JPS62124972A - Feeder for printing head - Google Patents

Abstract

PURPOSE:To obtain a printing head feeder light in weight and low in cost, by providing a support means for supporting the lower surface of an intermediate part of a guide shaft which supports a lower surface of a carriage. CONSTITUTION:Guide shafts 4, 5 are fitted, in parallel to each other, to side plates 2, 3 of a machine body frame 1 of a printer. The guide shaft 4 is passed through a through-hole 7a of a carriage 7 for feeding a printing head 6. A permanent magnet 8 is fixed to a rear end part 7b of the carriage 7 so that it can be slidden in contact with an upper surface of the guide shaft 5. An intermediate part of the guide shaft 5 is supported by a support means 9, whereby it is prevented from being flexed in the direction of gravity. Namely, a supporting plate 11 is slidably connected to a support plate 10 erected on the frame 1, by a screw 12. In addition, an eccentric cam 14 rotatably fitted to the supporting plate 11 by a screw 15 makes contact with an upper end face of the support plate 10 to position the supporting plate 11. Since the guide shaft 5 is supported by a spring member 13 through the supporting plate 11, the printing head 6 can be stably slidden.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a print head conveyance device.

(Prior art) In conventional print head conveyance devices used in printing devices, etc., a carriage carrying a print head is conveyed while being guided by two guide shafts that are supported on support plates on both sides parallel to a platen. be done.

The carriage has a hole in front of it through which one of the guide shafts located on the platen side passes, and a hole in the rear through which the other guide shaft located parallel to the one guide shaft passes or a hole in the other guide shaft. There is a U-shaped groove that pinches the shaft from above and below to prevent it from rotating. Since the force applied to the carriage changes depending on the number of dots to be printed, the carriage and both guide shafts must have sufficient rigidity to withstand this force. Particularly in printing devices that perform high-speed printing or printing devices that have a large span between supporting plates on both sides, a thick guide shaft is usually used to provide sufficient rigidity.

(Problems to be Solved by the Invention) As the guide shaft becomes thicker, the weight of the device increases accordingly, resulting in higher costs. Furthermore, if the rigidity is insufficient or if the intermediate portion is deflected due to impact, etc., the printing result will be wavy, the dots will be uneven in the horizontal direction, and the printing quality will deteriorate.

Therefore, the purpose of the present invention is to improve stability in the direction of gravity even if the guide shaft is made thinner to some extent, improve printing quality, reduce weight and reduce cost even for printing devices that perform high-speed printing or printing devices with large spans. Our company also provides inexpensive print head transport equipment.

(Means for Solving the Problems) In the print head conveyance device of the present invention, a carriage on which the print head is mounted is slidably supported by two guide shafts, and one of the guide shafts is attached to the carriage. It passes through one end, the other is made of a magnetic material, and is provided to receive the lower surface of the other end of the carriage. A permanent magnet is provided at the other end of the carriage to magnetically attract the other end to the other guide shaft. A support means for supporting the lower surface of the other guide shaft is provided at the intermediate portion of the other guide shaft.

(Function) In the carriage on which the print head is mounted, one guide shaft passes through a through hole provided at one end, and a permanent magnet is provided at the other end, and the other end is formed of a magnetic material. It is magnetically attracted to the other guide shaft and is slid along both guide shafts. Further, a support means provided at an intermediate portion of the other guide shaft keeps the other guide shaft horizontal.

(Example) Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, a mechanical frame 1 of a printer has side plates 2 and 3 erected at a predetermined interval. Side plates 2, 3
A guide shaft 4 and a guide shaft 5 are installed in parallel. The carriage 7 on which the print head 6 is mounted and which transports the print head is provided with a through hole 7a at its front end (on the right side) as shown in the third figure, through which the guide shaft 4 passes. The rear end 7b of the carriage 7 is able to freely slide in contact with the upper surface of the guide shaft 5 made of a magnetic material. A groove is provided in the rear end portion 7b, and a permanent magnet 8 that magnetically attracts the guide shaft 5 is inserted into this groove and fixed thereto. The intermediate portion of the guide shaft 5 is supported by support means 9 to prevent deflection in the direction of gravity. That is, the supporting means 9
As shown in FIGS. 1 to 4, a support plate 10 is provided upright on the machine body frame 1, and a support plate 11 is swingably connected to the support plate 10 by screws 12. The support plate 11 is pulled by a spring member 13 and comes into elastic contact with the lower surface of the guide shaft 5. Since the upper end of the support plate 11 is layered in an L-shape, its upper surface 11a is in stable elastic contact with the guide shaft 5. Further, an eccentric cam 14 is rotatably attached to the support plate 11 with a screw 15, and the cam surface of the eccentric cam 14 abuts the upper end surface of the support plate 10 to position the support plate 11.

During assembly, the guide shaft 4 is passed through the mounting hole 7a of the carriage 7, and the guide shaft 4.5 is supported by the side plates 2.3. The rear end portion 7b of the carriage 7 is brought into contact with the upper surface of the guide shaft 5. After confirming that the guide shaft 5 is in a horizontal state, the upper surface 11a of the support plate 11 is brought into elastic contact with the lower surface of the guide shaft 5 by the spring force of the spring member 13, and in this state, the eccentric cam 1 is
4 is rotated and adjusted so that it abuts on the upper end surface of the support plate 10, and the eccentric cam 14 is fixed with a screw 15.

A carriage 7 carrying a print head 6 is attached to guide shafts 4 and 5.
When the carriage is conveyed from side to side and printed, the rear end 7b of the carriage slides on the upper surface of the guide shaft 5, so it is not obstructed by the support means 9, and the guide shaft 5 is moved along the support plate 11. Since the print head 6 is supported by the spring force of the spring member 13 via the print head 6, it does not bend in the direction of gravity, and the print head 6 can slide stably. Therefore, printing is performed with dots that are correctly aligned laterally. When some external force that exceeds the spring force of the spring member 13 is applied and the guide shaft 5 is bent in the direction of gravity, the support plate 11 resists the spring force of the spring member 13 and swings clockwise around the screw 12 in the clockwise direction in FIG. oscillating (dashed line in Figure 2),
Although deflection of the guide shaft 5 is allowed, as soon as the external force is removed, the support plate 11 swings counterclockwise due to the spring force of the spring member 13 and returns to its original position, and the upper surface 11a of the support plate 11 is The guide shaft 5 is lifted to its original position and its deflection is removed.

Note that if the distance between the machine body frame 1 and the guide shaft 5 is set strictly, the support means 9 may be constructed of one member and attached to the machine body frame. Further, in FIG. 1, 15 is a platen, and 16 is a paper feeding tractor.

(Effects of the Invention) In the present invention having the above configuration, the middle part of the other guide shaft is supported by the support means, so that it can be used even in printing devices that perform high-speed printing or printing devices with a large span between both side plates. Deflection of the guide shaft can be prevented, the stability of the print head in the direction of gravity is improved, printing quality can be improved, and the weight of the device can be reduced. In addition, by configuring the support means with a support plate, a support plate, a spring member, etc., it is possible to support the other guide shaft in a horizontal state, adapting to minute changes in manufacturing intervals, and thereby reducing external forces. It is possible to immediately restore the deflection of the other guide shaft caused by this, which helps stabilize printing quality.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is an enlarged front view of main parts, Fig. 3 is a sectional view taken along the line ■-■ in Fig. 2, and Fig. 4 is a part of Fig. 2. FIG. DESCRIPTION OF SYMBOLS 1... Machine frame, 4... One guide shaft, 5... Other guide shaft, 6... Print head, 7... Carriage, 8... Magnetic attraction means, 9. ... Support means, 10... Support plate, 11... Support plate, 13... Spring member, 14... Eccentric cam. that's all

Claims (1)

[Scope of Claims] 1. It includes a carriage on which a print head is mounted and two guide shafts that slidably support this carriage, and one of the carriage shafts passes through one end of the carriage. and the other end is provided to receive the lower surface of the other end of the carriage, and a permanent magnet is provided at the other end of the carriage to magnetically attract the other end to the other guide shaft. 1. A print head conveyance device, characterized in that a support means is provided at an intermediate portion of the other guide shaft to support a lower surface of the other guide shaft. 2. In claim 1, the support means includes a support plate erected on the machine frame, a support plate swingably connected to the support plate, and a support plate connected to the second guide shaft. and an eccentric cam which is rotatably attached to the support plate and whose cam surface abuts the upper end surface of the support plate to position the support plate. A transport device for the print head.