Apparatus For Controlling The Movement Of Piece Goods In Dyeing And Finishing Machines

Abstract

This invention provides a control apparatus for use with a dyeing and/or finishing machine of the kind in which a skein or rope of material is passed through a closed circuit including tubular conduits. A magnet or metal element moves with the skein or rope and in one zone of the closed circuit an electromagnetic detector is arranged to provide pulses in response to the passage of the said element through the zone. If the pulses fail to appear within a given interval of the time taken for one complete circuit of the dyeing machine in normal operation of the latter the detecting circuit operates an alarm device signalling stoppage of the skein or rope in the machine.

Description

This invention relates to an apparatus for controlling the movement of piece goods in dyeing and finishing machines and more particularly, but not exclusively, it relates to an apparatus for controlling the movement of piece goods in machines for dyeing skeins of material.

It is known that, before undergoing a treatment of dyeing and/or finishing of said type, the material is "constricted" to assume substantially the form of a skein or rope. Under such conditions the skein of material is pressed and stretched as it passes in a tortuous path through a dyeing and/or finishing bath, so that it makes good contact with the treatment liquid.

Known machines for dyeing skeins of material are generally formed by a substantially tubular U-shaped tub having substantially vertical tubular legs which communicate at their upper ends with the inside of a chamber in which a skein-winder is rotatably mounted for supporting and pulling the skein of material through the bath. The dyeing and finishing liquid is fed into the tub until it reaches a certain level in the tubular legs. To be treated in such dyeing machines, the ends of the skein of material are connected to each other and the material assumes the form of an endless skein or rope which is supported and moved by the skein-winder, passing through the dyeing bath a predetermined number of times.

It is also known to provide in various parts of the tub inlet and outlet conduits for the dyeing liquid, and conduits for introducing fluid (for example air and/or steam) into the bath to produce turbulence, in order to facilitate the movement of the skein and to improve its contact with the treatment agents contained in the bath. For the same purpose the transverse section of the interior of the tubular tub is generally irregular.

The above-mentioned known expedients in dyeing machines tend to interfere with the tortuous path of the skein of material, obstructing its movement. This, added to the fact that the skein of material is by nature prone to entanglement, especially when it encounters one or more obstacles, gives rise to several technical difficulties in dyeing machines, until now not satisfactorily resolved. One of these technical difficulties is the fact that the material, in passing through the dyeing or finishing bath, for the above-mentioned reasons, can become arrested. Such stoppage of the material is not easily detected, as the skein-winder continues to rotate while the skein of material slides over it. A stoppage of the material in the dyeing bath, even for short periods, can ruin the material irreparably.

A main object of this invention is to provide an apparatus which controls with safety the movement of piece goods in dyeing and/or finishing machines, in particular in machines for dyeing skeins of material, and which can detect the occurrence of a stoppage of the skein material during its movement through the dyeing and finishing bath even if the means drawing the skeins through the bath continue to function.

A further object of the invention is to provide an apparatus of said type having simple structural and functional characteristics, susceptible of a wide application to dyeing and/or finishing machines without entailing specific time-consuming modifications or adaptations of the dyeing machines. Another object of the invention is to provide an apparatus of the said type which is of simple realisation, allowing the use of material normally available commercially.

According to the invention there is provided an apparatus for controlling the movement of piece goods in a dyeing and finishing machine, in particular for controlling the movement of a skein of material in a dyeing machine, in which the skein is moved in a closed circuit including at least partly tubular conduits by skein-winding means, the said control apparatus comprising at least one device adapted to provide upon movement of the skein electrical and/or electromagnetic pulses, said device being associated with the skein in at least one point of its overall length, a device for detecting said pulses, located externally of one of the conduits of said dyeing machine in at least one zone of the closed circuit of movement of the skein, and a signalling device adapted to be operated by the detected pulses in the event of stoppage of the skein.

The invention will now be described, by way of non-limiting example, with reference to the accompanying drawings, in which:

FIG. 1 represents schematically a machine for dyeing material in the form of a skein incorporating apparatus according to one embodiment of the present invention for controlling the movement of the material;

FIG. 2 represents, on enlarged scale, a detail of the control apparatus according to the invention, as employed in the machine of FIG. 1, and

FIG. 3 represents schematically part of a second embodiment of apparatus according to the invention for controlling the movement of a skein of material through a dyeing machine.

FIG. 1 illustrates a machine for dyeing material in the form of a skein, comprising essentially a tubular U-shaped tub 1 having tubular legs 2 and 3 the upper ends of which are in communication with the inside of a cylindrical chamber 4 having a charging door 4a. A rotary skein-winder 5 driven by a motor 5a through a transmission belt 5b is mounted in the chamber 4. The legs 2 and 3 together with the chamber 4 define a closed path for the skein of material to be dyed.

The tub 1 is supported on a base and is filled to a certain level 6a with a liquid forming a dyeing and finishing bath 6. The skein-winder 5, of known type, supports and pulls the skein 7 of material and has an essentially elliptical shape. Upon rotation the winder 5 pushes and pulls the skein 7 at a cyclically varying speed so that the skein passes through the bath 6 in a tortuous conformation, shown schematically in FIG. 1 as a number of bends 7a.

The apparatus of this invention for controlling the movement of the skein 7 through the bath 6 and for detecting stoppages in such movement, comprises a pulse generator 8 associated with the skein 7 and a pulse detector device 9 arranged externally of the tub 1 for the purpose of detecting the pulses generated by the generator 8.

More particularly according to a preferred embodiment of the invention, illustrated in FIGS. 1 and 2, the pulse generator 8 comprises a permanent magnet attached to the skein 7, while the pulse detector device 9 is formed (FIG. 2) by a number of ferromagnetic cores 10, on each of which an electrical conductor is wound to form a coil 11, the coils 11 being connected in series. The ferromagnetic cores 10 are mounted on and arranged with their axes extending radially outwardly from an annular collar 12 which is clamped by means of screws 13 to the tubular leg 2 of the tub 1. The two ends 14 and 15 of the series-connected coils 11 are electrically connected to a signalling or warning device 16 including, for example, an acoustic alarm 17.

The operation of the control apparatus according to the invention is as follows: when the permanent magnet 8, which moves cyclically with the skein 7, passes through the zone of the detector device 9, it induces an electromotive force in the coils 11 and the resulting induced current flows in signalling device 16. The device 16 is provided with a delay circuit which causes the associated alarm 17 to operate only if the interval between two successive pulses from the detector device 9 exceeds by a predetermined time "t" the time T taken by the skein 7 to accomplish a complete circuit of the closed path of the machine. For example, if it takes a minute for the skein 7 to accomplish a complete circuit under normal conditions of operation of the machine, the delay circuit of the signalling device 16 may be set to provide a delay of 1.5 minutes. In the event of an accidental stoppage of the skein 7 within the dyeing and finishing bath 6 the permanent magnet 8 stops and therefore ceases to induce regular current pulses in the detector device 9 so that the signalling device 16 ceases to receive pulses. If this stoppage lasts for a time exceeding the predetermined delay (e.g. 1.5 minutes) of the delay circuit of the signalling device 16, the alarm 17 operates and the machine operator can quickly intervene to eliminate the cause of the stoppage, thereby avoiding prolonged immersion of the arrested skein of material in the bath 6, which would damage the material.

In the second embodiment illustrated in FIG. 3, the apparatus according to this invention comprises a high frequency voltage generator 18 connected, through leads 19 and 20, to a winding 21 having one or more turns surrounding the skein 7 for example at a point on the leg 2 of the tub 1.

One of the leads, for example the lead 20, includes a detecting device 22 which is connected through leads 23 and 24 to a signalling device 25 including, for example, an acoustic alarm 25a.

The apparatus further includes a metal element 26, not necessarily magnetic, which is fixed to the skein 7 of material being treated in the machine which passes cyclically through the leg 2. The detecting device 22 is provided with a known circuit which is responsive to the electromagnetic characteristics of the winding 21 surrounding the leg 2 at the frequency of the oscillating voltage applied to the winding 21 and generates pulses only upon the passing of the metal element 26 through the winding 21. These pulses are sent to the signalling device 25 which operates the alarm 25a when the detected movement of the skein 7 is irregular. The signalling device 25 is, as in the previously described embodiment, provided with a known delay circuit. If the pulses are detected at intervals T, substantially equal to the time taken by the skein 7, and therefore by the metal element 26, to accomplish a complete circuit, the device 25 prevents the acoustic alarm 25 from functioning; on the other hand, if the interval between two successive detected pulses exceeds by an interval "t" the time T taken by the skein 7 to accomplish a complete circuit in the machine when the latter is functioning normally, the acoustic alarm 25a is automatically operated by the device 25 to warn the machine operator.

It will be appreciated that instead of an acoustic alarm 25a the signalling device 25 could be associated with an optical warning device.

Claims

I claim:

1. In a dyeing and finishing machine of the kind having a closed circuit including at least partly tubular conduits and skein-winding means for moving a skein of material through a bath in said closed circuit, improved control apparatus comprising at least one device adapted to provide upon movement of the skein electrical and/or electromagnetic pulses, said device being associated with the skein in at least one point of its overall length, a device for detecting said pulses, located externally of one of said conduits of said dyeing machine in at least one zone of said closed circuit of movement of the skein, and a signalling device adapted to be operated by the detected pulses in the event of stoppage of the skein.

2. Apparatus as defined in claim 1, wherein said device for providing electrical and/or electromagnetic pulses is formed by a permanent magnet which in use of the apparatus is arranged for movement with the skein.

3. Apparatus as defined in claim 1, wherein said pulse detecting device comprises at least one coil wound around a zone of at least one of said conduits defining said closed circuit of movement of the skein, and therefore of said device for providing the electrical and/or electromagnetic pulses.

4. Apparatus as defined in claim 1, wherein said pulse detecting device comprises a number of ferromagnetic cores and a respective coil wound on each said core, said coils being connected together in series and the series-connected coils being connected to said signalling device.

5. Apparatus as defined in claim 4, including an annular support arranged externally of said zone of at least one of said conduits defining said closed circuit of the skein material, said ferromagnetic cores being mounted on said annular support with their axes extending radially outwardly from said support.

6. Apparatus for controlling the movement of piece goods in a dyeing and finishing machine, in particular for controlling the movement of a skein of material in a dyeing machine having means for moving the skein cyclically in a closed circuit closed within conduits which are at least partly tubular, said apparatus comprising: an electrically conductive element which in use of the apparatus is associated with a point on said skein; an electrically conductive winding surrounding a zone of at least one of the said conduits of the machine; a generator of an oscillatory voltage at a predetermined frequency connected to said winding; a detecting device connected to the winding and to the said generator, said detecting device being adapted to provide an electrical pulse each time the conductive element passes through the said zone surrounded by the winding; and a signalling device connected to said detecting device and operable in response to variation or cessation of said pulses resulting from stoppage of the skein in the machine.

7. Apparatus as defined in claim 1 wherein said signalling device includes an alarm and a delay circuit which operates said alarm when the interval between two successive pulses from said detecting device exceeds by a given interval "t" the time "T" taken by the skein to complete its closed circuit under normal operating conditions of the machine.

8. Apparatus as defined in claim 6, wherein said signalling device includes an alarm and a delay circuit which operates said alarm when the interval between two successive pulses from said detecting device exceeds by a given interval "t" the time "T" taken by the skein to complete its closed circuit under normal operating conditions of the machine.