Abstract: Vacuum cleaner including a unit, comprising an electric motor and an associated suction fan, and a suction nozzle (36) connected to the inlet side of the unit via a dust separating device (15), either directly or via a connectable rigid conduit (13). The vacuum cleaner comprises a handheld unit (10) which when not in use is arranged to be positioned on a stationary storage unit (11), said handheld unit (10) incorporating the said unit and the dust separating device (15) and being provided with a coupling means (12) for connecting of the rigid conduit (13). For power supply purposes, by means of an extensible flex (26), the handheld unit (10) is connected to the storage unit (11) which via an additional flex (39) is connectable to a mains outlet.

Abstract: A vacuum cleaner having a suction nozzle and a dust bag (12) which is connected to the nozzle, for instance, by a tube connection, and a turbo-fan unit (27) driven by an electric motor and placed after the dust bag seen in the flow direction. The impeller (29) of the turbo-fan unit is driven at a speed above 50,000 rpm. A primary air stream created by the turbo-fan unit (27) leaves the unit via an outlet (30) to atmosphere. The vacuum cleaner also creates a secondary air stream which at least partially cools the electric motor (32) and which flows into the electric motor via one or several cooling air inlets (44) which are separated from the primary air stream. The secondary air stream can be created by a cooling fan which is separate or integral with the impeller, by a venturi-type nozzle, or by suction created by the impeller.

Abstract: An arrangement in an apparatus or a machine operated from the mains for the transfer of control commands to at least one working means (24) in the apparatus or machine, e.g. a motor or the like, via a wire (13) also used for the power supply to said working means. The arrangement comprises a control unit (10) provided for creating a control command by suppressing, in a predetermined order, at least part of one or several consecutive half-periods of a predetermined polarity of the supply voltage. Moreover, the arrangement comprises a slave unit (11) operating in response to the control command transmitted to activate the working means (24). The control unit (10) has such a design that before a control command is transmitted the control unit operates to shortly disconnect the supply voltage on the wire (13) for a period of time required for the current in the working means (24) to decline essentially to zero.

Abstract: A reluctance motor comprises a stator (11) with poles (1,1', 2,2', 3,3') which are cooperating in pairs, and a rotor (12) made from soft magnetic material and having poles (13) which are disposed diametrically opposite each other in pairs. The stator poles have magnetizing windings (14,15) which for each pair of stator poles are connectable to a DC source (18) under the control of a control device (26) in dependence on a signal from a sensor device (20) which is arranged during the movement of the rotor (12) to indicate the position of the rotor poles (13). The sensor device comprises a sensor (21) which cooperates with a disc (23) rotating with the rotor (12) and having wings (22), the number of which corresponds to the number of stator poles or to the said number multiplied by two.

Abstract: A two-pole reluctance motor comprises a stator having two diametrically opposed poles with windings, and a rotor of soft magnetic material having two correspondingly positioned poles, each rotor pole having a first portion with a peripheral extension which coincides with the corresponding extension of the respective stator pole, and an additional portion adjacent the first portion and having a pole surface situated closer to the shaft of the rotor than the first portion. A device is arranged during the starting process of the motor to drive the motor by current pulses of a magnitude which in areas of pole overlap saturates at least those portions of the stator and the rotor pole, respectively, closest to the pole surfaces.

Abstract: A reluctance motor comprises a rotor (22) of soft magnetic material with two diametrically opposed poles (23,24) of equal size. The motor further includes a stator which in a corresponding way is provided with two poles (12,13). The stator poles (12,13) have windings (14,15) which can be activated separately. Further the stator poles are so designed that the radial line of symmetry (26) of one stator pole (13) forms an angle to the radial line of symmetry (25) of the other stator pole (12). Means are provided which on start drive the two windings alternately and in continuous operation drive them simultaneously.