Abstract: A support for the rotor shaft of a centrifugal pump with permanent-magnet electric motor. The motor is of the type which comprises a laminate-pack stator with a coil-like winding and a rotor placed in a cylindrical chamber which is separate from the stator, the rotor being rotatable about the shaft which is fixed axially therein. The support is characterized in that it comprises a tubular shank which extends from the bottom of the chamber and in which one end of the shaft is force-fitted. The bottom has a through hole at the shank.

Abstract: Permanent-magnet rotor for electric motors including at least two semitubular permanent magnets which are at least partially embedded in a core made of two-component epoxy resin or plastics. The core is obtained in a mold by molding in place or pouring over a pre-molded casing that contains the magnets, or by pouring so as to form, together with said core, a containment casing.

Abstract: An electronic immersion heater includes a tube closed at one end that contains in succession from its bottom to its open end: a heating element, an electronic circuit board with the corresponding support and with a temperature sensor, and a hermetic plug. The electronic heater is characterized in that the sensor is pushed into direct or indirect contact with the tube by means of a single helical spring, which furthermore simultaneously acts as a spacer and as an electrical contact, without conventional rheophores, between the temperature sensor and the electronic circuit board.

Abstract: Device for starting a synchronous motor with a permanent-magnet rotor, particularly with two stator poles and two rotor poles, including a static power switch, a triac, arranged in series between the stator winding of the motor and the alternating-voltage source at mains frequency. The triac is controlled by an electronic circuit which processes three factors, namely the current flowing through the coil of the synchronous motor, the position and polarity of the permanent magnet of the rotor, and the polarity of the alternating-voltage source.

Abstract: Aquarium filter having a box-like body defining a first mechanical filtration region provided with mechanical-action filtration means and a second biological filtration region having a chamber provided with biological-action filtration masses which are crossed in a downward direction by fluid at low speed. The second region is provided, in a downward position, with a collection channel system which is connected to the intake duct of a recirculation pump and with a bypass opening which deflects part of the water arriving from the first region directly into the channel system.

Abstract: The improved filter particularly for aquariums comprises one or more perforated plates which are arrangeable side by side on an aquarium bottom and which are provided with protrusions which keep them raised so as to form an interspace. The plates are coverable by gravel or other material, and at least one of them is connected to a tube for drawing water from the interspace. Each of the plates is provided with elements suitable for channeling the drawn water toward at least one passage which is provided with a cock suitable for adjusting its flow.

Abstract: The pump comprises a cylindrical container for an internal element, associated with a known permanent-magnet and defining two chambers, a lower suction chamber and an upper chamber for the impeller. The chambers have respectively a suction inlet and a discharge outlet. The internal element, actuated by a lever, is coupled to the container so as to be rotatable between two positions in which the suction inlet uncovers thereon respectively an axial port and a radial port while the discharge outlet uncovers respectively a radial port and the axial port. An element for throttling the axial port in its operation as suction inlet is rotatably coupled to the container below the suction chamber and is actuated by a second lever.

Abstract: The piston type metering pump includes a synchronous electric motor, for example of the permanent-magnet type, which transmits its rotary motion to a speed reducer which is in turn associated, by means of a connecting rod-crank kinematic system, to a piston which is slidable in a hollow body in which it defines a variable-volume chamber. The chamber has, at its top, openings on which fluid intake and discharge valve means act.