JPH0223865B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method and apparatus for metering flowable materials from a tank or storage chamber, and is particularly useful in electrophotographic reproduction machines. More particularly, the invention provides a method for transporting a powdered flowable material, such as an electrophotographic toner or the like, from a storage container to another area where the powdered material is used in a process such as developing an electrophotographic image. It is about doing so. The present invention is particularly suited for transferring toner from a storage container to a reservoir of a development unit of an office copier.

BACKGROUND OF THE INVENTION It has been known for some time to convey flowable materials, such as dry powders, from a tank to a processing area using rotating rollers with flexible plates that engage the peripheral surface of the roller to provide a dynamic seal. Are known. As the roller surface passes through the material in the storage area, powder can be trapped or deposited on the roller surface, and after this material has passed through the area defined by the peripheral edge that engages the sealing plate,
It is taken out by rollers. For example, Dunaway US Pat. No. 3,114,482 shows this type of device.

Similar metering devices under Dunaway have been applied in the electronic reprographic industry for the purpose of dispensing toner from a tank to the active development area of a copier. For example, U.S. Pat. No. RE 28,589 to Knight et al. shows an apparatus of this type that includes a toner transporting element having a roller with a series of circumferential flutes on its outer surface. The toner is trapped in these grooves and transported through the flexible seal plate so that it falls into the reservoir of the active developer unit of the copier. The method of capturing toner on the metering roller surface for dispensing from the reservoir is
Various shapes are known. For example, metering rollers are made of porous or other toner-absorbing materials forming the basic roller elements or their surfaces. Other metering rollers even have outwardly extending ridges and a single inwardly directed groove along the roller surface.

The operation of metering rollers in copying machines is controlled by various mechanisms. Some control systems include means for monitoring whether there is a need to transfer toner to the developer reservoir and rotating the transport rollers only when necessary. For example, some conventional copier systems produce developed patches on a photoconductive drum or belt of the copier and monitor the light reflectance of the patches to effectively deposit them onto the photoconductor. Checking the amount of adhered toner. As the toner content decreases, the reflectance of the patch changes. A controller, such as a microprocessor or other controller, rotates the toner transport roller one to several revolutions, depending on the reflectivity of the patch, to remove toner from the replenishment reservoir and deposit it on the active developer device. Various other systems for monitoring developer toner density are known in the prior art, but as they are not relevant to the subject matter of the present invention, they will not be discussed in further detail here.

Unfortunately, the toner within the reservoir tends to form a cake-like agglomerate along the walls of the container and above the dispensing device. Therefore, the surface monitoring mechanism that contacts the toner in the tank may not be able to detect the presence of caked toner along the sides and falsely indicate that the amount of toner is at a minimum, or It may become stuck in a different position than it actually is, falsely indicating that excess toner is present.
The various techniques that have been used to overcome this caking problem have had mixed success. One method is to provide a stirring paddle that moves continuously along the container wall. Another method is to provide a vibrating screen or the like along the container wall, as shown in US Pat. No. 3,840,156. The caking problem described here is discussed in U.S. Pat. No. 3,964,648, which rotates within a cylindrical storage tank near its walls to break up the cake and remove some of the toner. This caking problem is attempted to be solved by an apparatus that is fundamentally different from the present invention in that it uses a rotating rod that feeds from a tank into the reservoir of the developer.

U.S. Pat. No. 4,044,719 shows a device in which a grooved rotary replenishment metering roll is engaged with a spring-like plate that loosely scrapes toner stuck to the metering roll. It does not address the problem of tank caking.

DESCRIPTION OF THE INVENTION The present invention is an apparatus and method for reliably metering flowable substances coming from a storage compartment that need to be stirred to prevent them from sticking to the storage compartment. The present invention uses an elongated metering roll with means around its periphery for receiving and removing flowable material, such as copying toner or the like. In this case, the material is placed in a storage chamber in which at least one flexible side is attached in an interlocking manner to the periphery of the roll. According to the invention,
The metering roll is rotatably mounted with respect to the storage chamber and is responsive to rotation means for transporting the flowable substance from the storage chamber over the peripheral engagement between the roll and the flexible wall. The roll is positioned by means of its attachment means such that the engagement between the roll and the flexible wall is in oscillatory movement radially about the axis of rotation of the roll in response to the rotary power means. Due to this structure and its positional relationship, the fluid material remaining in the storage chamber undergoes oscillating motion in response to the rotational movement of the rolls. The radial oscillatory movement of the line of mesh between the roll and the deflection wall can be achieved by rotating the cylindrical roll on an axis offset from its central axis or by rotating the cross-section of the metering roll with a shape other than circular. This can be achieved by placing the shaft in a central or eccentric position.

The invention can be implemented using a single flexible wall, blade or the like that engages the eccentrically moving roller surface around its periphery. however,
It is necessary to include means to prevent flowable material from escaping from the other side of the roller. However, in typical cases it is advantageous to use two flexible plates of resilient material, each mounted in a spring-like bias towards the roll surface. These plates can be arranged to engage the surface at a distance, so that the area on one side of the roll passes through the material in the tank as it rotates, and the area on the other side in the storage tank. pass through an area outside of When these rollers and plates are placed in the bottom opening of the tank, the rollers capture the flowable material as they rotate through the storage chamber;
It can be released by gravity when passing over the sealing plate. The arrangement of this double deflection plate is
It has the advantage of imparting maximum vibratory movement to the toner remaining in the storage areas on both sides of the metering roll, thereby breaking up the cake that forms around the edges.

The actual capture means, which are integrally attached to the roller surface, capture toner powder as it passes through the tank and drop these powders as it passes through the sump area. It can be shaped like this. The roller surface may also include outwardly extending ridges, inwardly extending grooves, or a combination thereof. The rollers may be provided with a bridge portion that straddles the inwardly extending grooves to prevent the edges of the flexure plates from entering the toner transport grooves and reducing toner metering.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments of the invention will be shown and described in connection with the environment of an electrophotographic reproduction machine development mechanism. As will become clearer in the explanation below,
The structure chosen in these examples works together to eliminate toner sticking or bridging to the side walls of the copier's toner supply chamber, thereby allowing toner to be delivered to the supply chamber when requested by the developer. This allows for relatively complete discharge from the

FIG. 1 shows a drum or photoconductor belt guide segment 10 having a photoconductive surface.
It is shown in a generally operative relationship with respect to developer device 12. Developing device 12
The housing has an opening 15 in which a toner supply device can be attached. That is, toner is first supplied to the supply chamber 16 and stored therein. Toner is metered from supply chamber 16 into auger chamber 18 where it is conveyed along the bottom of auger chamber 18 by auger 19 . Bulkhead 2
0 has an opening such as 21 at each end so that toner enters the developer chamber 22 through the opening at one end. Auger 24 is
The auger 19 rotates in the opposite direction, and the partition wall 20
through an opening at the opposite end from the developer chamber 22, thereby causing toner to flow continuously between the auger chamber 18 and the developer chamber 22 through a communication port or opening such as 21. recirculate.

The toner contained in developer chamber 22 is attracted to the surface of magnetic developer roll 25 and ultimately contacts the photoconductive surface of drum or belt guide 10 to form a latent image on the photoconductive surface of 10. develop. Operation of this mechanism is in a conventional manner.

Inside the supply chamber 16, a measuring roll 30 is mounted on the shaft 3.
2 so as to rotate eccentrically about the central axis of the roll 30. In the supply room 16,
Also included is a rod member 35, which extends through the side wall of the supply chamber 16, as seen in FIGS. (See Figure 2). When the level of toner in the supply chamber 16 drops below a certain minimum number, the rod member 3
A micro switch 38 is installed so as to be biased by an arm 36 of No. 5. With each rotation of the shaft 32, the cam similarly rotates to lift the arm 36 and drop the rod member 35 onto the top surface of the toner contained in the supply chamber 16, thereby causing the rod member 35 to drop onto the top surface of the toner contained in the supply chamber 16. It always follows the surface level of the toner applied. Rod member 35 rotates inner segment 39 along intrawall supply chamber 16 to increase sinking of toner from the side wall of the housing as the toner level decreases. Note that this acts as a toner level sensor and toner agitation device.

Flexible plate 40 made of spring steel or similar
are installed as shown in FIGS. 1 and 3. That is, the flexible plate 40 is curved so that it can be inserted between the holding portion 41 and the tab 42 of the partition wall 20. With this arrangement, the flexible plate 4
0 is biased toward the peripheral surface of roll 30 and can remain in engagement therewith during rotation of roll 30. When the roll 30 rotates in the direction of the arrow, the flexure plate 40 is in the dotted line position shown as 44. Roll 30 has grooves or flat areas 45 separated by one or more peripheral ridges 46 . In the example shown here (FIG. 2), two flat cut grooves 45A and 45B are separated by ridges 46A, 46B and 46C. As the roll 30 rotates eccentrically about the axis 32, the flat area 45 captures and conveys toner through the outer edge of the flexure plate 40 and drops it into the auger chamber 18. The ridge 46 allows the outer edge of the blade 40 to collect toner as it passes the front end 47 of the flexure plate 40 into a toner capture area or flat area 45.
Prevent from scraping.

Attached to outer wall 48 is another blade or flexure plate 50 which is retained within tabs 51 and 52 in a manner somewhat similar to flexure plate 40. That is, because of the spring-like nature of the flexible plate 50 and its attachment between tabs 51 and 52, the flexible plate 50 is constantly biased toward the peripheral surface of the roll 30, causing the edge 5
3 is in constant contact with the surface of the roll 30. Accordingly, the flexible plate 50 bends to the position shown in dotted lines as 54 and also bends to the position shown in dotted lines as 54.
This not only prevents the toner in the replenishment chamber 16 from leaking out, but also realizes a scraping function for dropping toner adhering to the peripheral surface of the roll 30 into the auger chamber 18. As a result of the eccentric movement of the roll 30 within the supply chamber 16 and the bending of the flexure plates 40 and 50 in response to the rotation of the metering roll 30, the toner within the supply chamber 16 undulates, thereby causing the toner to collide with the side walls of the housing. 20 and 48
Scaking or bridging is prevented. This facilitates complete discharge of toner from the supply chamber 16. In short, the flexure plate 40 acts as a metering spring with respect to the roll 30, while the flexure plate 50 acts as a cleaning spring;
and both constitute a continuous seal.

FIG. 4 shows the mechanical attachment of the roll 30 to the side wall 5.
5 illustrates a typical equipment arrangement for sealing against 5. The side wall 55 has a slight recess into which a sponge-like member 56 is fixed by adhesive or other means. Member 56 is made of any cellular material, such as polyurethane or the like. The rotational force on the roll 30 is coupled by a shaft 32 which is further mounted in the collar 57. Because member 56 is compressible, it remains sealed against the end surface of roll 30 and prevents toner from migrating through the mounting holes of shaft 30 in sidewall 55 and collar assembly 57. There is. Elastic sealing member 5
6 also engages the outer edges of the flexure plates 40 and 50 to prevent toner from leaking from the supply chamber 16. That is, the beads on the outer edges of the flexure plates 40 and 50 compress the member 56 somewhat in a manner similar to the roll 30 so that the sealing of the supply chamber 16 is maintained despite the flexure plates 40 and 50 bending. It becomes complete.

In operation, a driving force from a driving source (not shown) is supplied to the shaft 59 (see FIG. 2).
A clutch 58 operates in response to electrical or mechanical actuation to transfer rotational force from shaft 59 to shaft 3.
2 to the roll 30. When the typical controller determines that additional toner should be metered from the supply chamber 16 by some means, it energizes the clutch 58 and the controller determines that a sufficient amount of toner has been dispensed. Rotate the roll 30 once or several times until the During rotation of roll 30, toner is captured on flat area 45 of roll 30 and
It is conveyed through the sealing flexure plate 40 and is further ejected into the auger chamber 18 with the aid of the scraper edge 53 of the flexure plate 50. Flexible plate 40
and 50 vibrate between the positions shown in FIG. 3 to constantly shake the toner in the supply chamber 16. Similarly, the cam 37 reciprocates the level sensing rod member 35 to prevent sticking of the side wall and the replenishment chamber 16.
Helps detect the amount of toner inside.

A slightly different embodiment of the invention is shown in FIG. A supply chamber 70 containing toner 71 is shown here. In this case, the toner level sensor and toner agitation device 72 is shown as being rotatable about an axis 74 and having a grid of apertures, including a level sensing rod 3 .
There is an arm on the outside of the supply chamber 70 for energizing the microswitch in response to a cam movement similar to that discussed in connection with FIG. The horizontal material is 73
It is generally triangular like this, and sensor 7
2 on top of the toner and also helps to break up toner clumps when they fall into the supply chamber 70.

The eccentrically mounted metering roll 75 is again as previously described, at least as far as its attachment to the side walls 78 and 79 is concerned, by means of a metering spring-type deflection plate 76 on one side and a cleaning deflection plate 77 on the other side. It is sealed in a somewhat similar manner. The roll 75 has continuous vertical grooves 80,
No ridges are provided since groove 80 traps the toner within itself and flexure plate 76 seals the mouth of groove 80 as it passes from supply chamber 70 to auger chamber 81. In this case, the outer edge of the flexure plate 77 is positioned to ensure that toner is scraped from the groove 80 before entering the groove 80 and reentering the supply chamber 70.

Another arrangement is shown in FIGS. 6 and 7. In this case, the toner in the supply chamber 86 is sensed by a toner level sensing bar 88, which includes a single inverted V-shaped transverse arm that rests on top of the toner and also helps break up clumps. It has 89 on it. Eccentrically mounted metering roll 90
has an oval cross-section in this example and interfaces with the flexure plates 91 and 92 in a similar manner as previously described. However, the eccentrically mounted roll 90 is provided with an outwardly extending ridge or raised metering boss 95 for metering the toner passing through the sealing flexure plate 91, as shown in detail in FIG. Plate 92 acts as a scraper. The toner in the storage chamber 86 is transferred to the measuring roll 9
0 oscillates perpendicularly in the directions of arrows 96 and 97. Since the cross-section of metering roll 90 is not circular, when roll 90 rotates, it imparts an agitation effect to the toner in the supply chamber. The metering roll may be of circular cross-section and off-axis rotation, or circular in cross-section and rotated about a central axis, so long as the vibratory motion is imparted to one or more of the sealed peripheral plates. Let me point out that it can be done.

Another arrangement for sealing the supply reservoir against the side walls is shown in FIGS. 8 and 9. Flexible plate 100 is similar in construction and operation to weighing and cleaning flexible plates 40 and 50 of FIGS. 1 and 3. The flexible plate 100 has an elastic sealing pad 10
2 to the side wall 101. The pad 102 is made of a compressible material, such as polyurethane, that has a sticky surface that is sensitive to compression and is wrapped around and adhered to the edges of the flexure plate 100. That is, the compression of the wrapped edges of pad 102 creates a dynamic sealing interface with sidewall 101 to prevent toner leakage despite flexing of spring plate 100.

FIG. 10 shows a metering roll 104 in a manner suitable for use with those of FIGS. 8 and 9.
This figure shows the structure of a device for sealing the side wall 101. The roll 104 has side walls 101
It is mounted for eccentric rotation by a drive shaft 105 connected to a drive source (not shown) on the other side. Sealing assembly 106 includes:
It consists of a compressible core 107, which is attached to the roll 104 by gluing or adhering to an interface 108, such as with a pressure sensitive adhesive. The opposite side of the seal assembly 106 is
It is made of a wear-resistant layer 109 such as Mylar (trademark of EI du Pont de Nemours). The sealing assembly 106 is mounted generally in compression at the end of the metering roll 104 and remains compressed between the roll 104 and the sidewall during each rotation of the roll 104. Therefore, toner is prevented from leaking from the storage chamber into the developing device reservoir or the mounting hole of the drive shaft 105.

As shown in each of the above embodiments, the reciprocating motion of the metering roll surface imparts a kind of oscillating motion to the toner in the tank independently of the deflection plate. That is, the flexure wall can be realized by a relatively rigid flexure plate that is mounted and biased in a positive movement toward the metering roll surface. The combination of a spring-like deflection wall and eccentric movement of the metering roll surface according to the preferred embodiment has the advantage of maximizing agitation of the toner in the supply chamber.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention used in a developing device of a copying machine. 2 is a top view of the apparatus of FIG. 1; FIG. FIG. 3 specifically illustrates the roll operation of the structure of FIGS. 1 and 2;
It is an enlarged detailed view. Figure 4 is the same as Figures 1 to 3.
Figure 3 is a partially cutaway cross-sectional view of the roll mounting and plate sealing arrangement of the illustrated embodiment; FIG. 5 is a partially cutaway cross-sectional view of a second embodiment of the invention. Figure 6 shows
FIG. 7 is a partially cutaway, cross-sectional view of a third embodiment of the invention;
FIG. 7 is an enlarged view showing the weighing operation of the embodiment of FIG. FIG. 8 is an isometric view of an alternative arrangement for sealing the edges of the flexure plate. 9 is a cross-sectional cutaway view of the flexural seal of FIG. 8 showing its interaction with the sidewalls; FIG. FIG. 10 is a cross-sectional cutaway view of another metering roll and sealing structure. 16... Supply room, 35... Rod member, 20... Partition wall, 48... Outer wall, 40, 50... Flexible plate, 3
0...Measuring roll, 18...Auger chamber, 19,2
4...Auger, 21...Aperture, 25...Magnetic developing roll, 22...Developing chamber, 10...Photoconductor segment.

Claims (1)

[Claims] 1. A rotating cylindrical measuring roll and a storage chamber whose bottom is formed by a wall member that engages with the outer circumferential surface of the roll, and the fluid substance stored in the chamber is stored in a part of the outer circumferential surface of the roll. In the apparatus for supplying the fluid material through a gap formed between the fluid material release portion provided in the wall member and the wall member, the roll is eccentrically disposed around a rotating shaft installed inside the stored fluid material. When rotated, the outer circumferential surface of the wall member exerts an agitating action on the stored fluid material, and the end portion of the wall member that engages with the roll is rotated eccentrically so that the outer circumferential surface of the wall member exerts an agitating action on the stored fluid material during eccentric rotation of the roll. A supplying device for a fluid substance, characterized in that the device is movably supported so as to be driven by the movement of the fluid material and to reciprocate as a whole to impart a stirring action to the fluid material.