Rounded Toothed Jaws for Sheet Binding Fiber Breakage

The patent applies curvature by rounding the corner edges of the toothed jaw protrusions. Instead of sharp-edged corners that cut paper fibers, the corners are formed with rounded ridges that gradually decrease in radius toward the tip. This curved geometry allows the binding force to be distributed smoothly across the paper fibers without creating stress concentration points that would cause fiber breakage, thereby maintaining binding strength while eliminating the harmful cutting effect.

The rounded corner edges with gradually decreasing radius create a progressive deformation pattern in the paper fibers. The curvature allows the embossment to gradually set the fibers in the bound position without creating sharp stress points that would cause fiber failure. This gradual deformation makes it more difficult for the sheets to recover to their original shape, thereby maintaining bound state stability while preserving binding strength.

The rounded corner edges of the toothed jaws eliminate the sharp stress concentration that causes wrinkles and tears during the binding operation. The gradual curvature of the ridges allows the paper to deform smoothly under pressure without creating the localized stress peaks that lead to surface defects. This maintains binding operation efficiency while preventing the formation of wrinkles and tears on the sheets.