[BC] Gray Tone Arms Patent link

[Don Worsham]

> 
> >  Re: Gray Tone Arms
> > The patent is owned by the Columbia Broadcasting System.
> 
> And expired a few decades ago!  Interesting reading, though.
> 
> - JimT
> 
> 
>
A number of tonearms use (used) fluid dampening. This patent and the patent for the 
Gray 212/216 refer to a number of other patents, some to the shape of the arm and 
others to fluids.

The patent specifies the silicone "cst" rating for arm dampening. In this case 2,000 
cst (thin as pancake syrup) to 100,000 cst (hot tar!!!). I once had a 108 arm, which I 
am trying to replace, and as I recall the dampening fluid was toward the thick end of 
this range.  




"Don Worsham" media at gte.net