Apparatus for winding wire on a spool

An apparatus for winding a wire onto a spool, said wire being elastic in its radial direction and having a cross-sectional shape other than substantially rectangular before said winding, said apparatus comprising:

• rotation means for rotating said spool about a longitudinal axis and for causing said wire to wind on said spool during said rotation thereof;
• at least one pressure roller mounted for reciprocal movement relative to the longitudinal axis of said spool and for rotation about an axis transverse to the direction of said reciprocal movement;
• a peripheral groove in an outer face of said roller for interacting with a previously wound coil of a layer of wire being wound on said spool and with an underlying surface of said spool or a previously wound layer of said wire so as to provide a wire shaping space having a substantially rectangular cross-sectional shape, said peripheral groove having a bottom line defining an imaginary plane intersecting the longitudinal axis of said spool at an acute angle;
• and,
• pressing means for causing said at least one pressure roller to press a portion of said wire being wound onto said spool into said wire shaping space at a pressure altering the cross-section of said wire portion from said before winding cross-sectional shape to a substantially rectangular cross-sectional shape corresponding substantially to said substantially rectangular cross-sectional shape of said wire shaping space, said wire portion being pressed by said groove at said pressure simultaneously against said previously wound coil of the layer of wire being wound on said spool and against said underlying surface of said spool or said previously wound layer of said wire so as to provide tight coils of said wire without significant space between adjacent coils.