US3481107A

US3481107A - Machine for wrapping a group of containers such as cans in material of foil type

Info

Publication number: US3481107A
Application number: US608528A
Authority: US
Inventors: Kjell Ingemar Andblad; Verner Valfrid Anvarn; Rune Paul Sigvard Samuelsson; Nils Einar Odebo; Erik Ernst Waldemar Wetterberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-01-24
Filing date: 1967-01-11
Publication date: 1969-12-02
Anticipated expiration: 1986-12-02
Also published as: DE1786486C3; DE1786483A1; DE1786485A1; DE1561939C3; DE1786487C3; FR1508615A; DE1786487B2; GB1117173A; DE1786484A1; DE1786486A1; DE1561939B2; FI45146B; NL6700965A; BE692939A; DE1786486B2; DE1786487A1; DE1786484B2; DE1561939A1

Description

ANDBLAD ET AL 3,48L107 Dec. 2, 1969 MACHINE FOR WRAPPING A GROUP OF CONTAINERS SUCH AS CANS IN MATERIAL OF FOIL TYPE 9 Sheets-Sheet 1 Filed Jan. 11, 1967 I N VEN TORS M/ELL INGEMAR ANDBLAD lFbfi/E PAUL S/GV/WD SAMUEL SSON ERIK ERA/57' WALDEMER WETTEEEMG Dec. 2. 1969 ANDBLAD ET AL 3,481,107

MACHINEFOR WRAPPING A GROUP OF CONTAINERS SUCH AS CANS IN MATERIAL OF FOIL TYPE Filed Jan. 11, 1967 9 Sheets-Sheet 5 I In" hmmgIk N A INVENTORS: I 2 KJELL INGEMAR ANOBLAD EU/VE PAUL s/am/eo S4MUELSSON ER/k E'e/vsr MLDEMAR'WETTERBEZG VERA/ER VALFR/D AM ARN IV/LS E/A/AR 00550 I @mw. W

Dec. 2. 1969 K. I. ANDBLAD ET AL 3,481,107 MACHINE FOR WRAPPING A GROUP OF CONTAINERS sUCH AS CANS IN MATERIAL OF FOIL TYPE Filed Jan. 11, 1967 9 Sheets-Sheet 4 er: Aim mz MM;

Dec. 2, 1969 ANDBLAD ET AL 3,481,107 MACHINE FOR WRAPPING A GROUP OF CONTAINERS SUCH AS CANS IN MATERIAL OF FOIL TYPE Filed Jan. 11, 1967 9 Sheets-Sheet 5 INVENTORS: M/ELL IA/GE'MAR ANDBLAD M P L S/GWD SAMUELSSON Em 5mm" Mme-m2 EI-75255 26 yam/12 MAM-2w A/vvAmv Abram/5Q Dec. 2, 1969 K. I. ANDBLAD ET AL 3,481,107 MACHINE FOR WRAPPING A GROUP OF CONTAINERS SUCH As CANS IN MATERIAL OF FOIL TYPE Filed Jan. 11, 1967 9 Sheets-Sheet 6 Dec. 2, 1969 K. ANDBLAD ET AL 3,481,107 MACHINE FOR WRAPPING A GROUP OF CONTAINERS SUCH AS CANS IN MATERIAL OF FOIL TYPE 9 Sheets-Sheet '7 Filed Jan. 11, 1967 I N VEN TORS: K/ELL INGEMAR ANDBL/JD RWE PAUL S/GWED SAMUEL SSON ERIK EPA/s7 MADE/WAR perm/uses vsxe/ve/e VALFE/D A/YVA/P/V N/LS E/NAE 00550 Dec. 2. 1969 K. I. ANDBLAD- ET AL 3,481,107

MACHINE FOR WRAPPING A GROUP OF CONTAINERS SUCH AS CANSIN MATERIAL OF FOIL TYPE Filed Jan. 11, 196'? 9 Sheets-Sheet 8 INVENTORS: X/ELL MEMAR wpezmia Rv/vE PAUL s/smea SAMUELSSON ERIK ms;- MLMMAR [VETTEEBEEG VERA/ER Mme/0 ANVA/PN N/LS E/A/AR opt-5o Armavsvs 1 196 9 K. I. ANDBLAD ET AL MACHINE'FOR WRAPPING A GROUP OF CONTAINERS SUCH AS cANs IN MATERIAL OF FOIL TYPE 9 Sheets-Sheet 9 Filed Jan. 11, 1967 FIG. 23

I N VEN TORS KJELL INGEMAR ANDBLAD ROWE PAUL. SIGVARD WEI. SSON ERIK ERN T WEITERBERG VERA 7? I/ALFR/D A/VWfi V A rramvEY:

United States Patent Int. Cl. B65b 11/10, 35/36, 35/54 US. Cl. 53-159 16 Claims ABSTRACT OF THE DISCLOSURE This disclosure teaches a machine for wrapping in a foil a group of containers arranged beside each other s that viewed from above each group substantially forms a rectangle. The containers are fed into the machine in a single row and are formed into groups. Thereafter a foil casing is wrapped longitudinally over and under the formed group and then the side openings are sealed.

The present invention relates to a machine for wrapping a group of containers, such as cans, which are arranged beside each other so that, viewed from above, they mainly form a rectangle, in a material of foil type, such as shrinkable foil, the containers then being fed into the machine in the form of one single row. It is previously known to assemble a number of cans or bottles or other containers so that they occupy a surface which is a module of the total surface of a loading pallet. A group thus formed is enclosed in two sheets of shrinkable foil in such a way that the group is placed on one of the sheets and the other sheet is placed on top of the group. Adjacent edges of the two foils are fastened to each other by means of welding. The wrapped group is thereafter subjected to heat, and the wrapped group forms a rigid pack. This pack can thereafter quite simply be placed on a loading pallet without any risk that the wrapping will break. A number of packs prepared in this way can thus be placed on a loading pallet, in several layers, just as if each pack had been a carton. It is an extremely simple and cheap method of wrapping and transporting containers. Hitherto, wrapping of containers in material of foil type has been carried out manually, which is extremely time-consuming and expensive, owing to high wages, but in spite of this, it is cheaper than other packing methods.

The purpose of the present invention is to create a machine that, without any manual influence, achieves the wrapping of said groups in a material of foil type. The machine according to the invention is designed for plastic 'shrinkable foil, but it should be obvious that it can also be used for foil of other materials, such as e.g. aluminium, paper and the like. The parts that will be varied are the members which join the adjacent edges of the foil together.

The present invention is characterized by a number of different units, which carry out different operations. In the present case, these units comprise the parts of a complete machine, but can also comprise independent units, which can be used in other, future machines. The units comprised in the machine are thus not limited to the present machine.

The machine according to the present invention is characterized by a dividing unit for dividing said single row of containers into two rows, of a group-forming unit for forming said groups of containers coming from said two rows, of a blocking unit to prevent the feeding of a formed group, by a foil unit containing two rolls of foil located transversely in relation to the conveyor track along which each group formed is to be fed, one of the rolls then being located over the conveyor track and the other under the conveyor track, and the free ends of the two foils then being joined to each other through a transversal opening in the conveyor track, by a conveyor unit which transports the group formed past said transversal opening, by a first welding unit for making a transversal weld joining adjacent foil surfaces at the rear end of a formed group, of a tensioning unit, which stretches adjacent foil surfaces along the sides of the group, by a second welding unit which welds the last-mentioned foil surfaces, possibly a second conveyor unit which transports said group to or adjacent to said second welding unit and possibly by a shrinking unit in which the foils are subjected to heat of such a temperature that the foils, if they consist of shrinkable plastic, are shrunk.

The present invention will be described in more detail in conjunction with the attached drawings, showing the various part units of the machine. Thus, FIG. 1 shows a side view of a dividing unit, FIG. 2 a top view of same dividing unit, FIG. 3 a side view of a group-forming unit, FIG. 4 a top view of same unit, FIG. 5 and FIG. 6 a blocking unit in two different working phases, FIGS. 7 and 8 a foil unit and a conveyor unit in two different working phases, FIGS. 9 and 10 a second conveyor unit in two different working phases, FIG. 11 a first welding unit, FIG. 12 a tensioning unit, FIG. 13 a blower device for putting adjacent edges of the foil into contact with each other, FIG. 14 a second welding unit, FIG. 15 a shrinking unit, FIG. 16 another embodiment of a group-forming unit, FIG. 17 another working phase of said group-forming unit, FIG. 18 another embodiment of the first conveyor unit, FIG. 19 a part of said conveyor unit, FIGS. 20, 21 and 22 another embodiment of the tensioning unit in different working phases, FIGS. 23, 24 and 2S dilferent working phases of a part of the tensioning unit.

FIGS. 1 to 15 show different units belonging to one and the same machine. FIG. 1 shows a conveyor track 1 for containers 2 which, in the present case, have a cylindrical form. It should be obvious that the containers can consist of bottles, glass jars and other containers of any arbitrary material. The conveyor track 1 can consist of an endless belt, and coacts with two

vertical walls

3 and 4, so that the containers are guided transversely. These two walls are usually at a distance from each other that corresponds approximately to the diameter of a container 2, and then at the part of the conveyor track which is to the left of the section shown in the figures. In these the distance is greater than the diameter of a container 2 and then preferably 1 /2 times the diameter of a container. At one side of the conveyor track a wheel 5 is arranged, which is fastened to a shaft 6, which wheel is given a rotation in the direction indicated by the arrows 7 and 8. The wheel is provided with a number of peripheral recesses 9. Each recess has a width along the periphery corresponding approximately to the diameter of a container 2 and a depth corresponding approximately to one-half of the diameter of the container. Between each recess there is a peripheral edge 10 on the wheel 5, which has a length corresponding approximately to the diameter of a container 2. Just before the wheel, to the left of same, as shown in FIG. 2, an extra wall 11 is arranged, which presses the containers 2 against the wall 3. This involves that when the conveyor belt 1 is moved in the direction indicated by the arrow 12, the containers will move towards the wheel 5, and every other container will then come into contact with the edge and every other container with the recess 9. The container which comes into contact with the edge 10 will assume a position near the wall 4, while the container which comes into contact with the recess 9 will come into contact with the wall 3, as is clearly shown in the part of FIG. 2 which is located immediately to the left of the wheel 5. A little farther to the right, the distance between the

Walls

3 and 4 is increased so that the distance between the walls will be somewhat greater than twice the diameter of a container. In the middle between the two walls a wall 13 is arranged. At the left end of the wall 13 a rotatable wheel is arranged. This wheel is rotatable around a vertical axle. As will be clearly noted from FIG. 2, every other container will be fed to the conveyor track which is limited by the

walls

4 and 13, and the intermediate containers to the conveyor track which is limited by the

walls

3 and 13. The function of the wheel 14 is to reduce the contact friction between a container and the wall 13 at its left end. The wheel could be eliminated without any major disadvantages, but it is an advantage to have it. The reason for the use of the wheel 5 is that, through the use of same, it is avoided that containers which have been fed in will become locked together at the transfer to the two different conveyor tracks, which can occur at intermittent operation of the conveyor belt 1. The containers from the two conveyor tracks are fed to a group-forming unit.

FIGS. 3 and 4 show a group-forming unit, and then only one half of such a unit. The other half functions identically, and has been left out in order to give a more clear picture. In the figure, the conveyor track formed by the

walls

3 and 13 will be noted to the left. The conveyor track emerges towards a wheel 15a which is rotatable around an axle 15. If desired, the axle can be connected to a driving member, which makes the axle turn in the direction indicated by the arrow 16. Normally, said driving is not required, owing to the fact that at the mouth of the last-mentioned channel the containers are driven out on an endless conveyor belt 17, which passes by an idler 18. The wheel 15a is provided with a number of groups of recesses, which groups are arranged after each other along the periphery of the wheel. Each group has three

different recesses

19, and 21, which are identical for each group and have different depths. The number of recesses corresponds to the number of

compartments

22, 23 and 24 to which the containers are to be fed. If more than three compartments are desired, each group of recesses in the wheel 15a will amount to a number corresponding to the number of compartments.

Through the movement of the endless belt 17 towards the right, the containers coming from the conveyor track formed by the

walls

3 and 13 are forced into

recesses

19, 20 and 21 in the wheel 15a, and are retained in said recesses during the continued rotation of the wheel, under the coaction of the wall and the movement of the conveyor belt. The

different compartments

22, 23 and 24 are formed by the

walls

26, 27, 28 and 29. Said walls extend towards the periphery of the wheel in such a way that containers located in recesses of the type which has been given the reference designation 21 go into compart ment 22, that containers located in recesses of the type which has been given the reference designation 19 go into compartment 23 and that containers located in recesses of the type which has been given the reference designation 20 go into compartment 24. This is due to the fact that the front walls in the recesses in the direction of rotation, straight against which the containers are pressed during a A to /2 turn, have such releasing angles that the containers are carried along to the compartment desired. At the mouth of the conveyor track which is formed by the

walls

3 and 13, a blocking wall is arranged, so that the containers can only be given the direction of movement which they have obtained in FIG. 4. In the present machine, it is the intention that the conveyor belt 17 should travel only such a distance that three rows of containers are collected in the

compartments

22, 23 and 24. The further movement of the first row is blocked by a plate 31, belonging to a blocking device. At the blocking plate, two thin,

rigid wires

32 and 33 are arranged. These form an extension of the

walls

27 and 28. The

walls

26 and 29, on the other hand, have a length corresponding mainly to the total length of the wall 28 and the wire 33. or the Wall 27 and the Wire 32.

The blocking device with said plate 31 and said

wires

32 and 33 is described in more detail in FIGS. 5 and 6. In FIG. 5 the blocking plate 31 is shown in its upper position, and in FIG. 6 in its lower position. Arriving containers 2 are blocked at the upper position. The distance between the top of the conveyor belt and the opposite, bottom of the blocking plate 31 is chosen so that the containers are not given any tipping movement. At the lower position the bottom of the blocking plate 31 is more or less in contact with the conveyor belt. The edge of the blocking plate 31 which faces the containers is provided with a beveled surface 34 so that the containers can pass the blocking plate 31. The

wires

32 and 33 have such a diameter that they will be in the space formed by the round sections which containers as a rule have, particularly if these are bottles or glass jars. The containers can then be placed in direct contact with each other transversely, in spite of the steering properties of the

wires

32 and 33. The blocking plate 31 coacts with a second plate 35. This is in order to achieve a connecting link between the conveyor belt 17 and a following conveyor belt 36. It is necessary to have such a bridge as there is always a space between two conveyor belts. The bridge, which is formed by the

plates

31 and 35, provides for an unhampered transfer of containers to the conveyor belt 36. The plate 35 has a bracket-like plate at each end, at right angles to the plate 35. In FIG. 5, one of said two bracket-like plates 37 is shown. Said second plate is rotatably supported on a horizontal axle 38, which is fastened to a fixed vertical wall element 39. The lowermost end of the bracket-like element is fastened to the other end of an arm 40, one end of which is fastened to a control member 41, which in the present case is of a hydraulic character, but can be of any other kind whatsoever, on the condition that the control member can make the plate 35 assume either the position shown in FIG. 5 or the position shown in FIG. 6. The control member 41 is fastened to a vertical bar 42, belonging to the blocking device. On its bottom, at each end, the plate 31 is provided with an L-formed member, as is clearly shown in FIG. 5. At its right-hand end, said L- formed member is supported on an axle 44, which is fastened to the bracket-like plate 37. At the left-hand end of the L-formed element, one end of an arm 45 is supported through an axle 46. The other end of the arm is movably supported on an axle 47 at the vertical wall element 39. It will thus be possible to raise and lower the blocking plate 31 by means of the link mechanism described. It should be obvious that any other suitable link mechanism can be used, provided that the blocking plate 31 can be moved between the positions shown in FIGS. 5 and 6. The blocking mechanism described can be used generally as a connecting member between two arbitrary conveyor belts in equipment in which two conveyor belts located one after the other are included.

For the further transport of a group of containers which has been formed in front of the blocking plate 31, a first conveyor unit is required. This is shown in its starting position in FIG. 3, together with the groupforming unit. The conveyor unit is also shown in said position in FIG. 7. In FIGS. 8 and 9 the conveyor unit is shown in its other end position. The conveyor unit is formed by the

walls

26, 27, 28 and 29, shown in FIG. 4. Said walls are fastened to each other by means of a transversal bridge-like element 48, which is provided with a vertical axle at each end, one of which, 49, is shown in FIG. 3. Each axle is joined to a feeding member, and these are located on either side of the belt 17. One of the feeding members, which is shown, has been given the reference designation 50. Each member is movable along a horizontal bar, which is parallel to the direction of movement of the conveyor belt 17. The feeding member 50 coacts with a bar 51. The conveyor unit is also provided with a carrier, which consists of a transversal part 52, provided with three

vertical tongues

53, 54 and 55. The part 52 is joined at each end with a vertical bar each, designated 56 and 57. The lower end of each bar is connected with a hydraulic cylinder, of which the one for the bar 56 is shown in FIG. 3, and in which it has been given the reference designation 58. Through said hydraulic cylinder, which is fixed to the feeding member, the carrier can be raised and lowered. In the raised position the containers can pass by, and in the lowered position the containers are pushed on by the carrier at a movement to the right of the feeding member 50. The righthand ends of each

wall

26 and 29 in the conveyor unit are each fastened to a finger, 59 and 60, which fingers are directed forwards. Each finger has its left-hand end supported on a horizontal axle, of which the one for the finger 60 is shown in FIG. 3, and where it has been given the reference designation 61. All fingers are provided with spring members not shown, so that, at their normal positions, they assume the positions shown in FIG. 3. The right-hand end of each finger is provided with a transversal part, 62 and 63, which parts are directed outwards.

The conveyor unit described functions in such a way that when the space limited by the carrier and the plate 31 has been filled with containers, the carrier is lowered from its uppermost position, as shown in FIG. 3, to the position shown in FIG. 7. Thereafter, with the aid of the feeding member 50, the conveyor unit is moved to the right, to the end position shown in FIGS. 8 and 9. Before such a movement can take place, the blocking unit must assume the functioning position shown in FIG. 6. After the conveyor unit has assumed the position shown in FIG. 8, the carrier is again raised to the position shown in FIG. 3, and the conveyor unit is thereafter moved to its starting position, after which the blocking unit assumes the functioning position shown in FIG. 3. In this position the group-forming unit can form the following group. The application of the conveyor unit is not limited to the present machine, but can have applications in any machine in which a conveyor unit of the kind described is required.

In FIG. 7 a foil unit is shown, in which a foil 64 comes from a roll of foil not shown. In the figure, also a foil 63, coming from a roll of foil located under the conveyor belt 36, is shown. The two free ends of the

foils

64 and 65 are joined to each other by means of a welding procedure, which will be described in more detail in the following. In the figures, also two guiding

members

66 and 67 for the foils are shown. In the present machine the foils are to consist of shrinkable plastic. During its movement towards the right, by means of the

fingers

59 and 60, the conveyor unit will grasp the blocking foil and move it towards the right, as is clearly shown in FIGS. 7, 8 and 9-.

The first-mentioned conveyor unit coacts with a second conveyor unit. This is shown in FIGS. 9, 10, 11 and 12. The second conveyor unit consists of two fork-

like elements

68 and 69. Each fork-like element has two parallel prongs, and the distance between the prongs corresponds to the length of a group of containers. Said forks are movable transversely, as is clearly shown in FIGS. 9 and 12. Each

fork

68 and 69 is provided with its

shaft

70 and 71, each of which coacts with its

hydraulic device

72 and 73, so that the forks are put into and out of contact with a group of containers. The

hydraulic devices

72 and 73 are each joined with a

plate

74 and 75, which plates are movable in the longitudinal direction of the conveyor belt 36.

The second conveyor unit functions in such a way that when the first conveyor unit has moved a group of containers to the position shown in FIG. 9, the forks of the second conveyor unit are moved towards said group, so

- that the second conveyor unit has a complete grip on the entire group. The moving of the forks towards the group is facilitated by said

fingers

59 and 60, as they form a space in front of the group. When the forks in the second conveyor unit have the previously mentioned grip on the group, as shown in FIG. 10, the forks are located above the

walls

26 and 29. When the first conveyor unit returns to its starting position, the

fingers

59 and 60 bend down under the prongs of the forks, owing to their being spring loaded. At said group, the two foils 64 and 65 are caused to meet at the rear of the group, and the two meeting foils are then Welded together, so that the group is enclosed in a foil tube. At the same time, the foil tube formed is cut off from the two rolls, and the separation from the two rolls along the weld then takes place in such a way that the ends from the two rolls will be joined to each other. This welding procedure, which has taken place at a first welding unit, will be described in more detail in the following. The functioning of the welding unit has already been described, in order to make it easier to understand the functioning of the machine. The second conveyor unit now moves the enclosed group along the direction of movement of the conveyor belt 36 to a position in front of a second welding station. In this position the forks move transversely outwards, as shown in FIG. 12. When this has taken place, a tensioning unit begins to function, which contains four stick-formed members 76,

77, 78 and 79. These stick-formed members, in turn, are joined to the

parts

80, 81, 82 and 83, which coact with two control devies not shown, which are arranged at the

plates

74 and 75. The stick members function in such a way that when the

forks

68 and 69 have left the group, as shown in FIG. 12, the stick-formed members are inserted in the openings formed by the foil covering around the group at its sides. The insertion takes place in such a way that the stick-formed members are inserted in the centres of the opening and are thereafter given a movement in the longitudinal direction of the group, so that the foil is stretched in the way shown in FIG. 12. The purpose of this is to facilitate a forthcoming welding in each side joint. With the aid of the movement of the belt 36 in the direction indicated by the arrow 84, the group is moved to a second welding unit, where said welding of the side joints takes place. When the welding has been completed, the stick-formed members are returned to their starting positions.

In the foregoing it has been mentioned that the second conveyor unit moves the group to a position in front of the second welding unit. However, according to another alternative, the forks can be given a retaining function only at the first welding unit. After the welding has been completed, the forks are returned, at the same time as the stick-formed members begin to function. Thereafter, both the belt 36 and the

plates

74 and 75 are given a movement towards the right, to the second welding unit.

The first welding unit is shown in FIG. 11, and consists of two

transversal parts

85 and 86, which can move vertically in any appropriate way whatsoever. When the

parts

85 and 86 move towards each other to make contact as shown in FIG. 11, the foil surfaces which are put into contact with each other by the

parts

85 and 86 are fastened together by means of heat or in some other known way, at the same time as a transversal cut is made through the weld, so that the foils coming from above and below are separated from the foil parts which enclose the group. When the

parts

85 and 86 thereafter separate from each other, the foil parts which cover the group at its rear end are fastened together, as well as the free ends of foil coming from the two rolls not shown.

During the transport from the first welding unit to the second welding unit, the longitudinal edges of the cover for the group are subjected to a jet of compressed air on each side of the conveyor belt. Each jet of compressed air comes from a nozzle. One of these nozzles is shown in FIG. 13, and has been given the reference designation 87. The function of each jet of compressed air is to move the opposite foil surfaces towards each other, i.e. they are a complement to the stick-formed members.

The second welding unit consists of two longitudinal, fixed

parts

88 and 89, which are arranged one on each side of the conveyor belt 36, and are located at a height which corresponds to the height of the foil parts which are to be fastened together. It is, of course, obvious that the height can be chosen as desired. Each

part

88 and 89 coacts with a

second part

90 and 91, which can move vertically and are in contact with the

parts

88 and 89. When a wrapped group is moved into the position shown in FIG. 14, i.e. the position where the foil surfaces which are to be fastened together thus are resting upon the

parts

88 and 89, the

parts

90 and 91 are moved into contact with the

parts

88 and 89, and welding of the opposite foil surfaces takes place in a known way, so that the group is hermetically sealed. The

parts

88, 89, 90 and 91 thus contain elements which achieve welding. After the welding has been carried out, the

parts

90 and 91 are moved away from the

parts

88 and 89, after which the conveyor belt moves the wrapped group to a shrinking unit, which is shown in FIG. 15. The shrinking unit consists of a number of

nozzles

92, 93, 94, 95 and 96, which blow air of such a temperature that the plastic foil which encloses the group shrinks in such a way that the whole of the group becomes a rigid pack and, from the point of view of handling, can be treated in the same way as a carton. In FIGS. 16 and 17, a second design of a group-forming unit is shown. As will be noted from FIG. 16, the two groups of containers from the dividing unit are fed onto two conveyor tracks which are parallel to each other, and each of which form an

endless conveyor belt

97 and 98. The two conveyor belts are on either sides of the surface 99, where a group of containers is to be formed. On the outer side of each of the

conveyor belts

97 and 98 there is a pushing member, of which only one is shown in FIGS. 16 and 17. The pushing member consists of a transversely movable pusher 100. It is fastened to one end of a shaft 101, the other end of which is a movable, pneumatic device. By means of this pneumatic device 102, the pusher 100 can be displaced between the position shown in FIG. 16 and a position which can be located near the center of the surface 99. At each end of the pusher, two

rods

103 and 104 are arranged. Each of these rods runs in the bearing

devices

105 and 106, and 107 and 108, respectively. The purpose of the

rods

103 and 104, with hearing devices, is to act so that the pushing member 100 is always parallel to the longitudinal axis of the surface 99, the longitudinal axis of which is also parallel to the feeding direction of the

conveyor belts

97 and 98. At one end of the surface 99, a pushing member 109 is arranged, and at the other end of said surface a blocking member 110 is arranged. This blocking member is most clearly shown in FIG. 18. If the last-mentioned figure is regarded again, it will be noted that, at its ends, the pusher is fixed to two bars 111 and 112. At the rear end of each bar, a vertical plate 113 and 1 14 is arranged. These two vertical bars each run in a

groove

115 and 116 in the surface 99. The two

vertical plates

113 and 114 are connected to a driving machinery not shown, preferably of a pneumatic type, so that the pusher 109 can be moved back and forth in the axial plane of the surface 99, between the position shown in FIG. 16 and the position shown in FIG. 18. The

plates

113 and 114 each coact with a

bar

117 and 118. Each bar has a cleat. This cleat can be seen at the bar 117, and has been given the reference designation 119. When the plate 113 comes into contact with the cleat 119, the bar 117 is moved in the same direction as the pusher 109. In the front end of each of the

bars

117 and 118 there is a transversely directed

finger

120 and 121, respectively, arranged, which are directed inwards. At the front end of each finger a line 122 is fastened, which runs rearwards, parallel to the bars 111 and 112. The line 122 runs on a wheel 123, which is rotatable around a vertical axle 124, and also around a vertically arranged wheel 125, which is rotatable around a horizontal axle 126. These two wheels are fixed at the side of the bar 111. A weight 127 is fastened at the free end of the line 122. A corresponding line with wheel and weight is arranged at the upper side of the conveyor track which is shown in FIG. 18. In this figure, also the two foils 64 and 65 are shown, as well as an endless belt 127, arranged as an extension of the surface 99.

The group-forming unit described in FIGS. 16, 17 and 18 functions in the following way. It is assumed, however, that only one of the pushing members is functioning, and that only one of the belts, 98, is operating. When now the belt 98 is in motion, containers 2 are fed by means of this to a position, where the foremost container is in front of the blocking member 110. When this has taken place, the pushing member starts to function, and pushes on three containers, as shown in FIG. 17. The first longitudinal row is pushed in so far that three longitudinal rows can be placed side by side on the surface 99. When the first container is in position, the pusher 100 returns to the position shown in FIG. 16, after which the belt 98 starts up, and feeds three new containers to the same position as the foregoing containers. Thereafter the pusher 100 functions anew. The last row of containers is pushed onto the surface in the same way as has just been described. The

belts

97 and 98 also operate continuously. The first row can also be pushed in so that it just comes onto the surface 99. It is then moved farther in on the surface 99 by the following rows when these are pushed in. In FIG. 18, the finished group being displaced is shown. The finished group is first in contact with the blocking unit 110, and cannot be displaced at all until the blocking device has assumed its non-blocking position. It should be obvious that a formed group can have a longitudinal row that contains more than three containers, as well as a width that exceeds three containers. When both of the pushing members and the

conveyor belts

97 and 98 are used, the group is, of course, formed more rapidly. The non-blocking position is assumed only after the pusher 109 has come into contact with the group from the rear, but said position can also be assumed before said contact. When this has taken place, the

plates

113 and 114 have also come into contact with the corresponding cleats 119, which involves that the pusher takes along the

bars

117 and 118, with their fingers and 121. The fingers move the blocking foil forwards, as is clearly shown in FIG. 18. The pusher 109 and the

fingers

120 and 121, with the devices belonging to these, form a second variant of the first conveyor unit. The conveyor unit moves the formed group to the position shown in FIG. 18. During the transport, the lines 122 Will prevent the containers from moving transversely. In the position shown in FIG. 18, the conveyor unit leaves the formed group, and the group is sealed at its rear end in a way corresponding to the way shown in FIG. 11. Thereafter the enclosed group is transferred to the second welding unit, where the group is thus to be welded along its sides. At the second welding unit there is a tensioning unit, which is of a different design than the one previously described. The tensioning unit consists of two identical parts, which are arranged on each side of the enclosed group at the second Welding unit. Each part consists of two

arms

128 and 129, which extend parallel to the longitudinal direction of the conveyor belt 127. Each arm has one end fastened to a

shaft

130 and 131, respectively. Each shaft is moreover arranged at right angles to its arm, and each is rotatably supported in a bearing

member

132 and 133. On each shaft also a wheel or, alternatively, a sprocket, 134 and 135, is fastened. A line 136 or, alternatively, a chain which has One end fastened to a spring not shown, and the other end of which is anchored, runs over the wheels or sprockets. The other end of the line 136 is fixed to a rod 137 of a hydraulic device or, alternatively, to a pneumatic device 138, which can give the line a movement. The two

shafts

130 and 131 are arranged at such a distance from each other that the free ends of the two

arms

128 and 129 can be arranged facing each other. This is the starting position of the arms. At the free end of the

arms

128 and 129 the

parts

139 and 140, respectively are arranged, which are rotatable around the

axles

141 and 142, respectively, which are parallel to the longitudinal direction of the arms. At each

part

139 and 140, a

stick

143 and 144, respectively, is arranged. Each

part

139 and 140 contains a spring 139a and 140a, respectively, which strives to turn the two

sticks

143 and 144 into a position which is parallel, and at right angles to the surface 127 of the conveyor belt. However, the

parts

139 and 140 are prevented from moving to the previously mentioned position through the influence of a blocking member 145. (See FIGS. 23 and 25.) This blocking member has a blocking action only when the free ends of the

arms

128 and 129 have the position shown in FIG. 20, which shows the starting position of the arms.

The tensioning unit described functions in the following way. When a Wrapped group is at the second welding unit and directly opposite the tensioning unit, the hydraulic member 138 is actuated in such a way that the rod 137 is drawn into the hydraulic device 138. The two

arms

128 and 129 are then given a movement upwards, to the position shown in FIG. 21. When the arms move up, the blocking member 145 loses its blocking effect, which has the consequence that the

sticks

143 and 145 are turned inwards towards the conveyor track 127, so that the sticks will be parallel to the surface of the conveyor track. The second part of the tensioning unit, located on the opposite side, functions in an identical way. The sticks at the two part units put opposite surfaces which are to be welded together at the second Welding unit into contact with each other, through streching from inside. When the welding has been completed, the arms are returned to the starting position, and the sticks then also return to their starting positions.

It should be obvious that the containers 2 in the lastmentioned embodiment can be transferred to the surface 99 in any appropriate way whatsoever. In this embodiment, the lines 12 and the

fingers

120 and 121 have been replaced by two supporting rules, which are movable transversely and parallel to the direction of movement of the belt 127. The rules have such a position along the conveyor track that, when a group of containers is wrapped in foil, the whole group is located between the supporting rules. During the wrapping procedure, the two supporting rules assume such a position transversely that the group can just barely pass through. After the wrapping has been completed, the rules move away from each other.

We claim:

1. A machine for wrapping in a foil a group of containers arranged beside each other so that viewed from above each group substantially forms a rectangle with the containers being fed into the machine in a single row along a conveyor track which has an endless belt serving as its floor and which has side walls, the machine comprising in combination:

dividing means for dividing the single row of containers into two rows,

group-forming means for forming said groups of containers coming from said two rows,

blocking means to prevent feeding of a formed group,

a foil unit including two rolls of the foil located transversely relative the conveyor track with one of the rolls located over and the other located under the conveyor track and with free ends of the two foils joined to each other through a transverse opening in the conveyor track,

first conveyor means which transports a formed group past said transverse opening,

first welding means for making a transverse weld joining adjacent foil surfaces at the :rear end of the formed group,

tensioning means which stretches adjacent foil surfaces along the sides of the formed group,

second welding means which welds the last-mentioned foil surfaces,

second conveyor means which transports the formed group to said second welding means,

the foil made of a plastic material which is shrinkable on heating,

shrinking means for subjecting the foil to heat of such a temperature that the foil is shrunk,

the dividing means comprising a distribution wheel rotatably arranged on a vertical axle and protruding partly into the conveyor track with the transverse distance between side walls on one side of the wheel from which the containers are fed toward the wheel corresponding to the width of a container and at the other side of the wheel exceeding the width of a container but less than twice the width of a container,

the distribution wheel provided along its periphery with equally spaced recesses to accommodate containers and the spacing being chosen so that every other container is carried on the conveyor track by means of a recess and alternate containers by the periphery of the distribution wheel between successive recesses,

two following conveyor tracks provided on said other side of the distribution wheel with each of said lastmentioned tracks having a width corresponding to a width of a container,

the ends of two adjacent walls of the following conveyor tracks forming a common edge at the input ends thereof.

2. The machine according to claim 1 with a vertical axle arranged at said common edge,

a second wheel rotatably arranged on said last-mentioned axle to facilitate feeding of the containers into said following conveyor tracks.

3. A machine for wrapping in a foil a group of containers arranged beside each other so that viewed from above each group substantially forms a rectangle with the containers being fed into the machine in a single row along a conveyor track which has an endless belt serving as its floor and which has side walls, the machine comprising in combination:

dividing means for dividing the single row of containers into a plurality of rows,

group-forming means for forming said groups of containers coming from said rows,

blocking means to prevent feeding of a formed group,

first welding means for making a transverse weld joining adjacent foil surfaces at the rear end of the formed group,

a second welding means which welds the last-mentioned foil surfaces,

a second conveyor means which transports the formed group to said second welding means,

the foil made of a plastic material which is shrinkable on heating,

the distribution Wheel coacting with a number of compartments each of which accommodates a row of containers with the number of compartments corresponding to the number of recesses in each group and each compartment having an Opening facing the periphery of the Wheel in such a way that containers from recesses with the same depths are fed into the same compartment.

4. The machine according to claim 3 with the compartments parallel to each other and arranged beside each other.

5. The machine according to claim 4 with:

the blocking means comprising a transverse plate arranged across output openings of the compartments, the plate by means of a mechanism containing linkages of a parallelogram type is moveable between two vertical positions one of which coincides with the floor of the compartments and the other located at a sufiicient height above said floor that feeding of containers from the compartments is blocked.

6. The machine according to claim 5 with:

the compartments defined by outer walls and at least one intermediate wall,

the plate having at least one wall-extension member which penetrates between compartments to form an extension of the intermediate wall.

7. The machine according to claim 3 with:

the compartments defined by outer walls and at least one intermediate wall,

the first conveyor means comprising said outer walls and a pushing member which is moveable into each compartment.

8. The machine according to claim 7 with said outer walls each provided at its front end with a finger that can be pressed downward under spring action whereby on movement of the first conveyor means the fingers move away the foil in front of a formed group.

9. The machine according to claim 8 with fingers coacting with the pushing member when a formed group is fed forward and with the fingers located on each side thereof to move aside the foil.

10. The machine according to claim 9 with a line fastened to the end of each finger and urged parallel to the direction of movement of the first conveyor means so that the two lines prevent transverse movement of a formed group.

11. The machine according to claim 1 with:

the second conveyor means comprises two fork-like members arranged transversely in relation to the formed group which they are to convey,

the fork-like members displaceable transversely to retain and release the formed group.

12. The machine according to claim 11 with a blower unit arranged between the first and second welding means to put the foils which are to be welded into contact with each other.

13. The machine according to claim 12 with:

a stretching unit arranged between the first and second welding units,

the stretching unit comprising transversely opposed parts each of which contains two stick members and control devices connected thereto,

the control devices operable to insert the pairs of sticks into lateral openings of the foil casing and thereafter give the pairs of sticks such a movement that the endless edge of each lateral opening is set in such a position that two edge surfaces in contact with each other are obtained.

14. The machine according to claim 13 with each pair of sticks given a movement only in a vertical plane by its control device.

15. The machine according to claim 14 with:

each of the sticks in a :pair supported in one end of an arm in such a way that they can turn in a plane at right angles to the longitudinal axis of the arm,

the other end of said arm being supported so that it can turn around an axle at right angles to the direction in which a formed group is conveyed,

the free ends of the two arms located exactly opposite each other when the sticks are in a vertical plane.

16. The machine according to claim 15 with a blocking member arranged at each pair of arms whereby at their starting position the sticks are prevented from leaving their vertical plane.

References Cited UNITED STATES PATENTS 2,885,841 5/1959 Currie et al. 5348 X 3,239,991 3/1966 Copping 534-.8 X

FOREIGN PATENTS 996,580 6/1965 Great Britain.

THERON E. CONDON, Primary Examiner 0 E. F. DESMOND, Assistant Examiner U.S. Cl. X.R.