Extensive studies of real-life masseurs at work convinced designers at Human Touch Technology, Long Beach, Calif., that any massage chair with more than four massage touch points gives less powerful and effective massages. So the firm's new chair, the HTT-800, uses only two massage discs supported by high precision, heavy-duty, sealed ball bearings. The discs are driven by a single, high-power dc motor which can rotate at various speeds in either direction. The two uniquely shaped disks rotate in a three-dimensional elliptical orbit to gives the chair its humanlike massage feel.

The support structure of the HTT-800 uses rigid unibody construction and is formed, punched, and pressed from T5052 aluminum alloy. The chair can withstand more than 700 lb of pressure. A wedge-roller transport system guides the massage discs in a V-groove that eliminates the need for side-to-side guidance. Two spring-loaded center wheels on the massage head exert opposing pressures, keeping the head firmly in place at all times. There's no lubrication to attract dust and no rattling noises that are common in conventional flat wheel/U-frame designs. To prevent vibrations, many moving components are encased in sound-dampening rubber bushings and covers.

Transport and guide rollers, as well as massage rollers, are constructed of nylon over-molded with a soft thick polyurethane cover for strength. Guide and tracking components are nylon, or Delrin, which resists wear.