EP0160825B1

EP0160825B1 - High speed stacking and packaging apparatus

Info

Publication number: EP0160825B1
Application number: EP85103662A
Authority: EP
Inventors: Joseph A. Lynch
Original assignee: Nabisco Brands Inc
Current assignee: Nabisco Brands Inc
Priority date: 1984-04-12
Filing date: 1985-03-27
Publication date: 1988-03-09
Also published as: EP0160825A1; DE3561798D1; ATE32861T1; CA1241675A

Abstract

A product (4) stacking apparatus for high speed packing of packaged units which includes an infeed conveyor means (2), a vertically movable product elevator (4) immediately adjacent the infeed conveyor means, a product stacking means for periodically transferring product units from the infeed conveyor ot the elevator and an elevator moving means for moving the elevator downwardly between the transfer operation of the product stacking means to stack the product units in a predetermined number of layers and returning the elevator upwardly when the stack is pushed from the elevator. A second conveyor is positioned adjacent to the elevator at a height such that the surface of the second conveyor is essentially coplanar with the elevator when it is in the fully descended position. A pusher means (30) is also used in the present apparatus for sliding the stacked layers of product units from the elevator onto the second conveyor. The pusher means includes spaced product engaging members which move between the spaced vertical product supporting members of the elevator and a pusher actuating means for extending and retracting the pusher means.

Description

The present invention relates to product handling, and, in particular, to a high speed product stacking apparatus according to the pre-characterizing part of claim 1.
In the past, package and bag handling have been subject to many constraints preventing high speed packing, especially when the product is easily broken or damaged. For example, in the case of filled flexible bags, the flexible nature of the bag makes it susceptible to puncture and prevents handling by apparatus designed to pack rigid articles. Excessive droppage and/or severe bending or folding contributes to product destruction. Consequently, a high degree of control must be maintained over a flexible bag as it is conveyed to the casing station and as it is packed in the appropriate carton or case and this leading to the respective requirements in costs.
US―A―,641,735 shows an apparatus for packing flexible bags into cases by delivering them to a hopper having an accumulator chamber into which the bags are dropped one layer at a time; and by transferring the bags into a case when a case load is accumulated. This known stacking or packing apparatus would not be useful if the bags contained product which is easily broken when dropped.
Similarly, with respect to semi-rigid and rigid packages contained brittle or breakable product, caution must be taken to preclude breakage and waste. Specifically, high speed automated packing of bulk cartons is severely hampered because of the requirement for careful stacking and loading. The problems associated with packing semi-rigid packages are amplified when the product is food since time between packaging the product and delivering it to the marketplace is critical and breakage more seriously detracts from the quality of the product.
DE-A-1 810 954, from which the present invention starts in the pre-characterizing part of claim 1 shows a stacking apparatus for ceramic plates, tiles or the like which allows a continuous stacking or packing of the respective products, whereby a continuous incoming stream of products is transferred into an intermittent output stream of the stacked products. However, since the products handled in case of DE-A-1 810 954 are ceramic plates, tiles or the like, a high-speed stacking and packing is not possible, since then the danger of breakage of the plates will occur.
It is therefore an object of the present invention to overcome the problems indicated above and especially to provide a product stacking apparatus being capable of high-speed packing of packaged goods, especially breakable goods without any problems.
A product stacking apparatus according to the present invention includes, in combination, an infeed conveyor means, a vertically movable product elevator positioned adjacent the infeed conveyor means and a product stacking means for periodically transferring product units from the infeed conveyor means to the elevator. The elevator, which is composed of spaced vertical products supporting members extending upwardly from a transverse member and perpendicularly between said infeed conveyor means and the second conveyor, is connected for actuation to an elevator moving means which moves the elevator downwardly between transfer operations of the products stacking means so that the product units are stacked in a predetermined number of layers on the elevator.
In one embodiment of the present invention, the infeed conveyor means includes a belt conveyor, a receiving plate at the end of the belt conveyor and a product stop element positioned on the receiving plate to allow a predetermined number of product units to be fed on the receiving plate. The product stacking means pushes the predetermined number of product units from the receiving plate onto the top of the elevator.
A second conveyor is situated adjacent to the elevator at a height at which the top of the second conveyor is substantially coplanar with the top of the spaced vertical product supporting members when the elevator is in its lowest position. The combination apparatus of the invention also includes a pusher means for sliding the stacked layers of product units from the elevator onto the second conveyor along with a pusher actuating means for extending the pusher means when the elevator is fully loaded and in its lowest position so that the stacked load of product units is transferred onto the second conveyor. The pusher means includes vertically oriented product engaging members spaced from one another so that they are interspersed between the spaced vertical product supporting members of the elevator. When the pusher means is extended, the top of the spaced product engaging members provides a temporary product support for product units being transferred from the infeed conveyor means while the elevator is substantially below the surface of the infeed conveyor means.
Operation of the elevator moving means and the pusher actuating means is timed so that the elevator is moved upwardly after transference of the stacked load therefrom while the pusher means is being retracted, the spaced vertical product supporting members of the elevator means intercalated with the spaced product engaging members to receive the transferred product units from the top of the product engaging members during upward movement of the product supporting members. As a result of this cooperative operation, the product units are maintained essentially at a constant level so that the product experiences little or no dropping whatsoever.
The spaced vertical product supporting members of the elevator means and the spaced product engaging members of the pusher means are preferably wall elements which extend perpendicularly between the infeed conveyor means and the second conveyor. The vertical product supporting members, as well as the product engaging members, are spaced so that each of the product units in the first layer of product transferred from the receiving plate spans a plurality of such elements.
In one embodiment of the invention, the apparatus includes a frame means which supports a vertical rod at each end of the transverse member on which the elevator is slidably mounted. The elevator moving means includes a cam operated lever means for moving the elevator along the rods, so that it descends the required distance for adding another row of packaged product after receiving the previous row, and so that the elevator is driven up the rods at the appropriate time to receive the row of packaged product from the top of the pusher means as it is retracted from the extended pushing position.
Similarly, with respect to the pusher means, transverse means are provided for unifying the product engaging members, and the apparatus includes a horizontal rod mounted to the frame means at each end of the pusher means, and means for slidably mounting the pusher on the horizontal rods is also provided. The pusher actuating means also includes a cam operated lever means for moving the pusher along the horizontal rods.
In the preferred embodiment, both cam operated actuating means are driven by a common drive means which is actuated in response to the arrival of packages of product at the infeed conveyor means.
As a result of the present invention, a mechanical high speed stacking and packing apparatus is provided by which an essentially uninterrupted flow of fragile packaged goods can be stacked to any desired carton capacity and packed without fear of loss due to breakage.
For a better understanding of the present invention, together with other and further details, reference is made to the following description, taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a perspective view of an embodiment of the present invention during operation;
Fig. 2 is a rear elevation view of the apparatus of the present invention in operation with packages arriving from the opposite side of the approach shown in Fig. 1;
Fig. 3 is a side elevation of the apparatus of the present invention taken along lines 3―3 in Fig. 2; and
Fig. 4 is a side elevation which depicts the apparatus as it packs a carton while allowing for a continued stacking operation.

Referring to the drawings, there is seen in Fig. 1 a belt conveyor 2 delivering in the direction of arrow "a" product packages 4, which appear in the drawing as three rows of crackers and/or cookies per package. A receiving plate 6 is provided with a package stop element 8 at a distance sufficient to allow the desired number of product units to be fed onto the plate 6 at one time. In Fig. 1, the preferred number of packages is three.
A product stacking means is located in conjunction with the receiving plate 6, such as the sprocketed chain pushing combination 10 shown in Fig. 1. This product stacking means is depicted herein as a chain drive 16 which drives the chains 14 mounted thereon in the direction of circular arrow "b". Sprocketed tension wheels 12 are positioned opposite drive sprocket wheels 16 to provide the appropriate tension on chains 14. In order to transfer the predetermined number of product units from the receiving surface 6, pushing elements 18 are fixed to chain 14 by mounting brackets 17 at appropriate distances from each other so that a full complement of product units, shown herein as three packages, will be positioned on receiving plate 6 before they are pushed therefrom by pushing elements 18. The timing required to effect transfer of the desired number of units from the receiving plate 6 to the elevating means, or the top of product engaging members 32, can be provided with indexing units of devices which are commercially available. In one embodiment of the invention, it has been found that a convenient cycle includes 1/3 movement time and 2^/3 resting time per cycle.
A preferred embodiment of the present invention also includes a product detection switch fixed on stop element 8 which, when engaged by a package unit, is retracted to facilitate easy transfer of the product units from the receiving plate 6.
Immediately adjacent the receiving plate 6 is located a vertically movable product elevator 20 composed of spaced vertical product supporting members 22 which, in the preferred embodiment, are wall members extending upwardly from a transverse member 24. In its highest position, the top of the spaced vertical product supporting members 24 are essentially coplanar with the surface of the receiving plate 6 or are just immediately therebelow so that the product units 4 will slide easily from the receiving plate to the top of the elevator without dropping a distance which would cause the contents to break. Moreover, the vertical product supporting members are spaced so that each product unit in the first layer of product units on the elevator spans a plurality of such members, which, in one embodiment includes three supporting members.
After a row of product units are transferred from the receiving plate 6 to the top of vertical support members 20, the elevator is moved downwardly, either by a timing mechanism which actuates an elevator moving means or by the weight of the product, to a position in which the last row of transferred product unit forms the receiving surface for the next row of product units such as packages 4. In a preferred embodiment, the timing required to lower the elevator means after deposition of a row of packages can be achieved by an irregularly-shaped cam means 40, driven by common drive shaft 60, which operates cooperatively with cam follower 44 and linking arms 41, 42 and 43. When the elevator has descended to its lowermost position, the preselected amount of rows of unit product for packing a carton or crate has been stacked thereon. The direction of the reciprocating elevator movement is indicated by arrow "c" in Fig. 1.
In order to effect packing of the stacked units of product into the shipping carton 50, the present invention includes a pusher means 30 in combination with a pusher actuating means having spaced product engaging members 32 which move between the spaced vertical product supporting members 22 when the actuating means is extended to push the stacked packages from elevator 20 into the carton 50 shown here on belt conveyor 100. When the pusher means is fully extended, the top of product engaging members 32 is located substantially coplanar with the surface of receiving plate 6 or just below such surface so that the process of article transfer from receiving plate 6 can continue without interruption. See Fig. 4.
Just as with the vertical product supporting members of the elevator, the product engaging members are spaced from one another so that each product unit in the first layer of product units transferred from the receiving plate 6 spans a plurality of the engaging members. When the full complement of stacked packages have been pushed from the elevator 20 into cartons 50, the elevator is moved upwardly by the elevator moving means, the vertical product supporting members spaced so that they are interspersed between product engaging members 32, simultaneously with the retraction of the pusher means 30, whereby the row of transferred product units are gently received on the product supporting members 22 without severely changing the horizontal plane of support of the product units during the combination elevator-ascending and pusher-means- retracting movement. A minor drop of no more than about 1/2" can be tolerated without undue breakage.
Meanwhile, conveyor 100 moves in a direction of arrow "e" shown in Fig. 1 to advance the packed carton on towards sealing and loading and introduces a new empty carton for packing. The direction of movement of the pushing means 30 is shown by arrow "d" in Fig. 1.
Referring to Figs. 2 and 3, there is depicted a rear elevational view and a side elevational section view taken along line 3-3 in Fig. 2, respectively. Relative to the elevator, there is shown transverse member 24 from which vertical product supporting members 22 extend upwardly. The apparatus is shown as further including frame means 28 at either end of the elevator to which a vertical rod 27 is attached by means of brackets 25 to provide a supported vertical track on which the elevator is slidably mounted via slidable mounting means 23.
The elevator is controlled by an elevator moving means which includes a cam-operated lever means defined generally by interconnected linking arms 41, 42, and 43, and cam follower 44. The lever means is operated by rotation of cam 40, which is driven by common drive means 60, against cam follower 44 attached to the far end of lever element 42.
Turning now to the pusher means 30, there are shown transverse unifying means 35 which stabilize the product engaging members 32 relative to each other, and a horizontal rod 31 extending essentially from front to rear of the apparatus and mounted on frame member 28 via mounting brackets 33. Slidable mounting member 37 connects pusher means 30 for movement back and forth on rod 31. A second cam operated lever means includes linking rod members 45, 46, 47, and 48 which connect mounting member 37 to the cammed operation provided by cam groove 61, which is cut in the surface of wheel 62, in combination with cam follower 49. In the embodiment shown in Fig. 3, the cam groove 61 is shown as having a generally circular path. However, in order to provide the appropriate timing for applicafion to specific cases, it is contemplated that the cam path can have any configuration suitable for the task. Further, as in the case of the cam 40, the wheel 62 can be driven by drive shaft 60.
While these embodiments show one configuration of mechanical means for operating the apparatus of the present invention, other configurations of mechanical parts and operation can be used, and it is not intended to limit the apparatus and operation of the present invention to those embodiments shown and described herein.

Claims

1. A product stacking apparatus comprising: infeed conveyor means (2), a vertically movable product elevator (20) positioned adjacent said infeed conveyor means (2) and including at least one vertical product supporting member (22) having a top surface substantially coplanar with the surface of said infeed conveyor means (2) when said elevator (20) is in the fully ascended position, elevator moving means (41, 42, 43, 44) for moving said elevator downwardly between transfer operations to stack product units (4) in a predetermined number of layers and returning said elevator to the fully ascended position when said stack is pushed from said elevator, a second conveyor (100) adjacent to said elevator (20) at a height in which the surface of said second conveyor (100) is essentially coplanar with the top surface of said vertical product supporting member (22) when said elevator (20) is in the fully descended position, pusher means (30) for sliding the stacked layers of product units (4) from said elevator (20) onto said second conveyor (100) including spaced product engaging members (32), and pusher activating means (45, 46, 47, 48) for extending and retracting said pusher means (30) characterized in that

said supporting member (22) comprises wall members extending perpendicularly between said infeed conveyor means (2) and said second conveyor (100); and

said wall members are spaced so that each product unit in the first layer of product units on the elevator (20) spans a plurality of said wall members.

2. Apparatus according to claim 1, wherein said infeed conveyor means (2) includes a belt conveyor, a receiving plate (6) at the end of said belt ccnveyor, and a product stop element (8) to allow a predetermined number of product units to be positioned on said receiving plate (6), and wherein a product stacking means (18) pushes said predetermined number of product units from said receiving plate (6) onto said elevator (20).

3. Apparatus according to claim 1, wherein said elevator (20) includes transverse member means (24) from which said wall members (22) extend upwardly, said apparatus including frame means (28) at each end of said transverse member means (24), a vertical rod (27) mounted to each frame means, means (23, 25) for slidably mounting said elevator on said rods, and cam operated lever means for moving said elevator along said rods.

4. Apparatus according to claim 1, wherein said pusher means (30) includes transverse means (35) for unifying said product engaging members, said apparatus including a horizontal rod (31) mounted to each frame means, means (37) for slidably mounting said pusher on said horizontal rods, and second cam operated lever means for moving said pusher means along said horizontal rods.