JOHN THOMAS ADAMS
Medical Practice in Detroit, MI

4099683, Jul 11, 1978

Feb 2, 1977

5/764945

Richard C. Stouffer - Auburn Heights MI
John Adams - Grosse Pointe Woods MI

Allied Chemical Corporation - Morris Township, Morris County NJ

A62B 3502, B65H 7548

242107

A safety belt retracting mechanism having constant pull includes a rotatable spool for storing the belt inside a housing. A conventional, positive coefficient of force spring inside the housing applies a retracting force to the spool and belt as the belt is pulled by the occupant. The spring is coupled between the housing and spool through a variable gear ratio gear train having a negative coefficient of force transfer characteristic. The negative transfer characteristic of the gear train compensates for the positive characteristic of the spring to provide constant pull to the belt between fully retracted and fully protracted belt positions. Three embodiments of the invention are disclosed. In one embodiment, the changing gear ratio is produced by a pair of oppositely oriented cone gears connected respectively to the spring and to a spindle supporting the belt spool. The cone gears are coupled together with a traversing pinion that lowers the force gear ratio of the cones as the belt is protracted by the occupant.