Keywords: Rimbaultp191fig2.svg illustration captioned Wornum's Unique Action Edward F Rimbault The Pianoforte Its Origin Progress and Construction Robert Cocks Co London 1860 p 191 ~ 1860 unsigned not credited many of the drawings appear in the Penny Cyclopedia article Piano-forte published 1840 http //www archive org/details/pianoforteitsori00rimbuoft a key b hopper c string d hammer rail e hammer f damper and wire g damper rail h ruler i i springs PD-Art Musical instruments schemes Musical instruments technical diagrams Piano action SVG music |