Patent ID: 6883746

Claim:
A winding apparatus for winding a web material such as paper, plastic film about a hollow core including an inner surface, said apparatus comprising: a ringed holder including an outer surface and an end surface and disposed around and coaxially with a shaft for rotation about said shaft; a ringed slide including an outer surface and fitted onto the outer surface of said holder for movement axially of said shaft; a tapered surface formed on the outer surface of said slide; a plurality of tips spaced from each other angularly around said slide and engaged with said tapered surface for movement radially of said shaft; first and second pistons disposed on opposite sides of said holder in the axial direction of said shaft and inserted into first and second bores respectively; a first flow path formed in said shaft, fluid pressure being directed into said first bore through said first flow path so that said slide can be moved axially of said shaft by said first piston, said tips being moved and expanded radially of said shaft by said tapered surface to be pressed against the inner surface of said core so as to hold said core; and a second flow path formed in said shaft independently of said first flow path, fluid pressure being directed into said second bore through said second flow path so that said second piston can be pressed against the end surface of said holder, a torque being transmitted to said holder, said slide, said tips and said core from said shaft by means of a friction generated between said second piston and said holder so that said core can be rotated by said torque.