JP3555487B2 - Tube printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To upgrade the printing of a tube printer. SOLUTION: Brakes are installed on a thermal head 18 of a tube printer and a tube press roller 17 upstream of a platen roller 5 so that they are braked. The initial motion torque of the tube press roller 17 is smaller than the rotational torque of the platen roller, not forming obstacle for the tube feed by the platen roller, and when the platen roller is stopped rotating, the movement of the tube oversurface owing to expanding/contracting elasticity of the tube is checked. This hindrance of movement prevents turbulence of the printed letter patterns.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tube printer for printing on a soft vinyl tube, and more particularly to a tube printer with improved printing quality.
[0002]
[Problems to be solved by the invention]
Conventionally, in order to facilitate identification of a large number of wires connected to the terminal block of electrical equipment and to prevent erroneous connection, a vinyl chloride tube displaying the terminal number is placed over the end of the wire. Tube printers for creating number indicating tubes are known.
[0003]
In a tube printer, a platen roller and a thermal head sandwich a vinyl chloride tube and an ink ribbon, and the tube is crushed flat. Is thermally transferred.
[0004]
However, unlike a flat plate such as paper or resin tape, a tube printer that prints on a tube has a specific problem. That is, the tube is crushed flat by the platen roller and the thermal head and sent in a stacked state of upper and lower layers, but the upper layer with which the thermal head is in contact is lower than the lower layer with which the rotating platen roller is in contact. The frictional resistance is large, and the upper layer flows slightly shifted upstream from the lower layer when the tube runs. When the vehicle stops running, the upper layer slightly advances to catch up with the delay due to the elastic restoring force of the tube material.
[0005]
In other words, when the rotation of the platen roller stops, the amount of movement of the upper layer in contact with the thermal head is not synchronized with the rotation of the platen roller, and the timing of the stop is slightly, but slightly shifted. May cause problems such as missing dots and deformation of character patterns.
[0006]
Therefore, there arises a technical problem to be solved in order to improve the print quality by eliminating the asynchronousness of the running of the tube, and an object of the present invention is to solve the above problem.
[0007]
[Means for Solving the Problems]
The present invention proposes to achieve the above object, in which a thermal head is disposed on a platen roller, a soft vinyl tube is sandwiched between the platen roller and the thermal head, and the platen roller is rotated to run the tube. In a tube printer that prints on a tube with a thermal head, a tube press roller is disposed upstream of the platen roller and close to the platen roller, and the tube is pressed and crushed by the tube press roller and the platen roller. And a brake means for constantly braking the tube press roller to prevent movement of the upper surface of the tube due to displacement of the upper and lower surfaces of the tube when rotation of the platen roller is stopped. Providing a printer That.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a tube running system of a tube printer. A platen roller shaft 2 is provided at the front and rear center of a chassis 1, and idler roller shafts 3 and 4 are provided in parallel in front (right in FIG. 1) and behind the platen. A platen roller 5 is mounted on the roller shaft 2, and idler rollers 6, 7 are mounted on the front and rear idler roller shafts 3, 4. The platen roller shaft 2 is driven to rotate counterclockwise in FIG. 1 via a motor and a reduction gear device (not shown). Lever shafts 8 are respectively installed on the upper front part of the front idler roller shaft 3 and the upper rear part of the rear idler roller shaft 4, and a pair of left and right bell crank levers 9 are attached to the lever shafts 8. The pinch roller 10 attached to the tip is pressed against the idler rollers 6 and 7. The idler roller shaft 4 may also be engaged with the reduction gear train to perform synchronous driving with the platen roller 5.
[0009]
The lower ends of the front and rear bell crank levers 9 are respectively connected to the upper ends of the links 11, and the lower ends of the links 11 are pivotally attached to the lower part of the chassis 1. Then, a symmetrical expander cam 13 is attached to a cam shaft 12 provided below the central platen roller shaft 2, and the front part of the slider 14 </ b> F arranged in front of the expander cam 13 is located at the middle part of the front link 11. The rear end of the slider 14R connected to the rear of the expander cam 13 is connected to the intermediate portion of the rear link 11 to form a link mechanism, and the rotation of the expander cam 13 causes the front and rear sliders 14F and 14R to be symmetrical. The bell crank lever 9 is rotated by moving back and forth.
[0010]
Each of the front and rear bell crank levers 9 is provided with a spring (not shown) for urging the pinch roller 10 in a direction to raise the pinch roller 10, and the expander cam 13 is manually moved from the expanded position shown in FIG. When rotated 90 degrees, the distance between the front and rear sliders 14F and 14R decreases, the upper portions of the front and rear links 11 approach, the bell crank lever 9 rotates, and the pinch roller 10 separates from the idler rollers 6 and 7.
[0011]
In this state, the expander cam 13 is rotated by about 90 degrees, and the front and rear sliders 14F and 14R are spaced apart from each other as shown in FIG. Rotates downward, and the pinch roller 10 is pressed against the idler rollers 6 and 7. The sliders 14F and 14R are of a telescopic cylinder type with a built-in compression spring, and limit the contact pressure between the pinch roller 10 and the idler rollers 6 and 7 by the compression spring.
[0012]
A shaft 16 of an arm 15 is provided above the shaft 8 of the rear bell crank lever 9. A tube press roller 17 is attached to a shaft provided between the distal ends of a pair of left and right arms 15 extending forward. Is close to and opposed to the front outer peripheral surface of the platen roller 5. The tube press roller 17 is provided with a friction brake (not shown), and the initial dynamic torque of the tube press roller 17 is smaller than the rotational torque of the platen roller 5 and the expansion and contraction force of the tube when the tube feed is stopped. Is a value that does not rotate.
[0013]
The thermal head 18 is mounted in an upper cover 19 pivotally attached to a rear portion of the chassis 1. As shown in FIG. 2, when the upper cover 19 is closed, the thermal head 18 comes into pressure contact with the platen roller 5. Further, an ink ribbon cassette (not shown) is mounted in the upper cover 19 so as to hang around the thermal head 18. When the upper cover 19 is closed, the ink ribbon is sandwiched between the thermal head 18 and the platen roller 5.
[0014]
When loading the tube, open the upper cover 19, rotate the expander cam 13 by about 90 degrees as described above to lift the pinch roller 10 from the idler roller, and pull up the arm 15 by hand to pull the tube. It is passed through the lower surface of the press roller 17 and passed between the tube press roller 17 and the platen roller 5 for setting. Thereafter, when the lifting of the arm 15 is released and the tube press roller 17 is lowered as shown in FIG. 2, the tube TB is pushed by the tube press roller 17 and detours along the outer peripheral surface of the tube press roller 17. Is set to
[0015]
When the tube TB is fed in contact with the outer peripheral surfaces of the tube press roller 17 and the platen roller 5, the tube TB is crushed into a flat plate shape, and is printed while passing a position of the thermal head 18 while maintaining a flat state.
[0016]
As described above, the upper layer of the tube TB with which the thermal head 18 is in contact during printing has a higher frictional resistance than the lower layer with which the rotating platen roller 5 is in contact, and the upper layer of the tube TB is upstream of the lower layer. When the platen roller 5 stops rotating at the end of printing, movement of the upper layer of the tube TB is prevented by the tube press roller 17 on which the braking force of the brake is applied. . Therefore, after the rotation of the platen roller 18 is stopped, the upper layer of the tube TB does not slightly move forward, and the dot interval of the printed characters is not disturbed, and the character pattern is not deformed.
[0017]
As means for preventing the movement of the upper layer of the tube TB when the platen roller 5 is stopped, in addition to the means for braking the tube press roller 17, a brake is applied to the pinch roller 10 on the further upstream side, or an idler roller. A brake shoe (not shown) may be brought into pressure contact with the upper surface of the tube TB on the idler roller 6 from above.
[0018]
It should be noted that the present invention is not limited to the above embodiments, and various modifications are possible within the technical scope of the present invention, and it is natural that the present invention extends to those modified ones.
[0019]
【The invention's effect】
As described above, in the tube printer of the present invention, the tube press roller is disposed on the upstream side of the platen roller and close to the platen roller, and the tube is crushed by the tube press roller and the platen roller and sent to the thermal head. In addition, the contact between the thermal head and the tube is good, the printing quality is improved, and the feeding load is reduced. In addition, the brake means is provided on the tube press roller, so that the upper surface, which is fed slightly later than the lower surface due to displacement of the upper and lower surfaces of the tube during traveling, slightly moves forward due to elastic restoring force after the rotation of the platen roller stops. As a result, the character pattern printed on the upper surface can be prevented from being disturbed, and the printing quality can be improved.
[Brief description of the drawings]
FIG. 1 is a side view of a tube running system of a tube printer, showing an embodiment of the present invention.
FIG. 2 is a side view of a tube running system of a tube printer loaded with tubes.
[Explanation of symbols]
Reference Signs List 1 Chassis 5 Platen rollers 6, 7 Idler roller 10 Pinch roller 15 Arm 17 Tube press roller 18 Thermal head TB Tube

Claims (1)

In a tube printer, a thermal head is placed on a platen roller, a soft vinyl tube is sandwiched between the platen roller and the thermal head, and the thermal head prints on the tube while rotating the platen roller to run the tube. Is arranged on the upstream side of the platen roller and close to the platen roller, the tube is pressed by the tube press roller and the platen roller to feed the tube in a crushed state, and the brake for constantly braking the tube press roller Means for preventing movement of the upper surface of the tube due to displacement of the upper and lower surfaces of the tube when the rotation of the platen roller is stopped.

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