US3009300A - Box conveying apparatus - Google Patents

Description

Nov. 21, 1961 Filed June 8, 1959 L. O. JOHANSSON BOX CONVEYING APPARATUS 4 Sheets-Sheet 1 1961 o. JOHANSSON 09,

BOX CONVEYING APPARATUS Filed June 8, 1959 4 Sheets-Sheet 2 FIG. 4. JY'F/GS. FIGS. F/G.7.

Nov. 21, 1961 o; JOHANSSON BOX CONVEYING APPARATUS 4 Sheets-Sheet 3 Filed June 8, 1959 Nov. 21, 1961 Lj O ANSSON 3,009,300

BOX CONVEYING APPARATUS Filed June 8, 1959 4 Sheets-Sheet 4 FIG. 70.

ited heats atent tic 3,009,300 BF'X CGNVEYENG AlPhARATUS Lars 0. Johansson, Tingstagatan 4t Norrkoping, Sweden Filed June 8, 1959, Ser. No. $18,912 is claims. (Ci. 53-95 It is already known, more particularly for packing into tins ground coffee and other goods which are sensitive to the influence of air, to discharge air from the tins to a gradually increasing extent and then to seal the tins in air-tight manner in a machine having a continuously rotating work table which comprises a circular row of holders which, during the revolution of the table, guide the this in succession through working stations on the circular path of travel of the holders, where the individual processing stages are automatically carried out.

The object of the invention is to permit such a vacuum machine to be used for goods to be packed in boxes or packets of cardboard or similar material, simultaneously replacing the air removed by suction from the filled packages by an inert gas.

The problem which is to be solved by the invention is concerned with the feed of the filled boxes to the box holders of the continuously rotatable table and the discharge of the boxes from the table after they have been emptied of air and filled with gas, without prejudicing the continuous revolution of the table.

The feed and discharge of the boxes to and from the rotating table is effected according to the invention in accordance with one and the same fundamental idea, namely with the help of a bridge which is provided between a feed track and the rotating table and also between the rotating table and a discharge track, the said bridges being each in the form of a guide which during the feed operation and discharge operation as appropriate moves synchronously with the table.

Instead of the tin holders, which are usually carried by the rotatable table of known vacuum machines, the table of the vacuum machine with which the present invention is concerned is equipped with a circle of box holders which each serve to receive a box. The box holders are open towards the periphery of the table, in a direction corresponding to the positions of the feed and discharge devices, so that the box holders as they pass the feed and discharge stations respectively are situated with their open sides exactly opposite the feed or discharge slide as appropriate, and the transfer of the box to or from the relevant guide can be effected by substantially rectilinear displacement.

Other objects and features of the invention will be apparent from the following description of an appropriate example of embodiment of the invention, with reference to the accompanying drawings.

In the drawings, PEGURES 1 to 7 relate to the feed device and FIGURES 8 to 13 to the discharge device.

FIGURE 1 is a plan view of the feed device. FIG- URE 2 is a side View taken on the line llll of FIG- URE 1. FIGURE 3 is a View from above of the feed device during the last feed stage. FIGURES 4 to 7 represent individual stages during the feed operation.

FIGURE 8 is a plan view of the discharge device. FlGURE 9 is a side view taken on the line IX--lX of FIGURE 8. FIGURE 10 is a side view from above of the discharge device during the first discharge stage.

FIGURES 10 to 13 illustrate a box during various stages of the discharge ope-ration.

All parts which are not absolutely necessary for the understanding of the invention have been omitted from the various figures.

In FEGURE l, the reference number ll designates three box holders of a ring of such holders provided along the 1.40! periphery of the rotating table of a per se known machine for discharging air from metal packs.

Such a vacuum machine has, projecting above the table, a tower for air-discharging and other pipes which are connected to working stations distributed along the circular path of travel along which the holders move during the rotation of the table. Since, as stated hereinbefore, the vacuum machine is known per se it is neither shown in the drawings nor described. The modification necessary in the machine owing to the invention consists merely in that the holders usually provided for receiving cylindrical tins are replaced by holders suitable for receiving cardboard boxes, said holders surrounding a box from three sides and directing an open side towards the periphery of the table. The side walls of the individual box holders do not need to be parallel to the radius extending centrally through the box holder, but are adjusted in the direction necessary for co-operation with the feed and discharge devices, as will become apparent from the following detailed description.

The feed device illustrated in FIGURE 1 consists of a straight conveying track 2. which for the sake of simplicity has been shown in the drawings as merely a fixed plane table 2 which extends from a machine (not shown) for filling boxes open at the top but otherwise closed, almost to the rotating table. The boxes in question are constructed at their upper ends with closure flaps which can be folded in a simple manner over the box end and glued fast, expediently by heat, in order to achieve an airtight seal.

The movement along the track 2 of the packs coming from the filling machine is eltccted by means of two vertically disposed endless belts 3 which each extend along one side of the track. The belts 3 are driven in a manner not shown in the drawings in the direction of the arrows by a continuously rotating shaft 4 in order to advance the packs.

Situated at the end of the track 2 is a retaining plate 5 which is provided with a contact 6. Since the retaining plate stops the movement of the packs, the belts 3 must not be tensioned more strongly than is permitted in order to allow slipping of the packs with respect to the belts owing to the resistance of the preceding packs, without damaging the packs against one another. For the same reason, it is expedient to move the packs along at some distance from one another, as indicated by the spacing a.

Fixedly mounted on the shaft 4 is an entrainment element in the form of a disc 7 having a radial shoulder 8; a

the shaft 4 also carries a rotatably mounted cam disc Whose cam is arrangedlaterally of the disc, as indicated at it). A spring-loaded brake shoe i=1 acts on the circular periphery of the disc 9. The disc 9 can be coupled to the shaft 4 by the shoulder 8 of the entrainment disc '7 coming into engagement with a ratchet pawl 12 which is spring-loaded. The pawl 12 can be removed from the path of travel of the shoulder S in opposition to the action of its loading spring 13 by means of an unlocking pin 15 which is controlled by an electromagnet 14. The circuit of the electromagnet 14 is supervised by the contact 6. If the contact 6 opens the circuit, the pin 15 is moved outwards by spring action and acts on the pawl 12 so that the latter is disengaged from the shoulder 8 or" the entrainment disc 7. The cam disc then comes to a standstill. When the circuit is again closed by the electromagnet, which happens as soon as a pack comes into Contact with the retaining plate 5 and the latter is made i By means of a cam follower element controlled by the cam 16, the cam disc 9 drives a lever 18 pivotally mounted at 17, and by means of the said lever a feed plate 19 which is movable to and fro transversely across the track 2 at the end of the said track, is actuated for the purpose of transferring the pack nearest the retraining plate 5 into a guide 20 provided at the opposite side of the track, between the latter and the rotating table of the vacuum machine, and on into a box holder 1 on the table. The guide 20 is mounted displaceably in slide 29 parallel to the track, and carries at its lower side a rotatable mounted roller 21 which, in order to move the guide in the direction of the arrow A, in accordance with the direction of rotation B of the table, is movable by means of a cam 22 which is mounted fixedly below the feed plate 19 and is in the form of a wedge tapering towards the track 2.

The cam 22 only comes into contact with the roller 21 after the pack 23 situated at the end of the track 2 just opposite the feed plate 19 has been completely transferred to the guide 29 by the action of the plate 19. The advance of the guide 29 in the direction A which is effected effected by the cam 22 is effected synchronously to the movement of the table in the direction B owing to appropriate dimensioning of the cam 10. The movement of the guide is also so regulated that the guide is situated exactly opposite a box holder 1 during the whole of the time necessary for transferring the box to the box holder. FIGURE 3 shows an intermediate position in this transfer operation.

After transfer has been completed, the feed plate 19 returns to its initial position (FIGURE 1), controlled by the lever 18 and guide 26 is returned to its initial position by diagrammatically represented spring 20", or manually.

The feed plate 19 comprises a portion 19 extending at right angles to the track 2 and an end portion 19 parallel to the track 2. By this construction feed plate 19 prevents the advance of a pack against the retaining plate 5 until the feed plate has returned to its starting position. Then the operation described hereinbefore is repeated, during which a pack in transferred into the next holder 1 of the rotating table.

The illustrated example of embodiment of the feed device is intended particularly for boxes which, at least at the end which has been used for filling the otherwise closed boxes and which is open when the boxes are delivered to the track 2, comprise end closure portions consisting of three portions which are each connected to a box side and are connected to one another at the corners, and which can be folded in a bellows-like formation over the box end, and of a separate flap which is connected to the fourth side of the box. This separate flap is used for the final sealing of the box, being folded over the three first-mentioned flaps after the latter have been folded together in a bellows-like manner over the box end. After the separate flap has been folded, it is secured in an appropriate manner in its position, for example by heating the appropriately prepared flap.

In FIGURE 7, the bellows is designated as 26 and the separate" flap is designated as 27.

Before the boxes enter a box holder of the rotating table, the bellows is pressed by means of a bellows folder 28 against the mouth of the boxsee FIGURES 2 and 5. The bellows folder is so operated by means of a cam (not shown on the cam disc 9 that it only comes into action when a pack has reached the retaining plate 5 and has influenced the latter to change-over the contact 6.

The guide 29 in addition to vertical guide walls for the pack carries a bar 29 which is fixed to the top of one of these guide walls and serves for folding over the separate end closure flap 27, before the pack enters the box holder, towards that side of the pack to which this flap is connected (FIGURE 6) so that the flap, when the box enters the box holder, can be so influenced by the ad- 4 joining side wall of the holder that it is finally pressed against the relevant side of the pack, as FIGURE 7 shows, where 1 designates the relevant wall of the box holder.

The shaft 4 with the entrainment disc 7 and the cam disc 9 is driven from the vacuum machine at a speed so regulated that one revolution of the shaft 4 corresponds to a movement of a box holder by an amount correspond ing to the spacing apart of adjacent holders in the ring of holders. If, for example, the rotating table comprises 24 box holders, the shaft 4 thus carries out 24 revolutions for each revolution of the table. The speed of the con veyor belts 5 is so calculated that, Counting from the in stant at which the feed plate 19 as returned to the starting position and at which it takes up a position of rest owing to the construction of the cam 10, a pack can be pushed forwards against the retaining plate 5 and by its impinge" ment thereagainst change-over the contact 6 in order to send an impulse to the electromagnet 14 of the holding pin 15 before the pawl 12 is influenced by the holding pin. When packs are supplied regularly to the track 2, therefore, the pawl 12 will never leave the shoulder 8 and thus the cam disc 9 in this case will rotate continuously.

As already indicated, the discharge device is biased on the same principle as the feed device.

Thus, the device of the discharge device is taken from a shaft 38 which is driven by the vacuum machine in a manner not shown in the drawings. The speed of the shaft 30 is so calculated that the shaft carries out one revolution whilst the rotatable table of the vacuum machine rotates through an angle corresponding to the spacing of two box holders from one another.

In FIGURES 8 and 10, three successive box holders 1 are indicated. Mounted fast on the shaft 30 is a cam disc 31 whose cam is indicated at 32. The direction of rotation of the shaft 30 and of the cam disc is indicated by an arrow in FIGURE 9. Cooperating with the cam 32 is a cam follower element 33 which is carried by a lever 35 mounted at 34. The lever 35 during its swinging movement controlled by the cam 32 effects reciprocation of a discharge rod 36 in a rectilinear guide arrangement. The discharge rod carries a series of entrain ment elements 37 in the form of pawls pivotally mounted at the rod, and which, from a position approximately perpendicular to the rod 36, can only be pivoted in one direc* tion, as explained hereinafter.

The discharge rod 36 extends in a horizontal plane towards the rotatable table of the vacuum machine and carries at its end facing the table a discharge arm 38 which is bent over at right angles. The direction of the discharge rod and the direction of the discharge arm are so selected that the arm can be caused by the longitudinal displacement of the rod to penetrate into the space be tween each two box holders 1 of the table and discharge a box without the rotation of the table having to be interrupted. In order to permit discharge, the box holders comprise in their end wall facing towards the center point of the table and also in their side wall facing the discharge arm appropriate apertures Whereas the opposite side wall is unbroken, see FIGURES 11-13.

The discharge rod is arranged near one side of a receiving track 39 for the packs discharged from the table, and it moves parallel to this track. Between the end of the receiving track facing the table and thetable itself a guide 40 is so mounted that it is movable to and fro in a guide which extends at right angles to the longitudinal direction of the track 39 but is not shown in the drawings. Like the slide of the feed device, the guide 40 has a pair of vertical guide walls 41 which are arranged parallel and are intended for guiding a pack transferred into the guide, and it also carries at its lower side a rotatably mounted roller 42 for effecting the advance of the slide in one direction. The roller 42 cooperates with a cam 43 fixed on the discharge rod 36. The effective cam surface is arranged obliquely with respect to the longitudinal direction of the discharge rod, in such a manner that it moves the slide towards the righth-and side of the drawings when the discharge rod moves towards the table.

The side wall of the receiving track 39 facing towards the discharge rod consists of an upper and lower bar 44 and 45 respectively (FIGURE 9) for permitting the entry of the pawls 37 into the track.

At the receiving end of the track 39 there could be provided a sealing device 46 operating with the use of heat, in order to close the bellows itself or a lining projecting from the mouth of the bellows.

During the movement of the pack by means of the rotating table from the feed station to the discharge station, the bellows part of the pack is held depressed in the position shown in FIGURES 7 and 11 by an appropriately arranged bar 47 which proceeds from the upper edge of one side wall of the box holder, whilst the separate end closure flap is held pressed against the opposite side wall. Air can therefore be sucked out of the pack and an inert gas can be introduced through the non-closed mouth of the bellows.

The removal, from the rotating table of the vacuum machine, of boxes which have been emptied or" air and filled with the appropriate goods and gas is, then, efifected in such a manner that the discharge arm 38 penetrates into the space between two box holders 1 on the table of the vacuum machine. The arm 38 remains in this position owing to the concentric form of the now effective part of the contour of the cam 32, as shown in FIGURE 9, until a box holder 1 has come into a position just opposite the guide 40. The arm 38 then begins to move outwardly and in so doing entrains the pack situated in the said box holder, and transfers the said pack to the box guide. Owing to the cam 43, the guide is capable of moving synchronously to the rotating table by spring 7 action so that the two box holders, namel the holder on the table and that constituted by the slide, remain exactly opposite one another during the transfer opera" tion. The pack is pushed from the guide on to the track 39 and takes up the position shown at 23a in FIGURE 8. The pack is now situated exactly oppositely the sealing device 4-6, if there is such a device present. During the movement of the pack into this position, the lining projecting outside the bellows is introduced by means of bars between jaws of the sealing device and is sealed. This stage is represented in FIGURE 13. In FIGURE 13, the reference numeral 26 designates the bellows, 27 designates the separate closure flap, and 5t) designates the lining which is to 'be sealed.

in the meantime, the discharge arm again moves towards the table in order to penetrate now between the box holder which has just been emptied and the succeeding box holder, and to discharge the pack from the lastmentioned holder in the sequence described hereinbefore.

The movement of the packs along the track 3% is effected by means of entrainment pawls 37 which during the movement of the discharge rod in the direction from the table carry with them the packs lying in front of them, but when the rod moves in the direction towards the table are pivoted against the rod as indicated by the direction of the arrow D in FIGURE 8. In order to prevent the packs from being moved back by the pawls 37, retaining hooks 51 are arranged at appropriate points on the track.

At suitable points on the track 3% means can also be provided for making the separate fiap 27 an outer cover I for the box end closed by the bellows.

It should be noted that during the entire discharge operation during which the box is discharged from the holder on the vacuum machine to the hot sealing device 46 the bellows of the pack is held compressed by fixed bars such as 52 (FIGURE 12) and 53 (FIGURE 13) so that a stream of gas issuing from the pack is produced for kpreventing effectively any penetration of air into the pac The means described hereinbefore can be used in conjunction with the fundamentally known vacuum machine having a continuously rotating work table inter alia for the following three kinds of packs:

(1) A pack which in the closed state contains the goods and an inert gas at atmospheric pressure. a

In this case the sealing mechanism is situated outside the vacuum machine, as indicated in the above described example of embodiment.

(2) A pack which in addition to the goods contains an inert gas at a negative pressure, which in practice means that the pack has become somewhat compressed. In this case the sealin mechanism is built into the vacuum chambers of the vacuum machine.

(3) A pack which in the closed state contains only the goods in vacuo. In this case also, the sealing of the pack takes place within the vacuum chambers.

The modifications to the otherwise known vacuum machine which are necessary for cases (2) and (3) have nothing to do with the present invention and are therefore neither described not illustrated.

I claim:

1. An apparatus for transferring filled but not closed boxes made of cardboard material to and from box holders which are arranged on a. continuously rotating work table having a driving means, of a machine for emptying the boxes of air and for introducing a gas filling, comprising in combination, a stationary bo-x transfer track, a guide arranged between said rotating tab-1e and said transfer track, said guide being mounted for movement 'to' and fro in a direction substantially tangentially to said table at a. speed corresponding to the peripheral'speed of the table, between a receiving point and a delivery point for the intert-ransfer of the boxes between table and track so that the guide can move synchronously with a box holder ofv the table and opposite the said holder for a period suflicient for the intertranst'er of a box between said guide and box holder.

' 2. A transfer apparatus according to claim 1, and in which said transfer'track extends parallel to the direction of movement of the guide, and means is provided movable to and fro transversely over the said transfer track by driving force fromsaid driving means of said rotating tab-1e for pushing into said guide the box which is foremost in said transfer track.

3. A transfer apparatus according to claim 2 and in which means is provided for synchronizing the movement of the said pushing means relative to said guide, to move the latter with the rotation of the table.

4. A transfer apparatus according to claim 3 and in which means is provided moving said pushing means to push a box from said guide into a box holder on said table.

5. A transfer apparatus according to claim 4, and in which an electric circuit is provided having an electric contact located at the end of the feed track and which is movable by the foremost box situated in the feed track, and means is provided responsive to the circuit when closed by said contact bringing into operation the driving device for said box pushing means.

6. A transfer apparatus according to claim 5, and in which means is provided controlling the transfer means driving means in dependence on the driving means for the rotating table so that the box holder on the table is situated exactly opposite the guide and is ready to receive a box therefrom as soon as the box has been finally transferred to the guide by the transfer means.

7. A transfer apparatus according to claim 1 and in which the transfer track is a discharge track arranged at right angles to the direction of movement of said guide between each two adjacent box holders of the table, to-

transfer a box from one of these holders to the guide while the guide is situated exactly opposite the said box holder and moves synchronously therewith.

8. A transfer apparatus according to claim 7, and in which the expeller is provided with means moving the guides synchronously with the movement of the table during the movement of the expeller in the direction away from the table.

9. A transfer apparatus according to claim 7, and in which said expeller means is provided with entrainment and drive elements for conveying the boxes along the discharge track stepwise.

10. A transfer apparatus according to claim 7, and in which the discharge track is provided with elastic retaining latches which prevent return movement of the packs being conveyed along the track by means of entrainment elements.

11. A transfer apparatus according to claim 7, and in which working stations are provided distributed along said discharge track for the various stages of closing the packs conveyed along said track.

12. Apparatus according to claim 1, more particularly for boxes side facing upwards while being conveyed through the vacuum machine is constructed with closure portions, consisting of three flaps each of which is connected to a side wall of the box and which are also connected to one another at the corners, and which can be folded in bellows-like manner over the relevant end, and a separate flap which is connected to the fourth side of the pack and which can be folded as a cover over the bellows and in which the box holder adjacent the guide between the transfer track and the rotating table and also the box holders on the table are provided with means for folding the bellows together over the box, so that only a small air outlet aperture remains open, and also are provided with means for folding the separate flap down against one of the verticaly disposed sides of the pack.

13. Apparatus according to claim 1, and in which the boxes are provided with linings in the shape of bellows and the box holders on the rotating table are provided with means for holding the bellows pressed against the upwardly facing end box.

14. Apparatus according to claim 11, and in which the boxes are provided with linings in the shape of bellows projecting therefrom and having a continuous periphery, and a hot-sealing station is provided near the side of the discharge track at the receiving end thereof, for the purpose of sealing the bellows of the box lining.

15. Apparatus according to claim 14, and in which means is provided for gradually pressing together the mouth of the bellows during the travel of the box from the rotating table towards the hot-sealing station for the purpose of maintaining a gas fiow issuing from the box and thereby preventing the entry of outside air.

References Cited in the file of this patent UNITED STATES PATENTS 1,998,382 Nelf Apr. 6, 1935 2,631,767 Banks Mar. 17, 1953 FOREIGN PATENTS 407,012 Great Britain Feb. 26, 1934

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