Abstract: The invention is a rotary joint for singlemode optical fibers, having a fixed and a rotating part to permit the transmission of optical signals across a rotational interface (such as a winch or turret) with minimal insertion loss and, in particular, low reflections (good return loss). There is no need of conversion to electrical signals; the device is passive. It may be use an oil of refractive index matched to that of the glass fibers and to that of fiber tapers or lenses used to expand the beam emitted from one fiber and contract it for transmission into the other fiber. The device is bidirectional. By use foil, through precision techniques for building and mounting the optical and mechanical components, and by use of advanced bearings, both the insertion loss and unwanted reflections (return loss) can be minimized, thereby making it suitable for use with singlemode fiber.

Abstract: An adapter for detachably interconnecting an exhaust stack with an exhaust actuated device comprises a hollow, frustoconically shaped body having first and second ends, and an inclined sidewall extending therebetween. The body first end is open for receiving exhaust gases from the stack therethrough, and the body second end communicates with the first end and is operably connected with the exhaust actuated device. The sidewall of the body includes advancing spiral threads on the exterior surface thereof which are shaped for engaging an interior, free edge of the stack, rotatably locking the adapter therein, thermally expanding and forming a secure and substantially airtight seal therebetween.