Abstract: A compound shalt coupling having a flexible disk shaft, with two flexible disks or diaphragms, and a tie bolt shaft connecting two rigid or stiff shafts. One flexible disk diaphragm of the flexible disk shaft is coupled with an interference fit to the first stiff shaft, while the other flexible disk diaphragm of the flexible disk shaft is coupled with an interference fit to the tie bolt shaft which removably mounts the second stiff shaft. A quill shaft connects the two flexible disk diaphragms of the flexible disk shaft. The first stiff shaft can be a hollow sleeve with a magnet mounted therein and the second stiff shaft or power head shaft may include a compressor wheel, a bearing rotor, and a turbine wheel removably mounted on the tie bolt shaft.

Abstract: A compound shaft coupling having a flexible disk shaft, with two flexible disks or diaphragms, and a tie bolt shaft connecting two rigid or stiff shafts. One flexible disk diaphragm of the flexible disk shaft is coupled with an interference fit to the first stiff shaft, while the other flexible disk diaphragm of the flexible disk shaft is coupled with an interference fit to the tie bolt shaft which removably mounts the second stiff shaft. A quill shaft connects the two flexible disk diaphragms of the flexible disk shaft. The first stiff shaft can be a hollow sleeve with a magnet mounted therein and the second stiff shaft or power head shaft may include a compressor wheel, a bearing rotor, and a turbine wheel removably mounted on the tie bolt shaft.

Abstract: A compound shaft coupling having a flexible disk shaft, with two flexible disks or diaphragms, and a tie bolt shaft connecting two rigid or stiff shafts. One flexible disk diaphragm of the flexible disk shaft is coupled with an interference fit to the first stiff shaft, while the other flexible disk diaphragm of the flexible disk shaft is coupled with an interference fit to the tie bolt shaft which removably mounts the second stiff shaft. A quill shaft connects the two flexible disk diaphragms of the flexible disk shaft. The first stiff shaft can be a hollow sleeve with a magnet mounted therein and the second stiff shaft or power head shaft may include a compressor wheel, a bearing rotor, and a turbine wheel removably mounted on the tie bolt shaft.

Abstract: Kits which allow colors to be identified and thereby communicated by their unique chromatic and/or achromatic characteristics include a number of discrete color plaques. These color plaques are preferably arranged in chromatic and achromatic series such that individual plaques may be combined with other plaques to form a stack so that the collective color characteristics of the stack may be observed visually. In preferred embodiments, the chromatic plaques in the kits will be arranged in rows and columns in order of the individual plaque's color hue and value characteristics. The achromatic plaques, on the other hand, are simularly arranged in columns and/or rows in order of the plaque's particular achromatic value characteristic.

Abstract: Kits adapted to allow subjective evaluation and communication of gemstones include a number of simulated gemstones which are arranged in an ordered set according to their respective hue, chroma and/or value characteristics. Each of the simulated gemstones includes a multifaceted gemstone body portion (which preferably closely resembles a brilliant cut diamond) and a handle portion radially extending from the body portion. The handle portion allows the multifaceted body portion to be manipulated in ambient light conditions so the color can be adequately observed. The simulated gemstones are formed of a molded plastics material which exhibits unique color hue, chroma and value characteristics. The hue, chroma and value characteristics may be varied within an ordered set of the simulated gemstones so as to achieve a close color match with natural gemstones. These ordered sets of simulated gemstones may thus be displayed in respective trays.