Abstract: A sediment control roll includes a threshold member having large apertures therethrough, a hollow sediment collection chamber, and an outflow filter having small apertures therethrough. The sediment control roll can be used to collect sediment in runoff from a construction site, or to reduce removal of sediment from an existing mass of soil, sand or other sediment. The sediment control roll can for example be made by rolling up extruded polymeric netting with filter cloth attached thereto.

Abstract: Method for transporting silicon wafers. Damage to the wafers is minimized by supporting the wafer solely by wafer supports which contact the wafer only around the periphery thereof. Preferred supports are flanged wheels which are rotatable in the plane of the wafer and are mounted on wafer supports which can be moved relative to each other between an open position and a closed position in which the wafer is supported by the supports. The flanged wheels can cooperate with the wafer and/or be driven by a motor as the wafer supports move into the closed position, to align the wafer laterally and/or rotationally.

Abstract: Circuit protection devices comprise a PTC conductive polymer element within a hollow enclosure which is sealed except for at least one vent. The vent is sealed by means of a cover member, preferably of adhesive tape. The exterior surface of the enclosure adjacent the vent and under the cover member is provided with indentations which change the internal pressure required to blow the cover member off the vent, and/or enable the cover member to open during a hot washing step and subsequently to reseal without admitting wash liquid, and/or control the direction in which gases flow after passing through the vent.

Abstract: Circuit protection devices which comprise conductive polymer PTC elements and which will provide repeated protection against sudden increases in current to high levels, e.g. 5 amps or more, in circuits which operate at, or are subject to fault conditions arising from, voltages greater than 100 volts, e.g. mains supply voltages. A particularly valuable use of the devices is in the protection of circuitry in telecommunication apparatus which normally operates at battery voltages, e.g. up to 75 volts, but which can be accidentally subject to voltages above 120 volts.

Abstract: A method and apparatus for sealing the end of a conductive polymeric strip heater, especially one for immersion use, greatly reduces the possibility of failure due to fluid ingress.

Abstract: Electrical switching apparatus comprises first and second plugs, each with a lead attached thereto, and a load socket which is connected to the second plug through a switching assembly. The first plug is connected to a wall socket controlled by a remote switch. The second plug is connected to a permanently live wall socket. The switching assembly comprises two switches, one operated by adjacent manual control means, the other being an electromagnetic relay operated, via the first plug and lead, by the remote switch. Each of the switches in the switching assembly has first and second positions. When each switch is in its first position, and when each switch is in its second position, the load socket is connected to the live wall socket. When one switch is in its first position and the other in its second position, the load socket is disconnected. In this way the load socket can be connected or disconnected by operating either the remote switch or the adjacent manual control means.