JPH028789Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to percussive serial or line printer mechanisms, and more particularly to ribbon cartridges and platen members used in such printers.

[Prior art]

Various ribbon cartridges are known, but
They are divided into two categories. One of them is
From reel to reel inside the cartridge,
One of the reels engages with a power source located outside the cartridge to wind up the ribbon. Such ribbons are typically moved across the print area to provide a fresh ink surface between the impact printer and the print medium, such as a sheet of paper. Note that the print media is positioned in front of a suitable platen that is an integral part of the printer.

A second category of conventional ribbon cartridges are those designed to contain continuous loops of ribbon. The ribbon, which may or may not be twisted to form a Möbius strip, is contained within a cassette or cartridge body. Within either the cartridge or the printer, means are provided for withdrawing the ribbon from the cartridge, feeding it through the printing area between the platen and impact member, and returning it to the cartridge. The means include drive means and the like for compactly packing the ribbon into the cartridge body in a haphazard or tortuous manner.

Both of these prior art ribbon cartridge categories contemplate being suitably coated with an ink-impregnated ribbon or web or carbon film. Both categories also use a platen that is an integral part of the printer. After the ribbon is withdrawn from the cartridge, it must be stamped between the impact member and the platen while traveling outside the cartridge body. Such ribbons or webs undergo continuous wear during printer operation and are often replaced during the life of the printer. A typical ribbon has a lifetime of only two to six million prints. Printers that use such ribbons typically use precision-finished, expensive metal bars and meticulously formed resilient rollers and platens as shock-resistant components for the life of the printer. is in use.

When wire matrix printers are used, the platen members are also large and small metal bars or strips that are carefully machined to last the life of the printer. This is a fairly expensive component to manufacture. It also needs to be carefully aligned with the impact or printing member during installation in the printer. This is because it is necessary to maintain uniform density of printed characters. This need for precise assembly and adjustment significantly increases the overall cost of the printer.

Additionally, if a hard, wear-resistant surface is used as the material for the platen, the repeated strikes of the impact member create considerable noise, which is undesirable in many environments.

To reduce noise, metal platens have been coated with elastomeric materials to provide a resilient surface, but these materials are susceptible to wear and require frequent replacement of the expensive platen components.

[Purpose of invention]

In view of the above-mentioned problems with conventional ribbon cartridges and platens, an object of the present invention is to provide a replacement consisting of a cartridge and a platen in order to avoid the above-mentioned problems when the cartridge and platen are separate. The aim is to provide possible improved combination configurations.

Another object of the present invention is to provide an improved ribbon cartridge and platen combination configuration that has low noise generating characteristics.

[Summary of the idea]

The above objects of the present invention are achieved by the platen member being part of the ribbon cartridge. Typically, cartridges are manufactured from moldable plastics that are relatively hard and brittle, or soft and resilient, depending on the durometer of the material. Although it has been common practice in the past to construct cartridges from thermoplastic materials by conventional injection molding, the use of such materials as platens contained within the cartridge itself is an improvement. Not only can the high cost of a conventional platen as part of a printer be eliminated, but the platen can now have a lifespan comparable to that of a ribbon instead of a printer. Additionally, since the plastic material has approximately the same resiliency as a hard platen coated with an elastomer, noise is also significantly reduced. Although this platen surface wears out more quickly than a regular platen, it only lasts for the life of the ribbon, and the platen is replaced when the cartridge is replaced to provide a new source of ink. This platen is part of the cartridge and is formed of the same material as the cartridge. Means are provided for guiding the ribbon from the outlet of the cartridge body across its surface used as a platen and back into the cartridge in a conventional manner. The cartridge is modified in design to provide space for printing paper to pass between the ribbon and the cartridge platen if front side printing is desired. For multi-copy printing, i.e. high impact printing, the platen portion may be surfaced with metal, which provides a hard, abrasion resistant surface for the platen portion of the cartridge body. Positioning means may be provided for precisely aligning the cartridge and platen with the printing member so that the respective printing rows are parallel to the path of the printing member. This function can be provided by a locating hole that cooperates with a locating pin fixed at a precise location on the printer.

[Explanation of Examples]

FIG. 1 shows a plan view of a preferred embodiment of the present invention. Preferably, the cartridge body 1 is made of injection molded thermoplastic plastic, which is well known in the art. An ink-impregnated ribbon 2, contained largely within the body of the cartridge 1, is shown as a continuous or meandering, randomly packed loop. A guide arm or finger 3 extends from the body of the cartridge 1 for supporting the ribbon 2 at a distance from a platen surface 5 on a portion of its outer wall. Such spacing allows paper to be inserted between the ribbon 2 and the platen surface 5 on which printing occurs, and maintains alignment between the ribbon 2 and the platen surface 5 both vertically and horizontally. A guide pin positioning hole 4 is also illustrated. These holes cooperate with predetermined positioning guide pins fixed to the printer mechanism (not shown) to accurately position the platen surface 5 and cartridge 1 with respect to the scheduled printing line. (not shown).

Although the drive roller and pressure roller set 6 is shown built into the cartridge 1 in FIG. 1, a conventional stuffing roller may also be provided to draw the ribbon 2 into the main body of the cartridge 1. Those skilled in the art will understand. The ribbon exits the cartridge 1 through an opening near the opposite end of the cartridge. Since the details are well known to those skilled in the art, the explanation will be omitted. This example describes the stuffing roller type cartridge.
Those skilled in the art will readily understand that the present invention can also be used with cartridges in which the ribbon is wound from reel to reel. Important to the present invention is that the cartridge includes a platen and the structure in which the cartridge cooperates with the ribbon.

FIG. 2 is a longitudinal cross-sectional view of the structure of FIG. 1.

As shown in Figure 2, the cartridge body 1
has a hollow interior 7 for containing a tortuous stuffing ribbon or randomly folded ribbon as shown in FIG. 1, or for containing a reel.

The cartridge main body 1 has upper and lower main walls 12 and side walls 13, and the opposing inner wall surfaces of the main walls 12 are parallel to each other as shown, and spaced apart to accommodate the width of the ribbon. As shown in FIG. 1, the ribbon is accommodated in the interior space region 7 of the cartridge such that the width direction of the ribbon is substantially perpendicular to the inner wall surface of the main wall portion 12.

The ribbon 2 is supported on guide arms 3 at each end of the cartridge, as seen in FIG. A small gap 9 is also shown in FIG.
The center line 8 of the paper passes through it. The printing paper is passed between the back side of the ribbon 2 and the front side of the platen 5, and is stamped on the opposite side of the ribbon 2 by driving an impact member.

A centerline for the locating pin hole 4 is also shown, but as will be readily apparent to those skilled in the art, accurate alignment between the front surface of the platen 5 and the centerline of the locating hole 4 is not guaranteed during printing. In cooperation with precisely positioned pins, the platen 5 is accurately positioned parallel to the print line and print head (not shown).

As can be easily seen, the platen surface 5 is a directly exposed portion of the side wall of the cartridge 1, and is made of the same material as the cartridge, so-called injection molded thermoplastic. Such materials are more resilient and subject to greater wear than the hard machined steel or similar metal platens commonly used. However, in the present invention, since the platen only needs to last the life of the ribbon rather than the life of the printer, such a large degree of platen wear is not a big problem. This elasticity of the platen surface considerably reduces the noise caused by impact during printing, which is a derivative effect of the present invention.

Testing has shown that the faces of such plastic cartridges function very well as platens and do not experience abnormal wear until the ribbon is used up. but,
If very small dots are required, such as in high-precision, high-resolution matrix printing, the impact force or thrusting force may be quite large.
The platen 5 may be provided with a hard surface. Such a hard surface may be necessary if multiple copies are required, as they will generally be subjected to high impression forces. Still, plastic cartridges have the effect of reducing noise to some extent because their elasticity absorbs the force transmitted from their hard surfaces.

Referring now to FIG. 3, there is shown an enlarged view of a variation of the cartridge shown in FIG. In FIG. 3, the printing element is shown as an impact hammer or dot matrix printing member positioned adjacent to the side of the ribbon 2 opposite to where the platen surface 5 is positioned and along the centerline of the print. A member 10 is shown diagrammatically. Third
The platen surface 5 shown in the figures is shown as a metal insert. This insert is normally inserted into a predetermined location in the injection molding when the plastic 1 is injected to form the cartridge body. The metal surface 5 can withstand high stamping forces and does not add significant cost to the overall cartridge. Generally, a thin 22 or 24 gauge piece of cold rolled sheet steel or the like is sufficient to harden the platen surface to a degree comparable to the life of the ribbon 2.

Also shown are an aperture 9 into which a sheet along the centerline 8 can be inserted and a guide arm 3. The opening 4 of the locating pin is shown with its center line, as is the hollow part 7 of the cartridge.

The cooperative relationship of each component and the overall operation of the present invention have been clarified above. The positioning hole 4 is positioned accurately and with high precision with respect to the platen surface 5 on the surface of the cartridge 1. It then cooperates with precision positioning pins in the printer to align the platen surface 5 with the printing rows and printing members. As already pointed out, the elasticity of the platen reduces noise during printing. Additionally, injection molding the platen along with the cartridge during manufacture eliminates the cost of the entire stand-alone component of the overall printer construction in the form of a commonly used stand-alone platen. There is almost no additional cost if the platen is made of the same thermoplastic material and if the platen is formed on the surface of the cartridge. This is therefore very advantageous in providing a printer that is economical and has quiet operating characteristics.

The use of the cartridge surface as a platen member is not limited to the particular embodiments described above. This is because a cartridge of the type that feeds the ribbon from reel to reel can also be used in the same way.

Alignment or positioning means in the form of positioning holes 4 are precisely positioned with respect to the platen surface 5 which is part of the surface of the cartridge 1. They serve to position the platen in the printer, but they also serve to accurately position the ribbon relative to the intended print line. Therefore the ribbon,
The overall unitary construction of the guide means, platen, and cartridge body provides a compact, low cost, quiet operating characteristic, and easily replaceable structure for a variety of impact printers.

[Brief explanation of drawings]

FIG. 1 is a plan view from above of a ribbon cartridge including a platen according to an embodiment of the present invention, with the upper cover and wall section partially cut away to show the inside thereof. FIG. 2 is a cross-sectional view of the ribbon cartridge of FIG. 1. Figure 3 is similar to Figures 1 and 2.
It is a partially enlarged view of a modified version of the embodiment shown in the figure.
In particular, the drawings show positioning means that provide precise alignment of the platen surface and the printer. 1... Cartridge (main body), 2... (ink)
Ribbon, 3... Guide arm, 4... Guide pin positioning hole, 5... Platen surface, 7... Hollow part, 9...
…gap.

Claims (1)

[Claims for Utility Model Registration] (1) A main wall portion and a side wall portion having parallel opposing inner wall surfaces spaced apart from each other by a distance slightly larger than the width dimension of the elongated ribbon, and an internal space in the region of the inner wall surface. a housing formed of a plastic material, the inner space region containing a ribbon supply source such that the width direction of the ribbon is substantially perpendicular to the inner wall surface; The casing includes an opening provided in the side wall of the casing for the entry and exit of the ribbon, and an elongated flat platen that is integrally molded as a part of the casing on the side wall of the casing. a ribbon protruding from the casing inserts the paper along the length of the flat outer surface from one end of the flat outer surface and between the flat outer surface. a predetermined distance from said flat outer surface for guiding said ribbon so as to be able to advance said ribbon at a predetermined distance from said flat outer surface portion and then enter said housing through the other end of said flat outer surface portion; A ribbon cartridge, comprising: a ribbon guide means provided in a protruding manner; (2) The ribbon cartridge according to claim 1, wherein the flat outer surface portion is covered with a wear-resistant surface that is harder than the plastic material.