US Patent 7162778 Mask strap adjuster

A mask strap adjuster attaches a strap with right triangular ribs to a mask, allows the strap to be tightened by pulling the strap and comprises a base, a cover and a connector. The base has two corresponding moveable caps. Each cap has two nubs. The cover is mounted on the base and has a pawl and two nubs. The pawl engages the ribs on the strap to allow the strap to be tightened by simply pulling the strap. The nubs of the cover are pressed selectively by the nubs on the caps and press the cover away from the base and the pawl away from the ribs to loosen the strap. The cover and the base can be short.