EP0395941B1 - Device for emptying bags filled with bulk material - Google Patents

Description

The invention relates to a device for emptying bags filled with bulk material according to the preamble of claim 1.

Such a device is known from GB-A-1 105 006.

In a further known device, the sack is placed through a door on a receiving table, the sack being cut into two parts by a circular knife of relatively large diameter after the door has been closed. The feed table consists of two swivel plates that form a flat surface of the feed table in their starting position. Below the swivel plates, swivel frames are arranged which are provided with spikes which pass through holes in the swivel plates before swiveling them up and penetrate into the sack such that the two separate parts of the sack are held in place when swiveling the swivel plates up. The two parts of the bag are emptied by gravity and, if necessary, by shaking the swivel plates. After the sack has been emptied, the swivel plates swivel back into their starting position, the spikes also retracting downward again from the swivel plates. The empty bag is then transported by means of a change flap to an empty bag compressor which consists of a screw conveyor arranged in a housing.

With this device, there is a risk that parts of the paper bag will be torn off and fall into the bulk material, so that the bulk material may be further processed endangered is.

In addition, the swung-up bag parts hang freely on the associated swivel plates, so that it happens that the bag parts are not completely emptied.

The invention has for its object to provide a device according to the preamble of claim 1 so that a complete and safe emptying of the sack is guaranteed, ensuring that parts of the cut sack do not get together with the bulk material in the conveyor when emptying.

To solve this problem, the characterizing features of claim 1 are used in conjunction with the preamble.

In addition, in the device according to the invention, it is possible to empty the bulk material by connecting a suction line to a collecting funnel or a screw conveyor.

In an advantageous development of the invention, the suction line has a switchover device, with the aid of which the suction process is also possible via a suction nozzle connected to the switchover device by a flexible hose. If the suction nozzle is used manually, it is possible to partially remove a defined quantity of bulk material from a sack. The emptying of the sacks using the swivel plates is interrupted while the suction nozzle is in use.

Further advantages of the invention result from the following description in conjunction with the drawing, in which an embodiment is shown schematically the device is shown.

Figur 1

die Vorrichtung in Seitenansicht,

Figur 2

die Vorrichtung in Draufsicht,

Figur 3

die Vorrichtung in einer Ansicht von hinten,

Figur 4

die Vorrichtung in derselben Ansicht, bei welcher die Fördervorrichtung für den Leersack in Arbeitsstellung gebracht ist,

Figur 5

die der Vorrichtung zugeordnete Umschalteinrichtung im Querschnitt,

Figur 6

die Umschalteinrichtung in Vorderansicht.

Show:

Figure 1

the device in side view,

Figure 2

the device in plan view,

Figure 3

the device in a view from behind,

Figure 4

the device in the same view, in which the conveying device for the empty bag is brought into the working position,

Figure 5

the switching device assigned to the device in cross section,

Figure 6

the switching device in front view.

As indicated by dash-dotted lines in the figure, the device is arranged in a housing 1. The device housing 1 has a pivoting door 2, which is also indicated in FIG. 1 in the pivoted-up position.

The device has a frame 3 which serves as a support for the various devices. Immediately behind the door 2, a stationary support table 4 is attached to the frame 3. This support table 4 is followed by a feed surface 5 on the frame, which is below the level of the support table 4.

At the end of the feed surface 5, a circular knife 6 is mounted on the frame by means of a drive shaft, which The axis is transverse to the direction of displacement of the sack. The cutting knife 6 can be rotated in the direction of the arrow by a motor drive.

The feed surface 5 adjoins at the same level, i.e. without heel, a support surface 7, which is also mounted on the frame 3.

The support surface 7 is represented by two swivel plates 8 arranged side by side, which abut one another in the horizontal position in the longitudinal center.

Below the swivel plates 8, a collecting funnel 9 is provided in the frame, to which a screw conveyor 10 is assigned.

A switching device 28, which is shown in FIGS. 5 and 6, can be connected to the conveyor screw 10.

At the free end of the support table 4, a slide bar 11 is arranged, which is supported by tabs (not shown) which engage through longitudinal slots in the feed surface 5 and are themselves guided in a longitudinally displaceable manner and can be driven by a crank drive 12. Each pivot plate 8 is pivotally mounted on a pivot axis 13, these pivot axes 13 being horizontally displaceable outwards according to the arrow directions in FIG. 3. Above the butt joint between the two swivel plates, an abutment plate 14 is fixed in place by means of a column 15 in the manner of a flag, the lower edge of the abutment plate being at a distance from the support surface 7 which is greater than the thickness of the filled sack 16.

Below each swivel plate 8 is a swivel frame 17, which can be swiveled up in the same sense as the associated swivel plate 8. (Figure 3). Each swivel frame carries spikes 26 which can pass through holes in each swivel plate 8.

A worm housing 18 is mounted on the side of the frame, the main axis of which runs parallel to the direction of displacement of the bag 16. A screw conveyor (not shown) is arranged in the screw housing 18.

The worm housing 18 has a slot 19 on the side on the underside (FIG. 4), the length of which is greater than the width of the sack 16.

A roller brush 21 is mounted by means of a swivel frame 20. The swivel frame 20 can be swiveled about a swivel axis 22 running parallel to the longitudinal axis of the screw housing 18 from an obliquely upward position (FIG. 3) in the direction of the arrow to a position in which the roller brush rests on the surface of the swivel plates 8 (FIG. 4).

The roller brush 21 is driven by a motor (not shown) in the direction of the arrow according to FIG. 3.

The worm housing 18 is provided at one end with a tubular extension 27 (FIG. 1 and FIG. 2), in front of which the screw conveyor ends.

The roller brush has plastic bristles 23, between which radially protruding metal pins 24 are attached to the roller body, which protrude somewhat from the plastic bristles 23.

In another embodiment, the roller brush 21 can be formed from a cylindrical, rotatable metal basket which has radially projecting rubber profile strips arranged on its outer circumference in the longitudinal direction of the cylinder.

In Figure 5, a switching device 28 is shown in cross section. Via a suction line 53, it can be connected directly to the screw conveyor 10 or the collecting funnel 9. The suction line 53 is connected to a suction line opening 29 of the switching device 28 with the aid of a connecting flange 31. This is formed from a cylindrical central body 44 and two disks 45 and 46 placed on the ends of the central body. The disks 45 and 46 are fixed to one another in the center by the axis of rotation 47 and screws 48 and 49. The central body 44 is arranged concentrically to the axis of rotation 47 and rotatable about this and relative to the disks 45 and 46.

The suction line opening 29 is formed eccentrically to the axis of rotation 47 in the disk 45. The connecting flange 31 and the suction line opening 29 have essentially the same diameter C. For sealing, a sealing ring 35 is arranged between the connecting flange 31 and the suction line opening 29, and the flange 31 can be connected to the disk 45 with the aid of screws 33.

A pump opening 30 is formed in the disk 46 coaxially with the suction line opening 29 of the disk 45. The diameter B of this opening corresponds to the diameter C of the suction line opening 29. Correspondingly, the pump opening is a connection 55 to a suction pump by means of a flange 32, a sealing ring 36 and Screws 34 made.

A linear channel 37 is formed in the central body 44 eccentrically to the axis of rotation 47. This channel runs at a distance F parallel to the axis of rotation 47 and, in the rotational state of the central body 44 shown in FIG. 5, connects the suction line opening 29 to the pump opening 30. The diameter A of the linear channel 37 corresponds to the diameters B and C of the disks 45 and 46 arranged openings 29 and 30. Therefore, the linear channel 37 in FIG. 5 is arranged in a form-fitting manner with respect to the suction line opening 29 and pump opening 30.

In the central body 44, a connecting channel 42 extending in the direction of the axis of rotation 47 is formed centrally between the disks 45 and 46 in its circumference 56. This is followed radially outward by a connecting flange 39 arranged in a recess in the central body. This is connected to the central body 44 with the aid of a sealing ring 40 and screws 41. A hose 54 is connected to the connecting flange and has a suction nozzle at its other end, not shown. Connected to the connection channel 32 is a pump connection channel 43 which runs parallel to the axis of rotation 47 at a distance T and continues the connection channel 42 at right angles. This has a diameter D which corresponds to the diameters B of the pump opening 30. The pump connection channel 43 passes through the central body 44 up to the disk 46. The distances E and F from the pump connection channel 43 and the linear channel 37 are of the same size, so that when the central body 44 rotates about the axis of rotation 47, the pump connection channel 43 can be rotated in a form-fitting manner with respect to the pump opening 30.

FIG. 6 shows a top view of the switching device 28 from the side opposite the bag emptying device.

In this illustration, the axis of rotation is fastened on the disk 46 by means of the screw 49. The pump opening 30 is arranged parallel to the screw 49. To connect a connection to the pump, the pump opening 30 is continued by a connecting flange 32 connected to the disk 46 with screws 34.

The connecting flange 39 surrounding the opening 38 is at least partially visible on the circumference of the disk 46. Corresponding to the connecting flange 32 of the pump opening 30, this is connected to the central body 44 with a number of screws 41, see also FIG. 5. In the direction of the center of the disk 46 formed by the screw 49, the opening 38 is continued through the connecting channel 42. This is followed by the pump connection channel 43 at right angles in the direction of the disk 46.

The representation of the switching device 28 according to FIG. 5 corresponds to a section along the line V-V in FIG. 6. In the representation according to FIG. 6, the pump connection opening 43 and pump opening 30 are arranged rotated by 90 ° with respect to the screw 49. When the central body is rotated in the direction 50 by 90 °, the pump connection opening 43 and pump opening 30 are connected to one another in alignment.

At two points on the circumference of the disk 46, two stops 51 and 52, which are arranged symmetrically to the vertical axis 57 and are designed as screws, are visible on the central body 44 (not visible in this drawing).

The operation of this device is described below.

After opening the housing door 2, the operator places a sack 16 filled with bulk material on the support table 4 in such a way that the sack lies transversely with respect to the direction of displacement.

Then the operator moves this sack over the support table 4 so that the sack slides onto the feed surface 5 and comes to rest there.

Subsequently, the cutting knife 6 is set in rotation in the direction of the arrow according to FIG. 1 and the slide bar 11 is set in motion by means of the crank mechanism 12, so that the slide bar 11 lies on the sack lying in front of it on the feed surface and in the direction of the arrow to its end position moves on the swivel plates 8. This is possible because a vertical slot is made in the slide bar, which allows the bar 11 to be slid over the cutting knife 6.

The cutting knife 6 is designed such that the apex of the cutting knife lies lower than the top 25 of the sack. The sack is thus cut open on the underside and the transverse sides, but the upper side is not cut.

As soon as the sack 16 has reached its end position on the swivel plates 8 (FIGS. 1 and 2), the swivel frames 17, which are located below the swivel plates 8, are swiveled towards the underside thereof, the spikes 26 fastened to the swivel frame 17 through the holes step into the swivel plates 8 and into the filled sack penetration.

Subsequently, the swivel frame 17 together with the swivel plates 8 are swiveled upwards in the direction of the arrow according to FIG. 3, the swivel axes 13 being moved horizontally outwards in the direction of the arrow, as indicated in FIG.

When the swivel frame 17 and the swivel plates 8 assume their vertical position (FIG. 3), each sack part is held by the spikes 26 and also pressed by the associated swivel plate 8 against the abutment plate 14 and each sack part is inevitably emptied by this compression. The uncut upper side 25 of the sack lies around the lower edge of the abutment plate 14, so that the sack parts are fully opened at the bottom, because the transverse sides of the sack are also cut open, so that the bulk material falls into the collecting funnel 9 as a result of gravity, as by the arrows indicated in Figure 3. The bulk material is then conveyed on by the screw conveyor 10.

After the bag parts have been emptied, the swivel plates 8 first swivel back together with the swivel frame 17 into their starting position, as indicated in FIG. When the swivel plates 8 have assumed their horizontal position, the swivel frame 17 swings down so far that the spikes withdraw from the holes in the swivel plate and the top of the swivel plates form a smooth surface.

The emptied sack then lies in the stretched position on the surface of the swivel plates 8, as shown in FIG. 4. After the sack usually comes out of one If the paper is relatively stiff, the empty sack does not collapse completely, but also has a certain height when empty.

Now the roller brush 21 is rotated in the direction of the arrow according to FIG. 3 and the swivel frame 20 is pivoted downwards until the roller brush 21 is pressed onto the end of the empty sack, as shown in FIG. 4. The empty sack is not only pressed flat together by the roller brush 21, but is conveyed in this flat state towards the screw housing 18, where the flattened sack enters the screw housing through the relatively narrow slot 19 and is gripped by the rotating screw conveyor and im Housing is conveyed in the same longitudinal direction.

The bag then gets stuck in the extension 27 of the screw housing 18 and is pressed together by the subsequent empty bags due to its friction on the wall of the extension. This effect can be reinforced by the fact that the extension tapers conically.

Because the sack is not cut into two parts, but is only cut open so that the two sack parts are still connected, the risk is avoided that parts of the sack material come loose and get into the funnel together with the bulk material.

Even when emptying the bag parts, this danger does not exist because the bag parts are pressed against the abutment plate 14 with considerable force until they are completely emptied.

Through the use of the roller brush as a conveyor for the empty bag, the empty bag is flattened so that the slot 19 in the screw housing 18 only has to have a very small height, so that the housing 18 made of sheet metal is practically not weakened and consequently during the conveyance of the empty bag cannot be deformed by the screw conveyor, so that the conveying action of the screw is guaranteed to be constant.

The spikes 24 provided on the roller brush capture the empty sack without delay, which would result if only the plastic bristles 23 were to act on the empty sack.

In addition, the plastic bristles are protected against excessive wear in this way because sliding of the plastic bristles over the empty paper bag is largely avoided.

The entire workflow in the device can be fully automated. This is possible in a simple manner by means of subsequent circuits. When the full sack 16 lies on the feed surface 5, the door 2 is closed. This closing process switches on the drive for the knife and sets the slide bar 11 in motion. When the slide bar 11 has reached its front end position, the swivel drive for the swivel frame 17 and the swivel plates 8 is started. At the same time, a dedusting device can be switched on.

When the swivel plates 8 have reached their pressure position for emptying the sack, the push bar 11 can be moved in again by actuating the crank mechanism 12 its starting position are retracted, furthermore, after a certain shaking movement, each swivel plate and the associated swivel frame are swiveled back into the starting position, a certain time being kept free for these processes by a time relay.

When the swivel plates have reached their starting position, the drive of the roller brush 21 and the drive for swiveling the swivel frame 20 downward are actuated until the roller brush is pressed onto the empty bag. Then the bag can be removed via a time relay, after which the swivel drive for the roller brush is actuated again and the swivel frame swivels upwards and at the same time the drive of the roller brush is stopped.

The screw conveyor can run through the entire process.

Of course, it is also possible to feed the bags to the feed surface 5 by machine.

With the help of the switching device 28, the transport of the bulk material is supported by suction. Both the collecting funnel 3 and the screw conveyor 10 can be connected to a suction pump via a suction line 53 with the aid of the switching device 28.

In a first position of the switching device 28, the suction line and the suction pump are connected to one another by a linear channel 37 and the bulk material is sucked out of the bag emptying device.

If a precisely defined quantity of bulk material is to be sucked off with the aid of the pump, it is possible to remove this defined amount manually from a sack in a second position of the switching device 28 with the aid of a suction nozzle connected to a hose. It is possible to switch between the first and second position of the switching device 28 by pulling on the hose connected to the switching device. The rotatable central region 44 is thus pivoted through an angle of 90 ° and the hose and thus the suction nozzle are connected to the pump via the connecting duct 42 and pump connecting duct 43. At the same time, the sack emptying device is automatically activated by means of stops arranged radially on the circumference, e.g. via a position indicator, switched off. In other words, as long as bulk material is manually extracted from a sack using the hose, no further sacks are emptied using the swivel plates 8.

After a defined quantity has been manually removed from the sack in this way, the central body 44 of the switching device 28 is rotated back into its other position. The hose is no longer connected to the pump and by turning the stops, the position indicator restarts the bag emptying device, swivel plates, knives, etc. Through the linear channel, which is now aligned again with the pump opening 30 and the suction line opening 29, the sacks brought up by the push-over bar 11 are emptied again with the aid of the conveying screw 10 or collecting funnel 3.

Claims (13)

1. Apparatus for emptying sacks (16) filled with bulk material, consisting of a feed device (12) conveying the sack (16) in the apparatus, a cutting device in the form of a circular cutter (6) which is disposed vertically in the region of a feed surface (5) and the apex of which is situated below the upper face (25) of the sack (16), and also of an emptying device and a collecting hopper (9) for the bulk material, characterised in that a charging table (7) adjoins the feed surface (5) in the direction in which the sack (16) is conveyed, the path of the feed device (12) extending into the region of the charging table (7), which is in the form of an emptying device consisting of two swivelling plates (8) which are upwardly swivellable towards one another out of the horizontal position and which are provided with prongs (26) which extend out of the swivelling plates (8) and penetrate into the sack parts when said plates are swivelled upwards, while between the upwardly swivelled swivelling plates (8) an upright abutment plate (14), which separately supports each sack part swivelled upwards, is disposed at a vertical distance above the surface of the charging table in such a manner that the uncut upper face (25) of the sack (16) takes up position around the bottom edge of the abutment plate (14) when the sack parts have been swivelled upwards.
2. Apparatus according to Claim 1, provided with a conveyor device transporting the cut, empty sack to an empty sack compactor, characterised in that the conveyor device consists of a rotatable roller brush (21) mounted on a swivelling frame (20) which, when swivelled downwards, presses the roller brush (21) onto the sack spread out on the two swivelling plates (8), which have been swivelled back to the horizontal position, and in that, viewed in the conveying direction of the roller brush (21), an empty sack compactor in the form of a conveyor worm mounted in a casing (18) is disposed downstream of said roller brush, said casing (18) having at the side an inlet slot (19) for the empty sack pressed flat by the roller brush (21).
3. Apparatus according to Claim 1, characterised in that each of the swivelling plates (18) of the emptying device has a swivel axis (13) which at the commencement of the swivelling operation is moved outwards by means of the swivelling device.
4. Apparatus according to either of Claims 1 and 2, characterised in that the feed device has a slip-over beam (11) provided with a slot for the passage of the circular cutter (6) while the sack is being pushed onto the swivelling plates (8).
5. Apparatus according to Claim 2, characterised in that the roller brush (21) is provided with bristles (23) of plastics material and, therebetween, with some metal spikes (24).
6. Apparatus according to Claim 2, characterised in that the roller brush (21) has a cylindrical metal basket, on the outer periphery of which are disposed elastic sectional members extending in the lengthwise direction of the metal basket.
7. Apparatus according to at least one of the preceding claims, in which a suction pipe connected to the collecting hopper is provided to carry away the bulk material, characterised in that the suction pipe (53) is connected to an opening (29) of a change-over device (28) having at least three openings (29, 30, 38), and the remaining two openings (30, 38) are connected to a pump (55) and to a hose (54) respectively, the change-over device (28) having a central body (44) which is rotatable at least in relation to the suction pipe opening (29) and the pump opening (30) and in which passages (37, 42, 43) are formed to connect the pump opening (30) either to the suction pipe opening (29) or to the hose opening (38).
8. Apparatus according to Claim 7, characterised in that the central body (44) is substantially cylindrical in shape and is mounted for rotation, relative to an axis of rotation (47) disposed concentrically to its longitudinal axis, between two coaxial discs (45, 46).
9. Apparatus according to Claim 7 or 8, characterised in that the pump opening (30) and suction pipe opening (29) are formed coaxially and with the same cross-section in respective discs (46, 45) eccentrically to the axis of rotation (47) and the connection between them can be made by a linear passage (37) formed with the same cross-section in the central body (44).
10. Apparatus according to one of Claims 7 to 9, characterised in that the hose opening (38) is formed on the periphery of the central body (44) and is continued into the central body (44) by a radially extending connection passage (42) connected to a pump connection passage (43) which extends eccentrically to the axis of rotation (47) and which extends, with the same cross-section as the linear passage (37) and at the same distance as the latter from the axis of rotation (47).
11. Apparatus according to one of Claims 7 to 10, characterised in that the linear passage (37) and the pump connection passage (43) are disposed at an angle of 90° relative to the axis of rotation (47).
12. Apparatus according to one of Claims 7 to 11, char-acterised in that in order to determine the two suction positions two radially projecting stops (51, 52) are disposed on the periphery (56) of the central body (44).
13. Apparatus according to at least one of Claims 7 to 12, characterised in that at least one stop (51, 52) is connected to a check-back position indicator device.

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