French Guerry Shutters were an important part of Photography until they were put out of business by the genial Grundner shutter (for studio use) and T-P focal plane shutters (for higher speeds) after 1905.
I have a catalogue listing for the single panel Guerry, as well as the double panel system (much less common). NORKA (short for Nordisk Kamera) also produced the same design shutter.
I have a number of both Guerry and Grundner (often called eye-lid) shutters and the Grundner is definitely best for mounting inside studio cameras, like the Pickard shutter.
The design is really simple. The "barndoor" is held down by a long coiled spring in the compartment to the right of the opening. There is a thin piece of wood which is attached by cloth tape to the wooden spindle to which the barndoor is attached. When this wooden piece is depressed at the top, the spindle turns just enough to counteract the spring tension, raising the barndoor. The actuation is accomplished by an pneumatically operated rubber cylinder attached by tubing to the usual release bulb. The assembly is by no means a precise design and fixed to the fine walnut cover is a block of soft wood which has been whittled with a penknife to provide "factory" adjustment!
The usual problem with using these shutters to-day is that the natural red rubber internal cylinder will have hardened to a point where it cracks and becomes non-flexible. The same system is used with Grundner shutters with the same U/S rubber.
The Guerry I am working on has this standard rubber problem, but also has a "barndoor" which is both distorted and has numerous pin holes. I'll do the barndoor first and finish up with pneumatic action problem. This is no just a question of putting antique stock into working condition, these shutters are just about the only shutters which can manage the 10cm plus lenshoods of big Petzvals.
I wrote about the Guerry pneumatic repair back in 2011. Unfortunately all attached photos from this period were lost in a LFPF data crash.
http://www.largeformatphotography.in...rbishment-quot
I will post some pneumatic solution photos again, but the "barndoor" problem is new!
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