1. Key.
 2. Wippen.
 3. Jack.
 4. Escapement lever.
 5. Hammer-shank.
 6. Hammer-butt notch.
 7. Hammer-head.
 8. Jack regulating button.
 9. Regulating button to limit rise of escapement lever.
10. Hammer-butt.
11. Check.

12. Molded tail of hammer-head to engage with check.
13. Capstan-screw connecting key and wippen.
14. Action-rails.
15. Damper-head.
16. Damper-operating device.
17. Device to limit travel of jack.
18. Regulating device for escapement lever.
19. Springs (2) for escapement lever and jack.
20. String.
21. Flange.