US3493269A - Loading head - Google Patents

Description

Feb. 3,-1970 P. J. KAVENY 3,493,269

LOADING HEAD Filed Jan. 3, 1967 2 Sheets-Sheet l INVENTOR. r PAUL J. KAVENY A TTORNEY P. J; KAVENY 3,493,269

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United States Patent 3,493,269 LOADING HEAD Paul J. Kaveny, Rochester, N.Y., assignor to Xerox Corporation, Rochester, N.Y., a corporation of New York Filed Jan. 3, 1967, Ser. No. 607,001 Int. Cl. A4611 9/02 U.S. Cl. 30017 9 Claims ABSTRACT OF THE DISCLOSURE Apparatus for supporting, advancing, and indexing a cylindrical brush which is to be sheared. The brush is delivered to the work zone of a shearing machine where means are provided to position the hair fibers in a substantially straight radial posture so that they can be sheared to produce a brush having a symmetrical outer periphery.

This invention relates to apparatus for delivering a cylindrical brush to the work zone of a shearing machine.

More specifically, this invention relates to a loading head for delivering a core mounted xerographic cleaning brush to the work zone of a shearing machine or the like. In the process of xerography, a plate, comprising a photoconductive insulating coating which is placed upon a conductive backing, is charged uniformly and the photoconductive surface then exposed to a light image. The photoconductive coating becomes conductive under the influence of the light so as to selectively dissipate the electrostatic charge found thereon/or therein to produce a latent image. The latent image is then developed by means of a variety of pigmented resins which have been specifically developed for this purpose. The resins or toner are electrostatically attracted to the latent image on the photoconductive surface in proportion to the amount of charge found thereon/or therein so that areas of small charge concentration become areas of low toner density while areas of greater charge concentration become proportionally more dense. The developed latent image can then be transferred to a support material and permanently affixed thereto.

Transfer of a developed latent image is usually effected by a corona generating device which im arts an electrical charge sufficient to attract toner particles from the photoconductive surface to a support material, the magnitude of the charge required to effect transfer being dependent upon many variables. It has been found, however, that some residual developing material will remain behind after this transfer is effected. That is, although the electrostatic transfer forces applied to the support material effects transfer of a predominance of the developed image, some toner particles possessing a higher magnitude of forces will remain on the photoconductive surface. A common method of removing this residual toner from a xerographic plate is to treat the xerographic plate with a cleaning brush after the transfer operation is completed, the brush usually being moved rapidly over the plate surface to produce cleaning.

Generally, a xerographic cleaning brush is formed by placing a natural or a synthetic fur fiber over a core material to form a cylindrical brush. The brush is then mounted in close poximity to the photoconductive sur face so that a predetermined amount of interference exists between the hair fibers and the photoconductor. Rotating the brush at relatively high speeds causes the hair fibers to be flicked against the photoconductive surface thereby effecting removal of residual toner by mechanical as well as triboelectrical means. For further information concerning a suitable apparatus for cleaning a photoconductive surface, reference is had to Turner and Mayor Patent No. 2,751,616.

3,493,269 Patented Feb. 3, 1970 Cylindrical core mounted brushes, such as those used in paint rollers or the like, are oftentimes fabricated from synthetic pile fabrics or natural furs which have been suitably treated and sheared in a flat condition, the flat fabric then being glued to the core material to .give the 'brush the desired form. However, it has been found that mounting a pretrimmed fabric on a core often times produces a non-uniform brush because of the many uncontrolled variables encountered in the mounting process. For example, uneven gluing or non-concentric cores result in the brush having a non-uniform outer periphery, that is, the distance from the center of the brush to the outer extremities of the hair fibers will vary. Such a brush is unsuitable for use in the xerographic cleaning process. The portion of the brush having short hair fiber extension will not be able to engage the residual powder on the photoconductive surface and therefore will not produce the desired cleaning. On the other hand, the portion of the brush having excessively long hair fibers will be wiped across the photoconductive surface thereby causing abrasion of the photoconductive surface. It has therefore been found advantageous to shear a cylindrical cleaning brush after core mounting in order to produce a more uniform outer surface. However, handling and delivering a core mounted cleaning brush to a shear has proven difficult because of the tendency of the hair fibers to bend or curl during the shearing operation. That is, the relatively weak unsupported hair fibers of the brush are delivered to the shear in a non-uniform random posture resulting in a non-uniform brush being produced. The loading and indexing of a cylindrical brush into a shear has also proven time consuming and costly because these operations must be either performed by hand or by complicated mechanisms which require frequent checking and adjusting. That is, valuable machine time is lost during the loading and positioning of a work element in the shearing machine.

It is therefore an object of this invention to improve apparatus for supporting and delivering a cylindrical brush into the work zone of a shearing machine.

Another object of this invention is to provide apparatus for delivering a cylindrical brush to the work zone of a shearing macrine with a minimum loss of machine time.

A further object of this invention is to provide apparatus for delivering a cylindrical brush to work zone of of a shearing machine with the hair fibers of the brush in a uniform extended posture.

These and other objects of this invention are attained by a rotatably mounted loading head for supporting, advancing, and indexing a cylindrical brush which is to be sheared. The brush is delivered to the work Zone of a shearing machine where it is spun at relatively high speeds to force their hair fibers in a substantially straight radial direction so that the fibers can be sheared evenly to produce a brush having a uniform outer periphery.

For a better understanding of this invention, as well as other objects and further features thereof, reference is had to the following detailed description of the invention to be read in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of the loading apparatus of the present invention;

FIG. 2 is a partial view of the apparatus taken along lines 22 of FIG. 1; and

'FIG. 3 is a sectional view of the apparatus taken along lines 3-3 of FIG. 2.

In many automatic xerographic machines, the photoconductive plate is fabricated in the form of a drum, the drum being adapted to pass repeatedly through the various xerographic processing stations. To remove residual toner remaining on the drum after transfer of a developed xerographic image, a cylindrical shaped cleaning brush is mounted in close proximity to the drum so that some interference exists between the photoconductive surface to be cleaned and the brush fur fibers. The cylinder is supported on both ends by a truncated cone-shaped insert adapted to grip the cylinder for rotation therewith, one of the inserts being motor driven and adapted to rotate the cylindrical brush. An extremely light pressure is applied to the photoconductive surface of the xerographic plate by the rotating brush to dislodge any residual powder that may be adhering thereto. For further information concerning a suitable automatic xerographic apparatus employing a cylindrical cleaning brush as herein described, reference is had to Mayo et al., Patent No. 3,062,109.

A cylindrical cleaning brush is supported in the apparatus of the present invention in much the same manner as it would be supported in an automatic xerographic machine. As shown in FIG. 1, cylindrical brushes 10, depicted in dotted lines, are positioned in a loading and unloading station (station A) and a work station (station B). Loading frame 12 comprises a cylindrical hub 13 upon which is rigidly affixed two U-shaped members 14 capable of supporting a rotary brush therebetween. Running coaxially with, and extending through, hub 13 is shaft 15 which is mounted in bearings (not shown) located in vertical support frame members 16 and 17. The entire support frame 12 is free to rotate about shaft 15 so that an unsheared brush loaded in station A is advanced to work station B. At the same time, a brush which has been treated in the work station is once again brought back to a position where it can be unloaded.

Referring now to FIG. 3, a brush 10 is shown being supported in U-shaped member 14 between rotatable truncated cone- shaped arbors 18 and 19. Shaft 50, upon which arbor 18 is slidably mounted, passes through housing 52 and is securely jonrnaled in bearing hub 55 by means of bearings 51, the hub, in turn, being rigidly affixed to U-shaped frame 14. A recess 60 machined in housing 52 enables arbor 18 to move freely therein along guide pin 53. The pin is securely seated in housing 52 and provides a means to properly position the arbor as it moves back and forth in a lateral direction. Spring 54, also seated in housing 52, urges arbor 18 outwardly towards cylindrical brush l0. Truncated cone-shaped arbor 19 is similarly positioned in the opposing arm of U- shaped member 14 so that a cylindrical brush may be supported therebetween in substantially parallel relationship with cylindrical hub 13 (FIG. 1). Arbor 19 is permanently afiixed to shaft 57 by means of set screw 58, the shaft being journaled in hub 55 by means of bearings 51. Keyed to the opposite end of shaft 57 is an electromagnetic clutch plate 61 adapted to engage an electromagnetic clutch or brake. To load or unload a cylindrical brush between arbors 18 and 19, movable arbor 18 is moved back against the biasing force of spring 54 enabling a core mounted brush to be slipped over the stationary truncated cone-shaped arbor 19. Arbor 18 is then allowed to slide laterally along shaft 50 into the core whereby the brush is supported between the rotatable arbors.

As shown in FIG. 2, a hydraulic driving unit 20 supplies the necessary force to rotate the loading frame 12 so that a brush in the loading and unloading station is advanced to the work station while a brush which has been sheared is returned to a position where it can be unloaded from the apparatus. Drive unit 20 comprises a housing 21 in which a cavity 22 is formed. A drive shaft 25 is centered in the cavity and fits snugly against embossed section 28 extending from the main housing 21. Vane 27 is permanently afiixed to shaft 25 and runs the entire length of the cavity opening to divide the cavity into two separate chambers. Rotation of the shaft is obtained by introducing hydraulic fluid under pressure through intake-exhaust port 31 causing the fluid to exert pressure against vane 27 to drive the shaft in a direction from stop 29 towards stop 30-. Introduction of hydraulic fluid through opposing intake-exhaust port 32 reverses the direction of shaft rotation. Fluid is supplied and returned from a reservoir (not shown) through hydraulic connectors 33 and 34 mounted in main housings 21. Drive units similar to the one herein described are commercially available from the Rotac Torque Actuator, Division of Ex-Cell-O Corporation, Detroit, Michigan. Drive unit 20 is affixed to support member 37 (FIG. 2) which is mounted on a base plate 38. Drive shaft 25, which extends through housing 22, has a drive sprocket (not shown) rigidly mounted thereon. The drive sprocket rotates loading frame 12 by means of sprocket 40 acting through chain 41.

In operation, a brush is mounted between arbors 18 and 19 in U-shaped member 14 which is positioned in the loading and unloading station (station A). The brush is then advanced toward the work station (station B) by rotating the loading frame 12 about shaft 15; rotation being accomplished by means of hydraulic drive unit 20 acting through frame sprocket 40. On each of the main supporting members 16 and 17 is afiixed a pair of mounting blocks 42 and 43 in which stops 45 are adjustably seated. Also mounted on the two arms of one of the U- shaped members making up the loading frame 12 are pads 47 (FIG. 3) which are positioned to encounter the adjustable stops 45 as the frame moves between stations. The hydraulic drive unit rotates the frame until the advancement of the pads is interrupted by the stops. At this time, the drive unit continues to deliver a rotational force to the frame thereby forcing the frame securely against the stops. Indexing a brush, the brush already being located at a predetermined distance from the axial center line of the frame, is accomplished by adjusting stops 45 to place the brush at a desired position in reference to the shearing apparatus.

In the present invention, the hair fibers of a cylindrical brush are presented to the shearing apparatus or the like at the work station in a uniform radial direction so that the hair fibers may be evenly sheared to produce a brush having a uniform outer periphery. Presenting the hair fibers to the shear in this uniform posture is made possible by spinning the cylindrical brush, the brush being rotatably mounted between arbors 18 and 19, at relatively high speeds. The centrifugal force created by the high speed spin is such as to force the individual hair fibers outwardly in substantially a uniform radial direction. Referring once against to FIG. 1, an electromagetic clutch 70 is shown positioned in work station A adjacent to clutch plate 61. The electromagetic clutch is normally positioned out of the path of travel described by the spring biased clutch plate as the plate moves in an arcuate path between stations. Energizing the electromagnetic clutch creates a flux field of sufi'icient force to pull the biased clutch plate 61 into contact with the clutch 70. A motor MOT'I is directly coupled to the electromagetic clutch and provides the necessary force to spin a brush mounted in the work station at a relatively high speed.

Upon the completion of the shearing operation, the above-mentioned procedure is reversed by introducing hydraulic fluid into the hydraulic drive unit through intake and exhaust port 32 (FIG. 2) thereby causing the loading frame to swing back so as to place the sheared brush once again in the loading and unloading station where it can be removed from the loading frame. It has been found advantageous to return the brush to the unloading position as rapidly as possible to minimize lost machine time. A magnetic brake is supported in the loading and unloading station on support arm 73 to brake the freely spinning cleaning brush mounted between the rotatable arbors which has been returned to the unload station.

Brushes which have been shipped or stored for long periods of time in one position become matted or curled, that is, the hair fibers are forced into positions whereby they assume an unnatural set. The hair fibers are oftentimes in a condition that the brush must be rotated at extremely high speeds in order to unmat the hair fibers, speeds, in fact, which would move the hair fibers so rapidly through a shear that they could not be trimmed. It is possible in the present invention to mount a motor in the loading station similar to that shown positioned in the work station in FIG. 1; the motor acting through brake 75 to pre-spinning a matted cylindrical brush at extremely high speeds prior to its delivery to the Work station. It has been found that a first pre-spinning of the brush at relatively high speeds will condition the hair fibers so that they can later, upon delivery to the work station, be made to assume a radial posture at lower rotational speeds, that is, speeds at which the hair fibers can be properly sheared. It has been found that pre-spinning a brush as herein described at a speed in excess of 3,000 rpm. will satisfactorily remove the unwanted curl therefrom.

While the invention has been described with reference to the structure disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the scope of the following claims.

What is claimed is:

1. Apparatus for advancing a cylindrical brush to a work station including a frame,

a loading head journaled for rotation in said frame, said loading head comprising a cylindrical hub having mounted in opposed relation thereon two bifucated support members, each support member being adapted to support a cylindrical brush therein in substantially parallel relation with the hub,

said support members being positioned upon Said hub to support simultaneously cylindrical brushes in a loading station and a work station,

drive means for rotating said loading head to advance a brush supported in the loading station towards the Work station,

indexing means positioned in the work station to interrupt the advancement of said loading head at a predetermined position in the work station,

means positioned in said work station being arranged to coact with said support members to rotate a brush supported in the work station at a speed sufiicient to force the brush fibers outwardly in a substantially radial direction, and

means operable to reverse the direction of said drive means whereby the brush in the work station is returned to the loading station.

2. The apparatus of claim 1 wherein said indexing means comprises an adjustable stop for positioning the axial centerline of the cylindrical brush supported in the work station at a predetermined position.

3. The apparatus of claim 2 wherein the cylindrical brushes are supported between truncated cone-shaped arbors rotatably mounted in the arms of said support members, one of the truncated cone-shaped arbors being operably connectable to said brush rotating means by an electromagetic clutch.

4. The apparatus of claim 3 having further means to retard the rotation of a cylindrical brush returned to the loading station, said retarding means comprising an elec- 6 tromagnetic brake being positioned adjacent to the load ing station and being adapted to engage said one truncated cone-shaped arbor.

5. The apparatus of claim 3 having a second brush ro ating means positioned in the loading station for rotating a brush supported therein at a speed greater than the speed of rotation maintained in the work station.

6. The apparatus of claim 5 Wherein a brush located in the loading station is rotated at a speed in excess of 3,000 revolutions per minute.

7. Apparatus for advancing and supporting a cylindrical brush in a Work station including a support frame,

a loading head rotatably supported in said frame including an elongated hub journaled for rotation in the frame having two bifurcated members afiixed thereto for supporting a pair of cylindrical brushes in substantially parallel relation with the hub,

said support members being positioned on the hub to simultaneously support a brush in a loading Station and a brush in a work station,

drive means for rotating said loading head about the hub to advance a brush in the loading station to the work station,

indexing means positioned in the work station for interrupting the advancement of said loading head wherein a brush is supported at a predetermined position in the work station,

means operable to reverse said drive means wherein a brush in said work station is returned to the loading station.

8. The apparatus of claim 7 having a brush rotating means positioned in said work station and being arranged to rotate a brush supported therein at a predetermined speed.

9. The apparatus of claim 8 having braking means positioned in the loading station for retarding the rotational movement of a brush returned thereto.

References Cited UNITED STATES PATENTS 173,441 2/1876 Boynton 142-3 580,531 4/1897 Reed 29-37 X 649,655 5/1900 Brenner 142-4 1,144,744 6/ 1915 Wheeler 29-27 2,773,333 12/1956 Johansson 51-53 3,267,550 8/1966 Whitturn 29-27 3,432,973 3/ 1969 Heinrich. 1,389,302 8/1921 Hagstrom 300-17 1,796,824 3/1931 Brown 300-17 2,439,771 4/1948 Dahlstrom. 3,092,159 6/1963 Ebser 300-2 X 3,095,240 6/1963 Marks 300-17 3,295,893 1/1967 Adams 300-21 FOREIGN PATENTS 11,264 6/1892 Great Britain.

WAYNE A. MORSE, JR., Primary Examiner US. Cl. X.R. 29-27, 37; 51-53, 215; 142-3, 4

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