摘要:
A signal to warn of the open condition of a sub-grade vault whose lid may be open or missing. A spring-loaded placard is held down in the vault by a closed lid and raises above the opening by its own stored energy when the lid is open or missing.
摘要:
A signal to warn of the open condition of a sub-grade vault whose lid may be open or missing. A spring-loaded placard is held down in the vault by a closed lid and raises above the opening by its own stored energy when the lid is open or missing.
摘要:
A portable infrared landing site illumination system is provided for fixeding and rotary wing aircraft having night vision capabilities as provided by the Army's second generation goggles (PVS-5) or the third generation goggles (ANVIS). The system employs special markers assembled from readily available disposable components and a simple above ground mounting stake. Also provided is a special laser illuminator which operates in several modes to assist all phases of the landing operation.
摘要:
A safety alert for water skiers attachable to a tow boat and automatically actuated by a regulated release of tow line tension to elevate a flag to warn other boats that a skier is "down". An elastic member is operatively connected to a reciprocal flag standard and a tow line whereupon the memory of the elastic member elevates the flag into visible position when the tension on the tow line is released from the elastic member by the release of the skier therefrom. An intermediate member circumscribes a pull rope connected to the tow line and coacts with an obstructive member or knot disposed therein to regulate the actuation of the alert and prevent false messages from being transmitted thereby.
摘要:
A maritime signaling apparatus for use on a marine vessel comprises collapsible day shapes, a rod pivotally hung from the yardarm of the vessel for displaying the day shapes which are separated a predetermined distance by spacer tubes, and means for automatically opening the day shapes as they are hoisted up the rod by a halyard line. The device is designed such that the day shapes may be supported by the halyard line and rod individually or in combination.
摘要:
A display device in which one or more prisms are moved between at least two fixed positions. Each prism has an image surface, an object surface and a reflecting surface and there is indicia placed adjacent the path defined by movement of each object surface. The indicia is visible at an image surface in only one position of the prism.