the invention, it is apparent that modifications and variations are possible to those skilled in the art within the scope of the appended claims.

For example, there may be an intermediate adjustment position of the slider to further refine the adjustment of the sensitivity.

Moreover, the slider can slide along a curved trajectory instead of a straight trajectory, so as to better follow the trajectory of the rod 24, or it can even be replaced by other adjustable support means, such as an arm articulated about the axis a, which integrally supports the hall-effect sensor at one end thereof.

Further, in the depicted embodiment, the position of the magnet relative to the rod 24 is fixed, while the position of the hall effect sensor relative to the body 20 is adjustable. However, the opposite solution is also possible, i.e. the hall effect sensor is fixed and the magnet is mounted on the rod in a position adjustable along the trajectory of the magnet itself.

Furthermore, it is understood that the position of the magnet 30 and the position of the hall effect sensor 32 may be reversed; that is, the magnet 30 may be integrated with the slider 36 and the hall effect sensor 32 may be integrated with the lever 24.

Further, the rod may pivot at the ends rather than at the intermediate point, and the magnet may be fixed to the intermediate point of the rod.

Spring 26 may not be necessary if the weight of lever 24 ensures sufficient repeatability, although the spring is useful to ensure the accuracy of operation of the sensor.

Moreover, the axis of oscillation of the lever does not necessarily have to be perpendicular to the direction of travel of the yarn, but may even be parallel, provided that the lever is arranged to engage the yarn with one of its portions (not necessarily the end portion) and the lever is pushed so as to rotate in the event of breakage of the yarn.

Last but not least, detection means other than the magnetic sensor described herein may be used, as long as such means are constituted by two detection elements capable of generating a signal when they are close to each other. For example, an optical sensor consisting of a light emitter and a photocell, or a contact sensor consisting of a mechanical switch and a positioner and the like may be used.

Claims

1. A yarn break sensor for a textile apparatus, comprising:

-a main body (20),

-a lever (24), said lever (24) being suitable for engaging a yarn (Y) with a portion of said lever and pivoting about an axis (A) with respect to said body (20) for rotating from a first position to a second position after yarn breakage,

-detection means comprising a first detection element integral with said rod (24) and a second detection element integral with said body (20), arranged substantially along the trajectory of said first detection element so as to face it with said rod (24) in said second position and generate a corresponding breakage signal,

characterized in that the first detection element or the second detection element is supported by adjustable support means in a position that can be adjusted substantially along the trajectory of the first detection element.

2. Yarn break sensor according to claim 1, characterized in that the adjustable support means comprise a slide (36), the slide (36) being slidable between a low sensitivity position in which the lever (24) needs to be turned through a first angle (a) in order to bring the first detecting element in front of the second detecting element, and a high sensitivity position in which the lever (24) needs to be turned through a second angle (β) smaller than the first angle in order to bring the first detecting element in front of the second detecting element.

3. The yarn break sensor according to claim 2, characterized in that the first angle is comprised between 70 ° and 80 ° and the second angle is comprised between 35 ° and 45 °.

4. The yarn break sensor according to claim 2, characterized in that the slider (36) integrally supports the second detection element and is slidably mounted with respect to the main body (20).

5. The yarn break sensor according to claim 4, characterized in that it comprises a yarn guide inlet bushing (22) and a yarn guide outlet bushing (23), the yarn guide inlet bushing (22) and the yarn guide outlet bushing (23) being coaxial with each other and integral with the main body (20), the slider (36) being slidable in a rectilinear direction substantially parallel to the axis of the yarn guide bushing.

6. Yarn break sensor according to claim 5, characterized in that the yarn guide inlet bush (22) and the yarn guide outlet bush (23) define a path substantially perpendicular to the axis (A).

7. The yarn break sensor according to any of the claims 1-6, characterized in that one of the first and second detection elements is a Hall effect sensor (32) and the other detection element is a magnet (30).

8. The yarn break sensor according to claim 7, wherein the first detection element is a magnet.

9. The yarn break sensor according to any of the claims 1-6 and 8, characterized in that the lever (24) pivots with respect to the body (20) at an intermediate point, engaging the yarn (Y) with a first end (24a) and integrally supporting the first detection element at an opposite second end (24 b).

10. Yarn break sensor according to any one of claims 1-6 and 8, characterised in that the rod (24) is pressed against the yarn by elastic means (26).