Method and apparatus for rounding the backs of book blocks

In apparatus for shaping the backs of book blocks, the shaping apparatus being associated with a transport system including continuously moving clamps which engage and move a book block along a path, the shaping apparatus further having back-rounding means including rounding rollers which act on both sides of the book block once it has been released by a transport system clamp, the rounding rollers applying pressure to the book block and being caused to exert a rotational force on the block while the pressure is applied, the improvement comprising;

• said clamps each comprising a pair of oppositely acting jaws, the clamp jaws each being provided with an aperture sized and shaped to permit the passage of a said rounding roller therethrough;
• means for causing said shaping apparatus to move in a first direction in synchronism with the motion of said clamps along at least a portion of the path of book block movement established by the transport system;
• and
• means for imparting reciprocal motion to said rounding rollers in a second direction generally transverse to said first direction whereby said rounding rollers may be extended through said apertures in said jaws to engage the book block and may be retracted from said apertures.