Abstract: An incremental optical encoder comprising a luminous source 1, an encoder disk 4 having windows 5 and a sensor 3 with at least two photosensitive elements. The light intensity from the source may be varied by use of a U-shaped wire 8 having a branch 12 positioned between the luminous source at the photosensitive elements.

Abstract: A variable colorant blender is provided for use as adjunct to an airbrush (A) or other spray gun. It includes a plurality of metering valves or similar devices which are actuatable wholly independently of one another for enabling the user to obtain and continuously change any colorant blend and also to perform a rapid rinsing. In preferred embodiments electric metering valve actuators are provided, which are energized by electronic circuit means contained in a control box (16) remote from that portion (10) of the blender which is affixed to the airbrush or other spray gun in replacement of the usual colorant-containing vessel 1, such control box having slides (41) for presetting and changing the proportions of colorants in the discharged blend, and possibly also a push-button (42) for controlling the amount of cleaning liquid (solvent).

Abstract: The commutator of the motor is made up of three parts assembled coaxially and insulated from one another. Each part is connected to one of the windings of the rotor. The parts are blanked from a sheet of metal, preferably silver, with a flat annular zone, an inner lug, and radial fingers which are subsequently all bent at a 90.degree. angle at the same side of the annular zone. The parts are fitted into each other in such a way that the fingers of the different parts are seated around the circumference of the commutator.

Abstract: A cylindrical, ironless, self-supporting rotor coil for use in an electrical dc-machine is disclosed. The coil is formed by at least one layer of wire, the wire having a conductive core, an insulating layer surrounding that core and an outer layer comprising a supporting material capable of being softened and subsequently solidified to make the coil self-supporting. The outer layer of the wire is at least in part electrically conductive in order to reduce the production of sparks in the commutator of the dc-machine.

Abstract: A cylindrical, ironless, self-supporting rotor coil for use in an electrical dc-machine is disclosed. The coil is formed by at least one layer of wire in which the wire is at least in part placed in an oblique direction with respect to the generatrixes of the cylindrical rotor surface. The wire comprises a central core, an insulating layer and an outer layer of a supporting material capable of being softened during or after winding and subsequently solidified. The coil is made with a final winding pitch such that the insulating layers of adjacent wire parts are at least nearly in contact, the supporting material filling the remaining spaces between the insulating layers.

Abstract: A direct current electric machine with an ironless skew wound rotor coil rotating in the air gap of a stationary magnetic circuit is disclosed, wherein the rotor coil comprises a plurality of coil sections each connected by its ends to two corresponding collector segments and each section is constituted by at least two parts. The said parts are groups of adjacent wire turns which groups are placed side by side on the rotor cylinder and are connected in parallel to the collector segments corresponding to the coil section.

Abstract: A printing device for chronocomparators comprising a striker, an ironless cylindrical coil mounted for rotation in an air gap of a magnetic circuit and connected to the striker, the magnetic circuit being formed by a permanent magnet placed inside the coil and an outer part of magnetically permeable material surrounding the coil. The coil is connected through spiral springs to a source of electric control pulses. The spiral springs provide a return force for bringing the coil back to a rest position in the absence of a control pulse. A cylinder with a helical rib is placed to be stricken by the striker and a recording strip is inserted between the striker and the said cylinder.

Abstract: A direct-current micromotor is disclosed which comprises a rotor bearing a motor winding, the rotor being arranged for rotation between a core part and a mantle part of a stator structure. The core part comprises a permanent magnet and the mantle part is made of magnetically conductive material. The motor winding is fed through a commutator comprising a collector and associated brushes. At least a part of the surfaces of the stator facing the rotor winding are provided with an electrically conductive coating to reduce the height of the voltage peaks occuring during the commutation.

Abstract: An electric actuating device for producing limited angular displacements comprising an ironless cylindrical coil mounted for rotation in an air gap of a magnetic circuit, the magnetic circuit being formed by a permanent magnet placed inside the coil and an outer part of magnetically permeable material surrounding the coil. The coil is connected through spiral springs to a source of electric control pulses. The spiral springs provide a return force for bringing the coil back to a rest position in the absence of a control pulse. Means are provided for limiting the angle of rotation of the coil.

Abstract: The rotor of an electric direct current rotating machine has at least one winding which cooperates with a stationary magnetic circuit. The winding is formed of several sections connected in series. The respective opposite ends of each section are connected to adjacent segments of a commutator associated with the winding. The sections are arranged on the rotor in such a manner that portions of different adjacent sections are disposed concurrently in the commutation zone so that currents flow through these portions in opposite directions. The invention finds application in particular to direct current motors and to motor-generators.