US Patent 1,957,994, granted May 8, 1934 to Angelo F. Eccher of San Francisco, for a wheeled machine that unrolls and spreads burlap covers over fields of mulberry trees used for silkworm culture. The cover protects the worms from weather and birds, and is later lowered so the worms spin their cocoons on the burlap, where they can be gathered easily. The scan has four sheets of drawings (11 figures) followed by the specification and ten claims.