JPH02208082A - Apparatus for automatically adjusting head gap - Google Patents

Abstract

PURPOSE:To easily and rapidly perform adjusting work and to perform high accuracy setting by providing an adjusting means supporting an equalizer platen by an eccentric pin in a rotatable manner and connecting the equalizer platen to an equalizer arm in a manner relatively movable in the height direction of a printing surface and revolvable around the eccentric pin with the revolution of the equalizer arm and adjusting the angle of rotation of a rotary body. CONSTITUTION:For example, the gauge corresponding to a reference gap is interposed between a printing head 2 and a printing surface 12 and an adjusting lever 22 is finely revolved. In order to move the printing surface 12 in the direction of the printing head 12, said lever 22 is finely revolved in a clockwise direction. Whereupon, an eccentric pin 27 is displaced around an axial line Z with the rotation of a revolving body 25 and an equalizer platen 11 is rotated in the clockwise direction to reduce a gap G. In this case, since an equalizer arm 31 is revolved and energized in the clockwise direction by the energizing force of a spring 39, a pinch roller 35 is closely brought into contact with a slip roller 36 under predetermined pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic head gap adjustment device that automatically adjusts the gap between a print head and a platen of a printer.

[Conventional technology] FIG. 4 shows a conventional automatic adjustment device.

In the figure, 1 is a carrier holding a print head 2;
A slip roller 6 cooperates with the pinch roller 35 to supply the paper P fed from the direction of arrow Y between the print surface 12 and the print head 2.

The head gap automatic adjustment device has both rollers 36.35
The gap G between the print surface 12 and the print head 2 is automatically adjusted according to the thickness of the paper P inserted therebetween, and includes an equalizer platen 11°, an equalizer arm 31. It is composed of adjusting means 21 and the like.

The equalizer arm 31 rotatably supports the pinch roller 35 and is rotatable about a support shaft 33 fixed to the frame (9). In addition, the equalizer platen 11 has an integral shaft 1.
It is rotatably supported by a frame via 9, and a printing surface 12 is provided on the upper part.

Here, the equalizer platen 11 and the equalizer arm 31 are connected by an adjusting means 21 so that the equalizer platen 11 adjusts the gap G as the equalizer arm 31 rotates according to the thickness of the paper P.

The adjustment means 21 includes a hole 52 into which a pin 53 integrated with the equalizer platen 11 is fitted, an arcuate groove 54 into which a tap 55 is inserted, and a long hole 57 through which a slider 58 integrated with the equalizer arm 31 is slidably guided. The adjustment plate 51 is formed to include an adjustment plate 51 having a diameter. Further, the equalizer arm 31 is urged by a spring 39 to rotate clockwise about the support shaft 33. Note that 56 is a threaded knob.

Therefore, the rotational angular position of the equalizer platen 11 about the axis 19 and the spindle 3 of the equalizer arm 31 are
If the equalizer platen 11 and the equalizer arm 31 are connected by the adjustment plate 51 by tightening the threaded knob 56 screwed into the tap 55 while maintaining the rotational angle position about 3 at a predetermined position, the thick When the equalizer arm 31 rotates counterclockwise around the support shaft 33 when paper P is supplied, the equalizer platen 11 rotates counterclockwise around the shaft 19 via the adjustment plate 51 to close the gap G. Can be expanded.

[Problems to be Solved by the Invention] In the above-mentioned conventional structure, in the adjustment means 21 formed including the adjustment plate 51, the rotation angle position of the equalizer platen 11 with respect to the shaft 19 and the rotation angle of the equalizer arm 31 with respect to the support shaft 33 cannot be adjusted. By changing the relative relationship with the position, the reference value of the gap G with respect to the thickness of the paper P is initially set.

Therefore, it has the following problems.

■ When the knob 56 is loosened during initial setting, the equalizer arm 31 is biased by the spring 39 and rotates clockwise.
and equalizer arm 31 and equalizer platen 1
The connection with 1 is broken. Therefore, both rollers 35.36
In order to adjust the relationship between the gap between the two and the gap G to the standard value, it is necessary to grasp and carefully operate the equalizer grating 11 (print surface 12) and the print head 2, which requires a lot of effort and time. .

■ Even if the reference value is set in this way, when the knob 56 is tightened again, the equalizer arm 31 and the equalizer platen 11 changes, making adjustment very troublesome.

(2) Furthermore, because the adjustment plate 51, knob 56, etc. are arranged internally due to the layout and appearance of the printer, adjustment work is complicated and requires extensive disassembly of the frame and the like.

■Furthermore, since the equalizer platen 11 is rotated around the shaft 19, the printing surface 12 is rotated around the shaft 19.
This is a circular motion centered at 9. Therefore, printing surface 1
As shown in FIG. 2 of FIG. 2, non-uniformity may occur in the vertical gap G, leading to blurred printing.

Herein, the object of the present invention is to
To provide an automatic head gap adjustment device which can be easily and quickly adjusted and can make the head gap uniform.

[Means for Solving the Problems] The present invention enables the equalizer platen and the equalizer arm to be moved relative to each other in the vertical direction without breaking the connection, and the equalizer platen is held rotatably and vertically by an eccentric pin. Moreover, even if the adjusting means is released, the relative positional relationship between the equalizer platen and the equalizer arm due to the biasing force of the spring will not change inadvertently.

In other words, a rotatable equalizer arm that holds a pinch roller relative to a slip roller and is biased in one direction and a rotatable equalizer platen that has a printing surface are connected so as to be synchronously rotatable, thereby creating an equalizer according to the paper thickness. In an automatic head gap adjustment device that adjusts the gap between a print surface and a print head by rotating an equalizer platen as the arm rotates, the equalizer platen is integrated with a rotating body rotatably mounted on a frame. The equalizer platen and the equalizer arm are rotatably supported by an eccentric pin, and the equalizer platen and the equalizer arm are connected so as to be movable relative to each other in the height direction of the printing surface and to be rotatable about the eccentric pin as the equalizer arm rotates. The present invention is characterized in that an adjusting means for adjusting the rotation angle of the rotating body is provided.

[Function] In the present invention having the above configuration, when the thickness of the paper P supplied between the pinch roller and the slip roller is thicker than the reference thickness, the equalizer arm rotates counterclockwise around the equalizer arm. Then, the equalizer platen rotates counterclockwise around the eccentric pin to enlarge the gap G between the print surface and the print head. On the other hand, if the thickness of the paper P is thinner than the reference thickness, the equalizer arm rotates clockwise due to the biasing force of a spring or the like, contrary to the above, and rotates the equalizer platen clockwise. Gap G becomes smaller.

In this way, the head gap G is automatically adjusted.

Here, in order to adjust the reference value of the gap G for the paper P of the reference thickness, that is, to initialize it, the eccentric pin is rotated while the rotating body is slightly rotated by the adjusting means. Then,
The equalizer platen expands or contracts the gap G while rotating around the eccentric pin and moving relative to the equalizer arm in the height direction of the printing surface. Therefore, it is possible to provide a uniform gap G without variation in the height direction of the printing surface. In addition, even if the adjustment means is tightened or loosened, the equalizer platen is rotatably supported via a large-diameter rotating body and an eccentric pin, so the spring force that biases the equalizer arm is directly applied to the equalizer platen. Since it does not work, it can be adjusted simply, easily, stably and quickly.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

The automatic adjustment device of this embodiment is shown in FIGS. 1 to 3. Note that the same reference numerals are given to the parts that are the same as or common to the components of the conventional automatic adjustment device shown in FIG. .

In FIG. 1, the equalizer arm 31 has a support shaft 33
The pinch roller 35 is rotatably supported by the frame 9 via the pinch roller 35 , and is biased by a spring 39 in a direction in which the pinch roller 35 approaches the slip roller 36 . Also, equalizer platen 1
1 is rotatably held by an eccentric pin 27 forming a part of adjustment means 21, which will be described in detail later.

The equalizer platen 11 and the equalizer arm 31 are integrated in the rotational direction by fitting the slider 34 integrally attached to the equalizer arm 31 into the long groove 15 bored in the equalizer platen 11. Connected for relative movement. That is, the equalizer arm 31 and the equalizer platen 11 are connected to be able to rotate synchronously.

Here, the adjusting means 21 is means for adjusting the relative position between the equalizer platen 11 and the equalizer arm 31, that is, the relationship between the distance between the pinch roller 35 and the slip roller 36, and the gap G between the printing surface 12 and the print head 2. There is an adjustment lever 22, a rotating body 26. It is composed of an eccentric pin 27 and the like.

That is, as shown in FIG. 3, the adjustment lever 22 is integrally formed with a rotating body 26 at its distal end, and is provided with an elegant circular arc groove 23 at its proximal end.

As shown in FIGS. 1 and 2, the rotating body 26 is connected to the frame 9.
It is rotatably mounted on the frame 9, and an eccentric pin 27 that is offset by an eccentric amount e is integrally provided at the center 2. Also, a screw pin 2 implanted in the frame 9 is provided in the arcuate groove 23.
By tightening a fixing nut 25 which is screwed into the screw pin 24, the rotation angle of the rotating body 26 relative to the frame 9 can be fixed.

Furthermore, the axis X of the adjustment lever 22 (the axis Z of the rotating body 26
) extends substantially orthogonally to the line segment Y passing through the axis of the support shaft 33. Also, an arc? 1!23 is a circular arc locus centered on the axis Z.

Therefore, considering the case where the fixing nut 25 is loosened, the equalizer arm 31 is moved by the biasing force of the spring 39 to the first
Even if you try to rotate the rotating body 26 clockwise in the figure, the rotating body 26 cannot be rotated via the equalizer platen 11.
It cannot be rotated without changing the relative position with respect to the
Since the rotational force due to the biasing force of the equalizer arm 31 which is integrally connected to the equalizer latch 11 in the rotational direction acts approximately in the axis X direction, the arcuate groove 23 prevents the screw pin 24 from moving in the axis X direction. Therefore, even if the fixing nut 25 is loosened, both the equalizer platen 11 and the equalizer arm 31 remain stationary because no rotational force is generated about the eccentric pin 27 and the support shaft 35 due to the biasing force of the spring 39. Become. That is, even if the adjusting means 21 is released, the gap G remains in that state.

Further, 41 indicates both rollers 35 and 36 when setting the paper P.
It is a cam body that opens the gap between the equalizer arm 31 and
The equalizer arm 31 is forcibly rotated in the counterclockwise direction in FIG. 1 against the biasing force of the spring 39 by engaging with the protruding piece 37 integral with the equalizer arm 37.

In addition, in this embodiment, as shown in FIG.
1.21 are provided as a pair on the left and right, but only the right adjusting means 21 is shown in FIG. Further, from the viewpoint of the layout inside the printer and operational convenience, the adjustment means 21 on the left side has a different size and normal posture of the adjustment lever 22 from the adjustment means 21 on the right side, but other points are the same. The explanation will be omitted.

Next, the action will be explained.

(Initial setting) Even if the fixing nut 25 forming the adjustment means 21 is loosened, the equalizer platen 11 and the equalizer arm 31
is immovable.

Next, a gauge corresponding to the reference gap is interposed between the print head 2 and the print surface 12, and the adjustment lever 22 is slightly rotated. In order to move the print surface 12 in the direction of the print head 2, it is slightly rotated clockwise in FIG. Then, as the rotating body 26 rotates, the eccentric pin 27 is deviated about the axis Z to rotate the equalizer platen 11 clockwise, thereby reducing the gap G. In this case, the pinch roller 35 is configured so that the equalizer arm 31 is connected to the spring 39.
Since it is urged to rotate clockwise by the urging force of , it is brought into close contact with the slip roller 36 with a predetermined pressure.

Here, the relative positional relationship between the rest of the equalizer arm 31 and the rotation of the equalizer platen 11 about the eccentric pin 27 is permitted by the movement of the long groove 15 and the slider 34 in the vertical direction in FIG. .

After adjusting the gap G to the reference value in this way, the fixing nut 25 is tightened to fix the adjustment lever 22 to the screw pin 24 integrated with the frame 9.

In this case, the pressing force applied to the adjustment lever 22 in the direction of the axis X based on the urging force of the spring 39 is received by the arcuate groove 23, so that the gap G does not change.

(Paper setting) The equalizer arm 31 is rotated counterclockwise by rotating the cam body 41 and pushing the protrusion 37 downward in FIG. 1, thereby enlarging the gap between the inner rollers 35 and 36.

When the cam body 41 is returned to its original position, due to the biasing force of the spring 39,
Both rollers 35 and 36 feed the set paper P into the gear gear G while nipping it.

(Printing) In this way, when the cam body 41 is returned to its original position, the pinch roller 35, that is, the equalizer arm 31 has detected the thickness of the paper P.

Therefore, the equalizer platen 11 connected to the equalizer arm 31 rotates around the eccentric pin 27 accordingly, and automatically adjusts the gap G according to the thickness of the paper P.

As a result, clear printing can be achieved with a uniform gap G.

According to this embodiment, the equalizer platen 11 is rotatably supported by the eccentric pin 27 integrated with the rotating body 26 rotatably mounted on the frame 9, and the equalizer platen 11 and the equalizer arm 31 are printed. An adjusting means 21 that is movable relative to the height of the surface 12 and rotatably connected to the eccentric pin 27 as the equalizer arm 31 rotates, and adjusts the gap G by adjusting the rotation angle of the rotating body 26. Since the rotating body 26 cannot be rotated by the biasing force of the equalizer arm 31, the relative positional relationship between the equalizer platen 11 and the equalizer arm 31 remains unchanged even if the adjusting means 21 is released. In other words, the gap G is constant. Therefore, the gap G can be adjusted quickly and easily without requiring the conventional excessive labor and time of carefully adjusting the equalizer platen 11 (print surface 12) and print head 2 while holding them.

Further, for the same reason, the gap G does not change even when the fixing nut 25 is operated to fix the adjusting means 21, so that the gap G can be maintained at an optimal and highly accurate level.

Further, the adjustment means 21 includes a rotating body 2 that is integrated with the faith pin 27.
6 is slightly rotated by a long adjustment lever 22, so for active adjustment operation, the load is light and easy to operate due to the lever principle. It can be easily and safely adjusted without having to insert your hand into the

Furthermore, the equalizer platen 11 and the equalizer arm 31 are connected so as to be movable relative to each other in the height direction of the printing surface 12 so as to allow two-dimensional movement of the steel core pin 27. Variations due to arcuate movement of the printing surface 12 do not occur, a uniform gap G can be established, and clear printing can be guaranteed.

Furthermore, if the direction of rotation of the adjustment lever 22 is changed depending on the direction of decreasing or increasing the reference gap G, and the position of the eccentric pin 27 is set at the neutral position, for example, the highest position in the reference gap G. , the arc error can be further reduced.

[Effect of the Invention 1] As is clear from the above description, the present invention rotatably supports the equalizer platen on an eccentric pin integrated with a rotating body rotatably attached to the frame, and also connects the equalizer platen and the equalizer arm. This is because it is configured to be relatively movable in the height direction of the printing surface and connected to be rotatable about the eccentric pin as the equalizer arm rotates, and provided with an adjusting means for adjusting the rotation angle of the rotary body. It has the following effects.

■ The head gap does not change when adjusting or fixing, so
Adjustment work can be done easily and quickly, and high-precision settings can be made.

- Since the equalizer platen is rotatably supported by a steel core pin that deviates in two dimensions, it is possible to establish a uniform gap with small circular motion errors.

■ The rotation of the rotating body is adjusted by an adjustment lever, and the adjustment lever can be placed outside the internal equipment, so the gap can be adjusted easily and safely.

■ Since the adjustment lever can be formed from a plate member, the installation space is small, making it possible to downsize the entire printer and expand its layout flexibility.

■ What is the equalizer platen and equalizer arm?
Since the long lever and the slider are connected by fitting together with a pin or the like, the structure is simple and the operation is stable.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
Figure 3 is a front view seen from the arrow line ■-■ side in the figure, Figure 3 is a bottom view of the adjustment lever with a part omitted as seen from the arrow line 1-11 in Figure 1, and Figure 4 is a conventional automatic It is a side view showing an adjustment device. 2... Print head, 9... Frame, 11... Equalizer platen, 12... Print surface, 15... Long explanation, 21... Adjustment means, 22... Adjustment lever 23... - Arc spring, 25... Fixed nut, 26... Rotating body, 27... Eccentric pin, 31... Equalizer arm, 33... Support shaft, 34... Slider, 35... Pinch roller, 36...Slip roller. Figure Figure Figure Figure

Claims (1)

[Claims] (1) A rotatable and unidirectionally biased equalizer arm holding a pinch roller relative to a slip roller and a rotatable equalizer platen having a printing surface are connected for synchronous rotation, and the In an automatic head gap adjustment device that adjusts the gap between a print surface and a print head by rotating an equalizer platen in conjunction with rotation of an equalizer arm, the equalizer platen is a rotating body rotatably mounted on a frame. The equalizer platen and the equalizer arm are rotatably supported by an integrated eccentric pin, and the equalizer platen and the equalizer arm are movable relative to each other in the height direction of the printing surface and can be rotated about the eccentric pin as the equalizer arm rotates. 1. An automatic head gap adjustment device, characterized in that an adjustment means is connected to the rotary body and adjusts the rotation angle of the rotary body.