Abstract: A valve comprises a valve seat member and a movable valve member (preferably a disc with at least one face coated with piezo electric material) movable towards and away from the seat to close and open the valve and a sealing element made from a resilient material and attached to one of the members. The sealing element possesses an initial deformable characteristic so that initial closure of the valve causes the seating element to substantially conform to the shape of the other member and retain the so-conformed shape. The sealing element comprises first and second springs of different resiliently formable characteristics, the second spring preferably being a ring of elastomeric material, and the first spring--after initial deformation of the sealing element--being rigidly adhesively secured to the valve seat member.

Abstract: The present invention relates to controllable electric heaters, in particular heaters employing tungsten halogen lamps and suitable for use in cookers of the type having a ceramic hob below which are placed the heaters.It is an object of the present invention to provide a controllable electric heater employing two tungsten halogen lamps and other components of an inexpensive nature and which allows six different power settings to be obtained.

Abstract: A control system for a glass ceramic hob electric cooker having an array of magnetic field sensitive switches associated with each heater element. An actuator key, including a permanent magnet, has a planar base so that it can be moved over the array to actuate a selected one of the switches. The hob is completely free of all projections or holes and the actuator key is supported by its planar base resting on the hob.