Patents by G. Spencer-Brown

Lift Control System, UK1006018, 1965
	18 pages, 34 claims. [PDF, 12.5MB]

Lift Control Circuit Arrangement, UK1006019, 1965
	5 pages, 10 claims. [PDF, 3.1MB]

Apparatus for Playing a Board Game, WO8902772, 1989
	21 pages, 20 claims.