Action Analyses (was Capstan Relocation)

[Clark]

Hi,

Ron Nossaman wrote:

> [Fandrich] Grand action? I don't remember seeing one.

Poke around the Delphion Intellectual Property site at
<http://www.delphion.com>. It's more browser-friendly than the USPTO
site.

Briefly, this action has a normal key, with a back check and capstan
screw, but the wippen lacks a repetiton lever and the jack lacks a
tender. A torsion spring ties the jack to the hammer shank, attached
roughly perpendicular near the top of the jack and toward the hammer on
the shank; there is no separate jack spring. Let off is accomplished by
the older 'bumper' system, with a regulation button bearing upon a
profile set on the upright of the jack, and which lets off toward the
hammer instead of toward the flange. The integral(?) padded knuckle has
a flattened profile and on closer inspection, also has a positive stop
although which appears to engage the jack in check rather than at rest.

> There are two mechanical adjustments and one spring adjustment in the 
> action. This configuration enables a simpler, quieter, easier to 
> adjust action which stays in adjustment for longer periods of playing 
> time and with no sacrifice in performance.

	- Fandrich et al. "Action for Grand Piano", 
	  U.S. no. 4953433, 04/09/90.

(in contrast, Hickman's has three mechanical adjustments, Brown's has
two while a modern H/E usually has five - well, counted on my fingers
and not including checking, key height, dip, upstop, rail positions,
jack stop or back action)


Clark