Abstract: A gas meter includes a housing made of thermoplastic material having an inside wall defining two measuring chambers and a deformable membrane disposed between the two measuring chambers. The deformable membrane is formed from a film of thermoplastic elastomer material bonded to a synthetic fiber sheet. The periphery of the membrane is hot-welded to the wall between the two measuring chambers to form a gas-tight seal between the chambers. A mechanical drive train includes at least one lever having a hinged portion made from a thermoplastic material which is hot-welded to the middle of the membrane. The train drives a mechanical distributor disposed outside the housing.

Abstract: A pre-payment machine includes a strong-box intended for temporarily storing coins introduced into the machine prior to their collection by means of a connected collection device, this strong-box being especially designed in order to be protected against break-ins. The strong-box is made up of two sections: the first is a receptacle which forms an integral part of the housing itself of the machine and has a collection aperture usually closed by a seal; and the other is a lid secured to the receptacle by means controlled by the seal and disposed substantially within the receptacle. In one embodiment the securing means is a pin which engages the lid and the seal when in its closed position. In a second embodiment the securing means is one or more tabs formed integral with the slide which engage openings formed in a part of the lid, and one or more tabs formed integral with a part of the lid which engage openings formed in the bottom of the receptacle when the seal is in its closed position.

Abstract: In an electrical connection system between a payment card (10) including an integrated memory circuit (11), and an information transfer apparatus (15) for reading and writing data in the memory circuit, terminals (14) of the card (10) are covered with a protective layer of a plastic material (13) which is perforable and recoverable (self-healing), and the transfer apparatus is provided, for each terminal, with a projection (16) of hard metal ending at a point (17) to be urged with a defined force on to the corresponding terminal in the card through the protective layer.

Abstract: In order to compensate the hydrodynamic pressure on the turbine of a flowmeter, means are provided to create a zone of reduced pressure of constant value upstream of the turbine hub, together with means for creating a zone of pressure, on the downstream face of the hub, varying in a defined manner as a function of the axial position of the turbine. The pressure difference thus created on either side of the turbine hub produces a reaction force tending continuously to balance the hydrodynamic pressure of the fluid whatever the flow rate. The invention is particularly applicable to high flow rate water meters.

Abstract: A vortex fluid flowmeter adapted to measure the flowrate of fluid passing through a conduit by measuring the frequency of emission of alternating vortices generated by an obstacle extending across the conduit, comprises a mesh structure mounted upstream of the vortex-shedding obstacle. Said mesh structure is constituted by a grid made of bars of wires of rectangular cross-section. The distance between the grid and the obstacle is so chosen that the obstacle be in the efficient working range of the grid.