JPH07186489A - Chasis structure of printer - Google Patents

Abstract

PURPOSE:To obtain an inexpensive printer by eliminating the assembling work of a chasis by allowing the reinforcing rib erected from the bottom surface of a printer main body in a box frame shape by the integral molding with the main body to serve for a chasis having a platen, a platen motor and a carriage guide bar attached thereto. CONSTITUTION:Reinforcing ribs 21a, 21c erected from the bottom surface of a printer main body in a box frame shape by the integral molding with the main body are allowed to serve for a chasis having a platen having printing paper fitted thereto, the platen motor driving the platen and a carridge guide bar 41. As a result, an inexpensive printer can be obtained by eliminating the assembling work of the chasis. Further, the chasis receives external force such as distortion or the like in a well-blanced state and becomes hard to generate a crack as compared with a conventional product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a chassis for fixing mechanical parts such as a platen, a platen motor and a carriage in a printing device such as an electronic typewriter.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, an electronic typewriter has a main body composed of a plastic lower cover 101 and a plastic upper cover 103, and a mechanism such as a platen 105 inside the main body. The part was stored. As shown in FIG. 10, the mechanical components such as the platen 105 and the carriage 107 were assembled to the iron chassis 111 and then screwed to the lower cover 101.

[0003]

In the conventional electronic typewriter, the iron chassis 111 has been a factor of cost increase. That is, since the iron chassis 111 is punched and assembled through several steps such as pressing, the cost itself is high. In addition, the chassis 111 includes a platen 105 and a carriage guide bar 109.
Assemble the chassis 111 and the lower cover 1
No. 01 is required, and the large number of times of assembling also causes a cost increase. Further, it is also a factor of increasing the weight of the electronic typewriter, and there has been a demand for improvement of the chassis structure from the viewpoint of weight reduction.

Further, in the conventional electronic typewriter, FIG.
As shown in FIG.
On the other hand, the structure is fixed by the screw 115, and the screwing work has been desired to be improved as one of the causes for increasing the number of assembling steps. In addition, the motor harness 117 of the platen motor 113 has been guided around the rear corner of the chassis 111 to the control board 119 on the front side. Since the motor harness 117 may contact the power supply board 121, the cover 123 is attached to the power supply board 121. Conventionally, the cost has also been increased by mounting the cover 123.

Therefore, a first object of the present invention is to provide an inexpensive printing apparatus by eliminating the work of assembling the chassis. A second object of the present invention is to provide a chassis structure in which assembly of mechanical parts does not become difficult due to elimination of assembly work of the chassis. Further, a third object is to solve the problem of contact between the motor harness of the platen motor and the power supply board without increasing the cost. That is, an object of the present invention is to improve the structure of the chassis to reduce the number of assembling steps and reduce the cost as a whole.

[0006]

The chassis structure of the printer of the present invention, which has been made to achieve the above first object, comprises:
As described in claim 1, a chassis to which a platen on which a printing sheet is mounted, a platen motor that drives the platen, and a carriage guide bar that guides a carriage is attached is integrated with the main body from the bottom surface of the printer main body. It is characterized in that it also functions as a reinforcing rib standing upright in the shape of a box frame by molding.

The chassis structure of the printer of the present invention made to achieve the second object is, in the chassis structure of the printer according to claim 1, as described in claim 2, the chassis structure of the printer. Has a carriage guide bar mounting hole, at least one of which is a fool hole, and a bearing member slidable along the carriage guide bar is fitted and fixed in the fool hole when the carriage guide bar is mounted. And

Similarly, according to a third aspect of the present invention, there is provided a printing apparatus according to the present invention, wherein the chassis structure of the printing apparatus according to the first or second aspect is the chassis. A motor mounting portion is formed in the vicinity of the platen mounting portion, and a projection having a deformed tip is projectingly provided on the motor mounting portion, and an insertion hole through which the projection is inserted is provided above the pedestal metal fitting of the platen motor. With the pedestal metal fitting inserted in the protrusion, the lower side of the pedestal metal fitting is pulled obliquely downward by an elastic member, and the platen motor is fixed to the chassis and the printing apparatus main body through the elastic member and the projection, Moreover, it is characterized in that it is structured to be engaged with the platen.

On the other hand, in addition to the second object, the third object
According to a fourth aspect of the present invention, there is provided a chassis structure of a printing device, which is also configured to achieve the above object, in the chassis structure of the printing device according to the third aspect, a motor harness is attached to a motor mounting portion of the chassis from above. A guide groove that can be fitted is formed, and the guide groove is configured to be guided to the gap between the printer main body and the chassis through the guide groove.

[0010]

According to the chassis structure of the printer of the first aspect, the chassis is integrally formed with the main body, so that the assembly work of the chassis becomes unnecessary. Further, since the chassis also serves as a reinforcing rib standing upright in the shape of a box frame, not only does the weight of the main body itself increase, but the rigidity of the main body itself increases. That is, in addition to reducing the number of assembly steps, it is possible to contribute to weight reduction and strength increase.

According to the chassis structure of the printing apparatus of the second aspect, when the carriage guide bar is attached to the chassis, first the bearing member is inserted into the carriage guide bar, and the guide bar is inserted into the stupid hole. After that, the bearing member is displaced and fitted into the fool hole and fixed. As a result, the guide bar can be easily assembled even though the guide bar cannot be inserted from the side of the chassis as in the conventional case.

On the other hand, according to the chassis structure of the printing apparatus of the third aspect, when mounting the platen motor, first, the irregular insertion hole formed in the pedestal metal fitting of the platen motor is inserted into the irregular projection of the motor mounting portion. Let Next, the lower side of the pedestal metal member is pulled obliquely downward by an elastic member such as a pulling spring. At this time, the pulling direction is the direction in which the platen motor engages with the platen. As a result, the platen motor is firmly attached to the chassis in the form of three-point support of the protrusion, the elastic member and the platen. The elastic member also has a function of preventing backlash of the platen motor. As described above, according to the chassis structure of the printing apparatus of the third aspect, the platen motor can be easily assembled even in a narrow place in place of the conventional screw fastening structure, and the chassis is integrated. Acts to eliminate.

Further, according to the chassis structure of the printing apparatus of the fourth aspect, when mounting the platen motor, the motor harness may be fitted over the guide groove, and the guide groove bypasses the rear of the chassis. Without leading to the gap between the printer body and the chassis. This eliminates the risk of the motor harness coming into contact with the power supply unit or the like.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is an explanatory diagram showing an overall configuration of an electronic typewriter of an embodiment to which the present invention is applied.

As shown in FIG. 1, the electronic typewriter is
A keyboard 4 provided on the front portion of the main body case 2 for inputting characters, operation instructions, etc., a platen 6 for mounting printing paper, and a platen 6 which moves in parallel along the platen 6.
A print head unit 8 for printing characters and graphics on the print paper attached to the printer. The main body case 2 is composed of a plastic upper cover 11 and a lower cover 13,
When the upper cover 11 is removed, it is as shown in FIG.

As shown in FIG. 2, the lower cover 13 of this embodiment is integrally formed with a chassis 21 for mounting mechanical parts. As shown in the figure, the chassis 21 is also made to function as reinforcing ribs 21a to 21d continuously provided upright in the shape of a box frame. The reinforcing ribs 21a to 21d are formed in a double structure so as to press a part of the lower cover 13, as shown in FIG. By having a double structure,
Compared to the case of the configuration shown in FIG. 6C, the cross-section coefficient is large even with the same cross-sectional area, and the structure is light and strong.

FIG. 3 is a plan view of the lower cover 13, and the reinforcing rib / chassis 21 is shown by hatching. As you can see from this figure, the reinforcement rib and chassis 2
Since No. 1 is formed in a box frame shape in a substantially central portion of the lower cover 13, it contributes to increase the rigidity of the lower cover 13. In the conventional product, the iron chassis worked as a reinforcing member, but in this embodiment, the lower cover 13 and the chassis 21 are used.
Since it is integrally molded, the force distribution is uniform. In this respect, in the conventional product, the load is concentrated at the screw fastening point, so there was a risk of cracking the screw hole, etc.
In the present embodiment, there is no such concern, and there is an effect that it is made of plastic and is light, and it is hard to be damaged.

On the lower cover 13 of this embodiment, the mechanical parts (platen 6, platen motor 31, carriage body 33, ribbon cassette holder 35) are arranged in the state shown in FIG.
And the ribbon cassette 37) is mounted. Platen 6
As can be seen from FIG. 1B, since the lower cover 13 does not hinder the passage of the shaft, the assembly work does not increase even if the chassis 21 is integrally formed with the lower cover 13. However, as can be seen in the figure, the carriage guide bar 41 is obstructed by the lower cover 13 and cannot be inserted into the chassis 21 from the side. Therefore, in order to facilitate the assembling of the carriage guide bar 41, the device shown in FIG. 5 is devised.

That is, as shown in FIG. 5, the guide bar mounting hole 43 of the left chassis wall 21a is formed as a blind hole, and the hole diameter is the same as the outer diameter of the carriage guide bar 41, but the right chassis wall 21c. Guide bar mounting hole 45
Is a through-type stupid hole. When mounting the carriage guide bar 41 and the stupid hole 45, a bearing member 47 that can slide along the guide bar 41 is fitted into the staggered hole 45 and is prevented from rotating by the protrusion 49 of the chassis left side wall 21c. At the same time, the retaining rings 51 and 53 are attached to the retaining ring grooves formed in the guide bar 41. The retaining rings 51, 5
Reference numeral 3 is an E-ring or the like, which can be pushed in and fixed from above. Therefore, the carriage guide bar 4
When mounting the No. 1 on the chassis 21, first, the bearing member 47 is attached to the carriage guide bar 4 as shown by the dotted line.
1 through which the right end of the guide bar 41 is inserted into the fool hole 45, and then the left end is set in the mounting hole 43 on the opposite side, and then the bearing member 47 is displaced in the direction of the arrow to fool the hole 45. It is fitted in and fixed with snap rings 51, 53. In this way, even if the chassis 21 cannot be inserted from the side, the carriage guide bar 41 can be easily attached without any trouble.

Next, the mounting structure of the platen motor 31 which is a devised point of the embodiment will be described. Conventionally, as shown in FIG. 9, the platen motor 113 was fixed to the chassis 111 with a screw 115, but it was improved because the chassis was integrally molded with the lower cover, which made the screwing work difficult. It is a thing.

In this embodiment, as shown in FIG.
A motor mounting portion 63 is integrally formed near the platen mounting portion 61 of the chassis 21. The motor mounting portion 63 is provided with a projection 67 having an irregular shape with a small projection 65 facing upward. On the other hand, the same figure (B)
As shown in FIG. 7, a keyhole-shaped insertion hole 73 through which the projection 67 having the irregular tip is inserted is provided above the pedestal metal fitting 71 of the platen motor 31. Further, the pedestal metal fitting 71 is also provided with a notch 77 on which a pulling spring 75 can be hooked at a lower corner portion thereof.

The platen motor 31 is attached as shown in FIGS. First, the pedestal metal fitting is hung while the insertion hole 73 of the pedestal metal fitting 71 of the platen motor 31 is inserted into the protrusion 67, and then the pulling spring 75 is attached between the notch 77 and the claw 79 on the chassis 21 side.
As a result, the pedestal metal fitting 71 is pulled obliquely downward and rotated, and the key hole of the insertion hole 73 is displaced so that it cannot be removed from the protrusion 67. Further, as a result of the pulling spring 75 rotating clockwise in the figure, the drive pinion of the platen motor 31 is pressed against the gear 81 engaged with the platen 6. Thus, the protrusion 67, the pulling spring 75, and the platen-side gear 81 are supported at three points, and the platen motor 31 is firmly attached to the chassis 21. The pulling spring 75 also has a function of preventing backlash of the platen motor 31. As described above, according to the embodiment, the platen motor 31 can be easily assembled even in a narrow place in place of the conventional screw fastening structure, and a new trouble is not caused by integrating the chassis. ing.

Here, the platen motor 31 is connected to a control panel attached to the lower side of the keyboard and causes the platen 6 to perform operations such as line feed and page break at a predetermined timing. The motor harness 83 for this is
Conventionally, as shown in FIG. 9, the power supply board 121 may be contacted because it is guided around the back of the chassis 111 to the front side. In this embodiment, this point is also improved. Therefore, the improvements will be described.

As shown in FIGS. 6A and 7, the improvement is that a guide groove 87 into which the motor harness 83 can be fitted is formed in the motor mounting portion 63, and the guide groove 87 is inserted through the guide groove 87. The motor harness 83 is configured to be guided into the gap between the cover 13 and the chassis 21. As a result, there is no concern that the motor harness 83 will come into contact with the power supply board 85, and it is no longer necessary to attach the power supply cover 123 as in conventional products. Also, by integrating the chassis, the motor harness 8
Despite having to handle 3 of the motor harness 8 from above in this guide groove 87.
If the work of attaching the platen motor 31 while fitting 3 is carried out, the harness can be processed without any particular trouble. Therefore, the processing of the harness is easier than the assembly of the conventional product.

As described above, according to the present embodiment, not only does the chassis mounting work be eliminated by making the chassis integral with the lower cover, but also the chassis integration work can be done without any care. In addition to the carriage guide bar mounting and the platen motor mounting work that deteriorates in performance, no trouble occurs, and the processing of the motor harness is easier than before. As a result, the work of assembling the mechanical parts in the electronic typewriter can be significantly improved, and the cost reduction effect is high due to the reduction of the man-hours. In addition, the chassis itself can be easily molded at the same time as the lower cover by injection molding, etc., and the cost reduction effect is high in terms of chassis processing man-hours. In addition, the ribs and chassis are continuously projected in the shape of a box frame, which is perfect for strength and contributes to weight reduction.

Although one embodiment has been described above, the present invention is not limited to this embodiment, and various modifications can be made without departing from the spirit of the invention.

[0027]

As described above, according to the chassis structure of the printer of the present invention, it is possible to provide an inexpensive printer without the work of assembling the chassis. Moreover, external forces such as twisting are received in a well-balanced manner, and cracking is less likely to occur than in conventional products. In addition, claim 2,
According to the structure described in 3, it is possible to prevent the assembly of the mechanical parts from being difficult due to the elimination of the assembly work of the chassis. Further, according to the structure of claim 4, the problem of contact between the motor harness of the platen motor and the power supply board can be solved without increasing the cost, and the workability of harness handling is improved compared to the conventional case.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of an electronic typewriter as an embodiment, (A) showing a state in which an upper cover is covered,
(B) is a view of a state in which the upper cover is removed.

FIG. 2 shows a structure of a lower cover in the embodiment,
(A) is a perspective view, (B) is a cross-sectional view of a main part thereof, and (C) is a cross-sectional view for comparison.

FIG. 3 is a plan view of the lower cover of the embodiment.

4A and 4B are cross-sectional views of a mechanical component in an attached state in an embodiment, FIG. 4A is a view of the main body from the center to the right, and FIG. 4B is a view of the same from the center to the left. .

FIG. 5 is a cross-sectional view showing a mounting structure of a carriage guide bar in the embodiment.

FIG. 6 is an explanatory view of a disassembled state showing a platen motor mounting structure in the embodiment.

FIG. 7 is a diagram showing the assembled state of the platen motor mounting structure in the embodiment as seen from the center to the left.

FIG. 8 is a plan view in an assembled state showing a platen motor mounting structure in the embodiment.

FIG. 9 is a sectional view of a conventional example.

FIG. 10 is a perspective view showing a conventional chassis structure.

[Explanation of symbols]

2 ... Main body case, 4 ... Keyboard, 6 ... Platen, 8 ... Print head part, 11 ... Top cover,
13 ... Lower cover, 21 ... Chassis, 21a-2
1d ... Reinforcing rib, 31 ... Platen motor, 33
... Carriage main body, 35 ... Ribbon cassette holder, 37 ... Ribbon cassette, 41 ... Carriage guide bar, 43 ... Guide bar mounting hole, 45 ...
Guide bar mounting hole (stupid hole), 47 ... Bearing member,
49 ... Protrusion, 51, 53 ... Retaining ring, 61 ...
Platen mounting part, 63 ... Motor mounting part, 65 ...
Small protrusion, 67 ... Protrusion, 71 ... Pedestal metal fitting, 73 ...
..Insertion holes, 75 ... extension springs, 77 ... notches, 7
9 ... claw, 81 ... gear, 83 ... motor harness, 85 ... power supply board, 87 ... guide groove.

Claims (4)

[Claims] 1. A box frame in which a platen on which printing paper is mounted, a platen motor for driving the platen, and a carriage guide bar for guiding a carriage are integrally formed with the main body from the bottom surface of the printing apparatus main body. The chassis structure of the printing device is characterized in that it also functions as a reinforcing rib standing upright. 2. The chassis structure of the printing apparatus according to claim 1, wherein a carriage guide bar mounting hole, at least one of which is a fool hole, is formed in the chassis, and the carriage guide bar is slid along the carriage guide bar when mounting. A chassis structure of a printing apparatus, wherein a movable bearing member is configured to be fitted in and fixed to the fool hole. 3. The chassis structure of the printing apparatus according to claim 1, wherein a motor mounting portion is formed near the platen mounting portion of the chassis, and the motor mounting portion has a deformed tip. And an insertion hole through which the protrusion is inserted on the upper side of the pedestal metal fitting of the platen motor, and with the pedestal metal fitting inserted in the projection, the lower side of the pedestal metal fitting is pulled diagonally downward by an elastic member. A chassis structure for a printing apparatus, wherein the platen motor is fixed to the chassis and the printing apparatus main body through the elastic member and the protrusion and is engaged with the platen. 4. The chassis structure of the printing apparatus according to claim 3, wherein a guide groove into which a motor harness can be fitted from above is formed in a motor mounting portion of the chassis, and the printing apparatus main body and the chassis are provided via the guide groove. A chassis structure of a printing device, which is configured to be guided to a gap between the printer and the printer.