Whippen Assembly

The Whippen Assembly - where do they come up with these names?!?  Actually, the grouping of parts commonly referred to as the 'whippen assembly' is 3 separate groupings: Whippen; Repetition Mechanism; and the Jack & Let-Off Button.  

We'll go over each area of the whippen assembly in the next couple of weeks. Below are pictures of both a wooden and a composite whippen assembly on grand pianos.  You can see they are generally configured the same, with design differences specific to the manufacturer:

Traditional Wooden Whippen Assembly

Composite Whippen Assembly

You can readily see the whippen assembly is located directly underneath the hammer shank, and over the top of the key stick.  The whippen assembly transmits the motion of the key to the hammer, which in turn strikes the string to produce the musical sound.

The whippen, is the lower half of the assembly and is in direct contact with the key.  

• 1. Heel
• 2. Heel Cushion
• 3. Body
• 4. Flange
• 5. Flange Rail 
• 6. Hammer Shank Rest Post
• 7. Rest Cushion
• 8. Jack Flange
• 9. Spoon

Specifically, it works like this:  the Heel (1) rests on the capstan screw which is attached to the key.  When the key is depressed, the whippen is set into motion by the capstan screw pushing upward on the Heel Cushion (2) causing the Whippen Body (3) to move.  The body rotates on the Flange (4) which is supported by and attached to the Flange Rail (5).  The Hammer Shank Rest (6) is located at the back of the whippen directly under the hammer shank and topped with the Rest Cushion (7), a felt cushion on which the hammer shank rests when not in motion.  The Jack Flange (8) is built into the opposite end of the whippen to position the jack and allow it to rotate.  The Spoon (9) supports the jack in the proper position.

Next week we'll see how the remaining two parts of the Whippen Assembly contribute to the overall movement.

"The Disclaimer" - Technical Tuesdays are intended to give folks who are curious about pianos a bit more understanding of all those technical terms thrown about by piano technicians.  This is not intended for super-in-depth technical analysis, nor micro measurements; just general knowledge for those who are interested in how a piano works.