JPH0734686Y2 - Toothed belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a toothed belt used in a belt transmission, and more particularly to the structure of a drive pin for driving a carriage or the like.

[Prior Art] As a conventional printer head traveling mechanism using a toothed belt, there is, for example, one described in JP-A-49-19730.

In this type, a toothed belt having a large number of teeth equidistantly provided inside an endless belt main body is wound around two toothed pulleys arranged in parallel at a predetermined distance in the carriage movement direction. There is. A holder is attached to the toothed belt, and a guide roller rotatably supported by the holder is engaged with an elongated hole of a carriage movably supported by two guide rails arranged in parallel with each other. is doing. A printer head is attached to the carriage, and the carriage is driven by a toothed belt to reciprocate the printer head.

Then, when the toothed belt is run by the rotational force of the driving side toothed pulley, the carriage is guided by the guide rail by the driving force of the pin running integrally with the toothed belt to move in the row direction of the print sheet. . When the pin reaches the toothed pulley and changes from straight running to curved running, the pin moves in the opposite direction through the elongated hole of the carriage while moving the carriage to the end of the line, and 180 degrees around the toothed pulley. Rotating moves the carriage in the opposite direction.

[Problems to be Solved by the Invention] However, in such a toothed belt of a conventional printer head traveling mechanism, the guide roller is attached via a holder so that the guide roller does not come into contact with the toothed pulley. Since it was rotatably supported, the axis of the guide roller was largely eccentric to the pitch line of the toothed belt. Therefore, when the carriage travels, a moment is generated in the holder attachment part of the toothed belt, the toothed belt vibrates based on this moment and print load fluctuation, and the vibration is transmitted to the carriage. There is a problem that the printed font is greatly disturbed at the turn portion.

The present invention has been made in view of the above conventional problems, and is a pitch line of a belt body (which is called a center line of meshing with a toothed pulley in the thickness direction, specifically, a tooth line). (The position of about half of the belt thickness including the tooth portion of the attached belt) and the center line of the shaft body of the drive pin are made to coincide with each other, and the drive pin is formed into two plate shapes and two shaft bodies. It is an object of the present invention to solve the above problems by making the structure simple and inexpensive, and preventing the toothed belt from vibrating due to the fluctuation of the driving force.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an endless continuous belt body with a large number of teeth at equal intervals, and the belt body has end portions from both sides in the width direction. In a toothed belt provided with driving pins projecting from each of them, the driving pin includes a first plate-shaped piece having a square window that engages with the tooth, and the first plate-shaped piece.
A second plate-shaped piece that cooperates with the plate-shaped piece to sandwich the belt body, and square holes that fit into both ends of the first plate-shaped piece and the second plate-shaped piece. The present invention is characterized in that it has two shafts provided by aligning the center line of the shaft with the pitch line of the belt body.

[Operation] Thus, in the present invention, the drive pins whose end portions respectively project from both sides in the width direction of the belt body are formed by two plate-shaped pieces and two shaft bodies, and By matching the axial center line with the pitch line of the belt body, a moment is not generated in the toothed belt by the driving force acting on the drive pin, vibration is prevented and the toothed belt is moved at a constant speed. You can drive in.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

1 is a plan view showing an embodiment of the present invention, FIG. 2 is a perspective view showing a shaft body before mounting, and FIG. 3 is a perspective view showing a plate piece before mounting. FIG. 4 is an explanatory view showing an example of a usage state of the present invention, and FIGS. 5 (a) to (d) are views for explaining the operation of the present invention.

First, the structure will be described. 1 shown in FIGS. 1 to 3 is an endless continuous belt main body, inside of which a large number of teeth 2 having a trapezoidal cross section in the longitudinal direction are provided at equal intervals. There is.

Reference numeral 3 denotes a drive pin fixed to the belt main body 1. The drive pin 3 holds a part of the belt main body 1 from both sides.
The plate-shaped pieces 4 and 5, and the two shaft bodies 6 fitted to the ends of the belt body 1 protruding from both sides in the width direction when the belt body 1 is sandwiched by the plate-shaped pieces 4 and 5, respectively. It is formed by 6 and 6.

Of the two plate-shaped pieces 4 and 5, the first plate-shaped piece 4 is provided with a bulging portion 4a in which the midway portion of the longitudinal direction thereof is bulged to the one side by the thickness of the belt body 1, As a result, an engaging groove 4b corresponding to the width of the belt body 1 is formed on the other surface side. further,
The bulging portion 4a of the first plate-shaped piece 4 is provided with a square window 4c with which the teeth 2 of the belt body 1 engage, and the second window is provided at both ends.
A positioning hole 4d for positioning the plate-shaped piece 5 is provided.

The second plate-shaped piece 5 is composed of a flat plate having the same length and width as the first plate-shaped piece 4, and has a projection 5a for positioning which engages with the positioning hole 4d on one surface side thereof. They are provided respectively.

Further, the shaft body 6 is in the shape of a roller, and an angle at which the ends of both plate-like pieces 4 and 5 in the state where the first plate-like piece 4 and the second plate-like piece 5 are overlapped are fitted. The hole 6a is provided so as to penetrate in the axial direction. The setting position of the square hole 6a is provided so that the shaft center line O of the shaft body 6 coincides with the pitch line L of the belt body 1 when fitted to the ends of the two plate-like pieces 4 and 5. .

Thus, the assembling work of the toothed belt A according to this embodiment is performed by the following procedure.

First, as shown in FIG. 2, the first plate-like piece 4 is made to face the surface of the belt body 1 on which the teeth 2 are present, and the second plate-like piece 5 is made to face the other surface.
Face. Then, as shown in FIG. 3, the square window 4c provided on the bulging portion 4a of the first plate-shaped piece 4 is engaged with one of the teeth 2 of the belt body 1 and the two positioning holes 4d are formed. The first plate-shaped piece 4 and the second plate-shaped piece 5 are formed by engaging the two protrusions 5a with each other.
The belt body 1 is sandwiched between and.

Next, the end portions of the first plate-shaped piece 4 and the second plate-shaped piece 5 that are superposed on each other are inserted into the square holes 6a, and the shaft bodies 6 are respectively attached to both end portions of both plate-shaped pieces 4 and 5. Fit and fix. And both plate-like pieces 4,
The drive pin 3 is fixed to the belt main body 1 by fastening each end of the shaft 5 and the shaft body 6 by caulking or the like, and thus the toothed belt A according to this embodiment is formed.

Thus, in the toothed belt A according to this embodiment, the drive pin 3
The axis O of the line coincides with the pitch line L of the belt body 1. Therefore, when the drive pin 3 is pressed in the longitudinal direction of the belt body 1, the pressing force acts on the center of the toothed belt A, and therefore, depending on the action of the driving force, the belt body 1
No moment is generated in.

The toothed belt A is used, for example, in an apparatus as shown in FIG.

That is, FIG. 4 shows an example of a carriage running drive device in a serial dot printer, and is a view showing a mechanism for reciprocating linear movement of a carriage having a printer head attached thereto in a direction perpendicular to the paper feed direction.

In the figure, the toothed belt A is stretched between a driving side timing pulley 7 and a driven side timing pulley 8 which are arranged in parallel at a predetermined interval and have the same pitch circle diameter. On the outer circumference of the timing pulleys 7 and 8,
Semicircular pin receiving groove for allowing engagement with the drive pin 3
Set 7a and 8a to the specified positions by taking their engagement timing into consideration.
It is provided one by one. And both timing pulleys 7,8
Are rotatably supported by respective printer main bodies (not shown), and the rotational force of the motor 10 can be transmitted to the timing pulley 7 on the driving side through the reduction gear mechanism 9.

The reduction gear mechanism 9 includes a pulley-side gear 9a fixed to the rotation shaft of the timing pulley 7, a motor-side gear 9b fixed to the rotation shaft of the motor 10, and both gears 9a and 9b that are individually meshed with each other and It is composed of two intermediate gears 9c and 9d which are integrated. A rotary plate 12 having a plurality of slits 11 around the rotary shaft of the motor 10 is attached to the motor-side gear 9b, and a photosensor 13 is provided on the rotary plate 12 so as to face the rotary plate 12. And photo sensor 13
It constitutes 10 rpm detectors.

The carriage 14 has a rectangular parallelepiped shape, and has a through hole 15 penetrating the thick portion in the width direction at the center in the longitudinal direction, and the toothed belt A is inserted into the through hole 15.
The carriage 14 is provided with elongated holes 16 extending in the longitudinal direction thereof and engaged with the drive pins 3 of the toothed belt A at upper and lower thick portions of the through hole 15 in association with the through hole 15. A notch 17 that is continuous in the width direction and through which the rotation shafts of the timing pulleys 7 and 8 pass is provided in the thick portion below the through hole 15.

Further, 18 and 19 are guide rails arranged on both outer sides of the toothed belt A in parallel with the straight running portions of the toothed belt A, and the first guide rail 18 is a transparent rail provided on the carriage 14. The second guide rail 19 is slidably inserted in the hole 14a, and is slidably engaged with a guide groove 14b also provided in the carriage 14.

20 is a serial printer head mounted on the upper surface of the carriage 14, 21 is an ink ribbon facing the front, 22
Is a platen disposed on the front surface of the serial printer head, and the serial printer head 20 prints on the paper 23 supplied on the surface of the platen 22.

Then, the rotational force of the motor 10 is transmitted to the timing pulley 7 on the driving side via the reduction gear mechanism 9, and the rotational force causes the toothed belt A to travel in the direction of the arrow Y. By the moving force of the drive pin 3, the carriage 14 in which the drive pin 3 engages with the elongated hole 16 moves in the same direction as the moving direction of the drive pin 3. Then, the drive pin 3 approaches the line head (or line end) portion (FIG. 5 (a)), and further moves, so that the drive pin 3 moves toward the drive side timing pulley 7 (see FIG. 5 (b)). Or timing pulley 8 on the driven side
When it comes into contact with the drive pin 3, the half surface of the drive pin 3 is pin receiving groove 7a.
(Or 8a) go in.

Subsequently, the drive pin 3 and the drive-side timing pulley 7 integrally rotate at a predetermined angle (180 degrees) (Fig. 5 (c)), and then they are separated as shown in Fig. 5 (d).
The drive pin 3 moves to the line end (or line head) side.

In this case, since the toothed belt A is formed by aligning the axis O of the drive pin 3 with the pitch line L of the belt body 1, the reaction force received by the drive pin 3 from the carriage 14 is a toothed belt. Acts on the center of A. Therefore, since the moment due to the reaction force from the carriage 14 does not act on the toothed belt A, the toothed belt A does not vibrate. Therefore,
Since the carriage 14 is not affected by the vibration of the toothed belt A, the carriage 14 does not vibrate.
Therefore, it is possible to prevent the dot pitch from being disturbed due to the printing operation of the printer head 20, which has been remarkable in the related art, especially at the line ends or line heads, and thereby to print a neat character on the paper 23.

[Effects of the Invention] As described above, according to the present invention, the pitch line of the belt main body and the axial center line of the drive pin are made coincident with each other, and the drive pin is two plate-shaped pieces and two pieces. The drive pin can be manufactured at a low cost with a simple structure because it is configured with the shaft body, and a moment is generated in the mounting portion of the drive pin of the belt body even when the drive force acts on the drive pin. Therefore, the driving force of the belt main body can be transmitted to the carriage or the like via the drive pin without causing vibration or the like due to the moment.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is an exploded perspective view of a belt body and a plate-like piece, FIG. 3 is an exploded perspective view of a shaft body, and FIG. FIGS. 5A to 5D are explanatory diagrams showing an example of the usage state, respectively, for explaining the operation. 1: Belt body, 2: Tooth 3: Drive pin, 4: First plate-shaped piece 4a: Bulging part, 4b: Engaging groove 4c: Square window, 4d: Positioning hole 5: Second plate-shaped piece, 5a: Protrusion 6: Shaft, 6a: Square hole A: Toothed belt L: Pitch line of belt body O: Pin axis line

Claims (1)

[Scope of utility model registration request] 1. A toothed belt in which a large number of teeth are provided at equal intervals on an endlessly continuous belt main body, and drive pins whose end portions project from both sides in the width direction of the belt main body are provided. The pin includes a first plate-shaped piece having a square window that engages with the teeth, a second plate-shaped piece that holds the belt main body between the first plate-shaped piece, and the first plate-shaped piece. And two shaft bodies provided with square holes that are fitted to both ends of the first and second plate-like pieces and with the center lines of the shaft bodies aligned with the pitch lines of the belt body. Toothed belt to be.