EP0245640B1 - Exchangeable ink ribbon cassette for a printer - Google Patents

Abstract

In a replaceable ribbon cartridge (12) for printers in which the ribbon (14) can be guided out of the cartridge through an exit opening (16) and at the end of a tension segment extending outside the cartridge can be reintroduced into the cartridge through an entrance opening (18), there is arranged on the cartridge (12) in the zone of the tension segment at least one deflection slide (24, 26) displaceable in a direction approximately perpendicular to the ribbon plane between a position of retraction into the cartridge (12) and an extended position deflecting the ribbon (14). Through the deflection slide or slides (24, 26), the ribbon (14) is generally spread away from the cartridge sufficiently so that upon insertion of the cartridge into the printer, it places itself around the printer head. During the last phase of insertion, the deflection slides (24, 26) are retracted, as by means of rams (56) arranged on the printer, so that during the subsequent ribbon advance, the ribbon (14) can become tensioned in its guide.

Description

The invention relates to an exchangeable ribbon cassette of the type mentioned in the preamble of claim 1.

It has become generally accepted to place ribbon cartridges for printers and other comparable devices in cartridges, because this enables a quick and easy change of ribbon. In order to keep the ribbon taut in the printing area, the ribbon loop running outside the ribbon cassette in front of the print head of the printer must generally be laid around guide bars or around the front surface of the print head itself. It is therefore generally still necessary to thread the ribbon by hand into the guideway when the ribbon cassette is inserted, which complicates the insertion process and leads to the operator's hands being soiled by the strongly coloring ribbon.

A device is already known by means of which the ribbon is automatically placed around guide webs when the ribbon cassette is inserted and when the ribbon is subsequently transported (DE-OS 32 14 633). These guide webs are structurally relatively complex, since either a plurality of guide webs are mounted on each print head carrier in an exact mutual position or have to be integrally formed thereon, which, for example, complicates the shapes and the molding process.

US-A-4 352 575 already shows the features contained in the preamble of the new claim 1. The deflection slides, which can be displaced perpendicular to the ribbon plane between a retracted position and an extended position that deflects the ink ribbon, are part of a so-called adapter, which, for one-time use, is placed on the cartridge when the cartridge is first inserted into a printer and pushed into an extended position by hand. After inserting the cassette into the printer, the adapter is moved to its retracted position and removed from the cassette.

As can further be seen from the description, an alternative provides that the manufacturer installs the adapter on the cassette, but the user has to remove it himself; in another alternative it is provided that the user both assembles and disassembles the adapter himself. In both cases, the user has a tedious manipulation that requires a certain manual skill when inserting the cassette into the printer. The entire design of the known cassette or the deflection slide indicates that the adapter is only intended for single use when the cassette is inserted for the first time, so that this known cassette does not meet the modern requirements for reusable consumer goods, but rather in the category of Disposable article heard.

It is the object of the invention to provide an ink ribbon cassette of the type described in the preamble of the new claim 1, in which the deflection slide is a functional part of the cassette which can be used again and again form, which can be handled easily and without special manual skill and which in particular makes it possible, according to a further embodiment, to also realize an automatic actuation of the deflection slide.

This object is achieved by the features described in the characterizing part of the new claim 1.

The ribbon loop extending outside the cassette is spread so far away from the cassette by the extended deflection slide (s) that it lies around the front surface of the print head or any guide webs that may be present. The deflection slides are then moved into their retracted position so that the ink ribbon tensions along the guideway during the subsequent transport. To remove the cassette, the ribbon is again lifted from the front surface of the print head or from the guide webs by extending the deflection slides.

The deflection slides are permanently attached to the cassette, i.e. they form an integrated functional part of the cassette.

The deflection slides are elastically biased in the direction of extension so that the cassette is ready for use, i.e. is ready to be inserted into the printer. After insertion or during automatic operation in a late phase of insertion, the deflection slides are withdrawn so that the ribbon takes the course desired when printing.

In a preferred embodiment of the invention, that a deflection slide is arranged in the running direction of the ribbon behind the outlet opening and in front of the inlet opening. In this way, the ink ribbon is lifted off essentially over its entire span extending outside the cassette, which further facilitates the so-called threading process.

In a further embodiment of the invention, each deflection slide is designed as a three-part web, the sections of which are connected to one another via joints. A first section of this web is firmly anchored in the cassette; the second section is pivotally attached to the first and interacts with a pivot actuating plunger. A third section is linearly displaced by the second section. This represents the actual element that deflects the ink ribbon. The three-part web is preferably formed in one piece from a flexible material, the joints connecting the sections being designed as so-called film hinges. Such deflection slides can be produced in a simple and inexpensive manner as plastic parts.

In a further embodiment of the invention, the deflection slides are actuated by pivot actuating plungers which can be inserted into the inside of the cassette through openings formed in the cassette and thereby pivot the second section of the deflection slider. It is preferably provided that the deflection slide consist of an elastic material, that they assume their extended position in an elastically relaxed state and that they can be adjusted into an elastically tensioned, retracted position by the actuating plunger. The pivot actuating plungers are arranged as fixed in the cassette holder of the printer, pins inserted into the openings formed on the ribbon cassette when the ribbon cassette is inserted. The ribbon is therefore spread apart from the cassette in the normal state and ready for insertion. When the cassette is inserted, the pins penetrate the cassette and in the last phase of the insertion process the deflection slides are withdrawn, so that the ink ribbon lies against the guide webs provided or the front surface of the print head.

Fig. 1

eine Draufsicht auf einen Druckkopf sowie auf eine Farbbandkassette, bei der die obere Deckwand fortgelassen wurde;

Fig. 2

eine perspektivische Darstellung eines Auslenkschiebers der in Fig. 1 verwendeten Art im nichteingebauten Zustand;

Fig. 3

bis 6 verschiedene Ansichten eines Auslenkschiebers gemäß Fig. 2;

Fig. 7

eine perspektivische Darstellung eines Auslenkschiebers gemäß Fig. 2 im eingebauten Zustand.

Further advantageous refinements emerge from the subclaims and the description which now follows. In this an embodiment of the invention shown in the drawing is described in more detail. Show it:

Fig. 1

a plan view of a print head and an ink ribbon cassette, in which the upper top wall has been omitted;

Fig. 2

a perspective view of a deflection slide of the type used in Figure 1 in the non-installed state.

Fig. 3

to 6 different views of a deflection slide according to FIG. 2;

Fig. 7

a perspective view of a deflection slide according to FIG. 2 in the installed state.

In the illustrated embodiment, the invention is explained using an ink ribbon cassette for a dot matrix printer. 1 shows a needle print head 2 with a drive part 4 and a needle guide part 6 directed towards the printing plane. The needle print head 2 is fastened in a conventional manner on the print head carrier of a printer, not shown in detail. The printing plane runs at a short distance from the Front surface 8 of the needle guide part 6 perpendicular to the plane of the drawing.

A conventional ink ribbon cassette 12, which accommodates the needle print head 2 in a recess 10, is likewise placed on the print head carrier. It takes up an ink ribbon 14 which is led out of the ink ribbon cassette 12 from an outlet opening 16 and is reinserted through an inlet opening 18. In the example shown, it is, for example, an ink ribbon cassette in which the ink ribbon 14 is arranged in numerous loops in a storage space 20, as need not be shown in more detail.

In the area between the outlet opening 16 and the inlet opening 18, the ink ribbon 14 runs outside the cassette; this area is referred to below as the span. The ribbon is held taut on this stretch so that it can be moved along the writing plane without wrinkles. The direction of the ribbon is indicated by arrow 22.

In the direction of travel behind the outlet opening 16 and in front of the inlet opening 18, a deflection slide 24, 26 is arranged, which are arranged approximately perpendicular to the ribbon plane between a position retracted into the ribbon cassette 12 and an extended position, which deflects the ribbon 14 out of its normal path. Both deflection slides 24, 26 are actuated simultaneously and in the same direction, so that both deflection slides are retracted or extended. Only to simplify the drawing, the deflection slide 24 is shown in the retracted position, the deflection slide 26 in the extended position, in FIG. 1.

When the ink ribbon cassette 12 is placed on the print head carrier, both deflection slides 24, 26 are in the extended position, so that the ink ribbon 14 is spread so far forward that it lies in front of the front surface 8 of the needle guide part 6 without getting caught on it. The ink ribbon 14 follows the course shown on the left side of FIG. 1 in a continuous line, on the right side in a dashed line.

Only in the last phase of the touchdown movement are the deflection slides 24, 26 moved into their retracted position so that the ink ribbon 14 can stretch around the front surface 8 of the needle guide part 6; it then follows on both sides of a path, as shown in Fig. 1, right side with a solid line.

The deflection slides 24, 26 each consist of a three-part web of the shape shown in perspective in FIG. 2. This web has three sections, which are each connected to one another via joints. The first anchoring section 28 is firmly spread in the cassette. The second actuation section 30 is pivotally connected to the anchoring section 28 via a hinge-like joint 32 and interacts with a pivot actuation plunger, as will be explained in more detail further below. The third deflection section 34 is pivotally connected to the actuation section 30 via a hinge-like joint 36 and is driven by the latter to a linear displacement movement.

Two pivot bearing journals 37 and two ramp-like actuating surfaces 38 are also formed on the actuating section 30. A stop pin 40 is located on the deflection section 34 intended. The mode of operation of the deflection slide 24, 26 is explained in more detail below.

The deflection slide 24, 26 is formed in one piece and preferably consists of an elastic plastic material. The joints 32, 36 are formed by thinned material areas, so-called film hinges. Fig. 3 shows a deflection slide 24, 26 in a side view.

FIG. 4 shows a cross section in the area of the actuation section 30 along the line IV-IV in FIG. 3. In particular, the ramp-like actuation surfaces 38 and the pivot bearing journals 37 can be clearly seen.

FIG. 5 shows a top view of a deflection slide 24, 26 corresponding to the viewing direction V in FIG. 3. It can be seen in particular that the axis 42 of the pivot bearing pin 37 coincides with the theoretical axis of the joint 32. The axis 42 represents the pivot axis for the actuating section 30.

Fig. 6 shows a longitudinal section along the line VI-VI in Fig. 3. In this figure it can be seen that the joints 32, 36 are each formed as film hinges with a lower material thickness, wherein the hinge webs are each formed on different sides of the deflection slide corresponding to the bending direction shown in FIGS. 1 and 7.

As can be seen in FIGS. 1 and 7, the pivot bearing journals 37 are pivotably mounted in journal receptacles 44 in the bottom 46 of the cassette and (as was not shown in more detail) in the top surface of the cassette in the direction of the arrow 48.

The anchoring section 28 rests resiliently against a material web 50, so that the actuating section 30 is prestressed in the sense of an extension of the deflection section 34. The deflection section 34 is guided in the direction of arrow 52 between two guide webs 54. The extension path is limited by the stop pin 40 resting on one of the guide webs 54.

A pivot actuating plunger 56 is assigned to each deflection slide 26 and is attached to the print head carrier. When the ink ribbon cassette is placed, these pivot actuation plungers 56 each penetrate through openings 58 in the base 46 of the cassette and come to rest against one of the ramp-like actuation surfaces 38, as a result of which the actuation section is pivoted in the manner of retracting the deflection section 34.

The design of the pivot actuating plunger 56 and the actuating surfaces 38 is selected such that the actuating section 34 is only retracted in the last phase of the placement movement of the ribbon cassette on the print head carrier. The pivoting movement of the actuating section 30 in the sense of retraction is limited by a stop pin 60.

5, each deflection slide is symmetrical with respect to a plane perpendicular to the drawing plane, which contains the division line VI-VI, so that each deflection slide is suitable for an arrangement on both sides of the needle guide part 6.

Claims (10)

1. A replaceable ribbon cartridge for printers of the type in which the ribbon (14) can be guided out of the cartridge through an exit opening (16) and, at the end of a span distance stretching outside the cartridge, can be reintroduced into the cartridge through an entrance opening (18), and wherein at least one deflection slide (24, 26) is provided on the cartridge (12) in the area of said span distance, the deflection slide being moveable generally perpendicular to the ribbon plane between a retracted position and an extended position deflecting the ribbon (14), characterized in

   - that the deflection slides (24, 26) are mounted on the cartridge (12) in an undetachable manner and are elastically biased in the extending sense, and

   - that means (56) are provided for moving the deflection slides (24, 26) to a retracted position within the cartridge (12) against the action of the elastic biasing means.
2. The ribbon cartridge of claim 1, characterized in that two deflection slides (24, 26) are arranged, one behind the ribbon exit opening (16) and one ahead of the ribbon entrance opening (18) in the direction of advance of the ribbon.
3. The ribbon cartridge of claim 1 or 2, characterized in that each of the deflection slides (24, 26) is generally defined by a web having a section (34) arranged transverse relative to the ribbon plane and having a width essentially corresponding to the ribbon width.
4. The ribbon cartridge of claim 3, characterized in that each of the deflection slides (24, 26) is preferably defined as a web including three sections and disposed generally symmetrical with respect to a plane extending parallel to the main plane of the cartridge, the sections (28, 30, 34) of the web being connected with each other by joints (32, 36), the first section defining an anchoring section (28) fixedly arranged in the cartridge (12), the second section defining an actuation section (30) adjacent said anchoring section and arranged so that it can swivel in the cartridge main plane, being perpendicular to the ribbon plane, the third section defining a linearly displaceable deflection section (34) and wherein swivel actuation rams (56) are provided cooperating with the actuation section (30).
5. The ribbon cartridge of claim 4, characterized in that the deflection slide (24, 26) is formed in one piece of flexible material and wherein the joints (32, 36) are formed as hinges with a thinner material cross-section arranged between the sections (28, 30, 34) with thicker cross sections.
6. The ribbon cartridge of claim 4 or 5, characterized in that the cartridge (12) includes openings formed therein (58) through which swivel action rams (56) can be introduced into the cartidge interior.
7. The ribbon cartridge of any one of claims 4 to 6, characterized in that the actuation section (30) is provided with swivel bearing journals (37) which are retained in journal retainers (44) formed in the cartridge.
8. The ribbon cartridge of any one of claims 4 to 7, characterized in that the actuation section (30) includes at least one ramp-like actuation surface (38) formed thereon, which is inclined relative to a reference plane extending perpendicular to the cartridge main plane, that the swivel actuation rams (56) are defined by pins which are moveable in the reference plane relative to the cartridge (12) and engage the actuation surface (38), the pin preferably being fixedly arranged in the cartridge retainer of the printer and, upon insertion of the ribbon cartridge, penetrating the ribbon cartridge through the openings (58) formed therein.
9. The ribbon cartridge of any one of claims 5 to 8, characterized in that the deflection slides (24, 26) are composed of an elastic material, the deflection slides (24, 26) being in an elastically untensioned state in their extended position and being in an elastically tensioned state upon displacement thereof by the actuating rams (56) to their retracted position.
10. The ribbon cartridge of any one of claims 4 to 9, wherein the cartridge (12) is provided with stops (60) to limit the swivel angle of the actuation section (30) and with guide webs (54) arranged perpendicular to the cartridge main plane and adapted for linearly guiding the deflection sections (34).

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