EP2886319A1

EP2886319A1 - Device and method for the introduction of an inner bag in a rafia bag

Info

Publication number: EP2886319A1
Application number: EP13005967.8A
Authority: EP
Inventors: Bruno Duarte Costa Azevedo
Original assignee: Vitra Ind e Comercio de Maquinario Para Rafia Ltda
Current assignee: Vitra Ind e Comercio de Maquinario Para Rafia Ltda
Priority date: 2013-12-20
Filing date: 2013-12-20
Publication date: 2015-06-24

Abstract

The method for the introduction of an inner bag (3) in a bag of raffia (6), comprises the following stages:
a) Supply of the inner bag (3) on a passive table (4), and the raffia bag (6) on a suction table (7).
b) Application of air suction in some perforated pipes (11), aspiring and securing the inner bag (3), and approaching them under the action of a transverse actuator (51), folding the inner bag (3).

Applying suction to an elevator (71) and to the suction table (72), with an upward movement of the first , which causes the opening of the raffia bag (6) mouth.
c) Introduction into the raffia bag (6) of the folded inner bag (3), by the action of a longitudinal piston (52).
d) Unfolding of the inner bag (3) in the bag of raffia (6) by separating the perforated pipes (11).
e) Turn off the suction around the device, retiring the raffia bag (6) with the unfolded inner bag (3) inside by conventional means.

Description

The present invention relates to a device and method for automating the insertion of an inner bag in a raffia bag. Its field of application is the manufacture of packaging.

BACKGROUND OF THE INVENTION

Currently, the manufacturing of raffia bags with an inner bag as a liner is carried out manually. The raffia bag is made from a coil of tubular raffia fabric cut to the desired size for the bag depth. The inner bag, usually polyethylene, also comes in tubular form cut to the right dimensions, and its back bottom welded so that the product to be packaged in it is sealed from the outside. The process is done manually, the inner bag being placed on a hanger and the raffia bag coming from below. To access the inner bag during packaging operations, the inner bag is a little longer, so it does not interfere with the suction devices used during this operation. Manual entry of the inner bag in the raffia bag, and delicate and subsequent handling of the inner bag during the packaging make the operation very costly.
The problems mentioned above have been attempted to resolve, at least partially, by the device and method described in BR 10805186-0 A2 and BR 8802696-5 U2 A2 documents that consist basically in sizing the inner bag so that its mouth is level with the raffia bag, effecting a slant in the latter that allows access to the inner bag. In this way the packaging operation is easier, but problems of manual assembly manufacturing remain unresolved.
Accordingly, it is an objective of the present invention to achieve an economic manufacture of the raffia bag / liner bag assembly.
It is another objective of the present invention that the device used for manufacturing the bag assembly raffia / inner bag is simple and reliable.

DESCRIPTION OF THE INVENTION

To achieve the mentioned objectives a mechanized method has been devised to reduce the width of the inner bag and increase its rigidity to facilitate entry into the raffia bag.
The manipulation of the bag to the above procedure is possible thanks to the use of a mechanical device with two transverse axes movement, holding both bags by suction elements. In particular, the basic element of the device of the invention is constituted by two cars that embody a perforated tube for securing the inner bag by its sides. The contrary movement of the two cars causes the folding of the inner bag, and the perforated tubes themselves constitute sufficient stiffening element for the introduction of the inner bag in the raffia bag by a longitudinal movement of the cars. This introduction is facilitated by the simultaneous opening of the raffia bag mouth by the separation of an up moving suction elevator from a suction table, the raffia bag being immobilized between them.
The coordinated movement of both cars is achieved by a frame formed by two parallel bars joined together at their ends by two supports, each car being associated with a longitudinal piston and a transverse piston, which ensures their movement along two perpendicular axes.
Thus, the method comprises the following steps:

a) Supply of the inner bag on a passive table, and the raffia bag on a suction table , by conventional means.
b) Application of suction to the perforated tubes and suction table aspiring and securing the inner bag , and moving transversely in the direction of approach, under the action of transverse pistons, to fold the inner bag.
Applying suction in the elevator and in the suction table, with un upward movement of the first, which causes the opening of the raffia bag mouth.
c) Introduction of the folded inner bag in the raffia bag, by the action of the longitudinal pistons.
d) Unfolding the inner bag inside the raffia bag by a separation of the perforated tubes under the action of the transverse piston.
e) Turn off the suction from the whole device, retiring the raffia bag with the inner bag deployed by conventional means.

The advantages of the process are:

Introduction of the inner bag into the sack raffia very sure.
Folding and stiffening of the inner bag in a two step single operation.

The advantages of the device are:

Great economy, by removing all manual operations.
Excellent repeatability and accuracy in the positioning of the inner bag in the raffia bag.
Economical and reliable mechanism, especially if used pneumatic actuator.
Easy to incorporate into existing production facilities, being included between cutting and packaging operations.

Brief Description of the Drawings

To complement the above description, and in order to aid a better understanding of the characteristics of the invention, we will proceed with a detailed description of a preferred embodiment, based on a set of drawings that accompany this specification as a guideline and not a limitation.

Figure 1 shows a perspective view of the device of the invention.
Figure 2 shows a detail, in section, of the folding operation of the inner bag
Figure 3 shows a plan view of the device of the invention during step a), feeding a new inner bag and a new raffia bag.
Figure 4 shows a plan view of the device of the invention during step b), folding of the inner bag and opening the raffia bag mouth.
Figure 5 shows a plan view of the device of the invention during step c), for introducing the folded inner bag into the raffia bag.
Figure 6 shows a plan view of the device of the invention during the step d), of unfolding the inner bag inside the raffia bag.
Figure 7 shows a side view corresponding to the step b) of Figure 4.
Figure 8 shows a side view corresponding to step c) of Figure 5.

In the above figures, reference numerals correspond to the following parts and elements:

1 Car
2 Rack
3 Inner bag
4 Passive table
6 Raffia bag
7 Suction table
9 Guide plate
11 Perforated tube
12 Guide tube
21 Bars of the rack
22 Supports of the rack
51 Transverse actuator
52 Longitudinal actuator
71 Elevator
72 Elevator Hose
91 Slots

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

As shown in Figure 1, the device of the invention comprises two cars (1), each of which is attached to a perforated tube (11), and a guide tube (12) passing through a slot (91) arranged in a guide plate (9).
A rack (2) allows the coordinated movement of the two cars (1), being constituted by two rods (21) passing through respective holes provided in the cars (1). Two supports (22) hold together the parallel bars (21) of the rack (2).
Under the perforated tubes (11), a passive table (4) and a suction table (7), fixed to the ground and between them are disposed. An elevator (71) attached to a suction hose (72) and provided with a vertical movement is disposed over the suction table (71) . Finally, a set of transverse actuators (51) attached to the guide tubes (12) of the cars (1) and integral with the guide (9) plate, and a set of longitudinal piston (5) attached to the passive table (4) and integral of the cars (1) ensure the movement of the cars (1) in two perpendicular axes.
The process of the invention using the device just described comprises the following steps.

a) Feeding the inner bag (3) on the passive table (4) and raffia bag (6) on the suction table (7). Fig.3
b) Applying suction to the perforated tubes (11) from above, holding the inner bag (8), and move the cars (1) transversely in the direction of joining them under the action of the transverse actuator (51), fold the inner bag (3).

Application of suction in the elevator (71) and the suction table (7) with the first moving upward, causing the opening of the sack raffia 6).
Figures 2,4 and 7.

c) Introduction into the sack raffia (6) of the inner bag (3), folded , by action of the longitudinal actuator (52). Figures 5 and 8
d) Unfolding of the inner bag (3) inside the bag of raffia (6) by the separation of the perforated tubes (11) under the action of transverse actuators (51). Figure 6

Subsequently, the suction is turned off around the device and the raffia bag (6) with the inner bag (3) unfolded is removed by conventional means. Will be apparent to the skilled man a number of variants and alternatives which, respecting the essential nature of the invention, to adapt the design to the means of production available. Thus, there is disclosed a guide (9) with sliding plate (91) to define the movement of the carriages (1) for the folding of the inner bag (3) but it is evident that a device could be used in a circular motion crank or any equivalent mechanism. Likewise it has proved advantageous to use pneumatic cylinders as a suction device, but could hydraulic rams, electrical actuators or any equivalent device could be used. Some constructive aspects of the device that would complicate the drawings and are not essential to the invention have been omitted. Thus it is obvious that the ends of the longitudinal rods of the longitudinal actuators (52) which are attached to the passive table (4) should incorporate a sliding coupling enabling the transverse relative movement. As before this could be solved by equivalent mechanisms such as articulated joints.

Claims

Device for the introduction of an inner bag (3) in a raffia bag (6), characterized by comprising the following elements;
two cars (1) each of which is attached to a perforated tube (11) and a guide tube (12),
a guide plate (9), provided with two slots (91) through which pass the guide tubes (12),
a rack (2), formed by two parallel bars (21) passing through respective holes provided in the cars (1), being joined at their ends by means of respective supports (22),
a passive table (4) and a suction table (7), integral of each other and the ground, arranged below the perforated tubes (11),
an elevator (71) attached to a suction hose (72), disposed over the suction table (7), and capable of a lifting movement,
two transverse actuators (51), attached to the guide tubes (12) by their stems and integral of the guide plate (9), and two longitudinal actuators (52) tubes attached by their stems to the passive table (4) and integral of the cars (1).
Method for the introduction of an inner bag in a bag of raffia , using the device of claim 1, characterized by comprising the following stages:
a) Supply of the inner bag (3) on the passive table (4), and the raffia bag (6) on the suction table (7), by conventional means.

b) Application of suction in the perforated pipes (11), aspiring and securing the inner bag (3), and moving transversely in the direction of approach, under the action of the transverse piston (51), folding the inner bag (3).
Applying suction to the elevator (71) and to the suction table (72), with an upward movement of the first, which causes the opening of the raffia bag (6) mouth.
c) Introduction into the raffia bag (6) of the folded inner bag (3), by the action of the longitudinal piston (52).

d) Unfolding of the inner bag (3) in the bag of raffia (6) by separating the perforated pipes (11) under the action of the transverse actuators (51).

e) Turn off the suction around the device, retiring the raffia bag (6) with the unfolded inner bag (3) by conventional means.