Hub device

Hub device arrangement for a pair of saw blades, including a first blade, arranged to rotate about a rotational axis in a first direction, and a second blade, arranged to rotate about the rotational axis in a second direction opposite to said first direction, each of the blades including a blade body and cutting elements, respectively along a periphery of each of the blade bodies, the cutting elements being arranged to run close to and in parallel with each other during rotation on a distance determined by a spacer on at least one of the blade bodies, wherein the first saw blade includes a back side and an opposite front side, intended to be turned towards a back side of the second saw blade, that has an opposite front side too, the hub device arrangement comprising:

• a first blade adapter, including a support surface for the back side of the first saw blade,
• a centering flange, protruding from the support surface for a centering hole in the first saw blade;
• protruding drive pegs to engage drive peg notches, which surround the centering hole of the first saw blade;
• a second blade adapter, including a support surface for the back side of the second saw blade and a central fastener for a blade lock, arranged to secure both of the first and second saw blades, the support surface of the second blade adapter, around the rotational axis, including at least three ridges for engagement with corresponding notches in the second saw blade, the ridges having a height that exceeds a thickness of the main blade of the second saw blade, and the blade lock including a circumferential ring surface facing the support surface of the second blade adapter, wherein the blade lock is arranged to when locked, have its ring surface abutting the ridges of the second blade adapter, so that the second blade gets a limited axial mobility against the support surface of the second blade adapter, said mobility being determined by the difference between the height of the ridges and the thickness of the blade body of the second saw blade.