[LargeFormat] Compound Shutters

[Richard Knoppow]

----- Original Message ----- 
From: "Wilkes, Don MSER:EX" <Don.Wilkes@gems9.gov.bc.ca>
To: <largeformat@f32.net>
Sent: Thursday, December 04, 2003 2:22 PM
Subject: RE: [LargeFormat] Compound Shutters


>
> >   Again, I don't have a starting date for D.R.P. but it
was
> > used until sometime after 1945. D.B.P. was adopted at
the
> > end of the war but was not immediately used so one finds
> > equipment made as late as 1950 or so still marked DRP or
>
> Oh, it means German Republic *Patent*, then!  That would
explain why I
> couldn't find a reference to it either online or in one of
the office
> Almanacs... I should have realized this, as last July, I
had a short note
> from Mr. Arne Croell on my old Carl Zeiss Jena 165 f/6.3
Tessar, which I was
> trying to date.  It has an apparent serial number of
166752, and is marked
> DRP 142293.  He said that he was travelling, and didn't
have his list of
> Zeiss numbers at hand.  However, he mentioned that list
only starts in 1927,
> at which point the serial #s were already past the million
mark.
>
> So, it looks like DRP is pre-30s, at any rate.
>
> By the way, Mr. Croell had an article on VEB Carl Zeiss &
Docter Optic
> lenses in the July/Aug 2003 issue of View Camera, which is
what prompted me
> to write to him. If Mr. Croell is listening -- could you
possibly tell me a
> bit more about my lens, especially its likely date of
manufacture?  I've
> never found it mentioned in any references.
>
> Cheers!
> \donw
>
  The earliest Zeiss serial number in McKeon's guide is
173418 from 1912.
  DRP 142294 is the original Paul Rudolph patent on the
Tessar, the equivalent of USP 721,240
  This is one digit earlier, are you sure this is correct?
  The German Patent Office was established in 1878. DRP and
DRGM probably date from that time. They were in use until
the end of the Deutches Reich in 1945 and the establishment
of the Bund. The abbreviations DBP and DBGM were used after
that although equipment made up to the early 1950's
sometimes has the old abbreviations.
  I found a site which allows searching German and other
patents and has old patents on it, at least in the form of
abstracts. This is http://www.depatisnet.de
  A search for the patent above got a non optical patent for
something. I don't have enough German to make out the claims
and the drawing makes no sense whatever.  The Rudolph number
comes up with the Tessar patent. I don't think one can
search for design patents on this site. There is another
site which might allow such searches but its all in German.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com