A DEVICE FOR EMPTYING TRAYS

Abstract: A device for emptying trays from waste, incorporating a sloping track (7) provided with pairs of cooperating carriers (9), adapted to retain a tray (2) at the edge region thereof, with the plane of the tray under an angle to the extension of the track, and wherein the carriers (9) are movable synchronously from a lower position in which the tray (2) is insertable into said carriers (9) to an upper position, in which the carriers (9) are arranged automatically to release the tray, which during the sloping transport, substantially due to the gravity, has been emptied from waste.

Description: A DEVICE FOR EMPTYING TRAYS The present invention refers to a device for emptying trays from different objects situated thereupon, but primarily food scraps, disposable articles, such as napkins, disposable cutlery and the like in waste handling of catering activities and the like, where helpings of food are served on trays, which after serving are taken care of for emptying and cleaning, and for removal of the refuse. In sites for such handling the removal of reusable items is commonly effected manually, and it also is common that napkins, empty disposable packages and the like are removed manually, which means an expensive manual work. The purpose of the present invention is to provide a device, by means of which emptying of trays can be effected automatically, without need of manual influence, and this has been achieved in that the device has been given the features defined in claim 1. Hereinafter the invention will be further described with reference to an embodiment schematically shown in the accompanying drawings. Fig. 1 shows schematically in side view a device according to the invention. Fig. 2 is a schematic view from above of the device according to the invention. Fig. 3 is a view in bigger scale and partly in cross section of a portion of the device according to the invention. Fig. 4 shows in a side view and with hidden parts shown in dash lines a detail forming part of the device according to the invention, and Fig. 5 shows the same detail as Fig. 4 from the opposite side thereof. Fig. 1 shows schematically and in side view a device according to the invention, which incorporates, or is connected to a conveyor 1, which in a mutually spaced apart manner transports trays 2 with (not further shown) waste towards one end 3 of the conveyor. At the end 3 of this conveyor 1 is provided a guide formed as two downwardly inclined guiding gutters 4, arranged with a mutual lateral spacing, substantially corresponding to the width of the conveyor, which at their side surfaces facing each other are provided with flanges 5 arranged substantially perpendicularly to the side surfaces. At the lower end of each of the guiding gutters 4 is arranged a movable plunger 6 projecting laterally thereinto, which plungers in neutral positions project into the associated guiding gutter 4 and thereby together preventing a tray 2 sliding on the guide, from falling out at the lower ends of the guiding gutters. A second conveyor 7 connects to the lower end of the guide formed by the guiding gutters 4, and which from the connecting position is inclined upwards, and incorporates parallel chain tracks 8, which, such as can be seen from above in the schematic Fig. 2, support a number of evenly spaced apart tray carriers 9, the design of which is further illustrated in Fig.s 3 and 4. As can be seen from Fig. 2, each chain track 8 comprises an endless chain 10, which is led over two spaced apart chain wheels 11, at least one of which is driven, and which have their axes arranged perpendicularly to the plane of inclination of each chain track. With this arrangement for the chain tracks the carriers 9 at the advance side will move obliquely upwards at a certain inclination, which substantially corresponds to the inclination of the guiding gutters 4. At the return side, the carriers 9' contrary thereto will move obliquely downwards with another inclination in relation to the base plane. For the sake of clarity Fig. 1 shows only one carrier 9 on the inner, advance side of the chain track, and one carrier 9' at the return side. Fig. 3 shows a cross section through a chain track 8, which in the case shown incorporates a beam 13 provided on a frame 12, in the embodiment shown a box beam, which at its side surfaces support ledgers 14, forming race tracks for the chain 10. Substantially C-shaped brackets 15 adapted to slide along said ledgers are attached to chain links of the chain 10 situated at evenly spaced apart positions. At the side facing away from the chain 10, each one of the brackets 15 support one of said carriers 9. Said carriers 9 incorporate, as can be seen in Fig.s 4 and 5, which show side views seen in directions away from and against the beam side, respectively, a substantially Y- shaped retainer slopingly attached to the C-shaped bracket 15, with a bottom wall 16 facing the bracket, and two mutually spaced apart side walls 16a, 16b arranged with decreasing mutual spacing in a direction from above and downwards, and which at the lower end between them form a slot 16c having a width well exceeding the height of a tray to be handled in the device. In the area of this slot 16c in the bottom wall 16 is provided an opening through which a movable, pretensioned arresting arm 17 is arranged to project into the slot, thus that the cross section thereof is divided into two narrower channels, which do not permit passage of a tray. In the embodiment shown the arresting arm 17 is provided with a shaft, which extends through a guiding 18 in connection to the bottom wall 16 and ends with a knob 19. The shaft is secured from moving out of the guiding by means of a stop 20, here in the form of a washer, and by means of a compression spring 21 it is imparted a pre-tensioning, urging the arresting arm to be pulled out of arresting position. Along the portion of the extension of each chain track 8, where the arresting arm 17 is intended to project into the slot 16c and thereby prevent passage of a tray, in the embodiment shown, at the frame is provided a longitudinal ruler 22, against which the knob 19 on the arresting arm 17 slides and thereby prevents the arresting arm 17 from moving out of the slot 16c under influence of the spring 21. In the discharge position, i.e. at the end of each chain track 8 facing away from the guiding gutters 4, this ruler 22 terminates and due to this the spring 21 can pull out the arresting arm 17 from the slot 16c, thereby allowing a tray to pass therethrough. In Fig.s 1 and 2 is also schematically shown an air ramp 23 provided in connection to the transition between the first conveyor 1 and the guiding gutters 4, which air ramp with a number of fixed and/or movable air nozzles 24 is adapted to direct a flow of air against the trays conveyed thus that at one hand waste is mechanically removed from the trays, and at the other hand thus that a paper or plastic cloth often used on such trays, and which may adhere thereto e.g. due to static electricity or liquid, is loosened from the tray. In Fig. 2 is also intimated how a sensor 25, e.g. a photocell, is provided to sense the position of a carrier 9, and via a cable 26 to transfer a signal to an actuation means 27 for the plunger 6, which projects into the track in the guiding gutters 4. One of the guiding gutters 4 and also one of the chain tracks 8 are preferably fixedly arranged in transversal direction, whereas the other preferably is movable laterally, such as illustrated schematically for one of the chain tracks at 28, in order to permit adjustment of the device for trays of different widths. The function of the device according to the invention is the following: When a tray 2, e.g. on the first conveyor 1 is getting closer to the parallel, downward sloping guiding gutters, the tray will tip over downwards and the edges of the tray will rest against the flanges 5 of the guiding gutter, thus that it under a substantial inclination slides down till engagement with the front portion of its edges against the plungers 6. When the sensor 25 detects a predetermined position for a carrier 9 on the two synchronously driven chain tracks 8, this will emit a signal, which causes the actuating means 27, e.g. by pneumatic actuation, to make the plungers 6 momentarily withdraw from the guiding gutters, and thereby permit the first tray to slide down and with its longitudinal edges slide into the hopper-shaped upper portion of the carriers 9, by which the tray thereupon in a strongly inclined position is conveyed upwards, during the time the arresting arms 7 block the slot 16c at the lower end of each carrier 9. At this upward transport any remaining waste on the strongly sloping tray will fall off and like the waste, which has fallen off the tray during the downward movement on the guiding gutters 4, fall down into or onto arrangements for disposal of the waste, such as a container, a conveyor belt for further transport, etcetera. When the pair of carriers 9 retaining the tray reaches the discharge position, the movement of the arresting arms 17 under influence of the springs 21 will not any longer be hampered by the ledger 22 cooperating with the knobs 19, and the arresting arms are pulled out off the slot 16c, whereby the tray due to the gravity will fall down onto a stack of trays, in tray compartments for a dish washing machine or the like. Due to the fact that the sloping guiding consisting of the guiding gutters is provided with plungers, which let a tray pass when a pair of carriers are situated in the correct position, the guiding gutters will operate as a hopper, in which several trays can wait for their turn for being transferred to the carriers. The invention is not limited to the embodiment illustrated in the drawings and described in connection thereto but modifications and variants are possible within the scope of the following claims.

Claims: CLAIMS 1. A device for emptying of trays, c h a r a c t e r i z e d t h e r e i n, that it incorporates an inclined track (7) provided with carriers (9) cooperating in pairs and arranged to retain a tray (2) at the edge region thereof, with the plane of the tray under an angle to the extension of the track, and wherein the carriers (9) are movable synchronously from a lower position in which the tray (2) is insertable into said carriers (9) to an upper position in which the carriers (9) are arranged automatically to release the tray, which during the sloping transport, substantially due to the gravity, has been emptied from waste. 2. A device as claimed in claim 1 , c h a r a c t e r i z e d t h e r e i n, that the carriers (9) are arranged on links of two parallel, inclined chain tracks (8), which are arranged at a mutual distance, thus that waste falling from a tray conveyed in the carriers, without problem may fall down to a collecting device for the waste positioned below the device. 3. A device as claimed in claim 1 or 2, c h a r a c t e r i z e d t h e r e i n, that the carriers (9) are each constituted by a bottom wall (16) having two side walls (16a, 16b) arranged substantially perpendicularly thereto, which have a mutual spacing decreasing in a direction from above and downwards, which at the lower end terminates in a slot (16c) having a width bigger than the height of a tray, whereby a movable arresting arm (17) is arranged to project into the slot (16c) during the movement of the carrier (9) to said upper position, wherein the arresting arm (17) is arranged to be moved out off the slot (16c) thereby releasing the tray. 4. A device as claimed in anyone of claims 1-3, c h a r a c t e r i z e d t h e r e i n, that a guide (4) is arranged to guide trays (2) in inclined position towards the lower part of said track (7), and which guide is provided with members (6) adapted to permit transfer of a tray directly into the hopper-formed carriers (9). 5. A device as claimed in claim 4, c h a r a c t e r i z e d t h e r e i n, that the guide is constituted by two parallel guiding gutters (4) having flanges (5) along which the trays may slide downwards, and that the members (6) for allowing transfer of a tray are plungers (6), adapted to block the lower part of the guiding gutters, and momentarily to be removed from their arresting position for feeding a tray therethrough. 6. A device as claimed in claim 4 or 5, c h a r a c t e r i z e d t h e r e i n, that said members (6) adapted to permit transfer of a tray are under influence of a sensor (25) adapted to detect the momentary position for a carrier (9), and in a predetermined position for this, to initiate momentary activation of said members (6). 7. A device as claimed in anyone of the preceding claims, c h a r a c t e r i z e d t h e r e i n, that means (28) are provided for varying the width of the inclined track/tracks (7, 4). 8. A device as claimed in anyone of the preceding claims, c h a r a c t e r i z e d t h e r e i , that an air ramp (23) is provided in connection to the inclined track/tracks (7,4), said air ramp having air nozzles (24) for causing a flow of air to act upon the trays.

Inventors: KIHLSTROEM CHRISTER, KIHLSTROEM, CHRISTER
Applicants: CENTRALSUG AB, KIHLSTROEM CHRISTER, AB CENTRALSUG, KIHLSTROEM, CHRISTER
Application year: 1996
Main classification: A47L15
IPC codes: A47L15, B65G47