A punching device for automatic punching machines for the punching of paper, cardboard and the like, comprising: a driving mechanism for a top shoe; such as a rocking lever drive, elliptical cam drive, or wedge-form transmission; a stationary bottom shoe supporting a counter-punch; a movable top shoe supporting punch knives; and a gripper bar arrangement for intermittent forwarding through the punching device of sheets to be punched wherein the drive mechanism for the top shoe is located between...

A Gunn effect oscillator comprises a body of semiconductor material in which electrons are injected from one region to another region via a very thin intervening system. The thin region has a thickness which is less than the mean free electron path length and is typically of the order of 100 .ANG., which results in hot electrons being transferred from the injection region into the other region in which electron bunches form.

A connecting device is included in oral and extra-oral prostheses of the type which is partially implanted in bodily tissue, primarily bone tissue, by means of a specifically designed anchorage unit (a fixture). The connecting device provides more favorable stress and force distribution between the implanted and the outer portion of the prosthesis located peritissually. The connecting device includes an outer, cylindrical sleeve-shaped patrix (6) for connection to the outer prosthesis portion, f...

Hand-held electrical apparatus having an electrical detector in the form of a conductive sensor adjacent to any exposed electrical part so that if the apparatus becomes wet or damp the water will form path of conduction between the exposed electrical part and the sensor. A conductive path from the sensor forming part of the supply lead to the plug, and the plug comprising normally closed mechanical switch at least in the live line from the mains supply to the supply lead to the apparatus and a c...

A semiconductor device comprises a drain region, base regions, gate electrodes formed over the drain region between two adjacent base regions through an insulating layer such that each bridges the surface of the drain region to partially cover the two adjacent base regions, source regions provided in the base regions, a source electrode provided on the source regions, and a metal gate electrode wiring contacting the gate electrodes. The metal gate electrode wiring includes closed loop portions a...

A scanning device, particularly for viewing above the core of a nuclear reactor, has links 29 pivoted together at 33 with means 35, 35a limiting relative movement in one sense. At least one link carries a transducer 36, preferably ultrasonic, for viewing. There may be two transducers arranged to view in different directions. The transducers may be mounted in a removable module. A deployment arrangement may have a vertical hollow mast 20 down which the links can be pushed to engage a deflect elem...

Improvements to electrical devices comprising conductive polymer compositions are described. The device, preferably a heater, comprises two electrodes, preferably planar electrodes and a conductive polymer composition, which preferably exhibits PTC behavior, and which is preferably sandwiched between the electrodes. At least one of the electrodes comprises a metal with a thin layer of high resistivity material attached thereto, e.g. anodized aluminum, so that the layer separates the electrode an...

A fluidic device, in particular a vortex diode, has a vortex chamber formed by spaced apart end walls and a peripheral side wall. An axial port is provided in one end wall and a further port permitting tangential flow into or out of the chamber is provided in the other end wall.

An accessory for an injection device of the kind in which liquid is drawn or expelled along a hollow needle comprises a protective sleeve for surrounding the needle. The sleeve has at least an end portion which is reciprocable in the direction of the length of the needle between an extended position in which the point of the needle is located within the sleeve to shield the point of the needle and a contracted position in which the point of thr needle projects from the sleeve, to enable an injec...

The invention relates to the idea of a device which can be interposed between a lamp and its socket for a variety of purposes including control of the operation of the lamp, hazard and security status detection. In one form the device is responsive to the light's wall switch being turned off and then rapidly on again to initiate a periodic energization of the lamp so as to give the impression that the room in which the lamp is located is occupied. Various other uses for the device are also discl...