Action of the Square Piano
A. Action Frame. B's Indicate the Cushions, or Bushing, of felt, cloth or leather. C. Balance Rail. D. Balance Pin. Round. E. Mortised Cap for Balance Pin. Bushed. F. Key. G. Lead. H. Back Check. I. Bottom or Key Rocker. J. Bottom Screws; used to regulate height of Jack. K. Jack. L. Jack Spring; concealed under Bottom. M. Center Pin to Jack. N. Hammer Rail. O. Regulating Screw. P. Regulating Button. Q. Flange Rail. R. Flange. Split. S. Flange Rail Screw. T. Flange Screw, to regulate jaws of flange. U. Hammer Butt. V. Center Pin. W. Hammer Stem or Shank. X. Hammer Head. Y. Hammer Felt. Treble hammers sometimes capped with buckskin in old instruments.
Upright Piano Action
Ky, is the Key in its resting position. c, wherever found, represents a cushion of felt or soft leather upon which the different parts of the action rest or come in contact with each other. Their purpose, as is readily seen, is that of rendering the action noiseless and easy of operation. Bnc R, shows the end of the balance rail, extending the entire length of the keyboard. B P, is the balance pin. This is a perfectly round pin driven firmly in the balance rail. The bottom of the hole in the key fits closely around the balance pin; at the top, it is the shape of a mortise, parallel with the key, which allows the key to move only in the direction intended. The mortise in the wooden cap on top of the key at this point is lined with bushing cloth which holds the key in position laterally, and prevents looseness and rattling, yet allows the key to move easily.
Action of the Grand Piano
1. Indicates the felt, cloth or leather, upon which the various parts of the action rest, or fall noiselessly. 2. Key. 3. Bottom; sometimes called Key Rocker. 4. Extension; split at lower end to receive center pin in Bottom. 5. Wippen Support. 6. Jack. 7. Jack Spring. 8. Flange and Regulating Rail. 9. Regulating Screw, Button and Cushion. 10. Escapement Lever. 11. Regulating Screw in Hammer Flange, for Escapement Lever. 12. Check Wire, for Escapement Lever. 13. Screw to regulate fall of Escapement Lever. 14. Lever Flange, screwed to Flange Rail. 15. Hammer Shank. 16. Hammer. 17. Back Check. 18. Damper Lever, leaded. 19. Damper Wire, screwed into upright. 20. Damper Wire Guide, fastened to Sound-Board. 21. Damper Head and Felt. 0. Center Pins. Holes lined with Bushing Cloth.