JPH07117135B2 - Wire rope stretch absorber - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wire rope stretch absorber in a device driven via a wire rope.

2. Description of the Related Art Conventionally, in a driving device for a mirror traveling body such as an image reading device and an electrophotographic copying machine, or a driving device for a carriage of a print head such as a printer, the apparatus is driven by a pulley and a driving source provided on the machine frame and the traveling body. A wire rope driving device is widely used which is reciprocally driven by a wire rope which is hung around a driving pulley and whose both ends are respectively connected to the machine frame or the wire rope by the wire rope. The reason why such a wire rope driving device is adopted is that it has a feature that the moving mass can be reduced and the arrangement thereof is relatively free.

However, the problem with the wire rope drive device is that the wire rope stretches over time, and if this stretch is not absorbed, the tension decreases, which causes slack to prevent the traveling body from traveling accurately. It may be said.

As a device for absorbing the elongation of such a wire rope, there is a device described in JP-A-62-101171, as shown in FIG. That is, one end of each of the wire ropes 30 and 31 is fixed to the machine frame and the second traveling body 32. The wire ropes 30 and 31 are attached to the machine frame and the second traveling body 32 so that the wire ropes 30 and 31 are allowed to rotate only in the direction in which the tensile force of the wire ropes 30 and 31 increases. After winding one or more turns around the wires 36 and 36 as shown in FIG. 8, the other ends of the wire ropes 30 and 31 are
It is locked to the machine frame and the locking points 39 and 40 on the second traveling body 32 via the tension springs 37 and 38.

According to such a configuration, the rotary one-way clutch 35, 36
The winding direction of the wire rope around the outer circumference of the wire rope is the direction in which the outer rings of the rotary one-way clutches 35 and 36 are allowed to rotate only in the direction in which the tensile force of the wire rope increases, so When the wire ropes 30 and 31 are extended, the wire ropes 30 and 31 are pulled by the tension springs 37 and 38 and
Rotary one-way clutches 35, 36 in the direction indicated by arrow D in the figure
Rotate and move with the outer ring. Further, even if the wire ropes 30, 31 are pulled in opposite directions due to the static inertia of the first and second traveling bodies 32 at the time of starting, or the first and second traveling bodies 32 try to vibrate at the time of stop, the wire ropes 30, Since the 31 does not return due to the action of the rotary one-way clutches 35 and 36,
Also, the second traveling body 32 moves in the same amount in synchronization with the drive pulley 43 even at the time of starting, and is prevented from vibrating even at the time of stopping.

However, in the case of the above configuration, the ratio of the diameter r of the wire rope shown in FIG. 8 to the outer diameter R of the rotary type one-way clutch around which these wire ropes are wound is limited to about 1:10 to 1:40. There is. In other words, when the wire rope exceeds the range, when the first and second traveling bodies 32 are started and stopped, or when a strong tensile force is applied to the wire rope, the outer circumference of the wire rope and the rotary one-way clutch. There is a problem that slippage occurs between the wire and the wire rope and it becomes impossible to absorb the elongation of the wire rope.

In view of such problems, the present invention aims to provide a wire rope elongation absorber capable of reliably absorbing the elongation of the wire rope even when a strong tensile force is applied to the wire rope. And

Configuration According to a first aspect of the invention, a traveling body that can reciprocate along a guide member fixed to a machine frame is provided, and the traveling frame is hooked on a pulley provided on the machine frame and the traveling body and a drive pulley driven by a drive source. In the wire rope drive device which is passed over and reciprocally drives the traveling body through the wire ropes whose both ends are respectively locked to the machine casing or the traveling body, the wire rope driving device is fixed to the machine casing or the traveling body. The inner ring is fixed to the cylindrical shaft to fix the rotary one-way clutch, and the plate to which one end of the wire rope is locked is fixed to the outer ring of the rotary one-way clutch, and the wire rope is stretched. A tension spring is bridged between the plate and the machine frame or the traveling body so as to urge the plate in the direction of rotation.

A second aspect of the invention is to provide a traveling body that can reciprocate along a guide member fixed to the machine frame, and hang it around a pulley provided on the machine frame and the traveling body and a drive pulley driven by a drive source. In the wire rope driving device configured to reciprocally drive the traveling body via the wire ropes whose both ends are respectively locked to the machine casing or the traveling body, an outer ring is fixed to the machine casing or the traveling body. A rotary type one-way clutch is provided, a plate fixed at one end of the wire rope is fixed to a shaft fixed to the inner ring of the rotary type one-way clutch, and the plate is mounted in the direction in which the wire rope is stretched. It is characterized in that a tension spring is bridged between the plate and the machine frame or the traveling body so as to be biased.

An embodiment of the present invention will be described below with reference to FIGS. First, FIG. 1 shows a schematic configuration of an example of an image reading apparatus which is one of the devices to which the present invention is applied. In the figure, an original 2 placed on an original glass 1
Is illuminated by the lamp 3, and the reflected light is reflected by the first mirror 4
The light is reflected by the second mirror 5 and the third mirror 6, and is projected and imaged on the image sensor 8 by the lens 7. Lamp 3
And the first mirror 4 are integrally carried by a first traveling body (not shown in FIG. 1), move in the direction of arrow A, and move to the second mirror 5
The third mirror 6 is integrally carried by the second traveling body (not shown in FIG. 1) and moves in the same direction synchronously at half the speed of the first traveling body to perform sub-scanning. Be seen. The main scanning is performed by the self-scanning of the image sensor 8, and the original 2 is two-dimensionally scanned by these and converted into an electric signal and output. In FIG. 1, 3 ', 4', 5'and 6'shown by chain lines are
The positions of the lamp 3, the first mirror 4, the second mirror 5, and the third mirror 6 when the sub-scan is completed are shown.

As a wire rope drive device in which the first traveling body and the second traveling body are moved at a speed of 2: 1 in synchronization with each other, a wire rope driven by a drive source is fixed to the first traveling body. At the same time, a wire rope drive device is widely used, which is wound around a drive pulley axially supported by a second traveling body and is moved at a speed of 2: 1 in synchronization with the principle of a moving pulley.

The one shown in FIG. 2 is an example thereof, and the wire rope stretching and absorbing device, which is a characteristic part of the present invention, includes the main parts 10 and 11.
It is provided in. First, FIG. 4 shows the structure of the main part 10 of the wire rope elongation absorber. In FIG. 4 (a), a cylindrical shaft 16 is fixedly mounted on the second traveling body 15, the inner ring of the rotary one-way clutch 17 is fitted to the shaft 16, and the outer ring is a plate.
It is fitted and fixed to the sleeve 18 fixed to 19.
At one end of the plate 19 is a wire rope with a locking point 20.
12 is locked, and the plate 19 is urged between the locking point 22 at the other end of the plate 19 and the locking point 23 of the second traveling body 15 in the direction in which tension acts on the wire rope 12. Thus, the tension spring 21 is locked. 4 (b), the shaft 16, the rotary one-way clutch 17, the sleeve 18, the plate 19, and the second
The configuration of the traveling body 15 is shown in a sectional view.

In such a configuration, when the wire rope 12 extends over time, the extension is such that when the locking point 20 is on the slack side of the wire rope 12 with respect to the drive pulley (not shown). The rope 12 gathers from the drive pulley to the locking point 20, but the tension spring 21 pulls the locking point 22 at the other end of the plate 19 to pull the plate 19 together with the outer ring of the rotary one-way clutch 17. This movement is rotationally moved in the direction of arrow B and does not return in the direction opposite to arrow B by the action of the rotary one-way clutch 17, so this extension is reliably absorbed.

On the contrary, when the locking point 20 is on the tension side of the wire rope 12 at the time of starting, a large force is applied in the direction of arrow C in the figure, but the plate 19 applies a large force to the rotary one-way clutch 17, Since the plate 19 is fixed to the outer ring of the rotary one-way clutch 17 via the sleeve 18, it is not returned in the direction opposite to the arrow B.

The method of hanging the wire rope for moving the first traveling body and the second traveling body at a speed ratio of 2: 1 is not limited to the example shown in FIG. 2, and as shown in FIG. It is also possible to provide only 13 and construct with only one wire rope.

Next, FIG. 5 shows a modification of the main part 10.
That is, the shaft 16 is positioned at one end of the plate 19 and the locking point 20 of the wire rope 12 is positioned at the other end, and the locking point 22 between the locking point 20 and the shaft 16 and the second A tension spring (21) is stretched over a locking point (23) formed on the running body (15).

Further, FIG. 6 shows a structure in which, when the protruding portion E shown in FIG. 4 (b) is an obstacle, the protruding portion E is on the opposite side. That is, the outer ring of the rotary one-way clutch 17 is fixed to the second traveling body 15, the shaft 16 is identified to the inner ring of the rotary one-way clutch 17, and the plate 19 is fixed to the shaft 16.

In addition, in the above-mentioned embodiment, the state applied to the image reading apparatus has been described, but it can be applied to a wire rope stretch absorbing device of a device for driving a traveling body by a wire rope such as an electrophotographic copying machine or a printer. It is possible.

Effects As described above, the present invention fixes the inner ring to the cylindrical shaft fixedly mounted on the machine frame or the traveling body to fix the rotary one-way clutch, and the outer ring of the rotary one-way clutch has the wire rope of the wire rope. A plate whose one end is locked is fixed, and a tension spring is stretched between the plate and the machine frame or the traveling body so as to urge the plate in the direction in which the wire rope is stretched, or An outer ring is fixed to the machine frame or the traveling body to provide a rotary one-way clutch, and a plate fixed at one end of the wire rope is fixed to a shaft fixed to an inner ring of the rotary one-way clutch, By applying a tension spring between the plate and the machine frame or the traveling body so as to bias the plate in the direction in which the wire rope is stretched, when a strong force is applied to the wire rope. Can surely absorb the growth,
Also, even if the elongation is slight, it can be absorbed and the tension of the wire rope can be constantly maintained at a constant level.
In addition, there is an effect that the degree of freedom in design is increased without being restricted by the mounting position and the space.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an image reading apparatus to which the present invention is applied, FIG. 2 is a front view showing an embodiment of the present invention, and FIG.
The figure is a front view showing an example in which the method of hanging the wire rope is different, and FIG. 4 (a) is a front view showing the main part of the present embodiment.
FIG. 6B is a horizontal sectional view thereof, FIG. 5 is a front view showing a modified example thereof, FIG. 6A is a front view showing yet another modified example, and FIG. 6B is a horizontal sectional view thereof. , FIG. 7 is a front view showing a conventional example, and FIG. 8 is a plan view of a wire rope winding portion. 12 ... Wire rope, 15 ... Traveling body, 16 ... Shaft, 17 ... Rotation type one-way clutch, 19 ... Plate, 21 ... Tension spring

Claims (2)

[Claims] 1. A traveling body capable of reciprocating along a guide member fixed to a machine frame is provided, and the traveling body is wound around a pulley provided on the machine frame and the traveling body and a drive pulley driven by a drive source. A wire rope drive device configured to reciprocally drive the traveling body through wire ropes whose both ends are respectively locked to the machine casing or the traveling body, wherein a cylinder fixed to the machine casing or the traveling body Direction to stretch the wire rope by fixing the inner ring to the shaped shaft and fixing the rotary one-way clutch, and fixing the plate with one end of the wire rope locked to the outer ring of the rotary one-way clutch An extension and absorption device for a wire rope, wherein a tension spring is bridged between the plate and the machine frame or the traveling body so as to urge the plate. 2. A traveling body that can reciprocate along a guide member fixed to the machine frame is provided, and the traveling body is wound around a pulley provided on the machine frame and the traveling body and a drive pulley driven by a drive source. With the wire rope drive device configured to reciprocally drive the traveling body through the wire ropes whose both ends are respectively locked to the machine casing or the traveling body, the outer ring is fixed to the machine casing or the traveling body. A rotary one-way clutch is provided, a plate fixed at one end of the wire rope is fixed to a shaft fixed to the inner ring of the rotary one-way clutch, and the plate is attached in a direction in which the wire rope is stretched. An extension absorbing device for a wire rope, characterized in that a tension spring is bridged between the plate and the machine frame or the traveling body so as to urge it.