BRIEF DESCRIPTION

The invention relates to rotary dividing disk shears for cut¬ ting narrow strips or bars of metal, plastics, etc., transversely, The cutting process is carried out between two circular, coopera¬ ting, cutting disks. The dividing shears can for instance be used as waste shears for chopping waste strip edges when trimming of ed¬ ges or si itt ing of coi Is.

BRCKGROUND TECHNICS

Dividing shears for materials moving forwards in a rela ively high speed often generate disturbing noise. Often they are not fea¬ sible to chop waste strips. Three different types of shears are common.

One has two straight cutting tools, the edges of whom move parallel against each other and just when cutting they overlap each other at a very narrow distance. The strip to be cut will be moved ahead in between the edges and when the shears move against each other then they cut the strip. If the material is fed ahead in a high speed to the cutting station and the cutting length is narrow the cutting tools must go to and fro in a very high speed, often generating high operating noise. Just when cutting off the strip in question it will be put to stop for a moment and that will also ge¬ nerate high noise. If for instance the shears are flying they move ahead together with the material when cutting off and then move back again to the starting-point between two cuts. The strip is able to be moved ahead without interruptions, but the shears will be more complicated to make and this pulsating movement will gene¬ rate much noise. It will also be some problem to chop the material to short lengths.

Rn other type of shears cut off the strip by rotating disks having edges round the disk's periphery. If the side plans of the disks are directed a little oblique-angled compared to the direc¬ tion of movement of the material for cutting and the rotating speed is very well adjusted it is possible avoiding to stop the material when mo ing ahead. On the other hand the part of the strip just be- fore the cutting station will be moved sideways during the cutting operation and then is going ahead on the other side of the shears. To get the strip back to the entrance side again it is for instance possible to let the disks be moved from each other a little bit, then let the strip go back to the entrance side of the shears and then let the disks be moved to again. This is a very complicated way and it is also difficult to execute all these different move¬ ments between two cuts when chopping.

Rgαin, another way is to let the whole shears twist just about a half turn round a vertical tap to change the entrance side. By next cut the material will be directed back to the previous entrance side. Due to that a big volume has to tuiist from one end to another and then back again the arrangement will be expensive and does not very well fit for chopping, most of all if the mate¬ rial must be directed ahead very rapidly.

By the third type of dividing shears there are two disks rotating in the same plan but a little bit separated. To the perip¬ hery of the disks there are fitted cutting tools having the direc¬ tion of the edges across the material direction of movement and across the plan of the disks. The cutting tools shall also be moun¬ ted in that way that their edges will be met two by two when rota- ting the disks and cut off the material when guiding that ahead in between the tools. In order not to stop the material just when cut¬ ting off operation the periphery speed of the disks must be accor¬ ding to the speed of the strip. It will result in a high operating noise when the cutting tools meet the material surface just before the cutting operation. The cut off pieces leave the cutter in a high speed and big problems are to noiseless catch them up. The length of the cut off material is principally determined by the distance between the cutting tools on the disk periphery and is therefore not so very easy to vary. Nowadays it is more common immediately to chop waste strips to handy pieces for charging furnaces for making new material instead of coiling them. Pieces of a length of around one decimeter are common when chopping to scrap. On the other hand when using the material for further manufacturing operations is often a claim to use shears having big capacity especially if the cutting length is narrow.

THE INUENTION

Surprisingly it has appeared a way to make rather noiseless operating shears having big capacity for transversely cutting strips and bars to short pieces of variable as well as exact lengths. The cutting operation will be carried out between disk- shaped cutting tools, the center cutting tool is fixed or rotating round a shaft, the others, two to four, are surrounding the center cutting tool in an annular path.

The material of big length, the strips or bars, is guided transversely, without any movement sideways, ahead in between the center cutting tool and one of the planetary cutting tools, that is just in time to pass the cutting station. After the cutting opera- tion the planetary tool pass by the strip to permit it to be fed one cutting length ahead before the next planetary cutting tool will be in cutting position.

SUBSTITUTE SHEET

The invention will be described more precisely in the en¬ closed claims, in a more detailed description below and by help of drawings enclosed on which the shears are shown, figure 1 from the front side, figure 2 sideways and figure 3 from above.

To show the bearings of some rotating means more exac ly these bearing means have been drawn in cross sections,

CLOSER DESCRIPTION OF THE IMENTION

The dividing disk shears ,1, will preferably be built up on a stand ,9. R center shaft ,3, is joined to this. The center shaft ,3, may be fixed or be rotated by a center cutting tool engine ,5, sometimes by way of a gear and will be fed through a feeder ,6. Rt one end of the center shaft ,3, a center cutting tool ,2, is fixed. Sometimes it is necessary to vary the speed of the engine ,5, to get the cutting speed to harmonize to the speed of the fed strip or bar ,4. In an annular path round the center cutting tool ,2, are moving a number of disk shaped cutting tools, preferably two to four ones, here called planetary cutting tools ,12, ju3t similar to the center cutting tool ,2. The planetary cutting tools ,12, and the center cutting tool ,2, is overlapping each other a little bit. The clearance between the center cutting tool ,2, and the planetary cutting tools ,9, shall be adjusted in such a way, that the cut¬ ting operation will be carried out in a correct way, when the strip ,4, is cut off to pieces ,8. The planetary cutting tools ,9, are joined to the ends of shafts parallel to the center shaft ,3, and are mounted to the side of a ring ,14. The ring, 14, rotates in an annular path round the center shaft ,3, and is fixed to spokes ,13, which are pivoted in the center shaft ,3, or fixed to a cone also pivoted in the center shaft ,3. The ring ,14, is spun round by a detached engine, the planetary cutting tool engine ,11, by way of for instance transmission belts ,10, and drives the planetary cut- ting tools ,14, round the center cutting tool ,2. The* rotation di¬ rection of the ring ,14, shall be contrary to that of the center- cutting tool ,2, if this is rotated. The strip ,4, for cutting to pieces ,8, is led by a fixed guide ,9, in a transversely angle in between the periphery of the center cutting tool ,2, and the insi e of the ring ,14, by the cutting sta ion. Uhen the ring ,14, rotates with help of the planetary cutting tool engine ,11, the strip ,4, will be cut off at the cutting station by the in turn being plane¬ tary cutting tool ,12, and the center cutting tool ,2. Then the planetary cutting tool ,12, in question continue its course round the center cutting tool ,2. Hereby the strip ,4, allows to be gui¬ ded ahead again in between the center cutting tool ,2, and the ring ,14, to settled length and then again be cut off by the center cut-

ing tool ,2, and the following planetary cut ing tool ,12. If the guide directs the material ahead at right angle to the plane surfa¬ ces of the cutting tools ,2 and 12, the cut will be in a right angel to the longitudin l direction of the strip ,4. That wi ll how¬ ever cause the strip ,4, to be stopped for a moment and that is sometimes disturbing. If the guide is directed a little bit awry to the pl ne of the surface of the tools ,2 and 12, the cutting sur¬ face will also be awry compared to the longitudinal direction of the strip ,4. In this case the strip ,4, will continue without any interruption even during the cutting operation. The cutting length is determined by the way the strip ,4, is moved ahead in between the center cutting tool ,2, and the ring ,14, before the next cut¬ ting operation. That in turn of course depends on the speed of the strip ,4, number of planetary cutting tools ,12, and the rotating speed of the ring ,14, where the movement allows to be continuous or intermittent, In other words it is possible to direct the divi¬ ding shears from chopping for instance to scrap to cutting off bars of rather big length. To increase the possibility of gripping when cutting it is favorably having the planetary cutting tools , 2, rotate even between the cutting operations. To get that it is pos¬ sible to use an already known holdfast coupling between the center cutting tool ,2, and the planetary cutting tool ,14, for instance a rubber disk mounted on the center cutting tool ,2. This is aimed to touch the planetary cutting tools ,12, and get them to rotate with a speed just similar to the center cutting tool ,2.

SUBSTITUTESHEET