Airbag deployment velocity sensor

An airbag module (20) utilizes tape dispensing cartridges (40; 94; 138). A tape end extends from each cartridge to the inside surface of an airbag (22). As the airbag inflates, tape (36) is drawn from the tape cartridges as the tapes are drawn along with the deploying airbag. The rate at which tape is withdrawn from the cartridges (40; 94; 138) is measured by sensible indicia of a magnetic or optical nature positioned on the tape (36) and drawn past a sensor (44; 106) contained within the tape cartridge. The markings on the tape can be nonuniform along the length of the tape. A tape storage area outlet (60) and a cartridge outlet (64) are each formed by two relatively large radius corners. A seal (92) is attached to the tape and the cartridge (40; 94; 138) to prevent the ingress of contaminants. As the airbag (22) withdraws tape(36) from the cartridges, the seal (92) is unseated.