GB2156326A

GB2156326A - Feeding articles, e.g. trays, to washing machine

Info

Publication number: GB2156326A
Application number: GB08506693A
Authority: GB
Inventors: Thomas Eidevag; Gote Eriksson
Original assignee: Wexiodisk AB
Current assignee: Wexiodisk AB
Priority date: 1984-03-24
Filing date: 1985-03-14
Publication date: 1985-10-09
Also published as: GB2156326B; SE454234B; FI850769A0; SE8401648D0; FI850769L; SE8401648L; GB8506693D0

Abstract

Trays (4) are introduced into a washing machine in a horizontal position on supports (9,10) at opposite edges of the trays, so as to form a stack. One edge portion of the lowermost tray is released, such that the tray is swung about the opposite edge (arrow A) while the superjacent trays are maintained at both edges. After such a pivotal movement, said tray is caused to descend onto a conveyor running through the machine and to rest on the conveyor in an upright position. Two horizontal supports hold the trays (4) in a stack, one support (9) being fixed and the other consisting of a rotary feed means (10). The feed means has a lower semi-circular supporting surface (11) and a superjacent semi-circular cam surface. Upon rotation, the supporting surface releases the lowermost or bottom tray while the cam surface has just before been swung into the stack and is supporting the rest of the trays. There may be a control device 22 arranged to inhibit tray release unless a certain number are present. The washing machine has spray wash, spray rinse, and drying sections. <IMAGE>

Description

SPECIFICATION A method and a device for feeding a machine for washing uniform articles The present invention relates to a method and a device for feeding a machine intended for washing uniform articles, such as trays or the like.

When washing up different kinds of utensils in larger kitchens, restaurants and the like, use is often made of belt-type dishwashing machines which comprise a belt conveyor feeding the articles to be washed either directly on it or in baskets through the dishwashing machine. If possible, the person who delivers the articles to be washed himself places them in the baskets of the dishwashing machine, so that the kitchen staff need only move the baskets from the point of delivery to the feed table of the dishwashing machine. The trays must then be taken care of separately.

When the trays normally used for the articles to be washed up have been emptied, they must be taken care of and cleaned. In many cases, this is done completely by hand, since trays of certain kinds of materials will be damaged if run through a conventional belt-type dishwashing machine because of the relatively long time of residence in the machine and because of the high temperatures prevailing therein.

In the attempts at also mechanizing the handling and cleaning of the trays so as to relieve the kitchen staff, use is made of newtypes of dishwashing machines in which the trays are run one by one through the machine at a very high speed, such that the time of residence in the machine is only in the order of 1 - 4 seconds. By such a short residence time the material of the trays will not become heated to such an extent that the trays risk being damaged.

Since the trays when used are often delivered most irregularly, ie are not delivered at regular time intervals, a substantial overcapacity must be maintained for taking care of the delivered trays and supplying them to the dishwashing machine.

The object of the present invention therefore is to solve the above-mentioned problems by providing a method which allows the eating guest delivering the tray to be the last person to touch the tray before it is washed up and ready to be used again. Hence, the invention has for its object to provide a method which, independently of the rate of delivery of the trays, allows mechanical feed thereof to a dishwashing machine.

According to the invention, this object is achieved by a method comprising the steps of introducing the articles, such as trays, on top of each other on a horizontal support and stacking them thereon, supporting a first edge portion of the lowermost or bottom article while releasing a second spaced-apart edge portion and supporting a superjacent second edge portion of the second article from the bottom, whereby the lowermost article is swung about said first edge portion to a substantially vertical position on a conveyor running through the machine.

In order to avoid that any left-overs and the like remainig on the articles, preferably trays, may cause the trays to adhere to each other, it is suggested according to the invention that the second edge portion of the second article from the bottom is suitably raised as the second edge portion of the lowermost article is being released.

Further, the invention is suitably characterized in that the release of the lowermost of the stacked articles is carried out at substantially regular intervals, whereby the stack will serve as a buffer with respect to articles supplied at irregular intervals.

In order that the eating guest should always have a space where he can readily place or deliver his tray, it is suitably contemplated according to this invention that the release of the lowermost of the stacked articles is interrupted when the stack contains only a predetermined minimum number of articles.

A further object of the invention is to provide a device for carrying out the method.

According to the invention, this object is achieved by means of a support for a stack of articles, preferably trays, said support comprising a supporting member for a first edge portion of the lowermost or bottom article of the stack and a feed means for cooperating with a second spaced-apart edge portion of the articles, said feed means being adapted when actuated to release the second edge portion of the lowermost article and to retain the second edge portion of the second article from the bottom, and a conveyor which is disposed below said supporting member for receiving an article which upon release by said feed means has been swung about the supporing member to a substantially vertical position.

According to the invention, the device is suitably also characterized in that the feed means is rotatable, that it has a lower supporting surface which is adapted, in a first position of rotation of the feed means, to support the second edge portion of the lowermost or bottom article and, in a second position of rotation of the feed means, to release said edge portion, and a superjacent lifting surface which is adapted to engage and lift the second edge portion of the second article from the bottom when the feed means is rotated from said first to said second position of rotation, and to allow the second edge portion of said article to drop onto said supporting surface when the feed means is rotated back to said first position of rotation.

Further, the invention is suitably also characterized in that a sensor is arranged for recording the number of articles on the support and for stopping the feed means when only a predetermined minimum number of articles remain thereon.

The invention will now be described in greater detail, with reference to the accompanying drawings, in which Figure 1 is a schematic side view of a dishwashing machine for washing articles one by one; Figure 2 shows the dishwashing machine in Fig.

1 as viewed from the left-hand end in Fig. 1; Figure 3 illustrates schematically and with certain parts broken away, the feed unit proper of the dishwashing machine of Figs. 1 and 2, as viewed from the right in Fig. 2; Figure 4 illustrates the feed unit of Fig. 3 as viewed in the direction of feed, ie from the left in Fig. 1; Figure 5 on a larger scale, schematically illustrates the upper part of the feed unit as viewed in a direction opposite to that of Fig. 3; Figure 6 illustrates the upper part of the feed unit as viewed in a direction opposite to that of Fig. 4; Figure 7 illustrates one of the feed means, best visible in Figs. 5 and 6, as viewed straight from the side;; Figure 8 illustrates the same feed means as viewed straight from above in the same position of rotation as in Fig 7, and Figure 9 illustrates the feed means turned 90 in relation to Fig. 7.

The invention will be described hereinbelow with reference to a machine which is designed especially for washing trays, but it is self-evident that the same principle of operation with very small modifications is also usable for washing plates or the like which are fed one by one through the dishwashing machine.

The dishwashing machine illustrated in Figs. 1 and 2 has an inlet section 1 with a feed opening 2 for introducing the trays to be washed. The dishwashing machine further comprises a conveyor intimated by reference numeral 3, on which the trays designated 4 are fed one by one in an upright, substantially vertical or slightly inclined position through the dishwashing machine from the left to the right in the drawing.

For washing the trays, the dishwashing machine comprises a pump 5 which supplies heated washing liquid admixed with detergent through a number of spraying lines 6, such that washing liquid is directed against the passing trays. Further, the dishwashing machine comprises a corresponding spraying line 7 for rinsing and a device for blowing the washed and rinsed trays dry.

From the dishwashing machine, the trays are discharged onto a so called dispenser 8 which is designed in such a way that the trays will descend gradually as new trays are being supplied from above. Suitably, the dispenser 8 may be provided with wheels and be designed in such a way that it is suited for transporting the washed and dried trays directly back to the restaurant premises or the dining-hall.

Since trays, eg in a military dining-hall, can be delivered in very large numbers during short periods of time, rational handling of the trays is required for storing them in the inlet section of the dishwashing machine before they are introduced in the machine and cleaned. Further, if the trays are delivered directly by the user, it is necessary that the trays can be placed on an easily accessible surface on a convenient level. The invention meets these two requirements extremely well.

As appears from Figs. 3 and 4, the inlet section 1 has, at the lower edge of the feed opening 2, supporting means which are arranged along opposite edges of the trays and one of which is a longitudinal supporting member or supporting rail 9 which extends along a first edge portion of a tray. Along the opposite edge portion of the tray, there are provided at least twos feed means 10 which have lower supporting surfaces 11 on the same level as the supporting rail 9. Thus, supporting means will be provided along two opposite edges of the trays which can be placed horizontally thereon.

The feed means 10 are designed in such a manner that they can support, together with the supporting rail 9, a large number of trays 4 forming a buffer when the delivery of the trays takes place at a higher rate than the dishwashing machine is capable of handling. Further, the feed means 10 are designed in such a manner that, while supporting the entire stack of trays received in the inlet section 1, they separate the lowermost tray at regular intervals such that it is released at its right- hand edge in Figs. 2 and 4. In this manner, the lowermost or bottom tray will be swung clockwise, as intimated by the arrow A, while the left edge of the tray is still resting on the supporting rail 9.The right edge of the tray can then be guided along guide rails 12 which are curved along a circular arc and extend from the area immediately underneath the feed means 10 to the area immediately adjacent an opening 13 which is disposed straight above the conveyor 3 which, during the washing operation, transports the trays 4 through the dishwashing machine.

The invention also comprises a suitable guide system for guiding the movements of the feed means 10 so as to ensure that a tray 4 swung down onto the conveyor 3 has actually been removed by the conveyor before the next tray is fed down by the feed means 10.

In Figs. 5 and 6, it is shown more clearly how the feed means 10 are arranged and how they cooperate with each other. Thus, it appears from these two figures, and to some extent also from Figs 3 and 4, that the feed means 10 are arranged on substantially vertical shafts 14 which are mounted in bearings 15. At the upper ends, the shafts 14 have sprockets 16 which are located above the upper boundary edge of the inlet or feed opening 2.

The sprockets 16 are interconnected by means of a chain 17 intimated by dash-dot lines, such that the shafts 14 and, hence, also the feed means 10 can be rotated in synchronism under the action of a drive motor 18.

The feed means 10 are arranged so as to rotate one revolution at each feed cycle. For establishing suitable stop positions, use is made of a cam disc 19 which by a cam follower pulley 20 and a microswitch 21 controls the operation of the drive motor 18. For controlling the drive motor 18, use is also made of a sensor 22 which is disposed in such a manner that it is actuated by a stack of trays resting on the supporting rail 9 and the supporting surfaces 11, whereby operation of the feed means 10 is possible only when the stack contains a certain number of trays.Thus, if the number of trays on the feed means and the supporing rail falls below a certain permissible minimum level, the sensor 22 will respond thereto by being swung out to the position shown in Fig. 6 (Counterclockwise), whereby the operation of the feed means 10 is discontinued until the sensor 22 is again swung in the opposite direction as a result of being pressed away by the trays located on a higher level.

The control system further comprises another sensor which may be designed as a photocell device and which is placed in the area of the two guide rails 12. This sensor serves to sense and control the passage of a tray along the guide rails and down to the opening 13. This sensor is designed in such a way that it does not allow a new feed cycle of the feed means 10 until the tray previously fed has actually passed down onto the conveyor 3 and been removed thereby. This makes it possible to ensure that a new tray is fed down onto the conveyor as soon as the preceding tray has been removed, whereby the capacity of the dishwashing machine can be used maximally, which would otherwise be difficult, since the feed rate of the conveyor 3 preferably is continuously adjustable.

As intimated above, the feed means 10 are designed in such a manner that they will separate the lowermost or bottom tray in the stack and release it while the entire overlying stack is retained. According to the invention, this is achieved in that the feed means 10 consists of two substantially semi-circular discs 23 and 24 of which the lower disc 24 is provided with the above-mentioned supporting surface 11 on its upper side. The upper semi-circular disc 23 has a cam surface 25 which is facing upwards and serves to bring about the above-indicated lifting of the stack of trays as, at the same time, the tray located at the bottom of the stack is separated and released by the supporting surface 11.To this end, the two semi-circular discs are rotated approximately 180 with respect to each other, which means that while the lowermost or bottom tray is resting on the supporting surface 11, the front edge 26 of the cam surface will engage between the bottom tray and the superjacent tray when the feed means is rotated in the direction of the arrow B in Figs. 7 - 9.

In order that the feed means 10 for its use should not be restricted to a single type of tray, it is composed of four different discs of which the lowermost disc 27 and the uppermost disc but one 28 are inserts which can readily be exchanged and replaced by other discs of different thicknesses.

Thus, the vertical distance between the front edge 26 of the cam surface 25 and the supporting surface 11 may easily be adjusted to the thickness or the difference in vertical position of the different trays.

The invention can be modified within the spirit and scope of the accompanying claims. Thus, it goes without saying that both the dish-washing machine and its inlet section, as well as its mode of operation, can easily be modified to suit round articles, such as plates or the like. The same principle of operation can then be applied, and modifications need be made only in respect of the size and location of the supporting rail 9, the feed means 10 and the guide rails 12. Suitably, the supporting rail 9 may then be curved so as to follow part of the circumference of the round article, and the supporting rail may optionally also be divided into two shorter pieces, such that a three-point support is obtained against the edge portion of the round article.

Further, the inlet section 1 may of course have more than one inlet or feed opening 2, such that the articles to be washed may in principle be fed from all sides except the one where the feed means 10 are located.

Claims

1. A method of feeding a machine for washing uniform articles, preferably trays, characterized in that the articles are introduced on top of each other on a substantially horizontal support and are stacked thereon, that a first edge portion of the lowermost or bottom article is supported while a second spaced-apart edge portion is released and a superjacent second edge portion of the second article from the bottom is supported, whereby the lowermost article is swung substantially about said first edge portion to a substantially vertical position on a conveyor running through the machine.

2. Method as claimed in claim 1, characterized in that the second edge portion of the second article from the bottom is raised as the second edge portion of the lowermost article is being released.

3. Method as claimed in claim 1 or 2, characterized in that the release of the lowermost of the stacked articles is carried out at substantially regular intervals, whereby the stack will serve as a buffer for articles supplied at irregular points of time.

4. Method as claimed in any one of the preceding claims, characterized in that the release of the lowermost of the stacked articles is discontinued when the stack contains only a predetermined minimum number of articles.

5. Method as claimed in any one of the preceding claims, characterized in that said swinging of the articles is performed under gravity.

6. A device for feeding a machine intended for washing uniform articles (4), preferably trays, characterized by a support for a stack of articles (4), said support comprising a supporting member (9) for a first edge portion of the lowermost or bottom article (4) of the stack and a feed means (10) for cooperating with a second spaced-apart edge portion of the articles, said feed means being adapted upon actuation to release the second edge portion of the lowermost article and to retain the second edge portion of the second article from the bottom, and a conveyor (3) which is disposed below said supporting member (9) for receiving an article which upon release by said feed means has been swung about the supporting member to a substantially vertical position.

7. Device as claimed in claim 6, characterized in that said feed means (10) is rotatable, that it has a lower supporting surface (11) which is adapted, in a first position of rotation of the feed means (10), to support the second edge portion of the lowermost or bottom article (4) and, in a second position of rotation of the feed means, to release said edge portion, and a superjacent lifing surface (25) which is adapted to engage and lift the second edge portion of the second article from the bottom when the feed means is rotated from said first to said second position of rotation, and to allow the second edge portion of said article to drop onto said supporting surface (11) when the feed means is rotated back to said first position of rotation.

8. Device as claimed in claim 6 or 7, characterized in that a sensor (22) is arranged for recording the number or articles (4) on said support and for stopping the feed means (10) when only a predetermined minimum number of articles remain on said support.

9. A method of feeding a machine, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

10. A device for feeding a machine, substantially as hereinbefore described with reference to and as shown, in the accompanying drawings.