Variable torque drive

A safety belt reel comprising a coil spring, a shaft on which a safety belt is stored and a variable torque device coupling said spring to said shaft;

• said variable torque device including at least one spiral body, driven means coupled to said shaft and driveably engaged with said body, slotted support means, said spiral body being mounted for translational movement in said slotted support means, which translational movement takes place when said spring is wound or unwound by withdrawal and retraction of said belt, said translational movement causing a change in the radius of action of a couple acting between said spring and said shaft whereby the output torque of said device is varied to adjust the force exerted on said belt.