EP1764331A1

EP1764331A1 - Automatic device for producing cut, folded and piled products

Info

Publication number: EP1764331A1
Application number: EP06118599A
Authority: EP
Inventors: Giovanni Marsiletti
Original assignee: Wipcor Srl
Current assignee: Wipcor Srl
Priority date: 2005-09-15
Filing date: 2006-08-08
Publication date: 2007-03-21
Also published as: ITTO20050631A1

Abstract

Assembly for manufacturing products starting from at least one continuous trip (14) of flexible material advancing in longitudinal direction. The assembly comprises:
a cutting unit (18) comprising a cutting cylinder (24) and an abutting cylinder (26) rotatable around respective axes, mutually parallel and co-operating with each other to cut the continuous strip (14) in transverse direction and form successive strip segments (14a) whose length is twice the length of a product;
a bending and transfer cylinder (20), rotatable around an axis that is parallel to the axes of rotation of the cutting cylinder (24) and of the abutting cylinder (26) and comprising a plurality of actuated pincers (34), able to grip a central area of a cut strip segment (14a), in which the bending and transfer cylinder (20) draws, by means of said pincers (34), successive strip segments at the abutting cylinder (36) and transfers the successive strip segments (14a) towards a release area (36) and in which during said transfer operation the successive strip segments (14a) are bent in half around a transverse bending line, and
a station for forming product packs (54) situated at said release area (36), in which successive bent strip segments (14a) each forming a product are detached from the bending and transfer cylinder (20) and piled on a movable pan (56) which moves progressively away from the bending and transfer cylinder (20) as the thickness of the pile of products increases.

Description

The present invention relates to a device for transverse bending, transverse cutting both by pressure and in scissors mode, and vertically piling and transporting the piles in automatic mode of products obtained with materials suitable for this work process, such as: non-woven fabric, spunlace, tissue, paper in general, plastic materials, drylaid etc., both dry and soaked.
The invention relates to an assembly that, starting from a continuous strip of flexible material advancing in longitudinal direction, manufactures the product by transversely cutting the continuous strip and bending the cut segments of strip.
One of the main drawbacks of prior art assemblies for the manufacture of such products is the limited working rate.
In existing assemblies, above a certain production rate the assemblies that transfer the product from the cutting area to the area where the product packs are formed starts having critical problems.
In most known assemblies for the manufacture of humidified products, the products are transported from the cutting area to the area where the product packs are formed by means of belt conveyor devices.
In these known solutions, the product tends to slip on the conveyor belts above a certain speed.
For this reason, known assemblies have a production rate that generally does not exceed 50 packs per minute.
The object of the present invention is to provide an improved assembly for the manufacture of a product, which can operate safely and reliably at higher production rates than prior art assemblies.
According to the present invention, said object is achieved by an assembly for manufacturing products, having the characteristics set out in the claims.
The characteristics and the advantages of the assembly according to the present invention shall become readily apparent in the detailed description that follows, provided purely by way of non limiting example, with reference to the accompanying drawings, in which:

Figure 1 is a schematic perspective view of an assembly according to the present invention;
Figure 2 is a schematic front elevation view according to the arrow II of Figure 1;
Figures 4 through 8 are schematic front views showing the sequence of operation of the assembly according to the invention.

With reference to Figure 1, the number 10 designates an assembly for manufacturing products according to the present invention.
The assembly 10 comprises a stationary structure including two vertical walls 12, parallel to each other, which support the rotatable parts of the machine.
The assembly 10, represented in Figure 1, is configured to operate simultaneously on four continuous strips 14, positioned parallel to each other.
However, the present invention is not limited to the number of parallel strips fed simultaneously to the assembly.
The assembly 10, according to the invention, may be configured to operate with a single strip or with any number of strips equal to or higher than two.
The strips 14 constitute the starting material for the manufacture of these products.
Said strips are collected in continuous form in rolls or coils (not shown), wherefrom unwind the segments of strip that are fed to the assembly 10 to form the product.
The strips 14 can be constituted by non-woven fabric, tissue paper or any other material suitable for this kind of production (handkerchiefs, table napkins, etc.).
If the assembly 10 is configured for the manufacture of humidified products, the belts 14 reach the inlet section of the group 10 already soaked with the liquid substance.
In its essential elements, the assembly 10 comprises an inlet section formed by the cylinders 22, a cutting unit 18, a bending and transfer cylinder 20 and a station for forming product packs, designated by the reference 54 in Figure 2.
In the remainder of the description, reference shall be made to the structure of the assembly that operates on a single strip 14.
It is readily apparent that to operate simultaneously on multiple strips 14, the assembly will be provided with multiple, mutually identical longitudinal sections each of which is dedicated to processing a respective strip 14.
With reference to Figure 4, the inlet section comprises two feeding rollers 22 whose purpose is to feed the strip 14 in the longitudinal direction at a constant rate.
The assembly 10 is preferably positioned in such a way as to advance the strip 14 in a vertical plane from above downwards.
Downstream of the feeding cylinders 22, the strip 14 enters the cutting unit 18 which comprises a cutting cylinder 24 and an abutting cylinder 26.
These two cylinders are rotatable around respective mutually parallel horizontal axes, and they rotate in opposite directions.
The cutting cylinder 24 bears a plurality of cutting blades 28 equally distanced from each other along the perimeter of the cylinder 24.
In the illustrated example, there are three cutting blades 28.
The abutting cylinder 26 bears a plurality of abutting blocks 30 equally distanced along the perimeter of the cylinder 26.
The number and the angular distance of the abutting blocks 30 is equal to the number and to the angular distance of the cutting blades 28.
The cylinders 24, 26 rotate in phase with each other so that each cutting blade 28 at each revolution comes in contact with a respective abutting block 30 in order to execute a cut in the transverse direction of the strip 14 that passes the cylinders 24, 26.
The cutting cylinder 24 and the abutting cylinder 26 rotate at constant speed and periodically execute the transverse cut of strip segments 14a, each of which has a length that is equal to the distance, in the peripheral direction, between two adjacent cutting blades 28.
The cut strip segments 14a have a length equal to the length of the product to be obtained.
After the cut, the segments 14a remain adherent to the surface of the abutting cylinder 26.
The abutting cylinder 26 is preferably provided with a plurality of inserting members 32 each of which has the shape of a blade or of a comb with an end that projects slightly beyond the outer surface of the cylinder 26.
The inserting members 32 are positioned intermediately between the abutting blocks 30.
Still with reference to Figure 4, underneath the cutting unit 18 is positioned the bending and transfer cylinder 20.
The cylinder 20 rotates around a horizontal axis parallel to the axes of rotation of the cylinders 24, 26.
The outer surface of the cylinder 20 is substantially tangential to the abutting cylinder 26. The bending and transfer cylinder 20 comprises a plurality of pincers 34 equally distanced from each other along the perimeter of the cylinder.
The pincers 34 are closed when they pass at the area of tangency with the abutting cylinder 26 and they are open when they pass through a release area designated by the reference number 36. The pincers 34 remain closed in the path between the cutting unit 18 and the release area 36 and they instead remain open in the path that goes from the release area 36 to the cutting unit 18.
Each pincer 34 is mounted on the shaft 38, which extends parallel to the axis of rotation of the cylinder 20 and is housed in a respective slot 39 obtained in the body of the cylinder 20.
With reference to Figure 3, the shaft 39 of each pincer 34 is rotatable around its own axis relative to the cylinder 20 and it is fastened at each of its ends to an actuating lever 40 that actuates the oscillation of the shaft 38 around its own longitudinal axis.
The lever 40 co-operates with an elastic element which tends to maintain the pincer 34 towards a closed position.
The actuating lever 40 also bears an idle wheel 45 that co-operates with a stationary cam 46 that is fixed relative to a respective vertical wall 12. The cam 46 determines the open or closed condition of each pincer 34.
With reference to Figure 3, the in-phase rotation of the cylinder 20 and of the abutting cylinder 26, causes each inserting member 32 to be at the open space of a respective pincer 34; hence, the central part of the cut strip segment 14a is thrust into the open space between the pincers 34 and an edge 48 of the slot 39. Continuing the rotation of the cylinder 20, the pincer 34, situated in the position of tangency with the abutting cylinder 26, closes bringing the pincer 34 in contact with the edge 48.
As Figure 3 shows, when the pincers 34 close they grab a central segment of the strip 14a squeezing it between the pincers 34 and the edge 48 of the slot 39.
The inserting member 32 can be oscillating around a longitudinal axis or it can be associated to an elastic device that allows a disengagement of the inserting member 32 when the latter, during the rotation of the cylinders 20 and 26, comes in contact with the edge 48 of the respective pincers 34.
With reference to Figure 4, after the grip of a cut strip segment 14a by pincers 34, the additional rotation of the cylinder 20 causes the segment 14a to be bent in half around a transverse bending line defined by the grip area of the pincers 34. Continuing the rotation, the bent strip segment 14a meets a stationary deflector member 52 that allows to complete the bending of the cut strip segment 14a.
As shown in Figure 4, the stationary deflector member 52 presses each cut and bent strip segment 14a against the outer surface of the cylinder 20 and executes a product formed by two bent and superposed edges.
The bending operation completes the product formation step.
The product obtained by cutting and bending the strip segments 14a is detached from the bending and transfer cylinder 20 and piled to form a pack comprising a pre-determined number of pieces.
These operations are performed in a pack forming station positioned at the detachment area 36 and globally designated by the reference number 54.
With reference to Figure 2, the pack forming station 54 comprises a pan 56 movable in the vertical direction, whereon are piled the products that are detached from the bending and transfer cylinder 20 in the way that will be described hereafter.
The pan 56 moves progressively away from the cylinder 20 in the way that will be described hereafter.
The pan 56 moves progressively away from the cylinder 20 as the number of products piled thereon increases.
A control unit commands the progressive lowering of the pan 56, as a function of the rotation of the bending and transfer cylinder 20.
When the product pack reaches the desired height, the pack is moved away from the pan and is sent to a packaging station (not shown).
With reference again to Figure 2, the pack forming station 54 comprises a detaching device 58 whose purpose is to detach the product 14a from the surface of the cylinder 20 and to pile it on the pan 56.
The detaching device 58 comprises an oscillating element 60, provided with arms 62 capable of entering respective grooves 64 formed in the cylinder 20.
The oscillating element 60 oscillates around an axis 66 and carries out an oscillation cycle in which the arms 62 start from a position in which they are inserted in the grooves 64.
In each of said oscillation cycles the oscillating element 60 detaches a piece of product 14a from the cylinder 20 and deposits it on the pan 56 or at the top of the pile formed by pieces previously deposited on the pan 56.
The oscillating element 60 is fastened to an actuating lever A, which is actuated by means of a connecting rod and crank mechanism.
The actuating mechanism also comprises a pneumatic actuator 74.
The actuator 74 has the purpose of temporarily changing the oscillation cycle of the oscillating element 60 on the occasion of the completion of a pack of products in order not to hamper the grip of the completed pack by a conveying member.
The operating sequence of the assembly according to the present invention is described hereafter with reference to Figures 4 through 8.
In Figure 4, the pan 56 is empty and is positioned closest to the cylinder 20.
The arms 62 of the oscillating element 60 are inside the grooves 64 of the cylinder 20.
A pincer 34 is approaching the release area 36.
In this phase, one of the cams 46 that co-operate with the actuating levers 40 of the pincer 34 actuates the opening of the pincer 34 that reaches the position 36.
After the opening of the pincer 34, the oscillating element 60 oscillates downwards, detaching the product from the surface of the cylinder 20. The product is deposited on the upper surface of the pan 56.
As the deposition on the pan 56 proceeds, the pan lowers to leave space for the formation of the pack.
Figures 4 and 7 respectively show the two extreme positions of the oscillation travel of the oscillating element 60.
In the position of Figure 5, the oscillating element 60 sets a just-detached product onto the pile of products already deposited on the pan 56.
Figure 7 shows the step in which the formation of a pack P was completed.
In this condition, the pan 56 is substantially flush with a stationary transport plane 76.
Underneath the plane 76 is provided a chain 78 bearing a plurality of driving members 80 (Figure 8), which grip and convey the packs.
In the step shown in Figure 7, after the detachment of the last product of the pack, the actuator 74 is activated and it raises the oscillating member 60 in advance with respect to the normal operating cycle to enable the evacuation of the pack P by a conveying member 80.
Lastly, as shown in Figure 8, the pan 56 rises and the cycle recommences with the detachment of the first product of the new pack.
The solution, according to the present invention, enables considerably to increase the working rate with respect to prior art solutions.
In the solution according to the present invention, the individual cut strip segments are gripped and held by the pincers of the bending and transfer cylinder until reaching the release area.
This avoids all risk of the product slipping during high speed operation.
The product is bent precisely and safely because the bending area is defined by the gripping area of the pincers.
The piling operation for the formation of the packs takes place safely and effectively because each product is detached from the cylinder 20 and set down on the pan or on the top of the pack during the formation by the oscillating element 60.
Naturally, the construction details and the embodiments may be widely varied from what is described and illustrated herein, without thereby departing from the scope of the invention, as defined in the appended claims.

Claims

Assembly for producing bent products starting from at least one continuous strip (14) of flexible material advancing in longitudinal direction, in which each product is formed by a bent strip segment (14a), characterised in that it comprises:
a cutting unit (18) comprising a cutting cylinder (24) and an abutting cylinder (26) rotatable around respective axes, mutually parallel and co-operating with each other to cut the continuous strip (14) in transverse direction and form successive strip segments (14a) whose length is twice the length of a product;

a bending and transfer cylinder (20), rotatable around an axis that is parallel to the axes of rotation of the cutting cylinder (24) and of the abutting cylinder (26) and comprising a plurality of actuated pincers (34), distanced from each other along the perimeter of the bending and transfer cylinder (20) and able to assume an open position and a closed position; each of said pincers (34) being able to grip a central area of a cut strip segment (14a), in which the bending and transfer cylinder (20) draws, by means of said pincers (34), successive strip segments at the abutting cylinder (36) and transfers the successive strip segments (14a) towards a release area (36) and in which during said transfer operation the successive strip segments (14a) are bent in half around a transverse bending line, and

a station for forming product packs (54) situated at said release area (36), in which successive bent strip segments (14a) each forming a product are detached from the bending and transfer cylinder (20) and piled on a movable pan (56) which moves progressively away from the bending and transfer cylinder (20) as the thickness of the product pile increases.
Assembly as claimed in claim 1, characterised in that the abutting cylinder (26) is provided with a plurality of inserting elements (32) able to insert the central part of each strip segment (14a) into the open part of a corresponding pincer (34).
Assembly as claimed in claim 1, characterised in that each of the pincers comprises a shaft (38) oscillating around an axis that is parallel to the axis of rotation of the bending and transfer cylinder (20), said shaft (38), bearing a flexible metallic lamina (34) able to grip a cut strip segment (14a).
Assembly as claimed in claim 3, characterised in that each pincer (34) is associated to an actuating lever (40), fastened to an end of said shaft (38) and co-operating with a stationary cam (46).
Assembly as claimed in claim 1, characterised in that it comprises a detaching device (58) provided in said pack forming station (54), the detaching device (58) comprising an oscillating element (60) including a plurality of arms (62) able to be cyclically inserted into and extracted from circumferential grooves (64) of the bending and transfer cylinder (20).
Assembly as claimed in claim 1, characterised in that it comprises a stationary deflector member (52) for bending said strip segments (14a) held by the pincers (34), situated upstream of said releasing station (36).