Patents.
3,154,687; 3,176,576; 3,277,782; 3,278,749; 3,278,752; 3,276,316; 3,277,327; 3,279,307; 3,279,317; 3,279,938; 3,280,369; 3,281,253; 3,281,254; 3,281,255; 3,281,598; 3,282,149; 3,283,133; 3,283,152; 3,283,159; 3,283,202; 3,283,655; 3,284,252; 3,284,633; 3,286,581; 3,286,584; 3,287,556; 3,289,527; 3,290,147; 3,290,509; 3,290,530; 3,290,987; 3,291,601; 3,291,621; 3,291,907; 3,291,985; 3,296,368; 3,296,441; 3,296,443; 3,296,920; 3,297,875; 3,297,876; 3,297,878; 3,299,268; 3,299,271; 3,299,273; 3,299,274; 3,299,306; 3,299,768; 3,299,769; 3,299,770; 3,300,644; 3,300,653; 3,300,668; 3,301,130; 3,301,131; 3,306,157; 3,306,158; 3,306,160; 3,307,447; 3,308,230; 3,308,235; 3,308,299; 3,308,303; 3,329,499; 3,330,908; 3,343,447; 3,348,902; 3,353,439; 3,353,896; 3,355,290; 3,357,852; 3,359,125; 3,359,851; 3,359,852; 3,360,323; 3,360,324; 3,361,045; 3,364,065; 3,365,293; 3,365,296; 3,367,733; 3,369,120; 3,369,122; 3,369,446; 3,369,447; 3,370,902; 3,370,502; 3,370,903; 3,371,212; 3,371,214; 3,371,574; 3,371,978; 3,372,278; 3,372,971; 3,372,972; 3,372,973; 3,372,974; 3,373,278; 3,373,651; 3,374,044; 3,374,357; 3,374,392; 3,375,752; 3,375,754; 3,376,089; 3,376,090; 3,376,091; 3,376,381; 3,376,421; 3,376,422; 3,376,423; 3,376,453; 3,376,454; 3,377,119.