JPS60205872A - Carriage device - Google Patents

Abstract

PURPOSE:To always attain the accurate position control of a carriage by winding an energizing member of a small spring constant in the opposite direction to a belt which is wound round a pulley that drives the carriage. CONSTITUTION:A belt 12 having its end fixed to a carriage 11 at one side and the other end fixed to a pulley 9 is wound round the pulley 9 which drives the carriage 11. A coil spring 17 having a small spring constant is wound at the center of the pulley in the direction opposite to the winding direction of the belt 12. thus the position control of the carriage is secured with high accuracy regardless of the present position of the carriage 11 by combining the belt 12 which always keeps the length of the spring 17 at a fixed level as well as the fixed tension with no extension and the spring 17 of a small spring constant.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a carriage device, and more particularly to a head positioning mechanism for a floppy disk device or the like.

Conventional Technical Director Normally, a large number of tracks are formed on a floppy disk at a pitch of about 0.5 mm. Therefore, a high degree of precision is required in controlling the operation of the read/write head. For this reason, the carriage device that holds the head is configured as shown in FIG. 1, for example. In this case, by rotating the pulley 1 connected to a motor etc. in the clockwise direction in the figure, the carriage 2 slidably installed on the guide bar 3 can be moved to the left in the figure via the belt 4. You can move it to the right by rotating it counterclockwise.

Here, in order to accurately control the position of the carriage 2,
First, it is necessary to prevent the belt 4 from loosening. For this reason, a certain amount of tension is applied to the belt 4 and its both ends are fixed to the carriage 2, but there is a problem in that the tension changes during assembly due to variations in tension or shrinkage due to changes in belt temperature.

Therefore, as shown in Figure 1, one end of the belt 4 is connected to a plate spring 5.
A method of fixing to the carriage 2 via an elastic member such as the like is often used. This absorbs the above-mentioned variation in tension.

However, since leaf springs have a relatively large spring constant, it is not only difficult to set the belt tension constant, but also difficult to accurately hold the belt in a constant manner, making it difficult to control the position with high precision. It cannot be said that it is suitable as a belt holder for a carriage device which requires the following.

(2) The present invention has been made in view of the above points, and it is an object of the present invention to provide a carriage device that is easy to manufacture, inexpensive, and capable of stable and accurate position control at all times.

W Bottom The configuration of the present invention will be described in detail below based on specific examples.

FIG. 2 is a perspective view showing a read/write head carriage device in a floppy disk device as an embodiment of the present invention. In FIG. 2, a pulley 9 is fixed to a shaft 8 of a motor 7. As shown in FIG. 3, the pulley 9 has a recess 9a formed in the center of its circumferential surface, and a coil spring 17, which will be described later, is wound around the recess 9a. Further, a belt 12 is wound around the other circumferential surface except for the recess 9a. The depth D of this recess 9a is
The cross-sectional center O of the coil spring 17 to be wound and the cross-sectional center 02 of the belt 12 are positioned at approximately the same level with respect to the rotation center of the pulley 9, that is, the coil spring 1
The curvatures of belt 7 and belt 12 are set to be equal.

Returning to FIG. 2, the carriage 11 holding the read/write head (not shown) has two guide bars 1 in this example.
0.10 and is slidably supported. guide bar 10
The extending direction of the motor 7 is set to be perpendicular to the shaft 8 of the motor 7.

Thus, the side surface 11 of the carriage 11 facing the pulley 9
A is formed in a stepped shape, and the image portion on one end side and the boo U9 are connected by a belt 12. belt 12
A hollow portion 12a is formed along the longitudinal direction. The width W of this hollow portion 12a is the width W of the coil spring 1
7 is ensured to be large enough to be inserted therethrough. Both ends of the belt 12 are fixed to one end of the side surface 11a and the circumferential surface of the pulley 9 by screws 14 and 16.16, respectively, via presser plates 13.15. In this case, since the position of the carriage 11 is determined by the belt 12, it is required to select a material for the belt 12, such as stainless steel, whose length does not substantially change even with changes in the temperature of the atmosphere.

The other end of the side surface 11a of the carriage 11 and the pulley 9 are connected by a coil spring 17. in this case,
The coil spring 17 is wound around the pulley 9 in the opposite direction to the belt 12. Therefore, by appropriately rotating the pulley 9 back and forth, the carriage 11 can be moved linearly back and forth along the guide bar 10 and its position can be controlled. Here, both ends of the coil spring 17 are connected to a protrusion 18 erected at the end of the concave portion of the side surface 11a, and holes 18a, 15a formed in a presser plate 15 fixed to the circumferential surface of the pulley 9. It is locked to.

In this respect, assembly is easier than when fixing with screws or the like. Further, at a portion where the coil spring 17 and the belt 12 intersect, the coil spring 17 is inserted into the hollow portion 12a of the belt 12.

Thereby, both can be wound around the pulley 9 without overlapping. Therefore, in combination with setting the respective curvatures of the belt 12 and the coil spring 17 to be the same when they are wound together as described above, the length of the coil spring 17 is always kept constant regardless of the position of the carriage, and a constant tension can be maintained. can be maintained, and the position of the carriage 11 can be accurately controlled.

Furthermore, by using a coil spring as a belt, tension due to its elastic force can be applied along the guide bar 10. As a result, the carriage 11
The frictional force between the guide bar 10 and the guide bar 10 can be minimized, and the position of the carriage 11 can be controlled more accurately. Furthermore, since the coil spring 17 can essentially have a small spring constant, variations in tension due to assembly conditions and component characteristics can be suppressed. Therefore, it is possible to stably manufacture a carriage device having accurate position control performance. In addition, since the belt 12 is required to be made of a material that is flexible and does not stretch, it is naturally expensive, but in this example, the coil spring 17 is used as a part of the belt, which reduces costs accordingly. Contribute.

Next, some other embodiments of the present invention will be described. Note that the same components as those in the above embodiment are given the same reference numerals, and the explanation thereof will be omitted. The embodiment shown in FIGS. 4a and 4b is similar to the coil spring 17 of the above embodiment.
Instead, a narrow belt 21 made of a material with a smaller spring constant than the belt 12 is used. As the material of the narrow belt 21, rubber, plastic, or metal such as copper or stainless steel can be used. The thickness thereof is set to be thinner than that of the belt 12, and the width thereof is set to be small enough to be inserted into the hollow portion 12a.

Both ends of the narrow belt 21 are respectively identified by screws 16.23 via a presser plate 15.22 to the peripheral surface of the boot IJ 20 and one end of the white portion at both ends of the carriage side surface 11a'.

With the above configuration, the narrow belt 21 having more elasticity can apply the necessary tension to the belt 12, and the position of the carriage 11 can be accurately controlled as in the above embodiment. Note that in this example, there is no need to form a recess on the circumferential surface of the pulley 20.

In the embodiment shown in FIG. 5, a step is provided at the end of the circumferential surface of the boot IJ 26, and a coil spring 17 is wound around this lower step surface 26a. And the upper surface 26b
A belt 25 is wound around the belt.

Therefore, in this example, there is no need to form a hollow part in the belt 25, which contributes to reducing the cost of the belt.

Further, both ends of the coil spring 17 are connected to a protrusion 18 and a hifuri 26, respectively, which are provided upright at one end of the carriage side surface ILa.
It is secured to a pin 27 that is erected on the lower peripheral surface of the holder, and this point assembly is easy.

In the embodiment shown in FIG.
a and a narrow part 28b, and a hollow part 28 is formed in the wide part 28a.
c is provided. Thereby, the pulley 26 can be rotated one or more times to accurately control the position of the carriage 11 over a longer stroke.

Effects As detailed above, according to the present invention, by combining a non-stretchable belt member and a biasing member having a smaller spring constant, a carriage device having an extremely accurate position control function can be manufactured at a low cost. I can do it. In particular, by using a coil spring with a small spring constant as the biasing member, a highly accurate carriage device can be stably obtained. It should be noted that the present invention should not be limited to the specific embodiments described above, and it goes without saying that various modifications can be made within the technical scope of the present invention.

For example, the present carriage device can be applied not only to read/write heads of floppy disks, but also to various measuring devices that require accurate positioning functions.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing a conventional carriage device, and Figure 2 is a schematic diagram showing a conventional carriage device.
3 and 3 are a schematic diagram and an explanatory diagram showing one embodiment of the present invention, respectively, FIGS. 4a and 4b are an elevational view and a perspective view showing another embodiment of the present invention, and FIG. Figures 6 through 6 are a schematic diagram and a plan view, respectively, showing still other embodiments of the present invention. (Explanation of symbols) 1.9, 20, 26; pulley 2.11. ; Carriage 3.10; Guide bar 4.12, 25, 28; Belt 17; Coil spring 21; Narrow belt Patent applicant Ricoh Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 40 Figure 4b

Claims (1)

[Claims] 1. In a carriage device that performs reciprocating linear motion, a pulley is fixed to a drive shaft connected to a drive means, and a guide member extends linearly in a direction perpendicular to the drive shaft. a carriage installed slidably; a belt member having one end fixed to the carriage and the other end fixed to the pulley so as to be wound thereon; and one end fixed to the carriage at a fixed position of the belt member. is fixed at the opposite position via the pulley, and the other end is fixed to the pulley so that it can be wound in a direction opposite to the winding direction of the belt member, and has a smaller spring constant than the belt member. A carriage device comprising a biasing member. 2. The carriage device according to item 1 above, wherein the biasing member is a coil spring. 3. In the above item 1, when the biasing member is wound in a recess provided along the curved surface of the pulley, and each curvature of the belt member and the biasing member is wound around the pulley, Carriage device characterized by equality. 4. In the above item 1, the belt member is composed of a narrow part and a wide part, and the wide part has a hollow part capable of accommodating the narrow part, and the belt member has a peripheral surface of the pulley. A carriage device characterized in that the carriage device is divided into a part to be wrapped around and a part to be wrapped around the urging member.