JPS6160771B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a type belt type impact printing device, and more particularly to a printing device designed to prevent wear of a type belt and a platen.

The platen of a type belt type impact printing device is exposed to the sliding of the type belt, the impact force of the printing hammer, and the sliding friction during impact contact, so wear is inevitable.

Platens made of hardened steel plated with chromium or nickel do not have sufficient wear resistance, and platens sprayed with carbides such as tungsten are undesirable because they cause wear of the type belt. When lubricating oil is supplied to the hardened steel platen, the sliding resistance due to the viscosity of the lubricating oil becomes noticeable, and the output of the drive motor that drives the type belt must be extremely large, and the excess lubricating oil flows into the ink ribbon. There is a problem that the print quality deteriorates due to adhesion to the paper.

Even if the platen is coated with a solid lubricant such as graphite or polytetrafluoroethylene (hereinafter referred to as PTFE), the coating life is not sufficient. When the platen wears out, the striking force of the printing hammer is not effectively used, and the belt speed fluctuates due to increased sliding resistance between the type belt and the platen, making it impossible to obtain good printing quality. Furthermore, wear of the type belt may lead to belt breakage, resulting in a large economic loss.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, extend the wear life of the platen and type belt in this type of printing device, and provide an economical and highly reliable type belt type impact printing device that requires less frequent maintenance and replacement. It is to be.

The present invention focuses on the fact that wear of the type belt and platen does not progress while a solid lubricant film such as PTFE, graphite, or molybdenum disulfide (MoS ₂ ) is interposed between the platen and the type belt. The present invention is characterized in that the solid lubricant is prevented from disappearing from the sliding surfaces of the type belt and the platen. The present invention will be explained below with reference to the drawings.

An endless type belt 1 made of a thin metal strip and having a group of type characters on its surface is attached between a driving pulley 4 and a driven pulley 5 that rotate clockwise, and slides on a platen 2 while passing in front of a printing hammer 3. pass. The printing hammer 3 collates the printed characters passing in front of it for each digit, and when the printed characters to be printed pass in front of it, it hits the printed characters via printing paper and an ink ribbon (not shown). The platen 2 receives the impact of the printing hammer 3. A solid lubricant block 6 made of PTFE or the like, which has a small coefficient of friction and a large amount of specific wear, is provided on the sliding surface side of the platen 2, and is pressed against the back surface of the type belt 1 by a pressing spring 7. Therefore, the solid lubricant in the block 6 wears off little by little and adheres to the back surface of the type belt 1, and as the type belt 1 moves, the attached solid lubricant is carried to the platen 2, where it is removed from the platen. 2 and the type belt 1, and prevents the platen 2 and the type belt 1 from coming into direct contact.

If the platen 2 is made of ceramic such as aluminum oxide (Al ₂ O ₃ ), wear of the platen 2 itself will not be a problem due to its high hardness and melting point.
On the other hand, ceramic has fine particle surfaces on its surface, which try to bite the type belt 1 and cause abrasive wear, but the solid lubricant buries the fine particle surfaces of the platen 2, and the solid lubricant Since the printing agent is supplied one after another from the printing agent block 6, wear on the type belt 1 is kept to a slight level. It is further preferable that the platen 2 is subjected to pretreatment such as rubbing the same type of solid lubricant before assembly.

As described above, according to the present invention, the solid lubricant is attached to the back surface of the type belt, and the lubricant is carried to the platen and interposed between the platen and the type belt. Wear can be prevented, and as a result, an economical and highly reliable printing device can be provided.

[Brief explanation of the drawing]

The figure is a plan view showing an embodiment of the type belt type impact printing device of the present invention. In the figure, 1 is a type belt, 2 is a platen,
3 is a printing hammer, 4 is a driving pulley, 5 is a driven pulley, 6 is a solid lubricant block, and 7 is a pressing spring.

Claims (1)

[Claims] 1. A type belt made of a thin steel plate and running horizontally along the printing position, a plurality of printing hammers arranged in line along the printing position, and facing the printing hammers via the type belt. The printing device has a platen extending along the printing position, and includes a solid lubricant block and a pressing means for pressing the solid lubricant block against the back surface of the type belt, so that the solid lubricant block is attached to the back surface of the type belt. A printing device characterized in that the solid lubricant is conveyed to the platen as the type belt moves, and the solid lubricant is interposed between the type belt and the platen. 2. The printing device according to claim 1, wherein the solid lubricant block is formed from any one of graphite, polytetrafluoroethylene, and molybdenum disulfide, or a mixture thereof. 3. The printing device according to claim 1, wherein the pressing means is a spring that presses the rear end of the solid lubricant block. 4. The printing device according to claim 1, wherein the platen is made of ceramic such as aluminum oxide.