Web folding device for a container forming and filling machine

Abstract

 The fording device comprises a triangular folding plate (1) supported on a frame (19) by a plate support (2). The plate has a horizontal rear edge (1a) and two side edges (1b) converging in a front vertex (1c) located at a level lower than the rear edge. A continuous web of film (F) is guided below the triangular folding plate (1) by a horizontal guide roller (3) and is folded by a pair of vertical guide rollers (4) cooperating with the side edges (1b). The triangular folding plate (1) has retention walls (6) arranged along the side edges (1b) and joined to one another at the front vertex (1c) which together with the plate form a tray to collect any leak from a transverse adjustment mechanism (5) located on the plate to prevent contaminating the containers.

Description

Field of the Invention

[0001] The present invention relates to a web folding device for a container forming and filling machine, the containers being such as those made of sheet plastic material intended for containing food products.

Background of the Invention

[0002] Web folding devices for container forming and filling machines are known, such devices comprising a triangular folding plate below which a continuous web of film coming from a web supplying apparatus passes, where the triangular folding plate comprises a rear edge and two side edges converging in a front vertex, and where the moving web of film, which is required by a container forming mechanism, enters at said rear edge or wider part of the triangular folding plate, passes tightly fit over the mentioned converging side edges of the triangular folding plate, where the web is folded, and then is constrained by vertical cylinders such that the web of film is gradually longitudinally folded in half. Next, the two overlapping halves of the web of film will be attached to one another by separate transverse heat welding lines, filled with a food product, sealed by heat welding, even vacuum-sealed if needed, and suitably cut into suitable lengths in other sections of the container forming and filling machine.

[0003] It is also known that the folding device further comprises transverse position adjustment means for adjusting the transverse position of the web of film with respect to the triangular folding plate so that the web is folded exactly along its longitudinal midline. These transverse position adjustment means are usually located above an upper surface of the triangular folding plate.

[0004] One drawback of the folding devices of the state of the art is that any oil, grease or similar lubricant that leaks or seeps out from the mentioned transverse position adjustment means will fall onto the triangular folding plate, and due to the fact that the plate is forwardly and downwardly inclined, there is a risk of lubricant leaks sliding over the triangular folding plate to the vertex thereof and being deposited precisely in the midline of the continuous web of film which will finally form the bottom of the recipients that will contain the food product to be packaged, which can cause product contamination.

Disclosure of the Invention

[0005] The present invention contributes to mitigating the foregoing and other drawbacks by providing a web folding device for a container forming and filling machine comprising a triangular folding plate having an upper surface, a lower surface, a rear edge and two side edges converging in a front vertex. The triangular folding plate is supported by a plate support such that said rear edge is in a horizontal position and said front vertex is located at a level lower than the rear edge. Said plate support is connected to the mentioned upper surface of the triangular folding plate.

[0006] The folding device further comprises a horizontal guide roller arranged parallel to the rear edge of the triangular folding plate to guide a moving continuous web of film such that the web is in contact with said lower surface of the triangular folding plate, and one or more pairs of vertical guide rollers arranged for folding said continuous web in half in cooperation with said side edges of the triangular folding plate.

[0007] A transverse adjustment mechanism is arranged for adjusting a transverse position of said plate support with respect to a frame, for the purpose of locating said front vertex of the triangular folding plate in the center of the continuous web of film.

[0008] One feature of the folding device of the present invention is that the triangular folding plate has retention walls projecting upwards from the upper surface thereof. These retention walls extend along the side edges of the triangular folding plate and join to each other at the front vertex, where the upper surface of the triangular folding plate and said retention walls form a tray arranged to collect any lubricant or other product leak from the mentioned transverse adjustment mechanism.

[0009] The lower surface of the triangular folding plate and an outer surface of the retention walls preferably have a non-stick coating.

[0010] In one embodiment, the transverse adjustment mechanism comprises a carriage to which the plate support is fixed, transverse guides which are fixed to a structural member of said frame and to which said carriage is coupled, and a first actuator, such as a first electric motor for example, operatively connected for moving the carriage along the transverse guides. The plate support has a base which sits on the upper surface of the triangular folding plate, and legs connecting said base to the carriage.

[0011] For example, threaded rods which are inserted into corresponding holes of the base of the plate support project from the upper surface of the triangular folding plate, and nuts coupled to said threaded rods fasten the triangular folding plate to the base of the plate support. Said nuts coupled to the threaded rods are preferably attached to respective manually operated knobs which allow fixing or releasing the triangular folding plate without needing to use tools.

[0012] Optionally, the folding device of the present invention further comprises a vertical adjustment mechanism for adjusting a vertical position of said plate support with respect to the frame. Said vertical adjustment mechanism comprises slides to which the mentioned structural member is fixed, vertical guides which are fixed to the frame and to which said slides are coupled, and a second actuator, such as a second electric motor for example, operatively connected for moving the slides along the vertical guides.

Brief Description of the Drawings

[0013] The foregoing and other features and advantages will become more evident from the following detailed description of an embodiment with reference to the attached drawings, in which:

Figure 1 is a perspective view of a web folding device according to an embodiment of the present invention, where a continuous web of film has been depicted with dotted lines; and

Figure 2 is a perspective view of the folding device of Figure 1 with the triangular folding plate separated from the plate support, and where the pair of vertical guide rollers have been omitted.

Detailed Description of an Exemplary Embodiment

[0014] As shown in Figures 1 and 2, according to an embodiment of the present invention the folding device comprises a triangular folding plate 1 having a horizontal rear edge 1a and two side edges 1b converging in a front vertex 1c located significantly lower than the rear edge 1a. The two side edges 1b are of the same length, such that the plate has the shape of an isosceles triangle. The triangular folding plate 1 is supported on a frame 19 by a plate support 2.

[0015] The folding device also comprises a horizontal inlet guide roller 3 adjacent to the rear edge 1a of the triangular folding plate 1 to guide a continuous web of film F (Figure 1) coming from a supplying device (the description of which has been omitted as it is unrelated to the invention) towards said triangular folding plate 1, a pair of vertical guide rollers 4 arranged adjacent to the front vertex 1c of the triangular folding plate for folding said web F in half at the outlet of the triangular folding plate 1, and a transverse adjustment mechanism 5 for adjusting the transverse position of the plate support 2 with respect to said frame 19 and accordingly with respect to the continuous web of film F.

[0016] During operation, the continuous web of film F enters guided by the horizontal guide roller 3 through the rear edge 1a of the triangular folding plate 1, contacts a lower surface of said triangular folding plate I and is folded along the length of same around the two side edges 1b of the plate which are forwardly and downwardly inclined, and is constrained by the vertical guide rollers 4 such that the continuous web of film F is longitudinally folded in half by the front vertex 1c of the triangular folding plate.

[0017] From the vertical guide rollers 4, the folded continuous web of film F with its two overlapping halves continues its course towards other points and stations of the container forming and filling machine where the folding device of the present invention is installed.

[0018] The triangular folding plate 1 has retention walls 6 extending upwards along the side edges 1b and converging in the front vertex 1c. These retention walls 6 can, for example, be formed by respective upward folds of extensions of the side edges 1b. The retention walls 6, which will usually be of little height, form together with the upper surface of the triangular folding plate 1 a tray suitable for collecting any oil, grease or similar lubricant that may leak from the transverse adjustment mechanism 5 and/or from other nearby mechanical members, and thus preventing these lubricant leaks from being able to contaminate the containers formed with the continuous web of film F and/or the product contained therein.

[0019] To facilitate the passage of the continuous web F in contact with the triangular folding plate 1, the lower surface thereof as well as an outer surface of the mentioned retention walls 6 have non-stick properties provided, for example, by a non-stick coating and/or engraving.

[0020] The mentioned frame 19 comprises a bridge-like structural member 9 arranged over the triangular folding plate 1. The mentioned structural member 9 has fixed thereto transverse guides 8 in which a carriage 7 is coupled such that said carriage 7 can run along the transverse guides 8 under the action of a first actuator 10, such as a first electric motor for example. The carriage 7 has fixed thereto the plate support 2 supporting the triangular folding plate 1. Thus, the transverse positioning of the triangular folding plate 1 is provided by activating the first actuator 10, such that the front vertex 1c thereof is located in the center of the continuous web of film F.

[0021] The folding device further comprises a vertical adjustment mechanism 11 for adjusting the vertical position of the plate support 2 with respect to the frame 19. This vertical adjustment mechanism 11 comprises slides 12 fixed to the structural member 9 and coupled to vertical guides 13 fixed to the frame 19. The slides 12 include respective nuts coupled to vertical spindles 18, and a second actuator 17, such as a second electric motor, is operatively connected by means of a transmission shaft 20 and corresponding transfer elements 21 for rotating said vertical spindles 18 and thereby moving said slides 12 and the structural member 9 up and down the vertical guides 13, whichever is appropriate.

[0022] The plate support 2 comprises legs 2b holding a base 2a and a series of threaded studs 14 which can be inserted into corresponding holes 15 formed in the base 2a of the plate support 2 project from the upper surface of the mentioned triangular folding plate 1 (Figure 2). Nuts provided with a knob 16 can be coupled to an end of said threaded studs 14 projecting from the base 2a, whereby the triangular folding plate 1 configured as a collecting tray can be disassembled separating it from the base 2a of the plate support 2, as illustrated in Figure 2, for example to facilitate cleaning.

[0023] Therefore, the folding device of the present invention assures that the continuous web of film F is folded by the triangular folding plate 1 without the risk of contamination, and allows the position of the triangular folding plate 1 to be adjusted both in the transverse direction, to assure that the continuous web of film F is correctly folded in the center thereof, and in the vertical direction, to assure a correct interaction of the continuous web of film F with the horizontal guide roller 3 and the pair of vertical guide rollers 4.

[0024] The scope of the present invention is defined in the attached claims.

Claims

1. A web folding device for a container forming and filling machine, said folding device comprising:

- a triangular folding plate (1) having an upper surface, a lower surface, a rear edge (1a) and two side edges (1b) converging in a front vertex (1c);

- a plate support (2) connected to said upper surface of the triangular folding plate (1) to support the triangular folding plate (1) with said rear edge (1a) in a horizontal position and said front vertex (1c) located at a level lower than the rear edge (1a);

- a horizontal guide roller (3) parallel to the rear edge (1a) and arranged to guide a moving continuous web of film (F) in contact with said lower surface of the triangular folding plate (1);

- at least one pair of vertical guide rollers (4) for folding said continuous web of film (F) in half in cooperation with said side edges (1b) of the triangular folding plate (1), and

- a transverse adjustment mechanism (5) for adjusting a transverse position of said plate support (2) with respect to a frame (19) for the purpose of locating said front vertex (1c) of the triangular folding plate (1) at the center of the continuous web of film (F),

characterized in that the triangular folding plate (1) has retention walls (6) projecting upwards from the upper surface thereof and which extend along the side edges (1b) and join to one another at the front vertex (1c), where the upper surface of the triangular folding plate (1) and said retention walls (6) form a tray arranged to collect any leak from said transverse adjustment mechanism (5).

2. The folding device according to claim 1, characterized in that the lower surface of the triangular folding plate (1) and an outer surface of the retention walls (6) have a non-stick coating and/or engraving providing non-stick properties.

3. The folding device according to claim 1, characterized in that the transverse adjustment mechanism (5) comprises a carriage (7) to which the plate support (2) is fixed, transverse guides (8) which are fixed to a structural member (9) of said frame (19) and to which said carriage (7) is coupled, and a first actuator (10) operatively connected for moving the carriage (7) along the transverse guides (8).

4. The folding device according to claim 3, characterized in that the plate support (2) has a base (2a) which sits on the upper surface of the triangular folding plate (1), and legs (2b) connecting said base (2a) to the carriage (7).

5. The folding device according to claim 4, characterized in that threaded rods (14) which are inserted into corresponding holes (15) of the base (2a) of the plate support (2) project from the upper surface of the triangular folding plate (1), and nuts coupled to said threaded rods (14) fasten the triangular folding plate (1) to the base (2a) of the plate support (2).

6. The folding device according to claim 5, characterized in that said nuts coupled to the threaded rods (14) are attached to respective manually operable knobs (16).

7. The folding device according to any one of the preceding claims, characterized in that it further comprises a vertical adjustment mechanism (11) for adjusting a vertical position of said plate support (2) with respect to the frame (19).

8. The folding device according to claim 7, characterized in that said vertical adjustment mechanism (11) comprises slides (12) to which said structural member (9) is fixed, vertical guides (13) which are fixed to the frame (19) and to which said slides (12) are coupled, and a second actuator (17) operatively connected for moving the slides (12) along the vertical guides (13).

Drawing