JPS597582B2 - How to make printing discs - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing printing discs and the finished printing disc product thereby, and more particularly to a composite printing disc structure having the characteristics necessary for high-speed, high-quality printing.

Achieving high speed printing disks requires that the disk arms be extremely flexible and have a light weight to absorb rapid printing shocks.

Many flexible lightweight plastics are available for this purpose. However, if high quality printing becomes an additional requirement, it is necessary that the type face of each arm of the disc be constructed of a hard and durable material. "Hard" used here
Alternatively, the term "rigid plastic" refers to a material with a high Young's modulus and high compressive strength. Because the material requirements for high-speed printing and high-quality printing are diametrically opposed, a compromise was originally sought for disk materials.

However, numerous test results show that a sufficient compromise was not achieved.

It has also been found that it is not possible to coat the typeface of the arm without significantly impairing the crispness of the type image. Furthermore, methods of electroforming metallic coatings onto flexible plastic type heads have not always been completely satisfactory. The reason for this is that a relatively small number of impacts can cause large cracks in the metal. Pure metal print heads mounted on plastic arms have not been satisfactory. Although metal printheads had the necessary structural strength, they were too heavy and unsuitable for high speed printing. The composite printing disk structure of the present invention aims to provide a disk that can operate at high speed and print with good quality. The present invention is a composite plastic and metal structure constructed in a novel manner.

The hub of the printing disk with radially extending arms is made of a flexible plastic, such as an acetal homopolymer or an acetal copolymer. The type is each located in a separate printhead base secured to the end of the arm. The base member is comprised of a hard durable plastic such as glass-filled polysulfonate or urea. The typeface of each printhead member is coated with a 0.001 inch layer of metal. This metallization is covered with a nickel layer and finally consists of a chrome-coated copper plate. The structure described above consists of a first injection molded or compression molded annular ring having a set of inwardly extending letters.

The type is individually placed on a printhead base which also includes a combination extension. The printing disk base is then injection molded. The arms have openings at their ends for receiving respective mating extensions. The mating extension is press fit in its entirety into the opening. The area surrounding the aperture may be heated before or after insertion of the mating extension into the aperture to soften the plastic and ensure a secure fit. The plastic can be heated by conventional methods or using ultrasound. After connecting the base member to the arms of the disc, the annular ring is removed from the plastic composite structure by cutting.An object of the present invention is to provide an improved printing disc.

Another object of the present invention is to provide a new multi-component printing disc and method of manufacturing the same.

Yet another object of the present invention is to provide a high speed printing disk that produces high quality printing.

The above and other objects of the invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

Referring now to FIG. 1, a first injection molded or compression molded member is shown.

This member is, for example, (a) polysulfone, (b) urea,
(c) nylon, (d) epoxy, (e) phenol,
(f) Can be molded from a filler such as melamine. This first molded piece has an annular ring-shaped portion 9 and a plurality of inwardly extending printhead base members 10. A typical printhead base member 10 is seen in FIG.

The print head is attached to ring 9 by fingers 11. The printhead has a typeface 12 on one side;
It has a combination extension 14 on the other side.

FIG. 2 shows a second injection molded disk-shaped member having a hub 15 and a plurality of flexible radially extending arms 16. FIG.

The ends of the flexible arms each include an opening 17 as shown in FIG. The mating extension 14 of the printhead 10 is generally press fit into the opening 17 of the flexible arm member 16 as indicated by arrow 18 in FIG. The resulting composite structure is shown in FIG. This second molded member is, for example, (a) an acetal homopolymer, (b) an acetal copolymer, (c)
Can be injection molded from materials such as poly"propylene.

The material used for the disc-shaped member needs to be highly flexible to withstand multiple printing impact cycles. The material used for the print head is high print resolution (Highpr
It is necessary that the material be hard and durable so that it exhibits excellent durability.

After press-fitting the print head 10 and arm 16,
The area around the resulting combination is heat treated to soften the plastic and create a tighter fit. Also, the plastic around the aperture and/or the mating extension can be heated for a period of time prior to insertion of the extension 14 into the aperture 17 to create an even greater retention force. If the first molded member were to be molded from an acetal homopolymer, the area around the opening 17 would be heated to approximately 149°C (3
Heat to 00'F). This is the temperature at which the acetal homopolymer softens. This material was heated at approximately 160℃ (3
Care must be taken not to overheat to 201F. This is because at this temperature the acetal homopolymer begins to deform. If the two combined parts are heat treated so that one or both of the plastic materials begins to soften, the combined holding strength increases. Heating of the plastic material can be accomplished by conventional methods or by using ultrasound to generate heat within the material.

After joining the two separately molded parts of FIGS. 1 and 2, the finger 11 is cut from the print head 10 approximately at the point 20 (see FIG. 5) to form the annular ring 9 (see FIG. 3). from the disc-shaped member (arrow 19 in Figure 4).

The resulting structure is a completed composite printed disk (fourth
This is arrow 25) in the figure.

Each printhead 10 is coated with a layer of metal.

This is done not only to improve the durability of the typeface 12 but also to improve its appearance. It will be apparent to those skilled in the art that modifications to the manufacturing process or composite structure of the disc and the use of other materials for the disc will readily occur to those skilled in the art. For example, printhead combination extension 14 could be designed as a single or double pin extension extending from coupling surface 21 (FIG. 5). Therefore, the scope and spirit of the invention should not be limited by any obvious variations, but the invention should be construed in the context of the appended claims.

[Brief explanation of drawings]

FIG. 1 is a plan view of a first molded member of a printing disc composite structure according to the invention comprising an annular ring containing a set of type characters; FIG. A plan view of the second molded member of the printing disk structure; FIG. 3 is a plan view of the first and second molded members joined;
FIG. 4 is a partial perspective view with a portion of the first molded member of the composite printing disk of the present invention removed, and FIG. 5 is an enlarged perspective view showing a typical print head in combination with the corresponding arm of the disk-shaped base. It is a diagram. In the figure, reference numeral 10 indicates a print head basic member;
12 is a typeface, 15 is a hub, and 16 is a flexible arm.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a printing disk for use in a printing device, comprising: a. an annular ring member; and a set of type letters provided at a location extending inward from the annular ring member; forming a first member comprising a plurality of printhead bases each having a typeface, a bonding surface on the back side of the typeface, and a connecting extension extending outwardly from the bonding surface; and b. a disc-shaped base and a plurality of arms extending radially from said disc-shaped base to provide one arm for each of said printhead bases, each outward extension thereof; a second end comprising an arm having an opening for receiving a corresponding connecting extension of each said printhead base;
molding the members; c. inserting each connecting extension into a corresponding arm opening to form a respective printhead base in each arm to form a composite structure between said first and second members; d. removing said annular ring member from said composite structure to form a printing disc. 2. A method for manufacturing a printing disk as claimed in claim 1, including the step of: 2 coating the first member with a metal layer at least around the typeface of the printhead substrate.