Annular saw blade and annular saw

An annular saw, comprising an annular saw blade, which is rotatable about an imaginary center axis, wherein said annular saw blade is driven by a drive shaft having an axis which is generally parallel to the center axis of said saw blade and located between the annular saw blade and the center axis of said saw blade;

• the drive shaft having mounted thereon two drive rollers having the surfaces which are adjacent to one another beveled at a predetermined angle so that the rollers provide first and second drive surfaces which between them form a wedge-shaped groove, in operation at least one of said drive rollers automatically movable axially of said drive shaft with respect to the other roller so as to compensate for wear of said roller or said blade;
• the inner edge portion of the saw blade being beveled in a corresponding manner, the bevel angle being at least substantially the same as for the drive rollers, to provide third and fourth drive surfaces cooperating with the drive surfaces of said drive rollers to rotate said blade about its imaginary center axis;
• the outer edge portion of the saw blade providing a cutting surface;
• a web connecting the inner edge portion and the outer edge portion of said blade being provided with at least one annular groove on at least one side thereof, said at least one annular groove being radially displaced, along a radius from said imaginary center axis, from said third and fourth drive surfaces;
• at least two first running rollers being provided on the side of said saw blade which faces said at least one annular groove, said first running rollers each being provided with a flange engaging said groove;
• at least two second running rollers being provided on the side of said saw blade opposite said first running roller, said first running rollers and said second running rollers in combination forming respective pairs of opposed running rollers for supporting the saw blade, so that the saw blade is held firmly between the two drive rollers and said pairs of opposed running rollers, said drive rollers and said pairs or opposed rollers disposed proximate said saw blade in an area of less than one half of the circumference of the blade.

An annular saw, comprising an annular saw blade, which is rotatable about an imaginary center axis, wherein said annular saw blade is driven by a drive shaft which is parallel to the center axis of said saw blade and located between the annular saw blade and the center axis of said saw blade;

• the drive shaft having mounted thereon a first drive roller and a second drive roller of which the surfaces adjacent to one another are beveled at a predetermined bevel angle so that the rollers comprise drive surfaces which between them form a wedge-shaped groove;
• the two lateral surfaces of the saw blade are beveled in a corresponding manner within a region close to the inner edge of the saw blade, the bevel angle being the same as for the drive rollers;
• the beveled edge portion of the annular saw blade being clamped between the beveled drive surfaces of said first and second drive rollers in the wedge-shaped groove;
• said first drive roller being pressed toward said second drive roller, clamping the beveled edge portion of the saw blade between the beveled drive surfaces of said first and second drive rollers, by a helical spring provided between the remote surface of said first drive roller and a member which is fixed in relation to the drive shaft;
• and said spring is secured through its end portions to said first drive roller and said fixed member, respectively, such that the spring is stretched if the drive shaft rotates in the direction of the saw blade relative to said first drive roller.

An annular saw comprising an annular saw blade which is adapted to rotate about an imaginary center axis by being driven by a drive shaft which is parallel to said center axis and located between the annular saw blade and its center, two drive rollers mounted on the drive shaft, the surfaces of said drive rollers adjacent to one another being beveled at a predetermined bevel angle to define a wedge-shaped groove, the two lateral surfaces of the saw blade being beveled in a corresponding manner proximate the inner edge of the saw blade;

• at least one annular groove being provided on at least one side of the web of the saw blade;
• two first running rollers provided on the side of the saw blade with the annular groove, said first running rollers being provided with a flange engaging the groove;
• two second running rollers on the opposite side of the saw blade from said first running rollers, respectively, said first running rollers and said second running rollers in combination forming two pairs of opposed running rollers for supporting the saw blade;
• and means for automatically pressing the beveled driving rollers relative to each other to clamp the beveled inner edge portion of the saw blade between them, so that the saw blade is held firmly between the two drive rollers and driven thereby;
• the axis of rotation of the drive rollers being perpendicular to the saw blade and located between said opposed pairs of running rollers, said driving rollers and said two pairs of opposed running rollers disposed proximate said saw blade in an area of less than one half of the circumference of the blade.