Apparatus For Loading Containers

Abstract

There is disclosed a method and an apparatus for loading containers with single pieces by which a plurality of single pieces are stacked on top of each other and subsequently several stacks are assembled into a block having a size substantially corresponding to the dimensions of the freight space of the container. In one embodiment, the pieces are enveloped in plastic sheet prior to stacking. Two containers may be loaded alternately. The apparatus comprises one or several stacking devices for stacking the single pieces, a packing device if desired and various conveyors and transfer devices for feeding the stacks to a tilting frame on which the container may be mounted. Loading of the assembled blocks of single pieces into the container is effected by tilting the tilting frame. The drive means of the various devices may be coupled through control means to a common program controller.

Description

DESCRIPTION OF THE INVENTION

The present invention relates to a method and an apparatus for loading containers with single pieces assembled in stacks. Heretofore, packing goods were stacked on pallets, and then these pallets were loaded into the containers. A drawback of such an arrangement is, however, that the plan dimensions of the pallets are such that the container interior cannot be filled entirely with the goods stacked on pallets. The unoccupied spaces in the containers are then filled with air bags or the like, in order to prevent shifting of the contents therein. Such expedients and the uncomplete filling of the container interior render the transport of piece goods in containers uneconomical.

It is therefore the object of the present invention to provide an improved method and apparatus for loading containers with single pieces assembled in stacks, by which not only packages that are adapted to container transport may be formed but also the packing goods may be arranged in a manner allowing to make use of the whole internal space of the container.

For achieving this object the present invention proposes a method of loading containers with single pieces according to which for stacking two single pieces one on top of another, a single piece is withdrawn from a series of single pieces supplied and deposited on top of the next following single piece in the series, subsequently several stacks consisting of two single pieces stacked one on top of the other are combined side by side and one stack behind another stack into a block having a size corresponding to the internal dimensions of the container, and finally conveying such blocks by means of gravity feed towards and into the containers. Prior to stacking the single pieces one on top of another the single pieces may be enveloped in synthetic sheet. It is likewise feasible, prior to preparing the stacks for loading into the containers, to stack several single pieces one on top of another, in order to obtain stacks the height of which corresponds to the height of the container interior. If two containers are used, the containers are loaded alternately.

The apparatus according to the present invention for practicing the method of loading containers with single pieces assembled in stacks is characterized by a roller conveyor having driven rollers for feeding single pieces; a stacking device for stacking a single piece on top of another single piece, the stacking device arranged adjacent the roller conveyor and comprising a frame, a lifting platform vertically movable in the frame, lifting forks on the lifting platform at the end of the platform facing the roller conveyor and adapted to be lowered between the rollers of the roller conveyor when the lifting platform is in its lowered position, and control devices arranged adjacent the stacking device in the path of movement of the single pieces on the roller conveyor and adapted to be actuated by the single pieces, the control devices coupled to drive means for lifting and lowering the lifting platform; a transfer and storage conveyor arranged transversely of the roller conveyor at the discharge side of the roller conveyor, the transfer and storage conveyor comprising a pair of roller tracks arranged one behind the other with an intermediate spacing corresponding substantially to the width of the first-mentioned roller conveyor adjacent the stacking device, and transfer devices for the stacks formed of two single pieces one on top of the other whereby the roller tracks are mounted in carriage type frames movable by means of drive means transversely of the first-mentioned roller conveyor; a pair of tilting frames tiltable about their mid portions and arranged such that each tilting frame is opposite to an outer end portion of one roller track of the pair of roller tracks of the transfer and storage conveyor and extends transversely thereof, each tilting frame including a first frame section facing the transfer and storage conveyor and connected at its lower side to a lifting device, a roller track in the first section having rollers extending parallel to the rollers of the pair of roller tracks and a second frame section in the extension of the tilting frame roller track and which is arranged in the form of a support plate for a container.

For stacking several single pieces one on top of another, there may be arranged, according to another feature of the present invention, several stacking devices adjacent the first-mentioned roller conveyor.

For alternately loading two conveyors, the rollers of the pair of roller tracks of the transfer and storage conveyor may be mounted, according to another feature of the present invention, in the movable carriage type frames such that when moving the pair of roller tracks these rollers may pass between the rollers of the first-mentioned roller conveyor which extends intermediate of the pair of roller tracks of the transfer and storage conveyor whereby the discharge ends of the roller tracks for feeding the single pieces extend into the spacing between the pair of roller tracks of the transfer and storage conveyor.

For loading the containers with single pieces packed in synthetic sheet whereby such single pieces may also be assembled in stacks if the single pieces are of a smaller size, a device of a type known per se for packing the single pieces in synthetic sheet or heat shrinkable thermoplastic sheet may be mounted upstream of the roller conveyor having the stacking devices adjacent thereto.

According to another feature of the present invention the drive means of the stacking devices, of the pair of movable roller tracks of the transfer and storage conveyor, of the tilting frames with the containers, of the transfer devices for transferring the stacks from the movable roller tracks of the transfer and storage conveyor onto the roller tracks of the tilting frames, and of the first-mentioned roller conveyor are coupled to control means for controlling the various movements, and the control means are combined in a program controller.

The appended drawing shows a perspective view of an embodiment of an apparatus for loading containers with single pieces assembled in stacks according to the present invention. In the drawing, FIG. 1a is a left-hand section of the apparatus, and

FIG. 1b is a right-hand section of the same apparatus as seen from the dashed dividing line.

The apparatus of the present invention comprises a roller conveyor 10 for feeding a series of single pieces E one following another. The rollers 11 of the roller conveyor 10 are preferably individually power-driven and feed the single pieces in the direction of the arrow x. The discharge side of the roller conveyor 10 is designated by 10a.

A device 15 for stacking two single pieces E one on top of another is arranged adjacent the roller conveyor 10 and comprises a frame 16 with a lifting platform 17 which may be raised and lowered by means of a drive motor 19. The free end 17a of the lifting platform 17 facing the roller conveyor 10 is provided with lifting forks 17b adapted to be lowered between the rollers 11 of the roller conveyor 10 so that in the lower position of the lifting platform 17 the lifting forks are interposed between the rollers 11 of the roller conveyor 10. A single piece which has been moved into a position overlying the lifting forks 17b will be lifted off the roller conveyor 10 when raising the lifting platform 17. The single piece is lifted by the lifting platform 17 into an elevated position in which the lifted single piece is elevated above a next following single piece fed by the roller conveyor 10. Control devices 18, preferably in the form of light barriers on either side of the roller conveyor 10 and adapted to control the lifting platform 17 are mounted in the vicinity of the stacking device 15. These control devices 18 may be actuated by single pieces supplied by the roller conveyor 10 and are connected to the power drive 19 for raising and lowering the lifting platform 17.

If it is desired to stack several single pieces one on top of another, several stacking devices 15 may be arranged adjacent the roller conveyor 10.

A transfer and storage conveyor 20 is arranged transversely of the roller conveyor 10 at the discharge end 10a thereof. By means of the transfer and storage conveyor 20 single pieces already assembled in stacks may be directed to the various containers on the one hand, and stacks assembled to blocks B may be prepared and made ready for loading on the other hand. These blocks B correspond in their sizes to the dimensions of the containers to be loaded. This transfer and storage conveyor 20 consists of a pair of roller tracks 21, 22 mounted one behind the other with an intermediate spacing corresponding approximately to the width of the roller conveyor 10. The roller tracks 21, 22 with their driven rollers 23, 24 are mounted in carriage type frames 27, 28 which are movable on guide rails transversely of the roller conveyor 10 by means of drive means 27a, 28a. Transfer devices 25, 26 are arranged in the vicinity of the roller tracks 21, 22. Each transfer device consists of a push plate connected by actuation links to a drive means such as a jack or the like. Alternatively, instead of the movable roller tracks 21, 22 there may also be provided other suitable means for transferring the single pieces assembled in stacks S onto the one or the other end of the transfer and storage conveyor 20. The roller conveyor 10 preferably extends into the clearance between the pair of roller tracks 21, 22. The rollers 23, 24 of the pair of roller tracks 21, 22 of the transfer and storage conveyor 20 are mounted in the movable carriage type frames 27, 28 in such a manner that the rollers 23, 24 may pass between the rollers 11 of the roller conveyor 10 when shifting the roller tracks 21, 22. Entrainment dogs (not shown) at the movable carriage type frames 27, 28 serve to take along the stacks S when moving the roller tracks 21, 22.

A pair of parallel spaced tilting frames 30, 31 are mounted such that the one end of each tilting frame is opposite to an outer end portion of a roller track 21, 22 of the pair of roller tracks so that stacks S resting on the roller tracks 21, 22 may be transferred onto these tilting frames 30, 31 by means of the transfer devices 25, 26. Instead of using the transfer devices 25, 26 for transferring the stacks S, the rollers 23, 24 of the roller tracks 21, 22 may be power-driven. The tilting frames 30, 31 are tiltably mounted in the vicinity of their mid portions in suitable bearing blocks 32, 33. The frame sections 30a, 31a of the frames 30, 31 facing the transfer and storage conveyor 20 are each provided with a roller track 35, 36 respectively, and the rollers 37, 38 in these roller tracks 35, 36 extend parallel to the rollers 23, 24 of the roller tracks 21, 22 of the transfer and storage conveyor 20 and the rollers 11 of the roller conveyor 10. The tilting frames 30, 31 are each connected, at the lower side of the section containing the roller track 35, 36, with a lifting device of which the lifting device 34 for the tilting frame 30 may be seen in the drawing. The roller tracks 35, 36 extend along about the front halves of the tilting frames 30, 31 respectively, i.e., those frame sections facing the transfer and storage conveyor 20. The rear halves of the tilting frames 30, 31, i.e., the frame sections 30b, 31b are arranged in the form of support plates 40, 41 for the containers C.

If the singe pieces or single pieces assembled in stacks intended to be loaded into the containers C are to be packed in sheeting a device 50 of a type known per se for packing the single pieces in synthetic sheeting is arranged upstream of the roller conveyor 10. This packing device 50 consists of a frame 51 with two feed tracks 52, 53 for feeding the packing good in the directions of the arrows x.sub.1 and x.sub.2. A sheeting supply drum 54 is mounted in the upper portion of the frame 51, and another sheeting supply drum 55 is mounted in the lower portion of the frame 51. The sheeting F is guided by a corresponding number of deflector rollers in such a manner that a sheeting wall is formed transversely of the feed direction of the packing good. The packing good is then advanced into this sheeting wall by means of transfer devices not shown in the drawing but which may be formed similar to the transfer devices 25, 26. From the feed tracks 52, 53 the packing good is transferred onto a discharge conveyor 57. A welding device 56 is mounted between the sheeting wall and the discharge conveyor 57. The welding device 56 comprises an upper and a lower welding jaw. These two welding jaws are coupled to drive means for moving the welding jaws towards and away from each other. The welding device 56 is furthermore provided with a severing device such a severing knife, a hot wire or the like by means of which the packing good enveloped in the sheet may be severed from the sheeting supply subsequently to the welding operation. Preferably the welding jaws of the welding device 56 are of a type producing a double weld. Severing of the sheet sleeve from the sheeting supply will then be effected between these two welds.

Further welding devices 58, 59 are arranged on either side of the discharge conveyor 57. The additional welding devices are of a type similar to the welding device 56 and serve to seal the lateral open edges of the sheet sleeve enveloping the packing good. If the packing sheet consists of a heat shrinkable thermoplastic synthetic sheeting another feed conveyor 60 and a shrinkage tunnel 61 are arranged downstream of the discharge conveyor 57. This feed conveyor 60 is then followed at its downstream side by the roller conveyor 10.

The drive means of the stacking device 15, of the movable roller tracks 21, 22 of the transfer and storage conveyor 20, of the tilting frames 30, 31 with the containers thereon, of the transfer devices 25, 26 and of the rollers of the roller conveyor 10 are coupled to control means (not shown), and the control means are combined in a program controller (not shown). The program controller may also serve to control the control members of the packing device 50 which is mounted on the upstream side of the loading apparatus so that the entire packing and loading operation may be centrally controlled and performed in a fully automatic manner.

The operation of the loading apparatus according to the present invention is as follows: The non-packed or sheet-packed single pieces E or single pieces assembled in stacks are supplied to the stacking device 15 by means of the roller conveyor 10. When actuating the control members 18, the respective single piece is lifted by the stacking device 15 and deposited on top of the next following single piece in the series of single pieces supplied. The control members 18 may also be coupled to a stepping mechanism (not shown) which controls the incremental feed of the single pieces E and the raising and lowering of the lifting platform 17 of the stacking device 15. The single pieces E assembled in stacks S are then transported by means of the roller conveyor 10 to the transfer and storage conveyor 20 and are moved by the latter towards the conveyor section opposite to the container which is to be loaded. The stacks S are then transferred by means of the transfer device 26 onto the roller track 36 of the tilting frame 31 and on this roller track 36 assembled to a block B which at the end of the assembling operation is of a size corresponding to the dimensions of the interior of the container C. During the stacking of the individual stacks S into a block B, the tilting frame 31 is in a horizontal position. During transfer of the block B into the container C which is open at its near end the transfer and storage conveyor 20 is shifted so that any further stacks S supplied may be transferred onto the roller track 35 of the tilting frame 30. After assembly of the block B on the roller track 36 the tilting frame 31 is tilted by means of the lifting device associated therewith, i.e., the roller track 36 with the block B of single pieces assembled thereon is lifting so that the block B is transferred by gravity into the container C. The tilting frame 30 is shown in this loading position in the drawing.

By alternately loading two containers C in using a transfer and storage conveyor an economical loading of containers may be achieved, the loading may be carried out in a minimum time and with a very high efficiency. By assembling the single pieces E to stacks S or blocks B respectively it is moreover possible to make use of the entire interior space of the containers C so that no available loading space is wasted. If the single pieces consist for example of sacks these single pieces may also be assembled in compound stacks. By the fact that the single pieces or the single stacks are wrapped in plastic sheet no pallets need to be employed. Single pieces having various sizes may likewise be assembled by means of the apparatus of the present invention in a manner achieving an efficient utilization of the containers. The transfer and storage conveyor 20 furthermore allows to reject single pieces having a size unsuitable for assembling an integral block of a size corresponding as nearly as possible to the interior dimensions of the container, and to set such single pieces aside for assembling another block B to be loaded into the second container. The various devices of the overall apparatus may also be combined in a single machine frame.

Claims

What is claimed is:

1. An apparatus for stacking and subsequently loading pieces into a container,

comprising, in combination,

a first conveyor operable for feeding successive pieces in one direction,

a stacking device disposed near the first conveyor and being operable for lifting a piece from the feeding conveyor and stacking it on another piece;

control means operative for controlling the operation of the stacking device in response to the position on the conveyor in its movement in said one direction of a succeeding piece prior to its reaching the stacking device,

a second conveyor cooperating with a discharging part of the first conveyor to receive therefrom succeeding stacks and to move the stacks in a direction at an angle to said one direction,

at least one support movable between a transfer position in which it is operable to receive at one portion stacks from the second conveyor and, respectively, a loading position at an angle to said transfer position, and

transfer means operable for transferring the stacks from the second conveyor onto said one portion of the support when the support is in the transfer position,

said support being adapted to support at another portion a container, whereby during movement of said support from said transfer position to said loading position, the stacks will be shifted from said one portion of the support towards said other portion and be loaded into the container.

2. An apparatus according to claim 1, wherein said first conveyor is a roller conveyor, said stacking device being arranged adjacent the roller conveyor and comprising a frame, a lifting platform vertically movable in said frame, lifting forks on said lifting platform at the end of the platform facing the roller conveyor and adapted to be lowered between the rollers of the roller conveyor when the lifting platform is in its lowered position,

said control means including control devices arranged adjacent the stacking device in the path of movement of the single pieces on the roller conveyor and adapted to be actuated by the single pieces, the control devices coupled to drive means for lifting and lowering the lifting platform;

said second conveyor being a transfer and storage conveyor arranged transversely of the roller conveyor at the discharge side of the roller conveyor, and including a pair of roller tracks arranged one behind the other with an intermediate spacing corresponding substantially to the width of said first roller conveyor adjacent the stacking device, and transfer devices for the stacks formed of two single pieces one on top of the other whereby said roller tracks are mounted in carriage type frames movable by means of drive means transversely of said first roller conveyor;

said support including a pair of tilting frames tiltable about their mid portions and arranged such that each tilting frame is opposite to an outer end portion of one roller track of said pair of roller tracks of said transfer and storage conveyor and extends transversely thereof, each tilting frame including a first frame section facing the transfer and storage conveyor and connected at its lower side to a lifting device, a roller track in said first section having rollers extending parallel to the rollers of said pair of roller tracks and a second frame section in the extension of the tilting frame roller track and which is arranged in the form of a support plate for a container.

3. An apparatus as in claim 1 wherein several stacking devices are arranged adjacent the first conveyor.

4. An apparatus as in claim 2 wherein the rollers of the pair of roller tracks of the transfer and storage conveyor are mounted in the movable carriage type frames such that when moving said pair of roller tracks these rollers may pass between the rollers of the first-mentioned roller conveyor which extends intermediate of said pair of roller tracks of said transfer and storage conveyor.

5. An apparatus as in claim 1 further including a device for packing the single pieces in synthetic sheet or heat shrinkable thermoplastic sheet, said device being mounted upstream of the first conveyor and operable for supplying a succession of packed single pieces thereon.

6. An apparatus as in claim 2 wherein the drive means of the stacking device, of the pair of movable roller tracks of the transfer and storage conveyor, of the tilting frames with the containers, of the transfer devices for transferring the stacks from the movable roller tracks of the transfer and storage conveyor onto the roller tracks of the tilting frames, and of the first-mentioned roller conveyor are coupled to additional control means for controlling the various movements, and the control means are combined in a program controller.

7. An apparatus as in claim 2 wherein the rollers in said pair of roller tracks are individually power-driven.