Device for filling sacks

Abstract

 Device for filling sacks comprising a frame, a number of sack holders (3) movable by a conveyor device (2) connected with said frame along a moving belt, whereby the moving belt extends past at least one sack feeding station (4) close to a sack feeding device (5), a sack filling station (10) and a discharge station (7), and whereby said sack feeding device (5) is provided with a supply holder (25) accommodating sacks in folded state, a first and second suction nozzle connected to a moving device which moving device is coupled with said conveyor device for synchronous movement with the same, and which can make said first suction nozzle move between said supply holder where it can grip a sack on one side and said sack feeding station and make said first and second suction nozzle move towards and away from one another at least close to said sack feeding station. The sack holders (3) can support the sacks internally and the moving device is arranged such that it can in addition move the suction nozzles in their movement away from one another over a distance in the order of magnitude of the sack length transversely to this movement in the direction towards a sack holder present in the sack feeding station (4).

Description

[0001] The invention relates to a device for filling sacks comprising a frame, a number of sack holders movable by a conveyor device connected with said frame along a moving belt, whereby the moving belt extends past at least one _'sack feeding station close to a sack feeding device, a sack filling station and a discharge station, and whereby said sack feeding device is provided with a supply holder accommodating sacks in folded state, a first and second suction nozzle connected to a moving device which moving device is coupled with said conveyor device for synchronous movement with the same, and which can make said first suction nozzle move between said supply holder where it can grip a sack on one side and said sack feeding station and make said first and second suction nozzle move towards and away from one another at least close to said sack feeding station.

[0002] Such a device for filling sacks with potting compost is known. The sacks filled with compost are used as cultivating containers for young plants and the like.

[0003] In this known device the suction nozzles are each formed by the end of a suction pipe which is guided relative to the frame in a reciprocal movement by means of a carriage. In the end position of the suction nozzles moved away from one another the first suction nozzle can pivot to the sack holder and there grip firmly a folded sack through suction. After the first suction nozzle has pivoted back the suction nozzles move with their carriages towards one another. When the auction nozzles have come close to each other the second suction nozzle applies suction on the opposite side of the sack. During the subsequent moving apart of the auction nozzles the sack is opened and a spreading device is inserted into the sack from above. This spreading device opens the sack further and takes the sack over from the suction nozzles. A sack holder is subsequently moved below the spreading device and the spreading device places the sack in the sack holder. The sack is held in place in the sack holder by means of curved needles. This device operates intermittently and because of the large number of movable parts has a complicated construction.

[0004] The object of the invention is to produce more simply a device of the kind set forth in the preamble.

[0005] This object is achieved in a device according to the invention in that the sack holders can support the sacks internally and the moving device is arranged such that it can in addition move the suction nozzles in their movement away from one another over a distance in the order of magnitude of the sack length transversely to this movement in the direction towards a sack holder present in the sack feeding station. As a result the suction nozzles can open the sack and arrange it over the sack holder in one continuous movement. Owing to this combined action the device can take a much simpler form and moreover operate more rapidly. It is hereby possible to make the sack holders move continuously, which also results in a simplifying of the device.

[0006] A particularly advantageous embodiment of the device is obtained when the moving device comprises two mirror symmetrical endless flexible members, guided around guide wheels such as chains, arranged on either side of the position of a sack holder in the -sack feeding station, having parts diverging relative to one another in the direction of said sack holder, when the suction nozzles are each firmly connected with one of these members and are linked by a coupling allowing rotation and a flexible hose with a suction device. In this embodiment the suction nozzles perform a continuous, even, progressive movement, which, in combination with the progressive movement of the conveyor device produces a particularly effective apparatus, which is moreover suitable for very high operating speeds.

[0007] A further favourable embodiment is obtained when the supply holder is arranged close to another part of the flexible member bearing the first suction nozzle and can support the folded sacks in a row transversely on this part. As the first suction nozzle moves past the supply holder the former grips onto the first sack in the row through suction and carries it along to the place where the second suction nozzle can grip on the other side.

[0008] The first suction nozzle grips the first sack in the row in a reliable manner at the desired place when, according to the invention, the supply holder is provided with a screen covering the foremost sack in the row as far as a portion close to the open side.

[0009] Accurate gripping of the sack by the second suction nozzle at the desired place, and not sooner than required, is also ensured according to the invention by a screen extending partially from the supply holder parallel to the member bearing the first suction nozzle, said screen having an end edge close to the place where the movement of the suc_- tion nozzles directed away from each other begins.

[0010] According to a further development of the invention reliable operation under difficult conditions is also obtained by a number of spreading fingers which are located for movement relative to the sack holder in the sack feeding station between a pick-up position, in which said fingers with ends moved towards one another are at an interval from the sack holder, and a spread position in which the fingers with ends remote from one another are next to the sack holder. The spreading fingers guide the sack in the movement over the sack holder so that the sack holder can take a relatively large form and the sack can fit more or less close fitting around the sack holder. This is particularly favourable when the sacks must be filled with badly "flowing" material, such as for example the previously mentioned potting compost.

[0011] An effective embodiment of this further development is obtained when the spreading fingers are connected with a ring extending round the sack holder and slidable along it and are forced towards one another with their einds by resilient means. During the movement from the pick-up position to the spread position, the fingers are as a result moved apart automatically by the sack holder.

[0012] The spreading fingers are manufactured preferably in an elastic plastic and form one whole with the ring. The ring and the fingers can be manufactured as one whole by injection moulding, while it is also possible to cast the ring in for example aluminium and injection mould the fingers onto it.

[0013] The suction nozzles used in the device according to the invention operate reliably when according to the invention each suction nozzle comprises a perforated suction face having an edge projecting from it over a short distance. The suction nozzles can hereby reliably apply on the sack the forces necessary for the required movements without releasing the sack quickly or holding it in folded position.

[0014] Further features and advantages of the invention will be made apparent in the following description of an embodiment with reference to the accompanying drawings.

[0015] 

Fig. 1 shows a schematic view of a device according to the invention for filling sacks with potting compost.

Figs. 2-5 show schematically the sack feeding device of the device in Fig. 1 in four consecutive phases of the feeding of a sack onto the sack holder.

Fig. 6 shows a partly broken away perspective view of the sack feeding device from the previous Figures.

Fig. 7 shows a suction nozzle in perspective detail view.

Fig. 8 shows the movement sequence of the spreading figers prior to, during and after passing the sack feeding device.

Fig. 9 shows in more detail a sack holder with the cooperating spreading fingers of the device according to the invention

[0016] The device in Fig. 1 comprises a conveyor device 2 which in principle consists of a circulating conveyor belt on which a number of sack holders 3 is arranged. During the circulating movement of sack holders 3 these pass a sack feeding station 4 in which is arranged a sack feeding device which arranges a sack 26 on each sack holder 3. This sack feeding station is located on the uppermost part of the conveyor belt.

[0017] Before passing sack feeding station 4 the sack holders are filled with a filling of potting compost. This compost is carried from supply hopper 9 into the sack holder using.,filling device 10. Each sack holder is provided with a piston and rod 12 slidable freely therein.

[0018] After being arranged on the sack holders the sacks move, as seen in Fig. 1, around the guide wheel on the right side after which they come to the lowest part of the conveyor belt to the actual sack filling station 6.

[0019] Above sack filling station 6 in the interior of conveyor belt 2 is arranged a rigid belt 8 which moves synchronously with conveyor belt 2. The piston rods 12 projecting upwards come into contact in filling station 6 with the underside of belt 8 and as a result of the inclined position thereof are pressed downwards during the continuing movement. The filling of potting compost is hereby pressed out of the sack holders and into the sack. Beneath the filling station is located a belt conveyor 13 which forms part of discharge station 7. Belt conveyor 13 can form a smaller angle relative to the horizontal than belt 8, so that in being pressed out of sack holders 3 the potting compost is compressed into sacks 26.

[0020] After leaving sack filling station 6 sack holders 3 are therefore empty and their pistons are situated at the bottom of the sack holders. During the movement upwards around the left guide wheel the pistons fall through their own weight back into the position shown in Fig. 1. The sack holders again pick up a new filling 11 of potting compost from filling device 10 and run through a following cycle.

[0021] The operation of the sack feeding device will now be discussed with reference to Figs. 2-5.

[0022] Sack feeding device 5 comprises two mirror symmetrical endless chains 17,18, arranged on either side of the position of a sack holder 3 in sack feeding station 4, which chains are arranged around upper chain wheels 19 and 21 respectively and lower chain wheels 20 and 22 respectively such that two chain parts are formed diverging relative to one another in the direction towards sack holder 3, i.e. in the downward direction. Chain wheels 19 and 20 are driven in the direction indicated by the arrows so that the parts of the chains 17 and 18 turned towards each other move downwards and the other parts upwards, as indicated by the arrow. Symmetrically arranged on chains 17 and 18 are respectively a first suction nozzle 27 and a second suction nozzle 28. As further shown in Fig. 6 each suction nozzle 27,28 is connected with a suction device by a coupling 40 allowing turning and a flexible hose 41.

[0023] Next to the upward moving part of chain 17 is arranged a supply holder 25 for sacks 26. In this supply holder 25 sacks 26 are supported in a row transversely on this part, such that the sack opening is directed upwards. Supply holder 25 comprises a conveyor belt which is driven intermittently in a known manner by a control device activated by a sensor, so that sacks 26 are carried to the right, corresponding to the sacks removed by the device.

[0024] Supply holder 25 is provided with a screen 29 covering the foremost sack in the row except for an end portion 32 close to the open side. When suction nozzle 27 moves upward past the foremost sack in the row, screen 29 prevents suction nozzle 27 applying suction on the foremost sack too early. Only after suction nozzle 27 has passed over screen 29.can it apply suction on end portion 32.

[0025] The first suction nozzle 27 grips the foremost sack on one side 35, doing this close to the end portion thereof, and takes this sack to sack feeding station 4r as shown in Fig. 3. In view of the self-evident and therefore unshown synchronous driving of chains 17 and 18, the second suction nozzle 28 also moves simultaneously in the direction towards the sack feeding station. As is shown in Fig. 3, a screen is arranged extending partially from supply holder 25 parallel to chain 17 around chain wheel 19, which finishes in an end edge 31 at the place where suction nozzles 27 and 28 again begin to move away from one another, i.e. at the beginning of the divergent chain parts.

[0026] As Fig. 4 shows, this achieves that, as soon as sack 26 having side 35 gripped by the first suction nozzle 27 comes out under end edge 31, the second suction nozzle 28 can likewise apply suction to the other side 36 of sack 26 and grip it in the correct manner.

[0027] With the furhter movement as shown in Fig. 4 suction nozzles 27 and 28 thus move away from one another but, in addition, move downwards, transversely to this movement away from each other, towards sack holder 3. As a result of this combined movement sack 26 is opened and moved simultaneously over fingers 16 to be described later. When suction nozzles 2.7. and 28 reach the bottom of the divergent part they are . pulled loose from sack 26 and sack holder 3 having sack 26 arranged on it on fingers 16 moves out of the sack feeding station.

[0028] Since the suction nozzles perform a continuous progressive movement this can take place at a relatively high speed without constructional drawbacks, so that sack holders 3 can likewise move continuously. It is, of course, also possible to set up chains 17 and 18 slightly inclined transversely to the plane of the Figs. 2-5, so that suction nozzles 27 and 28 in their downward movement along the divergent parts acquire in addition a motion component equal to the longitudinal motion of sack holder 3. This enables a further increase in the operating speed.

[0029] The suction device 42 shown in Fig. 6 can be formed . in appropriate manner by a vacuum aspirator. This device 42 is firmly connected with the frame of device 1 while the connection with the circulating suction nozzle 27 is made as described earlier with a flexible hose 41 and a universal joint 40.

[0030] Suction nozzle 27 comprises a perforated suction face 45 and a rim 46 projecting from it over a short distance. It has been found that with this embodiment a good grip of the suction nozzle 27 on a sack can be achieved. The height of rim 46 is in the order of magnitude of 2 mm.

[0031] In devices according to the invention where sacks must be filled with material which does not "flow" or only does so with difficulty, it is desirable that sack holder 3 has as large a section as possible. As noted earlier, potting compost is a material that "flows" with difficulty, so that .in the device shown sack holder 3 indeed has a diameter in the same order of magnitude as that of the unfolded sack. In order to ensure in such an embodiment that the sack is also placed on the sack holder in the correct way a number of spreading fingers 16 is used. In the embodiment shown spreading fingers 16 are connected with a ring 15 extending round the sack holder and slidable along it. Fingers 16 are resilient and in their unloaded state rest with the ends . against each other. In the position of ring 15 moved upwards along sack holder 3 the ends of fingers 16 can therefore converge at a point in the way shown in Fig. 9. When ring 15 rests in the moved downwards position, fingers 16 are forced apart by sack holder 3. Ring 15 is provided with projections 48 which can be gripped by a suitable guide device to move ring 15 up and downwards.

[0032] As Fig. 8 shows ring 15 is normally pushed downwards, whereby fingers 16 are spread and lie against holder 3. When a sack holder 3, moved along by conveyor device 2, approaches sack feeding station 4 the projections 48 of holder ring 15 come into contact with the upper part of a rope 49 which is driven synchronously with the movement of conveyor device 2 and runs upwards at an inclined angle. As a result of being gripped by rope 49 ring 15 is shifted upwards along holder 3 until, just before reaching sack feeding station 4, it is carried to the upper pick-up position shown in Fig. 9, in .which fingers 16 lie against one another at their ends.

[0033] After the sack holder concerned has moved through sack feeding station 4 and a sack 26 is arranged on it, projections 48 come into contact with the lower part of a rope likewise driven synchronously with conveyor device 2 which rope forces ring 15 downwards along holder 3, whereby fingers 16 are spread through contact with the wall of holder 3. In this way sack 26 is pushed further over sack holder 3, as is shown in Fig. 8.

[0034] The invention is not limited to the device shown in .the Figures. By applying modifications that are self-evident for a person skilled in the art it is possible to arrange sacks on sack holders in a direction other than downwards. The device can also take a form such that successively a sack is placed first on the sack holder and that only then the material to be put in the sack is supplied. The conveyor device for the sack holders can also take another form, such as for example a rotary conveyor device or the like.

Claims

1. Device for filling sacks comprising a frame, a number of sack holders movable by a conveyor device connected with said frame along a moving belt, whereby the moving belt extends past at least one sack feeding station close to a sack feeding device, a sack filling station and a discharge station, and whereby said sack feeding device is provided with.a supply holder accommodating sacks in folded state, a first and second suction nozzle connected to a moving device which moving device is coupled with said conveyor device for synchronous movement with the same, and which can make said first suction nozzle move between said supply holder where it can grip a sack on one side and said sack feeding station and. make said first and second suction nozzle move towards and away from one another at least close to said sack feeding station, ccharacterized in that the sack holders can support the sacks internally and the moving device is arranged in such way that it can in addition move the suction nozzles in their movement away from one another over a distance in the order of magnitude of the sack length transversely to this movement in the direction towards a sack holder present in the sack feeding station.

2. Device as claimed in claim 1, characterized in that the moving device comprises two mirror symmetrical endless flexible members, guided around guide wheels such as chains, arranged on either side of the position of a sack holder in the sack feeding station, having parts diverging relative to one another in the direction of said sack holder, that the suction nozzles are each firmly connected with one of these members and are linked by a coupling allowing rotation and a flexible hose with a suction device.

3. Device as claimed in claim 1 or 2, characterized in that the supply holder is arranged close to another part of the flexible member bearing the first suction nozzle and can support the folded sacks in a row transversely on this part.

.4. Device as claimed in claim 3, characterized in that the supply holder is provided with a screen covering the foremost sack in the row as far as a portion close to the open side.

5. Device as claimed in any of the preceding claims, characterized by a screen extending partially from the supply holder parallel to the member bearing the first suction nozzle, said screen having an end edge close to the place where the movement of the suction nozzles directed away from each other begins.

6. Device as claimed in any of the preceding claims, characterized by a number of spreading fingers which are located for movement relative to the sack holder . in the sack feeding station between a pick-up position, in which said fingers with ends moved towards one another are at an interval from the sack holder, and a spread position in which the fingers with ends remote from one another are next to the sack holder.

7. Device as claimed in claim 6, characterized in that the spreading fingers are connected with a .ring extending round the sack holder and slidable along it and are forced towards one another with their einds by resilient means.

8. Device as claimed in claim 7, characterized in that the spreading fingers are manufactured in an elastic plastic and form one whole with the ring.

9. Device as claimed in any of the preceding claims, characterized in that each suction nozzle comprises a perforated suction face having an edge projecting .from it over a short distance.

Drawing