Product discharge control device for a form-fill-seal machine

Abstract

The invention relates to a discharge control device, comprising a hopper (1) receiving a metered product amount where it is deposited, discharge control elements (3) movable between a closed position and an open position by a driving mechanism, and a fill tube (2) connecting the discharge control device with a fill nozzle of the form-fill-seal machine whereby a bag is filled with product, wherein the driving mechanism of the discharge control elements (3) comprise a motor (7) driving the movement of one of the discharge control elements (3), and a synchronizing connecting rod (9) synchronizing the movement of the discharge control element (3) driven by the motor (7) with the other discharge control element (3). The invention allows filling bags reliably and more quickly.

Claims

1. Product discharge control device for a form-fill-seal machine, comprising a hopper (1) receiving a metered product amount where it is deposited, discharge control elements (3) movable between a closed position and an open position by a driving means, and a fill tube (2) connecting the discharge control device with a fill nozzle of the form-fill-seal machine whereby a bag is filled with product, characterized in that the driving means of the discharge control elements (3) comprise a motor (7) driving the movement of one of the discharge control elements (3), and a synchronizing connecting rod (9) synchronizing the movement of the discharge control element (3) driven by the motor (7) with the other discharge control element (3), wherein said driving means also comprise first and second levers (5, 6) connected by means of said synchronizing connecting rod (9), each integral with a shaft for moving each of said discharge control elements (3), and the movement of which is driven by means of a drive belt (10) located between the output shaft of the motor (7) and one of said levers (5, 6).

2. Product discharge control device for a form-fill-seal machine according to claim 1, wherein said driving means also comprise first and second levers (5, 6) connected by means of said synchronizing connecting rod (9), each integral with a shaft for moving each of said discharge control elements (3), and the movement of which is driven by means of a second connecting rod (4) and a crank (4, 8).

3. Product discharge control device for a form-fill-seal machine according to claim 2, wherein the crank (8) is connected to the output shaft of a drive motor (7).

4. Product discharge control device for a form-fill-seal machine according to claim 1, wherein when the discharge control elements (3) are in the closed position, said crank (8) and said second connecting rod (4) are in a dead center position.

5. Product discharge control device for a form-fill-seal machine according to claim 1, wherein said open position of said discharge control elements (3) has an angle of opening comprised between 50 and 90.

6. Product discharge control device for a form-fill-seal machine according to claim 1, wherein said discharge control elements (3) adopt different open positions during the discharge cycle.

7. Product discharge control device for a form-fill-seal machine according to claim 6, wherein said discharge control elements (3) adopt a given first open position and then a more open position during the discharge cycle.

8. Product discharge control device for a form-fill-seal machine according to claim 1, wherein said motor (7) is a servomotor (7).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) To better understand the preceding description, a set of drawings is attached in which a practical embodiment is schematically depicted by way of non-limiting example.

(2) FIG. 1 is a perspective view of the product discharge control device according to the present invention;

(3) FIGS. 2 and 3 are elevational views of the product discharge control device according to the present invention in the open position and in the closed position of the discharge control elements;

(4) FIG. 4 is an elevational view of the driving means of the product discharge control device of the present invention according to a second embodiment; and

(5) FIG. 5 is an elevational view of the driving means of the product discharge control device of the present invention according to a third embodiment.

DESCRIPTION OF A PREFERRED EMBODIMENT

(6) The drawings depict the product discharge control device according to the present invention, comprising a hopper 1 where the metered product amount used for filling the bag is discharged and a fill tube 2, connecting the discharge control device according to the present invention to the fill nozzle of the form-fill-seal machine.

(7) The control device according to the present invention also comprises discharge control elements 3 that are movable between an open position in which product discharge is allowed, and a closed position in which product discharge is prevented, which allows receiving in this closed position a new metered product amount discharge released by the metering and weighing system located upstream.

(8) Said discharge control elements 3 are arranged between the hopper 1 and the fill tube 2, as seen in the drawings, and allow controlling product discharge towards the fill nozzle of the form-fill-seal machine.

(9) According to the depicted embodiment, said discharge control elements 3 are swinging blades, although they could be any suitable discharge control element that is equivalent in terms of function.

(10) The driving means which allow the movement of said discharge control elements 3 comprise a connecting rod-crank mechanism that will be described below, driven by means of a motor 7, for example, by means of a servomotor.

(11) Said connecting rod-crank mechanism comprises a crank 8 connected to the output shaft of the motor 7 and a second connecting rod 4 connected thereto at one of its ends. The other opposite end of this second connecting rod 4 is in turn connected to one of the ends of the lever 5 integral with the rotating shaft of one of the discharge control elements 3. The rotational movement of the first lever 5 is transmitted to the second lever 6, which is integral with the rotating shaft of the second of the discharge control elements 3, in a synchronous manner by means of the synchronizing connecting rod 9.

(12) Advantageously, when the discharge control elements 3 are in the closed position, said crank 8 and said connecting rod second 4 are in a dead center position, i.e., in the position defined by the kinematics of this mechanism, in which an increase in rotation of the crank 8 in the same direction makes the second connecting rod 4 move in the direction opposite the one in which it was moving up until this time, which allows adjusting the position of the discharge control elements on the discharge hopper outlet profile, without any collisions occurring at the closing point, since the connecting rod-crank mechanism itself limits the maximum angular position the discharge control elements 3 reach with respect to the discharge hopper outlet profile.

(13) It should be indicated that the discharge control elements 3 can also be placed in different positions of the angle defined by said discharge control elements 3 during the product discharge cycle to obtain the shortest discharge time of all the product contents. Said positions of the discharge control elements can be fixed during the entire discharge cycle, or they can be variable and controlled by the automaton effecting discharge control during this cycle.

(14) Preferably, the angle defined by said discharge control elements 3 with respect to the horizontal, indicated in FIGS. 2 and 3 by means of the letter a, is preferably comprised between 50 and 90.

(15) The operation of the discharge control device according to the present invention is as described below.

(16) In the closed position, in the dead center position of the connecting rod-crank mechanism, the hopper 1 is filled with the metered product amount to be filled or discharged into the bag.

(17) In this closed position of the discharge control elements 3, the product is retained in the hopper 1, preventing it from being passed on to the fill tube 2.

(18) When the form-fill-seal machine located downstream gives the discharge order, the discharge control elements 3 move following the opening cycle pre-established by the control system for discharging the metered product amount in a controlled manner.

(19) The movement of the discharge control elements 3 is achieved by means of driving the connecting rod-crank mechanism described above by means of the motor 7.

(20) Once the desired product amount has been discharged, the discharge control elements 3 move to the closed position following the closing cycle pre-established by the control system, also by means of the connecting rod-crank mechanism and the motor 7.

(21) The angular movement trajectory (angular positions and speeds) of the discharge control elements during the opening and closing cycle can be programmed and/or adjusted by means of the control automaton for the purpose of obtaining the shortest time for the complete metered product amount discharge.

(22) Then from the closed position of the discharge control elements 3, the cycle is repeated again as soon as the device receives a new metered product amount, and the form-fill-seal machine requests a new discharge.

(23) The cycle described above is obviously performed continuously, many times at a high speed.

(24) FIG. 4 shows a second embodiment of the discharge control device according to the present invention.

(25) For the sake of simplicity, the same reference numbers are used to indicate elements equivalent to the preceding embodiment. It should furthermore be indicated that only the driving means of the discharge control elements are different in this embodiment, the remaining elements being the same as in the first embodiment.

(26) In this embodiment, the driving means of the discharge control elements also comprise first and second levers 5, 6 connected by means of said synchronizing connecting rod 9, each integral with a shaft for moving each of said discharge control elements 3, and the movement of which is driven by means of a drive belt 10 located between the output shaft of the motor 7, preferably a servomotor, and one of said levers 5, 6.

(27) FIG. 5 shows a third embodiment of the discharge control device according to the present invention.

(28) Like in the preceding case, for the sake of simplicity, the same reference numbers are used to indicate elements equivalent to the preceding embodiments. It should furthermore be indicated that only the driving means of the discharge control elements are different in this embodiment, the remaining elements being the same as in the first and second embodiments.

(29) In this third embodiment, the driving means also comprise first and second levers 5, 6 connected by means of said synchronizing connecting rod 9, each integral with a shaft for moving each of said discharge control elements 3, and the movement of which is driven by means of the output shaft of the motor 7 directly driving one of said levers 5, 6.

(30) Although reference has been made to a specific embodiment of the invention, it is obvious for a person skilled in the art that the discharge control device described is susceptible to a number of variations and modifications and that all the mentioned details can be replaced with other technically equivalent ones without departing from the scope of protection defined by the attached claims.