Dampp-Chaser Patent #6,133,519

[John Formsma]

Paul,

I looked at this last night. (www.uspto.gov) It appears to be the only
patent for a cover to be used in conjunction with a DC system. I
didn't look everywhere, but this was one of the three patents I found
for Dampp-Chaser Corp.

Anyway, what this appears to be talking about is the older way of
doing it with the mylar type plastic material. I think I installed
only one of those, as it was right around the time that I started
working full-time as a piano tech.

The undercover in use now is speaker fabric.

There is a possibility that there might be a patent pending. Maybe
someone could contact Dampp-Chaser and find out. Or maybe someone from
there will comment here on the list.

There are a number of us who want to abide by the law, and it would be
helpful to know exactly what that is.

JF

P.S. After reading the patent lingo, one thing I hope I never have to
become is a patent lawyer. Ugh!  :-)  No offense to any of you who
like that kind of thing.

On 4/30/07, paul bruesch <tunergeek at gmail.com> wrote:
> I found the Dampp-Chaser's patent online:
> http://www.freepatentsonline.com/6133519.pdf
> (you might have to create an account to look at the pdf, for some darned
> reason)
>
> According to the abstract, the under/back cover patent is for a "...moisture
> impervious aperture free sheet...".  In the detail of the patent write-up,
> under "Background of the Invention" it specifies "MYLAR or felt" (caps
> theirs) "... having a plurality of apertures or holes..." (which, to my
> mind, contradicts the abstract portion... but then again I'm not a lawyer.)
>
> So, what sort of fabric/material is Dampp-Chaser's under/back cover made
> of?  I'm not a rocket scientist, nor even a acoustic engineer, heck, I'm not
> even an RPT, but the idea of Mylar back/under cover on a piano sounds to me
> like it would sound a bit bizarre. Wouldn't it?? And wouldn't felt mute and
> muffle the sound?  (see previous disclaimers regarding my qualifications)
>
> I wonder what a "plurality of apertures or holes" means... several holes
> and/or apertures in the cover, or is that phrase intended to include an open
> weave like speaker cloth, being what it sounds like many techs are using.
> An open weave certainly has a "plurality of holes," but it would make a lot
> more better sense to say "open weave fabric."
>
> Please understand that I'm not trying to get around anyone's patent, or
> infringe on same... when the time comes I'll order the DC cover simply for
> the convenience of it, if for no other reason. My curiosity is piqued about
> this patent for a new way to use a piece of cloth... and I'd just like to
> understand it better. Judging from the amount of traffic generated by this
> topic, I don't think I'm alone.
>
> Paul Bruesch
> Computer Geek and PTG Associate, who typically plays by the rules but wants
> to understand them. And I don't run with scissors.
>
>
>