JPH02235779A - Bail roller opening/closing mechanism for printer - Google Patents

Abstract

PURPOSE:To automatically open or close a bail roller without influence to a loading operation of a sheet even if an exclusive use motor is not provided by providing a driving mechanism for driving to open or close the roller by a driving force of a space motor, and an engaging/disengaging mechanism for engaging or disengaging power in the driving mechanism. CONSTITUTION:In a printer having a space motor 6 for moving a print head 1 along d platen 2, and a bail roller 4 for retaining a printing medium on the platen 2, a driving mechanism 7 for driving to open or close the roller 4 by the driving force of the motor 6, and an engaging/disengaging mechanism 8 for engaging or disengaging power in the mechanism 7 are provided. That is, since the head 1 is not printed during a sheet loading operation, even if the motor 6 is operated during the period, it does not affect the influence of the printing. Then, the motor 6 is used as a drive source to drive the roller 4 to automatically open or close the roller 4 without providing an exclusive use motor without influence to the loading operation, etc.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Conventional Technology (Figures 17 and 18) Means for Solving the Problems to be Solved by the Invention (Figure 1) Working Examples (Al Explanation of the first embodiment (Figs. 2 to 7) (b) Explanation of the second to eighth embodiments (Figs. 8 to 14) (Cl Description of the ninth embodiment ( Figure 15, Figure 16) (d
) Description of other embodiments Effects of the invention [Summary] Regarding the bail roller opening/closing mechanism of a printer for automatically opening/closing the bail roller that holds the print medium on the platen, the present invention relates to a bail roller opening/closing mechanism of a printer that does not affect the paper loading operation without providing a dedicated motor. A platen, a print head that moves along the platen and performs printing, and a space motor that moves the print head along the platen. A printer having a bail roller that presses a print medium on the platen is provided with a drive mechanism for opening and closing the bail roller using the driving force of the space motor, and a connecting/disconnecting mechanism for connecting/disconnecting power in the driving mechanism. Ta.

[Industrial application field]

The present invention relates to a bail roller opening/closing mechanism for a printer that automatically opens and closes a bail roller that presses a print medium on a platen.

Printers can print continuous forms and cut sheets.
A bail roller is provided to press the paper against the platen near the print head to ensure a good printing operation.

In recent years, with the automatic loading of paper, mechanisms for automatically opening and closing bail rollers have been provided, and there is a need for technology that can automatically open and close bail rollers with a simple mechanism.

[Conventional technology]

FIG. 17 is an explanatory diagram of the printer.

In the printer shown in FIG. 17, an opening 3a of a cover 3, which is a paper discharge port, is provided above the platen 2, and a printing head 1 is provided on the left side.

The print head 1 moves spacing along the platen 2 and prints on a cut sheet SP inserted from a guide 5a or a continuous paper LP fed by a tractor 5b.

A bail roller 4 for holding down the paper is provided between the print head 1 and the cover 3 at the top.
direction and discharged from the opening 3a.

If the bail roller 4 is equipped with an automatic opening/closing mechanism, the bail roller 4
opens, and after loading the paper, the bail roller 4 operates to close.

FIG. 18 is an explanatory diagram of the prior art.

The one shown in FIG. 18 opens and closes the bail roller 4 using the rotational movement of an LF (line feed; paper feed) motor.

That is, the gear 50a on the rotating shaft of the LF motor 50 is transmitted to a pair of gears G1 and G2, and the gear G2 is transmitted to the gears G4 and G5 at the end of the pale arm 4b by a planetary gear G3 operated by magneto.

Gears G4 and G5 are provided with teeth on only some of them so that they are on opposite sides of each other, and when the teeth of either of these gears G4 and G5 mesh with the teeth carved at the end of the pale arm 4b, the pale arm 4b Rotate the Pale Arm 4
The bail roller 4 provided on the support shaft 4a of b is opened/closed.

In the illustrated example, when the LF motor 50 rotates in the direction of the arrow, the bail arm 4b is rotated in the opening direction of the bail roller 4 by the gear G5.

After that, when the planetary gear G3 is operated by the magnet again to transmit power, the gear G4 rotates the bail arm 4b in the closing direction of the bail roller 4.

In addition, as another conventional technology, the oven/
A closing motor is provided, and the rotational motion of this motor is transmitted to a cam via several gears, and the movement of this cam swings the bail arm 4b, opening/closing the bail roller 4 that is continuous with the bail arm 4b. It is something.

[Problem to be solved by the invention]

However, when the LF motor is used as a drive source for automatically opening and closing the bail roller, the bail roller is driven to open and close while the LF motor is loading paper. There was a problem in that the load on the paper fluctuated, and paper line feed misalignment occurred during the loading operation.

Furthermore, when a dedicated motor is provided, there is a problem in that the cost increases accordingly.

Therefore, the present invention provides a bail roller opening/closing m for a printer that can automatically open/close the bail roller without having to provide a dedicated motor and without affecting the paper loading operation.
[Means for Solving the Problem] FIG. 1 is a diagram showing the principle of the present invention.

The present invention, as shown in FIG. In a printer having a space motor 6 and a bail roller 4 that presses a print medium on the platen 2, a drive mechanism 7 for opening and closing the bail roller 4 by the driving force of the space motor 6; A connecting/disconnecting mechanism 8 for connecting/disconnecting power is provided.

[Effect]

Since no printing is performed by the printing head 1 during the sheet loading operation, even if the space motor 6 is operated during this period, the printing operation is not affected.

Therefore, the present invention uses the space motor 6 as a driving source,
By driving the bail roller 4, it is possible to automatically open and close the bail roller 4 without affecting the loading operation or the like and without providing a dedicated motor.

C Embodiment] (al Explanation of the first embodiment FIG. 2 is a configuration diagram of the first embodiment of the present invention, FIG. 3 is a sectional view of the first embodiment of the present invention, and FIG. 4 is a diagram of the first embodiment of the present invention. FIG. 1 is an overall diagram of a first embodiment.

Note that FIG. 3(B) is a sectional view taken in the direction A of FIG. 3(A), and FIG. 3(C) is a sectional view taken in the direction B of FIG. 3(A).

A pulley 6la is provided on the shaft 60 of the space motor 6, and a timing helt 62 is stretched between the pulley 612 and the other pulley 6lb, as shown in FIG.

A carriage 10 carrying the print head 1 is connected to the timing belt 62, and the carriage 10 and the print head 1 are spaced and moved along the platen 2 along a pair of guides 10 and 11.

The shaft 60 of the space motor 6 is further supported by a bearing 63 on a bracket 70, and a bevel gear 64 is provided at the tip thereof.

The bracket 70 has a rotating shaft 71a, as shown in FIG. 3(A).
, (B), the bevel gear 7 that engages with the bevel gear 64
1 is provided, and a rotating arm (crank) 72 is further provided connected to this. The rotary arm 72 has a bail roller 4 at its tip, and is connected by a loft 73 to a bail arm 4b that rotates around a fulcrum 40.

The bracket 70 also includes a thalassotile lever 81 that rotates around a fulcrum 8lb, an electromagnetic magnet 80 that drives the clutch lever 81, a coil spring 82 that applies a return force to the clutch lever 81, and a bevel gear 71 that is connected to the clutch lever 81. A pressing member 83 is provided for slidingly moving the.

The tip 81a of the clutch lever 81 has an oblique cross section as shown in FIG. 3(C), and the electromagnetic magnet 80
3A and 3C, and enters between the bracket 70 and the pressing member 83,
By moving the pressing member 83 to the right in FIG. 3(C), the bevel gear 71 is shifted to the right in FIG. 3(C) and engaged with the bevel gear 64 of the space motor 6.

5 and 6 are explanatory diagrams of the operation of the first embodiment of the present invention,
FIG. 7 is a time chart diagram of the first embodiment of the present invention.

■ Under normal conditions, as shown in Figure 4, Magnesoto 80
is off, and bevel gear 71 and bevel gear 64 are not engaged.

Further, the space motor 6 is not rotating either, and the bail roller 4 is in a closed state.

■ In this state, when paper is loaded, as shown in FIG. It meshes with the gear 64.

At this time, the tip 81a of the clutch lever 81 is
As shown in C), since the bevel gear 71 is shifted via the pressing member 83, the bevel gear 71 is not shifted diagonally by the tip 81a of the clutch lever 81, but is shifted horizontally.

Then, the space motor 6 rotates in the opposite direction for a certain period of time.

Therefore, as shown in FIG. 5(A), due to the reverse rotation of the space motor 6, the rotating arm 7 is rotated through the bevel gears 64 and 71.
2 rotates, the bail arm 4b is rotated via the loft 73, and the bail roller 4 is brought into an open state.

(2) Then, when the rotation of the space motor 6 is turned off and the magnet 80 is turned off, the meshing between the bevel gears 71 and 64 is released as shown in FIG. 5(B), and the bail roller 4 maintains the oven state.

When the bail roller 4 is opened, sheets are loaded as shown in FIG.

■ When the paper loading is completed, the magneto-soto 80 is turned on again as shown in Fig. 6, and the crassochi lever 81 is turned on again.
After meshing the bevel gears 71 and 64,
Rotate the space motor 6 in the forward direction.

Therefore, as shown in FIG. 6, the forward rotation of the space motor 6 rotates the rotary arm 72 via the bevel gears 64 and 71, rotates the bail arm 4b via the rotor 73, and closes the bail roller 4.

Then, as shown in FIG. 7, the forward rotation of the space motor 6 is turned off, the magnet 80 is turned off, the meshing of the bevel gears 64 and 71 is released, and the state shown in FIG. 4 is returned to open/close. The operation is finished and printing starts.

During this time, the space motor 6 moves the printing head 1 left and right along the platen 2, but this is not a problem since printing has not yet started.

Further, from then on, the electromagnetic magnet 80 is not turned on, and the power of the space motor 6 is not transmitted to the drive mechanism 7 of the bail roller 4, but is cut off.
Even if the spacing is moved, the bail roller 4 does not open or close.

In this way, the bail roller 4 can be opened/closed by using the space motor 6 as a drive source and connecting/disconnecting the power transmission of the drive mechanism 7 with the connecting/disconnecting mechanism 8 (magnet 80 or the like).

(bl Description of Second to Eighth Embodiments FIG. 8 is a block diagram of a second embodiment of the present invention.

In the figures, the same parts as those shown in FIGS. 1 to 6 are indicated by the same symbols.

In this embodiment, a belt is used in contrast to the first embodiment, which uses a rotary arm 72 and a rod 73 to convert rotational motion into swinging motion.

That is, a booley 742 is provided on the shaft 71a of the bevel gear 71 instead of the rotary arm 72, and a booley 74b is provided on the shaft 40 of the pale arm 4b, so that both boogies 74
A belt 74c is provided between 3 and 74b.

Other parts such as the connecting/disconnecting mechanism 8 using the magnet 80 and the bevel gear 71 of the drive mechanism 7 are the same as in the first embodiment, and their operations are the same as in FIG. 7.

FIG. 9 is a configuration diagram of a third embodiment of the present invention.

In the figure, the same parts as shown in Figures 1 to 6 are:
They are indicated by the same symbols.

In this embodiment, gears are used to convert rotational motion into swinging motion of the hail arm 4b.

That is, a gear 75a is provided on the shaft 71a of the bevel gear 71, a gear 75g is provided on the shaft 40 of the pale arm 4b, and the gears are connected by transmission gears 75b to 75f.

FIG. 10 is a block diagram of a fourth embodiment of the present invention.

In the figure, the same parts as shown in Figures 1 to 6 are:
They are indicated by the same symbols.

In this embodiment, a compound cam is used to convert rotational motion into swinging motion of the pale arm 4b.

That is, a gear 76a is provided on the shaft 71a of the bevel gear 71, a gear 76i is provided on the shaft 40 of the hail arm 4b, and the power of the gear 76b is transmitted to the cam 76d by the gears 76b and 76c.

An L-shaped lever 76e is engaged with the cam 76d.
The L-shaped lever 76e is rotated by the cam 76d, and the rotation of the L-shaped lever 76e is transmitted to the gear 76i by the gears 76f to 76h, thereby rotating the pale arm 4b.

FIG. 11 is a configuration diagram of a fifth embodiment of the present invention.

In the figure, the same parts as shown in Figures 1 to 6 are:
They are indicated by the same symbols.

In this embodiment, a plate cam is used to convert rotational motion into swinging motion of the hail arm 4b. 7e is used.

That is, a gear 77a is provided on the shaft 71a of the bevel gear 71, and the plate cam 77e is rotated through the gears 77b, 77C, and 77d.

The plate cam 77e has an L biased by a tension spring 77g.
The L-shaped lever 77f is engaged, and the gear 77h provided on the shaft of the L-shaped lever 77f meshes with the gear 77i provided on the shaft 40 of the pale arm 4b.

Therefore, by rotating the L-shaped lever 77f, which is biased clockwise by the pull bus 77g, counterclockwise by the plate cam 77d, the pale arm 4b is rotated in the closing direction of the arrow.

FIG. 12 is a configuration diagram of a sixth embodiment of the present invention.

In the figure, the same parts as shown in Figures 1 to 6 are:
They are indicated by the same symbols.

In this embodiment, a swinging slider crank mechanism is used to convert rotational motion into plating motion of the pale arm 4b.

That is, a rotary plate (crank) 78a provided with an engagement pin 780 is provided on the shaft 71a of the bevel gear 71, and the fulcrum 7
Slide the slider 78b, which swings around 82, into the slide hole 7.
81 is engaged with the engagement pin 780, and the tip thereof is attached to the rear end of the pale arm 4b.

In this embodiment, by rotating the space motor 6 in one direction,
Pail arm 4b opens/closes.

FIG. 13 is a configuration diagram of a seventh embodiment of the present invention.

In the figure, the same parts as shown in Figures 1 to 6 are:
They are indicated by the same symbols.

In this embodiment, a rank 78d and a pinion 78c are used to convert rotational motion into swinging motion of the pale arm 4b.

That is, a pinion gear 78c is provided on the shaft 71a of the bevel gear 71, and a rank 78d whose tip is engaged with the pale arm 4b is provided.

FIG. 14 is a configuration diagram of an eighth embodiment of the present invention.

In this embodiment, instead of using a bevel gear mechanism to transmit power, a worm gear mechanism is used.

That is, the shaft 60 of the space motor 6 is provided with a spur gear 79a that is slidable in the axial direction, and the clutch lever 83 of the connection/disconnection mechanism 8 is configured to slide the spur gear 79a around a fulcrum 83a.

Further, a worm gear 79b is provided on the spur gear 79a, a boolean J-79c is provided coaxially with the worm gear 79b, and a bell 79d is used to connect the boule 79e provided on the shaft 40 of the pale arm 4b.

In this example, the clutch lever 8 is driven by the magnet 80.
3, the spur gear 79a is shifted and the worm gear 79
Break the engagement with b.

When the worm gear 79b and the spur gear 79a are in mesh with each other, the driving force of the space motor 6 is applied to the pulleys 79c,
It is transmitted to the pulley +J-79e via the belt 79d, and swings the pale arm 4b.

(Cl Description of Ninth Embodiment FIGS. 15 and 16 are configuration diagrams of the ninth embodiment of the present invention, FIG. 15(A) is a side view, and FIG. 15(B) is an exploded configuration thereof. 16A and 16B are cross-sectional views thereof.

In this embodiment, in addition to the configuration of the first embodiment, a torque limiter (power transmission limiting mechanism) is provided between the bevel gear 71 and the rotating arm (crank) 72.

That is, the bevel gear 71 is provided with a convex portion 7lb, and the crank 72
A recess 72b is provided correspondingly.

As shown in FIG. 16, the convex portion 7lb of the bevel gear 71 has a large number (eight in the figure) of triangular protrusions around its periphery.

On the other hand, the concave portion 72b of the crank 2 is provided with a large number of protrusions 72a (seven in the figure) as shown in FIG.

Then, as shown in FIG. 16(A), a temporary spring 71c having a shape that does not have an approximately U-shape and engages with a triangular protrusion of the protrusion 7lb of the bevel gear 71 is attached to the protrusion 7l of the bevel gear 71.
b and the recess 72a of the crank 72 in FIG. 16(A).
Insert it like this.

Therefore, under normal conditions, the triangular protrusion 7 of the bevel gear 71
lb and the leaf spring 71C are engaged, and this is the crank 7.
2 and transmits power.

On the other hand, if an overload is applied to the crank 72 side, as shown in FIG.
), the leaf spring 71C deforms and comes off the triangular protrusion 7lb of the bevel gear 71, causing the bevel gear 71 to idle,
Power transmission is cut off.

The significance of providing such a torque limiter is as follows.

First, the bail roller 4 is a workpiece that is touched by the operator, and the operator may touch the bail roller during the automatic opening/closing operation of the bail roller, and an overload may be applied to the power transmission system.

Further, when the cassette sheet feeder is installed in the printer, a part of the cover of the cassette sheet feeder may interfere with the bail shaft, causing an overload on the bail roller.

Further, if the amount of control when closing the bail roller is too large, the paper will be pressed too much and impressions will be left on the copy paper.

For this reason, a torque limiter is provided to prevent damage to the mechanism and impressions on the copy paper by cutting off power transmission when an overload is applied during automatic opening and closing of the bail roller.

In this embodiment, the torque limiter can be realized with a simple configuration using the temporary spring 71c.

fdl Description of other embodiments Although the drive mechanism 7 has been explained in each embodiment, it is not limited to this.
Further, the connecting/disconnecting mechanism 8 is not limited to the embodiment.

Furthermore, the torque limiter may be applied to the second to eighth embodiments, and the torque limiter is not limited to that of the ninth embodiment.

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention, and these are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, the bail roller is automatically opened and closed using the space motor as the drive source, so the bail roller can be automatically opened and closed without adversely affecting the paper loading operation and without providing a dedicated motor. This has the effect that the bail roller can be automatically opened and closed stably and at low cost.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is a configuration diagram of a first embodiment of the invention, Fig. 3 is a sectional view of the first embodiment of the invention, and Fig. 4 is a diagram of the first embodiment of the invention. 5 and 6 are operation explanatory diagrams of the first embodiment of the present invention. FIG. 7 is a time chart of the first embodiment of the present invention. FIG. 8 is a diagram of the second embodiment of the present invention. Embodiment configuration diagram, FIG. 9 is a configuration diagram of a third embodiment of the present invention, FIG. 10 is a configuration diagram of a fourth embodiment of the present invention, FIG. 11 is a configuration diagram of a fifth embodiment of the present invention, 12 is a block diagram of a sixth embodiment of the present invention, FIG. 13 is a block diagram of a seventh embodiment of the present invention, FIG. 14 is a block diagram of an eighth embodiment of the present invention, and FIGS. FIG. 16 is a configuration diagram of a ninth embodiment of the present invention, FIG. 17 is an explanatory diagram of a printer, and FIG. 18 is an explanatory diagram of a conventional technique. In the figure, 1 - print head, 2 - platen, 4 - bail roller, 6 - space motor, 7 - drive mechanism, - connecting/disconnecting mechanism.

Claims (1)

[Claims] A platen (2), a print head (1) that moves along the platen (2) and performs printing, and moves the print head (1) along the platen (2). In a printer having a space motor (6) for holding a print medium on the platen (2), and a bail roller (4) for holding a print medium on the platen (2), the bail roller (4) is driven to open and close by the driving force of the space motor (6). a drive mechanism (7); and a connection/disconnection mechanism (
8) A bail roller opening/closing mechanism for a printer, characterized by comprising: