A DEVICE FOR CUTTING PLYWOOD VENEER

Abstract: The invention concerns a veneer cutter for cutting off the faulty spots, and for cutting the veneer into sheets at certain intervals. The cutter is furnished with rotatable blade, which consists of two independently controllable sections.

Description: A device for cutting plywood veneer The object of the invention is a device for cutting ply- wood veneer. The device is intended for cutting the veneer web issuing forth from a plywood lathe. The cutting is executed either so that the faulty spots are cut off or the veneer web is cut into sheets o certain width at set intervals. The device is especially intended for a veneer cutting application in which the veneer web cut off a log is slit into two parts in the longitudinal direction, i.e. in the direction of motion of the veneer web in so far as the web has faulty spots. The slitting is normally executed essentially along the middle of the web. Following the implementation of this method, the faults are removed independently from either part of the veneer web, whereas the sound part of the web is cut to set widths along the entire web without slitting it. While the said method does save web, because faulty spots seldom extend very far across the web, it also imposes great demands on the cutting apparatus. In applications of this method it is known for more than one slitter to be used; that is to say, two narrow slitters are used for cutting off the faulty spots in the two halves of the web and one full-size slitter is used for cross cutting comp¬ lete web sections. The invention that is the subject of this application brings about an essential improvement to the said problem in that the device in accordance with the invention makes it possible to execute both the cutting off of faulty spots in the web halves as well as the cutting into set widths of complete web sections. The device in accordance with the invention is based on what may be called the technique of a rotary-blade cutter which embodies a cutting blade reaching across the web to be cut, the said cutting blade lending itself to be rotated in a con¬ trolled manner into cutting contact with a selected cut¬ ting point on the veneer web. The rotary motion of the said blade has been selected to be such that it complies with the forward motion of the veneer web whereupon the blade does not cause the veneer web to be arrested on being cut. Usually this type of a cutting blade works in unison with a roller supporting the veneer web or with a correspon¬ ding opposing organ against which the blade is forced in order for the cutting action to be executed. The blade can be made to sufficiently massive for the cutting oper- ation to occur successfully. The said massiveness of the blade may be achieved, for instance, by making the blade shaft sufficiently solid. Alternatively, the cutting ap¬ paratus may embody an abutting organ on the side opposite to the blade, the said abutting organ providing the blade with support for the cutting operation to be executed. The stiffness of a structurally light blade can be in¬ creased by subjecting the blade shaft to tensile stress when in use. In accordance with the invention, the said blade element is divided into two consecutive sections along its shaft, the rotational position of the said elements being such that they can be controlled independently. The invention is described by means of the appended dra¬ wing. The drawing shows the blade arrangement in accordance with the invention, the said arrangement embodying a shaft 1 reaching across the entire veneer web that is to be cut and the two blade elements 2 and 2 ' ' supported by it. The blade elements may be rotated independently on the shaft 1 and they are provided with their own rotating apparatus. When the slit veneer web passes underneath the blade structure 2, and it contains random faults on one half or the other or simultaneously on both halves, the blade elements 2 ' and 2 ' ' execute cutting operations on the web halves independently on one another in order to remove faulty spots from their respective halves. Once the peeling of the veneer web has proceeded onto the sound part of the peeled log, the slitting of the veneer web coming to the slitter is discontinued and the control for the blade elements 2 ' and 2 ' ' are combined to obey the same command, this command usually being to cut the veneer web into sheets of certain width. When executing this function, the blade elements 2' and 2" are, of course, angularly in unison with one another and form a contiguous blade reaching across the veneer web. The said joint-function model may include situations in which the veneer web contains faulty spots that need to be removed. When this is the case, the faulty spots are cut off in strips extending across the entire veneer web by the blade elements 2 ' and 2 ' ' working in unison. In deviation from the above execution model, where the blade elements 2 ' and 2 ' ' are composed of two blades 2'a, 2'b, and correspondingly 2 / a , 2' , b, the blade elements may consist more blades; e.g. four blades positioned at even angles on a shaft. Even one blade per blade element 2 ' and 2 ' ' forms a functioning solution.

Claims: Claims : 1. A device for cutting a veneer web into sheets of cer¬ tain width and/or for removing faulty spots by means of a cutting blade (2) that can be rotated in a controlled manner on a shaft (1) , the said blade (2) traversing es¬ sentially crosswise across the veneer web and lending itself to be rotated into cutting contact with the veneer web to execute a crosswise cut so that the blade complies with the motion of the veneer web, characterized in that the blade (2) is formed of two independently controllable sections (2', 2") along the shaft (1). 2. A device in accordance with claim 1, characterized in that each of the blade sections (2', 2 ,, ) extends to half-way across the veneer web to be cut. 3. A device in accordance with claim 1 or 2, character¬ ized in that both of the blade sections contain two blad- es (2'a, 2'b; 2"a, 2"b) oppositely located with respect to the shaft (1) . 4. A device in accordance with any of claims 1 to 3, cha¬ racterized in that the blade (2) is arranged to cut the veneer against a supporting roller while at the same time behind abutting on a supporting organ. 5. A device in accordance with claim 4, characterized in that the blade shaft (1) is under tensile stress. 6. A device in accordance with any of claims 1 to 3, cha¬ racterized in that the blade (2) is mounted onto a mass¬ ive shaft (1) that is solid enough to provide the blade with sufficient support for the execution of the veneer cutting operation.

Inventors: SINTONEN KARI, SINTONEN, KARI
Applicants: RAUTE OY
Application year: 1992
Main classification: B27L5
IPC codes: B26D1, B26D11, B27C1, B27G1, B27L5