IP in Everyday Life – Aircraft Seat Belts
Most of us fly frequently. But, we might not have paid attention to the most vital piece of safety equipment for a passenger; the seat belt. If you flip the receptacle portion of the belt, you will see a notice which states “Patent 5088160”.
The referred patent is assigned to Am-safe, Inc and was filed on February 5, 1990 (and has subsequently expired on February 5, 2010).
The two independent claims are as follows:
Claim 1: A webbing adjustor for adjusting and locking seat belt webbing which is anchored at one end, the webbing adjuster including a base frame, said base frame including a transverse bar stop, an elongated load bar mounted for sliding movement on said base frame toward and away from said bar stop, said load bar having an outer surface about which the webbing is wrapped in a forward direction from said anchored end, said outer surface of said load bar having a transverse substantially planar surface and a plurality of transverse rounded edge surfaces each having a radius of curvature, said rounded edge surfaces displaced from said planar surface and from each other, the position of said planar surface on said load bar relative to said bar stop being such that when the webbing is placed under tension, it is pinched over a transverse area between said planar surface and said bar stop, the webbing when placed under further tension from the anchor end is moved in the reverse direction from said pinched area and progressively frictionally gripped at each of said plurality of rounded edge surfaces, the radii of curvature of all of said rounded edge surfaces closer to the anchored end being larger than all of the rounded edge surfaces of said plurality of rounded edge surfaces closer to the pinched area of the webbing, such that the frictional gripping of the webbing is greatest near the pinched area and less near the anchored end of the webbing.
Claim 3: A webbing adjuster for seat belt webbing, which includes a base frame, an elongated load bar mounted in the base, frame by a pair of keepers for sliding movement on the base frame, each of said keepers having two spaced apart tines the inner surfaces of which are adapted to be received in transverse slots of said load bar, first to center it, and then to securely position said load bar on said bar frame, said base frame having a transverse substantially planar surface and a transverse rounded edge surface displaced therefrom, said surfaces being positioned on said load bar so as to pinch webbing wrapped around said load bar between said planar surface and said base frame and to frictionally grip the webbing at said rounded edge surface.
The complete patent document can be found here.