US3847306A

US3847306A - Developing apparatus

Info

Publication number: US3847306A
Application number: US00039686A
Authority: US
Inventors: R Howell; S Hotchkiss
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1970-05-20
Filing date: 1970-05-20
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12
Also published as: DE2125079A1; DE2125079B2; DE2125079C3; GB1353651A; CA949819A

Abstract

A developing assembly wherein a developing applicator receives electroscopic marking particles from a donor member supported in a sump housing, such housing having a resilient side wall which is flexed to reduce or prevent excessive accumulation of marking particles as a result of the donor member''s rotation.

Description

United States Patent 1191 Howell et al.

[ 1 Nov. 112, i974 1 1 DEVELOPING APPARATUS [75] Inventors: Richard Stockton Howell, Webster;

Stuart Evan Hotchltiss, Williamson,

both of NY.

[73] Assignee: Xerox Corporation, Stamford,

Conn.

[22] Filed: May 20, 1970 [21] Appl. No.: 39,686

152 US. 131 222/203, 222 414, 222/9101 511 lm. c1. oos 05/70 58 Field of Search 222/410, 414, D10. 1, 221,

[56] g References Cited UNITED STATES PATENTS Church 222/202 3.399.652 9/1968 (juwmn 222/57 X Primary Eraminer-Stanley H. Tollbcrg Assistant Examiner-John P. Shannon [57] ABSTRACT A developing assembly wherein a developing applicator receives electroscopic marking particles from a donor member supported in a sump housing, such housing having a resilient side wall which is flexed to reduce or prevent excessive accumulation of marking particles as a result of the donor members rotation.

7 Claims, 1 Drawing Figure PATENTEUHHY 12 I974 BY RICHARD HOWELL 5. M

Al TTORNEV 1 DEVELOPING APPARATUS This invention relates generally to donor assemblies for and method of making marking particles available to a'developing applicator in an apparatus wherein a latent image, either electrostatic or magnetic, is to be developed with such particles.

In conventional developing systems, a rotating cylindrical natural fur brush has'sometimes been used to convey marking particles referred to commonly as toner, into transfer relation with the latent image to be developed.

In the past, toner has been sprinkled or blown onto the brush as well as brought into contact with the brush via a donor assembly in the form of a solid cylindrical roller which rotates in a sump of developer, i.e.' toner and carrier bead mixture.

However, these approaches have suffered certain numeral 4. This toner is confined by two end plates 6 and a bottom member or panel 8 and a side wall 10.

The side wall 10 is comprised of two planar sections, oneof which is designated by reference numeral 11.

The other portion includes a rectangular frame 16 which is suitably attached to flanges of portion 11 and bottom plate 8. In its attached position, frame 16 holds in place a flexiblemember or diaphragm 14 across the opening in the sump housing between the aforemen- .tioned flanges and end plates 6. This flexible member date the donor roller 12 as it rotates within the housing.

One disadvantage is the effect of pumping or the uniform and constant movement of the developer in one direction as the donor roller moves through the sump. As the body of the roller moves, it pushes developerl before it and soon forms a cavity in the quantity of developer in the sump. Additionally, the prior art veloper to break up or fall into this cavity to the extent that the donor assembly would allow. Such techniques necessitated complex apparatus within the sump housing which took up space normally occupied by develope'r. I

Therefore, it is an object of the present invention to improve donor assemblies for toner conveyance to a developing member.

It is another object of the present'invention to provide an improved methodand means for agitating toner within the sump-of a developing assembly.

These and other objects which may become apparent are accomplished in accordance with the principles of the present invention wherein the housing for the donor assembly has a flexible wall or portion thereof which is flexed in a periodic manner to push compacted using agitators were helpful in solving the problem but or accumulated toner away from the wall and into renewed contact with the donor roller.

THese objects and other features of the present invention may be appreciated and better understood upon reading the following detailed description in connection with the appended drawings wherein the sole FIGURE illustrates a perspective view of a donor housing with parts broken away for simplicity to show the interior thereof.

The FIGURE shows clearly only one end of the housing. The end not shown, however, is substantially identical to the one illustrated.

The FIGURE illustrates a donor assembly housing This donor roller "also assists inkeeping the developer material or toner within the other portion of the donor housing. The portion of the donor roller 12 which is exposed to the outside of the donor housing is adapted to be contacted by rotating fibrous applicator 15, for example, shown in broken lines during the developing cycle. The donor roller may be'tubu'lar or solid and may be coated with an appropriate insulating material to aid in attracting in conveying toner to the developing appli-v cator. I

The donor roller may be driven to rotationby motive power applied to an input shaft 18 which corresponds to the axis of the donor roller 1-2 and is coupled thereto.

Mountedon the shaft 18 is an actuating cam 20 which along that portion co-extensive with the elongated dimension of thedonor housing is an agitator bar 28 which is fixed to this U-shapedmember.

As motive power is supplied to input shaft 18 th donor'- roller '12 and cam 20 are caused to rotate in the direction of the arrows. Rotation of cam 20 causes the U shaped member 22 to oscillate about a pivot point 24 which may be a suitable pin or other fastener to attach the arms 22 to end plates 6 of the housing. During a portion of each oscillation of U-shaped member 22 bar 28 presses inward on the flexible side wall or diaphragm 14. This results in moving the quantity of toner accumulated on this side wall into any cavities created by the donor rollers rotation and into contact with the donor roller for continued operation.

In the normal mode of operation the donor roller is I either moved continuously or moved in a periodic manner which results in the periodic and regular flexing of the diaphragm 14. This regular flexing maintains the sump of electrostatic marking particles in proper relationship with the donor roller for good donation to a developing applicator. While specific details and configuration of the donor housing of the present invention has been described, it

will become apparent to the person skilled in the art that the precise configuration of the donor housing may be altered without parting'from the principles of the present invention. For example, the side wall 10 instead of being made up of two non-coplanar members may lay within a single plane. v

In addition, while an elongated cylindrical member has been shown as the agitator bar 28 it will be recognized that other shapes and configurations may be employed with substantially the same result. It is only necessary to use a member which does not rupture the flexible diaphragm wall 14. In addition, while the agitator bar 28 has been disclosed as being only in contact with the flexible diaphragm 14 it will be readily realized that it may be molded into the diaphragm 14 or in some manner fixed thereto so as to positively act on this member during its complete motion.

Also, although the oscillating member 22 and associated bar 28 are described as being actuated by the donor rollers movement, it may be readily appreciated that the flexing of diaphragm 14 may be accomplished in other ways either as a function of the rotation of the donor roller or not. Furthermore, while a solid cylindrical donor roller has been used to aid the detailed description of the present invention, it should be apparent that donor members of other configurations are equally suited for use in the present invention. For example, natural fur or synthetic fibrous brushes maybe used.

While the inventionhas been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the invention.

What is claimed is:

1. A developing assembly comprising:

a. a developing applicator capable of rotation about a first axis; b. a donor member having an input shaft responsive to motive power to rotate said donor member about a second axis substantially parallel to said first axis; and, c. a sump housing adapted to contain a quantity of marking particles mounted about said donor mem-. ber, said sump housing having 1. an openingtherein to permit contact between said developing applicator and said donor member,

2. an end plate having an aperture through which said input shaft passes and which permits-said shaft to rotate relative to said end plate,

3. a side wall attached to said end plate and having a flexible portion, and 4. means responsive to rotation of said shaft for flexing said flexible portion.

2. A developing assembly as defined in claim 1 wherein said means includes a flexing member movable against said flexible portion.

3. A developing assembly as defined in claim 2 wherein said means includes a cam fixed to and for rotation with said input shaft and cam-following means responsive to the rotation of said cam and connected to said flexing member for oscillating said flexing mem ber against said flexible portion.

4. An assembly according to claim 1 wherein said donor member is supported in said sump housing closer to a wall of said housing opposite said side wall, and

wherein said flexing means is disposed for contacting said opposite wall.

5. A donor assembly comprising: spaced apart end plates, a bottom panel extending between said end plates and attached thereto,

aside wall attached to said bottom panel and said end plates, said side wall having a portion thereof constituting a rubber diaphram,

means for flexing said diaphram into the volume formed by said plates, panel and wall,

a donor member rotatably supported at least partially within said volume for contacting marking particles contained therein, and

means responsive to rotation of said donor member for effecting operation of said flexing means.

6.'An assembly according to claim 5 wherein said responsive means comprises a cam and follower arrangement operatively associating said donor member with said flexing means.

7. A developing assembly comprising:

a developing applicator,

a sump housing for containing a quantity of marking particles,

a donor member rotatably supported in said sump housing for transporting marking particles from said sump housing to said developer applicator, and

means responsive to rotation of said donor member for flexing one wall of said sump housing into the volume delineated by said sump housing.

Claims

1. A developing assembly comprising: a. a developing applicator capable of rotation about a first axis; b. a donor member having an input shaft responsive to motive power to rotate said donor member about a second axis substantially parallel to said first axis; and, c. a sump housing adapted to contain a quantity of marking particles mounted about said donor member, said sump housing having 1. an opening therein to permit contact between said developing applicator and said donor member, 2. an end plate having an aperture through which said input shaft passes and which permits said shaft to rotate relative to said end plate, 3. a side wall attached to said end plate and having a flexible portion, and 4. means responsive to rotation of said shaft for flexing said flexible portion.

2. an end plate having an aperture through which said input shaft passes and which permits said shaft to rotate relative to said end plate,

3. a side wall attached to said end plate and having a flexible portion, and

3. A developing assembly as defined in claim 2 wherein said means includes a cam fixed to and for rotation with said input shaft and cam-following means responsive to the rotation of said cam and connected to said flexing member for oscillating said flexing member against said flexible portion.

4. An assembly according to claim 1 wherein said donor member is supported in said sump housing closer to a wall of said housing opposite said side wall, and wherein said flexing means is disposed for contacting said opposite wall.

4. means responsive to rotation of said shaft for flexing said flexible portion.

5. A donor assembly comprising: spaced apart end plates, a bottom panel extending between said end plates and attached thereto, a side wall attached to said bottom panel and said end plates, said side wall having a portion thereof constituting a rubber diaphram, means for flexing said diaphram into the volume formed by said plates, panel and wall, a donor member rotatably supported at least partially within said volume for contacting marking particles contained therein, and means responsive to rotation of said donor member for effecting operation of said flexing means.

6. An assembly according to claim 5 wherein said responsive means comprises a cam and follower arrangement operatively associating said donor member with said flexing means.

7. A developing assembly comprising: a developing applicator, a sump housing for containing a quantity of marking particles, a donor member rotatably supported in said sump housing for transporting marking particles from said sump housing to said developer applicator, and means responsive to rotation of said donor member for flexing one wall of said sump housing into the volume delineated by said sump housing.