GB2283410A - Washing articles on a conveyor - Google Patents

Abstract

Apparatus for washing articles, such as machine components, plastics extrusions, mouldings and such like includes a conveying means 13 upon which the articles are placed and which passes through at least a washing station 11 and typically also a drying station 12, and at least one duct 17 having nozzles through which the fluid is passed onto the articles, at least one of the ducts extending along the line of travel of the articles. This allows the overall size of the machine to be reduced without adversely affecting the quality of wash. In a further aspect the speed of the conveyor at various stages can be controlled to reduce the overall throughput time of the articles through the machine and ensure that the articles are properly washed. <IMAGE>

Description

WASHING MACHINE This invention relates to a washing machine, and particularly, but not exclusively, to a washing machine of an industrial type.

Industrial washing machines are used to wash a wide range of articles in an industrial environment. In particular it is often necessary to be able to wash and degrease metallic articles such as components for machines. It may also be necessary to wash other types of articles, for example, plastic mouldings, extrusions and suchlike.

A known type of industrial washing machine is a so called batch type machine, in which articles to be washed are placed in a housing which comprises the main body of the machine.

Once the articles have been placed in the machine the washing and drying cycle commence. At the end of the cycle, the articles which have been washed and dried are removed, and further batches can be placed in the machine for washing.

A disadvantage of this known machine is that the number of articles which can be washed per unit time is relatively low.

In addition, it is not economical to run the machine until a sufficient number of articles to be washed has been assembled. This means that it may not be possible to wash a particular article immediately as it may be necessary to assemble a sufficient number of other articles to make up a batch.

A second known type of industrial washing machine is a so called In line machine. Such a machine comprises a washing station and drying station, and a conveyor belt which runs through the washing station and drying station. Objects to be washed are placed on the conveyor belt which conveyor belt transports the articles through the washing station, followed by the drying station and finally out of the machine. The washing station comprises a housing containing a plurality of ducts which each extend transversely around the conveyor to forum a series of ribs. The ducts contain nozzles through which washing fluid is sprayed onto the articles passing through the washing station.

A problem with this known in line washing machine is that the dimensions of the machine have to be large due to the presence of the ribbed duct formation. This is because in order to achieve a spray pattern which produces an even distribution of spray of sufficient force over the articles to be washed, the ribbed ducts must be placed a certain distance away from the conveyor. This results in a machine which is very large and expensive.

According to a first aspect of an invention there is provided apparatus for washing articles, said apparatus comprising: a washing station comprising a housing; and at least one duct including a plurality of nozzles; conveying means for transporting the articles through the washing machine in a line of travel, characterised in that at least a portion of the at least one duct extends substantially parallel with the line of travel of the articles.

Preferably the apparatus further includes a drying station adjacent the washing station.

Preferably the apparatus includes a plurality of ducts, at least a portion of each of said ducts extending substantially parallel with the line of travel of the articles.

Preferably the position of the ducts and/or nozzles relative to the line of travel of the articles is adjustable.

There has hitherto existed a prejudice in the field of industrial washing machines which has led skilled workers in the field to believe that the ducts in the washing station must run in a ribbed formation transversely to the direction of travel of the articles and around the conveyor belt. This leads to in line machines which are very large in order to incorporate the transversely oriented ribbed ducts. The large dimensions result from the fact that the ribbed ducts must be positioned a certain distance away from the conveyor in order to ensure that the spray pattern produces a continuous spray on the articles to be washed. This leads to a machine which is very wide.

At least one duct of the present invention extends substantially in the direction of travel of the articles .This allows the width of the machine to be significantly reduced due to the fact that the ducts do not run around the conveyor in a ribbed type pattern. In addition it has been found that by having ducts running substantially in the direction of travel of the articles , a suitable spray pattern can be achieved without having to position the ducts a long distance away from the conveyor belt.

The washing machine according to the present invention therefore is smaller and less expensive than existing in line machines.

According to a second aspect of the invention there is provided apparatus for washing articles, said apparatus comprising a washing station comprising a housing; and at least one duct including a plurality of nozzles for directing fluid towards articles;and conveying means for transporting the articles through the machine in a line of travel, characterised in that the machine further comprises control means for selectively controlling the speed of the conveying means.

Preferably the apparatus includes a drying station adjacent to the washing station and typically the control means allows selective control of the conveying means as it passes through the drying station.

The presence of the control means improves the washing efficiency of the machine according to the present invention. For example, articles requiring a thorough wash are allowed to dwell within the washing station for a longer length of time in order to allow the contaminants to be removed from the articles.

Preferably the at least one duct is rotatably adjustable in order to alter the angle of the nozzles formed in the duct.

Preferably the machine comprises a plurality of ducts each of which extends substantially in the same direction as the line of travel of the articles. In one embodiment the ducts are connected by connecting ducts.

Preferably the conveying means is a conveyor belt and the line of travel of the articles is defined by the longitudinal axis of the belt.

Preferably the control means comprises a switch for switching between a continuous mode and an indexing mode.

The continuous mode allows the conveying means to travel at a constant speed resulting in articles on the conveying means passing through the machine at continuous speed. Typically this is suitable for lightly soiled articles.

The indexing mode is suitable for use with articles which are more heavily soiled. The indexing mode allows the conveying to stop or slow down in order that the articles spend a longer time within the washing station. The speed of the conveying means can also be caused to increase up between indices in order to minimise the total through time of the wash cycle.

Preferably, the selector switch comprises an electric circuit comprising two potentiometers. Each potentiometer can be set to the desired conveyor speed for both modes.

Advantageously the drying station contains a plenum chamber.

Preferably the plenum chamber comprises a plurality of delivery nozzles positioned on a surface above the conveying means, and heating means positioned below the conveying means.

The delivery nozzles are used to deliver air onto the articles passing through the drying station. The air is directed down the to the heating means positioned below the conveying means where it is heated up. Once the air has been heated, it will rise up through the conveying means and exits the plenum chamber via an output port positioned above the conveying means.

Preferably, the machine further comprises an input station and an output station. The input station can be used to place articles on the conveying means prior to the articles passing into the washing station.

The output station is positioned adjacent to the drying station and articles can be removed from the machine once they reach the output station.

Specific embodiments of the invention are now described with reference to the accompanying drawings wherein; Figure 1 is a perspective view of a washing machine according to the present invention; Figure 2 is a perspective view of the machine of Figure 1, in which the lid of the washing station has been removed; Figure 3 is a schematic representation of a detail of the machine of Figure 1 showing a first embodiment of the configuration of ducts in the washing station; Figure 4 is an elevation of a washing machine according to the invention in a second embodiment; Figure 5 is a schematic representation of the plenum chamber of the machine of Figure 1; and Figure 6 is a circuit diagram forming part of the control means of the machine of Figure 1.

Referring to Figures 1 and 2 a washing machine according to the present invention is designated generally by the reference number 10. The machine comprises a washing station 11, a drying station 12, and a conveying means 13. The machine further comprises an input station 14 and an output station 15. The conveying means comprises a conveyor belt which is used to transport articles to be washed through the machine 10. Objects to be washed are placed on the conveyor belt 13 at the input station 14. The articles then enter the washing station 11 where they are washed before being transported out of the washing station into the drying station 12 to be dried. The articles then exit the machine at output station 15.

The washing station comprises a housing 16 and a plurality of ducts 17. Each duct comprises a plurality of nozzles 18, and the configuration of the ducts is shown in more detail in Figure 3. Each duct is orientated substantially in the direction of conveyor travel. Surprisingly it has been found that this configuration can be used to produce a consistent spray pattern allowing the articles to be washed to be uniformly sprayed by a cleaning fluid. In addition, it has been found that the configuration results in the dimensions of the machine being significantly reduced when compared to other in line type washing machines.

When the articles to be washed are in the housing station 11, cleansing fluid such as water and detergent is supplied to the ducts 17 by means of a pump(not shown).

A further advantage of the configuration of ducts as shown in Figure 3 is that the orientation of the nozzles can be altered by rotating the ducts appropriately. This means that the setting of the ducts can be adjusted to suit the particular size and/or shape of an article to be washed in the machine 10.

Figure 4 illustrates a further embodiment of a washing machine according to the invention and the same features as Figures 1-3 are represented by the same numerals. However an alternative configuration of ducts 17 is shown wherein the major portion of the ducts extends in the direction of the travel of the articles. However in this instance portions 17' connect other ducts (not shown) running parallel therewith but displaced in a horizontal plane to allow washing fluid flow between ducts while still maintaining the advantages of the invention as claimed.

The washing station 11 further comprises a filter 19 which filters waste prior to disposal.

Referring to Figure 5, the drying station 12 is shown in more detail. The drying station 12 comprises a plenum chamber having a plurality of delivery nozzles 40 extending from an upper surface 41 of the chamber 12. The delivery nozzles 40 are positioned above the conveyor belt 13 and are used to direct air or other fluid onto articles to be dried. The chamber 12 further comprises heating means 42 in the form of a heating coil. In use, air is directed onto articles to be dried from the delivery nozzles 40. The air is then directed onto the heating element 42 where it is heated up. When the temperature of the air has been sufficiently raised, the air will rise due to its higher temperature. The hot air will then pass through outlets 53, through the conveyor belt 13 and thus will further dry the articles positioned on the conveyor belt 13. The air then exits via an exit duct (not shown).

The machine 10 further comprises control means 50 used to control the speed of travel of the conveyor belt. The conveyor belt is driven by a motor 51.

In one mode of operation, the speed of travel of the conveyor belt is set at a constant level. Objects to be washed by the machine 10 are placed on the conveyor belt at the input station 14, and travel through the machine via the washing station 11 and then the drying station 12 at a constant speed before exiting the machine at the outlet station 16.

An alternative mode of operation is known as the indexing mode. Such a mode is useful when it is required to more thoroughly wash articles which are heavily soiled. In such a situation it is desirable for the articles to remain in the washing housing for a longer period of time. The control means can be used to adjust the speed accordingly. In addition, in order to reduce the overall through time of articles in the machine 10, the control means is used to speed up the conveyor belt between indices. In other words, an article to be washed can be placed on the conveyor belt at input station 15. The article will then travel on the conveyor belt a relatively high speed until it reaches a predetermined point within the washing station 11. At this point the conveyor stops until a preset time elapses. At this point the conveyor speed again increases when taking the article into the drying chamber.

To index a conveyor is to cause it to move a predetermined distance and to then stop for a predetermined time. This process is repeated.

The "length of index" is the distance a given point on the conveyor will move in a given time. In other words, if a conveyor moves at a speed of one metre in one minute and the machine is set to allow the conveyor to move for a period of 30 seconds then the length of index will be half a metre.

Similarly if the time is set for one minute, the length of index is one metre.

In order to effect the indexing mode, the circuitry used to control the machine comprises two potentiometers and the circuitry is represented in Figure 6 and the conveyor drive control circuitry including a time switch 55 is represented by the numeral 54, the control circuitry for the heating means 56 and the control circuitry for the washing fluid pump at 58. Thus the circuitry provides a selector switch and a timer for the control of the conveying means and means for controlling the flow and collection of the washing fluid into the machine and the heating and induction of the drying air.

The potentiometers can each individually be set to produce a particular desired conveyor speed.

The motor used to run the conveyor is preferably a DC motor and is run in conjunction with a variable speed control.

The presence of two potentiometers ensures that the conveyor can run at different speeds depending on whether the machine is running in the continuous mode or in the index mode.

The conveyor belt should ideally run at a reasonably slow speed when in the continuous mode. A suitable speed is, for example, 300-600 mm per minute to enable the article to be washed to washed and dried efficiently.

If the machine is running in the index mode the conveyor should ideally be able to run at a faster speed, for example, 2000 mm per minute. This is because it is purely used to move the article from station to station. Once the article enters a particular station, the conveyor will stop or at least be slowed down for a predetermined length of time. It is therefore preferable that the time spent between stations is reduced as far as possible.

The potentiometers are individually adjustable throughout the full range of the conveyor speed. Once set, the speeds can be achieved by the selector switch on the control panel.

The present invention provides a washing machine apparatus which allows articles to be washed effectively and completely while at the same time providing ducts in a configuration such that the size of the apparatus can be kept to a minimum.

Furthermore the provision of control apparatus whereby the movement of the articles through the washing machine can be controlled allows improved washing efficiency, the washing cycle to be tailored to specific washing needs for specific articles and the throughput time of said articles to be reduced.

Claims (20)

1. Apparatus for washing articles, said apparatus comprising; a washing station comprising a housing; and at least one duct including a plurality of nozzles; conveying means for transporting the articles through the washing station in a line of travel, characterised in that at least a portion of the at least one duct extends substantially parallel with the line of travel of the articles.

2. Apparatus according to claim 1 wherein the apparatus includes a plurality of ducts, a portion of each of said ducts extending substantially parallel with the line of travel of the articles.

3. Apparatus according to claim 2 wherein each of the ducts are interconnected by connecting ducts.

4 . Apparatus according to any of the preceding claims wherein the length of the at least one of said ducts extends from one end of the washing station in the direction of travel of the articles.

5. Apparatus according to any of the preceding claims wherein the position of the ducts and/or nozzles relative to the line of travel of the articles is adjustable.

6. Apparatus according to claim 5 wherein the at least one duct is rotatable to alter the angle of the nozzles thereon.

7. Apparatus according to any of the preceding claims wherein the conveying means is a conveyor belt.

8. Apparatus according to claim 7 wherein the line of travel of the articles is defined by the longitudinal axis of the conveyor belt.

9. Apparatus according to any preceding claim wherein the apparatus further includes a drying station adjacent the washing station and through which the conveying means passes.

10. Apparatus according to claim 9 wherein the drying station comprises a plenum chamber.

11. Apparatus according to claim 10 wherein the plenum chamber comprises a plurality of delivery nozzles positioned above the conveying means, and heating means positioned below the conveying means.

12. Apparatus according to any preceding claim wherein there is provided an input station at the start of the conveying means and an output station at the end of the conveying means.

13. Apparatus for washing articles, said apparatus comprising; a washing station comprising a housing; and at least one duct including a plurality of nozzles for directing fluid towards said articles; and conveying means for transporting the objects through the machine in a line of travel, characterised in that the machine further comprises control means for selectively controlling the speed of the conveying means.

14. Apparatus according to claim 13 wherein the control means includes a selector switch for selecting the mode of movement of the conveying means between either of a continuous or in an indexed manner.

15. Apparatus according to claim 14 wherein the selector switch comprises an electric circuit including two potentiometers.

16. Apparatus according to claim 15 wherein each potentiometer can be set to provide the desired speed of the conveying means at any instant in any mode of movement.

17. Apparatus according to claim 14 wherein, when in indexed mode, the conveying means is caused to stop/ or slow down, when articles thereon pass through the washing station.

18. Apparatus according to any of the claims 13-17 wherein the apparatus includes a drying station adjacent the washing station and the control means allows selective control of the speed of the conveying means as the same passes through the drying station.

19. Apparatus according to claim 18 wherein further control means are provided for controlling any, or any combination of, heating means, washing and/or drying fluid supplies.

20. Apparatus as hereinbefore described with reference to the accompanying drawings.