Buckle4150464, filed August 10, 1977; and John A. Bakker and David C. Boyer, inventors of U.S. Patent 4171555, filed May 1, 1978. Both patents are held by the Illinois Tool Works, Inc. of Chicago, Illinois.
The Tracy patent (see Fig. 1) covers the actual locking buckle with the bendable locking arms on the clasp, and the grooved slot in the receptacle. The Bakker, Boyer patent (see Fig. 2) covers the means by which the strapping is locked and secured.
I use these buckles all the time camping and hiking, and I always marvel at their utility and seeming simplicity. In recent years they’ve become the standard means to lock down the rain fly on tents, which is such a good idea that I can’t believe someone didn’t think of using them for that purpose sooner.
Fig. 1. Patent 4150464.
Fig. 2. Patent 4171555.