The invention describes a cutter which is for positioning in an underground pipe which is too small for man entry. The cutter is for cutting holes in previously applied pipe lining which cover lateral connections. The cutting must be controlled from above ground. Flexibility and positionability is achieved by mounting the cutter head at the free end of a boom body, the other end of which is mounted through a universal joint to a mounting so that the boom can swing in any direction. The cutter is...

An electronic cross connect frame for an exchange or a multiplexor therefor is provided in which an analogue access matrix is provided for providing a limited number of spare cards or different cards to which any of the lines may be switched to provide a "sparing" or alternative services.

A manually operated resuscitator is provided. The resuscitator has an inner member provided in an outer member. The inner and outer members have an arrangement of apertures and valves to enable ambient air to be drawn into the pump in its non-pressurizing stroke and on a pressurizing stroke the inner member is capable of discharging air. The pump is connected to a mask by a rigid conduit. The face mask is positionable over the nose and mouth of a patient so as to form a fairly airtight seal with...

A container for fluids which is closed by a cap which is inserted into the neck of the container. A coupling member is interposed between the neck and the cap which is fitted to the container after it has been formed. The coupling member is readily attachable to the container from its exterior without requiring any modification to the container and has a central bore to receive the cap.

A nail of "I" section having a flat web the flanges along the opposite sides of the web of the section extending in the lengthwise direction of the nail, the web having a gap of V form extending inwardly of the web from the leading end of the nail the edges of the gap diverging from the inner end thereof so as to provide a pointed end at each side of the web at said leading end of the nail. The edges of the gap can each be formed as a knife edge to facilitate penetration of the nail.

A gap between tunnel segments 1 is sealed by rubber sealing members 8 that are provided with grooves 10 and tubular cavities 11. To improve sealing when a high pressure is applied to one side of the seal, at least one cavity nearest that side is open to the high pressure through apertures 12.

A container having cushioning means for protecting the contents of the container against shock damage, the cushioning means comprising one or a plurality of enclosed volumes or cells housing a fluid which may be a gas such as air and defined by an at least partly resilient envelope which forms part of the structure of the container.

A wok having an electric heating element a first portion of which extends in the area of the underside of the central portion of the wok and a second portion continuous with the first portion which extends circumferentially on the underside of the wok in a substantially part circular path extending over curved portions of the wok surrounding the central portion, the heating element being secured to the outer surface of the wok.

An inverter charger, fed with d.c. from a battery, to supply a.c. to a load, comprising eight inverters stages which each provide an alternating step function output current and which are arranged in two sets of four, the inverter stages of each set being serially connected and driven sequentially to produce in combination, a generally sinusoidal step function waveform comprising fifteen degree steps, the two step function waveforms thus produced, one by each set, being serially combined, and mu...

Zipper is the time-synchronized frequency-division duplex implementation of discrete multi-tome (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. When all transmitters are time synchronized, the near end cross-talk (NEXT) and near end echoes injected into the received signal are orthogonal to the desired signal. The present invention provides a telecommunications transmission system using zipper and having at least two VDSL systems. Each V...