Tension Resonator (was Re: Soundboard Installation & MC)

[Delwin D Fandrich]

----- Original Message -----
From: "Robin Hufford" <hufford1@airmail.net>
To: <pianotech@ptg.org>
Sent: April 30, 2002 4:04 AM
Subject: Re: Tension Resonator (was Re: Soundboard Installation & MC)


> > >
> > >1.  A symmetrically shaped grand piano.
> > >2.  Inner and outer rims are separate with a clearance between them and
> > >both are connected to a bottom board so that the inner rim 'is isolated
> > >from the outer rim and the vibrating capacity of the sounding-board is
not
> > >in any way interfered with'.
> > >3.  The tension resonator is attached to the inner rim and the intent
was
> > >that tension be applied to the rods so that 'every portion of the rim
and
> > >its corresponding section of sounding-board can be compressed and
> > >regulated at will'.
> > >
> > >There are various other claims as well.
> > >
> > >I far as I can tell the 'tension resonator' was the only part of this
> > >patent that M & H adopted.
>
> This I wholeheartedly agree with.  The operation of an actual "centripital
tension
> resonator" as described in your post of course would induce and maintain
crown
> and could be most interesting.  .
>

Only if one were able to keep adjusting the tension rods over the years to
compensate for the inevitable wood creep and somehow prevent the ribs from
distorting under load as the string load presses down on the bridges and the
ribs bow upwards between the bridges and the rim. (For an illustration refer
back to one of my drawings in the Journal which shows this effect.) No
matter how you slice it up, this ain't going to work in the real world.

Del