Patents.
3,341,331; 3,341,332; 3,342,595; 3,342,602; 3,348,093; 3,350,506; 3,362,820; 3,362,823; 3,362,826; 3,363,099; 3,364,020; 3,364,021; 3,365,324; 3,365,579; 3,366,792; 3,367,791; 3,382,454; 3,383,622; 3,383,977; 3,388,343; 3,389,266; 3,389,632; 3,390,933; 3,390,606; 3,392,353; 3,393,033; 3,393,954; 3,393,957; 3,397,022; 3,397,313; 3,399,012; 3,398,669; 3,399,590; 3,401,232; 3,401,262; 3,401,263; 3,401,595; 3,402,000; 3,402,292; 3,402,298; 3,402,367; 3,402,364; 3,402,365; 3,402,366; 3,402,631; 3,402,634; 3,402,978; 3,403,955; 3,403,956; 3,404,270; 3,404,278; 3,404,281; 3,404,349; 3,404,350; 3,404,351; 3,404,352; 3,304,934; 3,405,271; 3,405,272; 3,405,273; 3,405,314; 3,405,993; 3,406,294; 3,406,315; 3,407,297; 3,408,135; 3,408,143; 3,409,346; 3,409,369; 3,409,371; 3,409,769; 3,409,773; 3,410,626; 3,410,641; 3,411,012; 3,413,468; 3,411,010; 3,411,011; 3,415,592; 3,419,706;