Abstract: A cash register with a keyboard (31), journal printer (47) and a check slip printer (32) is controlled by a microprocessor system with a CPU (102), a program ROM (105) and a RAM (106) including various registers for storing running totals of various types. The printer (32) prints till receipts and end-of-day check slips authenticating non-rigged operation of the cash register. Thus, each time such a check slip is printed a fresh bit of an EPROM memory (106) is set from 1 to 0 under control of a register (181) and a pulser circuit (191), the EPROM being fixed non-removably to the machine and shielded aginst UV erasure. The printed check slip includes the serial number thereof as represented by the EPROM contents, a special symbol identifying a non-manipulatable machine and the machine number recorded in a section (161) of the EPROM. In a modified embodiment the EPROM is replaced by a counter, e.g. a mechanical counter, which can only be incremented (and cannot be decremented or zeroized).

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: A serial dot matrix printer is of the non-impact solid ink type has the ink 102 contained in a tubular container 100 provided at one end with a printing orifice 106. In order to facilitate replacement of empty container, the container is provided with a grip 103 fixed to its central zone, which fits into the space between two resilient fixing forks 95, 96 rigid with the printer carriage 48. The end of the container remote from the orifice 106 is closed by a cap 110 which engaged by an electric contact 116 and connects to the ink rod 102 through a spring 107, for establishing the operating voltage between the ink rod and a counter-electrode 89 in the form of a laminar spring guiding the paper 82 round a platen 80.

Abstract: The calculator is small enough and well protected enough to be carried in the pocket. In addition to a keyboard 28, circuit board 29, batteries 18 and an LCD data display 91, there is a printer comprising a platen 36 which draws paper from a roll in a compartment 101. A thermal printing head 33 is reciprocated along the writing line by a pin 44 engaging in an eccentric cam groove in a disc 46 rotated by a crown wheel 53 and a pinion 54 on the shaft of a motor. Another cam-follower pin 64 reciprocates a slide 66 which advances the platen incrementally after each traverse of the head 33. A slidable cover 14 is shown open, exposing the printing mechanism and operating a switch which enables the printer. Results appear on the LCD display and are printed. When the cover is slid closed it protects the printing mechanism and disables it via the switch. The calculator can nevertheless be used without the printer, results being displayed only on the LCD display 91.

Abstract: A non-impact printing method with selective emission of solid ink particles is disclosed. A rod of solid ink is spring-pressed in an insulating housing against an end wall with a nozzle therein. A pulsed high voltage applied between the ink rod and a counter-electrode (which can be behind a paper target) causes ink particles to be eroded from the rod and ejected through the nozzle onto the paper. The method includes incremental line-feed paper movement, movement of printing devices as just described along the printing line, and selective control of the high-voltage pulsing such as to form characters by a dot matrix technique.

Abstract: A solid ink cartridge for a non-impact printer with emission of solid ink particles is disclosed. A rod of solid ink is spring-pressed in an insulating housing against an end wall with a nozzle therein. A pulsed high voltage applied between the ink rod and a counter-electrode (which can be behind a paper target) causes ink particles to be eroded from the rod and ejected through the nozzle onto the paper. The printer includes incremental line-feed paper movement, movement of printing devices as just described along the printing line, and selective control of the high-voltage pulsing such as to form characters by a dot matrix technique.

Abstract: A non-impact printing device with selective emission of solid ink particles is disclosed. A rod 19 of solid ink is pressed by a spring 20 in an insulating housing II against an end wall with a nozzle 13 therein. A pulsed high voltage applied between the ink rod and a counter-electrode 16 (which can be behind the paper 25) causes ink particles to be eroded from the rod and ejected through the nozzle on the paper. Printers are described which employ incremental line-feed paper movement, movement of printing devices as just described along the printing line, and selective control of the high-voltage pulsing such as to form characters by a dot matrix technique.

Abstract: A dot matrix printing device for electronic calculator comprising a plurality of electrically heatable dots of an insulating plate aligned therebetween and spaced according to a constant pitch to print the digits of the calculator amounts. A symbol dot is located adjacently to the terminal digit dot which prints the least significant digit of the amount, aligned with the other dots of the plurality. The symbol dot is spaced from the terminal digit dot by a distance greater than the constant pitch of the other dots and prints the explanatory symbols of the amounts leaving a blank between the digits and the symbols of the amounts.

Abstract: A keyboard comprises a plurality of keys which, when depressed, elastically deform conductive laminae which thereby go with a snap action from a stable configuration to an unstable configuration to complete an electrical circuit associated thereto. Each lamina has the form of two mutually transverse pairs of parallel edge strips spanned by a diagonal strip and the edge strips have permanent bends set into them such that the diagonal strip is bowed in the stable configuration towards the corresponding key. A fixed contact on the lamina is located adjacent one end of the diagonal strip and a movable contact is located in the central region of the diagonal strip. A single key actuates two identical laminae, one through an actuator resiliently coupled to the key and the other through an actuator fixed to the key.

Abstract: An arrangement for detecting the angular position for a rotatable part, for example, the printing head of an office machine comprises a shaft coupled to the rotatable part for rotating in synchronism therewith, a first rotatable cylinder arranged to rotate with the shaft and having disposed along a circumferential track a plurality of recognition apertures which are associated with predetermined discrete angular positions of the rotatable part. A first detecting unit is arranged to co-operate with the plurality of apertures to detect the predetermined discrete angular positions of the rotatable part. A second rotatable cylinder is rotatably mounted inside the first cylinder and is coupled to the shaft through speed reduction gears. On the second cylinder there is disposed at least one synchronizing element co-operating with a second detecting unit to detect complete revolutions of the rotatable part.

Abstract: A dot-matrix printing device for a printing office machine, comprising a series of striking bars in the proximity of the recording medium movable transversely of the medium for printing dots in different locations. The bars are adapted to be actuated by the armatures of corresponding electromagnets for impressing individual dots of characters. The striking bars are guided in the proximity of the recording medium by a movable guide which effects the transverse movement and each electromagnet has a fixed core and a movable armature in articulated engagement with the corresponding bar. Each armature is provided with an actuating spring which tends to move the armature away from the core of the electromagnet.

Abstract: A cartridge for endless magnetic tape loops including a cover containing a pair of supports substantially coplanar with the other and between which is wound a magnetic tape in lengthening coils. A third support guides a connecting coil which connects the innermost coil with the outermost coil of the loop. The third support is substantially coplanar with the pair of supports in such a way that the connecting coil is substantially coplanar with the other coils of the tape recording and/or reading device for a magnetic tape contained in a cartridge which includes at least one window through which the tape contained therein may be reached. The device includes a capstan, a pressure roller and a magnetic recording and/or reading head mounted on an activation lever. A spring element normally holds this lever against the action of a pressure spring.

Abstract: An electronic keyboard comprises a plurality of depressable keys each one of which comprises a stem normally movable and connected through a spring to a metallic actuator. Each actuator is lodged in a supporting element jutting out from the stem and cooperates with a permanent magnet which retains it in a rest position. Upon the depression of a key, the corresponding spring is loaded and after a predetermined displacement of the key a shoulder of the supporting element cooperates directly with the corresponding actuator disengaging it from the permanent magnet. The actuator is then pushed by the action of the spring to a movable contact of an electronic switch which generates an electrical signal.