6 ▁A ▁– ▁" P neum atic ▁Action ▁for ▁P ian os " ▁▁ 1 9 1 7 : ▁US ▁ 1 3 4 4 5 7 4 ▁A ▁– ▁" Music - R oll - Cont rolling - Me chan ism " ▁▁ 1 9 1 8 : ▁US ▁ 1 3 8 9 2 9 0 ▁A ▁– ▁" P iano ▁Action " ▁▁ 1 9 2 1 : ▁US ▁ 1 4 4 4 3 6 4 ▁A ▁– ▁" Autom atic ▁Music - R oll ▁Car rier ▁and ▁Cent ering ▁Device ▁for ▁P neum atic ▁Musical ▁Inst ru ments " ▁▁ 1 9 2 2 : ▁US ▁ 1 5 7 4 8 6 3 ▁A ▁– ▁" String ▁Pl ate ▁for ▁Gr ands ▁P ian os " ▁▁ 1 9 2 5 : ▁US ▁ 1 6 8 6 7 2 6 ▁A ▁– ▁" Gr and ▁P iano " ▁( frame ▁construction ) ▁▁ 1 9 2 6 : ▁US ▁ 1 1 7 4 8 0 7 ▁A ▁– ▁" String ▁Pl ate " ▁( string ▁mount ing ▁construction ) ▁▁ ▁Ass ign ments ▁to ▁Stra ube ▁▁ 1 9 2 0 : ▁US ▁ 1 3 3 5 4 7 6 ▁A ▁– ▁assigned ▁to ▁Stra ube ▁P iano ▁Company ▁▁ 1 9 2 0 : ▁US ▁ 1 3 4 4 5 7 4 ▁A ▁– ▁assigned ▁to ▁Stra ube ▁P iano ▁Company ▁▁ 1 9 2 1 : ▁US ▁ 1 3 8