A fastening system for a circular saw blade

Abstract: The circular saw blade (1,10) is fastened by means of a screw/screws (2,9) to a fastening flange on the turning arbor (6), to a chipping edger (3) in a hewing saw, or to a chipping cutter (8). The fastening part (5,11) of the circular saw blade (1,10) is made conical and the circular saw blade (1,10) is fastened between two corresponding conical surfaces.

Description: The present invention relates to a fastening system for a circular saw blade, in which the circular saw blade is fastened by means of a screw/screws to a chipping edger in or to a chipping cutter. In prior-art systems, the steel frame requires reinforcement, i.e. additional thickness, in order for the screw fastening to be sufficiently sturdy. In these systems it is necessary to use a plurality of countersunk screws, the opening and fastening of which in connection with servicing is cumbersome and very time-consuming. When the blade is of the same material in the area of the reinforcement, it reacts immediately to heat, which in turn causes distortions in the actual blade. The prior-art systems in which there are reinforcements are also very expensive. US-A-4984614 describes a combined saw and chipper head. The chipper body is secured to the hub of a rotatable shaft by means of bolts, and the saw blade is secured to the chipper body by means of screws through flared washers. US-A-5031364 describes a fastening system for a cutting disk, wherein the disk is fastened by means of a screw to the turning arbor. According to one embodiment, the arbor and the disk comprise a conically formed central portion for the screw. The object of the invention is to eliminate the disadvantages described above. In the fastening system according to the invention the fastening part of the circular saw blade is made conical and the circular saw blade is fastened between two corresponding conical surfaces. A blade such as this is considerably more economical to manufacture, since areas of different thickness are not necessary in it. The blade is considerably more rapid to detach and fasten in connection with servicing, since the fastening system does not require as many screws as do the prior-art systems. The blade is tightened evenly by its conical surface. The blade may even be in a plurality of segments, since owing to the cone it centers in place. The conical part also provides additional sturdiness for the blade, and it is therefore also easier to handle in connection with servicing. By using the system according to the invention, a so-called smooth frontal surface is obtained, i.e. one side of the circular saw blade is left free as far as the hub; this is required in chipping cutters and in chipping canters. The invention is characterized in that the tightening flange is tightened in place by means of screws passing through the fastening flange. In this system the tightening flange may be circular, and its tightening also does not require many screws. A further embodiment of the invention is characterized in that the cone angle is 30-60° relative to the plane of the circular saw blade. The cone angle will probably be 45°. One embodiment is further characterized in that the tightening flange is of a different material than the circular saw blade, for example of cast steel. The tightening flange is heated up considerably by friction in the frontal surface and, for example, cast steel does not become easily distorted regardless of heating up. Heat generated by friction will not react directly on the actual circular saw blade, as it does in prior-art systems. The invention is described below with the help of examples, with reference to the accompanying drawings, in which Figure 1 is a cross-sectional representation of a fastening system for a circular saw blade, Figure 2 depicts the circular saw blade belonging to the fastening system of Figure 1, Figure 3 depicts the fastening system for a circular saw blade, according to the invention, and Figure 4 depicts a circular saw blade of this fastening system. The fastening system of Figure 1 is not covered by claim 1, but is presented as useful for understanding the invention. In the fastening system shown in Figure 1, the circular saw blade 1 is fastened by means of a screw 2 so that the circular saw blade is tightened between a chipping edger 3 and a fastening flange 4. The fastening part 5 of the circular saw blade 1 has been made conical, and the tightening surfaces in the chipping edger 3 and the fastening flange 4 are corresponding conical surfaces. The tightening screw 2 tightens to the turning arbor 6, whereby the chipping edger 3 is also tightened in place by the same tightening screw. In the embodiment shown in Figure 3, the fastening flange 7 is circular, and it is tightened in place by means of screws 9 passing through a chipping cutter 8. The conical fastening part 11 of the circular saw blade is tightened between the conical surfaces in the chipping cutter 8 and the fastening flange 7. In both embodiments, the cone angle α is 45°. The detaching and fastening of the circular saw blade is easy and rapid owing to the large size and small number of the screws.

Claims: A fastening system for a circular saw blade (10), wherein the circular saw blade is fastened by means of a screw (9) to a fastening flange (8) on the turning arbor, wherein the fastening part (11) of the circular saw blade is made conical and the circular saw blade (10) is fastened between two corresponding conical surfaces one of which is provided on the fastening flange (8), characterized in that the fastening flange (8) is a chipping edger or a chipping cutter, the surface of the circular saw blade is substantially reduced to a rim portion, which rim has at its radially inner edge the conical part for being clamped from a correspondingly formed edge of a tightening flange (7) having a plurality of axially oriented threaded holes into which corresponding tightening screws are screwed which passes through the fastening flange (8) from the side opposite to the saw blade (10). A fastening system according to claim 1, characterized in that the cone angle (α) is 30-85° relative to the plane of the circular saw blade (1, 10). A fastening system according to claim 1 or 2, characterized in that the fastening flange (4, 7) is of a different material than the circular saw blade, for example of cast steel.

Inventors: RAUTIO KAUKO, RAUTIO, KAUKO
Applicants: RAUTIO KAUKO, RAUTIO, KAUKO
Application year: 1993
Main classification: B27B5
IPC codes: B27B33, B27B5, B23D61