JP3156916B2 - Idler pulley holder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idler pulley holder for supporting an idler pulley on which a timing belt for moving a print head of a printer is hung.

[0002]

2. Description of the Related Art A timing belt for moving a print head of a printer has teeth formed inside.
The timing belt is stretched between a toothed motor-side gear that is rotationally driven by a driving motor and an idler pulley that is rotatably supported by an idler pulley holder.

Since the timing belt needs to be given a predetermined tension for smooth movement of the print head, the idler pulley holder is given a tension by an idler pulley spring. That is, the idler pulley is slidably attached to the components of the printer in the direction of tension and relaxation of the timing belt, and the idler pulley holder is biased in the direction in which the timing belt is tensioned.

[0004]

However, the above-mentioned conventional idler pulley holder has the following problems. That is, when assembling the printer, it is necessary to slide the idler pulley holder toward the motor side gear against the elastic force of the idler pulley holder spring, and attach the timing belt to the idler pulley in this state. This is a task of pushing the idler pulley with one hand and hanging the timing belt on the idler pulley with the other hand, and requires skill for quick and reliable work.

If the drive of the timing belt is suddenly stopped during printing, the idler pulley spring becomes slack, and as a result, tooth jump occurs between the motor side gear and the timing belt. When this tooth skipping occurs, a deviation occurs between the position of the print head recognized by the control unit of the printer and the actual position of the print head, thereby causing a print error.

In order to prevent such tooth skipping, a cylindrical stopper is fitted into the guide boss after the timing belt is attached, so that the idler pulley spring does not loosen even when the driving of the timing belt is suddenly stopped. . However, in this case, even if tooth skipping can be prevented, the number of parts increases and the number of working steps also increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and enables a work for attaching a timing belt to be performed quickly and easily. Moreover, tooth jumping which causes printing errors can be performed without increasing the number of parts and the number of working steps. It is an object of the present invention to provide an idler pulley holder capable of preventing the idler pulley.

[0008]

According to a first aspect of the present invention, there is provided an idler pulley holder which rotatably supports an idler pulley on which a timing belt for moving a print head of a printer is hung on a pulley support, and which is a component of the printer. with slidably mounted along a direction tension and relaxation of the timing belt, the idler pulley holder is urged in a direction to pull the timing belt, the data in the engaging portion formed in the structural member
Moving in the direction of tension and relaxation of the
When the engaging claw is engaged with the engaging portion against the urging, the idler pulley is attached with the timing belt loosened.
Located in a location that is, when releasing the engagement, the A
Idorapuri is located where the predetermined tension is applied to the timing belt, even Thai <br/> timing belt is pulled in a direction to relax in a state where the engagement is released, and the engagement pawl and the engagement portion Thereby , the idler pulley is prevented from sliding.

In the idler pulley holder according to a second aspect of the present invention, both the engaging portion and the engaging claw are plate-like members having an engaging plane in a direction orthogonal to a direction in which the timing belt is tensioned and relaxed. The engagement and disengagement of the engagement claw with the engagement portion can be performed only by moving the engagement claw in a direction orthogonal to the direction in which the timing belt is tensioned and relaxed.

[0010]

1 is a drawing of an idler pulley holder according to an embodiment of the present invention, wherein FIG. 1A is a schematic front view, FIG. 1B is a schematic bottom view, and FIG. 2 is a drawing showing a state in which the timing belt is tensioned by the idler pulley holder according to the embodiment of the present invention, wherein FIG. 2A is a schematic front view, FIG. 2B is a schematic plan view, 3 is a drawing showing a state in which the timing belt is relaxed by the idler pulley holder according to the embodiment of the present invention, wherein FIG. 3A is a schematic front view, FIG. 3B is a schematic plan view, FIG. 4 is a schematic front view of a guide groove of a base member which is a component of a print to which the idler pulley holder according to the embodiment of the present invention is attached.

In the present specification, the tension means that the timing belt 300 is stretched with a predetermined tension, and the relaxation means that the predetermined tension comes off from the timing belt 300 and becomes loose. Shall be referred to.

An idler pulley holder 100 according to an embodiment of the present invention rotatably supports an idler pulley 200 around which a timing belt 300 for moving a print head of a printer (not shown) is hung on a pulley support portion 110, and the Base member 400 as a constituent member
The timing belt 300 is slidably mounted along a direction in which the timing belt 300 is tensioned and relaxed, and is urged in a direction in which the timing belt 300 is pulled.

First, a base member 400, which is a component of a printer to which the idler pulley holder 100 is slidably mounted, will be described. The base member 400 is formed by bending a metal plate, and has a guide bar (not shown) for guiding the movement of a print head (not shown) mounted in a lateral direction. The base member 400 is provided with a toothed motor-side gear (not shown) that meshes with the teeth of the timing belt 300 and drives the timing belt 300.

An idler pulley holder 1 is provided on the side of the base member 400 opposite to the side on which the motor-side gear is provided.
A guide groove 410 for slidably mounting 00 in a direction in which the timing belt 300 tensions and relaxes is provided. As shown in FIG. 4, the guide groove 410 has an important portion 411 from the side of the base member 400, a narrow cut portion 412 connected to the important portion 411, and a narrow cut portion 412. A heart-shaped notch 413 having a substantially heart shape is provided in a row.

Further, an engagement portion 420 having an opening 421 into which a guide boss 130 described later is fitted is provided on the inner edge of the heart-shaped cut portion 413, that is, on the side where the motor-side gear is provided. It is formed by cutting and raising.

The idler pulley holder 100 has a substantially U-shaped pulley support 110 for rotatably supporting the idler pulley 200, and a pulley support 11.
Guide portion 120 extending outward from the bottom portion 112
And a cylindrical guide boss 130 protruding from the guide portion 120 and an arm portion 140 extending from the guide portion 120 in parallel with the guide boss 130 and integrally formed of a synthetic resin or the like. It is.

First, the pulley supporting portion 110 has a pair of side portions 111 facing in parallel and the bottom portion 112 connecting the pair of side portions 111. A substantially U-shaped support recess 111 </ b> A is cut into the side portion 111. The shaft 210 of the idler pulley 200 is fitted into the support recess 111A, and the idler pulley 2
00 is rotatably supported.

The bottom 11 of the pulley support 110
The guide portion 120 extending from the guide groove 41
A pair of back side guide protrusions 122A located on the back side of the base member 400 with a pair of front side guide protrusions 122B formed on the front side. That is,
The back side guide protrusion 122A and the front side guide protrusion 122B
Between the base member 400 and, more specifically, the edge of the narrow notch 412, so that the idler pulley holder 1
00 is slidably attached to the base member 400.

Further, a substantially cylindrical guide boss 130 protrudes from a substantially center of the guide portion 120.
The guide boss 130 is connected to the opening 42 of the engagement portion 420.
1 is a part that fits into the idler pulley holder 1
The slide No. 00 is restricted only in the direction in which the timing belt 300 is tensioned and relaxed. A tapered surface is provided at the tip of the guide boss 130 so as to be easily inserted into the opening 421.

Further, the guide boss 130 is attached to the timing belt 300 with respect to the idler pulley holder 100.
2 is also a portion where the idler pulley spring 500 that urges in the direction of pulling (in the direction of arrow A in FIG. 2A) is externally fitted. That is, the idler pulley spring 50
0 urges the idler pulley holder 100 interposed between the engaging portion 420 and the guide portion 120 and slidable by the guide groove 410 in a direction in which the timing belt 300 is pulled.

On the other hand, from one of the front side guide projections 122B, the arm portion 14 parallel to the guide boss 130 is provided.
0 is extended. The arm 140 has a substantially triangular tip claw 141 at the tip. An engagement claw 142 protruding from the middle part of the arm 140 toward the guide boss 130 is provided.

When viewed from the engaging portion 420, the engaging claw 142 is positioned on the side against the urging force of the idler pulley spring 500, that is, on the right side as shown in FIG. When combined, the idler pulley spring 500 maintains the compressed state. For this reason, the idler pulley 200 is located at a place where the timing belt 300 relaxes.

On the other hand, when the engaging claw 142 is disengaged from the engaging portion 420 and is positioned on the opposite side of the engaging portion 420, that is, on the left side as shown in FIG. 500 is in an extended state, and the idler pulley 200 is located at a position where a predetermined tension is applied to the timing belt 300.

The engagement and release of the engagement claw 142 with the protrusion 420 is performed by the operator holding the tip claw 141 of the arm 140 with his / her finger and displacing it in the direction of arrow B in FIG. .

Next, a procedure for mounting the timing belt 300 in the printer using the idler pulley holder 100 having the above-described configuration will be described.

First, with the idler pulley spring 500 externally fitted to the guide boss 130, the base member 400
Attach to That is, the important part 4 of the guide groove 410
The rear guide projection 122A and the front side throat projection 122B of the guide part 120 are fitted into the narrow notch part 412 from 11 and the guide boss 130 is inserted into the opening 421 of the engagement part 420. At this time, the distal claw 141 of the arm 140 is smoothly displaced in the direction of arrow A shown in FIG. As a result, the idler pulley holder 100 is
That is, it is slidably attached to 0.

Next, the arm 140 is displaced in the direction of arrow B. At the same time, the idler pulley holder 100 is pressed in the direction opposite to the arrow A against the elastic biasing force of the idler pulley spring 500. If the engaging claw 142 of the idler pulley holder 100 exceeds the engaging portion 420, the arm portion 1
40 is returned to the original position. Then, the force applied to the idler pulley holder 100 is released. Thus, the idler pulley holder 100 is locked at the position shown in FIG.

In this state, the idler pulley 200
The timing belt 300 is located at a place where the timing belt 300 relaxes. For this reason, in this state, the timing belt 3
00 can be easily attached to a toothed motor-side gear (not shown).

When the timing belt 300 is attached, the arm 140 is displaced again in the direction of arrow B,
The engagement between the engagement claw 142 and the engagement portion 420 is released. Then, along with this release, the idler pulley holder 100 returns to its original position, that is, a place where a predetermined tension is applied to the timing belt 300 by the elastic biasing force of the idler pulley spring 500.

This state, that is, the timing belt 30
In a position where a predetermined tension is applied to the timing belt 300 and printing is being performed, if driving of the timing belt is suddenly stopped for some reason, the timing belt 300 is stopped.
Is pulled in the relaxing direction, so that the idler pulley holder 100 is pulled toward the toothed motor-side gear. However, since the engaging claw 142 is provided on the left side of the engaging portion 420 (the side opposite to the side on which the toothed motor side gear is provided), the idler pulley holder 100 is brought into contact with the toothed motor by the contact of both. It does not move to the side gear.

That is, even if the timing belt 300 is pulled in the direction of relaxation, the engaging claw 142
With 40, the slide in the direction in which the timing belt 300 is relaxed is prevented. Even in this state, since a predetermined tension is applied to the timing belt 300, there is no slack between the timing belt 300 and the toothed motor-side gear, so that tooth skipping does not occur.

[0032]

The idler pulley holder according to the present invention has the following features.
The idler pulley on which the timing belt for moving the print head of the printer is hung is supported rotatably on the pulley support portion, and is attached to the components of the printer so as to be slidable along the tension and relaxation directions of the timing belt. An idler pulley holder urged in a direction to pull the timing belt, comprising an engagement claw that can be engaged with an engagement portion formed on the component member, wherein the engagement claw resists the urging. When the timing belt is relaxed, the idler pulley is located at a place where the timing belt relaxes, and when the engagement is released, the idler pulley is located at a place where a predetermined tension is applied to the timing belt. , The sliding is prevented by the engaging claw and the engaging portion.

Therefore, when assembling the printer,
The idler pulley holder is slid in the direction in which the timing belt relaxes, and the engaging claw is engaged with the engaging portion to maintain the state. As a result, the timing belt
It is easier to hang on the idler pulley. In addition, since the idler pulley holder is stopped at that position, that is, the position where the timing belt is relaxed, the idler pulley holder does not need to be held by hand, and the timing belt can be hung on the idler pulley with both hands. Therefore, the work of attaching the timing belt can be easily performed even by a non-expert.

On the other hand, when the engagement between the engaging claw and the engaging portion is released while the timing belt is hung on the idler pulley, the engaging portion and the engaging claw come into contact with each other. Do not slide in the direction of relaxation. Therefore, even if the drive of the timing belt is suddenly stopped during printing, the idler pulley holder does not slide in the direction in which the timing belt relaxes. For this reason, since a predetermined tension is always applied to the timing belt, there is no slack between the timing belt and the toothed motor-side gear, so that tooth skipping that causes print errors does not occur.

Further, the engagement and disengagement of the engagement claw with the engagement portion can be performed only by applying an external force to the engagement claw. Are not engaged or disengaged. Therefore, the mounting operation of the timing belt can be performed smoothly, and even if the driving of the timing belt is suddenly stopped at the time of printing, the timing belt is not loosened, which causes tooth skipping.

[Brief description of the drawings]

1A and 1B are drawings of an idler pulley holder according to an embodiment of the present invention, wherein FIG. 1A is a schematic front view and FIG. 1B is a schematic bottom view.

FIGS. 2A and 2B are diagrams showing a state in which the timing belt is tensioned by the idler pulley holder according to the embodiment of the present invention, wherein FIG. 2A is a schematic front view, and FIG. It is.

3A and 3B are diagrams showing a state in which the timing belt is relaxed by the idler pulley holder according to the embodiment of the present invention, wherein FIG. 3A is a schematic front view and FIG. 3B is a schematic plan view. It is.

FIG. 4 is a schematic front view of a guide groove of a base member which is a constituent member of a print to which the idler pulley holder according to the embodiment of the present invention is attached.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 idler pulley holder 110 pulley support portion 142 engagement claw 200 idler pulley 300 timing belt 400 base member (component of printer) 420 engagement portion

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-255882 (JP, A) JP-A-4-115969 (JP, A) Full-fledged 1986-201848 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) B41J 19/20

Claims (2)

(57) [Claims] An idler pulley, on which a timing belt for moving a print head of a printer is hung, is rotatably supported by a pulley support portion, and is slidable in a component of the printer along a direction in which the timing belt is tensioned and relaxed. In an idler pulley holder that is attached and urged in a direction to pull the timing belt, the tie is formed on an engagement portion formed on the constituent member.
In the direction perpendicular to the tensioning and relaxing direction of the
And the idler pulley relaxes the timing belt when the engaging claw is engaged with the engaging portion against the bias. so
When the engagement is released , the idler pulley is located where a predetermined tension is applied to the timing belt, and the engagement is released.
Be pulled in the direction in which the timing belt relaxes state, by said engagement pawl and the engagement portion, the Aidorapu
Idler pulley holder characterized in that sliding of the tool is prevented. 2. The engaging part and the engaging claw are both provided in the tab.
Direction perpendicular to the tensioning and relaxing direction of the imming belt
The engagement claw is engaged with the engagement portion by the engagement claw, and the engagement claw is formed by the timing member.
In the direction perpendicular to the direction in which Gubert's tension and relaxation occur
The idler pulley holder according to claim 1, wherein the idler pulley holder can be moved only by moving the pulley.