US3618867A

US3618867A - Toner replenisher device

Info

Publication number: US3618867A
Application number: US858988A
Authority: US
Inventors: Richard A Berlier; Dyer T Mccrory
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1969-09-18
Filing date: 1969-09-18
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09
Also published as: GB1309418A; FR2061774A1; CA939499A; JPS508939B1; DE2037557A1; FR2061774B1

Abstract

A toner replenisher unit for an electrostatic copying device. The toner particles are abraded off a solid toner block. Constant pressure is maintained between the toner block and the abrading roll throughout the consumption of the toner block by a spring acting through a ratio pulley, such that the spring force reduces as the weight of the toner block is reduced. Loading of the abrading roll is prevented by a brush which removes any toner particles. Toner particles, which do not freely fall from the brush, are removed by a brush wiper. Means are provided for accepting and positioning the toner block with an attached pallet so that the upper surface of the pallet is substantially parallel to a chord described by the edges of the surface ground into the toner block by the abrading roll.

Description

United States Patent Primary Examiner- Donald G. Kelly Atwrneys- Hanifin and Jancin and Maurice H. Klitzman ABSTRACT: A toner replenisher unit for an electrostatic copying device. The toner'particles are abraded off a solid toner block. Constant pressure is maintained between the toner block and the abrading roll throughout the consumption of the toner block by a spring acting through a ratio pulley, such that the spring force reduces as the weight of the toner block is reduced. Loading of the abrading roll is prevented by a brush which removes any toner particles. Toner particles, which do not freely fall from the brush, are removed by a brush wiper Means are provided for accepting and positioning the toner block with an attached pallet so that the upper surface of the pallet is substantially parallel to a chord described by the edges of the surface ground into the toner block by the abrading roll.

PATENTEDunv 9 l97l SHEET 1 BF 2 INVENTORS RICHARD A. BERLIER DYER T. MCCRORY TONER REPLENISHER DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to electrophotographic chemistry, process and materials, and more particularly, apparatus for producing document copies.

2. Description of the Prior Art The process of electrostatic copying involves evenly coating a plate formed of a photoconductive insulating material with electrostatic charges. The photoconductive insulating material is then exposed to the subject matter to be reproduced by a conventional imaging technique. This exposure discharges the electrostatic voltage on the plate in proportion to the amount of radiation striking any particular portion of the plate. After the exposure there remains on the plate electrostatic charges forming a latent image of the subject matter imaged onto the plate.

The latent image is developed by cascading over the plate a charged finely divided dark-colored thermoplastic powder, hereinafter referred to as toner. Generally, before the toner is cascaded over the exposed photoconductive insulating plate, the toner is combined with a granular carrier material. This material more evenly distributes the electrostatic charge among the toner particles and provides for easier transport of the toner particles to and over the electrostatic plate.

After the latent image has been developed by the toner particles, the image, in the form of the toner particles, is transferred to a sheet of paper. The toner particles are then fixed" to the paper by a fusing element. It is seen that as the process continues, toner particles are consumed and must be replaced.

in most prior art devices the replenishing toner is provided in powdered form. This toner is placed into a compartment from which it is removed in carefully metered quantity to be combined with the granular carrier particles. Not only is it difficult for an operator to load the compartment with the toner, but it is inherently messy. The fine particles of toner form a black cloud when being poured into the compartment and, more often than not, soil both the electrostatic copying device and the operator.

Further, metering the correct quantities of toner particles from the storage compartment is a complicated and exacting task. Prior art devices have gone to great lengths to insure that the correct amount of toner particles are metered. If too many particles are metered, the eventual image will be too dark and contain the fused black toner particles in undesired locations. If too little is metered, the full latent electrostatic image will not be developed.

in order to overcome these objections a few prior art devices have used toner in block form. These toner blocks are usually prepared by mixing the original finely divided powder with well-known bonding agents and then subjecting the material to pressure. There are other well-known methods of forming such toner blocks.

The prior art devices using toner blocks, rather than metering toner from the compartment in which it is stored, remove the toner particles from the blocks in the desired amounts, usually by abrasive techniques. However, these latter prior art devices suffered from numerous faults. First, many were not adjustable. That is, the operator of the electrostatic device could not adjust the quantity of toner particles to be removed from the toner block.

Other devices were adjustable, but in adding this feature so complicated the mechanism for removing the toner particles, as to make the device commercially unfeasible.

Further, whether adjustable or not, the prior art devices, as the toner block was consumed, removed varied amounts of toner. That is, the amount of toner removed from the toner block is proportional to the force with which the toner block presses against the removing member (generally an abrading roll). Most prior art devices use spring pressure to maintain this force between the toner block and the abrading roll. As is well known to those skilled in the art the force exerted by a spring is proportional to its extension. Thus, as the block was consumed, the springs extension changed and so did its force. With this change in the force exerted by the spring there was a proportional change in the force between the toner block and the abrading roll. The net result was a constantly varying amount of toner production.

Prior art devices using toner blocks encountered vibrations and chatter when the grinding roll removed the toner. This damages and chips the block and effects the toner replenishing rate.

Also, the prior art devices using toner blocks did not contain convenient loading mechanisms. Generally, the toner block had to be carefully mounted ontothe mechanism which urged it into contact with the abrading means. This necessitated that the operator acquire skill in loading the electrostatic copying device. Further, it was a time-consuming operation.

Other prior art devices had difficulty, after removing the toner particles from the toner block, in making them available for developing the latent image. For example, often the toner particles would lodge in the abrading roll; thereby clogging the abrading roll removing those particles from further use and, in some cases, causing a deterioration of the abrading function.

Therefore, it is an object of this invention to provide an improved toner replenisher unit which does not necessitate powdered toner.

It is another object of this invention to provide an improved toner replenisher unit which utilizes toner in a compressed block fonn.

it is another object of the invention to provide force means for removing a constant amount of toner from the toner block, notwithstanding the amount of toner that has already been removed.

it is another object of the invention to provide such force means in an economical and easily fabricated mechanism.

It is another object of the invention to provide means compatible with maintaining a constant pressure for removing toner particles from a toner block in adjustable quantities.

it is another object of the'invention to reduce chatter while removing particles from the toner block.

it is another object of this invention to provide means for easily loading the toner block.

Lastly, it is an object of this invention to completely remove all particles from the abrading means so that they can be utilized in developing the latent image.

SUMMARY OF THE INVENTION in accordance with the above objects, the present invention provides a spring or equivalent (such as pneumatic or hydraulic means) exerting a mechanical force to urge the toner block to contact the grinding (abrading) rolls with a constant pressure. This power supply comprises a spring held in tension. The amount of extension of this spring is adjustable by a selflocking worm and gear arrangement through a cable takeup pulley. Because of the cable takeup pulley, a large turn of the worm gear by the cranking handle, causes a small change in the pressure between the toner block and the grinding roll. The spring exerts its pressure on the toner block through a ratio pulley. The ratio pulley prevents large changes in the extension of the spring; thereby, insuring that the force of the block against the abrading rolls is substantially constant.

The invention provides for easy loading of the toner block by allowing the placement of the toner block in its storage compartment with an attached pallet. The operator has only to slip the adapting slot on the pallet onto a shaft provided in the toner block compartment. Further, when the front wall of the compartment is closed, an additional pressure is placed upon the block forcing it into correct engagement with the grinding roll.

When the pallet has assumed its correct position in the toner block compartment, the upper surface of the pallet is substantially parallel to the surface ground into the toner block by the grinding roll. This allows the grinding roll to remove all the possible toner from the pallet.

A brush removes the particles embedded in the grinding roll making available for development all toner particles removed from the toner block and preventing the clogging of the grinding roll. Further, any particles that might have lodged in the brush, are removed by a brush wiper.

Thus, the invention meets all the above objects with an uncomplicated, easily fabricated, and economically feasible toner replenisher unit.

BRIEF DESCRIPTION OF THE. DRAWINGS The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiment of the invention as illustrated in the accompanying drawings.

FIG. 1 is a diagrammatical representation of the preferred embodiment of the invention.

FIG. 2 is a side view of the grinding roll and toner bloclt support mechanism.

DETAILED DESCRIPTION OF THE DRAWINGS In order to control the force with which toner block 43 is urged against grinding roll 45, a control means is provided. Referring to FIG. I the control means is seen to comprise a cranking handle ll onto which is mounted a worm gear 3. Worm gear 3 engages gear 5. Worm gear 3 and gear 5 form the well-known self-locking worm gear assembly. Gear 5, indicator wheel 9, and cable takeup pulley II are affixed to indicator shaft 7. Permanently amxed to the circumference of cable takeup pulley II is one end of cable 113. The other end of cable 13 is connected to power spring l5 after contacting pulley 17. The other end of power spring I5 is attached to pin 19. Pin 19 is permanently affixed to lever Ell. Also connected to pin 19 is cable 23. Cable 23 winds around pulley 25 and is attached to hub 27 on ratio pulley 29.

The power means of the invention is thus composed of devices indicated by reference numbers lid-29. Ratio pulley 29 prevents large movements in power spring and thus, acts in the maintenance of a constant pressure between toner block 43 and grinding roll 45.

Permanently attached to the large circumference of ration pulley 29 is the linkage means composed of

cables

31 and 33. Cable 31 contacts pulley 35 before its other end is attached to one end of shaft 39; cable 33 contacts pulley 37 before its other end is attached to the other end of shaft 39. Shaft 39 supports easily removable pallet dll onto which is permanently attached toner block 483. Under the urging of power spring 15 and connecting

cables

23, 31 and 33, toner block 43 is forced into contact with grinding roll 45.

In order to utilize all the toner present in the toner block 43 a brush 47 is in contact with grinding roll 45; and in contact with brush 47 is brush wiper d9. It is seen that grinding roll l5 in the preferred embodiment is composed of many sharp toothlike projections around its circumference, much in the nature of a ratchet. Brush d7 wipes grinding roll 45 cleaning any accumulation of toner particles that have lodged in grinding roll 45. In turn brush wiper 39 cleans the accumulated particles from brush 47. Thus, there are substantially no toner particles left in grinding roll or brush 47. Since no particles are lost, this also maintains a constant quantity of toner production.

Lever 21 rotates on pin 5i. Lever 21 can be rotated from the normal position as shown in FIG. I to a position so that its trailing edge engages extension 53 on latch 55. When lever 21 so engages latch 55 tension is removed from cable 23 allowing shaft 39 to lower under its own weight. The pallet of the used toner block 43 can then be removed from shaft 359 and a new toner block and attached pallet can be inserted.

Referring now to FIG. 2 a side view of the lower portion of FIG. 1 is shown. In addition to the structure shown in FIG. 11, FIG. 2 shows the compartment or housing in which pallet 41 and toner block 4131 move. This housing is composed of sidewalls 557, back wall 59, and front wall at. Sidewalls 57 each have a guide 63 in which shaft 39 travels. Front wall 61 is pivotably mounted onto sidewalls 57 by screws 65. When front wall an is opened, pallet All and the attached toner block 33 can be mounted upon exposed shaft 39. As can be best seen from FIG. 2, pallet 41 mounts onto shaft 39 by merely slipping pallet dll onto shaft 39. Shaft 39 engages a slot 40 in pallet 41.

Also shown in FIG. 2 is a spring 67 attached to wall 69 (wall 69 is a part of the rest of case enclosing the entire copier). Spring 67 positively engages the upper portion of toner block 43 forcing toner bloclt 43 toward rear wall 59. Spring 67 is ad ditionally forced against toner block 43 under the urging of front wall till. Rear wall 59 may have supporting strips attached thereto preferably composed of a low-friction coefficient material such as nylon or Teflon. Attached to the lower portion of wall 59 is a deflector plate 71. Deflector plate 71 deflects the toner particles ground from toner block 43 into a sump, not shown, for accumulating both the toner material and carrier particles.

It has been found that if the toner block is set slightly off of the centerline of the grinding roll, chatter and chipping of the toner block is minimized. That is, by positioning the toner bloclt so that the grinding roll preferably grinds the toner block, at an angle substantially as shown, chatter and chipping of the toner block is reduced. This minimizes the tendency to chip the exit edge of block 43 as the teeth of roll 45 move out of contact with the top surfaces of block 43. This can best be seen in FIG. 2.

This is in contrast to the ordinary situation where the center of the toner block is an extension of a radius of the grinding roll. In the ordinary situation half of the grinding roll in contact with the toner block grinds down into the toner block and the other half of the grinding roll grinds up and out of the toner block.

However, when the toner block is offset from a radius of the grinding roll, the grinding roll is enabled to remove almost all of the toner block from the pallet. This is possible because the surface plane of the pallet is parallel to a chordal plane formed by the connections of edges 42 and 44 of the toner block 43 in FIG. 2.

Also seen in FIG. 2 is the relationship described above between grinding roll d5, brush 417, and brush wiper l9.

OPERATION OF Tit-IE INVENTION Cranlting handle ll is turned depending upon the amount of toner particles desired. That is, turning cranking handle I increases or decreases the tension in power spring 15 through worm 3, gear 5, shaft 7, cable talteup pulley II, and cable 13. Through cable 23, ratio pulley 29,

cables

31 and 33, and shaft 39 pallet di and toner block d3 are urged into contact with grinding roll 45'. The greater the tension present in power spring 15, the greater the force with which toner block 43 is urged against grinding roll did. The more pressure between toner bloclt 413 and grinding roll 45, the more toner particles grinding roll 45 removes from toner block 43.

Indicator wheel 9 has numeric indications representative of a range of force exerted by power spring 15, and thus, indirectly indicates the amount of toner particles removed from toner bloclt 4335. As an example, a setting of 0 may produce minimum toner replenishing while a setting of 5" may produce maximum replenishing.

The foregoing arrangements permit the selection of any of a number of desired grinding (consumption) rates. Within a predetermined range while maintaining the speed of the grinding roll constant.

The particles ground off toner block 43 either fall from grinding roll 45' or are removed from grinding roll 45 by brush 47. The particles that do not freely fall from brush 47 are removed by brush wiper 49. All the particles fall into the toner and carrier sump (not shown) either directly or after being deflected by deflector plate 71.

To load a toner block 43 with the attached pallet 41, lever 2! is rotated to the right so that its trailing edge engages extension 53 on latch 55. This removes the tension from cable 23, allowing shaft 39 to fall under its own weight. Front door 61 is pivoted downwardly, exposing the interior of the compartment in which pallet 41 travels. The depleted toner block 43 with its pallet 41 is removed, and a new toner block 43 with its attached pallet 41 is inserted onto shaft 39. Front wall 61 is pivoted upwardly enclosing the compartment and additionally urging spring 67 against the toner block causing the toner block to rest against rear wall 59. The angle to the horizontal which pallet 41 assumes permits grinding roll 45 to almost completely remove all toner material mounted upon pallet 41.

As the toner block 43 is consumed, its weight decreases and spring shortens due to the shortening of the block 43. The spring force decreases with any decrease in its deformation and if the system is properly dimensioned the net changes in weight and spring force offset each other. This yields a net force exerted by the abrading roll 45 on the toner block 43 that remains substantially constant. This net force will be proportional to the force required to extend the spring 15 to a position such that the ends of

cables

31 and 33 are at their uppermost point of travel.

The proportionality of the force of the roll 45 against the block 43 is determined by the relation of the radius of hub 27 to the radius of the large hub of ratio pulley 29. Any change in pressure between roll 45 and block 43 is directly effected by the dividing effect of the ratio pulley 29 on the force exerted by spring 15 for any change of setting of indicator wheel 9.

One skilled in the art will see from the above description and the drawings that there will be an insignificant pressure change between the block and the grinding roll over the distance while pallet 41 moves for any selected guide number on the indicator wheel 9. This tension in power spring 15 results in a constant pressure being applied between grinding roll 45 and toner block 43. Therefore, this aspect of the invention allows a constant pressure to be applied between toner block 43 and grinder roll 45 throughout the entire movement of pallet 41 and consumption of toner block 43 without necessitating a resetting of cranking handle 1.

As block 43 is consumed its weight decreases in a linear fashion, the length of spring 15 decreases thereby decreasing the force it exerts, and the arrangements just described therefore provide an automatic compensation to insure that a constant pressure between block 43 and roll 45 is substantially maintained throughout. the consumption process.

Lastly, because of brush 47, brush wiper 49, and deflector 71, it is seen that all toner particles are forced to fall into toner and developer sump (not shown). Through proper dimensioning of the apparatus particles can be prevented from falling back into the compartment in which is located toner block 43. This not only allows all toner particles to be used for developing the latent image, but also maintains the clean lines of the toner storage compartment. The latter advantage allows an operator to change the toner block without fear of soiling himself.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

We claim:

1. A toner replenisher unit providing particles from a solid toner block including:

force means for supplying a stable mechanical force including a spring and a ratio pulley comprising an inner hub and a large outer hub, the said inner hub connected to said spring and said outer hub connected to a linkage;

control means for variably setting the force supplied by said force means;

grinding means for removing particles from said toner block;

said linkage connected to said force means for forcing said toner block against said grinding means with a constant pressure.

2. A toner replenisher unit providing particles from a solid toner block comprising:

a spring;

control means for varying the extension of said spring;

a ratio pulley comprising an inner hub and an outer hub, the

inner hub connected to said spring;

linkage means for urging a toner block into contact with a grinding means for removing particles from said solid toner block, and said linkage means connected to the outer hub of said ratio pulley maintaining a constant force between said toner block and said grinding means.

3. A device as in claim 1 including power release means for extending said spring to its fullest extension causing said linkage means to move said toner block away from said grinding means.

4. A device as in claim 3 wherein said linkage means includes a shaft for supporting a removable toner block with an attached pallet.

5. A device as in claim 4 wherein said grinding means grinds substantially down into said block so that the upper surface of said pallet is substantially parallel to the chordal plane of the surface ground into said toner block by said grinding means.

6. A device as in claim 4 including:

brush means for removing the particles from said grinding means; and

brush wiper means for removing the toner particles from said brush means.

7. A device as in claim 1 wherein said control means includes:

handle means;

a self-locking worm and gear means connected to and controlled by said handle means;

a shaft on which said gear means is mounted;

indicating means mounted on said shaft;

cable takeup means mounted on said shaft; and

a cable connected to the periphery of said cable takeup means and to said spring means for controlling the extension of said spring means according to the movement of said handle means.

8. A toner replenisher unit providing particles from a solid toner block including:

grinding means for removing particles from said solid toner block;

brush means for removing the means; and

brush wiper means for removing the toner particles from said brush means and deflecting the toner particles away from the toner block.

9. A device as in claim 2 wherein the means included in said linkage means is a shaft which supports a pallet, said means supporting said pallet and toner block with said grinding means grinding substantially down into said toner block so that said pallets upper surface is substantially parallel to the surface ground into said toner block by said grinding means.

particles from said grinding

Claims

1. A toner replenisher unit providing particles from a solid toner block including: force means for supplying a stable mechanical force including a spring and a ratio pulley comprising an inner hub and a large outer hub, the said inner hub connected to said spring and said outer hub connected to a linkage; control means for variably setting the force supplied by said force means; grinding means for removing particles from said toner block; said linkage connected to said force means for forcing said toner block against said grinding means with a constant pressure.

2. A toner replenisher unit providing particles from a solid toner block comprising: a spring; control means for varying the extension of said spring; a ratio pulley comprising an inner hub and an outer hub, the inner hub connected to said spring; linkage means for urging a toner block into contact with a grinding means for removing particles from said solid toner block, and said linkage means connected to the outer hub of said ratio pulley maintaining a constant force between said toner block and said grinding means.

6. A device as in claim 4 including: brush means for removing the particles from said grinding means; and brush wiper means for removing the toner particles from said brush means.

7. A device as in claim 1 wherein said control means includes: handle means; a self-locking worm and gear means connected to and controlled by said handle means; a shaft on which said gear means is mounted; indicating means mounted on said shaft; cable takeup means mounted on said shaft; and a cable connected to the periphery of said cable takeup means and to said spring means for controlling the extension of said spring means according to the movement of said handle means.

8. A toner replenisher unit providing particles from a solid toner block including: grinding means for removing particles from said solid toner block; brush means for removing the particles from said grinding means; and brush wiper means for removing the toner particles from said brush means and deflecting the toner particles away from the toner block.