Linhof Dekel Shutter History

[Rick in CO]

This statement in the Focal Encyclopedia of Photography is not correct.

First, as discussed above, Christian Bruns was awarded patents for both the Compound (1902) and the Compur (1910) shutters, not Friedrich Deckel. Deckel commercialized both shutters with the assistance of Carl Zeiss.

Second, there is no evidence that Linhof was ever in business with Friedrich Deckel, they were in fact competitors.
Linhof's shutter patents (1892 and 1896) had expired by 1911, and, compared to both the Compound and Compur, were by that time, obsolete.

Finally, it was Bausch & Lomb who on May 15, 1888 patented perhaps the first inter-lens shutter, USP 382,858.

Linhof's between the lens shutter was submitted and patented on 8 November, 1892, DRP 72064.

[David Lindquist]

In designing the Compur shutter, Deckel apparently took the Compound shutter and replaced the pneumatic cylinder with Klein and Brueck’s clockwork slow speed escapement, thus simplifying and expediting the new design. The name “Compur” reflects this genesis from the Compound shutter, being a fusion of “Compound” and “Uhrwerk”, the German word for “clockwork” (see Reiss). Consequently, the Compur is actually a “Clockwork Compound” shutter."

Not sure why I didn't comment on this when it was first posted. Rudolph Klein and Theodor Brueck were founders of Ilex Optical Co. with financial help from Morris Rosenbloom, the company's first president. From Kinglake's The Photographic Companies of Rochester, New York , Klein and Brueck were inventors of the slow speed escapement of which Friedrich Deckel was "...Probably the largest licensee..."
There are three U.S, patent numbers for this mechanism, 1092110, 1091666 and 1122950. I have examples of dial-set Compurs and have seen additional examples of both dial-set and rim-set Compurs that are marked with these three patent numbers.

David

[Rick in CO]

Christian Bruns applied for his Compur shutter patent "Objektivverschluss mit Raderwerk" in Germany on 6 June, 1910.
Klein & Bruek applied for their ILEX shutter patent in the USA on 25 June, 1910.

Both inventions were for a gear train-activated slow speed escarpment and independently arrived at.

Bruns applied for a USA patent on 9 November, 1911, and was approved on 18 February, 1913, 1,053,152.

The Bruns patent was approved in Germany on 26 March 1913, DRP 258646.
The ILEX patent was approved in the USA on 31 March, 1914, 1,092,110.

Both patents were recognized, however, the end of World War 1 resulted in the forfeiture of German patents.
Thereafter, only the ILEX patent was recognized, hence the acknowledgement of such by Friedrich Deckel.

Friedrich Deckel trademarked the "Compur" name on 24 January, 1912, Nr. 152947.
Various sources state that Zeiss bought the Compur shutter from Bruns, which Deckel manufactured and marketed.
Christian Bruns died sometime in 1912 (not found the exact date) before the Compur patent was awarded.
His son? Heinrich continued the company, but not much else appears to have happened except for the extension of previously awarded Gebrauchmusters ("Utility Models", awarded for 3 years and extendable for an additional 3).

It is interesting that an Exhibition of the previous 100 years of Munich Photographic History in 1939 Photographische Korrespondence described Steinheil's (Carl August & Adolph), Alois Lörcherer, Philip von Seidel, Christian Bruns and Valentin Linhof's contributions.
No mention of Deckel.

[David Lindquist]

Christian Bruns applied for his Compur shutter patent "Objektivverschluss mit Raderwerk" in Germany on 6 June, 1910.
Klein & Bruek applied for their ILEX shutter patent in the USA on 25 June, 1910.

Both inventions were for a gear train-activated slow speed escarpment and independently arrived at.

Bruns applied for a USA patent on 9 November, 1911, and was approved on 18 February, 1913, 1,053,152.

The Bruns patent was approved in Germany on 26 March 1913, DRP 258646.
The ILEX patent was approved in the USA on 31 March, 1914, 1,092,110.

Both patents were recognized, however, the end of World War 1 resulted in the forfeiture of German patents.
Thereafter, only the ILEX patent was recognized, hence the acknowledgement of such by Friedrich Deckel.

Friedrich Deckel trademarked the "Compur" name on 24 January, 1912, Nr. 152947.
Various sources state that Zeiss bought the Compur shutter from Bruns, which Deckel manufactured and marketed.
Christian Bruns died sometime in 1912 (not found the exact date) before the Compur patent was awarded.
His son? Heinrich continued the company, but not much else appears to have happened except for the extension of previously awarded Gebrauchmusters ("Utility Models", awarded for 3 years and extendable for an additional 3).

It is interesting that an Exhibition of the previous 100 years of Munich Photographic History in 1939 Photographische Korrespondence described Steinheil's (Carl August & Adolph), Alois Lörcherer, Philip von Seidel, Christian Bruns and Valentin Linhof's contributions.
No mention of Deckel.

Thank you very much for this. I've wondered if independent invention was part of the story.

David

[BrianShaw]

Thank you very much for this. I've wondered if independent invention was part of the story.

David

Very well could have been; simultaneous invention happened in several earth-shattering technological breakthroughs and although one person/company often won the glory, others never got the credit they were due. Same with licensing agreements and other types of "alliances and collaboration" between inventors/entrepeneurs, some of which may come and gone at various parts of the process. Successful commercialization often determined who got the credit.

As Rick has done here, it's just as important to observe the patent application date as it is the patent issuance date as they sometimes are quite far apart.

I'm still trudging through the details of this recent discussion and finding it very, very fascinating!

[BrianShaw]

Another place to look for clues on inventions, which I do for other types of 19th Century technologies but have for photographic technologies, are the technology/invention publications of that day, such as Scientific American, The Engineer, English Mechanic and World of Science. These types of publications focused on promoting invention, announced patent issuance with empahsis on their national locality but also international, and often published articles on new technlogies/inventions which seems to have put the one individual ahead of other (sometimes simultaneous or competing) inventors in terms of credit and awareness.

[Tin Can]

Many many machines were designed and Patented

1890 on

However a lot was impossible to actually make as metallurgy lagged

example automotive engine design

I have a couple tomes from 1920 that fascinate me

Particularly Dynamometers

I operated and repaired a huge Studebaker Dyno made during WW 11

many vacuum tubes and a lot of cold water

in 1978

[BrianShaw]

...
There are three U.S, patent numbers for this mechanism, 1092110, 109166 and 1122950.
...

Hi David. Thanks for this great information. There is a minor typo, however, in the bolded patent number. It should be US1091666.

[David Lindquist]

Hi David. Thanks for this great information. There is a minor typo, however, in the bolded patent number. It should be US1091666.

Thank you so much. Just corrected it. No matter how hard I look at a series of numbers like that I do't always spot my error(s). Of course now it's obvious being one digit too short.

David