JPH0454980Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a belt roller suspension device suitable for use in an endless belt-like body, particularly an electrophotographic photoreceptor belt.

(Prior Art) In electrophotographic printers and the like, a method is known in which a photoreceptor sheet is formed into an endless belt-like member, and the photoreceptor sheet is wound between a separated driving roller and a driven roller to transport the photoreceptor.

In this method, in order to achieve accurate feeding, a photoreceptor belt 61 is usually wound between a driven roller 60 and a drive roller (not shown) as shown in FIG. 6 (a perspective view of the area around the driven roller), and the roller shaft 62 is The photoreceptor belt 61 is inserted into a U-shaped bearing 64 provided on the body 63, and a coil spring 65 is stretched between the roller shaft 62 and the body to apply a certain tension to the photoreceptor belt 61.

That is, in this type of electrophotographic printer, etc., if the tension of the photoreceptor belt is loose, the following problems will occur. First, the photoreceptor belt and drive roller slip, making it impossible to achieve accurate synchronization. Also,
Due to unevenness such as waviness on the surface of the photoreceptor belt, it becomes impossible to maintain a constant gap with respect to the photoimage exposure section, the development section, the transfer section, the uniform charging section, and the like. Furthermore, the surface of the photoreceptor belt vibrates, causing the toner to come off and causing a significant deterioration in image quality.

Therefore, all conventional systems employ a suspension structure in which the driven roller is supported by a predetermined biasing means such as a spring.

(Problems to be Solved by the Invention) As mentioned above, a photoreceptor using an endless belt-like member generally requires the following conditions.

Necessary and sufficient tension is applied to the photoreceptor belt.

Capable of absorbing manufacturing errors in the total length of the photoreceptor belt.

The photoreceptor belt should not be plastically deformed due to unnecessary tensile force.

The photoreceptor belt should not be affected by internal and external vibrations and cause flapping, etc.

However, in the conventional suspension structure described above, tension is applied to the photoreceptor belt even when the photoreceptor belt is not in use, such as during transportation or storage, so the photoreceptor belt may stretch (plastic deform) if left unused for a long period of time. In addition, in order to prevent such problems, the spring is reversed with respect to the roller axis when not in use so that no tension is applied to the photoreceptor belt, but this takes up a large amount of space and increases the size and size. There are problems in that the structure becomes complicated, the operability deteriorates, and the product quality deteriorates due to loss of appearance.

Furthermore, since it is supported by a spring, vibrations cannot be absorbed, and for example, unevenness at the joint of the photoreceptor belt causes the driven roller to swing, resulting in a problem of deterioration of image quality.

The present invention provides a belt roller suspension device that further solves these problems.

(Means for Solving the Problems) As shown in FIG. 1, the present invention rotatably supports a belt roller 3 around which an endless belt-like body 2, such as a photoreceptor belt for electrophotography, is wound around a body 4. This device is applied to a suspension device 1 for a belt roller, and its features include a suspension member 6 rotatably inserted into a circular hole 5 provided in a body 4, and a suspension member 6 that is attached to the center of the suspension member 6 in a radial direction. A long oval bearing part 7 is provided, and a buffer member 9 for biasing a roller shaft 8 fixed to the bearing part 7 toward one end 7a of the bearing part 7 is disposed inside the bearing part 7, for example.

(effect) Next, the operation of the present invention will be explained.

FIGS. 5A, 5B, and 5C each show the position of the suspension device according to the present invention, as follows.

A Assembly position B Storage position C Usage position Each position mode will be explained below along with its function.

[Assembly position A]

In this position, the bearing portion 7 is approximately parallel to the feeding direction of the belt-like body 2, and the roller shaft 8 is located on the side of the other opposing belt roller (not shown). That is, it is located on the side where the belt-like body 2 is loosened, and the roller shaft 8 is located at one end 7a of the bearing portion 7 by the buffer member 9. In this case, the belt-like body 2
is in the loosest state and is easy to assemble.

[Storage position B]

Next, the suspension member 6 is rotated approximately 90 degrees in the direction of arrow P. Thereby, the bearing portion 7 becomes substantially perpendicular to the feeding direction of the belt-like body 2. Note that movement of the roller shaft 8 in the substantially perpendicular direction is restricted. Therefore, as the roller shaft 8 rotates, the buffer member 9 is compressed by the cam action of the bearing portion 7, and the roller shaft 8 is fixed at a substantially central position of the suspension member 6. In this case, the belt-like body 2 is less loose than in the position shown in FIG. 5A, but no tension is applied yet, and the belt-like body 2 is in a state suitable for storage and transportation.

[Usage position C]

Next, the suspension member 6 is further roughly moved in the direction of arrow P.
Rotate it 90°. As a result, the bearing portion 7 becomes substantially parallel to the feeding direction of the belt-shaped body 2, but is reversed from the position shown in FIG. 5A, and the buffer member 9 is located on the other belt roller (not shown) side. In this case, the roller shaft 8 can be displaced within the bearing part 7, and is biased in the direction of tensioning the belt-like body 2 due to the elastic force of the buffer member 9, so that the belt-like body 2 is in a balanced position in the bearing part 7. It is held at a position slightly outside the center.
Therefore, since the roller shaft 8 is elastically supported by the buffer member 9, it also provides an effective buffering effect against vibrations of the belt-shaped body 2.

The above operations can be performed simply by rotating the suspension member 6.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

Figures 1 and 3 are longitudinal sectional side views of the suspension system according to the present invention, Figures 2 and 4 are front views of the suspension system seen from inside the fuselage, and Figures 1 and 2 are assembled. 3 and 4 respectively show the position of use.

The embodiment shows a case where the present invention is applied to an electrophotographic printer. Such a printer uses a photoreceptor belt 20 as the belt-like body 2. The photoreceptor belt 20 is formed into an endless belt-like body of a photoreceptor sheet in which a photoconductor is laminated on a conductor substrate, and has low elasticity. The total length of the photoreceptor belt 20, that is, the length of the entire circumference is the third
In the usage position shown in the figure, the roller shaft 8 is selected so that the tension can be balanced at a position where the roller shaft 8 is slightly biased outward (in the tension direction) from the center 0 of the bearing portion 7. In addition, this biased distance is about several millimeters from the center 0 in the embodiment.

The photoreceptor belt 20 is wound around at least a drive roller (not shown) and a driven roller 21 . A roller shaft 8 protruding from both ends of the driven roller 21 is rotatably supported by a pair of left and right suspension devices 1 which are symmetrically constructed, and the drawing shows only one (left side) suspension device.

Next, the specific configuration of such suspension device 1 will be explained.

A circular hole 5 is bored in the fuselage 4. This circular hole 5 is provided with a matching groove 23 for positioning in the axial direction. Further, click recesses 22 having a triangular cross section are provided on the inner peripheral surface of the circular hole 5 at 90° intervals.

The suspension member 6 has a cylindrical shaft portion 30 that is rotatably inserted into the circular hole 5.
It has an axial length that is approximately the same as the axial length of. Cylindrical shaft part 30
A knob portion 31 having a diameter larger than the outer diameter of the shaft portion 30 is integrally formed at the outer end of the shaft portion 30 . A protruding lever 32 is integrally provided on the outer periphery of the knob portion 31. Moreover, an elongated concave bearing part 7 which is elongated in the radial direction is formed at the center on the inner end surface of the cylindrical shaft part 30, and a step recess part 33 is formed at the periphery of the opening side end thereof. A collar member 8a that is slidably guided in the longitudinal direction is inserted into the bearing portion 7, and a flange portion 8b that engages and slides on the step recess 33 is integrally formed at the end of the collar member 8a. A roller shaft 8 is rotatably inserted into this collar member 8a.

On the other hand, a buffer member 9 is provided inside the bearing portion 7 . The buffer member 9 includes a leaf spring 40 with one end supported on the bottom side of the other end 7b of the bearing portion 7.
The other end is curved in an arc toward the opening side of the bearing portion 7 and is pressed against the outer circumferential surface of the collar member 8a. Further, the interior of the bearing portion 7 on the curved concave side of the leaf spring 40 is filled with a polymer foam spring 41, a so-called sponge block. As a result, the leaf spring 40 is further curved due to the displacement of the collar member 8a, and the foam spring 41
is compressed. Both springs 40 and 41 have a buffering function, and the synergistic action of both springs can provide an optimal buffering force.

On the other hand, the fitting groove 2 is provided at the inner end of the cylindrical shaft portion 30.
3 is integrally provided with a protrusion 34 that engages with. The position of this protrusion 34 is aligned in the assembly position,
The cylindrical shaft portion 30 can be inserted into the circular hole 5. On the other hand, when the projection 34 is rotated after insertion, the protrusion 34
It has a function of locking onto the inner wall surface 4a of and preventing it from coming off.

Further, a click spring 35 having one side of a triangle notched is attached to the outer peripheral surface of the cylindrical shaft portion 30, and this click spring 35 is elastically engaged with the click recess 22 on the circular hole 5 side. As a result, the suspension member 6 is held within the circular hole 5 every 90° and can be rotated in a click manner. This holding position corresponds to the above-mentioned assembly position, storage position, and use position (fifth position).
(see figure). Note that the click mechanism of the embodiment constitutes a ratchet mechanism that rotates in only one direction.

Next, a method for assembling and using the suspension device 1 will be explained. FIG. 5 shows a perspective view of the suspension system.

First, in the assembly position shown in FIG. 1 or FIG. 5A, the matching groove 23 and the projection 34 are brought into matching engagement, and the suspension member 6 is inserted into the circular hole 5. At this time, click spring 3
5 is also embedded at the same time. Further, the roller shaft 8 is inserted into the collar member 8a that has been assembled in advance to the bearing portion 7. After the assembly is completed, the knob 31 is rotated and set in the storage position. On the other hand, this state is maintained until it is used, and when it is used, the knob part 31 is
Rotate and set it to the use position.

Although embodiments have been described above, the present invention is not limited to these embodiments. For example, it is particularly suitable for transporting an electrophotographic photoreceptor belt as in the embodiment, but it can of course be used as a belt roller suspension device in any device. Further, as the buffer member, an arbitrary member having another buffer function such as a composite spring can be used. Note that the collar member can be omitted by bending the tip of the leaf spring into a U-shape. Other arbitrary changes in the shape, structure, arrangement, etc. of details that do not depart from the gist of the present invention are permitted within the scope of the present invention.

(Effect of the invention) As described above, the belt roller suspension device according to the invention includes a suspension member rotatably inserted into a circular hole provided in the machine body, and a radially elongated elliptical shape at the center of the suspension member. Since a bearing is provided and a buffer member is disposed to bias the roller shaft supported by the bearing toward one end of the bearing, the following significant effects can be obtained.

First, there is no need for a conventional coil spring or its installation space, and only a space for a relatively small buffer member that can be formed into a cylindrical shape, for example, is sufficient. Therefore, the device can be made significantly smaller and more compact, and because of its simple structure, assembly efficiency can be improved and costs can be effectively reduced.

Second, the belt-like body can be kept loose when not in use, and problems such as elongation of the belt-like body can be prevented. Moreover, the switching operation can be performed extremely easily.

Thirdly, by using a buffer member, especially a leaf spring and a polymer foam spring according to an optimal embodiment, the vibrations generated in the belt-like body can be effectively absorbed, and the image quality can be improved. can be achieved.

Fourthly, according to the optimal embodiment, the buffer member can be housed inside the suspension member, and it is possible to dramatically improve the appearance shape and marketability.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional side view of the suspension device according to the present invention in the assembled position, Fig. 2 is a front view in the direction of arrow H in Fig. 2, Fig. 3 is a longitudinal sectional side view of the suspension device in the use position, and Fig. 4 3 is a front view in the direction of arrow K in FIG. 3, FIGS. 5A, B, and C are perspective views of a suspension system according to the present invention, and FIG. 6 is a perspective view of a suspension structure according to a conventional example. In the drawings, 1... suspension device, 2... endless belt-like body, 3... belt roller, 4... body, 5...
Circular hole, 6...Suspension member, 7...Bearing portion, 8...Roller shaft, 9...Buffer member.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a belt roller suspension device that rotatably supports a belt roller around which an endless belt-like body is wound around a machine body, a suspension member rotatably inserted into a circular hole provided in the machine body is provided. The suspension member is provided with an elongated radially long oval bearing at the center of the suspension member, and a buffer member is provided for biasing a roller shaft supported by the bearing toward one end of the bearing. A suspension device for belt rollers. 2. The belt roller suspension device according to claim 1, wherein the endless belt-like body is an electrophotographic photoreceptor belt. 3. Utility model registration claim 1, characterized in that the suspension member is provided with a click mechanism in which the bearing portion is held on the machine body in positions substantially parallel and substantially perpendicular to the running direction of the endless belt-like body. Suspension device for belt rollers. 4. The belt roller suspension device according to claim 1 or 3, characterized in that a knob is provided on the outside of the suspension member. 5. The belt roller suspension device according to claim 1 or 3, wherein the bearing portion is formed in a concave shape inside the suspension member. 6. The belt roller suspension device according to claim 1, wherein the roller shaft has a rotatable collar member fitted therein. 7. The belt roller suspension device according to claim 1, wherein the buffer member is made of a polymer foam spring and/or a leaf spring. 8 Utility model registration claim 1 or 7 characterized in that the buffer member is disposed inside the bearing part
A suspension device for belt rollers as described in .