FR2622510A1 - DEVICE FOR PRINTING CHARACTERS PLACED ON A CARTRIDGE OF THE TYPE SUPPORTING ALL THE CHARACTERS AND SIGNS OF A PRINTING MECHANISM - Google Patents

Abstract

A printing carriage 1 can be moved back and forth in front of a printing cylinder 9 and in particular carries a motor 3. This motor controls, via a cam 5, the movements of a hammer. printing 6 acting on the characters 7 carried by the fingers of a character wheel 8. According to the invention, the same motor 3 is also used to drive one or more other functions, such as transporting the ink ribbon, for example by means of an eccentric 12, an oscillating lever 14 and a pawl 17 acting on a ratchet wheel 18. In addition to a reduction in the moving masses, a considerable reduction in the cost of the mechanism is thus obtained. printing. The invention is particularly applicable to typewriters.

Description

The object of the invention is a device for printing characters

  arranged on a character holder of the supporting type

  all the characters and signs of a printing mechanism, the impres-

  this is done by means of a motor running in a start-stop mode. Traditionally, typewriter manufacturers have striven to keep moving masses as low as

  possible. This is especially true for typewriters

  carrying a character carrier such as a character wheel, arranged on a carriage movable in translation along the printing cylinder. Typically, the character wheel is indexed, i.e. rotational printing position, by means of a motor, while the printing is produced by means of an electromagnet. Proposals have however been made already

  to produce printing by a cam driven by a motor.

  Proposals of this nature are contained in the documents DE-AS 18 07 387, DE-OS 21 01 995 and DE-PS 27 17 975. In particular in the two documents mentioned last, we see that the total mass of the truck can to be kept relatively low due to the fact that the motor for the drive of the cam is placed in the frame of the machine. However, as its rotational movement must be transmitted to the truck, it is necessary to provide considerable additional resources for this purpose. These two known devices require

  in addition to a control electromagnet or synchronization system

  tion, so that the overall cost of such a typewriter is

relatively high.

  * The object of the invention is to allow a reduction

  additional mobile masses on a machine

  positive as defined at the beginning, in particular on a typewriter, by a simple mechanical construction. For this purpose, according to wo the invention, a device as indicated at the beginning is characterized in that the motor is arranged to ensure, by means of an eccentric and an oscillating lever, the drive for additional functions for example for transporting an ink ribbon. Since the motor for printing the successively selected characters - can also provide training for other functions, special drive systems, such as motor or electromagnet, can be dispensed with for these functions. additional functions.

  In addition to the reduction of moving masses, eco-

  considerable benefits in the overall cost. In addition, the place released

  on the carriage (carrying the mechanism) of printing by the suppressor

  of the drive system, may be used for other purposes,

  for example to house a larger ink ribbon cassette.

  This gives a series of benefits that are in cause and effect and have a favorable influence on the construction

  of a typewriter.

  The attached drawing shows an exemplary embodiment of the invention by a schematic representation. The single figure in this drawing shows more specifically a side view of a printing carriage, but with omission of the drive motor for indexing the character wheel, so that the representation is

clearer.

  The printing carriage 1 is equipped with a post 2 on which is fixed a motor 3. On the shaft 4 of this engine is fixed

  a cam 5 for controlling a hammer 6 intended to produce the im-

  pressing a character 7 of the character wheel 8 - after the printing position of this character has been placed on the sheet of paper supported by the printing cylinder 9. At its rest position,

  the hammer 6 is applied by a spring 10 against a stop 11.

  In the exemplary embodiment shown, an excen-

  12 is seated in addition to the shaft 4 of the motor. Against this eccentric applies a roller 13 of an oscillating lever 14 whose oscillation axis 15 is also carried by the upright 2. A spring 16 tends to keep the roller 13 constantly in contact with

  eccentric 12. The upper end of the lever 14 carries a cli

  quet 17 that cooperates with a ratchet wheel 18 which is rotatably mounted on a portion 19 of the carriage 1. This wheel is

  provided with a coupling part 20 which penetrates into a case

  ink ribbon for example when such a cassette is

set up on the device.

  The rotation of the motor shaft 3 causes, via the cam 5, the movement of the hammer 6 towards the impression cylinder 9. The assembly is preferably carried out so that the hammer performs the last part.

  of his free flight movement. The rotation of the cam 5 is

  however, that of L'eccentrique 12. This one is

  the lever 14 against the action of the spring 16, which

  rotation movement at the ratchet wheel 18. This rotation movement

  tion is transmitted by the coupling part 20 to the ink ribbon.

  It can thus be seen that a single motor can provide training for several functions, that of the printing hammer and that of the ink ribbon in this example. The adequate conformation of the cam and / or the eccentric makes it possible without any difficulty to mutually offset the different movements over time so that they do not overlap. It thus becomes possible to use a motor of lower power, and therefore more economical, which

  results in further cost reduction.

  Different power modes for

  the engine 3 also make it possible to obtain different printing forces.

  for the hammer. However, such a provision must have no influence on the drive of the ink ribbon. Similarly, training for the second function can be derived from

  the cam 5, instead of the eccentric 12. The inversion of the rotation direction

  tion of the motor shaft 4 also makes it possible to obtain functions without there being superposition of movements. Rotations of the cam 5 and / or the eccentric 12 on parts of a lathe are

conceivable also.

  Of course, the rotary motion of the motor can also be used for functions other than those described here. It is thus possible, for example, to pull the lifting movement

  the cam's ink ribbon for the printing hammer, so

  3. The latter can also be used to produce the training of a correction tape. It can be seen therefore that a whole series of variants are possible, but all of which have the advantage of reducing the moving masses and of decreasing the cost in addition.

Claims (1)

CLAIM   Device for printing characters arranged on a character-type holder supporting all the characters and signs of a printing mechanism, printing being effected by means of a motor operating in a start-stop mode, characterized in that the engine (3) is arranged to provide, by means of an eccentric (12) and an oscillating lever (14), the drive for additional functions, for example for transporting an ink ribbon.