US 4,051,942 AGranted

Printing apparatus

AssigneeAlps Electric Co., Ltd.

InventorsTakeo Suzuki, Ikutaro Inoue, Hideo Tamai, Masatsugu Aoki

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Abstract

A printing apparatus for an electronic calculator or the like comprises a first type wheel formed with mathematical operator symbols which is fixed to a spline shaft and a second type wheel formed with digits which is slidably mounted on the spline shaft for integral rotation. A stepping motor rotates the spline shaft for character selection. A carriage is connected to the second type wheel and is movable by a cable wound around drive and take-up spools to move the second type wheel along the spline shaft for serial feed. A single electrical solenoid actuates a printing hammer for printing and subsequently actuates a ratchet and pawl mechanism to serially feed the second type wheel by one character position in one reciprocation of the solenoid plunger. A linkage initially connects the plunger to a first printing hammer associated with the first type wheel to print the mathematical operator and subsequently to a second printing hammer associated with the second type wheel to serially print digits from least significant to most significant.

Claims10

Dependent claims

A printing apparatus comprising:

a rotatable spline shaft;
a first type wheel fixedly mounted on the spline shaft, the first type wheel being formed with a plurality of first type symbols on the circumference thereof;
a second type wheel longitudinally slidably mounted on the spline shaft for unitary rotation therewith, the second type wheel being formed with a plurality of second type symbols on the circumference thereof;
type selector drive means for rotating the spline shaft and thereby the first and second type wheels for type symbol selection;
stepping drive means for steppingly moving the second type wheel along the spline shaft from a first position to a second position;
a first printing hammer movably disposed adjacent to the first type wheel;
a second printing hammer movably disposed adjacent to the second type wheel, the second printing hammer extending between the first and second positions;
reciprocating drive means having reciprocating actuator member connected to the stepping drive means;
and
hammer selector means for selectively connecting one of the first and second printing hammers to the actuator member in such a manner that the actuator member moves the selected one of the first and second printing hammers to strike the respective one of the first and second type wheels for printing when the actuator member is moved in a first direction and actuates the stepping drive means to move the second type wheel along the spline shaft by one step when the actuator member is moved in a second direction which is opposite to the first direction.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/731,460Filed 12 Oct 1976
Priority: JA 50-12278711 Oct 1975
Granted: 4 Oct 1977
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

B41J 19/20
Character-spacing or back-spacing mechanisms; Carriage return or release devices therefor: positive-feed character-spacing mechanisms
B41J 1/50
Types or dies fixed on wheel, drum, cylinder, or like carriers: with one or more carriers travelling across copy material in letter-space direction
B41J 9/12
Of more than one hammer, e.g. one for each character position: each operating in more than one character position
B41J
Typewriters