GB2130256A - Winding mechanism for multiphase weaving machines - Google Patents

Abstract

A winding mechanism for a weaving machine having weft inserters (1) preferably arranged around a rotatable table, each weft inserter has a spool (2) above which is mounted an electromagnet (18); the spool is arranged to be acted on for winding by fluid pressure which rotates the spool by means of turbine blades 17; the spool is normally braked to the inserter by a plate 22 at the winding station but is unbraked by means of the electromagnet and may be further unbraked by the action of the fluid pressure lifting the spool off a braking seating in the inserter; weft thread is guided to the spool by a guide preferably a tube (24). <IMAGE>

Description

SPECIFICATION Winding mechanism for multiphase weaving machines The present invention relates to a winding mechanism for a multiphase weaving machine.

At present, several types of winding mechanisms are used for forming a measured weft supply in multiphase weaving machines. One of those mechanisms comprises a winding head with a spindle adapted for receiving the spool of the weft inserter. The winding head is provided with grippers, of which the jaws guide the weft thread from the supply bobbin via the weft inserter spool. The cap of the winding head bears thereupon against the weft inserter spool, thus gripping the weft and displacing it by its overset projection into a groove in the weft inserter spool, thus making possible its winding.The drive of the spindle is derived from a high speed belt via take off rollers and is provided with a brake, a clutch and a timing mechanism, which makes possible the disengagement of the clutch and the engagement of the brake after an exact time interval, which corresponds to the required number of revolutions of the weft inserter spool. The winding mechanism comprises further adjusting elements, which make possible the complementary measurement of the necessary weft length.

The disadvantage of the winding mechanism of that type consists in its relatively considerable intricacy and the undesired wear of certain winding elements, as e.g. the weft inserter spools, the cap, and the take off roller. Due to the wear, it is difficult to maintain a constant accuracy in measuring the length of the weft to be wound. Due to the considerable mass of the whole mechanism, its operation is very noisy.

The known mechanism as specified above is usually provided with an electromagnetic clutch and a brake, which mitigate certain disadvantages of the mechanical embodiment, however, in this case arises the problem of low reliability of certain electric elements.

In certain mechanisms, winding by means of a wing is used, which also mitigates a part of the disadvantages encountered when using the cap however, the removal of the weft inserter spool from the winding head becomes more complicated, and requires the wing to be directed always in the same position.

Another winding mechanism is also known, in which the weft is blown by an air flow into the blowing-in chamber of the weft inserter.

The disadvantage of this arrangement is an uncontrolled deposition of the weft in the blowing-in chamber, which causes an irregular weft distribution along the total length of the shed. Moreover, the feeding of pressure air to the winding mechanism and the weaving machine is very unfavourable.

A winding mechanism according to the present invention is characterised in that electromagnets are situated above the rotatable table, of which each is provided with a plotter and a compression spring for pressing the plotter against the front part of the weft inserter spool, and further a guiding tube for introducing the weft end into an annular space at the bottom of the spool, a suction tube connected to an underpressure source being arranged below the rotatable table, when said spool is provided in its bottom with a system of radial openings and a small blade type turbine adjacent to the bottom, which is mounted, together with the spool on a pin anchored in a diaphragm with suction openings, which is fixed in the continuous opening of the weft inserter.

A weft inserter having a winding mechanism according to the invention comprises a spool for a length of weft thread, rotatably mounted to the inserter, an electromagnet mounted adjacent the spool, a braking member biased to brake the spool and actuatable by the electromagnet so as to unbrake the spool, means for guiding the thread onto the spool, the spool being rotatable so as to wind the thread onto it by fluid pressure means.

The advantage of the winding mechanism according to the present invention consists in its relative simplicity of design, a low noise level due to low rotating masses, and fail-safe operation. The winding mechanism makes possible the reliable winding of an exactly defined length of weft thread.

Embodiments of the winding mechanism according to the present invention in form of example are represented in the accompanying drawings, of which Figure 1represents an axial section through one unit of the winding mechanism in the first embodiment: Figure 2-an axial section through one operation unit of the winding mechanism in the second embodiment; and Figure San axial section through one operation unit of the winding mechanism in the third embodiment.

The winding mechanism for multiphase weaving machines consists of a not represented rotatable table, which is provided with seats (not shown) for depositing the weft inserters 1 (Fig. 1), of which each is provided with a spool 2 mounted freely rotatably in its continuous opening 3. Spool 2 is mounted by its hub 4 on bearings 5, which are provided on pin 6, which is fixed to diaphragm 7, provided with suction openings 8. Diaphragm 7 is fixed, by means of ring 9 and screws (not represented) via a resilient washer 10 into a recess 11 in the continuous opening 3. Spool 2 is provided with a circumferential groove 12, of which one side wall 1 3 extends and meshes between the diaphragm 7 and the stop shoulder 1 4 in the continuous opening 3.The bottom 1 5 of circumferential groove 1 2 is provided with a system of radial openings 1 6 which open into the space between the bottom 1 5 of circumferential groove 1 2 and hub 4 of spool 2, in which space a number of blades is arranged, which form a small blade type turbine 1 7.

In the rotatable table (not represented) is mounted, in each of its seats, an electromagnet 1 8 with winding 19, adjustable as to height. The electromagnet 1 8 is provided with an axial recess 20, in which a compression spring 21 is anchored, to the opposite end of which is mounted plotter 22, which bears (Fig. 1) against the front part of spool 2, thus covering the small blade type turbine 1 7.

Oppositely to electromagnet 18, a sucking nozzle 23, connected to an underpressure (that is pressure lower than ambient pressure) source (not represented), is arranged adjustable as to its height. Oppositely to the circumferential groove 1 2 of spool 2, a recess is made in the weft inserter 1, into which engages the guiding tube 24 for weft thread 25.

The guiding tube 24 goes as far as the annular space 26 around spool 2, which is connected around electromagnet 1 8 to the surrounding environment by an annular opening 27.

The arrangement of the winding mechanism as represented in Fig. 2 is fundamentally the same as the arrangement in Fig. 1. The pin 6 in this embodiment passes through hub 4 of spool 2 and is provided with a spherical end for contact with the elastic stop 28, which is mounted to the central projection 29 of electromagnet 18. Around the central projection 29, compression spring 21 is arranged, which bears against an annularly adapted supporting projection 30 on an annularly formed plotter 22, which in Fig. 2 bears again against the front part of spool 2.Plotter 22 is bent in this case, at its outer edge, in the upward direction, and is provided thereon with circumferential projections 31 which engage guiding projections 32 on the circumference of electromagnet 1 8. The annular opening 27 around electromagnet 1 8 engages the annular space 26 around spool 2 of the guiding tube 24 for weft thread 25.

The winding mechanism as shown in Fig. 3 is made again on the same principle. Spool 2 is provided in this embodiment with a bottom 1 5 directed towards hub 4. The annular space 26, into which the guiding tube 24 is introduced, is arranged between bottom 1 5 and hub 4 of spool 2. On the circumferential side of spool 2, the small blade type turbine 1 7 is arranged. Spool 2 is secured against removal from the upper surface of weft inserter 1 by the stop shoulder 14, engaging the small blade type turbine 17.Electromagnet 18 is provided with a central opening 33, through which passes guiding tube 24, and which forms, on the other hand, an air channel for the air sucked via the small blade type turbine 1 7. The central opening 33 is provided, from the side of spool 2, with an annular step 34, F in which is deposited compression spring 21, bearing with one of its ends against an annu larly adapted supporting projection 30 on an annularly formed plotter 22.

The winding mechanism according to the present invention operates as follows: The weft inserter 1, upon known passage through the shed of a multiphase weaving machine, during which the weft thread from its spool 2 was unwound, is deposited in a not represented seat of the rotatable table.

From the upper side, electromagnet 1 8 is approached to spool 2 by a not represented moving mechanism, and from below suction nozzle 23. Simultaneously, guiding tube 24 with weft thread 25, a supply of which is wound on a not represented cross wound bobbin, penetrates the annular space 26 of spool 2. By means of suction nozzle 23, spool 2 of weft inserter 1 and plotter 22 are acted upon by underpressure. This underpressure acts simultanously also upon weft thread 25 through suction openings 8 in diaphragm 7, small blade type turbine 1 7 and via radial openings 16 in the bottom 1 5 of spool 2.By the action of this underpressure, the end of weft thread 25 is displaced from guiding tube 24 for a defined length corresponding to its need and secured by a not represented mechanism. The underpressure acting upon plotter 22 causes the latter to be pressed against spool 2, thus securing its initial posi tion before winding. The underpressure effect is stiil increased by the action of compression spring 21. At a certain moment, a sensor (not represented) emits a signal for the electronic control device of electromagnet 18, whereu pon the latter attracts plotter 22 against the action of compression spring 21. Thus, the brake on spool 2 is released and simultane ously, the air supply to the small blade type turbine 1 7 is opened, which starts its rotary motion caused by the air flow.Thus, weft thread 25 is wound on to spool 2. During this winding, diaphragm 7 is bent by the force effect thus caused, and thereby, spool 2 is removed with its side wall 1 3 in the embodi ment represented in Figs. 1 and 2, or the part of the small blade type turbine 1 7 in the embodiment as represented in Fig. 3, from the the stop shoulder 14. Thus, spool 2 is com- pletely released from any braking action, the winding thus taking place with only minimum passive resistance, resulting only from the rolling deposition of spool 2. After a certain time or after a certain number of revolutions of spool 2, the feeding of the winding 1 9 of electromagnet 18 is interrupted, plotter 22 is pressed by action of compression spring 21 and underpressure against spool 2, which is thereby stopped.

Upon winding a length of the weft thread 25 necessary for one fabric width, weft inserter 1 with spool 2 are prepared for insertion into the shed.

The present invention can be used for winding weft thread into weft inserters of multiphase weaving machines.

Claims (7)

1. A winding mechanism in a weaving machine having a rotatable table with seats for -weft inserters having spools for a measured weft thread length, wherein above said rotatable table electromagnets are arranged, of which each is provided with a plotter and a compression spring for pressing the plotter against the spool; a guiding tube being provided for introducing the end of weft thread into an annular space around the spool, a suction nozzle connectable to an under pressure source being arranged below the rotatable table, the spool being provided with radial openings between its exterior and interior and a turbine in the interior, the turbine and spool being mounted rotatably, on a pin mounted in turn on a diaphragm having suction openings allowing fluid to pass from the turbine to the nozzle, the diaphragm being fixed in an opening of the weft inserter.

2. A weft inserter having a winding mechanism, the mechanism comprising a spool for a length of weft thread, rotatably mounted to the inserter, an electromagnet mounted adjacent the spool, a braking member biased to- brake the spool and actuatable by the electromagnet so as to unbrake the spool, means for guiding the thread onto the spool, the spool being rotatable so as to wind the thread onto it by fluid pressure means.

3. A weft inserter as claimed in Claim 2 wherein the spool is mounted to a resilient member so that fluid pressure acting on the spool causes it to move axially off a braking seating on the inserter.

4. A multiphase weaving machine having the weft inserter winding mechanism of Claims 2 or 3.

5. A winding mechanism for a weaving machine substantially as described with reference to Fig. 1 of the accompanying drawings.

6. A winding mechanism for a weaving machine substantially as described with reference to Fig, 2 of the accompanying drawings.

7. A winding mechanism for a weaving machine substantially as described with reference to Fig. 3 of the accompanying drawings.