Bag filling cone for a filling station of packaging machines, filling station and filling method using said cone

Abstract

A filling cone (10) for a filling station (100) for filling bags (1), comprises: two half-shells (11,12) arranged opposite each other in a longitudinal direction (X-X) parallel to the widthwise dimension of a bag to be filled, the two half- shells being coupled together so as to define walls (12a, 12b,11 a,11b) of the cone and a bottom dispensing mouth (10a) of the cone, and being movable between a relative minimum opening position of the bottom mouth (10a) of the cone and a maximum opening position of the cone mouth, the half-shells each having a lateral side wall (11a, 12a) of the cone, situated opposite each other in the longitudinal direction (X-X). A pair of wedge elements (14), each arranged on the outside of a respective lateral side wall of the cone, is displaceable with respect to the said side wall between a top raised position and a bottom lowered position, projecting from the cone mouth.

Description

[0001] BAG FILLING CONE FOR A FILLING STATION OF PACKAGING MACHINES, FILLING STATION AND FILLING METHOD USING SAID CONE

[0002] DESCRIPTION

[0003] The present invention relates to a bag filling cone for a filling station of packaging machines, as well as to a filling station and a filling method which use the filling cone.

[0004] It is known in the commodities sector relating to the packaging of bulk material that there exists the need to arrange said material inside bags which must be filled with a predetermined amount of material and then sealed.

[0005] It is also known that, for this purpose, automatic bag filling machines have been developed, an example of said machines consisting of so-called forming and filling machines which are able to perform at high speed the cycle of forming the bag or picking up a preformed bag, filling the bag and performing final sealing of the bag mouth.

[0006] It is also known that the bag filling step is performed by means of a filling cone arranged with its vertex directed towards the mouth of the underlying bag and top end directed towards an overlying hopper for supplying the product to be packaged.

[0007] The filling cone comprises two half-shells which are designed to be moved from a position for substantially closing a bottom dispensing mouth of the cone, for retaining the product, into a position for opening the dispensing mouth and releasing the product.

[0008] The step of filling a bag by means of said filling cones, which is the longest of the various steps of the entire machine cycle, is subject, among other things, to two main problems consisting of the need to ensure:

[0009] - rapid and precise insertion of the cone mouth inside the bag mouth which is only partially open;

[0010] - as rapid as possible discharging of the product in order to reduce the overall cycle time, the speed of said operation being greatly conditioned by the greater or smaller opening of the bag mouth.

[0011] The technical problem which is posed, therefore, is that of providing a bag filling cone for bag filling machines which is able to solve the aforementioned problems, or at least limit the negative effects thereof, so as to reduce the amount of time spent by the bag in the filling station and therefore reduce the overall machine cycle.

[0012] In connection with this problem, it is also required that the filling cone should be easy and inexpensive to produce and assemble and be able to be moved by automatic programming, control and command means.

[0013] These results are obtained according to the present invention by a filling cone according to the characteristic features of Claim 1 .

[0014] The use of movable wedge elements results in very fast and precise insertion of the filling cone mouth into the mouth of the bag, reducing the possibilities of errors with loss of material or machine stoppages and is also able to make full use of partial opening of the filling cone mouth in order to dispense the product even before the cone is completely open. Owing to the possibility of rapid insertion and increased opening of the cone mouth, the cone according to the invention is able to increase the volume of discharged product for the same duration of the bag filling step, resulting in a faster filling speed and therefore reduction in the overall time of the machine cycle.

[0015] The present invention also relates to a bag filling station for filling machines according to Claims 12 and a method of filling a bag in a filling station according to Claim 17.

[0016] Further details may be obtained from the following description of a nonlimiting example of embodiment of the subject of the present invention provided with reference to the attached drawings in which:

[0017] Fioure 1 : shows a schematic side view of the filling station with cone according to the invention upon arrival of a bag to be filled;

[0018] Figure 1 a: shows a schematic top plan view of the bag mouth open arrival of the bag in the filling station;

[0019] Figure 2: shows a schematic side view of the filling station with cone according to the invention during gripping of the top rim by gripping means of the filling station;

[0020] Fioure 2a: shows a schematic top plan view of the bag mouth during the step shown in Fig.2;

[0021] Fioure 3: shows a schematic side view of the filling station with cone according to the invention during insertion, into the bag mouth, of lateral means associated with the filling cone;

[0022] Figure 3a: shows a schematic top plan view of the bag mouth during the step shown in Fig.3;

[0023] Figure 4: shows a schematic side view of the filling station with cone according to the invention during initial opening of the cone mouth and the start of the bag filling;

[0024] Figure 4a shows a schematic top plan view of the bag mouth during the step shown in Fig.4;

[0025] Figure 5 shows a schematic side view of the filling station with cone according to the invention during retraction, from the bag mouth, of the lateral means associated with the filling cone and simultaneous further opening of the cone mouth;

[0026] Figure 5a shows a schematic top plan view of the bag mouth during the step shown in Fig.5;

[0027] Figure 6 shows a schematic side view of the filling station with cone according to the invention during closing of the dispensing mouth and its retraction from the bag mouth;

[0028] Figure 6a shows a schematic top plan view of the bag mouth during the step shown in Fig.6;

[0029] Figure 7 shows a schematic side view of the filling station with the grippers of the station arranged in a more spaced position, gripping the closed mouth of a bag with a larger width;

[0030] Figure 7a shows a schematic top plan view of the grippers and the bag mouth during the step shown in Fig.7;

[0031] Figure 8 shows a schematic side view of the filling station with cone according to the invention during release of the wider bag by the fixed grippers of the filling station.

[0032] As shown and assuming for the sake of easier description, a longitudinal direction X-X parallel to the widthwise dimension of the mouth of a bag 1 , a vertical direction Z-Z parallel to a direction of dispensing of the product and height of the cone, and a transverse direction Y-Y perpendicular to the other two directions, a preferred example of a filling cone 10 according to the invention comprises two half-shells 11 , 12 arranged opposite each other in the longitudinal direction and movable a between a relative minimum opening (closed) position of a bottom mouth 10a of the cone and a maximum opening position of the said cone mouth, for the sake of simplicity coinciding with the vertical axis Z-Z.

[0033] The two half-shells 11 ,12 preferably each have a lateral side wall 11 a, 12a and two longitudinal front walls 11 b,12b extending from the side wall towards the opposite half-shell. The two half-shells may be coupled together along the longitudinal walls 1 1 b, 12b and have complementary shapes, for example designed to be inserted inside each other or to be arranged offset with each other, so as to form the filling cone.

[0034] In the minimum opening configuration, the cone 10 has preferably an internal volume substantially in the form of a truncated pyramid, with the lateral side walls inclined and converging towards a central vertical axis of the cone.

[0035] Each half-shell 11 ,12 is mounted on a respective arm 11 c, 12c, one end of which is fixed to a top part of the half-shell and an opposite end of which is hinged with the filling station, so that each half-shell is able to rotate about a respective transverse axis 1 1d,12d away from the opposite half-shell so as to open the bottom dispensing mouth 10a, and towards the opposite halfshell, into the closed position of the dispensing mouth 10a.

[0036] The rotation of each half-shell 1 1 ,12 about the respective transverse axis 1 1 d,12d is performed by cone actuating means, not shown, for example an electric actuator which can be controlled by means of a control unit. The electric actuator may be the same for both the half-shells, for example of the brushless type, and have an output connected by means of a transmission chain to each half-shell, for synchronized actuation thereof. The transmission chain for synchronized actuation of the two half-shells preferably comprises a crank operated by the electrical actuator and coupled to a pair of connecting rods, each constrained to the transverse axis of rotation of a respective one of said half-shells, so that the movement of the crank is transmitted by means of the connecting rods to both the arms 1 1 a, 12c and causes the synchronized rotation of both the half-shells 11 ,12.

[0037] Two arms 1 1c, 12c have a length such that the rotation of the shells in the two opposite directions of rotation also causes, respectively:

[0038] - lowering of the bottom end of each half-shell in the vertical direction, when the half-shell is rotated away from the opposite half-shell in order to open the mouth 10a; and

[0039] - raising of the bottom end of each half-shell in the vertical direction, when the half-shell rotates in the direction towards the opposite half-shell in order to close the mouth 10a.

[0040] The cone 10 also comprises a pair of wedge elements 14 (Figs. 1 ,4), each arranged on the outside of a respective lateral side wall 1 1 a, 12a of the cone half-shells. Each wedge 14 is displaceable along the said side wall between a top retracted position and a bottom lowered position, where it projects from the bottom mouth 10a of the cone.

[0041] Each wedge 14 is preferably formed with an inclined surface 14a at its bottom end, having an inclination directed towards the vertical central axis. The wedge has (Fig. 3a), for example, a triangular-shaped cross-section with its base directed towards the respective side wall 11 b, 12b of the cone 10 and vertex directed outwards. This configuration is particularly advantageous for giving a substantially hexagonal shape to the top rim of the bag during the initial filling step.

[0042] Each wedge element 14 is displaceable between the top retracted position and the bottom projecting position upon operation of a respective actuating actuator 15, which comprises, for example, a stationary actuating part 15a fixed to the respective half-shell (in particular to the respective lateral side wall) and a movable actuated arm 15b which is connected to the respective wedge 14. The actuator 15 may be, for example, a pneumatic actuator or a linear electric actuator, which can be controlled by the cone control unit.

[0043] As will become clearer below, the actuating movements of the half-shells 11 ,12 and of the wedges 14 my be coordinated, for example by means of the filling cone control unit, so that the wedges move from the top raised position into the bottom lowered position, projecting from the bottom mouth of the cone, when the cone moves from the minimum opening position into a first open position of the dispensing mouth, so that, during an initial stage of the filling cycle, the wedges 14 initially tension the mouth 1a of the bag (Fig. 4a), with the dispensing mouth 10a only partially open and partially inserted in the bag mouth. The actuating movements of the half-shells 11 ,12 and wedges 14 may also be controlled so that the wedges 14 move from the bottom projecting position into the top raised position, when the cone 10 moves from said first open position into a second open position in which the dispensing mouth 10a is more open than in the first open position, with the bag mouth tensioned by the walls of the filling cone.

[0044] The filling cone is arranged in a station 100 for filling bags 1 , which comprises two pairs of gripping means, for example in the form of grippers 110, which are arranged opposite each other in the longitudinal direction X-X and can be opened and closed so as to hold the opposite longitudinal end edges of the bag mouth during filling and release the bag 1 at the end of filling.

[0045] Preferably, the pairs of gripping means 110 are movable towards and away from each other in the longitudinal direction X-X so as to set, during adjustment, a different position in the longitudinal direction X-X according to different widths of the bag mouth being handled and different relative maximum opening positions of the dispensing mouth 10a of the cone, in order to achieve correct gripping of the edges thereof, as shown in Figs. 7 and 8, and can be rotated about a horizontal axis so as to pass from a raised position of non-interference with the travel movement of the bag and a lowered position where the opposite vertical edges of the bag are gripped. The displacement of the gripping means may be performed by associated displacement means 16, preferably actuated by electric actuators with a brushless motor.

[0046] Preferably, each pair of gripping means 15 is designed to remain fixed during the opening and filling of the bag, speeding up further the filling cycle and simplifying the structure and control of the filling station. In addition, the fixed grippers may consist of a mechanical end-of-travel safety stop for limiting the opening rotation of a respective half-shell in the event of control system malfunctions.

[0047] The electric actuators of the half-shells 11 ,12 are in any case preferably able to control the degree of opening of each half-shell during its entire travel movement so that the maximum opening end-of-travel position may be electronically determined and set during adjustment by means of the control unit.

[0048] In some embodiments, the mobility of the gripping means towards / away from each other in the longitudinal direction may also be advantageously used in order to cause partial opening of the mouth of the bag 1 during an initial phase of the filling cycle; it is however preferable that the bag should arrive at the filling station already open, making use of the time during which it is transported towards the filling station 100. With reference to Figures 1-6, a filling method which uses the cone of the present invention may comprise the following steps:

[0049] - positioning a bag 1 in the filling station, with the mouth at least partially open in a position underneath the vertical axis of the filling cone, the bag 1 being held by the gripping means 15 of the station, which are arranged rotated and closed so as to grip the end edges of the top rim of the bag 1 ; - displacing the wedges 14 into the bottom position projecting from the mouth 10a of the cone, where the wedges are inserted inside the mouth of the bag (Figs. 3,3a);

[0050] - initially opening the cone (Figs. 4,4a), moving the half-shells 11 ,12 away from each other into a first open position, where each wedge 14 preferably substantially adheres to the inner side surface of the mouth 1a of the bag 1 , so that the mouth 1 a of the bag 1 is tensioned by the wedges 14;

[0051] - the rotation of the arms 11 for initial opening of the cone also causes the downward movement of the half-shells 11 ,12 so that the bottom mouth 10a of the cone enters inside the open bag mouth and starts dispensing the product inside the bag;

[0052] - displacing the wedges 14 in the raising direction along the side wall of the respective half-shell until the wedges 14 are retracted out of the bag, with

[0053] - simultaneous further opening rotation of the half-shells of the filling cone into a second more open position of the dispensing mouth (Figs. 5,5a) where the lateral side walls of each half-shell 11 ,12 are at the end of the opening travel movement (the opening end-of-travel position may electronically adjusted with a high degree of precision so as to bring the half-shells 11 ,12 - or the wedges 14 during initial opening of the cone - substantially up against the grippers 110 which retain the side folds, but without coming into contact with them);

[0054] - completing rapid dispensing of the product until the bag is filled;

[0055] - rotating the arms 11c in an anti-clockwise direction 11c and moving the shells back into the initial position for starting a new filling cycle.

[0056] As can be seen in Figs. 4a, 5a, in the first open position, the filling cone causes a first opening movement of the bag mouth which is tensioned by the wedges which for example impart a substantially hexagonal shape to the bag mouth.

[0057] In the second open position, i.e. with the half-shells in the opening end-of- travel position for the set bag size, a second greater opening of the cone mouth 10a and of the bag mouth is performed, with the bag mouth being tensioned by the filling cone walls.

[0058] In other words, the filling cone is configured so that the wedges move:

[0059] - from the top raised position into the bottom lowered position, projecting form the bottom mouth of the cone, when the cone moves from the minimum opening (closed) position into a first open position of its mouth, and - from the bottom projecting position into the retracted top position when the cone moves from said first open position into a second open position, with opening of the mouth 10a of the filling cone greater than the opening in the first opening position, so as to allow complete opening of the bag mouth tensioned by the walls of the filling cone.

[0060] The raising of the cones, following initial insertion of the shells in the bag mouth, enables a greater opening of the bag mouth to be obtained without the need to raise the half-cones, resulting in a corresponding substantial increase in the speed of dispensing of the product to be packaged and therefore a reduction in the overall cycle time, thereby increasing the productivity.

[0061] According to preferred embodiments, positioning of the bag in the filling station may take place as follows:

[0062] - feeding a bag 1 to the filling machine;

[0063] - transporting the bag to the filling station, by means of the transport means for example comprising retaining means displaceable in the longitudinal direction and able to be moved towards and away from each other in order to open the mouth 1a of the bag 1 , assisted by opening suction cups movable towards and away for each other in a direction transverse to the bag mouth, so as to open at least partially the mouth of the bag 1 during transport;

[0064] - arrival of the bag at the filling station, with the mouth partially open, in the position underneath the vertical axis of the filling cone;

[0065] - gripping of the edges of the top rim by the gripping means 110 of the station, arranged in a predefined longitudinal relative position for gripping only the end edges of the top rim of the bag;

[0066] - releasing of the bag by the transport means.

[0067] Therefore, the transport of the bag to the filling station is performed preferably by the transport means which cooperate with opening means so as to open at least partially the bag mouth during transport, thus making the best possible use of the transport time and speeding up the filling cycle.

[0068] It is therefore clear how the possibility of increased opening of the cone mouth allows the cone according to the invention to increase the volume of product discharged during the same bag filling step, resulting in a faster filling speed and therefore reduction in the overall time of the machine cycle. In addition, the use of the movable wedges results in very precise insertion of the filling cone mouth into the bag mouth, reducing the possibilities of errors with loss of material or machine stoppages, and also fully exploits opening of the bag mouth which is tensioned by the wedges so as to achieve optimum dispensing even before the filling cone is completely open. Although described in connection with a number of embodiments and a number of preferred examples of implementation of the invention, it is understood that the scope of protection of the present patent is determined solely by the claims below.

Claims

CLAIMS1. Filling cone (10) for a filling station (100) for filling bags (1 ), comprising:- two half-shells (11 ,12) arranged opposite each other in a longitudinal direction (X-X) parallel, in use, to the widthwise dimension of a bag to be filled, the two half-shells being coupled together so as to define walls (12a,12b,11a,11b) of the cone and a bottom dispensing mouth (10a) of the cone, the two half-shells (11 ,12) each having a lateral side wall (11 a, 12a) of the cone, the two lateral side walls (11 a, 12a) being situated opposite each other in the longitudinal direction (X-X); the two half-shells (11 ,12) being movable between a relative minimum opening position of the bottom mouth (10a) of the cone and a maximum opening position of the bottom dispensing mouth (10a) of the cone; characterized in that it comprises- a pair of wedge elements (14), each arranged on the outside of a respective lateral side wall (11 a, 12a) of the cone and displaceable with respect to the said side wall between a top raised position and a bottom lowered position, projecting from the bottom dispensing mouth (10a) of the cone and in that the displacement of the wedges is independent of the opening / closing movement of the cone.

2. Filling cone according to Claim 1 , configured such that the wedges (14) are controlled to move:- from the top raised position into the bottom lowered position, projecting from the bottom mouth of the cone, when the cone moves from the minimum opening position into a first open position of the dispensing mouth, and- from the bottom projecting position towards the top raised position, when the cone moves from said first open position into a second open position where there is greater opening of the filling cone mouth than in the first open position.

3. Filling cone according to one of the preceding claims, characterized in that it comprises actuating means (15) for displaceably actuating each wedge (14) between the raised position and the lowered position.

4. Filling cone according to Claim 3, characterized in that said actuating means (15) comprise a stationary part (15a) fixed to the respective half-shell and a movable arm (15b) coupled to the respective wedge (14).

5. Filling cone according to Claim 4, characterized in that said actuatingmeans comprise a pneumatic or electric actuator for each wedge.

6. Filling cone according to one of the preceding claims, wherein each half-shell is supported by an arm hinged on a respective transverse axis (11d,12d), the rotation of each arm about the respective transverse axis causing a movement of the half-shells (11 ,12) towards / away from each other, in order open / close the dispensing mouth (10a) and a vertical upwards / downward movement of said dispensing mouth (10a).

7. Filling cone according to one of the preceding claims, further comprising actuating means for opening / closing the half-shells (11 ,12), preferably comprising a single electric actuator connected to the respective arm (11c) of both the half-shells by means of a transmission chain for synchronized actuation of the two half-shells, the electric actuator being optionally of the brushless motor type.

8. Filling cone according to the preceding claim, wherein the transmission chain comprises a crank actuated by the electric actuator and coupled to a pair of connecting rods, each constrained to the transverse axis of rotation of a respective one of said half-shells.

9. Filling cone according to one of the preceding claims, further comprising a control unit which coordinates the opening and closing movement of the filling cone mouth with the displacement of the wedges (14).

10. Filling cone according to one of the preceding claims, wherein each wedge (14) has a substantially triangular cross-section with the vertex pointing outwards.

11. Filling cone according to the preceding claim, wherein each wedge has an inclined surface (14a) at a bottom end thereof.

12. Station (100) for filling bags (1) for a filling machine, comprising a filling cone (10) according to one of the preceding claims and gripping means for holding the bag during filling.

13. Filling station according to Claim 12, characterized in that said gripping means are displaceable towards / away from each other in the longitudinal direction (X-X), so as to vary a relative distance in the longitudinal direction (X-X) according to different widths of the bag being handled.

14. Filling station according to Claim 13, characterized in that said gripping means are displaced by an electric actuating system, preferablycomprising a brushless electric motor.

15. Filling station according to one of Claims 12-14, characterized in that said gripping means comprise grippers (110) situated opposite each in the longitudinal direction (X-X) and able to be operated so as to open / close around the opposite end edges of the bag mouth.

16. Filling station according to one of Claims 12-15, wherein the gripping means are kept in a fixed position in the longitudinal direction during opening of the filling cone and dispensing of the product from the dispensing mouth.

17. Method for filling a bag (1 ) in a filling station (100) of a filling machine according to one of Claims 12-16, comprising the steps of:- positioning a bag (1) in the filling station, with the partially open mouth in a position underneath the filling cone, the bag (1) being held by the gripping means (110) of the station, which are arranged so as to grip the end edges of the top rim of the bag (1 );- displacing the wedge elements (14) into the bottom position, projecting from the cone mouth, with insertion of the wedges inside the mouth (1a) of the bag (1);- initially opening the filling cone, moving the half-shells (11 ,12) away from each other into a first open position, with the downward movement of the half-shells (11 ,12) so that the bottom mouth (10a) of the cone enters inside the open bag mouth and starts dispensing the product inside the bag;- displacing the wedges (14) in the raising direction along the side wall of the respective half-shell, until the wedges are retracted out of the bag, with simultaneous further opening rotation of the half-shells of the filling cone, into a second open position of the dispensing mouth, where the dispensing mouth is fully open and the lateral side walls of each half-shell (11 ,12) are at a maximum set distance and tension the bag mouth;- completing dispensing of the predefined quantity of product inside the bag;- moving the half-shells into the minimum opening position of the dispensing mouth.

18. Method according to Claim 17, wherein, in the first open position, the filling cone causes a first opening movement of the bag mouth which is tensioned by the wedges (14) which impart a first shape to the bag mouth, preferably a substantially hexagonal shape; and wherein, in the second open position, a second, greater, opening movement of the cone mouth (10a) is performed, whereby the bag mouth istensioned by the filling cone walls and assumes a second, different shape, preferably a substantially rectangular shape.

19. Method according to one of Claims 17 and 18, wherein the positioning of the bag in the filling station involves the following preliminary steps:- feeding the bag (1 ) to the machine;- transporting the bag with the mouth at least partially open into the position underneath the vertical axis of the filling cone;- gripping of the edges of the top rim of the bag by the gripping means of the station, arranged in a predefined relative position in the longitudinal direction, adjusted according to the width of the bag mouth.

20. Method according to the preceding claim, wherein transportation of the bag is performed by transporting means comprising holding means displaceable in the longitudinal direction and able to be operated towards and away from each other so as to open at least partially the mouth of the bag during transportation, assisted by further opening means movable towards and away from each other in a direction transverse to the longitudinal widthwise direction of movement of the bag.