JPH0320579Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a safety device for a roller drive mechanism used in a copying machine or the like.

[Prior art and problems]

The paper on which the toner image is fixed in the copying machine is
The paper ejection roller mechanism installed in the copying machine body allows
The paper is ejected outside the machine, but in the conventional mechanism, the rotating part of the paper ejection roller was exposed, making it dangerous for the operator to get his or her hands caught.

In addition, in order to prevent this, it has been proposed to cover the paper ejection roller section with a cover or install the roller deeper than the machine exterior, but
This was not desirable in order to improve the overlapping on the tray.

Further, since the roller shaft and the drive transmission member are fixed, the roller remains driven during the copying operation.

Other conventional examples have been proposed in which a frictional engagement portion is provided in the middle of a series of transmission shafts that drive the rollers, and in which a slip mechanism is provided.

However, these disadvantages include damage to other drive systems when a high load is applied, and recovery after removal of a high load is not easy.

[Purpose of invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a roller drive mechanism that stops the drive of the rollers even if a hand touches the paper ejection rollers, allows safe copying, and allows for easy recovery.

[Key points of the idea]

In order to achieve the above object, the present invention provides a paper ejection roller drive mechanism that drives a paper ejection roller that is configured to be accessible from the outside of the apparatus. The drive gear is made of a non-magnetic material and has a shaft hole to be fitted, a recess with an opening on the inner surface of the shaft hole, and a magnetic attraction member slidably housed in the recess. When the member is attracted to the paper ejection roller shaft, driving force is transmitted from the drive gear to the paper ejection roller shaft, and when a load of more than a predetermined value is applied to the paper ejection roller, the drive force is transmitted to the paper ejection roller shaft. The present invention is characterized in that the driving gear slips and the driving force to the paper ejection roller shaft is cut off.

[Example of idea]

Next, the roller drive mechanism of the present invention will be described in detail with reference to the drawings.

The roller drive mechanism consists of a drive roller 21 and a driven roller 22, and the driven roller 22 is connected to a side plate 23.
a, 23b and rotatably supported by bearings 24a, 24b.

Further, the driven roller 22 is made up of a plurality of rollers 26 fixed to a core metal 25 at appropriate intervals.

In the drive roller 21, a plurality of rollers 28 are fixed to a core metal 27 at appropriate intervals, and both ends of the core metal 27 are rotatably supported on side plates 23a and 23b by bearings 29a and 29b. And drive roller 2
The roller 28 of No. 1 and the roller 26 of the driven roller 22 contact each other and slide and rotate.

On the other hand, a gear 30 is locked at one end of the drive roller 21 and on the outside of the side plate 23a.

As shown in FIG. 4, the gear 30 is composed of a gear 32, a guide protrusion 33, and a pair of arms 34.

The guide projection 33 is longer than the arm 34, and the guide projection 33 is longer than the arm 34.
It is erected with a space between the two.

The arms 34 are elastic and each has a hemispherical portion 34a at its tip.

Further, an engagement hole 35 is formed on the side of the core metal 27 of the drive roller 21 on which the gear 30 is engaged, and a ring groove 36 is formed beyond the engagement hole 35 .

The gear 30 having the above configuration is inserted into the core metal 27 of the drive roller 21 as shown in FIG.
It is locked and stopped. In addition, the guide protrusion 33
is prevented from coming off by a ring 37 that is locked in a ring groove 36.

On the other hand, the gear 30 meshes with a gear 31 driven by a drive source (not shown) of the main body.

Next, the operation of the present invention will be explained.

A sheet of paper on which an image has been fixed in the fixing process of a copying machine is discharged from the machine by a paper discharge roller.

Now, if the operator of the copying machine accidentally touches the discharge roller with his finger, a load exceeding a predetermined value is applied to the drive roller 21. Then, the rotational force of the gear 32 was transmitted to the shaft 27 via the elastic arm 34, but the hemispherical portion 34a of the arm 34 and the engagement hole 35 disengaged, as shown in FIG. state.

The elastic arm 34 has elastic force in the direction of engagement with the engagement hole 35, but when a predetermined load is applied,
The engagement is disengaged and the roller is not driven.

Further, when the excessive load is removed, the drive roller 21 automatically starts being driven by the gears 30 and 31.

Here, the material of the gear 30 may be integrally formed from metal, or may be integrally formed from synthetic resin.

Further, the gear 30 connects the guide protrusion 33 to the ring 37.
Since the end of the arm 34 rotates smoothly without coming into contact with the ring.

In another embodiment of the present invention, as shown in FIGS. 5 and 6, the gear 38 is made of non-magnetic material, and the shaft hole 39
A plurality of radial slits 40 are bored in the. Further, a magnet 41 is slidably embedded in the slit 40.

On the other hand, the drive roller shaft 42 is made of a magnetic material such as iron, and a ring 37 is fitted into a groove 43 at the tip.

The gear 38 configured as described above meshes with the gear 31 driven by a drive mechanism provided in the main body of the copying machine (not shown) and rotates.

On the other hand, the plurality of magnets 41 are connected to a shaft 4 made of a magnetic material.
2 and is slidably embedded in the radial slit 40 of the gear 38, so when the gear 38 rotates, the shaft 42 also rotates together.

Here, when a high load is applied due to the operator's hand touching the paper ejection roller, the gear 38 and the shaft 42 are magnetically coupled by the magnet 41, so the load exceeding the magnetic force will slip and be transmitted. is blocked.

[Effect of idea]

According to the roller drive mechanism of the present invention described above, when a high load is applied to the paper ejection roller, the driving force is cut off and the roller stops, so it is safe even if the operator touches it. be.

Furthermore, even when a high load is removed, the drive mechanism can be easily returned to its original state without damaging other drive systems.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention, Fig. 2 is a sectional view of the main part thereof, Fig. 3 is a partially cutaway view showing the operating state, and Fig. 4 is a diagram showing the first embodiment. FIG. 5 is a sectional view showing another embodiment of the present invention, and FIG. 6 is a side view thereof. 21... Drive roller, 22... Followed roller, 2
3a, 23b...Side plate, 24a, 24b, 29
a, 29b... Bearing, 25, 27... Core metal, 2
6, 28...Roller, 30, 31, 38...Gear, 32...Gear, 33...Guide protrusion, 34...
...Arm, 34a... Hemispherical part, 35... Engagement hole, 36
...Groove, 37...Ring, 39...Shaft hole, 40...
...Slit, 41...Magnet, 42...Axis.

Claims (1)

[Scope of utility model registration request] In a paper ejection roller drive mechanism that drives a paper ejection roller configured to be accessible from the outside of the device, a paper ejection roller shaft made of a magnetic material, a shaft hole that is loosely fitted to the paper ejection roller shaft, and an inner surface of the shaft hole are provided. A drive gear made of a non-magnetic material in which a recessed portion having an opening is formed, and a magnetic attraction member slidably housed in the recessed portion, and the magnetic attraction member is attracted to the paper ejection roller shaft. The drive force is transmitted from the drive gear to the paper ejection roller shaft, and when a load of more than a predetermined value is applied to the paper ejection roller, the drive gear slips with respect to the paper ejection roller shaft, causing the paper ejection roller shaft to slip. A roller drive mechanism characterized in that the driving force to the roller is cut off.