A typical folded bellows allows for axial expansion/compression, lateral offset, and angular deflection. Is there a bellows fold pattern that can accommodate a relatively large torsional rotation about the longitudinal axis?
I'm looking to prototype a waterproof (IPX67 or IPX68) flexible housing for DSLR cameras with large zoom lenses. A picture is worth a thousand words:
The photographer in the kayak is using a rain coat, which merely protects from rain. But the thought of my kayak turtling with $10k worth of camera and lens exposed makes me pucker. So I'd like to begin prototyping a flexible watertight bellows to surround the lens and mate with a flexible "bag" covering the camera body.
Of course, a regular bellows (like a bellows plunger) will allow for a zoom lens to accommodate changes in length. The problem is accommodating control of the zoom ring on the lens, which is torsional rotation of the outside of the bellows. I anticipate the maximum rotation is about 135° (+/- 65° or so from mid-zoom).
Is there a fold pattern to allow a cylindrical surface to be torsionally deformed like I'm describing?