If you read to the end of the patent you get this:

Lastly, it should be noted that because pulling alternately on one chain and then the other resembles in some measure the movements one would use to swing from vines in a dense jungle forest, the swinging method of the present invention may be referred to by the present inventor and his sister as “Tarzan” swinging. The user may even choose to produce a Tarzan-type yell while swinging in the manner described, which more accurately replicates swinging on vines in a dense jungle forest. Actual jungle forestry is not required.

I’m so glad I’m not an American. Our government may lose billions of dollars through sponsorship scandals, but at least we’re not paying patent clerks to evaluate and approve this sort of nonsense!!1