Abstract: An air pressurization and control system for a low air loss air floatation mattress or cushion is disclosed. The control system controls air supplied to the air floatation mattress within a range of pressures and flowrates so as to inflate all of the cells of the mattress and to maintain a flow of air to all of the cells over an extended period of time while maintaining all of the cells at a desired level of inflation for the air floatation support of the patient without any of the cells exerting decubitus pressures above the maximum desired decubitus pressure and so as to prevent collapse of any of the cells. A sensor is provided for sensing the pressure of the air within the common supply.

Abstract: An electrically powered window shade with selectively variable shading characteristics is installable within a window opening for selectively blocking (by absorption or reflection), filtering and/or transmitting light through the window shade into a room for purposes of energy control and/or decoration, etc. This window shade comprises an upper roller assembly, a lower roller assembly, and an elongate flexible web wound on the upper and lower roller assemblies, with the web being longer than the spacing between the upper and lower roller assemblies. Each of the roller assemblies comprises an elongate tubular roller, bearings engageable with the end of the roller for rotatably journaling the ends of the roller with respect to the window. The web is scrolled onto and from the rollers as the latter are rotated about their respective longitudinal axes.

Abstract: Safety control apparatus of substantially improved reliability and sensitivity is provided for detecting faults and automatically deenergizing electrically powered mobile or portable equipment, such as mining machinery, which is energized in the field by means of relatively long cables often carrying high voltage electrical power from a sub-station, in the event of either a short circuit between a sensing conductor and ground or any failure of the ground connection included in the system to protect the operators of the equipment and the equipment itself. The improved safety apparatus is further characterized by its ability to respond to detected faults so quickly as to virtually eliminate any chance for operator injury or damage to equipment, even when very high voltage power is being used.