Apparatus for filling and sealing a sack with sealing member

Description

[0001] The invention relates to an apparatus for filling powder materials into a sack, comprising a material supply pipe adapted for insertion into an aperture of a sealing member of the sack and provided with means for sealing the sack and a sack supporting member pivotably mounted at the lower part of the apparatus as disclosed in AT-B 224 540.

[0002] Using this known apparatus for filling powder materials into a sack, the supply pipe tends to stick with the sealing member of the sack when activating the means for sealing the sack due to the fact that the supply pipe is in contact with the sealing member of the sack when the sealing member is closed by thermal shrinkage.

[0003] Accordingly it is the object of the present invention to efficiently seal the sack after it has been filled without the possibility of sticking the sealing member with the supply tube.

[0004] According to the invention, this object is achieved by the supply pipe comprising a nozzle detachably mounted to and projecting from the front end of the head of the pipe; said nozzle includes fine holes for supplying an adhesive or adhesive-activating to the sealing member to provide active adhesive on the sealing member for sealing the sack, detecting means for detecting the inclination of the sack and activating a first switch initiating the issue of adhesive or fluid from the nozzle when the sack being supported by the supporting member is inclined to a predetermined angle at which angle the sealing member is out of contact with the supply pipe and activating a second switch initiating pivotting of the supporting member into a horizontal supporting position when the sack is vertical and the supply pipe is inserted in the aperture of the sealing member.

[0005] Sealing sacks by injecting a fluid into the sealing member of the sack is per se already disclosed in GB-A-2 046 696.

[0006] In accordance with one feature of the invention, said detecting means comprise at least one angled lever pivotably mounted at the frame of the apparatus, one arm of which is inclined relative to the frame depending on the inclination of a sack, whereby the other arm operates the switches.

[0007] In accordance with another feature of the invention the first switch is adjustably mounted by an adjuster.

[0008] In accordance with another feature of the invention, the second switch is placed opposite to the first switch and activated by the other arm of the level to start the filling of the sack.

[0009] Other features and advantages of the present invention will become apparent from a consideration of the following detailed description and from the accompanying drawings.

Figures 1 and 2 show front views of different types of sacks used with the apparatus according to the invention;

Figure 3 shows an enlarged perspective view of a part of Figure 1;

Figure 4 shows a longitudinal sectional view of a supply pipe;

Figure 5 shows a perspective view of Figure 4;

Figure 6 shows a side view of a packing apparatus to which the supply pipe is attached;

Figure 7 shows a front view of Figure 6; and

Figures 8 to 10 respectively show a side view of the packing apparatus and its operation in the course of time.

[0010] Referring to Figures 1 and 2 which show respectively different types of sacks into which powder materials are supplied; the first sack 2 shown in Figure 1 is closed at both the upper and lower ends 11, 12 by means of sewing and is comprised of treble kraft forming a gore in both sides of the sack, while the second sack 2' shown in Figure 2 is closed at both the upper and lower ends 11', 12' by means of pasting, and is comprised of treble kraft forming a gore in both the ends. A sealing member 1, 1' is provided at an appropriate position of the sack 2, 2' respectively. The sealing member 1, 1' comprises an aperture through which a supply pipe 3 (shown in Figures 4 and 5) is inserted into the sack. The inner walls of the dealing member opposite each other, include a dried layer which is previously formed by spreading and dying an adhesive agent thereon. The adhesive agent applied to the layer is such a kind as is immediately activated to give adhesion to the layer when an activator (for example water or a certain kind of solvent adaptable to the adhesive agent) is supplied. Thus it is desirable, particularly to kraft, to use an adhesive agent substantially comprised of natural macromolecules for example polyvinyl alcohol or polyvinyl ether, because such an adhesive agent can easily be activated to be dampened again. It is also desirable to choose such a kind of adhesive agent that takes a certain time until the agent becomes sticky, during which the supply pipe 3 is released from the sack, and is not affected by an environmental temperatures. In such a manner, an adaptable adhesive agent is chosen and is spread on the inner walls of the sealing member, and then dried. If it is difficult to form the layer on the walls already made up, the layer can be formed in another way: by previously spreading and drying a chosen adhesive agent on a surface of a strip 5, for example of kraft; holding the strip so that the layer is faced together; and pasting the held strip to the inner walls adjacent to the aperture so that the layer is faced together. In this case, the held ends of the strip 5 are sewn together with the end 11 of the sack.

[0011] Though the above description applies to the case that the sack is made of kraft, if the sack is made of canvas, polystyrene is infiltrated to a part of the sack adjacent to the aperture to form the sealing member.

[0012] A sack can be easily sealed off after powder materials are supplied therein, and when the sack is made of kraft, by jetting an adapted activator (for example water or a certain kind of solvent adapted to the layer formed on the inner walls of the sealing member) to the inner walls of the sealing member, or, when the sack is made of canvas, by jetting an adapted activator (for example toluene or xylene).

[0013] Thus, the sack does not require that an adhesive agent be directly jetted from slits or fine holes provided on the cylindrical surface of the supply pipe, but does require that an adapted activator such as water or a certain kind of solvent is jetted therefrom. The advantageous features of the invention will be easily understood by a person skilled in this field. In practical use, the inconvenient problem of bunging at the slits or fine hole of the supply pipe is largely improved, and thus maintenance and efficiency of a packing apparatus is considerably enhanced.

[0014] Referring to Figures 4 and 5, which show respectively a construction and an external view of the supply pipe 3, the pipe is fixed to a frame 10 of a packing apparatus by means of a flange 6. The pipe 3 comprises a curved head adapted for insertion into an aperture of the sealing member, and the lower part of the head comprises a port 13 adapted to discharge powder materials. The rear end of the pipe 3 is connected to a conveying pipe (not shown), which is further connected to a hopper (not shown), and through which powder materials are conveyed. Thus powder materials stocked in the hopper can be brought to the supply pipe 3 by, and together with, compressed air. An expansible tube 4 is mounted on the body part of the pipe 3, both ends of the tube 4 respectively are firmly fastened to the body part. An air pipe A is provided to the pipe 3 so as to supply compressed air between the tube 4 and the outer surface of the body of the pipe, thus the tube 4 is expanded by the compressed air supplied through the air pipeA, then, when the supply pipe 3 is inserted in the sack, the tube 4 can be firmly contacted with the adjacent part of the aperture and stretches it. Thus, the tube 4 can support the sack itself in collaboration with the supporter 30 (shown in Figures 6 to 10) provided at the lower part of the packing apparatus, and the tube 4 also serves as a shutting member that closes the space between the supply pipe 3 and the aperture of the sealing member, to prevent the supplied powder materials from discharging out of the sack through the space. A discharge pipe B is provided within the supply pipe 3 so as to extend to the port 13 at the one end thereof, and the other end of the pipe B is connected, via a filter (not shown), to a circuit (not shown) which is open to the air, whereby the compressed air supplied into the sack can be discharged through the discharge pipe B when powder materials are supplied into the sack. An activator pipe W is also provided within the pipe 3 extending longitudinally to project from the front end of the head, and a jet nozzle 21 is detachably mounted to the front end of the pipe W by a screw. The other end of the pipe W is connected, via a solenoid valve (not shown), to an airtight tank in which an activator (for example water or ethanol) is stocked under compression. Thus, the activator can be supplied, under compression, to the nozzle 21 by controlling the solenoid valve with a micro-switch 25 and a timer, the operations of which will be described hereafter in detail. The nozzle 21 comprises fine holes (for example of four to six) provided on the cylindrical surface thereof, through which the activator is radially jetted in spray when the activator is supplied through the pipe W. Thus, the spread and the dried adhesive agent of the layer formed on the inner surface of the sealing member is activated by receiving the jetted spray of the activator.

[0015] Referring to Figures 6 to 10, the packing apparatus comprises, as mentioned above, a frame 10 to which the supply pipe 3 is fixed by means of the flange 6, and the apparatus further comprises a pair of bent levers 22 which are pivotably mounted to the respective side of the apparatus by an axle 20. Both the levers 22 are interconnected, at the top ends of the longer arm thereof, by a rod 23 which extends laterally relative to the apparatus. A shorter arm of either one of the levers 22 is designed so as to contact alternatively with micro-switches 24, 25 at the lower or the upper position of the shorter arm. As can be seen from Figure 6, the levers 22 are pivotably mounted on the frame 10 so that a clockwise moment acts on the axle 20 due to the weight of the levers 22 and of the centroid thereof, as far as external force is not given thereto. The apparatus further comprises a supporting member 30, which is pivotably mounted by an axle 26 to the frame 10. The axle 26 is connected, via a linkage (not shown), to an operation rod of an air cylinder (not shown). The supporting member 30 is pivotably mounted at the lower part of the apparatus so as to be kept horizontal, when the operation rod is pushed forward, and so as to be kept inclined forward, when it is drawn back.

[0016] When the pipe 3 is inserted through the aperture of the sealing member into the sack after a gore 27 of the sack has been expanded by a sucking member 8 of a handling mechanism (not shown), as shown in Figure 3, the rod 23 is pressed backward by the gore 27, whereby the shorter arm of either one of the levers 22 is contacted with the micro-switch 24, to close the switch. Then, the compressed air is supplied, through the air pipe A, in response to the operation-of the switch 24, whereby the expansible tube 4 is expanded, and simultaneously the compressed air is also supplied to the air cylinder, whereby the operation rod is pushed forward. Thus, as mentioned above, the sack is supported by both the expanded tube 4, at the aperture of the sealing member, and the supporting member 30 which is kept horizontal, at the bottom of the sack (Figures 8).

[0017] After these operations, the powder materials stocked in the hopper are supplied, through the supply pipe 3, by and together with the compressed air, into the sack. The compressed air supplied in the sack is discharged through the discharge pipe B, and the powder materials contained in the discharged air are filtrated by the filter. The powder materials supplied in the sack is automatically measured by a measuring mechanism (not shown) connected to the frame 10, and, when the supplied powder materials amount to a predetermined weight, the supply of the powder materials is stopped, and then the expanded sack is deflated by discharging the air supplied in the sack. Then, the operation rod of the air cylinder is drawn back by exchanging the supply circuit of the compressed air, whereby the supporting member 30 is inclined forward. Thus, the sack containing a predetermined amount of powder materials drops down one to its own weight (Figures 9 and 10). When the sackfalls, the bent levers 22 are pivoted following the movement of the sack. Since the microswitch 25 is designed so as to be contacted to be closed by the shorter arm of the lever 22 when the nozzle 21 comes just within the inner walls of the sealing member while the sack is inclined to fall, the switch 25 is closed when the sack is inclined to a predetermined angle, which can be seen from Figure 9. After the switch 25 is closed, both the solenoid valve, provided in a predetermined position of a circuit connected to the activator pipe W, and the timer connected to the solenoid valve are operated to supply an activator to the activator pipe Wfor a predetermined period (for example for 0.1 to 0.3 seconds). Thus the activator is jetted in spray, from the nozzle 21 to the inner walls of the sealing member, while the nozzle 21 is within the inner walls of the sealing member. The inner walls of the sealing member, on which an adapted adhesive agent has been previously spread and dried, is dampened by the activator, thus providing adhesion.

[0018] As can be easily understood,the starting point of jetting the activator from the nozzle 21 is set at the time when the nozzle comes inside the sealing member. Thus, the starting point is chosen by controlling an adjuster 28 so that the shorter arm of the lever 22 is contacted with the micro-switch 25 just when the shorter arm has been stopped by the adjuster 28. On the other hand, the end point of jetting the activator is set at the time when the nozzle 2T is released from the inside of the sealing member. That is, jetting the activator is continued until the nozzle 21 is released from the sack. Thus, the period during which the jetting of the activator is continued is determined by setting the timer according to previous tests.

[0019] The sack containing the powder materials, as shown in Figure 10, is inclined according to the inclination of the supporting member 30, and falls due to its own weight, for example onto a belt conveyor.

[0020] Since the sealing member provided for the sack is designed such that the opposite walls of the sealing member are pressed together by outward force of the powder materials supplied in the sack, the sack can be sealed while falling.

[0021] Going back to the operation of supplying the powder materials: although the nozzle 21 is ordinarily exposed to the powder materials supplied from the port of the supply pipe 3, not an adhesive agent itself but an activator is jetted from the holes arranged on the cylindrical surface of the nozzle 21, whereby bunging at the holes can be prevented. Especially if the powder material is flour, it is desirable to use ethanol as an activator since flour is not compatible with ethanol.

[0022] In such a manner, it is desirable to choose an adhesive agent which is previously spread and dried on the innerwalls of the sealing member and an activator which is applied to the dried adhesive agent, depending on the kind of powder materials to be packed.

[0023] In the above mentioned embodiments, the supply pipe 3 is used in combination with a sack. However, the supply pipe is applicable to any conventional type of sack which requires an adhesive agent to be directly jetted from the holes of the nozzle 21. In case of application to a conventional type of sack an adhesive agent itself instead of an activator is designed so as to be jetted from the nozzle 21, under greater compression compared to the foregoing embodiments due to greater viscosity. Even if the undesirable bunging occurs, which is inevitably apt to happen in practical use, the cleaning or maintenance of the supply pipe 3 can be easily performed in the apparatus according to the invention simply by replacing the bunged nozzle by another.

[0024] Though it has been well-known that the sealing member is sealed by means of a heat-melting adhesive agent, the present invention is also applicable to such a heat-melting method. In case of application to such a method, the heat-melting adhesive is previously spread and dried on the innerwalls of the sealing member of the sack, and, on the other hand, an activator adapted to the adhesive agent is designed so as to be jetted from the nozzle 21. Further, a pair of heat plates is provided at an appropriate position of a conveyor belt on to which the fallen sack is received, whereby packing can be performed in the same manner as the foregoing embodiments.

Claims

1. An apparatus for filling powder materials into a sack (2) comprising a material supply pipe (3) adapted for insertion into an aperture of a sealing member (1) of the sack (2) and provided with means for sealing the sack (2) and a sack supporting member (30) pivotably mounted at the lower part of the apparatus characterised by

- the supply pipe (3) comprising a nozzle (21) detachably mounted to and projecting from the front end of the head of the pipe (3); said nozzle (21) includes fine holes for supplying an adhesive or adhesive-activating to the sealing member (1) to provide active adhesive on the sealing member (1) for sealing the sack (2),

- detecting means (22, 24, 25) for detecting the inclination of the sack and activating a first switch (25) initiating the issue of adhesive or fluid from the nozzle when the sack (2) being supported by the supporting member (30) is inclined to a predetermined angle at which angle the sealing member (1) is out of contact with the supply pipe (3) and activating a second switch (24) initiating pivotting of the supporting member (30) into a horizontal supporting position when the sack (2) is vertical and the supply pipe (3) is inserted in the aperture of the sealing member (1).

2. An apparatus according to claim 1, characterized in that said detecting means (22, 24, 25) comprises at least one angled lever (22) pivotably mounted at the frame of the apparatus, one arm of which is inclined relative to the frame depending on the inclination of a sack (2) whereby the other arm operates the switches (24, 25).

3. An apparatus according to claim 2, characterized in that the first switch (25) is adjustably mounted by an adjuster (27).

4. An apparatus according to claim 2 or 3, characterized in that the second switch (24) is placed opposite to the first switch (25) and activated by the other arm of the lever (22) to start the filling of the sack (2).

Ansprüche

1. Vorrichtung zum Einfüllen eines pulverigen Guts in einen Sack (2), mit einem zum Einsetzen in eine Öffnung eines Verschlußelementes (1) des Sacks (2) eingerichteten Zufuhrrohrs und Mitteln zum Verschließen des Sacks (2) und einer Einrichtung (30) zum Stützen des Sacks, die verschwenkbar an dem unteren Teil der Vorrichtung befestigt ist, dadurch gekennzeichnet, daß

- das Zufuhrrohr (3) eine Düse (21) aufweist, die lösbar an und wegragend von der Vorderseite des Kopfes des Rohres (3) befestigt ist, wobei die Düse (21) feine Löcher zum Speisen eines Klebstoffs oder eines einen Klebstoff aktivierenden Mittels zu dem Verschlußelement (1) aufweist, um einen aktiven Klebstoff auf dem Verschlußelement (1) zu schaffen zum Verschließen des Sacks (2),

- Detektoren (22, 24, 25) zum Erkennen der Neigung des Sacks und Aktivieren eines ersten Schalters (25), der die Abgabe eine Klebstoffs oder eines Fluids von der Düse aktiviert, wenn der von der Einrichtung (30) gestützte Sack (2) auf einen vorbestimmten Winkel geneigt wird, bei dem das Verschlußelement (1) nicht in Kontakt mit dem Zufuhrrohr (3) ist und Aktivieren eines zweiten Schalters (24), der ein Verschwenken der den Sack (2) stützenden Einrichtung (30) in eine horizontale Stützposition veranlaßt, wenn der Sack (2) vertikal und das Zufuhrrohr (3) in die Öffnung des Versclußelementes (1) eingesetzt ist.

2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die Detektoren (22, 24, 25) wenigstens einen geneigten Hebel (22) aufweisen, der verschwenkbar an dem Rahmen der Vorrichtung angelenkt ist und dessen einer Arm relativ zu dem Rahmen geneigt ist in Abhängigkeit von der Neigung des Sacks (2), wobei der andere Arm die Schalter (24, 25) betätigt.

3. Vorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß der erste Schalter (25) von einer Justiereinrichtung (27) einstellbar gehalten wird.

4. Vorrichtung nach Anspruch 2 oder 3, dadurch gekennzeichnet, daß der zweite Schalter (24) dem ersten Schalter (25) gegenüberliegend angeordnet ist und von dem anderen Arm des Hebels (22) zum Starten des Füllens des Sacks aktiviert wird.

Revendications

1. Appareil pour remplir un sac (2) de matières pulvérulentes, comprenant un conduit d'alimentation en matière (3) agencé pour être introduit dans un orifice d'un élément de scellement (1) du sac (2) et muni de moyens de scellement du sac (2) et un élément supporte de sac (30) monté pivotant à la partie inférieure de l'appareil, caractérisé par les points suivants:

- le conduit d'alimentation (3) comprend un ajutage (21) monté détachable et en faisant saillie sur l'extrémité avant de la tête de conduit (3); ledit ajutage (21) comprend des petits trous pour amener un adhésif ou activant d'adhésif à l'élément de scellement (1) et le munir d'un adhésif actif pour sceller le sac (2),

- des moyens de détection (22, 24, 25) pour détecter l'inclinaison du sac et actionner un premier interrupteur (25) amorçant la sortie de l'adhésif, ou fluide, de l'ajutage quand le sac (2), supporté par l'élément support (30), est incliné d'un angle prédéterminé, sous lequel l'élément de scellement (1) est hors de contact avec le conduit d'alimentation (3), et pour actionner un second interrupteur (24) amorçant le pivotement de l'élément support (30) dans une position de support horizontale quand le sac (2) est vertical et le conduit d'alimentation est inséré dans l'orifice de l'élément de scellement (1).

2. Appareil selon la revendication 1, caractérisé par le fait que lesdits moyens de détection (22, 24,

25) comprennant au moins un levier coudé (22) monté pivotant sur le bâti de l'appareil, et dont un arbre est incliné par rapport au bâti en fonction de l'inclinaison d'un sac (2), l'autre bras actionnant alors les interrupteurs (24, 25).

3. Appareil selon la revendication 2, caractérisé par le fait que le premier interrupteur (25) est monté réglable par un moyen de réglage (27).

4. Appareil selon la revendication 2 ou 3, caractérisé par le fait que le second interrupteur (24) est placé opposé au premier interrupteur (25) et actionné par l'autre bras du levier (22) pour démarrer le remplissage du sac (2).

Drawing