Knob design patent #39,941 , escutcheon design patent #38,940 by E. T. Schoonmaker. Several variations made. shown in 1901 Sargent catalog page 1-O and 1902 Sargent Book of Designs page 7, 1910 catalog page 30. Pictured are the entry and passage size knobs. Note the difference in knob construction. Click on each photo below to view additional images and information.