[78-L] Approximating 78s age by physical characteristics

Michael Shoshani michael.shoshani at gmail.com
Mon Mar 4 05:23:27 PST 2013


There are a lot of patents on the laminated record idea, including a 
couple filed by Herbert Berliner in 1908. But here's one out of many 
that caught my attention some time ago.

This patent was filed in 1906 and granted in 1912. It was filed by 
Thomas A. MacDonald of American Graphophone, to whom the patent was 
assigned. It's a patent for RECYCLING old record stock!!!

Basically, MacDonald notes that (in 1906) American Graphophone records 
were manufactured using two parts; an inferior part containing lots of 
binders but little to no shellac, and a superior surface containing 
mostly shellac with few binders. Then he describes a process by which 
the old record is resurfaced with a new coating of the shellac topping, 
and after heating it again to become pliable, the newly-recoated record 
is repressed with a brand new sound groove.

This process also calls for adding more of the binder ingredients to the 
back surface of the record as well; MacDonald asserts that any excess 
material would run out of the press, leaving a record of standard thickness.

http://www.google.com/patents/US1022100

I'm presuming that by the time this patent was actually granted in 1912 
it would not have been put to use, because Columbia had converted to 
double-sided production in 1908. I would imagine that trying to 
resurface and repress both sides of a record would be awkward.

Michael Shoshani
Chicago


More information about the 78-L mailing list