US3538994A

US3538994A - Apparatus for conveying toner particles

Info

Publication number: US3538994A
Application number: US778223A
Authority: US
Inventors: Roger G Olden
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1968-11-22
Filing date: 1968-11-22
Publication date: 1970-11-10
Anticipated expiration: 1987-11-10

Description

United States Patent [72] Inventor Roger G. Olden [56] References Cited y gg t Pennsylvania UNITED STATES PATENTS APPLN 778,2 1 I56 385 101915 w'n 198187 221 Filed Nov. 22, 1968 [45] Patented Nov. 10, 1970 Pnmary Examiner-Edward A. Sroka [73] Assignee RCA Corporation Attorney-Glenn H. Bruestle a corporation of Delaware [54] APPARATUS FOR CONVEYING TONER PARTICLES ABSTRACT. A

pparatus for conveying toner particles from a Drawing remote replenisher source to a main source where the toner [52] US. Cl 198/44, particles are consumed in a process comprises an endless belt ll8/637 and means to dispose it for rotation over the main source of [5 l Int. Cl B05b 5/02, toner particles. The belt is formed with a plurality of compart- B65g 47/44 ments and the replenisher source is disposed over the belt so [50] Field of Search 198/47, 53, that toner particles can fall thereon. Means are provided to 54, 56-57, 187, 44: 355/10(Horan); 118/637 (Feldman)(Kaplan): 222/57. 415(Lane) rotate. twist, and vibrate the belt over the main source so that toner thereon can fall into the main source to replenish it.

APPARATUS FOR CONVEYING TONER PARTICLES BACKGROUND OF INVENTION This invention relates to apparatus for conveying toner particles, and particularly to improved apparatus for conveying replenisher toner particles from a remote replenisher source to a main source of toner particles where they are consumed in a process. The improved apparatus for conveying toner particles is particularly useful in electrostatic printing apparatus wherein electrostatic images or charge patterns on an insulating surface are developed with toner particles.

In the electrostatic printing art, it has been proposed to develop an electrostatic image on an insulating surface by applying a developer mixture, comprising the toner particles and a carrier material therefor, to the electrostatic image. In this developing process, the toner particles are consumed but the carrier material is not. Consequently, the toner particles in the main source of developer mixture have to be replenished. It has been proposed to dispose a hopper with replenisher developers over the main source of developer mixture for replenishing purposes, but the space limitations in many compact machines preclude such an arrangement. Also, the distribution of the added replenisher developer in the developer mixture by such prior art arrangements is-usually uneven, necessitating elaborate developer mixing apparatus.

In the improved apparatus, the replenisher source of toner particles is disposed remotely from the main source of toner particles and the replenisher toner particles are conveyed to the main source in a manner to provide a relatively even distribution of the replenisher toner particles in the main source.

SUMMARY OF INVENTION The improved apparatus for conveying replenisher toner particles from a remote replenisher source to a main source comprises a belt supported by a pair of spaced-apart rollers so that a portion of the belt is disposed over the main source. The replenisher source is disposed to one side of the main source and over the belt so that replenisher toner particles can drop onto the belt. Means are coupled to the rollers to rotate them and to move and twist the belt so that the toner particles on the portion of the belt over the main source fall into the main source to replenish it.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective view ofone embodiment of improved apparatus for conveying toner particles from a remote replenisher source to a main source, some parts being broken away;

FIG. 2 is a longitudinal cross-sectional view of the improved apparatus shownin FIG. 1 formed by a vertical plane extending along the general direction of the arrow A; and

FIG. 3 is a cross-sectional view of the apparatus taken along the line 3-3 ofFIG. 2.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown improved apparatus for eonveying replenisher toner particles from a remote replenisher source, such as a hopper 12, to a main source of toner particles, such as a reservoir 14. The toner particles 16 in the reservoir 14 are used in a process for developing electrostatic images and charge patterns on an insulating surface 18 of a recording element 20, in a manner well known in the electrostatic printing art. The improved apparatus 10 is adapted to be a part of electrostatic printing apparatus wherein the recording element 20 is moved around a roller 22 that is disposed for rotation within the reservoir 14. The recording element 20, which may comprise a web of paper having thereon a photoconductive layer, such as zinc oxide, for example, is moved in the direction indicated by the

arrows

24 and 26 by any suitable means known in the art.

The toner particles 16 comprise pigmented particles whose average diameter may vary between 0.5 and 50 microns, for

example, and may be mixed with a carrier material such as iron filings, for example, to provide a triboelectric effect by which the toner particles 16 are provided with an electrostatic charge. In the process of tleveloplng electrostatic images on the recording element 20, the toner particles 16 are attracted to portions of the surface 18 of the recording element 20 in accordance with the polarity of the charge patterns thereon, and, consequently, the toner particles 16 in the reservoir 14 are consumed.

The toner particles 16 that are removed from the reservoir 14 are replenished by toner particles from the replenisher source toner particles 16 within the hopper 12, via a belt 30. The belt 30 is an endless belt formed with a plurality of compartments 32 such as provided, for example, by a rubber timing belt turned inside out. The belt 30 is disposed over a pair of spaced-

apart rollers

34 and 36 so that a portion 38 of the belt is disposed over, and across, the open reservoir 14. The roller 34 is a shaft disposed for rotation in bearings 40 and 42 that are fixed in space by any suitable means, as by the

adjustable gimbals

44 and 46. The

gimbals

44 and 46 and the reservoir 14 are .fixed to a base 47.

Means are provided to rotate the roller 34 about its axis so as to move, that is, rotate, the belt 30 over the

rollers

34 and 36. To this end, a pulley 48, fixed to one end of the roller 34, is coupled to a pulley 50, fixed to the shaft of a motor 52, addition said means of a belt 54.

The roller 36 comprises a pulley wheel disposed for rotation about its axis by means of a forked member 56. The forked member 56 is pivoted for rotation about the axis of a rearwardly extending horizontal shaft 60. The shaft 60 is journaled in a plate 62 which, in turn, is fixed to a wall 63 extending from the base 47. Thus, the axis of the roller 36 may be twisted in a vertical plane about the central point on the axis to twist the belt 30 in the space over the reservoir 14, as shown in FIGS. 1, 2 and 3. The roller 36 may be rotated that is, twisted, so that its axis forms any desired angle with the horizontal, and the roller 36 can be fixed in the twisted position by means of a 'set screw 64 adapted to engage and fix the shaft 60 in the plate 7 62. The angle through which the axis of the roller 36 is rotated about a point therein, with respect to a horizontal plane, can be indicated by a pointer 66 fixed to the forked member 56 and a graduated-scale 68 disposed on the wall 63 to cooperate with the pointer 66, as shown in FIG. 1.

The hopper 12 is formed with an opening 70 in the bottom thereof and is disposed slightly spaced from the upper surface of the belt 30 and to one side of the reservoir 14 by any suitable means, such as a bracket 72 fixed to the base 47, as shown in FIGS. 2 and 3. Thus, replenisher toner particles 16 within the hopper 12 can fall into the compartments 32 in the upper surface of the belt 30. A doctor blade 74, formed with a slot 76 therein, is adjustably mounted on one side of the hopper 12, as by a screw 78, as to limit the amount of the toner particles 16 that are conveyed on the belt 30 when the belt 30 is rotated in the directions indicated by the arrows 80 and 82, shown in FIG. 2. A horizontal plate 84, integral with the bracket 72, is disposed beneath the upper portion of the belt 30 and adjacent to the opening 70 of the hopper 12 so as to position the belt 30 with respect to the opening 70 and to maintain this portion of the belt substantially horizontal when the portion 38 of the belt 30 over the reservoir 14 is twisted.

Means are provided to vibrate the twisted belt 30 so that relatively sticky toner particles 16 in the compartments 32 of the belt 30 over the reservoir 14 will fall into the reservoir 14. To this end, an elongated resilient member has one end fixed to the forked member 56 and the other end in contact with the compartments 32 in the belt 30. With this arrangement, a vibratory motion is imparted to the belt 30 as it is rotated in the direction of the arrows 80 and 82, and toner particles 16 on the belt are shaken therefrom into the container 14, as shown in FIGS. 2 and 3. Another elongated member 92 can also be disposed over the belt 30 and spaced with respect to the member 90 so as to increase the vibratory motion of the belt if so desired.

The portion of the belt directly beneath the hopper 12 is maintained in a horizontal plane by resting on the plate 84. ln this manner the relatively small spacing between the surface of the belt 30 and the opening 70 in the hopper 12 is maintained fixed at all times. The angle through which the portion 38 of the belt 30 over the reservoir 14 is rotated, that is, the amount of twist, will depend upon the stickiness of the toner particles 16, When the toner particles 16 are relatively free flowing, the twist imparted to the belt 30, measured from a horizontal plane, will not be as great as it would be for relatively stickicr toner particles 16.

The operation of the improved apparatus in an electrostatic printing system of the type wherein a web of the recording element is moved continuously through the reservoir 14 and wherein toner particles 16 are consumed continuously in developing electrostatic images on the insulating surface 18 will now be explained. The motor 52 is energized and the roller 34 is rotated about its axis, thereby rotating the endless belt 30 in the direction of the arrows 80 and 82, as shown in FIG. 2. Toner particles 16 within the hopper 12 fall into the compartments 32 on the outer surface of the belt 30. The portion of the belt 38, between the horizontal plate 84 and the roller 36, is twisted transversely with respect to a horizontal plane by rotating the forked member 56, about its shaft 60, through a predetermined angle, as indicated by the pointer 66 and the scale 68. The

resilient members

90 and 92 contact the compartmented surface of the moving belt 30 and impart to it a vibratory motion which causes the toner particles 16 to fall from the belt 30 into the reservoir 14. Thus, replenisher developer 16 is supplied to the reservoir 14 to replenish the toner particles 16 that are consumed in the process of developing the electrostatic images on the surface 18 of the recording element 20.

The rate at which the toner particles is replenished is determined, in part, by the speed of rotation of the roller 34, and the spacing between the hopper l2 and the outer surface of the belt 30. The amount, that is, the height, of toner particles 16 upon the outer surface of the moving belt 30 is limited by the adjusted height of the doctor blade 74 from the surface of the belt 30. The distribution of the replenisher toner particles 16 that fall from the belt 30 to the reservoir 14 is relatively even across the reservoir 14. Additional mixing apparatus for mixing the replenisher toner particles 16 with the toner particles [6 in the developer mixture within the reservoir 14 is not shown but may be used if necessary in a manner well known in the art.

l. claim:

1. Apparatus for conveying toner particles comprising:

a. a toner particle dispensing hopper;

b. a reservoir spaced from said hopper for receiving said toner particles;

c. conveyor belt means disposed beneath said hopper and extending over said reservoir, said belt having a twist therein over said reservoir; and

d. means for moving said belt, whereby material deposited from said hopper onto said belt is carried to said reservoir where it is dumped from said belt.

2. ln apparatus of the type wherein toner particles from a reservoir of toner particles are consumed in a process, the improvementcomprising: v

apparatus for conveying toner particles from a remote replenisher source to said reservoir comprising:

a pair ofspaced-apart rollers;

a belt, said belt being disposed around said rollers so as to dispose at least a portion of said belt over said reservoir;

said replenisher source being disposed over said belt and to one side of said reservoir, whereby toner particles from said replenisher source may drop onto said belt;

and means coupled to one of said rollers to rotate it, whereby to move said belt over said rollers, said portion of said belt bein twisted transversely with respect to a horizonta plane over said reservoir, whereby toner particles on said belt can fall into said reservoir to replenish it.

3. ln apparatus of the type described in claim 2, said replenisher source comprising a hopper formed with an opening adjacent the bottom thereof, and said opening being adjacent to said belt.

4. In apparatus of the type described in claim 3, a doctor blade being adjustably fixed to said hopper adjacent to said opening therein, whereby to limit the amount of toner particles dispensed from said hopper to said belt.

5. In apparatus ofthe type described in claim 2:

said belt being an endless belt formed with a plurality of compartments for receiving toner particles therein from said replenisher source; and

means disposed adjacent said belt to contact said compartments and to impart a vibratory motion to said belt, when said belt is moving, whereby to shake toner particles from said belt into said reservoir.

6. ln apparatus of the type described in claim 2, means to twist said belt comprising means coupled to the other of said rollers to rotate it about a point in its axis through a predetermined angle with respect to a horizontal plane.

7. ln apparatus of the type described in claim 6, a pointer and indicia being cooperatively associated with said means coupled to said other roller to indicate said angle.

8. Apparatus for conveying toner particles to a reservoir of toner particles, said apparatus comprising:

a pair of spaced-apart rollers;

a belt, said belt being elongated over said pair of rollers with a portion of said belt disposed over said reservoir;

a hopper for replenisher toner particles disposed over said belt and to one side of said reservoir means coupled to one of said rollers to rotate it whereby to move said belt over said rollers; and

means including at least one of said pair of rollers to twist said portion of said belt over said main source transversely with respect to a horizontal plane.

9. Apparatus for conveying toner particles as described in claim 8, comprising, in addition:

said belt being an endless belt formed with a plurality of compartments in the outer surface thereof; and

said hopper being formed with an opening adjacent the bottom thereof, whereby replenisher toner particles from said hopper can fall into said compartments.

10. Apparatus for conveying toner particles as described in claim 9, comprising, in addition, a doctor blade being adjustably mounted on said hopper, adjacent said opening therein, to limit the amount of replenisher toner particles conveyed from said hopper to said belt when said belt is moving.

11. Apparatus for conveying toner particles as described in claim 8, comprising, in addition, said means to twist said belt comprising means to twist said one roller about a point in its axis of rotation through a predetermined angle.

12. Apparatus for conveying toner particles as described in claim 11, comprising, in addition, a pointer and a scale being cooperatively associated with said one roller to indicate said predetermined angle.

13. Apparatus for conveying toner particles as described in claim 9, comprising, in addition, at least one resilient member being disposed in contact with said compartments to vibrate said belt when said belt is moving, whereby to cause said replenisher toner particles to fall from said belt into said reservoir.