Expander roller for webs of paper and the like

The expander roller of claim. 1, wherein said at least one groove extends from said external surface short of said peripheral surface, said at least one strip having a portion disposed between said groove and said peripheral surface and having in the radial direction of said core a thickness in the range of 2 and 6 mm.

An expander roller comprising a substantially cylindrically core having a peripheral surface;

• and an outer layer surrounding said peripheral surface and including at least one helically convoluted strip, said outer layer including a substantially cylindrical external surface having a profile composed of at least one groove provided in said at least one strip and said at least one strip having two lateral surfaces extending between said peripheral surface and said external surface, said lateral surfaces converging toward each other in a direction from, said external surface toward said peripheral surface.

An expander roller comprising a substantially cylindrical core having a peripheral surface;

• and an outer layer surrounding said peripheral surface and including at least one helically convoluted strip, said outer layer including a substantially cylindrical external surface having a profile composed of at least one helical groove and said at least one strip having two lateral surfaces extending from said external surface to said peripheral surface, said helical groove being provided in one of said lateral surfaces and extending in a direction from said external surface toward but short of said peripheral surface, said external surface having a profile composed of said at least one groove and a second helical groove substantially parallel to said at least one helical groove and extending from said external surface toward but short of the other of said lateral surfaces.

An expander roller comprising a substantially cylindrical core having a peripheral surface;

• and an outer layer surrounding said peripheral surface and including at least one helically convoluted strip, said outer layer including a substantially cylindrical external surface having a profile composed of a first groove and a second groove which is provided in said external surface and extends toward but short of said peripheral surface, said at least one strip having two lateral surfaces extending from said external surface to said peripheral surface and being spaced apart a distance of 12 to 30 mm in the axial direction of said core.

An expander roller comprising a substantially cylindrical core having a peripheral surface;

• and an outer layer surrounding said peripheral surface and including at least one helically convoluted strip, said outer layer including a substantially cylindrical external surface having a profile composed of at least one helical groove formed in said at least one strip and extending longitudinally of said at least one strip as well as from said external surface toward said peripheral surface.