JPH074928Y2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a printing apparatus provided with a feed roller that is rotated to feed a printing sheet.

(Prior Art) Conventionally, in order to supply a print sheet toward a sheet support arranged along a print line of a printing device, a feed roller is rotatably disposed on a sheet feed side of the sheet support, and It is known that a press roller is provided that is rotated while following the feed roller while pressing the print sheet against the feed roller.

(Problems to be solved by the invention) However, in this conventional configuration, the pressing roller is supported by the main body of the apparatus through the swing arm, and the pressing position of the pressing roller is engaged with the feed roller by the urging force of the spring, and Since it is arranged so that it can be switched to the release position that is separated from the feed roller against the force, not only the number of parts increases and the assembly becomes troublesome, but the installation space for the presser roller increases. Then, there is a problem that the compactness of the entire device is hindered.

(Object of the Invention) The present invention has been made in order to solve the above-mentioned problems, and the object thereof is to reduce the number of parts and to easily assemble and to make the entire apparatus compact. An object of the present invention is to provide a printing device capable of performing the above.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a slide groove provided in a frame near the feed roller and having an opening at the top and a bottom portion of the slide groove are passed. And a cam shaft having a cam surface that is rotatably disposed on the slide shaft and that is displaced in accordance with the rotation, and is slidably mounted in the slide groove through the opening, and a lower portion of the cam shaft contacts the cam surface of the cam shaft. And a bearing body in the upper part, which can move up and down by the displacement of the cam surface, and a shaft supported by the bearing portion, which comes into contact with and separates from the feed roller as the bearing body moves up and down. A pressing roller is provided.

(Operation) Therefore, according to this invention, the bearing body is moved up and down by the displacement of the cam surface caused by the rotation of the cam shaft, and the pressing roller is brought into contact with and separated from the feed roller by the up and down movement.

(Embodiment) An embodiment of a printing apparatus embodying the present invention will be described in detail below with reference to the drawings.

Side walls 2 and 3 are provided upright on both left and right sides of a lower frame 1 of the printer. A platen frame 4 is installed between the upper portions of both side walls 2 and 3, and a rod-shaped platen 5 is mounted on the front surface thereof. The thermal transfer type print head 6 is movably arranged along the platen 5, and prints on a print sheet supplied to the front surface of the platen 5 via an ink ribbon (not shown).

Below the platen frame 4, a feed shaft 7 is rotatably supported between the side walls 2 and 3, and a plurality of feed rollers 8 are integrally rotatably inserted on the feed shaft 7 at predetermined intervals. It is supported. A spring 10 is wound around the feed shaft 7 between a retaining ring 9 mounted near the left end of the feed shaft 7 and the inner surface of the left side wall 2, and the urging force of the spring 10 causes a protrusion 11 at the right end of the feed shaft 7. Is engaged with the right standing piece 1 a of the lower frame 1.

A guide frame 12 is arranged on the lower outer periphery of the feed roller 8, and a plurality of positioning pieces 12a protruding from the lower surface of the guide frame 12 penetrate the lower frame 1. Guide frame 12
The upper surface of the platen has a substantially arcuate cross section, and the platen 5
A paper guide passage 13 is formed toward the sheet. Housing portions 14 and 15 are formed in the guide frame 12 on the front and rear sides of each of the feed rollers 8. Rear accommodations 14
The rear side presser roller 16 made of sponge rubber
Is movably accommodated between a lower release position which is separated from the feed roller 8 as shown by the solid line in FIG. 1 and an upper use position which is pressed against the feed roller 8 as shown by the chain double-dashed line in FIG. Has been done.

Supporting pieces 17 are provided on the lower surface of the guide frame 12 so as to protrude below the pressing shaft 16a common to the rear pressing rollers 16 and to correspond to both sides of the rear pressing rollers 16. Each support piece 17 is formed with slide grooves 17a having openings on both sides and an upper portion,
A cam shaft 18 having an oval cross section is inserted and supported at the bottom of each slide groove 17a. On the outer peripheral surface of the cam shaft 18, a planar cam surface 18a and an arcuate cam surface 18b that are displaced along with the rotation thereof are provided.
Are formed.

In each support piece 17, a block-shaped bearing body 19 is inserted from an upper opening and supported so as to be vertically movable, and the rear side pressing roller 16 is provided on a bearing portion 19a formed in the upper portion and having a semicircular cross section. The pressing shaft 16a of is engaged. And the camshaft 18
With the rotation of, each bearing member 19 is moved up and down through the engagement between each cam surface 18a, 18b and the lower portion of each bearing member 19, and accordingly, each rear pressing roller 16 is moved to the lower release position and It is moved up and down all at once between the upper use positions.

Bearing recesses 20 extending in the radial direction of the feed roller 8 are formed on the opposing walls of the front housing portions 15, respectively.
The front side pressing roller 21 can be rotated by the shaft pieces 21a on both sides thereof, and the front release position shown by the solid line in FIG.
It is movably supported with respect to the rear use position shown by the dotted line. Then, when the front side pressing roller 21 is arranged at the front release position, it is separated from the feed roller 8, and when it is arranged at the rear use position, it comes into contact with the feed roller 8. A shaft support 22 is attached to the lower surface of the lower frame 1 below each front housing portion 15. A shaft support piece 22a corresponding to each front side pressing roller 21 is integrally bent and formed on the shaft support body 22, and an operating shaft 28 is rotated between each shaft support piece 22a, the positioning piece 12a and the lower frame 1. It is inserted and supported as much as possible. A spring receiving recess 24 corresponding to each front pressing roller 21 is formed on the outer periphery of the operating shaft 23.

Between the actuating shaft 23 and each front pressing roller 21, a leaf spring 25 having a side surface and an approximately L shape is disposed. The base end portion of the lower bent piece 25a of the leaf spring 25 is arranged in the spring receiving recess 24, and the entire lower bent piece 25a is arranged so as to be able to contact the lower surface of the lower frame 1 and The central portion of the bent piece 25a is inserted into the positioning piece 12a. Further, the leaf spring 25 is provided with a pair of upper bent pieces 25b extending in a substantially vertical direction so as to be orthogonal to the radial direction of the feed roller 8, and each upper bent piece 25b is a shaft piece 21a of the front side pressing roller 21. Are abutted against each other.

When the spring receiving recess 24 of the actuating shaft 23 is located at the position shown in FIG. 1, the leaf spring 25 is located at the pressing force releasing position shown in FIG. 1, and the shaft piece 21a of the pressing roller 21 is the bearing. Recess 2
It is separated from the feed roller 8 by being engaged with the upper bent piece 25b of the leaf spring 25 in the vicinity of the 0 front opening.
Further, the operating shaft 23 is rotated by a predetermined angle so that the spring receiving recess is formed.
In the state where 24 is arranged at the position shown in FIG. 2, the leaf spring 25
Is arranged at the pressing force generating position shown in the figure, and the lower bent piece 25a thereof is pressed against the lower surface of the lower frame 1, and
By displacing the upper bent piece 25b toward the feed roller 8, each front pressing roller 21 is moved from the front release position to the rear use position and pressed by the feed roller 8.

A drawer shaft 26 extending parallel to the feed shaft 7 is rotatably supported between the left and right side walls 2 and 3 above the platen 5, and a plurality of drawer rollers 27 are arranged on the drawer shaft 26 at predetermined intervals. It is inserted and supported so as to be integrally rotatable.
A spring 29 is wound around the drawer shaft 26 between a retaining ring 28 mounted near the left end of the drawer shaft 26 and the inner surface of the left side wall 2.
Due to the biasing force of the spring 29, the protrusion 30 at the right end of the drawer shaft 26
Is engaged with the right standing piece 1 a of the lower frame 1.

Further, in front of the pull-out roller 27, a pressing roller 31 which rotates following the pull-out roller 27 is arranged.

On the other hand, a paper roll-in prevention member 32 is attached to the platen frame 4 so as to be located between the feed rollers 8. Each entrainment prevention member 32 extends along the paper guide passage 13 at a position spaced apart from the paper guide passage 13 of the guide frame 12 by a predetermined distance, and each feed roller 8
An entrainment prevention portion 32a is formed which is located closer to the feed shaft 7 than the outer circumference of the. The rear upper end of the roll-in prevention portion 32a is locked to the inner side surface of the platen frame 4, and the front upper end extends to near the lower portion of the platen 5. This entanglement prevention unit 32
Substantially U-shaped mounting pieces 32b are provided on both sides of a, and locking protrusions 32c formed on the upper ends of the mounting pieces 32b are fitted and fixed in the mounting holes 4a of the platen frame 4, whereby the respective roll-in prevention members 32 are secured. It is suspended and supported by the platen frame 4.

Now, when the printing paper is mounted on the printing apparatus in this embodiment, the cam shaft 18 is arranged at the rotation angle position shown by the solid line in FIG. 3, and the engagement between the planar cam surface 18a and the bearing body 19 is set. The bearing body 19 is arranged at the lower position through the gap, and the rear pressing roller 16 is arranged at the release position shown by the solid line in the figure. Further, the operating shaft 23 is arranged at the rotation angle position shown in FIG. 1, the leaf spring 25 on the operating shaft 23 is held in an unloaded state, and the upper bent piece 25b of the leaf spring 25 and the shaft piece 21a are connected to each other. The engagement of each front side pressing roller 21 is arranged at the release position shown by the solid line in FIG.

In this state, after inserting the printing paper toward the platen 5 from between the rear side press roller 16 and the feed roller 8 and arranging the leading end between the front side press roller 21 and the feed roller 8,
When a paper release lever (not shown) is operated, both shafts 1 are moved through a motion transmission mechanism (not shown) arranged between the paper release lever and the cam shaft 18 and the operating shaft 23.
8,23 are synchronously rotated over a predetermined angle.

As the cam shaft 18 rotates, the arcuate cam surface 18b
The bearing body 19 is lifted by the engagement with and the rear pressing roller 16 is pressed against the feed roller 8 accordingly. Further, the leaf spring 25 is moved from the position shown in FIG. 1 to the position shown in FIG.
Is brought into close contact with the lower surface of the lower frame 1, and the upper bending piece 25b is displaced toward the feed roller 8 side against the elasticity of itself, and the front bending roller 21 is pressed against the feeding roller 8 by the upper bending piece 25b. To be done. Therefore, the print sheet is pressed against the feed roller 8 by the both pressing rollers 16 and 21.

When the drive motor 33 shown in FIG. 1 is driven in this state,
Along with the rotation, the shafts 7 and 26 are rotationally driven in the paper feed direction through a gear transmission mechanism (not shown) including driven gears 34 and 35 on the shafts 7 and 26, and are integrated with the feed shaft 7. Then, each feed roller 8 is rotated, and the pressing rollers 16 and 21 are rotated following the feed roller 8.

As the rollers 8, 16 and 21 rotate, the print paper is transported through the paper guide passage 13 toward the platen 5, and a predetermined character is printed by the print head 6 which is operated in connection with the paper transport operation. Is printed on the printing paper. Then, the print sheet that has passed the front surface of the platen 5 is inserted between the pull-out roller 27 and the pressing roller 31, and is pulled out of the printer by the rotation of the pull-out roller 27.

Further, when the printing paper located on the paper guide passage 13 is discharged at the end of the printing operation, when the paper release lever (not shown) is operated in the release direction, the cam shaft 18
And the operating shaft 23 is synchronously rotated back. That is, the camshaft
When 18 is moved back from the two-dot chain line position in FIG. 3 to the solid line position, its arcuate cam surface 18b is separated from the bearing body 19, and the planar cam surface 18a faces the bearing body 19, The body 19 and the rear side press roller 16 are lowered by their own weight, and the rear side press roller 16 is returned to the release position shown in FIG.

When the actuating shaft 23 is returned from the position shown in FIG. 2 to the position shown in FIG. 1 so that its spring receiving recess 24 faces the lower bent piece 25a of the leaf spring 25, the leaf spring 25 2 is lowered from the position shown in FIG. 2 to the position shown in FIG. 1, the pressing force on the front side press roller 21 by the upper bending piece 25b is released, and the front side press roller 21 moves to the first position along the bearing recess 20. It is moved back to the release position shown in the figure.

Next, the knob 7a (see FIG. 4) provided at the left end of the feed shaft 7 is rotated to rotate the feed roller 8 and the pull-out roller 27 in the paper discharge direction. Is discharged to.

As described above, in this embodiment, the rear side pressing roller 16 is supported by the bearing body 19 in the slide groove 17a so as to be able to come into contact with and separate from the feed roller 8. Therefore, unlike the conventional example, a pressing roller supporting structure is provided. Since it is not necessary to use a swing arm or a spring, it is possible to reduce the number of parts and simplify the configuration and assembly, and also to reduce the installation space and to make the entire apparatus compact.

(Effect of the Invention) As described in detail above, the present invention has an excellent effect that the number of parts can be reduced and the assembly can be easily performed, and the entire apparatus can be made compact.

[Brief description of drawings]

FIG. 1 is a sectional view of a printer embodying the present invention, and FIG.
The figure is a partial cross-sectional view showing the operating state of the front side presser roller.
The figure is a partial cross-sectional view showing the operating state of the rear presser roller,
The figure is a partial front view of the printer, and FIG. 5 is A in FIG.
-A sectional view taken along the line A and FIG. 6 are exploded perspective views showing a part of the configuration of the printer. In the figure, 8 ... Feed roller, 12 ... Guide frame, 16 ... Rear pressing roller, 17a ... Slide groove, 18 ... Cam shaft, 18a ... Planar cam surface, 18b ... Arc cam surface, 19 ... Bearing body, 19a … Bearings.

Claims (1)

[Scope of utility model registration request] 1. A printing apparatus comprising a feed roller (8) rotated to feed a print sheet, comprising: a slide groove (17a) provided in a frame (12) near the feed roller and having an opening at an upper portion thereof. And a cam surface (18a, 18a) that is rotatably arranged so as to pass through the bottom of the slide groove (17a) and that is displaced with the rotation.
b) and a cam shaft (18) having a cam surface (18a, 18a) of the cam shaft (18) that is slidably mounted in the slide groove (17a) through the opening.
It has a bearing part (19a) in the upper part while being abutted against b),
A bearing body (19) that can be moved up and down by the displacement of the cam surfaces (18a, 18b), and a shaft supported by the bearing portion (19a), and the feed roller (8) that is vertically supported by the bearing body (19). A printing apparatus comprising: a pressing roller (16) that comes into contact with and separates from the printing roller.