Device for automatic replacement of the cloth beam in weaving looms

Abstract: A device for automatic replacement of the cloth beam (1) in a weaving loom, of the type in which the cloth beam (1) is supported and driven by a pair of driving cylinders (2,3) on which it rests, comprises a pair of cradle arms (6) for supporting a standby cloth roller (1R), automatic means for cutting the fabric, means (9,17) for guiding the edge of the cut fabric around said standby cloth roller (1R) and means for causing rotation of said roller (1R), said cradle arms (6) oscillating between a first position in which said standby roller (1R) is located alongside the cloth beam (1) and a second position in which said roller (1R) comes to rest on said driving cylinders (2,3).

Description: The present invention relates to a device for automatic replacement of the cloth beam in weaving looms. In particular the invention relates to a device which allows the cloth to be cut automatically when the cloth beam has reached the desired dimensions and said beam to be replaced with a new roller, with winding of the free edge of the new cloth being formed thereon. The device according to the present invention allows the abovementioned operations to be performed without having to interrupt the normal operation of the loom and may be applied successfully both to horizontal looms and to vertically extending looms which therefore have the cloth beam in the top part of the loom itself. It is well known to all operators in the sector that the operation of replacing the cloth beam is a time-consuming operation. The operator, in fact, after cutting the fabric being formed with a manual or automatic cutter, must remove the full beam and then insert and fix an empty roller in the position previously occupied by the removed roller and finally start up the loom again if it has previously been stopped and then monitor operation of the latter until a sufficient quantity of fabric has been wound onto the new roller to ensure good grip thereof on the roller and hence a correct winding action. Document BE 1 000 684 A describes a device classically used for beam replacement. The operations of removing the full cloth beams, in view of their considerable size and weight, are performed by means of a self-propelled truck or - only in the case of vertical looms - by means of a bridge crane. In both cases, therefore, normally one or at the most two mechanical transportation means are available for an entire weaving room. The time strictly required for the replacement operation involves an operator being kept busy for at least 5 minutes, to which the time for travel from the loom to the warehouse and vice versa must be added. If then, as often happens, in the same weaving room more than one loom reaches simultaneously the maximum diameter permitted by the cloth beam, the loom must be stopped and the intervention times increase considerably since the transportation means must be allowed the time to leave the room in order to deposit the beam which has just been picked up and then position itself again on the loom which has finished working. This therefore results in stoppage time of the looms, with a consequent damaging effect on the overall productivity of the weaving room. One object of the present invention is to overcome this drawback by providing a device which is able to perform automatically replacement of the cloth beam with a new roller which, for this operation, does not require action on the part of any operator, except for removal of the full cloth beam. Another particularly important object of the present invention is that of allowing the entire operation of replacement of the cloth beam to be performed without even minimum stoppage of the loom, which is thus able to maintain unchanged its full production output. A further object of the present invention is that of providing an automatic device for replacement of the cloth which allows, where necessary, the operation of picking up of the full cloth beam to be delayed considerably with respect to the moment when it becomes full, for example for up to 30 minutes, without requiring either action on the part of an operator or interruption of the loom operation. A last object of the present invention, finally, is that of allowing the operation of replenishing of the loom with the new roller to be performed during a time period different from that in which replacement of the cloth beam takes place, thus allowing optimization of the operator intervention time. The aforementioned objects, together with still further objects, are achieved, according to the present invention, by a device for automatic replacement of the cloth beam in a weaving loom according to claim 1, of the type in which the cloth beam is supported and driven by a pair of cylinders on which it rests with its peripheral surface, characterized in that it comprises a pair of cradle arms for supporting an empty standby roller, automatic means for cutting the fabric, means for guiding the edge of the cut fabric around said standby cloth roller and means for causing rotation of said roller, said cradle arms oscillating between a first position in which said standby roller is located alongside the cloth beam and a second position in which said roller is free to position itself so as to rest on said driving cylinders. The invention, however, will now be described more clearly in detail, with reference to the accompanying figures, which show a preferred embodiment thereof, suitable for application to a vertical loom, in which: Fig. 1 is a schematic side view of the device for automatic replacement of the cloth beam according to the present invention; Fig. 2 is a front axonometric view of the same device; Fig. 3 is a view, on a larger scale, of the left-hand part of Fig. 2 which shows the device for automatically cutting the fabric; Fig. 4 is a plan view of the automatic cutting device alone; and Fig. 5 is a view similar to that of Fig. 1 which illustrates the movement of the cradle arms 6 for transferring the standby roller into the ordinary working position. The general arrangement of the parts of the loom affected by the device according to the present invention can be clearly seen in Figs. 1 and 2. These drawings, in fact, show the cloth beam 1 which rests on the pair of cylinders 2 and 3, respectively called a roll-pushing cylinder and a roll-winding cylinder, which perform and control winding thereof. For this purpose the two cylinders 2 and 3 are operated by the cloth-pulling cylinder 4, via the toothed chain 5, in accordance with the arrangement already described in WO97/13899 in the name of the same Applicant. The device for automatic replacement of the cloth beam according to the present invention is arranged in this zone of the loom, namely in a lateral position with respect to the cloth beam 1 and the roll-winding cylinder 3. This device consists of several cooperating parts, namely: means for supporting and moving a standby roller; means for guiding and cutting the fabric; means for guiding and winding the new free edge of the fabric around said standby roller. These means will be described separately and in detail below. The means supporting and moving the standby roller 1R consist of a pair of cradle arms 6 arranged at the two ends of the loom, at a distance such as to be able to receive between them the standby roller 1R which rests with its central pin inside the free cradle-shaped ends 7 of the arms. Said arms 6 are pivotably mounted in a central position on a common axis which, in the embodiment shown, coincides for the sake of constructional convenience with that of the roll-winding cylinder 3. The ends of the arms 6 opposite to the cradle-shaped ends 7 are operated by two corresponding cylinder-and-piston units 8, which are preferably pneumatically operated, between a standby position 6A and a loading position 6C which can be clearly seen in Fig. 5. The shape of the cradle arms 6 is such that, in the loading position 6C, they form a slightly inclined support surface for the pin of the roller 1R so as to allow disengagement of the roller IR from the arms 6 simply by means of the force of gravity, as will be explained more clearly below. The means for guiding and cutting the fabric consist of a rectangular guide bar 9 with rounded edges, arranged immediately downstream of the roll-winding roller 3 and able to cause deviation of the path of the fabric being formed, away from the cloth beam 1 and towards the standby roller 1R, as can be clearly seen in Fig. 1. The guide bar 9 accommodates internally the fabric cutting means which can be seen more clearly in Figs. 2, 3 and 4 and which consist of a carriage 10 sliding on the guide 9 and carrying a fixed triangular cutter 11 and a rotary blade 12. The movement is imparted to the carriage 10 by an electric or pneumatic motor 13 via a belt 14 which extends in annular fashion across the whole width of the loom and has its ends fixed to the two sides of the carriage 10. The rotary movement for the rotary blade 12 is obtained by means of engagement of a gearwheel 15, which is fixed thereto and coaxial therewith, with a rectilinear rack 16 contained inside the guide bar 9. The arrangement of the fixed cutter 11 is such that its free end emerges from the edge of the guide bar 9 on which the fabric T rests. The means for guiding and winding the free edge of the fabric T around the standby roller 1R consist of a first series of fixed belt units 17 and a second series of oscillating belt units 18 which are suitable for controlling winding of the fabric T in the bottom part and in the upper part of the roller 1R, respectively. The belt units 17 extend between a rotating transverse shaft 19 which imparts movement to them and transmission bushes 21 mounted idle on a fixed shaft 20 so that the respective toothed belts 22 adhere elastically to the bottom part of the roller 1R. The belt units 18 are arranged between the same bushes 20 onto which the belts 22 engage, from which therefore they receive movement, and transmission bearings 23 fixed to the shaft 20 by means of rigid brackets 24. The shaft 20 - and together with them the brackets 24, the bearings 23 and hence the belt units 18 - are able to oscillate between a working position 23L and a rest position 23R (Fig. 5) as a result of the action of acylinder-and-piston unit 26. In the working position 23L the belts 25 of the units 18 adhere elastically to the upper surface of the standby roller 1R, in a manner entirely similar to that already seen for the belts 22 of the units 17. Operation of the device for automatic replacement of the cloth beam according to the present invention will now be briefly described. During operation of the loom, the fabric T supplied from the weaving zone passes, in an entirely conventional manner, across the cloth-pulling cylinder 4 and from here reaches the roll-winding cylinder 3. When the point of contact between the cylinder 3 and the cloth beam 1 is reached, the fabric T no longer rests, following its usual path, in contact with the surface of the beam 1, but is deviated onto the bar 9 and then returns back onto the beam 1. In this way the fabric T is always kept in close contact and properly tensioned against the side edge of the bar 9 from which the triangular cutter 11 of the cutting device projects. When the beam 1 has taken up the desired length of fabric, the cutting device is activated by operating the electric motor 13. Owing to the action of the endless belt 14 the cutting unit - formed by the carriage 10, the fixed cutter 11 and the rotary blade 12 - is rapidly displaced from one side to the other of the loom; during displacement the triangular cutter 11 grips the tensioned fabric and displaces it towards the inside of the bar until it is close to the rotary blade 12 where the fabric is cut with the maximum precision. To ensure a greater cutting quality, the rotary blade 12 has a polygonal shape in plan view, as can be seen in Fig. 3. Once the fabric has been cut, the cutting device is brought back into the rest position, while the tail end of the fabric is wound onto the beam 1 which continues to rotate about itself as a result of the action of the cylinders 2 and 3, until it is removed by a special bridge crane or truck and transferred to the packaging and despatch department. During this stage, it is obviously possible to arrange automatically beam fastening straps around the peripheral surface of said beam, without affecting at all the movement of the free end of the fabric. The latter, in fact, as soon as the cutting operation has been performed, falls as a result of gravity onto a special support surface 27 and advances on the latter until it is gripped between the standby roller 1R and the first series of belt units 17. At this point the fabric T is drawn during the movement imparted to the roller 1R by the belt units 17 and 18, remaining adherent to the surface of the roller partly owing to the action of the belts 22 and 25, within the rising semi-circle of the roller 1R, and partly owing to its own weight within the descending semi-circle of the roller 1R. The newly formed fabric therefore starts to be wound uniformly onto the replacement roller 1R, while the latter is in a lateral position - with respect to the ordinary position still occupied by the full cloth beam 1 - determined by the cradle arms in the position 6A shown in Fig. 5. The elasticity of the belts 22 and 25 and the possibility of performing gradual clockwise movement of the shaft 20, preferably in contrast with spring means, as winding of the fabric T onto the roller 1R proceeds, allows the weaving operation to be continued, keeping the roller 1R in this position even for very long periods of time, which can vary depending on the type of fabric being processed, but which are generally longer than at least 30 minutes. The operator therefore has a considerable amount of time available to plan carefully the operation of removing the full cloth beams 1 from the various working looms, avoiding any undesirable stoppage of the looms, since operation continues undisturbed with winding of the fabric onto the rollers 1R in the standby position. As soon as the cloth beam 1 has been removed from the loom, the operator performs displacement of the arms 6 which are displaced from the position 6A into the position 6C - an operation, this, which can obviously also be performed automatically by the control panel of the carriage or the bridge crane. In this position, the roller 1R is subjected on the one hand to the force of gravity, which pushes it along the inclined surface in the direction of the cylinders 2 and 3, while on the other hand it is retained by the fabric T which exerts a pulling force in the direction of the arrow F according to Fig. 5. The pulling force exerted by the fabric T therefore prevents the roller 1R from sliding with excessive speed along the inclined surface formed by the arm 6 in the position 6C and allows it to come into contact in a sufficiently gentle manner with the cylinder 2 and therefore - after the arm 6 has been brought again into the position 6A - into contact with the cylinder 3, The cylinder 1R has thus occupied its ordinary operating position, without the loom weaving operations or the fabric winding operations having been interrupted at all, providing moreover the operator with a long time during which to plan, more carefully and efficiently, removal of the full cloth beam, thus achieving the main objects of the invention. Replenishing of the loom with the empty replacement roller may therefore be performed at any time during winding of the cloth beam 1, since this operation merely requires positioning of the roller 1R on the cradle-shaped ends 7 of the arms 6. It is obvious, therefore, that, from this point of view as well, the desired objects of the invention have been achieved. The device for automatic replacement of the warp beam according to the present invention has been described with reference to a particular preferred embodiment, but it is obvious that the protective scope thereof is not limited to this, but comprises all the possible variants which may occur to a person skilled in the art, within the scope of the claims indicated below.

Claims: Device for automatic replacement of the cloth beam in a weaving loom, of the type in which the cloth beam (1) is supported and driven by a pair of cylinders (2,3) on which it rests with its peripheral surface, characterised in that it comprises a pair of cradle arms (6) arranged on the two sides of the loom for supporting a standby cloth roller (1R) arranged parallel to the cloth beam (1), automatic means (9-12) for cutting the fabric (T), means (27, 22, 25) for guiding the edge of the cut fabric (T) around said standby roller (1R) and means (17, 18) for causing rotation of said roller (1R), said cradle arms (6) being hinged centrally on an axis parallel to the axis of said standby roller to oscillate in planes perpendicular to the axis of the roller between a first position in which said standby roller (1R) is located alongside the cloth beam (1) and in which the initial winding of the fabric (T) can take place, and a second position in which said roller is free to position itself so as to rest on said driving cylinders (2, 3). Device as in claim 1, wherein said cradle arms (6) have free cradle-shaped ends (7) on which the ends of the axial pin of said standby roller (1R) rest. Device as claimed in claim 2, wherein the oscillation of said cradle arms (6) is driven by cylinder-and-piston means (8) acting on their ends opposite to said cradle-shaped ends (7). Device as claimed in claim 1, wherein the axis on which said cradle arm (6) are hinged coincides with the axis of one (3) of the driving cylinders (2, 3) of the cloth beam (1). Device as claimed in claim 1, wherein said means for automatically cutting the fabric comprise a cross-bar (9) which extends over the entire width of the loom and on one edge of which the path of the fabric (T) being fed to the cloth beam (1) is deviated away from said beam and towards said standby roller (1R), and a device (10-12) for cutting the fabric (T), slidable along said edge. Device as claimed in claim 5, wherein said cutting device is housed inside said bar (9) and comprises a fixed triangular cutter (11), the tip of which emerges from the edge of the bar (9) on which the fabric (T) is deviated, and a rotary blade (12) cooperating with said cutter (11). Device as claimed in claim 6, wherein said cutting device is mounted on a carriage (10) movable along a guide extending longitudinally along said bar (9) and drawn thereon by an endless belt (14) driven by an electric or pneumatic motor (13). Device as claimed in claim 7, wherein said rotary blade (12) is fixed to a gearwheel (15) coaxial therewith, said gearwheel meshing with a rack-type profiled part (16) extending longitudinally along said bar. Device as claimed in any one of claims 6 to 8, wherein said rotary blade (12) has a polygonal profile. Device as claimed in claim 1, wherein said means for guiding the edge of the cut fabric (T) around the standby roller (1R) and said means for causing rotation of the standby roller consist of a plurality of belt units arranged in contact with the rising semi-cylinder of said roller (1R). Device as claimed in claim 10, wherein said belt units comprise lower fixed or elastically fixed units (17) and upper units (18) movable between one or more working positions in which said units are in contact with the lateral surface of roller (1R), and a rest position in which said units (18) are made to move away from the surface of the roller (1R). Device as claimed in any one of claims 5 to 11, wherein an inclined plate (27) for accompanying the free edge of the fabric (T) immediately after the cutting operation is arranged between the edge of said bar (9) which deviates the fabric (T) and the bottom part of said standby roller (1R). Device as claimed in any one of the preceding claims, wherein said standby roller (1R), in said first position, has a capacity for taking up fabric equivalent to at least 30 minutes' operation of the loom.

Inventors: GENDELMAN MIKHAIL, GENDELMAN, MIKHAIL
Applicants: PROMATECH SPA, PROMATECH S.P.A.
Application year: 1998
Main classification: D03J1
IPC codes: D03J1