Abstract: A dual spool retractor structure wherein one of the spools is prevented from retraction until a predetermined amount of retraction occurs in the other of the spools.

Abstract: A continuous loop slip tongue element having an integral channel housing portion which is provided with a seat belt webbing aperture having a transverse lock buttress edge portion. A round bar element is rollably mounted within the channel housing across the seat belt webbing aperture and has a seat belt webbing slot therethrough. A seat belt webbing is freely positioned through the housing seat belt webbing aperture to slidably pass through the round bar seat belt webbing slot so that the continuous loop slip tongue element is freely movable along the seat belt webbing until the slip tongue element is moved to its operative use position in engagement with a buckle assembly which causes the webbing to reverse itself in direction. This action of the webbing moves and rotates the round bar element to a lockably stressed position within the channel housing so as to lockably retain the seat belt webbing against the lock buttress edge portion defined by the channel housing aperture.