JPH0214427Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a mechanism for transporting the head carrier of a serial printer in the direction of the digits, and more specifically, the invention relates to a mechanism for transporting the head carrier of a serial printer in the column direction. It's about structure.

(Prior art) Endless toothed belts, so-called timing belts, have traditionally been used as a means of transporting the head carrier carrying the print head of a serial printer in the direction of the printer. In order to easily perform the separation, the present applicant previously proposed a method in Utility Application No. 55-136236 (Utility Model Application No. 57-57951) in which the head carrier is provided with a toothed female mold of the toothed belt. Proposed.

FIG. 3 is a diagram showing the connecting portion between the head carrier and the toothed belt. The head carrier 2 is formed with a connecting portion 21 with the toothed belt 5. Tooth profile 5-a, 5-
Female tooth profile 21- that engages with b, 5-c, and 5-d
a, 21-b, 21-c, and 21-d are formed. The toothed belt 5 is inserted into the female toothed shapes 21-a-21-d in the direction of arrow 12, and the head carrier 2 and the toothed belt 5 are connected.

(Problems to be Solved by the Invention) However, in this structure, coupling play may occur due to the difference in thickness dimension of the toothed belt and the difference in dimension error of the belt insertion recess of the head carrier.
This causes printing misalignment in the digit direction during reciprocating printing,
In addition, there is a problem in that the head carrier and the toothed belt may become uncoupled due to a simple external force when the ink ribbon is attached to and detached from the printer. In order to solve this problem, it may be possible to sufficiently control the tightening margin between the belt and the belt, but this requires processing the joint portion with high precision, leading to an increase in cost.

The present invention was devised in view of these problems, and its purpose is to simplify the assembly and disassembly operations without requiring particularly high machining accuracy, and to improve the head carrier. To provide a printing head transport mechanism for a serial printer capable of performing high-quality printing by tightly coupling a printer and an endless toothed belt.

(Means for Solving the Problems) In order to solve these problems, the present invention provides an endless belt with a tooth profile formed thereon, and a head carrier that carries a printing head and has a connecting part that can be detachably attached to the endless belt. The joint part has a groove that is open on both ends of the endless belt in the running direction and the side opposite to the head carrier, and one inner wall of the groove has a female groove that corresponds to the tooth profile of the endless belt. A tooth-shaped recess is formed on the other inner wall, and an inclined protrusion whose protrusion becomes larger toward the head carrier is formed at a position facing the female tooth-shaped recess.

(Function) When the endless belt is inserted into the groove in line with the tooth-shaped recess formed in the groove of the coupling part, the tooth profile of the endless belt is expanded by the protrusion within the tooth-shaped recess of the groove, and the closer to the head carrier the closer the endless belt is to the joint. It will be joined to the section. Therefore, even when a large load is applied, such as when switching the running direction during reciprocating printing, there is no play between the belt and the head carrier, and high quality printing can be performed. Further, by pulling the endless belt out of the groove, the head carrier and the endless belt can be uncoupled.

(Example) Therefore, the details of the present invention will be explained below based on the illustrated example.

FIG. 1 is a perspective view showing a print head transport mechanism of a serial printer embodying the present invention. A head carrier 2 carries a print head 1 and is supported by guide shafts 3 and 4 so as to be slidable in the direction of the digits. .
5 is a toothed endless belt, a part of which is connected to the head carrier 2 for traction. 6 is toothed belt 5
7 is an ink ribbon, and 8 is printing paper. The toothed belt 5 has a belt driven pulley 9
and a drive pulley directly connected to the motor 6, and is given tension. Furthermore, flanges 10 and 11 are attached to each pulley to prevent the toothed belt from falling off.

FIG. 2 is a view of the head carrier 2 shown in FIG. 1 viewed from below, and shows the connecting portion between the head carrier 2 and the toothed belt 5. As shown in FIG.

The head carrier 2 is formed with a joint part 22 with the toothed belt 5, and this joint part 22 is formed with a groove that penetrates in the moving direction of the head carrier 2 and has an opening 29 on the side opposite to the side where it is attached to the head carrier 2. 23 is formed. One inner wall 24 forming this groove 23 has a tooth profile 5-a of the toothed belt 5,
Female tooth-shaped recesses 21-a, 21-b, 21-c, and 21-d are formed to engage with the tooth-shaped recesses 21-b, 5-c, and 5-d, and the other inner wall 25 is provided with tooth-shaped recesses 21-d.
a, 21-b, 21-c, and 21-d, slanted protrusions 22-e, 22-f, which protrude more from the opening 29 side toward the head carrier side.
22-g and 22-h are formed.

These tooth-shaped recesses 21-a, 21-b, 21-
c, 21-d are parallel to the groove 23, and protrusions 22-e, 22-f, 22-g, 22-h are
Since the amount of protrusion on the opening 29 side is small, the molding die can be easily pulled out, and therefore it can be formed integrally with the head carrier 2 by plastic molding or aluminum die casting. It is.

In this embodiment, the tooth profile 5-a of the toothed belt 5
5-d and the female toothed recesses 22-a to 22-d, and then
d into the head carrier 2 through the opening 29, the protrusions 22-e to 22-h of the head carrier 2 push the back surface of the toothed belt 5, and the female tooth profile 22-a
~22-Press it to the d side. In this pushing process, the toothed portions 5-a to 5-d have a large wall thickness and high rigidity, and are elastically deformed in the thickness direction. −
Recesses 21-a, 21-c, 21 gradually along h
Since it deforms within -d, it can be easily pushed to the bottom of the groove 23.

As a result, the toothed portions 5-a to 5-d of the belt 5,
The carrier side portion of the tooth-shaped recess 2 of the coupling portion 22
2-a to 22-d will fully expand, regardless of the machining accuracy of the concave portion of the joint portion 22.
The belt 5 is coupled to the carrier 2 in close contact.

After installation, when the toothed belt 5 is stretched around the driven pulley 9 and the rotating shaft of the motor 6 and a predetermined tension is applied to the belt 5, the toothed belt tries to return to a straight state, so that the female toothed recess 22 -a to 22-d or the protrusions 22-e to 22-h are increased in force, and the toothed belt 5 and the head carrier 2 are securely fastened.

In this state, when the motor 6 rotates and the belt 5 is driven, the head carrier 2 receives a driving force via the coupling portion 22 and moves in the printing direction.

By the way, the head carrier 2 is most strongly connected to the belt 5 by the protrusions 22-e to 22-h at the bottom of the connecting portion 22, that is, at a location as close as possible to the head carrier 2, so that the guide shafts 3, 4 Even if there is play between them, the head carrier 5 is prevented from tilting. Also, during reciprocating printing, if a large load is applied to the belt 5 when switching between the forward process and the backward process, it will be pushed in the direction of the female tooth-shaped recesses 22-a to 22-d or the protrusions 22-e to 22h. The applying force is increased, the play between the toothed belt 5 and the head carrier 2 is eliminated, and high quality printing is made possible.

Even if the belt 5 is inadvertently lifted when replacing an ink ribbon or the like, the belt 5 will not be able to hold the protrusion 22-
Since it is elastically pressed against the groove 23 by e to 22h, it will not easily come off with the force of a simple touch.

On the other hand, if it becomes necessary to remove the belt 5 from the head carrier 2 for maintenance etc., the connecting portion 2
2 and the belt 5 and scoop the belt up a little, or pull it up with a little force to lift the belt 5 off the protrusions 22-e to 22h. If the belt 5 is pulled out from the groove 23 at this stage,
The engagement between the carrier 2 and the belt 5 can be easily released.

In this example, the protrusions are provided in each of the tooth-shaped recesses 22-a to 22-d, but it is clear that similar effects can be achieved even if the protrusions are provided in at least one of the tooth-shaped recesses.

(Effects of the invention) As explained above, in the invention, a groove is formed in the joint part with openings on both ends in the running direction of the endless belt and on the side opposite to the head carrier, and one inner wall of the groove is opened. The inner wall of the belt has a female tooth-shaped recess that corresponds to the tooth shape of the endless belt, and a protrusion is formed on the other inner wall at a position opposite to the female tooth-shaped recess, making it easier to connect and separate the carrier and belt. By expanding the tooth profile of the belt within the concave portion of the joint while maintaining the same, the belt and head carrier can be reliably joined regardless of the machining accuracy of the carrier joint. Even with large load fluctuations that occur during switching, no backlash occurs, and reciprocating printing can be performed with high printing quality.

Furthermore, in the present invention, the amount of protrusion of the protrusion is increased toward the carrier, so that when the belt and head carrier are connected, the belt enters along the slope of the protrusion, making it easy to insert the belt without applying excessive force. Not only can this be done, but it can also be coupled as close as possible to the carrier, preventing the carrier from tilting and ensuring high printing accuracy.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the print head transport mechanism of a serial printer embodying the present invention, and FIG.
FIG. 3 is a schematic perspective view showing the joint between the head carrier and the toothed belt. FIG. 3 is a schematic perspective view showing the joint between the conventional head carrier and the toothed belt. 1...Print head, 2...Head carrier, 5
...Toothed belt, 22...Joining portion, 22a-22
-d...Tooth-shaped recess, 22-e to 22-h...Protrusion, 23...Groove, 24, 25...Inner wall, 29...
Opening.

Claims (1)

[Scope of utility model registration request] It has an endless belt on which a tooth profile is formed, and a head carrier that carries a printing head and has a connecting part that can be attached to and detached from the endless belt,
A groove is formed in the joint portion and is open at both end sides in the running direction of the endless belt and on three sides opposite to the head carrier, and one inner wall of the groove has a female tooth-shaped recess corresponding to the tooth profile of the endless belt. and a print head transfer mechanism for a serial printer, characterized in that the other inner wall is formed with an inclined protrusion that protrudes more toward the head carrier at a position facing the female tooth-shaped recess.