FULLY AUTOMATIC APPARATUS FOR LOADING CONTAINERS WITH SINGLE PIECES ASSEMBLED IN SHEET-WRAPPED STACKS, SUCH AS SACKS OR THE LIKE
United States Patent 3727369
An apparatus for fully automatically assembling single pieces in stacks by means of a pair of stacking devices in which several single pieces are arranged side by side in the form of a layer and several layers are formed one on top of another, then wrapping and sealing such stacks in synthetic sheet by means of a sheet packing device, then stacking such stacks one on top of another stack or stacking several stacks on top of each other to form compound stacks by means of one or several stacking devices, then assembling such compound stacks into blocks of sizes corresponding substantially to the dimensions of the interior cargo space of a container by means of a transfer and storage conveyor, and finally sliding such blocks into the containers. In one embodiment, the stacks are wrapped in plastic sheet prior to compound stacking. Two containers may be loaded alternately. The apparatus comprises various conveyors and transfer devices for feeding the single pieces, the stacks, the compound stacks and the assembled blocks through the apparatus to tilting frames on which the containers may be mounted. The drive means of the various devices and conveyors may be coupled through control means to a common program controller.
US Patent References:
Apparatus for stacking articles in predetermined orientation
Maramonte et al. - April 1966 - 3245557
/3570209.html
Salwasser - March 1971 - 3570209
PACKAGING MACHINE
Monaghan - January 1970 - 3490194
RETARDER MECHANISM
Adams - April 1972 - 3653177
Mechanism for transporting loads
Small et al. - August 1952 - 2605912
Apparatus for stacking articles in predetermined orientation
Maramonte et al. - April 1966 - 3245557
/3570209.html
Salwasser - March 1971 - 3570209
PACKAGING MACHINE
Monaghan - January 1970 - 3490194
RETARDER MECHANISM
Adams - April 1972 - 3653177
Mechanism for transporting loads
Small et al. - August 1952 - 2605912
Application Number:
05/165676
Publication Date:
04/17/1973
Filing Date:
07/23/1971
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
53/548, 53/540, 53/557
International Classes:
B65G67/04; B65G67/02; B65B35/52
Field of Search:
53/159,182,184 214/6P
Primary Examiner:
Mcgehee, Travis S.
Assistant Examiner:
Sipos, John
Claims:
What is claimed is
1. A fully automatic apparatus for loading containers with single pieces assembled in sheet-wrapped stacks, such as sacks or the like, said apparatus characterized by the combination of:
2. An apparatus as in claim 1 wherein several stacking devices are arranged adjacent the roller conveyor which is located downstream of said shrinkage tunnel discharge conveyor.
3. An apparatus as in claim 1 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 roller conveyor downstream of said shrinkage tunnel conveyor and which extends intermediate of said pair of roller tracks of said transfer and storage conveyor.
1. A fully automatic apparatus for loading containers with single pieces assembled in sheet-wrapped stacks, such as sacks or the like, said apparatus characterized by the combination of:
2. An apparatus as in claim 1 wherein several stacking devices are arranged adjacent the roller conveyor which is located downstream of said shrinkage tunnel discharge conveyor.
3. An apparatus as in claim 1 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 roller conveyor downstream of said shrinkage tunnel conveyor and which extends intermediate of said pair of roller tracks of said transfer and storage conveyor.
Description:
DESCRIPTION OF THE INVENTION
The present invention relates to a fully automatic apparatus for loading containers with single pieces assembled in sheet-wrapped stacks, such as sacks or the like.
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 pallet 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 a fully automatic apparatus for loading containers with single pieces in sheet-wrapped 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 an apparatus for loading containers which apparatus is characterized by the combination of:
A. a pair of devices for the compound stacking of the single pieces, each stacking devices comprising an elevated feed conveyor for feeding the single pieces, a transfer bar extending parallel to the direction of movement of the feed conveyor, the transfer bar being movable perpendicularly to the conveyor feed direction, and a packing plate extending parallel to the feed conveyor and serving as a transfer member operatively associated with a lifting platform, the platform adapted to be raised or lowered, the pair of stacking devices being arranged opposite to each other and mutually connected by a pair of roller tracks, each roller track of the pair of roller tracks being associated with one stacking device of the pair of stacking devices whereby the pair of roller tracks extend at a lower elevation than the elevated feed conveyors, and a roller conveyor serving as a transfer conveyor, and rollers of which extend transversely of the rollers in the pair of roller tracks, the roller conveyor being arranged in between the inner adjacent ends of the pair of roller tracks;
b. a device for packing the stacks of single pieces in synthetic sheet or respectively in heat shrinkable thermoplastic sheet, the packing device mounted downstream of the transfer conveyor and including a frame, a pair of sheeting supply drums mutually spaced one above the other and adapted to form a vertical sheet curtain extending transversely of the feed direction of the stacks, a welding and severing device on the downstream side of the sheet curtain, a discharge conveyor and welding devices mounted on opposite sides of the discharge conveyor and adapted to seal the lateral open edges of a sheet sleeve wrapped around a stack;
c. a shrinkage tunnel having a separate discharge conveyor, both arranged downstream of the packing device;
d. a roller conveyor having driven rollers arranged downstream of the shrinkage tunnel with the discharge conveyor, a stacking device for stacking a stack on top of another stack, 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 stacks on the roller conveyor and adapted to be actuated by the stacks, the control devices coupled to drive means for raising and lowering the lifting platform;
e. 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 roller conveyor adjacent the stacking device, and transfer devices for the stacks whereby the roller tracks are mounted in carriage type frames movable by means of drive means transversely of the roller conveyor;
f. 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;
e. and whereby the drive means of the feed and discharge conveyors, of the devices for the compound stacking of the single pieces, of the stacking device for stacking a stack on top of another stack, of the 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 roller conveyor downstream of the shrinkage tunnel conveyor are coupled to control means for controlling the various movements, and the control means are combined in a program controller.
For alternately loading two containers, 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 roller conveyor along which the stacking devices are arranged 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.
A preferred illustrative embodiment of the present invention is shown in the appended drawing wherein
FIG. 1a, 1b and 1c are schematic view of the overall apparatus;
FIG. 2 is a top view of an independently operating device for the compound stacking of single pieces, and
FIG. 3 is a lateral elevational view of the device shown in FIG. 2.
The apparatus of the present invention comprises a pair of devices 10 and 10a for the compound stacking of the single pieces supplied such as sacks, a device 150 for packing the individual stacks in sheet material, a stacking device 115 for putting a stack S on top of another stack S, a transfer and storage conveyor 120 for alternately loading two containers C and a pair of container loading devices 130, 131.
As may be seen in FIG. 1b, the pair of stacking devices 10 and 10a are disposed opposite to each other and are mutually spaced. The two stacking devices 10, 10a are identical. In the following, only the stacking device 10 will be described. All parts of the device 10a corresponding to similar parts of the device 10 are designated by similar reference numerals with the appended letter "a."
The stacking device 10 comprises a feed conveyor 11 for feeding the single pieces. The feed conveyor 11 is mounted in a frame 12. Additional feed conveyors 13, 14 may be arranged upstream of the feed conveyor 11. These additional feed conveyors 13, 14 may serve to bring up the sacks from a filling station indicated at 15. The feed conveyor 11 then conveys the sacks into a zone in which the sacks may be transferred onto a discharge conveyor 16 which extends at a lower elevation than the feed conveyor 11. By means of a guide 17 consisting of a swingable plate and an abutment pin 18 disposed above the feed conveyor 11 the sacks may be rotated as required for the compound stacking (FIG. 2). The sacks then enter a space defined on one side by a rear abutment bar 20 which extends parallel to a return roller of the feed conveyor 11. Within this space, the sacks are made ready for the transfer onto a packing plate 22.
A transfer bar 21 extending parallel to the direction of movement of the feed conveyor 11 serves to transfer a layer of sacks onto a packing plate 22 disposed in the plane defined by the feed conveyor 11 and adjacent thereto. The packing plate 22 is located above a lifting platform 25. The size of the packing plate 22 corresponds approximately to the size of the lifting platform, and the packing plate has preferably a very small thickness, i.e., height. The packing plate 22 is movable in a direction parallel to the movement direction of the feed conveyor, and the lower surface of the packing plate is preferably curved outwardly from the edges towards the center of the lower surface.
The lifting platform 25 may be raised and lowered whereby during this movement the lifting platform is guided in lateral guides 26 of the base frame 19. The overall arrangement is such that when withdrawing the packing plate 22 from below a layer of sacks the sacks may be transferred onto the lifting platform 25 without undergoing any substantial deformation (FIG. 3). After loading with sacks, the lifting platform 25 is lowered by a distance corresponding to the height of one sack layer thus providing sufficient clearance for the next following sack layer and allowing to return the packing plate 22 into its loading position. To obtain a more compact stacking, every sack layer is pressed against the lower surface of the packing plate 22 which has been returned into its discharge position, by raising the platform 25 together with the sack layers already deposited thereon, and the sack layer is held in this condition until the packing plate 22 is again withdrawn.
The movements of the packing plate 22 and the lifting platform 25 are preferably coordinated in such a fashion that after withdrawing the packing plate 22 the lifting platform 25 is lowered by a distance corresponding to the height of the sack layer which has just been deposited thereon. Then the packing plate is returned into its loading position. While a new sack layer which has been prepared in the meantime is pushed by means of the transfer bar 21 onto the packing plate 22, the lifting platform 25 is raised, in pressing the uppermost sack layer thereon against the downwardly bulging surface at the bottom of the packing plate 22 and thereby deforming the upper surface defined by the sack layer resting on the platform. Then the packing plate is withdrawn, and the newly formed sack layer transferred onto the lifting platform 25.
The packing device 150 which will be described further below and a roller conveyor 110 having the stacking device 115 adjacent thereto are arranged downstream of the transfer conveyor 152. A device 115 for stacking two stacks S one on top of another is arranged adjacent the roller conveyor 110 and comprises a frame 116 with a lifting platform 117 which may be raised or lowered by means of a drive motor 119. The free end 117a of the lifting platform 117 facing the roller conveyor 110 is provided with lifting forks 117b adapted to be lowered between the rollers 111 of the roller conveyor 110 so that in the lower position of the lifting platform 117 the lifting forks are interposed between the rollers 111 of the roller conveyor 110. A stack S which has been moved into a position overlaying the lifting forks 117b will be lifted off the roller conveyor 110 when raising the lifting platform 117. The stack is lifted by the lifting platform 117 into an elevated position in which the lifted stack S is elevated above a next following stack fed by the roller conveyor 110. Control devices 118, preferably in the form of light barriers on either side of the roller conveyor 110 and adapted to control the movement of the lifting platform 117 are mounted in the vicinity of the stacking device 115. These control devices 118 may be actuated by stacks S supplied by the roller conveyor 110 in the direction of the arrow x and are connected to the power drive 119 for raising and lowering the lifting platform 117. Sensing elements detecting the height of the stacks S supplied and transmitting this information to control means (not shown) coupled to the drive motor 119 of the lifting platform 117 for controlling the lifting position of the platform 117 may be arranged above the roller conveyor 110.
If it is desired to put several stacks one on top of another, several stacking devices 115 may be arranged adjacent the roller conveyor 110.
A transfer and storage conveyor 120 is arranged transversely of the roller conveyor 110 at the discharge end 110a thereof. By means of the transfer and storage conveyor 120 already assembled compound stacks G may be directed to the various containers on the one hand, and compound stacks G may be assembled into blocks B 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 120 consists of a pair of roller tracks 121, 122 mounted one behind the other with an intermediate spacing corresponding approximately to the width of the roller conveyor 110. The roller tracks 121, 122 with their driven rollers 123, 124 are mounted in carriage type frames 127, 128 which are movable on guide rails transversely of the roller conveyor 110 by means of drive means 127a, 128a. Transfer devices 125, 126 are arranged in the vicinity of the roller tracks 121, 122. 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 121, 122 there may also be provided other suitable means for transferring the compound stacks G onto the one or the other end of the transfer and storage conveyor 120. The roller conveyor 110 preferably extends into the clearance between the pair of roller tracks 121, 122. The rollers 123, 124 of the pair of roller tracks 121, 122 of the transfer and storage conveyor 120 are mounted in the movable carriage type frames 127, 128 in such a manner that the rollers 123, 124 may pass between the rollers 111 of the roller conveyor 110 when shifting the roller tracks 121, 122. Entrainment dogs (not shown) at the movable carriage type frame 127, 128 serve to take along the compound stacks G when moving the roller tracks 121, 122.
A pair of parallel and mutually spaced tilting frames 130, 131 is mounted such that the one ends of the tilting frames are opposite to outer end portions of a roller track 121 or 122 respectively of the pair of roller tracks so that stacks G resting on the roller tracks 121, 122 may be transferred onto these tilting frames 130, 131 by means of the transfer devices 125, 126. Instead of using the transfer devices 125, 126 for transferring the compound stacks G, the rollers 123, 124 of the roller tracks 121, 122 may be power-driven. The tilting frames 130, 131 are tiltably mounted in the vicinity of their mid portions in suitable bearing blocks 132, 133. The frame sections 130a, 131a of the frames 130, 131 facing the transfer and storage conveyor 120 are each provided with a roller track 135, 136 respectively, and the rollers 137, 138 in these roller tracks 135, 136 extend parallel to the rollers 123, 124 of the roller tracks 121, 122 of the transfer and storage conveyor 120 and the rollers 111 of the roller conveyor 110. The tilting frames 130, 131 are each connected, at the lower side of the section containing the roller track 135, 136 respectively, with a lifting device of which the lifting device 134 for the tilting frame 130 may be seen in the drawing (FIG. 1c). The roller tracks 135, 136 extend along about the front halves of the tilting frames 130, 131 respectively, i.e., those frame sections facing the transfer and storage conveyor 120. The rear halves of the tilting frames 130, 131, i.e., the frame sections 130b, 131b are arranged in the form of support plates 140, 141 for the containers C.
The device 150 for packing the stacks S in synthetic sheet consists of a frame 151 with the two feed tracks 16, 16a for feeding the packing goods in the direction of the arrows x 1 and x 2 respectively. A sheeting supply drum 154 is mounted in the upper portion of the frame 151, and another sheeting supply drum 155 is mounted in the lower portion of the frame 151. The sheeting F is guided by a corresponding number of deflector rollers in such a manner that a vertical sheeting wall is formed transversely of the feed direction of the stacks S. The packing goods are 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 125, 126. From the feed tracks 16, 16a the packing goods are transferred onto a discharge conveyor 157. A welding device 156 is mounted between the sheeting wall and the discharge conveyor 157. The welding device 156 comprises an upper welding jaw 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 156 is furthermore provided with a severing device such as a severing knife, a hot wire or the like by means of which the sheet sleeve M enveloping the packing good after welding may bex severed from the sheeting supply subsequently to the welding operation. Preferably the welding jaws of the welding device 156 are of a type producing a double weld. Severing of the sheet sleeve from the sheeting supply will then be effected intermediate these two welds.
Further welding devices 158, 159 are arranged on either side of the discharge conveyor 157. The additional welding devices are of a type similar to the welding device 156 and serve to seal the lateral open edges of the sheet sleeve enveloping the packing goods. If the packing sheet consists of a heat shrinkable thermoplastic synthetic sheeting, another feed conveyor 160 and a shrinkage tunnel 161 are arranged downstream of the discharge conveyor 157. This feed conveyor 160 is then followed, at its downstream side, by the roller conveyor 110.
The drive means of the feed and discharge conveyors 13, 14, 11, 11a, 16, 16a of the devices 10, 10a for the compound stacking of the single pieces, of the stacking device 115, of the movable roller tracks 121, 122 of the transfer and storage conveyor 120, of the tilting frames 130, 131 with the containers C thereon, of the transfer devices 125, 126 and of the rollers of the roller conveyor 110 are coupled to control means (not shown) for controlling the various movements, 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 sheet packing device 150 which is located upstream of the loading apparatus stacking device so that the entire packing and loading operation as well as the packing may be centrally controlled and performed in a fully automatic fashion.
The operation of the loading apparatus according to the present invention is as follows: The stacks packed in sheet material are supplied to the stacking device 115 by means of the roller conveyor 110. When actuating the control members 118, the respective stack S is lifted by the stacking device 115 and deposited on top of the next following stack in the series of stacks supplied. The control members 118 may also be coupled to a stepping mechanism (not shown) which controls the incremental feed of the stacks S and the raising and lowering of the lifting platform 117 of the stacking device 115. The compound stacks G are then transported by means of the roller conveyor 110 to the transfer and storage conveyor 120 and are moved by the latter towards the conveyor section opposite to the container which is to be loaded. The stacks G are then transferred by means of the transfer device 126 onto the roller track 136 of the tilting frame 131 and on this roller track 136 assembled into a block B which at the end of the assembling operation is of a size corresponding to the dimensions of the interior cargo space of the container C. During the stacking operation of the individual compound stacks G into a block B, the tilting frame 131 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 120 is shifted so that any further compound stacks G supplied may be transferred onto the roller track 135 of the tilting frame 130. After assembly of the block B on the roller track 136 the tilting frame 131 is tilted by means of the lifting device associated therewith, i.e., the roller track 136 with the block B of compound stacks G assembled thereon is lifted so that the block B is transferred by gravity into the container C. The tilting frame 130 is shown in this loading position in FIG. 1c of 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 since the single pieces assembled in stacks by means of the pair of stacking devices 10, 10a are alternately supplied to the packing device 150. By assembling the single pieces E into stacks S or compound stacks G 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. By the fact that the single stacks are wrapped or enveloped in plastic sheet material no pallets need to be employed. Single stacks having various sizes may likewise be assembled by means of the apparatus of the present invention in such a manner achieving an efficient utilization of the containers. The transfer and storage conveyor 120 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 stacks aside for assembling another block B by means of stacks of suitable sizes which block is then loaded into the second container. The various devices of the overall apparatus may also be combined in a single machine frame.
Having thus described the invention, it will be apparent that various modifications may be made to the invention without departing from the scope thereof as set forth in the claims appended hereto.
The present invention relates to a fully automatic apparatus for loading containers with single pieces assembled in sheet-wrapped stacks, such as sacks or the like.
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 pallet 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 a fully automatic apparatus for loading containers with single pieces in sheet-wrapped 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 an apparatus for loading containers which apparatus is characterized by the combination of:
A. a pair of devices for the compound stacking of the single pieces, each stacking devices comprising an elevated feed conveyor for feeding the single pieces, a transfer bar extending parallel to the direction of movement of the feed conveyor, the transfer bar being movable perpendicularly to the conveyor feed direction, and a packing plate extending parallel to the feed conveyor and serving as a transfer member operatively associated with a lifting platform, the platform adapted to be raised or lowered, the pair of stacking devices being arranged opposite to each other and mutually connected by a pair of roller tracks, each roller track of the pair of roller tracks being associated with one stacking device of the pair of stacking devices whereby the pair of roller tracks extend at a lower elevation than the elevated feed conveyors, and a roller conveyor serving as a transfer conveyor, and rollers of which extend transversely of the rollers in the pair of roller tracks, the roller conveyor being arranged in between the inner adjacent ends of the pair of roller tracks;
b. a device for packing the stacks of single pieces in synthetic sheet or respectively in heat shrinkable thermoplastic sheet, the packing device mounted downstream of the transfer conveyor and including a frame, a pair of sheeting supply drums mutually spaced one above the other and adapted to form a vertical sheet curtain extending transversely of the feed direction of the stacks, a welding and severing device on the downstream side of the sheet curtain, a discharge conveyor and welding devices mounted on opposite sides of the discharge conveyor and adapted to seal the lateral open edges of a sheet sleeve wrapped around a stack;
c. a shrinkage tunnel having a separate discharge conveyor, both arranged downstream of the packing device;
d. a roller conveyor having driven rollers arranged downstream of the shrinkage tunnel with the discharge conveyor, a stacking device for stacking a stack on top of another stack, 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 stacks on the roller conveyor and adapted to be actuated by the stacks, the control devices coupled to drive means for raising and lowering the lifting platform;
e. 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 roller conveyor adjacent the stacking device, and transfer devices for the stacks whereby the roller tracks are mounted in carriage type frames movable by means of drive means transversely of the roller conveyor;
f. 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;
e. and whereby the drive means of the feed and discharge conveyors, of the devices for the compound stacking of the single pieces, of the stacking device for stacking a stack on top of another stack, of the 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 roller conveyor downstream of the shrinkage tunnel conveyor are coupled to control means for controlling the various movements, and the control means are combined in a program controller.
For alternately loading two containers, 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 roller conveyor along which the stacking devices are arranged 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.
A preferred illustrative embodiment of the present invention is shown in the appended drawing wherein
FIG. 1a, 1b and 1c are schematic view of the overall apparatus;
FIG. 2 is a top view of an independently operating device for the compound stacking of single pieces, and
FIG. 3 is a lateral elevational view of the device shown in FIG. 2.
The apparatus of the present invention comprises a pair of devices 10 and 10a for the compound stacking of the single pieces supplied such as sacks, a device 150 for packing the individual stacks in sheet material, a stacking device 115 for putting a stack S on top of another stack S, a transfer and storage conveyor 120 for alternately loading two containers C and a pair of container loading devices 130, 131.
As may be seen in FIG. 1b, the pair of stacking devices 10 and 10a are disposed opposite to each other and are mutually spaced. The two stacking devices 10, 10a are identical. In the following, only the stacking device 10 will be described. All parts of the device 10a corresponding to similar parts of the device 10 are designated by similar reference numerals with the appended letter "a."
The stacking device 10 comprises a feed conveyor 11 for feeding the single pieces. The feed conveyor 11 is mounted in a frame 12. Additional feed conveyors 13, 14 may be arranged upstream of the feed conveyor 11. These additional feed conveyors 13, 14 may serve to bring up the sacks from a filling station indicated at 15. The feed conveyor 11 then conveys the sacks into a zone in which the sacks may be transferred onto a discharge conveyor 16 which extends at a lower elevation than the feed conveyor 11. By means of a guide 17 consisting of a swingable plate and an abutment pin 18 disposed above the feed conveyor 11 the sacks may be rotated as required for the compound stacking (FIG. 2). The sacks then enter a space defined on one side by a rear abutment bar 20 which extends parallel to a return roller of the feed conveyor 11. Within this space, the sacks are made ready for the transfer onto a packing plate 22.
A transfer bar 21 extending parallel to the direction of movement of the feed conveyor 11 serves to transfer a layer of sacks onto a packing plate 22 disposed in the plane defined by the feed conveyor 11 and adjacent thereto. The packing plate 22 is located above a lifting platform 25. The size of the packing plate 22 corresponds approximately to the size of the lifting platform, and the packing plate has preferably a very small thickness, i.e., height. The packing plate 22 is movable in a direction parallel to the movement direction of the feed conveyor, and the lower surface of the packing plate is preferably curved outwardly from the edges towards the center of the lower surface.
The lifting platform 25 may be raised and lowered whereby during this movement the lifting platform is guided in lateral guides 26 of the base frame 19. The overall arrangement is such that when withdrawing the packing plate 22 from below a layer of sacks the sacks may be transferred onto the lifting platform 25 without undergoing any substantial deformation (FIG. 3). After loading with sacks, the lifting platform 25 is lowered by a distance corresponding to the height of one sack layer thus providing sufficient clearance for the next following sack layer and allowing to return the packing plate 22 into its loading position. To obtain a more compact stacking, every sack layer is pressed against the lower surface of the packing plate 22 which has been returned into its discharge position, by raising the platform 25 together with the sack layers already deposited thereon, and the sack layer is held in this condition until the packing plate 22 is again withdrawn.
The movements of the packing plate 22 and the lifting platform 25 are preferably coordinated in such a fashion that after withdrawing the packing plate 22 the lifting platform 25 is lowered by a distance corresponding to the height of the sack layer which has just been deposited thereon. Then the packing plate is returned into its loading position. While a new sack layer which has been prepared in the meantime is pushed by means of the transfer bar 21 onto the packing plate 22, the lifting platform 25 is raised, in pressing the uppermost sack layer thereon against the downwardly bulging surface at the bottom of the packing plate 22 and thereby deforming the upper surface defined by the sack layer resting on the platform. Then the packing plate is withdrawn, and the newly formed sack layer transferred onto the lifting platform 25.
The packing device 150 which will be described further below and a roller conveyor 110 having the stacking device 115 adjacent thereto are arranged downstream of the transfer conveyor 152. A device 115 for stacking two stacks S one on top of another is arranged adjacent the roller conveyor 110 and comprises a frame 116 with a lifting platform 117 which may be raised or lowered by means of a drive motor 119. The free end 117a of the lifting platform 117 facing the roller conveyor 110 is provided with lifting forks 117b adapted to be lowered between the rollers 111 of the roller conveyor 110 so that in the lower position of the lifting platform 117 the lifting forks are interposed between the rollers 111 of the roller conveyor 110. A stack S which has been moved into a position overlaying the lifting forks 117b will be lifted off the roller conveyor 110 when raising the lifting platform 117. The stack is lifted by the lifting platform 117 into an elevated position in which the lifted stack S is elevated above a next following stack fed by the roller conveyor 110. Control devices 118, preferably in the form of light barriers on either side of the roller conveyor 110 and adapted to control the movement of the lifting platform 117 are mounted in the vicinity of the stacking device 115. These control devices 118 may be actuated by stacks S supplied by the roller conveyor 110 in the direction of the arrow x and are connected to the power drive 119 for raising and lowering the lifting platform 117. Sensing elements detecting the height of the stacks S supplied and transmitting this information to control means (not shown) coupled to the drive motor 119 of the lifting platform 117 for controlling the lifting position of the platform 117 may be arranged above the roller conveyor 110.
If it is desired to put several stacks one on top of another, several stacking devices 115 may be arranged adjacent the roller conveyor 110.
A transfer and storage conveyor 120 is arranged transversely of the roller conveyor 110 at the discharge end 110a thereof. By means of the transfer and storage conveyor 120 already assembled compound stacks G may be directed to the various containers on the one hand, and compound stacks G may be assembled into blocks B 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 120 consists of a pair of roller tracks 121, 122 mounted one behind the other with an intermediate spacing corresponding approximately to the width of the roller conveyor 110. The roller tracks 121, 122 with their driven rollers 123, 124 are mounted in carriage type frames 127, 128 which are movable on guide rails transversely of the roller conveyor 110 by means of drive means 127a, 128a. Transfer devices 125, 126 are arranged in the vicinity of the roller tracks 121, 122. 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 121, 122 there may also be provided other suitable means for transferring the compound stacks G onto the one or the other end of the transfer and storage conveyor 120. The roller conveyor 110 preferably extends into the clearance between the pair of roller tracks 121, 122. The rollers 123, 124 of the pair of roller tracks 121, 122 of the transfer and storage conveyor 120 are mounted in the movable carriage type frames 127, 128 in such a manner that the rollers 123, 124 may pass between the rollers 111 of the roller conveyor 110 when shifting the roller tracks 121, 122. Entrainment dogs (not shown) at the movable carriage type frame 127, 128 serve to take along the compound stacks G when moving the roller tracks 121, 122.
A pair of parallel and mutually spaced tilting frames 130, 131 is mounted such that the one ends of the tilting frames are opposite to outer end portions of a roller track 121 or 122 respectively of the pair of roller tracks so that stacks G resting on the roller tracks 121, 122 may be transferred onto these tilting frames 130, 131 by means of the transfer devices 125, 126. Instead of using the transfer devices 125, 126 for transferring the compound stacks G, the rollers 123, 124 of the roller tracks 121, 122 may be power-driven. The tilting frames 130, 131 are tiltably mounted in the vicinity of their mid portions in suitable bearing blocks 132, 133. The frame sections 130a, 131a of the frames 130, 131 facing the transfer and storage conveyor 120 are each provided with a roller track 135, 136 respectively, and the rollers 137, 138 in these roller tracks 135, 136 extend parallel to the rollers 123, 124 of the roller tracks 121, 122 of the transfer and storage conveyor 120 and the rollers 111 of the roller conveyor 110. The tilting frames 130, 131 are each connected, at the lower side of the section containing the roller track 135, 136 respectively, with a lifting device of which the lifting device 134 for the tilting frame 130 may be seen in the drawing (FIG. 1c). The roller tracks 135, 136 extend along about the front halves of the tilting frames 130, 131 respectively, i.e., those frame sections facing the transfer and storage conveyor 120. The rear halves of the tilting frames 130, 131, i.e., the frame sections 130b, 131b are arranged in the form of support plates 140, 141 for the containers C.
The device 150 for packing the stacks S in synthetic sheet consists of a frame 151 with the two feed tracks 16, 16a for feeding the packing goods in the direction of the arrows x 1 and x 2 respectively. A sheeting supply drum 154 is mounted in the upper portion of the frame 151, and another sheeting supply drum 155 is mounted in the lower portion of the frame 151. The sheeting F is guided by a corresponding number of deflector rollers in such a manner that a vertical sheeting wall is formed transversely of the feed direction of the stacks S. The packing goods are 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 125, 126. From the feed tracks 16, 16a the packing goods are transferred onto a discharge conveyor 157. A welding device 156 is mounted between the sheeting wall and the discharge conveyor 157. The welding device 156 comprises an upper welding jaw 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 156 is furthermore provided with a severing device such as a severing knife, a hot wire or the like by means of which the sheet sleeve M enveloping the packing good after welding may bex severed from the sheeting supply subsequently to the welding operation. Preferably the welding jaws of the welding device 156 are of a type producing a double weld. Severing of the sheet sleeve from the sheeting supply will then be effected intermediate these two welds.
Further welding devices 158, 159 are arranged on either side of the discharge conveyor 157. The additional welding devices are of a type similar to the welding device 156 and serve to seal the lateral open edges of the sheet sleeve enveloping the packing goods. If the packing sheet consists of a heat shrinkable thermoplastic synthetic sheeting, another feed conveyor 160 and a shrinkage tunnel 161 are arranged downstream of the discharge conveyor 157. This feed conveyor 160 is then followed, at its downstream side, by the roller conveyor 110.
The drive means of the feed and discharge conveyors 13, 14, 11, 11a, 16, 16a of the devices 10, 10a for the compound stacking of the single pieces, of the stacking device 115, of the movable roller tracks 121, 122 of the transfer and storage conveyor 120, of the tilting frames 130, 131 with the containers C thereon, of the transfer devices 125, 126 and of the rollers of the roller conveyor 110 are coupled to control means (not shown) for controlling the various movements, 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 sheet packing device 150 which is located upstream of the loading apparatus stacking device so that the entire packing and loading operation as well as the packing may be centrally controlled and performed in a fully automatic fashion.
The operation of the loading apparatus according to the present invention is as follows: The stacks packed in sheet material are supplied to the stacking device 115 by means of the roller conveyor 110. When actuating the control members 118, the respective stack S is lifted by the stacking device 115 and deposited on top of the next following stack in the series of stacks supplied. The control members 118 may also be coupled to a stepping mechanism (not shown) which controls the incremental feed of the stacks S and the raising and lowering of the lifting platform 117 of the stacking device 115. The compound stacks G are then transported by means of the roller conveyor 110 to the transfer and storage conveyor 120 and are moved by the latter towards the conveyor section opposite to the container which is to be loaded. The stacks G are then transferred by means of the transfer device 126 onto the roller track 136 of the tilting frame 131 and on this roller track 136 assembled into a block B which at the end of the assembling operation is of a size corresponding to the dimensions of the interior cargo space of the container C. During the stacking operation of the individual compound stacks G into a block B, the tilting frame 131 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 120 is shifted so that any further compound stacks G supplied may be transferred onto the roller track 135 of the tilting frame 130. After assembly of the block B on the roller track 136 the tilting frame 131 is tilted by means of the lifting device associated therewith, i.e., the roller track 136 with the block B of compound stacks G assembled thereon is lifted so that the block B is transferred by gravity into the container C. The tilting frame 130 is shown in this loading position in FIG. 1c of 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 since the single pieces assembled in stacks by means of the pair of stacking devices 10, 10a are alternately supplied to the packing device 150. By assembling the single pieces E into stacks S or compound stacks G 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. By the fact that the single stacks are wrapped or enveloped in plastic sheet material no pallets need to be employed. Single stacks having various sizes may likewise be assembled by means of the apparatus of the present invention in such a manner achieving an efficient utilization of the containers. The transfer and storage conveyor 120 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 stacks aside for assembling another block B by means of stacks of suitable sizes which block is then loaded into the second container. The various devices of the overall apparatus may also be combined in a single machine frame.
Having thus described the invention, it will be apparent that various modifications may be made to the invention without departing from the scope thereof as set forth in the claims appended hereto.