Abstract: A pedal latching mechanism for a machine to mix mortar and plaster, which includes a latch activated by a pedal lever, the latch mechanism including a rod biased against the vertical surface of the drum of the mixer and engages with a protuberance formed by a piece of metal welded to the vertical surface of the drum and bent in such a way as to form an inclined plane.During the rotation movement of the drum for the unloading of the mortar, the latch which is locked by the pedal, remains in contact with the surface of the inclined plane at first and then with the vertical surface of the piece of metal. When the drum returns to the upright position, the latch resumes automatically its latching position against the protuberance since it is biased by a spring.

Abstract: A contact-type keyboard comprises a plurality of modular keys and a support panel (11) provided with openings (12) in which the keys are inserted. Each key is provided with a pair of resilient tongue portions (51, 52) which lock it to the panel (11) and which are deformable to permit the key to be easily removed from the panel (11). Each key further comprises a resilient system formed by a dome-shaped spring and a coil spring, which are interposed between a movable actuator and the subjacent conducting parts of an electrical circuit.

Abstract: The printer comprises a solid or liquid ink jet head 100 arranged to print one dot at a time on paper running over a platen 80. The head is carried by a carriage 48 movable transversely with simple harmonic reciprocating motion. In order to reduce the effect of inertial forces when the carriage reverses its movement, the drive is effected by an eccentric peg 70 on a disc 276, the peg engaging in a guide slot 54 of the carriage perpendicular to the direction of reciprocation. An eccentric cam track 71 in the disc engages a peg 92 on a counterweight 90 for counterbalancing the inertial forces of the carriage. In order to synchronize the printing operation with the carriage movement, an optical strobe disc 258 is rigid with the disc 276 and has slots 258 disposed at a pitch varying according to the harmonic motion. The platen 80 is rotated intermittently by a helical cam 277 carried by the disc 276 and a peg wheel 280, 281.

Abstract: The printer comprises a solid or liquid ink jet head 100 arranged to print open dot at a time on paper running over a platen 80. The head is carried by a carriage 48 movable transversely with simple harmonic reciprocating motion. In order to reduce the effect of inertial forces when the carriage reverses its movement, the drive is effected by an eccentric peg 70 on a disc 276, the peg engaging in a guide slot 54 of the carriage perpendicular to the direction of reciprocation. An eccentric cam track 71 in the disc engages a peg 92 on a counter-weight 90 for counterbalancing the inertial forces of the carriage. In order to synchronize the printing operation with the carriage movement, an optical strobe disc 258 is rigid with the disc 276 and has slots 258 disposed at a pitch varying according to the harmonic motion. The platen 80 is rotated intermittently by a helical cam 277 carried by the disc 276 and a peg wheel 280, 281 .

Abstract: In a generator of strobe signals an electret is interposed between a fixed and a movable armature moving with a translatory or rotary movement. The strobe signals are generated by the electrostatic induction of the electric charges trapped in the electret according to a selective flux pattern.