PAPER MILL REWINDER WITH CONTINUOUS REEL CHANGE DEVICE

Abstract

The invention pertains to the field of industrial machinery for converting paper and/or for processing strip materials, and relates to a paper mill rewinder for forming reels of paper strip material, in particular, but not exclusively, tissue paper, of conventional or structured type, non-woven, TAD (Through Air Drying), or other similar materials characterized by having a very light weight and low density, with continuous, or non-stop, reel change device. Said rewinder (1) comprises: a supporting frame (3); feed means (4) for a winding rod (A); a main forming cradle (C1) for a reel (B) around said winding rod (A), comprising a first (5) and a second (6) winding roller; means for unloading (7) said reel (B) once formed; a control unit, a secondary pre-forming cradle (C2) for said reel (B), comprising a third winder roller (8) and lateral supporting means for said reel (B); means for transferring said reel (B) from said secondary pre-forming cradle (C2) to said main forming cradle (C1), where said transfer takes place without interruption to the winding, of the strip (N) onto said rod (A).

Claims

1. Paper mill rewinder (1) for forming reels (B) of paper strip material (N) around a winding rod (A), the ends of which are provided with two spindles (2′, 2″), where said rewinder (1) comprises: a supporting frame (3); feed means (4) for a winding rod (A); a main forming cradle (C1) for a reel (B) around said winding rod (A), comprising a first (5) and a second (6) winding roller; means for unloading (7) said reel (B) once formed; a control unit, wherein it comprises: a secondary pre-forming cradle (C2) for said reel (B), comprising a third winder roller (8) and lateral supporting means for said reel (B); means for transferring said reel (B) from said secondary pre-forming cradle (C2) to said main forming cradle (C1), where said transfer takes place without interruption to the winding of the strip (N) onto said rod (A).

2. Rewinder (1) according to claim 1 wherein it comprises: first motor means (M1) adapted to cooperate with said spindles (2′, 2″) and to impart a rotation movement to said winding rod (A) inside said secondary cradle (C2); gripping means (9′, 9″) adapted to cooperate idly with said spindles (2′, 2″) and to support said winding rod (A) above said main cradle (C1), where the cooperation between said motor means (M1) and said gripping means (9′, 9″) with said spindles (2′, 2″) makes it possible to never abandon the reel (B) in all forming phases.

3. Rewinder (1) according to claim 1, wherein said transfer means comprise: a pair of supporting and moving arms (10′, 10″) for said reel (B), adapted to provide said lateral support for said secondary cradle (C2) in order to support said reel (B) during the pre-forming phase by keeping it always in contact with said third winding roller (8) and then to transfer said reel (B) into said main cradle (C1), second motor means (M2) adapted to impart an oscillating movement to said pair of supporting and moving arms (10′, 10″).

4. Rewinder (1) according to claim 3, wherein said transfer means comprise a (11) placed between said pair of supporting and moving arms (10′, 10″) and sliding thereupon, adapted to support said reel (B) in the pre-forming phase, and with which said first motor means (M1) are in a single piece.

5. Rewinder (1) according to claim 2, wherein said gripping means comprise a pair of jaws (9′, 9″) adapted to grip said spindles (2′, 2″) of said winding rod (A) once said transfer means have moved said reel (B) into said main cradle (C1) thereby allowing said first motor means (M1) to abandon the spindles (2′, 2″).

6. Rewinder (1) according to claim 5, wherein said gripping means comprise: guide means for said jaws (9′, 9″); third motor means (M3) of a screw/nut type adapted to impart a vertical translation movement to said jaws (9′, 9″), along said guide means.

7. Rewinder (1) according to claim 5, wherein said unloading means (7) of said formed reel (B) comprise: guide means for said gripping means (9′, 9″); fourth motor means (M4), adapted to impart a horizontal translation movement to said gripping means (9′, 9″) along said supporting frame (3) by means of said guide means.

8. Rewinder (1) according to claim 1, wherein it comprises an index (12) oscillating around an axis, provided at one end with a ply-forming roller (13) adapted to interact with said strip (N) to form a loop and facilitate its winding around said winding rod (A) when placed in said secondary cradle (C2).

9. Rewinder (1) according to claim 8, wherein it comprises a plurality of nozzles (14) adapted to spray air or water at a determined pressure against said strip (N) to push said loop between said winding rod (A) and said third roller (8).

10. Rewinder (1) according to claim 1, wherein said feed means (4) for said winding rod (A) comprise: a pair of jaws (19′, 19″) adapted to grip said spindles (2′, 2″) of said winding rod (A); a vertical downward conveyor (20) for said jaws (19′, 19″), adapted to cooperate with said transfer means in the proximity of said secondary pre-forming cradle (C2).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Further features and advantages of the invention will be more evident from the more detailed description set forth below, with the aid of the drawings, which show a preferred implementation thereof, illustrated by way of non-limiting example, wherein:

[0039] FIG. 1 shows, in a simplified side view represented in transparency for clarity, a paper mill rewinder for forming reels of paper strip material around a winding rod according to the invention;

[0040] FIGS. 2a, 3a, 4a, 5a, 6a show, in a simplified side view represented in transparency for clarity, the rewinder of FIG. 1 in five subsequent operating phases;

[0041] FIGS. 2b, 3b, 4b, 5b, 6b show, in a partial front view represented in transparency for clarity, a detail of the rewinder according to the invention in the five subsequent operating phases of FIGS. 2a, 3a, 4a, 5a, 6a, respectively.

Detailed description of a preferred embodiment of the invention

[0042] With reference to the details of the figures, there is illustrated a paper mill rewinder 1 for forming a reel B of paper strip material N around a winding rod A having a longitudinal axis x, the ends of which are provided with spindles 2′, 2″.

[0043] The strip N of material can be wound directly on this rod A, or on a cardboard core placed coaxial to this rod.

[0044] Said paper strip material can, by way of non-limiting example, be:

conventional tissue paper, normally used to manufacture toilet paper or napkins;
structured tissue paper, i.e., very thick single ply paper with structured and soft texture (very sensitive to problems of flattening and elongation and hence particularly suitable to be handled by unwinders according to the invention);
nonwoven or TAD (through air drying) paper.

[0045] Said rewinder 1 essentially comprises:

a supporting frame 3;
feed means 4 for a winding rod A;
a main forming cradle C1 for a reel B around said winding rod A, comprising a first 5 and a second 6 winding roller;
a secondary pre-forming cradle C2 for said reel B around said rod A, comprising a third winder roller 8 and lateral supporting means for said reel B;
means for transferring said reel B from said secondary pre-forming cradle C2 to said main forming cradle C1 without interruption to the winding of the strip N onto said rod,
means for unloading 7 said reel B once formed;
motor means for all the kinematic mechanisms of said rewinder 1;
a control unit.

[0046] Said first 5 and said second 6 winding roller that form said main forming cradle C1 are preferably coated with tungsten carbide to provide the strip N with a good grip during winding and hence always maintain a control on the tension of this strip.

[0047] Both said winding rollers 5, 6 are motorized and rotate in the same direction to determine winding of the strip N on the rod.

[0048] Said third winding roller 8 is also preferable coated with tungsten carbide and in turn rotates in the same direction as said winding rollers 5 and 6.

[0049] Said transfer means comprise a pair of supporting and moving arms 10′, 10″ of said reel B and a slide 11 placed between said pair of arms 10′, 10″ parallel to the main axis x of said winding rod A, and hence of said reel B, sliding upon said arms.

[0050] Said slide 11 is slidable along an inclined plane formed by said arms 10′, 10″ to keep the contact between said reel B in the pre-forming phase and said third winding roller 8.

[0051] In particular, said transfer means are adapted to:

receive a winding rod A from said feed means 4;
provide the lateral support for said secondary cradle C2 in order to support said reel B during the pre-forming phase by keeping it always in contact with said third winding roller 8;
support, through said slide 11, said reel B in the pre-forming phase, allowing it to slide as its diameter increases;
subsequently transfer said pre-formed reel B into said main cradle C1.

[0052] Specifically, said rewinder 1 comprises:

first motor means M1 stably associated with said slide 11, adapted to cooperate with said spindles 2′, 2″ and to impart a rotation movement to said winding rod A inside said secondary cradle C2;
second motor means M2 adapted to impart an oscillating movement to said pair of supporting and moving arms 10′, 10″, to transfer the pre-formed reel B from said secondary cradle C2 to said main cradle C1.

[0053] Said first motor means M1 comprise a pair of motorized conical punches 21′, 21″.

[0054] Said first motor means M1 are associated with said slide 11, so as to be able to move linearly therewith along said inclined plane, in order to always be in contact on the spindles 2′, 2″ at the ends of said winding rod A while the diameter of the reel B being pre-formed increases.

[0055] Said rewinder 1 also comprises gripping means adapted to cooperate idly with said spindles 2′, 2″ and to support said rod A above said main cradle C1.

[0056] Said gripping means comprise a pair of jaws 9′, 9″ adapted to grip said spindles 2′, 2″ of said winding rod A once said transfer means have moved said reel B into said main cradle C1 thereby allowing said first motor means M1 to abandon the spindles.

[0057] Said jaw gripping means 9′, 9″ have the function of supporting the reel B being formed to prevent out-of-roundness thereof, above all for very soft low density papers, but also the function of accompanying and unloading the formed reel B.

[0058] Said gripping means comprise:

guide means for said jaws 9′, 9″;
third motor means M3 of linear type adapted to impart a vertical translation movement to said jaws 9′, 9″, to lift said reel B along said guide means and then move it away from said main cradle C1.

[0059] Said guide and vertical translation means comprise a linear guide 15, sliding in which is a wheel 16 with which said jaws 9′, 9″ are associated.

[0060] Said third motor means M3 comprise a linear actuator 17 of a screw/nut type.

[0061] Said gripping means also cooperate with said unloading means 7 to allow said reel B formed by said main cradle C1 to be moved away.

[0062] In fact, said unloading means 7 of said formed reel comprise:

guide means of the track type 18, provided along said supporting frame 3, along which said gripping means 9′, 9″ slide;
fourth motor means (not illustrated) adapted to impart a horizontal translation movement to said gripping means.

[0063] Said feed means 4 of new winding rods A also comprise a pair of jaws 19′, 19″ adapted to grip the spindles 2′, 2″ of each new winding rod A to take it, with a vertical downward conveyor 20 of known type and cooperating with said transfer means, in the proximity of said secondary pre-forming cradle C2.

[0064] Said rewinder 1 comprises a motorized index 12 oscillating around an axis, adapted to interact with said strip N to form a loop and facilitate its winding around said winding rod A when placed in said secondary cradle C2.

[0065] In particular, said index 12 is provided at its free end with a ply-forming roller 13 adapted to cause a slack in the strip N around said winding rod A.

[0066] Advantageously, in the proximity of said third winding roller 8, there is provided a plurality of nozzles 14 adapted to spray air or water at a determined pressure against said strip N to push said slack of material between said winding rod A and said third roller 8.

[0067] In a variant, not illustrated, said nozzles 14 could also spray glue directly onto said winding rod A to promote the adhesion of the strip N and facilitate tearing thereof to separate the reel B already formed with the portion of strip that will subsequently start the new reel.

[0068] Said rewinder 1 comprises fifth M5, sixth M6 and seventh M7 motor means adapted to impart a rotation movement respectively to said first 5, second 6 and third winding roller 8.

[0069] The operation of the rewinder 1 is described below and with the aid of FIGS. 2-6, both in a side and in a front view.

[0070] FIGS. 2a and 2b show a phase of winding a first reel B1 around a rod Al inside said main forming cradle C1 as a result of the rotation of said first 5 and second 6 winding roller. In this phase, the strip N fed is wound around the rod A1 to form a reel B1. The winding rod A1 is supported by the gripping means, i.e., by the jaws 9′, 9″ that grip the spindles 2′, 2″ of the rod Al. Simultaneously, said feed means 4 pick up a new winding rod A2 from a magazine to make it available to said pair of supporting and moving arms 10′, 10″.

[0071] FIGS. 3a and 3b show the final phase of winding of the reel B1. After reaching the desired diameter, the rewinder 1 starts the reel change cycle: while the reel B1 formed is still in the main forming cradle C1, the pair of supporting and moving arms 10′, 10″ lower the new winding rod A2 taking it into the secondary pre-forming cradle C2, in contact with said third winding roller 8 and said slide 11. The first motor means M1 in a single piece with the slide 11 engage with the ends of the rod A2.

[0072] FIGS. 4a and 4b show the operation of tearing the strip N and of starting winding on the new rod A2: the control unit controls the upward oscillation of the index 12 so as to intercept the strip N and surround the rod A2. The nozzles 14 spray pressurized water on the portion of strip N in contact with the ply-forming roller 13 of the index 12, thereby causing the actual tearing of the strip N. The tail N′ of the strip completes its winding on the reel B1 already formed, while the head N″ of the strip is gripped between the new rod A2 and the third winding roller 8. In a preferred variant, said nozzles 14 could also spray a glue to promote adhesion of the head N″ of the strip on the rod A2. The first motor means M1 start to impart a rotation movement to said rod A2: winding of the strip N on said rod A2 and pre-forming of a new reel B2 inside said secondary cradle C2 commence. The formed reel B1, still supported by the gripping means 9′, 9″, is instead moved away horizontally along the tracks 18 of the supporting frame 3 freeing the main forming cradle C1.

[0073] FIGS. 5a and 5b show the phase of pre-forming the new reel B2 and preparing the main cradle C1, with repositioning of the gripping means 9′, 9″ above it.

[0074] FIGS. 6a and 6b show the phase of transferring the pre-formed reel B2 from the secondary cradle C2 to the main cradle C1. Said second motor means M2 impart the oscillation of the supporting and moving arms 10′, 10″ that accompany the rod A2 inside the jaws 9′, 9″ of the gripping means, which are in the open position above the main cradle C1. Once the rod A2 has been inserted into the jaws 9′, 9″, the first motor means M1 abandon the spindles 2′, 2″ of the rod A2 and the pair of arms 10′, 10″ can return to the initial position to pick up a new rod A3 carried by the feed means 4. The reel B2 instead continues to be formed in the main cradle C1.