Apparatus for cleaning inside and outside surfaces of containers

Abstract

Apparatus for cleaning open-mouthed cylindrical containers has a plurality of pot assemblies mounted on a turntable rotatable to move each pot assembly past an unloading station for discharge of containers from the pot assemblies and a loading station for insertion of containers into the pot assemblies. Each pot assembly comprises a body co-operating with a lid to define a cavity for reception of a container, the cavity having a shape corresponding approximately to that of the container and having a size such that the container subdivides the cavity into two chambers in which the walls of the cavity are spaced close to the inside and outside surfaces of the container. Cam rollers on each pot assembly co-operate with cam tracks, upon rotation of the turntable, to open the lid immediately prior to passage past the unloading station and to close the lid immediately after passage past the loading station. During passage between the loading and unloading stations cleaning liquid is circulated through the chambers, the liquid flowing along the inside and outside surface of the container to clean the surfaces. The liquid flows at high speed due to the small volume of the chambers. Rinsing water is then circulated through the chambers, and finally drying fluid to dry the container before discharge at the unloading station.

Description

This invention relates to the cleaning of containers or jars, and is concerned more particularly but not exclusively to the cleaning of open-mouthed metal containers of the kind comprising a cylindrical body open at one end and closed at the other end by a circular disc which may either be flat or contoured to provide resistance to internal pressure.

Metal containers of this kind are commonly used for the packing of aerated beverages and they are often made by drawing in a single piece. The action of drawing involves the use of lubricants which have to be completely removed before such containers can be used for food packaging or be satisfactorily printed on the outside for display purposes.

It is normal practice for such containers to be cleaned by placing them on a conveyor and subjecting them to high pressure sprays of detergent water followed by sprays of washing water, followed by a period of draining and drying by means of hot air circulation.

When such containers are made from aluminium it is sometimes desirable to includeswifth width of the chambers, travels at a fast speed across all the surfaces of the container. The screw thread on the walls of the core and shell cause turbulence in the liquid and thereby ensure the maximum cleaning effect on the surfaces of the container. Instead of providing screw threads on the core and shell, these parts may be shot blasted or otherwise roughened so as to cause turbulence in the liquid. Alternatively, air may be introduced into the liquid, conveniently in the feed pipe to the pump for the liquid, to form bubbles which will cause turbulence in the liquid in the chambers.

Rinsing water will flow through the two chambers when the ducts 120, 121 register with the grooves 127a, 127b in the distributor ring, and hot air will flow through the two chambers to dry the container when the ducts 120, 121 register with the grooves 128a, 128b. The lid then opens as the pot assembly travels past the cam blocks 106, 112. When the pot assembly arrives at the unloading station the duct 121 registers with the groove 129 in the distributor ring and compressed air from the groove 129 enters the inner chamber and ejects the container from the pot assembly and into the unloading mechanism.

If any of the pot assemblies is not loaded with a container at the loading station, the valve 73 will remain engaged against the wall 75 and prevent entry into the cavity of the cleaning or rinsing fluids.

When the lid is closed on each pot assembly its lip 64 clamps the cylindrical wall 68 of the resilient sealing member against the convex surface 56 on the shell to provide a fluid tight fit. Moreover, since the wall 68 projects below the lip, fluid pressure in the outer chamber forces the wall 68 against the convex surface to provide an additional safeguard against leakage of liquid.

The apparatus described above is particularly suitable for use in cleaning containers with trichlorethylene or other highly toxic liquids or vapours, since the cleaning fluid flows in closed circuits.

FIGS. 8, 9, 10 show alternative constructions of pot assmblies assemblies which could replace the pot assemblies 38 in apparatus adapted to accommodate them, and like parts are indicated by like reference numerals.

The pot assembly of FIG. 8 has an outer shell 158 138 formed integral with the cover plate 60 of the lid, the bottom of the shell being open so that the inner and outer chambers formed between a container and the shell and core are open at the bottom. The container rests on the ledges 55 on the centering ring, as in the pot assembly 38, but the lid is provided with pins 140 which project into the cavity and which are adapted to engage a container therein to space lid from the top of the container. In operation, cleaning liquid is supplied to the outer and inner chambers through the pipe 30 and duct 50 and escapes through the openings at the bottom of the chambers.

The pot assembly of FIG. 9 is similar to that of FIG. 8, except that a seal 141 is provided between the bottom of the shell and the support plate 36. Cleaning liquid supplied through either the pipe 30 or duct 50 flows in succession through the two chambers, as in the pot assembly 38, and exhaust through the duct 50 or pipe 30 respectively.

The pot assembly of FIG. 10 has a shell and core similar to that of the pot assembly 38, but is provided with exhaust ducts 142, 143 at the bottom of the cavity so that cleaning liquid can be fed simultaneously through the pipe 30 and duct 50 into the two chambers formed between a container and the core and shell. The lid is spaced from a container in the cavity by pins 140 and an O ring seal 144 is provided between the cover plate 60 of the lid and the top of the shell.

Claims

1. Apparatus for cleaning an open-mouthed container of a given size, comprising at least one pot assembly having a core, a shell and a lid defining a cavity for reception of the container, the cavity having walls and the lid being movable into an open position to permit introduction of the container into the cavity; container centering means in form of a plurality of fins on at least one of said walls of said cavity, said fins having chamfered ends adapted to engage the mouth of the container in the cavity and the cavity having a shape corresponding approximately to that of the container and a size such that the container subdivides the cavity into two chambers in which the walls of the cavity are spaced close to the inside and outside surfaces of the container; and conduit means for passing cleaning fluid through said chambers so that the cleaning fluid fills the chambers and flows along the inside and outside surface of the container.

2. Apparatus as claimed in claim 1, wherein at least part of one wall of the cavity has a rough surface adapted to cause turbulence in fluid flowing through the chambers.

3. Apparatus as claimed in claim 2, wherein at least part of one wall of the cavity has grooves providing said rough surface.

4. Apparatus as claimed in claim 1, wherein the cleaning fluid is a cleaning liquid, and including means operable to introduce air into the cleaning liquid in said conduit means so as to form bubbles in the liquid.

5. Apparatus as claimed in claim 1, wherein the fins are provided with ledges adapted to engage the mouth of the container in the cavity and support the container therein.

6. Apparatus for cleaning open-mouthed containers of a given size, the apparatus comprising a frame; a turret rotatably mounted on said frame; a plurality of pot assemblies supported on the turret, each pot assembly having a core, a shell, and a lid co-operating with said core and shell to define a cavity for reception of one of said containers and said cavity having at least one wall; means for centering the container in the cavity, the cavity having a shape corresponding approximately to that of the container and a size such that the container therein subdivides the cavity into two chambers in which the wall of the cavity is spaced close to the inside and outside surface of the container, and conduit means for passing cleaning fluid through said chambers so that the cleaning fluid fills the chambers and flows along the inside and outside surfaces of the container, drive means operable to rotate the turret so that each pot assembly passes in succession past a container unloading station and a container loading station, lid control means operable to move the lid of each pot assembly into an open position immediately prior to passage of the pot assembly past said unloading station to permit ejection of a cleaned container at said unloading station and introduction of a container to be cleaned into the cavity of the pot assembly at said loading station, said lid control means also being operable to move the lid of each pot assembly into a closed position immediately after passage of the pot assembly past said loading station, and valve means for regulating flow of fluid through said conduit means and chambers only during passage of each pot assembly between said loading station and said unloading station.

7. Apparatus as claimed in claim 6, including means for extracting air from the cavity in each pot assembly in register with the container loading station, so that a container inserted into the cavity will be drawn to the bottom of the cavity by suction.

8. Apparatus as claimed in claim 6 including means for supplying compressed air to the cavity in each pot assembly in register with the container unloading station to eject a container therefrom.

9. Apparatus as claimed in claim 6, wherein the lid of each pot assembly is connected to a shaft movable axially and rotationally by cam means to displace the lid between its closed and open positions.

10. Apparatus as claimed in claim 9, wherein the lid is connected to a sleeve mounted on said shaft, said sleeve and shaft having co-operating abutments thereon, and a spring biases the sleeve in a direction to engage said abutments with one another, said sleeve being movable in the opposite direction against the action of the spring to move the lid in a direction away from the core of the pot assembly.

11. Apparatus as claimed in claim 10, wherein said abutments have surfaces thereon in frictional sliding contact for transmitting torque between the shaft and sleeve.

12. Apparatus as claimed in claim 10 and including alignment means adapted to prevent the lid being moved into the closed position except when the lid is at a predetermined angular setting relative to said shaft.

13. Apparatus as claimed in claim 12, including abutments adapted to engage the lid at opposite ends of its arcuate movement under the action of said cam means when the lid is in said predetermined angular setting relative to the shaft.

14. Apparatus as claimed in claim 12, wherein said shaft is mounted in a bush, said sleeve is formed with teeth and said bush is formed with recesses engageable with said teeth when the lid is in the closed position, said teeth and recesses constituting said alignment means.

15. Apparatus as claimed in claim 9, wherein said shaft is parallel to the axis of the core of the pot assembly, said cam means comprise first and second followers connected to said shaft for movement therewith, and said frame is provided with first and second tracks for co-operation with said first and second cam followers respectively, the first cam follower being movable under the influence of the first cam track during rotation of the turret to effect axial movement of the shaft and thereby displace the lid axially relative to the core of the pot assembly, and the second cam follower being movable under the influence of the second cam track during rotation of the turret to effect angular movement of the shaft and thereby swing the lid in direction transverse to the axis of the core of the pot assembly.

16. Apparatus as claimed in claim 15, wherein said first track extends only part-way around the frame and is arranged to engage the first cam follower only during the period in the rotation of the turret in which the lid is substantially aligned axially with the core of the pot assembly.

17. Apparatus as claimed in claim 6, wherein each pot assembly is provided with valve means preventing entry of fluid into the cavity when empty of a container, and actuating means operable to open the valve means in response to insertion of a container in the cavity and closure of the lid on the cavity.

18. Apparatus as claimed in claim 17, wherein the valve means comprises a closure member mounted in an inlet duct in the lid, the closure member being biased by a spring against a valve seat, and the actuating means comprises a stem on the closure member extending across the cavity when the valve is in the closed position.

19. Apparatus as claimed in claim 6, wherein the spacing between the core and shell is not greater than 0.15 inches, preferably 0.015 inches.

20. Apparatus as claimed in claim 6, wherein the lid is formed integral with the shell.

21. Apparatus as claimed in claim 6, wherein the core of each pot assembly is provided with duct means for introducing the cleaning fluid into the inner chamber formed between the core and the inside surface of the container in the pot assembly, and said centering means comprises abutments on the lid adapted to engage the base of the container forced towards the lid by the pressure of fluid in said inner chamber.

22. Apparatus as claimed in claim 21, wherein said abutments consist of pins mounted in the lid and projecting into the cavity in the pot assembly.

23. Apparatus as claimed in claim 21, wherein said centering means also comprise a plurality of fins on the wall of the cavity, the fins having chamfered ends adapted to engage the mouth of a container in the cavity.

24. An apparatus as claimed in claim 6, wherein the means for centering the container comprises a plurality of fins on the wall of the cavity, the fins having chamfered ends adapted to engage the mouth of the container in the cavity.

25. Apparatus as claimed in claim 6, wherein at least part of one wall of the cavity has a rough surface adapted to cause turbulence in fluid flowing through the chambers.

26. Apparatus as claimed in claim 25, wherein at least part of one wall of the cavity has grooves providing said rough surface.

27. Apparatus as claimed in claim 6, wherein the cleaning fluid is a cleaning liquid, and including means operable to introduce air into the cleaning liquid in said conduit means so as to form bubbles in the liquid.

28. Apparatus for cleaning open-mouthed containers of a given size, the apparatus comprising a frame; a turret rotatably mounted on said frame; a plurality of pot assemblies supported on the turret, each pot assembly having a core, a shell, and a lid co-operating with said core and shell to define a cavity for reception of one of said containers and said cavity having at least one wall, the cavity having a shape corresponding approximately to that of the container and a size such that the container therein subdivides the cavity into two chambers in which the wall of the cavity is spaced close to the inside and outside surface of the container, and conduit means for passing cleaning fluid through said chambers so that the cleaning fluid fills the chambers and flows along the inside and outside surfaces of the container, drive means operable to rotate the turret so that each pot assembly passes in succession past a container unloading station and a container loading station, lid control means operable to move the lid of each pot assembly into an open position immediately prior to passage of the pot assembly past said unloading station to permit ejection of a cleaned container at said unloading station and introduction of a container to be cleaned into the cavity of the pot assembly at said loading station, said lid control means also being operable to move the lid of each pot assembly into a closed position immediately after passage of the pot assembly past said loading station, and valve means for regulating flow of fluid through said conduit means and chambers only during passage of each pot assembly between said loading station and said unloading station.