Dual spring retractor

A seat belt retractor comprising:

• a spool on which seat belt webbing is wound, said spool being rotatable in belt withdrawal and belt retraction directions;
• first and second springs for biasing said spool in the belt retraction direction;
• means for selectively blocking the bias of said first spring from acting on the spool, said means comprising a rotatable ratchet associated with said first spring and a pawl movable between at least first and second positions, said pawl in said first position engaging said ratchet to block rotation of the ratchet in the belt retraction direction to thereby block the bias of said first spring from acting on the spool;
• a cam rotatable relative to said spool for controlling the movement of said pawl between its first and second positions;
• and
• a cam driver rotatable with said spool, said cam driver including a deflectable part which engages said cam and rotates said cam to control the position of said pawl.

A seat belt retractor comprising:

• a spool on which seat belt webbing is wound, said spool being rotatable in belt withdrawal and belt retraction directions;
• first and second spring means for biasing said spool in the belt retraction direction;
• means actuatable for selectively blocking the bias of said first spring means from acting on said spool whereby only said second spring means biases the spool in the belt retraction direction when said means is actuated;
• and
• means for deactuating said actuatable means after more than one revolution of said spool to allow said first and second spring means to bias said spool in the belt retraction direction against withdrawal of belt webbing only after more than one revolution of said spool.

A seat belt retractor comprising:

• a frame;
• a spool on which seat belt webbing is wound and which is rotatable in said frame in belt withdrawal and belt retraction directions;
• a ratchet rotatable relative to said spool;
• first and second springs biasing said spool in the belt retraction direction, said first spring acting between said ratchet and said frame, said second spring acting between said ratchet and said spool;
• a pawl having a first position blocking rotation of said ratchet in the belt retraction direction and a second position in which said pawl does not block rotation of said ratchet in the belt retraction direction;
• means biasing said pawl toward its first position;
• a cam rotatable relative to said spool and said pawl, said cam having a surface portion for moving said pawl from its first position to its second position upon rotation of said cam relative to said pawl;
• and
• a cam driver rotatable with said spool and engageable with said cam to rotate said cam relative to said pawl to effect movement of said pawl from its first position to its second position;
• said cam and pawl cooperating to block rotation of said cam in the belt retraction direction by said cam driver when said pawl is in said second position;
• said cam driver also being rotatable relative to said spool, and the retractor further including a member connected to said spool for rotation with said spool, said member being rotatable relative to said cam driver and having a portion engageable with said cam driver to rotate said cam driver.