JPS6259063A - Space mechanism in printer - Google Patents

Abstract

PURPOSE:To simplify the construction and reduce the number of component parts to facilitate assembly, by a method wherein a pressing cam and an engaging member are rotatably mounted on a side frame and a follower pulley is energized in the direction where a deflection alleviating member is mounted. CONSTITUTION:A pressing cam 34 having a cam face 36 and an engaging member 27 are rotatably mounted on a side frame 14. At the outside of the side frame 14, the engaging member 27 supporting a pulley shaft 33 is energized in the direction where a deflection alleviating member is mounted by being pressed by the pressing cam 34. Then, the pressing cam 34 is engaged with the energized engaging member 27 at the cam face thereof 36 to be held. In this manner, the tension of the deflection alleviating member can be constantly maintained, which realizes reduction of the number of the component parts to enhance the assembly property.

Description

[Detailed Description of the Invention] This invention is particularly applicable to printing devices such as printers, plotters, and typewriters in which the rotation of a motor is transmitted to a carriage via a flexible mediating member such as a wire belt. , it can be applied to a serial printing device that prints while moving the carriage along a platen. In particular, the present invention relates to a spacing mechanism in such a printing device.

BACKGROUND OF THE INVENTION In general, the spacing mechanism of this type of printing device always keeps the deflection mediating member under tension in order to ensure the accuracy of the stop position on the carriage. However, when repeated stress is frequently applied to the bending mediating member as the carriage moves and stops, the bending mediating member elongates over time.
This causes the carriage to stop at an incorrect position, resulting in uneven printing and deterioration in printing quality.

Conventionally, in order to solve this problem, for example, as shown in FIG. 2 supported by stays (4) and tension springs (5)
The pressing cam (7) is rotated counterclockwise in the figure around the mounting shaft (6) by the pulley shaft (2).
) to keep the belt (3) under tension at all times. In addition, as another conventional space mechanism, as shown in Fig. 6, the pulley shaft (2) of the driven pulley (1) is supported by a lever (8), and the lever is centered around its mounting shaft (9). It is rotatably attached to the stay (4) and the bent part (10a
) by the compression spring (11) arranged between the pressing cam (
12) between the pulley shaft (2) and the rising portion (tab) of the side frame (10), and
) in the direction in which the belt (3) is stretched to maintain the belt in tension.

However, the conventional structures described above require mounting shafts (6) and (9) to rotatably support the pressing cam (7) and lever (8), respectively.
Since a tension spring (5) and a compression spring (11) must be used to bias the pressure cams (7) and (12), respectively, the number of parts increases, resulting in high costs and a complicated structure. The disadvantage was that it took time and effort to assemble.

Purpose Therefore, the present invention provides a printing device in which a carriage is moved using a bending member such as a wire or a belt.
The purpose of the present invention is to make it possible to keep a bending mediating member in a tensioned state at all times with a simple structure, reduce the number of parts, reduce costs, and improve assemblability.

Configuration The invention of So-1'1,- is such that a bending mediating member such as a wire or a belt (19) is connected to a driving pulley (20) and a driven pulley (20).
21) The pulley shaft (33) of the driven pulley (21) is movable in the spanning direction of the bending mediating member, and the pulley shaft A pressing cam (34) is pressed against (33), and the bending mediating member is driven by a space motor (22) via the drive pulley (20) to move the carriage (I8).
In the space mechanism of the printing device that moves the press cam (34), the press cam (34) is provided with a cam surface (36), and the press cam (34) and the engagement member (27) are rotatably attached to the side frame (14). , the engaging member (27) supports the pulley shaft (33) on the outside of the side frame, and the pressing cam (34) is attached to the engaging member (z7).
) is pressed against the engaging member (27) in the direction in which the bending mediating member is stretched, and in this biased state, the cam surface (36) of the pressing cam (34) is pressed against the engaging member (27). 2
7) to hold the pressing cam (34).

Hereinafter, the present invention will be described in detail based on an embodiment of the present invention shown in the drawings. Fig. 4 shows a serial printer equipped with a spacing mechanism according to the present invention, and the cylinder number (13) in Fig. 1 is a platen. The platen (13) has both ends attached to the left and right side frames (
Supported by 14) and (15). A guide shaft (16) and a rear steering wheel (17) are also spanned over these side frames (14) and (15), and each platen (1
Parallel to 3). The carriage (18) is supported by the guide shaft (16) and rear steer (17).

Both ends of the belt (19) are attached to the carriage (18). The belt (19) is passed around the driving pulley (20) and the driven pulley (21). The drive pulley (20) is driven by a space motor (
22) on the motor shaft (22a) of the motor (22).
2), the belt (19) is moved, and the carriage (18) is guided by the guide shaft (16) so that it can move appropriately along the platen (13). At this time, a print head mounted on the carriage (18) sequentially prints on the sheets set on the platen (13).

1 to 3 show the structure of the driven side of the space mechanism in the serial printer shown in FIG. 4. The left side frame indicated by the symbol (14) in the figure has an opening (23
) open. The opening (23) has notches (24), (25), and (26) on both left and right sides and above, respectively, as shown in Figure 1.
will be established. The driven pulley (21) is held by an engagement member (27) on the outside of the side frame (14) through the opening (23) from inside the side frame (14). The engaging member (27) is formed by bending the plate-like member into a U-shape as a whole and forming a fitting convex portion (28) extending in an L shape from the base end.
) are formed in parallel. Then, this fitting convex portion (28)
Locking steps (29) and (29) are formed on the lower side of (28). An engagement hole (31) is provided in the base (30) of the engagement member (27).
)・(31) are opened in parallel. On the distal end side of the engagement member (27), there is a latch convex portion (3) bent in a U-shape to protrude.
2) Form. Thus, the engaging member (27) has its fitting convex portions (28) and (28) cut out (24), respectively.
- Fit into (25) and rotatably attach to the side frame (14) using the locking stages (29) and (29) as fulcrums. and.

Both ends of the pulley shaft (33) of the driven pulley (21) are hooked into the engagement holes (31) and (31) of the engagement member (27).
The driven pulley (21) is connected to the belt (1) by the engaging member (27).
9) It is held so that it can be moved in the hanging direction (horizontal direction in the figure).

A fitting convex portion (35) provided at one end of the pressing cam (34) is fitted into the notch (26) of the side frame (14).

The pressing cam (34) is rotatably attached to the side frame (14) using the stepped portion (35a) on the fitting convex portion (35) as a fulcrum. The pressing cam (34) uses a plate-like member and has a cam surface (36) on one side of the engaging member (27).
), and a flat portion (37) is formed on the cam surface (36).

Now, as shown by the arrow in Fig. 2, the pressing cam (34
) and rotate it counterclockwise in the figure using the step (35a) on the fitting convex part (35) as a fulcrum, so that the cam surface (37) of the plate cam part (36) aligns with the engaging member (27). Latch protrusion (3
2) Press it against. Then, the engaging member (27) swings slightly outward (to the left in the figure) on the side of the latching protrusion (32) at its tip, but at the same time, the engaging protrusions (2, 8) and (28) swing inward. (to the right in the figure), the locking steps (29) and (29) abut against the outer surface of the side frame (14), and then, as shown in FIG. Step (2
9) While rotating counterclockwise around (29) as a fulcrum, push the driven pulley (21) in the direction in which the belt (19) is stretched (to the left in the figure) and gradually apply tension to the belt (19). Try to keep them in a tense state. Then, after rotating the pressing cam (34), the flat part (3
7) is latched to the latching convex portion (32) of the engaging member (27), and the belt (19) is always maintained in a tensioned state. Therefore, the belt (
19), and the carriage (18) feeds the guide shaft (
16) to be accurately positioned.

In the illustrated embodiment, the belt (19) is used as the bending mediating member, but the belt (19) is used as the bending mediating member.
19) but may also be a wire or the like.

Effects According to the present invention, a bending medium member such as a wire belt is stretched between the left and right pulleys, the bending medium member is driven by a motor to move a carriage, and the print head mounted on the carriage sequentially prints images. In a printing device that performs printing, the pressing cam and the engaging member are rotatably attached to the side frame without using a mounting shaft or a spring, and the driven pulley is biased in the direction in which the bending mediating member is spanned. The overall space and mechanical structure are simplified, the number of parts is reduced, costs are reduced, and assembly is facilitated.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of the driven side of the space mechanism of the serial printer shown in FIG. 4, and FIGS. 2 and 3 are front views illustrating the mechanism for applying tension to the belt of the space mechanism shown in FIG. 1. It is. FIG. 4 is a schematic plan view of a serial printer equipped with a spacing mechanism according to the present invention. FIGS. 5 and 6 are plan views showing the spacing mechanism of a conventional printing device, respectively.

Claims (1)

[Claims] Suspending the bending mediating member between the driving pulley and the driven pulley,
The pulley shaft of the driven pulley is movable in the direction in which the bending mediating member is spanned, and a pressing cam is pressed against the pulley shaft so that the bending mediating member is always in a tensioned state;
In the spacing mechanism of the printing device in which the bending mediating member is driven by a space motor via the drive pulley to move the carriage, the pressing cam is provided with a cam surface, and the pressing cam and the engaging member are rotatable. attached to a side frame, the engagement member supports the pulley shaft on the outside of the side frame, and the pressing cam is pressed against the engagement member to move the engagement member in the direction in which the bending mediating member is spanned. A space mechanism for a printing device, wherein the pressing cam is held by holding the cam surface of the pressing cam on the engaging member in this biased state.