JPH0410609Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a doctor blade for platens that cleans dirt on the surface of transfer drums (platen rolls) of copying machines, printers, etc. Conventionally, this type of blade usually has a plate-shaped single-layer elastic body attached to a metal fitting so as to protrude, and the tip of the protruding elastic body is brought into contact with the rotating roll surface to clean dirt on the roll surface. However, in this case, if the blade itself is too hard, there is a problem of damaging or abrading the platen roll, and conversely, if it is too soft, the blade itself deforms and cannot perform its function of cleaning dirt on the surface of the platen roll. There is. In addition, in blades that are made of a two-layer structure that integrates a soft part and a hard part, the molded product may warp due to the difference in molding shrinkage rates of the soft and hard materials, making it difficult to maintain straightness, which is the lifeblood of the blade. had difficult drawbacks. This invention focused on the above-mentioned problems and was devised to improve them.Its features are a soft elastic polyurethane material with a hardness of 40 to 70°, and a hardness of 96°.
The present invention is characterized in that a multilayer elastic structure is constructed by laminating the polyurethane hard elastic body described above and the same soft elastic body as described above to form a single unit, so as to be brought into contact with the platen roll. Hereinafter, specific embodiments of the doctor blade for platen according to the present invention will be described in detail with reference to the accompanying drawings. Figures 1 and 2 are side views showing one example of a doctor blade for platens according to the present invention, and in the figures, R is a platen roll made of a metal cylinder made of mild steel, aluminum, stainless steel, etc. and coated with an elastic material on the outer peripheral surface. shows. On the other hand, B is a doctor blade which is a main part of the present invention, and is a plate-shaped soft elastic body 1 made of polyurethane or rubber with a thickness of 2 mm and a hardness of about 40 to 70 degrees.
and polyurethane with a thickness of 4 mm and a hardness of 96° or more. The platen roll R is composed of a multilayer elastic structure in which a plate-shaped hard elastic body 2 made of rubber and a soft elastic body 3 made of polyurethane and rubber with a thickness of 2 mm and a hardness of about 40 to 70 degrees are laminated and integrated. The soft tip of the structure is placed in contact with the outer peripheral surface of the structure. Here, the hardness of each of the plate-shaped elastic bodies used is usually 40 to 70 degrees for soft elastic bodies and 96 degrees or more for hard elastic bodies, taking into account the thickness of the doctor blade, etc. It is possible to change the selection as appropriate. Note that the hardness indicates Shore A hardness. As mentioned above, when the doctor blade B, which is made of a triple-layered multilayer elastic structure, is used, when attaching it to the fixture M, the tips of the soft elastic bodies 1 and 3 are connected to the surface of the platen roll R at four points in total. It is installed and used in contact. As a result, when the platen roll R rotates in the direction of the arrow, the reinforcing effect of the hard elastic body 2 prevents deformation of the soft elastic body 1 due to contact with the platen roll R, and also prevents damage to the surface of the platen roll R. Dirt on the roll surface can be cleaned and removed smoothly. In addition, the blade B has its material, structural dimensions, and usage conditions.

Of course, the shape can be changed as appropriate depending on [rotation speed, pressing force], etc. As detailed above, the doctor blade for platen according to the present invention uses a polyurethane elastic body of each required hardness, a plate-shaped soft elastic body on the contact surface with the platen roll, and a hard elastic body in the center of the blade.
Since it is made of a well-balanced multi-layer elastic structure with a triple structure in which the plate-like surface that does not come into contact with the roll is made of a soft elastic material, there is no warpage like in conventional blades, and the ridgeline precision that can be said to be the lifeblood of a blade is achieved. This technology prevents deformation of the soft elastic body of the blade and damage to the roll surface due to contact with the roll surface when the platen roll is driven, making it possible to clean the roll surface more effectively. Therefore, the adhesion between the multiple layers is very good, and there is no risk of peeling, and even if the soft polyurethane wears out and the hard polyurethane comes into contact with the platen roll, unlike metal, it will not damage the roll. 4 of blades
The blade has a structure that allows the use of a portion of the blade, making it a more practical platen doctor blade than conventional blades.

[Brief explanation of the drawing]

1 and 2 are side views showing examples of a doctor blade for a platen according to the present invention. R...Platen roll, M...Mounting tool, B...
Doctor blade, 1...soft elastic body, 2...hard elastic body, 3...soft elastic body.

Claims (1)

[Claims for Utility Model Registration] 1. In a doctor blade that is attached in contact with the platen roll, the blade is made of a soft elastic polyurethane material with a hardness (Shorer A hardness, the same applies hereinafter) of 40° to 70°, or a hard polyurethane material with a hardness of 96° or more. A doctor blade for a platen, characterized in that it is formed of a multilayer elastic structure in which an elastic body and the polyurethane soft elastic body are laminated and integrated, and the soft elastic body is configured to come into contact with the platen roll surface. . 2. A doctor blade for a platen according to claim 1, which has a soft elastic body protruding from both the front and back sides, allowing use at four locations on both sides.