Abstract: A barrier assembly for a Langmuir trough is arranged for a substrate to be carried automatically to-and-fro on a dipping head over a fixed barrier into monomolecular layers A, B on a common subphase so as to stack layers ABABAB . . . on the substrate. The layers A, B are confined by the barrier and two constant perimeter areas formed by a single flexible band passing over rollers. By adjusting the positions of bridges that carry some of the rollers, the confined areas can be contracted to compress the layers A, B. In an alternative mode the substrate receives a layer from layer A while a new layer B is being formed, the substrate then being transferred to layer B while a new layer A is being formed. This involves an oscillating rather than a rotating movement of the substrate.

Abstract: A multi-bladed propeller and shaft assembly is provided in which air can be fed to the propeller blades to reduce the effects of cavitation. A shaft leads to a multi-bladed propeller and carries a sleeve formed with inlet passages and axial and radial passages leading to the respective blades. A slip ring supported in an anti-rotation device allows the shaft sleeve to rotate within axially spaced bearings of the slip ring. Axially spaced air seals together define with the body of the slip ring an annulus within which inlet passages rotate. Each seal is formed as a multiplicity of arcuate segments resiliently biased towards the sleeve and having movably sealed end face portions to maintain pressure tightness. The body further has a radial flow passage for admission of air under pressure to the annular space and a flexible fluid connector connects the radial flow passage to an air supply line leading from the hull structure.

Abstract: A barrier for confining an area of monomolecular film on a Langmuir trough comprises a first barrier portion consisting of a transverse part and a longitudinal part and a second barrier portion connected at its ends to the ends of the first barrier portion and having two further longitudinal parts, one close to the first longitudinal part and the other further away. By altering the position of another transverse part joining the two further longitudinal parts the area enclosed is varied by changing the length of the longitudinal part close to the first longitudinal part and altering the length of the longitudinal part further away by an amount such that the sum of the two altered lengths remains constant.

Abstract: A thermal sleeve for a gun barrel is in the form of a cylinder of a substantially rigid thermally insulating material with a series of longitudinally and circumferentially spaced spacer members disposed on the inner face of the cylinder. The spacer members engage with the gun barrel and define an annular gap between the cylinder and the barrel. The sleeve further includes means for sealing the annular gap as well as means for securing the cylinder on the barrel to ensure pressurized contact of the spacer members with the barrel.

Abstract: The invention concerns a hull and a submerged propeller unit demountably fitted to the hull and continuously rotatable through 360.degree. of azimuth relative to the hull to give full thrust in any required direction. An aperture in the hull is surrounded by a fixing flange to which extend a drive input shaft for the propeller unit and at least one steering drive shaft. At least one steering drive motor is mounted in the vessel and is connected to the steering drive shaft to effect rotation thereof. A gearbox casing of the propeller unit fits in the aperture with a circumferential flange releasably bolted to the fixing flange. A stem depends from said casing and is rotatably supported therein at its upper end to act as a steering tube for a propeller rotatably supported at its lower end. A steering gear wheel in said casing through which the stem passes and to which it is secured effects rotation thereof.

Abstract: An office partition is formed by interconnection at adjacent posts of screens each comprising a load-carrying frame of posts and rails. Cladding panels are demountably supported on each face of the frame at an outward clearance from the posts and rails. Each cladding panel has on its concealed face a pair of horizontally spaced frame members formed with lower and upper slots to engage respectively with (a) out-turned tongues of hinge clips on the lower of said pair of rails, and (b) by means of spring latch in the upper of said slots with catches under the upper of said pair of rails. At least one cable carrier in the screen extends along and is supported by a rail, so that electrical wiring laid in the cable carrier of one screen can pass out of the screen in the gap between a panel and a post or rail and can pass in the gap between the panels and the posts across the posts to the cable carrier of the adjoining screen.

Abstract: In a marine anchor for coupling a tether to an anchoring chamber the tether terminates at a connector having a flange that abuts a flange of an anchoring chamber. A collet connector is expandible to trap flanges, in an external groove thereof, thereby establishing a primary load path. The mouth of the anchoring chamber is further provided with an out-turned flange engaged by locking fingers and operable by actuator means to establish a secondary load path from the anchoring chamber to the tether while the anchor is being established or released. The coupling can be separated without damage under high loads or when the tether is at an angle to the chamber.

Abstract: A dynamometer comprises a drum mounted for rotation and driven by a drive motor, a test body coupled to the drum for rotation therewith in a fixed velocity relationship, a sensor apparatus for deriving the energy absorbed or dissipated by the test body, a sensor for determining the rotational velocity of the drum or body, and a control apparatus responsive to the energy absorbed or dissipated and to the rotational velocity and operative to supply a control signal to the drive motor to maintain the energy absorbed or dissipated as a predetermined function of drum speed.

Abstract: A thrust bearing assembly includes a carrier member having formed therein an annular slot, a plurality of bearing members, which may be thrust pads or guide members, being received within the slot. Each bearing member has a radially outer surface and an opposed radially inner surface, two spaced regions of the radially outer surface making bearing contact with the associated radially outer sidewall of the annular slot, and a region of the radially inner surface of the bearing member making bearing contact with the associated radially inner sidewall of the annular slot. The bearing contacts prevent, for each bearing member in the carrier member, both radial movement and rotational movement about an axis through the bearing member, and are such that the bearing members are capable of being fitted into slots within a wide range of curvatures.

Abstract: Propulsion unit for a marine vessel intended for operation under severe ice conditions comprises a multi-bladed propeller, which may be of fixed or controllable pitch, a stationary duct, which may take the form of a nozzle, within which the propeller runs and is protected peripherally against ice damage, and, at the forward and aft ends of the duct, water-guide members in the form of vanes and/or blades which are more massive than is required by their water-guiding functions and which restrict the size of ice masses that can encounter the propeller by entering the duct at its opposing ends. The duct may embrace the propeller peripherally around the full 360.degree.. The water-guide members may be secured at their outer ends to the duct and at their inner ends to ring members co-axial with the propeller. The upper quadrant of the duct may be secured to the hull of the vessel and the lowest portion of the duct to a skeg extending beneath the duct.

Abstract: A marine tether anchoring device comprises an anchor body and a segmented spring collet that moves axially relative to the anchor body. As the anchor body moves downwardly relative to the collet the upper end of the collet is expanded by a wedge structure which is attached to the anchor body and lockingly engages the wall of an anchoring chamber. The lower end of the tether line is attached to the wedge structure and cannot escape from the anchoring chamber. Release is effected by slackening the tension on the tether line and supplying fluid to a piston supported in the anchor body so that the piston forces the collet downwardly and releases the segments of the spring collet from the face of the wedge structure. Retraction of the collet is completed by a cam ring that engages faces on the collet as final downward travel of the collet takes place.

Abstract: A releasable marine tether connection comprises a tether having a segmented spring collet which can be expanded to become trapped in an anchor chamber. A spigot is provided in the base of the chamber which urges the plug upwards relative to the collet when the tether is pushed into the chamber to make the connection. To release the connection tension is removed from the tether and the plug moved down to allow the spring collet to close and move out of the chamber.