TECHNICAL FIELD The invention relates to a method and apparatus for receiving computer- analysed/graded oblong objects, such as whitefish of any size, and delivering them automatically to predetermined compartments, containers or onto output conveyor belts for further processing according to the grading, and the apparatus comprises an input equipment, which consists of two endless conveyor belt chains, driven by a drum motor, and one or more oblong crossbars fastened between them, an opening/closing equipment and an output equipment, which is an end station in this process.

The computer-analysis/grading, which is not a part of this invention, can be by weight, length or computer image and the computer sends a signal for each graded object to the opening/closing mechanism as a command to open for access to a compartment for the grade in question at the exactly right time. The number of grades is as required.

BACKGROUND ART Various methods and equipment have been used in the past for the purpose described, i. e. delivering oblong objects, such as whitefish, from the place of grading to the correct operating stations on a processing line according to the grading. These methods include everything from e. g. a manual method of grading and picking the fish up into wheelbarrows, a container or onto a conveyor belt-to having various types of grading machines, such as shakers with holes or slits, horizontal or tilted grating in any number of variations; roller-graders, with either stripped or snail-formed rollers grading by thickness; or belt graders with belts or cords that both grade and deliver the whitefish into predetermined compartments, containers or onto output conveyor belts.

The method and apparatus that has mostly been used in recent years in fish processing lines, following the computerisation of analysis and grading as described above, which is considered traditional today, for receiving raw material from such grading equipment and moving it to points of destination, is a conveyor belt with flaps. The flaps are generally powered by pneumatic jacks kicking the object or raw material in question from the conveyor belt at the correct processing station or into a container, according to a signal from the grading equipment. There can be many flaps, depending on the number of grades and/or the number of processing stations or containers.

The major disadvantage of the said traditional method and equipment is that the raw material is subjected to an unnecessarily harsh treatment and even damage when kicked from the conveyor belt ; flaps need to return to their initial position to be ready for the next object, which delays the process; and the equipment takes up a considerable amount of space; and there are many points of wear.

Another kind of a receiving/delivering conveyor belt system referred to above is a unit disclosed in EP-Patent n° 0351778 A2, which consists of one or more revolvingly ocillating conveyor belt around an ocillation axis extending in parallel and close to one of the belt's longitudinal edges, where the whole conveyor belt can, upon action of control means, lower laterally for the discharge of the carried object after command from a sorting unit of different kinds. For not to deliver the object to harshly onto different secondary conveyor lines or into containers arranged at the unit itself or even make the object leap over the underlying receivers the conveyor belts are stopped at the beginning of the lowering. This means that the conveyor belts have to return to their initial positions and start running again on transport speed to be ready for the next object.

This again means a delay in the process; the unit takes up a considerable amount of space when objects are to be sorted/discharged to multiply of grades; and there are several points of wear.

DISCLOSURE OF INVENTION The object of the present invention is to provide a method that will work towards a much better treatment of graded and transported raw material and is fast aswell-also an apparatus that takes up less space, has fewer points of wear and does not require time and energy for stopping before returning to an initial position like the traditional equipment mentioned above.

This object is achieved by the method set forth in the characterising portion of patent claim No 1, which is new and special in that the objects are moved to and across one or more turnable, oblong and substantially trilateral opening-closing rollers and this equipment delivers each analysed object to an output equipment, by turning one given roller approximately 1/3 of a circle.

The object is also reached with apparatus according to patent claim No 5, which is characterised in that the crossbars of the endless, but bottomless, conveyor belt stand on edge when they move across an almost horizontal and even surface, formed of a guiding board and the sides of one or more turnable, oblong and substantially trilateral opening- closing rollers, which are placed in a straight line one after the other and the turning of the rollers is made possible by clutches and a chain which is also driven by a drum motor through a drive mechanism. Below the rollers are endless output conveyor belts arranged transversely, one or more, preferably of the same number as the rollers.

The method and the apparatus is also special, according to the subclaims 2 and 3, in that each of the turnable, oblong and substantially trilateral opening-closing rollers stands for one determined grade of size or weight and due to the trilateral shape of the rollers they only have to turn 1/3 of a circle from the initial position with one of their three sides facing up in a horizontal position in order to deliver a finally graded object and are at the same time ready with an adjacent side in initial position in order to receive the next object and deliver it to output equipment or pass it over to the next roller.

Further advantageous embodiments and achievements of the present invention are disclosed in the rest of the subclaims.

This way gives three advantages: the objects/raw material does not receive the same harsh treatment as with the kicks of flaps/jacks-they glide softly from the opening- closing rollers down to the output belts; time is saved because the opening-closing rollers do not need to stopp before return to their original position and thirdly space is saved, as the new and special equipment takes up considerably less room than a traditional conveyor belt with flaps and jacks.

BRIEF DESCRIPTION OF DRAWINGS The invention is described in more details in the following chapter with references to explanatory figures, where: -Figure 1 shows the basic arrangement of the apparatus, side view -Figure 2 shows the basic arrangement of the apparatus, end view -Figure 3 shows the basic arrangement of the apparatus from above -Figure 4 shows a cross section of a opening-closing roller -Figure 5 shows a front view of a opening-closing roller -Figure 6 shows the turning process of a opening-closing roller, how it delivers an object.

BEST MODE FOR CARRYING OUT THE INVENTION Figures 1 to 3 show, in addition to the basic description of the machinery, a computer controlled analysing equipment (11), which can be e. g. a weighing belt, but is not a part of this invention except that it delivers analysed and graded objects, especially whitefish, to the input equipment, which is a kind of bottomless conveyor belt. The method consist therefore in receiving the analysed whitefish with the bottomless conveyor belt, moving it to the opening/closing equipment, which is made up of one or more opening-closing rollers (4) and drive mechanism (5), (6) and (3), and directing it to the correct point of execution in the process by turning one of the opening-closing

rollers (4) according to the analysing equipment (11) and delivering it down to the output equipment (7).

The bottomless conveyor belt (which may be likened to a rope ladder with the ends spliced together forming an endless ladder) is made up of two strong, endless chains (1) one at each side of the equipment and a few flat, oblong crossbars (2), that are fastened perpendicularly to the chains so that they are vertical on their edge, when the conveyor belt moves across an approximately horizontal and level surface, formed by a kind of guide (9) along with the sides (10) of the opening-closing rollers (4) in the rollers' initial position. The space between the chains (1) is at least equal to or larger than the length of the rollers (4). The chains and the crossbars, which are driven by a drum- motor (3), with a chain wheel at both ends, form many bottomless frames, which along with the previously mentioned space between the chains are preconditions for the turnable opening-closing rollers (4) being able to turn without hitting the input belt.

Opening-closing rollers (4) are turnable, oblong and largely trilateral. The sides of their cross section are of equal lengths and it is therefore like an equilateral triangle, i. e. the radii dividing the angles form three 120° angles, as shown in figures 4 and 5. Each roller stands for one grade of size or weight, to be delivered after, and it is possible to have as many rollers as necessary, depending on the number of grades required. The rollers are placed one after the other in a straight line, so that they can turn without hitting each other and the turning of the rollers is made possible by a chain (5), which is also driven by a drum-motor (3) through a drive mechanism (6), and clutches (8). Chain (5) runs continuously like chains (1) while the grading/delivering system is operating, but the opening-closing rollers are kept stationary by clutches (8), until a signal arrives from the analysing equipment (11) indicating a graded object. Then one of the clutches (8) connects the appropriate roller (4) to the chain-equipment (5) and then the roller turns independently of the other rollers and the object in question (12) in figure 6 is turned down to the appropriate conveyor belt or container of the output equipment (7) which is placed below the opening-closing rollers.

Clutches (8) can be of various types, such as magnetic-or freewheeling-clutches, but instead of these and the chain-equipment (5) and (6) it would e. g. be possible to use a stepmotor for each roller, which would be simpler-but possibly more expensive.

The output equipment (7), seen on figures 1 and 2, can be endless conveyor belts, the same number as the opening-closing rollers (4), or the same number of containers. The purpose of this equipment is to move completely graded objects to the required points of execution in the process line-but is in no other way a part of this invention.

Figure 6 shows in five steps (I to V) how one opening-closing roller (4) turns approximately 1/3 of a circle (i. e. 120°) and turns off one graded object (12), which falls then through an opening that opens between it and the next roller in the line (No 13) and is shown greyed in the figure-but is stationary), down to the appropriate output belt.

The opening will be large enough for the objects to be delivered, if the length of each side of the roller's cross section is at least twice the diameter or the width of the largest object to be delivered. Step V on the figure shows that the final position of roller (4) is when its edge (14), marked with 0, has moved the said 120° and now points down. The roller's (4) next side after side 10 is now in an approximately horizontal position whereby the roller has come to a new initial position and is prepared to receive the next object, if needed. Roller (13) is stationary as before.

Figure 6 also shows that one of the main prerequisites for this opening and closing mechanism being able to perform the method of this invention, is the trilateral form of the rollers (4) and that the trilateral form is also an equilateral triangle.

Another prerequisite is that the length of the opening-closing rollers (4)-and hence the space between chains (1) and the length of crossbars (2)-be at least equal to the longest oblong object to be graded, as the objects must enter the rollers crosswise in order to pass down through the opening in question, which is formed between the rollers when they turn. The objects, which are to be delivered, land crosswise automatically due to effects from the underlying track, when the crossbars (2) push them across guiding boards (9) and surfaces (10).

The space between crossbars (2), their speed and the rotating speed of the opening- closing rollers (4) along with timing of the turning of the rollers must be synchronised very precisely so that the rollers'rotating speed equals the crossbar speed and the space between them is then also considered. A roller must never start to turn before the respective crossbar has passed the vertical line from the drive-axle of that roller across which the bar is passing-or else there will be a collision. At that point the roller's rotation can start and the roller turns then 1/3 of a circle in the same period of time that it takes the crossbar to move the length: from the said vertical line of the drive-axle, until it has travelled its thickness across the rim of the next roller. This means that the frame, which has until this point had a bottom of surface (10) on one roller after the other, becomes bottomless for a split second and the object/raw material, which is in that point in front of the crossbar in question and the grading computer has attributed exactly to this compartment, container or output conveyor belt, falls down in the correct place, see figure 6.