GB2078191A - Bag-filling Machine - Google Patents

Abstract

A machine for filling bags with particulate material comprises a plurality of filling spouts 17 equi-angularly spaced around the periphery of a rotary indexing table 14. During operation of the table 14 each filling spout 17 is moved successively to a number of work stations S1 to S16. At a first one of these stations S1 a bag to be filled is suspended from each filling spout 17 in turn; thereafter each filling spout 17 with its bag is taken to one or more dispension devices 23, 24, 25 which dispense material into the bag through the filling spout 17. After being filled, each bag is released from its filling spout 17. Preferably, three dispensing devices 23, 24 25 are provided, the most downstream of which operates as a top-up dispenser 25 under the control of a bag-weighing machine 37 disposed immediately upstream of the top-up dispenser 25. Stations 4-10 are provided with a single common bag vibrator. <IMAGE>

Description

SPECIFICATION Bag-Filling Machine The present invention relates to machines for filling bags with particulate materials and in particular, but not exclusively to machines for filling bags with non-free-flowing substances such as flour.

According to the present invention, there is provided a machine for filling bags with particulate material, said machine comprising conveying means arranged to convey a plurality of filling spouts around a closed path such as to take the spouts one after another successively past a number of work stations of the machine, means arranged to suspend a respective bag from each filling spout in turn at a first said work station and to release each bag from its corresponding spout at a second said work station, and means for at least partially filling each bag through the corresponding filling spout while the bag is suspended from that spout.

Preferably the said means for at least partially filling each bag comprises two or more dispensing devices located at respective work-stations and arranged to operate successively to dispense material into each bag as that bag is successively presented to the dispensing devices. The most downstream dispensing device can advantageously serve as a "top-up" dispenser giving fine control of the final weight of material dispensed into the bag and operating under the control of a weighing machine disposed immediately prior to the top-up dispenser. As each bag is moved to the weighing machine, it is released from its filling spout, weighed, and then re-suspended, the measured bag weight being used to control the top-up dispenser during its subsequent dispensing operation.Any bags which are found by the weighing machine to be outside predetermined weight limits (corresponding to the top up capabilities of the top-up dispenser) are rejected into a disposal bin.

Where the particulate material is a non freeflowing substance such as flour, each of the bagfilling means advantageously comprises an auger positioned in a close tolerance tube and so arranged that a predetermined angular rotation of the auger dispenses a predetermined volume of material.

A bag-filling machine which embodies the invention and which is arranged to fill bags with a non free-flowing particulate material, will now be described with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a plan view of the machine; and Figure 2 is a side view of the machine in the direction of arrow A of Figure 1, various components of the machine being omitted for the sake of clarity.

As shown in the drawings, the bag-filling machine comprises a positively indexing, rotary, intermittent-motion turret 10 which is arranged to fill a bag with particulate material and pass it to a vibratory link conveyor 1 2. This conveyor 1 2 then transports the filled bag from the filling turret 10 to a sealing turret (not shown) where the bag is folded and sealed.

The filling turret 10 comprises a circular table provided with radial ribs 11. The table 14 is mounted for rotation about a vertical axis C-C (Fig. 2) on a stand 1 3 which is centrally upstanding from a fixed base 1 5. The table 14 is rotationally indexed in the direction of dashed arrow B (Fig. 1) by an electric motor (not shown).

At each indexing step the table 14 is angularly displaced through 22210 so that after sixteen such steps the table has completed one revolution.

Sixteen filling spouts 1 7 are equi-angularly spaced around the periphery of the table 14 with their lower end portions 1 8 projecting below the table; in Figure 2 only two filling spouts 17 are shown for reasons of clarity. The filling spouts 1 7 are shaped as hoppers with their wider ends open upwardly. As the filling turret 10 is repeatedly indexed, each filling spout 1 7 is moved in turn to each of sixteen work stations S1 to S16 located around the table 14 in stationary relation to the base 1 5. The mid-positions of these work stations S1 to S16 are indicated by chain dashed radial lines in Figure 1.

At the first work station S1 a bag feeding mechanism 20 is arranged to take bags one at a time from a bag magazine 21 and place them around the lower end portions 1 8 of successive ones of the filling spouts 1 7 as these spouts are moved in turn to the work station S1.Each bag is held suspended from a respective one of the spouts 1 7 by means of a bag clamping mechanism 1 9 associated with that spout, this mechanism being in the form of pivoted clamping arms selectively operable to clamp or release the bag; the two mechanisms 19 shown in Figure 2 are illustrated in their clamped positions holding respective bags 50 on their corresponding filling spouts 1 7. The principles of such a bag feeding and suspension arrangement are well known and are exhibited, for example, by the Sealtite (Registered Trade Mark) Mark Ill bag feed machine manufactured by Bristol Packaging Machines Limited of Great Britain.

The lower portion 1 8 of each spout 17 is positioned between a respective pair of plates 22 arranged to move with the table 1 4. These plates facilitate the transportation between work stations of a bag clamped on the corresponding spout 17 and in particular, prevent undue back and forth swaying of the bag as it is accelerated or de-accelerated.

A sensor 9 is provided intermediate the work stations S2 and S3, the purpose of this sensor 9 being to detect the presence of a bag suspended from each spout 1 7 as that spout is moved between the work stations S2 and S3.

Located at work stations S3, S6, and S13 are respective auger dispensing devices 23, 24 and 25 arranged to dispense a predetermined amount of particulate material into the top of the filling spout 1 7 located immediately below a dispensing tube 26 of each device. The dispensing devices 23 and 24 are each arranged to dispense approximately 473% of the total amount of particulate material which each bag is intended to hold, while the dispensing device 25 acts as a "top-up" device arranged to dispense the remaining 5% of material required to fill each bag.

The dispensing devices 23, 24, and 25 are mounted in alignment with the work stations S3, S6 and S13 respectively either directly from floor level or by means of an overhead structure (not shown).

Each of the dispensing devices 23, 24 and 25 comprises an auger located within a close tolerance tube and so arranged that a predetermined angular rotation of the auger dispenses a predetermined volume of material.

Each dispensing device is itself supplied with material to be dispensed via a respective pipe (not shown) from a bulk hopper.

The fourth, fifth, sixth, seventh, eighth, ninth and tenth work stations S4, S5, S6, S7, S8, S9 and S10, are provided with a single, common bag vibrator arranged to vibrate the bags partially filled by the dispensing devices 23 and 24.

Suitable vibrators are well known and will not be described in detail herein.

The work station S1 1 is designed to provide an "escape route" for any material which may have been spilled around the bag.

The work station S12 is provided with a weighing machine 37. As each bag is moved in turn to the work station S12, it is temporarily released from its corresponding spout 17 to come to rest on the weigh plate of the weighing machine 37. This weighing machine 37 then accurately determines how much more material needs to be added to the bag to complete its filling, this information being used to control the operation of the "top-up" dispensing device 25 at station S13 or to result in rejection of the bag (by release from its spout 1 7 into a disposal bin at station S13) if the bag weight recorded is outside the "top-up" capabilities of the dispensing device 25.

At work station S14 a correctly filled bag is arranged to be released from it spout 1 7 to drop onto a dead plate (not shown) located below the table 14. A transfer device 31 mounted on fixed structure of the machine is arranged to transfer bags dropped onto this dead plate to the conveyor 12. The operation of the bag clamping mechanisms 19 at the work station S14 is effected mechanically by means of a static ramp 38 arranged to engage an actuating lever of each mechanism 1 9 as the corresponding filling spout 17 is moved to the station S14.

The operation of each bag clamping mechanism 19 at the work station 81,812 and S13 is, however, effected pneumatically in dependence on the output of a non-contact sensor (not used) arranged to provide an indication of the movement of the spout 1 7 to each of the work stations S1, S12 and S13. The outputs of these non-contact sensors are in fact connected to a microprocessor control unit (not shown) arranged to control pneumatic operating means for actuatinq the mechanisms 19. Also connected to the control unit are the outputs of the sensor 9 and of the weighing machine 37.The microprocessor control unit is arranged to control not only the operation of the bag clamping devices 19 at stations S1, S12 and S13, but also the operation of the dispensing devices 23, 24, 25, and of the transfer device 31. The control unit is further arranged to stop the machine if the sensor 9 indicates that six successive filling spouts 1 7 are not carrying bags.

The operation of the filling turret 10 under the control of its microprocessor control unit will now be described taking each station S1 to S16 in turn.

Station S1--A bag is taken from the magazine 21 and positioned about the filling spout 1 7 located at the station S1 by the device 20; the bag is clamped in position.

Between Stations S2, S3--The bag sensor 9 detects the presence or absence of a bag on the corresponding filling spout 17, this information being used to control the subsequent operation of the dispensing devices 23 and 24 when, following the indexing of the table 14, this spout 17 is positioned in turn beneath the dispensing devices. The absence of six successive bags causes the control unit to stop the machine.

Station Se--The first dispensing device 23 dispenses approximately 47.5% of the final material weight into the bag clamped to the filling spout 1 7 positioned below the dispensing tube 26 of the device 23. If the sensor 9 between stations S2 and S3 has previously indicated the absence of a bag on the spout 17, then the dispensing device 23 is inhibited for the appropriate period.

Station S4, 85-The bag vibrator serves to vibrate the partially filled bags to firm up and release air trapped in their contents.

Station SG--The second dispensing device 24 adds a further 47.5% of the final material weight to a bag, (where present). The bag vibrator continues to vibrate the bag during filling.

Stations S7, 88, S9, 81 0The bag vibrator serves to vibrate the nearly full bags to release trapped air and to firm and square the bags to their required size and shape.

Station 811-Any spilled product is allowed to escape prior to transfer of the bag to the check weighing machine 37 at station S12.

Station S12--The nearly full bags are released onto the weigh plate of the weighing machine 37. The weighing machine accurately determines how much material needs to be added to bring a bag up to a specified weight; if the required additional material weight is outside the "top-up" limits of the "top-up" dispensing device 25, a weight reject signal is generated to prevent subsequent operation of the dispensing device 25 and to cause release of the bag at station S13. After a bag has been weighed it is re-clamped onto its filling spout 17.

Station 813The "top-up" dispensing device 25 operates to fill a bag with the amount of material needed to bring the bag up to weight, this amount having been previously determined by the weighing machine 37 at station S12. If the bag was found unacceptable by weight station S12, then the dispensing device 25 does not operate; instead, the bag is released from its spout 17 to drop down into a disposal bin.

Station S14--Topped up bags are transferred onto the conveyor 12 by the transfer device 31 which operates on a continuous, non-selective basis.

Station 815-No operation takes place.

Station 816-No operation takes place.

The filled bags transferred onto the conveyor 12 then pass to the sealing turret to be sealed in known manner.

The described filling turret 10 can be used to fill block bottomed gussetted bags with flour at a rate of up to 80 bags a minute.

Various modifications are of course possible to the described bag-filling machine; thus, for exampie, the number and form of the dispensing devices can be changed to suit the characteristics of the material with which the bags are to be filled. Furthermore, the amount of material dispensed by each dispensing device may differ from that indicated though, preferably, the dispensing device(s) upstream of the most downstream one are arranged to dispense at least 90% by weight of the required amount of material.

Claims (12)

Claims

1. A machine for filling bags with particulate material, said machine comprising conveying means arranged to convey a plurality of filling spouts around a closed path such as to take the spouts one after another successively past a number of work stations of the machine, means arranged to suspend a respective bag from each filling spout in turn at a first said work station and to release each bag from its corresponding spout at a second work station, and means for at least partially filling each bag through the corresponding filling spout while the bag is suspended from that spout.

2. A bag-filling machine according to Claim 1, wherein said means for at least partially filling each bag comprises two or more dispensing devices located respective work stations and arranged to operate successively to dispense material into each bag as that bag is successively presented to the dispensing devices in the course of operation of said conveying means.

3. A bag-filling machine according to Claim 2, further comprising a weighing machine arranged to weigh each bag prior to the dispensing of material into that bag by the most downstream of the dispensing devices, considered in relation to the direction of conveyance of the filling spout from said first to said second work station, but subsequent to the dispensing of material into the bag by the preceding said dispensing device, the amount of material dispensed by said mostdownstream dispensing device into a bag being controlled in dependence on the weight of that bag as measured by said weighing machine.

4. A bag-filling machine according to Claim 3, wherein said weighing machine is disposed at a said work station intermediate the work station whereat the said most-downstream dispensing device is located and the work station whereat the preceding dispensing device is located, said bag-filling machine further including means arranged to cause each bag to be released in turn from the corresponding filling spout for weighing at the weighing-machine work station and to be subsequently re-suspended from the filling spout after weighing has been completed.

5. A bag-filling machine according to Claim 3 or Claim 4, wherein the dispensing of material into a bag by the most-downstream dispensing device is prevented if the weight of that bag as determined by said weighing machine is outside predetermined limits, the bag-filling machine including means for rejecting a bag found to be outside said weight limits by the weighing.

machine.

6. A bag-filling machine according to Claim 2, wherein three of said dispensing devices are provided at respective work stations intermediate said first and second stations, the two most upstream dispensing devices, considered relative to the direction of conveyance of the filling spouts from said first to said second work stations, being together arranged to dispense at least 90% by weight of the total amount of particulate material which it is desired to put into each bag, the remaining percentage of material being dispensed by the most downstream dispensing device in dependence on the weight of each bag in turn as determined by a weighing machine disposed at said work station intermediate the work stations of the two most downstream dispensing devices, the bag-filling machine being arranged to release and subsequently re-suspend each bag from its filling spout when at the weighing-machine work station whereby to enable an accurate determination of the weight of each bag to be made by the weighing machine.

7. A bag-filling machine according to Claim 6, wherein the two most upstream dispensing devices are each arranged to dispense 4721% of the total amount of material required to be piaced into a bag.

8. A bag-filling machine according to any one of Claims 3 to 7, including vibrator means disposed intermediate the most upstream dispensing device and the weighing machine and operative to vibrate each bag to settle its contents and release trapped air.

9. A bag-filling machine according to any one of Claims 2 to 8, including means responsive to the non suspension of a bag from said filling spout at said first work station, to prevent operation of each dispensing device in turn as that filling spout is presented thereto.

10. A bag-filling machine according to any one of Claims 2 to 9, wherein at least one said dispensing device comprises an auger positioned in a close tolerance tube and so arranged that a predetermined angular rotation of the auger dispenses a predetermined volume of material.

11. A bag-filling machine according to any one of the preceding claims, wherein said filling spouts are equi-angularly spaced around the periphery of a rotary indexing table constituting said conveying means.

12. A machine for filling bags with particulate material, said machine being substantially as hereinbefore described with reference to the accompanying drawings.