JPS6018685Y2 - Reciprocating drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that performs reciprocating motion, such as a document table drive device of an electrophotographic copying machine.

Electrophotographic copying machines move the optical system and the original relative to each other in order to scan the slit of the original, but in those that keep the optical system stationary and move the original, the original stand on which the original is placed is used. make a linear reciprocating motion.

An example of this document table driving device is shown in FIG.

Reference numeral 1 denotes a transparent document table, which is supported by a frame (not shown) so as to be slidable in the direction of arrow A.

A wire 6 has both ends fixed to the document table 1, and is wound around a pulley 2.3.4 pivotally supported by the frame.

That is, the wire 6 has one end connected to the hook 1 of the document table 1.
a, and then the pulley 2 changes the direction in a U-shape, wraps it around the pulley 3, then changes the direction with the pulley 4, wraps it around the pulley 2 again, and attaches the other end to the original platen 1. The pulley 4 is biased by a spring 5 to apply tension.

The pulley 3 is driven in both forward and reverse directions via a clutch.

When the pulley 3 is driven counterclockwise, the document table 1 moves to the right.

The supply of driving force to the pulley 3 is cut off just before the document table 1 reaches both ends of its range of motion, and the subsequent movement due to inertia causes the document table 1 to be moved by dampers (not shown) at both ends of its range of motion. Braking is achieved by colliding with the vehicle.

However, in the above-mentioned apparatus, the structure is complicated because it is necessary to drive the pulley 3 in both forward and reverse directions, and the movement of the document table 1 becomes inaccurate due to the elongation of the wire 6.

FIG. 2 shows another example of the conventional document table driving device.

7 is an endless chain, which is stretched between sprocket wheels 8 and 9;
By driving, the vehicle travels in one direction as marked by arrow B.

A joint 10 is fixed to the document table 1, and a slit 11 is provided therein.

The running direction B of the chain 7 is the direction A of the reciprocating movement of the document table 1.
, but the direction of the slit 11 is perpendicular to them.

A pin 12 is fixed to the chain 7.
is inserted into the slit 11.

When the chain 7 is run in the direction of arrow B, the pin 12
When it is above the loop of the chain 7, it runs to the left, so the document table 1 passes through the joint 10,
It moves to the left in conjunction with the pin 12.

When the pin 12 rotates around the sprocket wheel 8, the pin 12 moves within the slit 11 from top to bottom.

The movement of the document table 1 at this time changes in a cosine manner and changes from leftward to rightward.

The pin 12 that has revolved around the sprocket wheel 8 travels to the right under the loop of the chain 7, so that the document table 1 moves to the right.

As the pin 12 moves around the sprocket wheel 9, it moves from bottom to top in the slit 11, and the direction of movement of the document table 1 is reversed in the same way as before.

The second document table driving device uses the chain 7, and has the advantage that there is no risk of the chain elongating and the driving force can be applied in one direction, thus eliminating the disadvantages of the first document table driving device. However, on the other hand, it has the following drawbacks.

That is, when the document table 1 changes its direction of motion, it does so in a cosine manner, but since inertia is acting on the document table 1, a large force due to this inertia is exerted on the pin 12 and the joint 10. There is a risk that it may get stuck and deform or break.

In the first document table drive device, the shock when reversing the driving direction of the second document table 1 was not a problem because it was absorbed by the damper, but in the second document table drive device, Since the movement of the platform 1 is always restrained by the chain 7, it is difficult to absorb the shock with a damper.

The present invention aims to solve the above-mentioned problems, and FIGS. 3 and 4 show examples thereof.

Endless chain 7 connects sprocket wheels 8 and 9
It is the same as the above-mentioned conventional one in that it is spanned between them and runs in the direction of arrow B, and that the pin 12 is fixed thereto.

A joint 13 is fixed to a document table 1 that is supported so as to be able to reciprocate in the direction of arrow A.

As detailed in FIG. 4, the joint 13 is provided with a slit 14 that bulges in the center, and the pin 1 is inserted into this slit 14.
2 has been inserted.

The document table 1 reciprocates between the home position shown in FIG. 3A and the folded position shown in FIG. 3C, and the damper 15.
16 is the arrangement.

The slit 14 of the joint 13 is formed so that the width y of the narrow parts 14a and 14b at both the upper and lower ends thereof is slightly larger than the diameter of the pin 12, and the upper and lower dimensions thereof are larger than the loop width X of the chain 7. Selected.

The enlarged portion 14c of the slit 14 is connected to the narrow portions 14a and 14b by a smooth curve inside the loop width X, and its maximum width 2 is sufficiently larger than the width y of the narrow portions 14a and 14b. It is.

When the chain 7 starts running in the direction of arrow B from the state where the document table 1 is at the home position shown in FIG. 3a,
The pin 12 is inserted into the small part 1 of the slit 14 of the joint 13.
4a, and drives the document table 1 to the left as shown in FIG.

A document (not shown) on document table 1 is scanned by the optical system due to this movement.

As shown in FIG. 3C, when the document table 1 reaches the left end of its movement range, that is, the folded position, the pin 12 also reaches the sprocket wheel 8 and rotates, so that the pin 12 is inserted into the narrow part of the slit 14. Descending from the part 14a, the ampullae part 14c
Move to.

At the same time, the joint 13 collides with the damper 16.

Although the document table 1 continues to move toward the left due to inertia, this movement is stopped by the damper 16.

In this case, the connection state between the pin 12 and the joint 13 is as follows:
Since it is loosened by the enlarged portion 14c of the slit 14, the document table 1 is not restrained by the chain 7, and its leftward movement is stopped by the action of the damper 16.

Subsequently, the pin 12 enters the narrow portion 14b of the slit 14 and travels to the right as shown in FIG. 3d, so that the document table 1 makes a return movement and returns to the home position shown in FIG. 3a and stops. do.

At this time, as the pin 12 moves to the enlarged portion 14c of the slit 14, the connection between the document table 1 and the chain 7 is loosened, so the document table 1 stops while absorbing the shock due to the action of the damper 15. do.

In the embodiment described above, the chain 7 was used to drive the document table 1, but a wire may be used instead of the chain 7, and other flexible drive members may also be used.

Furthermore, the driven member is not limited to the document table; for example, it can also be used as an optical system drive device of a copying machine that moves the optical system back and forth while keeping the document stationary, and can also be used as other general reciprocating drive devices. Available.

As described above, the present invention provides a pin protruding from an endless flexible driving member that is stretched between a plurality of cars, and inserts this pin into a slit provided in a driven member.
In the device in which the driven member is caused to reciprocate by traveling in one direction of the driving member, an enlarged portion whose width is enlarged is provided at the center of the slit, so that the driven member can move within its range of motion. Upon reaching both ends of the pin, the pin becomes free within the slit and the connection between the driven member and the driving member is loosened.

Since the driven member in this state is caused to collide with the damper, the damper absorbs the shock caused by the reversal of the direction of movement or the stopping of the driven member without giving any reaction to the driving member. Ru.

Therefore, damage to drive members, pins, slits, etc. can be prevented, and quiet operation can be achieved.

[Brief explanation of the drawing]

FIGS. 1 and 2 are front views showing two examples of conventional document table driving devices. FIG. 3 is a front view showing an embodiment of the present invention.
are respectively indicative of different operating states. FIG. 4 is an enlarged front view of the joint. 1...Original table, 7...Chain, 8,
9... Sprocket wheel, 12...
Zen, 13...Joint, 14...
Slit, 14c... Ampulla, 15, 16...
...damper.

Claims (1)

[Scope of utility model registration request] By providing a pin protruding from an endless flexible driving member that is stretched between multiple cars, and inserting this pin into a slit provided in the driven member, the driving member can be moved in one direction. , in which the driven member is caused to reciprocate, an enlarged portion whose width is enlarged is provided in the center of the slit, and the slit is disposed at both ends of the movement range of the driven member, and A reciprocating drive device characterized by being provided with a damper against which members collide.