GB2099928A - Unloading containers - Google Patents

Abstract

Unloading of tubular containers (23) is by way of a container-entrant plunger assembly (49) to express those contents via an inner tube (52) registering with a piercing of one end of the container. Peripheral severing of that end of the container allows a shape-rectifying size of plunger to be used and carry with it the severed container end. Fluid passages through the plunger head enable forced flow of fluid against or along inner walls of the container. Piercing and severing of the container end takes place at a separate station (30A) via a piercer (41) and cutter (42). All operations are shown from below and there are feed means to, from and between stations relative to a conveyor. <IMAGE>

Description

SPECIFICATION Unloading containers The invention relates to unloading tubular containers, for example so-called tins or cans, particularly, but not necessarily exclusively, when loaded with fairly solid, perhaps paste-like, materials such as vegetable pulp.

A need arises in the food industry for speedy and efficient unloading of vegetable pulp containers in order to use their contents in making up other food products, for example tomato pulp for use in making soups and other food products. A characteristic feature of such pulp materials is that they tend to cling to the sides of the container and may not readily break up under suction to allow normal ingress of air to avoid formation of a vacuum when attempting to suck out the contents. Substantial waste is inevitable by leaving material in the containers, especially if such containers are buckled or deformed in any way as often happens with tins or cans.

Whilst it is an object of this invention to reduce or eliminate one or more of such problems, it is equally not intended necessarily to limit application of embodiments of the invention to vegetable pulp materials nor even to other materials having the aforesaid characteristic feature.

According to this invention loaded containers have their contents removed by a container-entrant means with associated forced flow into the container of a fluid.

Suitable container-entrant means comprise a plunger, preferably one that is of an effective size little less than the cross-section of the container.

Normally, that plunger will further include or be part of, material take-off means fed automatically with material expressed by action of the plunger. A specific advantageous plunger assembly has a tubular part within its overall cross-section as said material take-off means. Moreover, it is preferred that the plunger assembly engage and cooperate with an end of the container that is pierced in registration with access to the material take-off means, and severed, usually peripherally just inside the container side walling, to itself enter the container during plunger operation.

Piercing and severing of the container end will clearly be done prior to plunger operation in expressing container contents, and is conveniently done at a separate station of overall apparatus, and from below, at least where neither the severed end nor the material contents can be lost or detached in moving between stations.

In orderto service buckled or otherwise deformed containers, it is advantageous for the plunger assembly to have, over at least a substantial end part thereof, a cross-sectional size matching or nearly matching the container itself. For the preferred severed end of the container, that ensures full support thereof in forcibly restoring the container towards its nominal tubular shape without jamming resulting from deformation of the severed container end.

Clearly, however, removal of such a size of plunger assembly may be rendered difficult by a tendency to create a vacuum, at least if the material take-off means does not allow ingress of air, which may be undesirable for reasons related to the removed contents or the preferred manner of operation of the take-off means. The aforementioned forced flow of fluid into the container will assist such removal of the plunger assembly when made after expression of the container contents.

However, forced supply of fluid into the container even while the plunger is operative to express the container contents has also been found to be advantageous in promoting cleaner removal of the container contents, especially when, as is preferred, that supply of fluid is substantially peripheral of the plunger assembly.

It will be appreciated that the fluid may be whatever suits the container contents, water being convenient wherever the contents are to be so diluted.

Plunger apparatus embodying this invention comprises a double-walled tubular plunger of which an inner tube constitutes the take-off means and an outer tube receives said fluid for escape through apertures in an annular disc closing the outer tube at its container-entrant end.

A preferred overall apparatus hereof comprises a conveyor for containers, the conveyor passing to one side of two spaced stations, one having means to pierce and sever a container end the other having a contents - expressing - plunger, and transfer means successively operable to pass a loaded container from a first position on the conveyor to said one station, to pass that container with its end pierced and severed from said one to said other station, and to pass the unloaded container from said other station to a second position on the conveyor downstream of said first position.

A preferred overall apparatus hereof has a lower table surface through which container end piercing and severing means, and plunger unloading means, are operative on containers standing on one of their ends on that surface with their other end below another surface restraining the containers against upward displacements.

Practical implementation of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure lisa plan view on lines A-A of Figures 2 and3; Figure 2 is an end view; and Figure 3 is a part-sectional view on lines B-B of Figure 1.

In the drawings, container unloading apparatus 10 comprises a substantially cuboid body 11 supported on legs 12 at its corners, and fabricated from metal plates. Medially, actually substantially centrally, the body 11 has an upwardly open channel 13 between its ends. A conveyor 14, conveniently of endless track type, is accommodated in the channel 13 with its upper surfaces substantially level with top surface 16 of the body 11. The conveyor 14 can, of course, have its return run in the channel 13 as shown, and will normally extend between loading and unloading stations 18, 19 beyond respective ends of the body 11.

Above the top surface 16 of the body 11 is a plate 21 carried by studs 22 at a spacing above the top surface that is a desired clearance relative to nominal heights of containers 23, actually indicated as tins with rim-secured slightly inset ends 23A, 23B.

The bodytop isapertured at30,31 associated, with container end-piercing/severing and contentsunloading stations 30A, 31 A respectively. Those stations and apertures are both to the same side ofthe conveyor 14. A U-shaped container traverse channel (from and back to the conveyor 14 through the stations 30A, 31 A) is defined by inner guides 32A, 32B, 32C and outer guides 33A, 33B, 33C. Rams 34,35,36 with containerengaging ends 34A, 35A and 36A are shown operative to transfer containers from the conveyor 14 to the end piercing/severing station 30A, between the stations 30A and 31A, and from the unloading station 31A back to the conveyor, respectively.The inner guide 32A actually extends over the conveyor 14 to stop containers thereat.

The piercing/severing station 30A has a pressure fluid actuation device 39 for a combined piercer and cutter head on axially reciprocable shaft 40. A central piercer 41 is tapered to a point for easy puncture of the container end and extends above a crown-like toothed blade 42 for severing container ends at or near their peripheral connection with side-walling 45 ofthe container.

In practice, the piercer and cutter head acts on the container against the upper plate 21 and accurate location will not be disturbed once piercing is under way. Thus, the ram 34 may be retracted at that time, i.e. before severing.

Pulp or paste-like contents of the containers will assurethatthe severed container end is held on by contact with the contents themselves. The ram 35 is then actuated to bring the container to the unloading station 31A.

The unloading station 31A has a plunger assembly 49 comprising an annular head 50 over space 51 between inner and outerwalls52, 53 of a doublewalled tubular plunger of an overall cross-section that is but a close clearance on the inside of a con tainerto be unloaded. The plunger assembly 49 is axially reciprocable in spaced bearing 54, 55 suitably carried in spaced annular plates 56, 57 and covers 58, 59 secured by studs 60 to the underside of the top plate ofthe body 11.

The other end of the space 51 is closed by a necked plate 61 through which the inner tube wall 52 passes for container contents take-off purposes. There is a tubular connection spigot 63 through the plate 61 to the space 51 and a series of peripherally spaced holes 64 from the space 56 through the chamfered top edge portion 65 of the plunger head 50.

The plate 61, and thus the piston assembly 49, is fixed relative to studs 65 that pass through the bear ing plates 56, 57, the top plate of the body 11, and the upper plate 21 to a cross head 66 forming a yoke by which the plunger assembly is reciprocable. Such reciprocation is effected by a piston rod 67 of an actuator ram 68 mounted on a plate 69 fixed to upward extensions of the adjacent studs 22A.

In operation, the unloading station 31A will have its plunger head engage the pierced and severed container end with inner, material take-off, tube 52 in registration with its piercing. Operation of the actuator ram 68 will raise the plunger assembly 49 and forced the severed container end up the con tainerto express its contents down the take-off tube 52, which will be connected to any convenient utilisation or bulk storage system.

At least at the end of that upward stroke of, but preferably also during, that upward stroke of the plunger assembly 49 fluid will be supplied under pressure to the space 51 to aid the downward retraction, stroke of the plunger assembly 49, preferably also container scouring during the upward expression stroke.

Using water as the fluid, we find that a fairly low pressure, corresponding to mains supply is adequate, and the pressure required for the expression stroke of the plunger assembly, at least when such water pressure is applied, is quite light, say about30 psi for a two inch hole in a 6 inch diameter can 92 inches high for tomato pulp.

It will be appreciated that apparatus embodying this invention need not necessarily be arranged to pierce, sever and unload containers from below, and that others transport and transfer systems and layouts could be used.

Particular variants and modifications envisaged include application of vacuum to the unloading tube 52 in order to assist removal of can contents and/or their subsequent transfer to storage and/or util isa- tion stations.

Also, there is some risk of spillage at the piercing and severing station 30A, which can collect on the operating device 39. That can be avoided by having that device 39 our a functional equavalenttherefor sited above the cutting and severing head 41,42, say operative in a mount similar two the plunger assembly of the unloading station 31A. Then drip collection means, for example trays, can be used at least at the piercing and severing station.

Moreover a fastener container feed system could include an indexing screw or rotary indexing table with an appropriate disposition of the unloading and piercing/severing stations.

Claims (23)

1. Method of unloading tubular containers wherein contents are expressed by container entrant means due to pressure exerted by such means and there is forced flow of a fluid into said container at least for container cleaning purposes.

2. Method according to claim 1, wherein the forced fluid flow accompanies entry of said means into the container and is substantially peripheral of the container interior to aid clean expression of contents.

3. Method according to claim 1 or claim 2, wherein normal cross-sectional dimensions of the containers are physically supported by said means when entrant into the containers.

4. Method according to any preceding claim, wherein each of closed containers is first pierced at one end to mate with an extractor tube of said means and is then cut and severed substantially peripherally at the same end whereafterthe severed end is itself pressed down into the container during expression of its contents, said forced fluid being at the peripheral edge of said severed end.

5. A method according to claim 4, wherein the container is moved between a piercing and endsevering station and a material expression station.

6. Apparatus for unloading tubular containers, comprising a plunger for entering a said container from one end in order to express its contents by the action of the plunger and means for applying a forced flow of fluid substantially against the inner wall of that container.

7. Apparatus according to claim 6, wherein the plunger has within its cross-sectional extent a tubular part serving for take-off of the container contents, said tubular part, in operation, registering with a piercing of said one end of said container.

8. Apparatus according to claim 6 or claim 7, wherein the plunger, in operation, serves to engage said one end of said container, which end is severed substantially peripherally, and to force that end into the container during plunger action to express contents of the container.

9. Apparatus according to claim 6,7 or 8, wherein the plunger has a head apertured to pass said fluid supplied thereto, preferably from a chamber within the plunger.

10. Apparatus according to claim 9 with claim 7, wherein said tubular part is within a said chamber.

11. Apparatus according to claim 10 wherein said tubular part and said chamber are concentric within an elongate double-walled tubular plunger body.

12. Apparatus according to any one of claims 6 to 11, comprising means for piercing said one end of said container at a contents take-off position, and means for severing said one end of said container substantially peripherally.

13. Apparatus according to claim 12, wherein the means of claim 12 are at a first station separate from a second station for means of any one of claims 6 to 11.

14. Apparatus according to claim 13, comprising first feed means for moving containers between the first and second stations.

15. Apparatus according to claim 14, comprising second feed means for supplying containers one by one to the first station.

16. Apparatus according to claim 14 or 15, comprising third feed means for removing emptied containers one by one from the second station.

17. Apparatus according to claim 15 or 16, wherein the or each feed means is operative relative to a moving conveyor for the containers.

18. Apparatus according to claim 17, wherein the second and third feed means operate transversely of the same said first conveyor with which is associated a stop for the containers between off-loading and on-loading positions for the second and third means, respectively.

19. Apparatus according to any one of claims 14 to 18, wherein the or each feed means comprises guide-and-ram means.

20. Apparatus according to any one of claims 6 to 19, wherein the said containers are operated upon from a downwardly directed said one end.

21. Apparatus according to any one of claims 6 to 20 wherein expression of contents is accompanying by rectification of any deformation of container side walls by reason of the entrant plunger substantially matching the cross-section of the container interior.

22. Method of unloading tubular containers substantially as herein described with reference to the accompanying drawings.

23. Apparatus for unloading tubular containers arranged and adapted to operate substantially as herein described with reference to and as shown in the accompanying drawings.