An alarm system to keep an aircraft pilot or a vehicle operator alert utilizes a first timer to activate visual alarm. The first timer is reset by actuation of the aircraft communications press-to-talk button. If the pilot fails to reset the first timer within a predetermined time, a second timer triggers an audio alarm. Once the audio alarm is triggered, it remains triggered and not resettable for a predetermined period of time. During normal operation of an aircraft during landings and takeoff...

A communications network comprises a plurality of stations which can communicate via a ring. Information is transmitted from one station to another in message blocks which circulate around the ring. The message blocks include control bits and a protocol is employed which ensures that no one station can monopolize the available message blocks. Also described is a technique which allows each station independently to assess the current spare capacity of the network. A link multiplexer may be used i...

A continuously variable transmission unit includes a disc drivingly connected to a first shaft, the disc having a frusto-conical groove in its outer periphery, the walls of the groove being inclined inwardly towards one another; an annular element is mounted for rotation about the disc, so that the inner periphery of the annular element is located within the groove, opposite faces of the annular element engaging the opposed walls of the groove. A connection is provided for transmitting rotation ...

A sonar system for a water craft including a transducer assembly mounted to the hull of the water craft, and a control circuit for applying signals to the transducer for forward transmission by the transducer and for sensing signals reflected from objects forwardly of the craft and for causing actuation of an alarm. The transducer assembly is mounted for pivotal movement relative to the hull such that during pitching motion of the craft, the signals transmitted by the transducer remain in a hori...

A building system which utilizes flooring supported by adjustable posts and individual beams extending between the posts which may be temporarily supported in excavations to enable the floor to be erected, and then adjusted for level. The excavations are subsequently filled with concrete to form footings. The posts may extend upwardly beyond the floor beams to form wall supports.

A one-piece metal mounting device for an adjustable or eccentric bearing of a precision slide system has a spigot forming a journal for the bearing and lateral extensions one of which has an elongate through bore for receiving a hexagon headed adjusting bush and the other has a cylindrical through bore for receiving a screw. The bush also receives a screw, both of which pass into blind threaded holes of a machine bed of the slide system. The device is mounted on the bed and adjusted in a plane p...

The minehunting system includes a remotely operated vehicle which is driven ahead of a vessel. The vehicle is equipped with a sonar system for detecting, classifying and disposing of a mine. The sonar system comprises an acoustic mirror sonar which includes a dual field-of-view reflector, a height finding element and a dual frequency classifier. The vehicle has a autopilot which, is conjunction with control algorithms in a shipborne tactical computer on the vessel provides navigation and manoeuv...

The present invention relates to batteries and battery systems. In particular, a battery is described which comprises a container which houses a plurality of cells. Each of the cells share a common negative terminal. Two or more positive terminal cells are provided. The specification also describes the use of such batteries to power the cranking and auxiliary circuits according to a cell discharge management scheme. Methods of forming such batteries are disclosed in which alternate positive and ...

A set of components for use in constructing a sliding sash window comprises an outer frame member having parallel longitudinally extending channels or recesses therein adapted to accommodate balance spring mechanisms, cover members engageable with the outer frame in order to enclose or partially enclose the channels or recesses at appropriate regions of the assembled frame and to hide the balance spring mechanisms from view, and glazing members engageable with retaiing means formed on the cover ...

An aircraft navigation system has a digital map store of terrain features or man-made features in the region over which the aircraft is flying. Infra-red television cameras view the surrounding of the aircraft. Their outputs are supplied to processors in which the camera outputs are compared with a library of features transformed according to the camera viewing angle. Information about those features identified is supplied to a correlator which correlates the features against the map store to id...