JPH0230287Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on a type band with type formed on the outer end surface, which is passed between a driving pulley and a driven pulley, and the type band is moved in one direction in relation to the rotation of the driving pulley. The present invention relates to a running device for a type band of a printer, particularly for ensuring smooth and reliable running of the type band.

Conventionally, in a band type printer, as shown in FIG. 1, for example, a drive shaft 2 is supported on a machine frame so as to be rotatable about a fixed straight line in conjunction with a motor 1.
A drive pulley 3 is fixed to the upper end, and a support shaft 5 is rotatable about a straight line substantially along the drive shaft 2, and the support shaft 5 is supported on the machine frame so that the middle part can be rotated about an axis 4 orthogonal to the straight line. A driven pulley 6 fixed at the upper end,
In order to tension the band 7, the driven pulley 6 is always connected to the drive pulley 3 by a coiled spring 8 that is engaged with the lower end of the support shaft 5 and the machine frame. However, in conventional band printers of this type, both pulleys 3 and 6 are rotated to prevent slipping between the type band 7 and both pulleys 3 and 6. , 6 are molded with rubber 9 on the outer peripheral surfaces of the pulleys 3 and 6. If the printer is not used for a long time, the band 7 is under tension between the pulleys 3 and 6, so the band of both pulleys may Since the pressure contact force is constantly applied to the contact surface with the band, the rubber 9 in the part that contacts the band is deformed due to fatigue and does not recover, and when the printer is used next time,
The band does not run smoothly, causing noise and vibration, and the band movement speed is not constant, causing the printing timing to deviate, resulting in poor printing quality. In the case where the sensor 10 for continuing the timing mark etc. on the outer circumference of the band 7 is arranged opposite to the outer circumference of the band 7, the deformed part of the rubber 9 is the sensor 1.
When facing 0, the outer peripheral surface of band 7 and sensor 1
If the distance between the sensor 10 and the tip detection part of the rubber 9 becomes too large to make detection possible, or if the sensor 10 is brought close to the outer circumferential surface of the band 7, the tip of the sensor 10 will move closer to the band 7 when the undeformed part of the rubber 9 faces the sensor 10.
This resulted in drawbacks such as engagement with the outer peripheral surface and damage.

This invention aims to eliminate the drawbacks of the above-mentioned conventional ones.

An embodiment of this invention will be described with reference to the drawings, and the same components as those in FIG. 1 described in the conventional example will be denoted by the same numbers and the explanation will be omitted.

One end of a coil spring 8 that applies an acting force to separate the driven pulley 6 from the drive pulley 3 is locked to the lower end of the support shaft 5, and the other end of the coil spring 8 is locked to the upper end.The operating arm 11 is aligned with the axis. An electromagnet 13 is rotatably supported on the machine frame at its intermediate part about an axis 12 parallel to the arm 11, and has a plunger 13a connected to the lower end of the operating arm 11. Rotate the operating arm 11 clockwise (Fig. 2) so as to pull against the force, and when the electromagnet 13 is de-energized, the type band 7 is placed between the drive pulley 3 and the driven pulley 6 with a slight tension. A stopper 14 is provided for locking the operating arm 11 at a position where the coil spring 8 is applied so that the arm 11 is held at a position where the coil spring 8 is applied. This stopper 14 can move and lock the plunger 13a along the moving direction.

It is assumed that the electromagnet 13 energizes the drive shaft of the motor 1 in connection with generation of a printing command, and deenergizes when the band 7 stops when printing is completed.

This device has the above-mentioned configuration, and when printing starts, the electromagnet 13 is energized and pulls the lower end of the working arm 11, which causes the working arm 11 to rotate clockwise and apply elastic force to the coiled spring 8. The lower end of the support shaft 5 is pulled to the right in FIG. 2 by the elastic force, and the support shaft 5 rotates counterclockwise. 3
It will be stretched between.

In connection with the completion of printing, when the type band 7 stops, the electromagnet 13 is deenergized, and the working arm 11 is rotated counterclockwise by the restoration of the coiled spring 8, and the lower end is moved to the stopper 1.
4, the support shaft 5 rotates clockwise due to the restoration of the coiled spring 8, and the driven pulley 6 and the drive pulley 3 tighten the rubber 9 to the extent that the band 7 does not fall.
The tension of the band 7 is loosened and held so as to create frictional resistance between the band 7 and the band 7. This prevents the rubber 9 from being squeezed between the band 7 and the pulleys 3 and 6 with enough force to deform it.

In addition, as shown in FIG. 3 instead of this example,
One end of the coiled spring 8 is locked to the support shaft 5, and the other end of the coiled spring 8 is locked to the plunger 13a of the electromagnet 13. When not printing, the electromagnet 13 is deenergized, the support shaft 5 is rotated clockwise, and the stopper 14 is rotated. The band 7 may be held between the pulleys 3 and 6 by engaging the support shaft 5. Further, as shown in FIG. 4, the other end of the coiled spring 8 is locked to the machine frame, and the plunger 13a of the electromagnet 13 is directly connected to the support shaft 5. When not printing, the electromagnet is energized and the support shaft 5 is may be rotated clockwise. The electromagnet 13 is actuated to rotate the support shaft 5 clockwise, such as when the motor is stopped after printing is completed, when an operation signal is generated from the operating means, or when the motor is not driven for a certain period of time after printing is completed. Good too. Further, the support shaft 5 may be horizontally moved in a direction toward and away from the drive pulley 3. Further, as the material that imparts friction, materials other than rubber may be used as long as they have similar properties.

As described above, according to this invention, in order to apply tension to the type band that is sufficient to hold the type band to both pulleys, the electric type is placed in relation to the driven pulley so as to lock the driven pulley close to the drive pulley. a means of action that acts on;
By providing an electric circuit that operates the actuating means in connection with stopping the motor, a weak tension is applied to the type band to hold it between both pulleys when not printing, thereby reducing the elasticity of the outer periphery of the pulley. This prevents the friction body (rubber) from being strongly compressed and plastically deformed over a long period of time, making the type band run smoothly and preventing noise and vibration, as well as keeping the type band running at a constant speed to stabilize printing timing. This has the effect of improving print quality.
Further, in the case where the sensor is arranged close to the drive pulley, the distance between the sensor and the type band is constant, and effects such as reliable detection and prevention of damage can be obtained.

[Brief explanation of the drawing]

Figure 1 is a front end view of a conventional band traveling mechanism.
FIG. 2 is a perspective view of the band traveling mechanism of this embodiment, and FIGS. 3 and 4 are partial perspective views of other embodiments. In the figure, 1... Motor, 3... Driving pulley, 6... Driven pulley, 7... Type band, 8
...Elastic body (wound spring), 9,9...Friction body (rubber), 13...Electromagnet constituting the action means, 14
... Stopper, FF, G, which constitutes the action means.
C...Electric circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] A drive pulley 3 supported on a machine frame so as to be rotatable about a fixed axis in conjunction with a motor that can be rotated or stopped, and about an axis substantially parallel to the rotational axis of the drive pulley. a driven pulley 6 that can be rotated, and an endless type band 7 that has type formed on its outer surface and whose inner surface is stretched between both pulleys and can be bent.
and a friction body 9, 9 which surrounds and fixes the outer peripheral surfaces of both pulleys separately, has elasticity, and has a friction coefficient that generates frictional resistance between it and the inner surface of the type band. The above-mentioned driven pulley is supported on the machine frame so as to be movable in the direction toward and away from the driving pulley so that the distance between the driven pulley and the driving pulley can be adjusted, and is also arranged in relation to the driven pulley so that the inner surface of the type band becomes a friction body. an elastic body 8 having an elastic force that moves the driven pulley in a direction away from the driving pulley so that the type band presses against both pulleys and applies tension; actuating means 1 electrically acting to lock the driven pulley close to the drive pulley in order to apply sufficient tension to the type band;
3, 12; and an electric circuit for activating the operating means in connection with stopping the motor, and reducing the pressing force against the friction body when the motor is stopped.