Volvo patented a safety-belt design, then let other car makers use it without payment. Why?

Sam explores the geometry behind the three-point belt, the problem of making protection easy to use, and Australia's role in turning a useful invention into an everyday habit. The memorable takeaway: a safety design can become more valuable when it stops being exclusive.

Independent educational history; not sponsored by Volvo.

Sources:

Volvo Group, The three-point safety belt (design introduced 1959; free industry use):

https://www.volvogroup.com/en/about-us/heritage/three-point-safety-belt.html

Nils Ivar Bohlin, US patent 3,043,625 (original description; US grant 1962, not 1959):

https://patents.google.com/patent/US3043625A/en

Nils Bohlin, Fifteen Years with the Three-Point Safety Belt, Melbourne conference, 1977 (continued development; 1973 retractor belt):

https://developer.volvocars.com/assets/eva/1970-1979/Fifteen_years_with_the_three_point_safety_belt_Bohlin_N_1977_Melbourne.pdf

Transport Accident Commission, 40 years of seatbelts saving lives in Victoria (1970 law and historical road toll):

https://www.tac.vic.gov.au/about-the-tac/media-room/news-and-events/2010-media-releases/40-years-of-seatbelts-saving-lives-in-victoria

NHTSA, Seat Belt Safety (belt placement, airbags and front-seat passenger-car risk reduction):

https://www.nhtsa.gov/vehicle-safety/seat-belts