Photoelectrostatic Duplicator

Abstract

A photoelectrostatic duplicator equipped with a photoconductive belt mounted on a pair of drive rollers so that the belt moves in predetermined path about the rollers. The rollers are mounted in a pivotally mounted frame that is hinged at one end so that it can be swung into a vertical position when mounting or dismounting the belt. A locking device is part of the frame and it includes sliding bearings which are adapted to engage the main frame of the machine to lock the roller frame into its operating position. To unlock the roller frame the bearings are shifted axially clear of the main frame so that the rollers can be tilted on the hinge. One of the drive rollers has flange portions along its outer edges which keep the belt from "walking" off its course.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to photoelectrostatic copying equipment in which the photoconductive medium is in the form of a reusable belt and more particularly, relates to simplified techniques of mounting the belt-type photoconductive medium.

The advent of organic photoconductive materials has simplified the duplicating process such as described in copending U.S. Pat. Ser. No. 675,463, filed on Oct. 16, 1967, in the name of Evan S. Baltazzi, et al., and assigned to the same assignee as the instant application. Such photoconductive systems permit not only the reuse of the photoconductive medium for different originals in succession, but also the duplication of a number of editions of a single original by utilizing the latent image transfer technique. This technique involves utilization of a latent image upon any type of photoconductive medium, including both organic and inorganic types of photoconductors by successively transferring the powder image and redusting the latent image under controlled conditions. A detailed description of duplicating using latent image transfer is fully described in U.S. Ser. No. 632,819, filed Apr. 21, 1967, in the name of Loren E. Shelffo, and assigned to the same assignee as the instant application. The photoconductive medium in copiers of this general construction have a given useful life span after which time they must be replaced by a new belt. Removal and replacement of the old belt with a new photoconductive medium should be simple to accomplish so that it can be carried out routinely by the operator.

One of the problems with belt drive systems is the tendency for the belt to shift from its course causing binding and possible damage to the belt.

It is a general object of this invention to provide a new and improved photoelectrostatic automatic copying machine for producing high quality reproductions on plain paper.

It is a specific object of this invention to provide an improved photoelectrostatic copying machine having novel means for mounting the photoconductive belt thereon.

It is a further object of this invention to provide a belt-mounting construction that renders the belt easily accessible for removal and mounting without the necessity for complicated readjustment in order to restore the unit to operating condition.

It is a specific object of this invention to provide a simple, effective control for maintaining the belt on a rectilinear course in alignment with the rollers.

The apparatus of this invention comprises in combination, a feed station for receiving an original to be reproduced, an exposure station, a photoconductive medium in the form of a continuous belt disposed about a pair of rollers so that the photoconductive medium moves in a predetermined path, a developing station for applying developer powder to a latent electrostatic image produced on the photoconductive layer which is transferable, a supply of plain paper for receiving the transferable image, a transfer station, and a charging station for applying a sensitizing charge to said photoconductive layer in advance of its movement to the exposure station. The pair of rollers which drive the photoconductive medium in the predetermined path are mounted on a pivotable assembly which can be moved to a raised position for the easy removal of the photoconductive medium and the technique for the replacement of a new photoconductive medium is of equal simplicity.

By a suitable locking mechanism the assembly is restored quickly and effectively to an operating condition which assures proper alignment of the belt movement in its predetermined path past the various instrumentalities recited hereinabove.

The photoconductive medium on which is to be created a powdered or material image is formed into a continuous belt and placed around a pair of axially parallel rollers for moving the photoconductive medium past the several stations. The belt assembly is disposed generally in the central portion of the apparatus and arranged so that the photoconductive surface moves past a number of processing stations which are arranged in a planetary manner about its path of movement. The exposure station is situated at that portion of the belt that spans the two rollers forming an exposure area therebetween.

Superimposed on the belt is a transparent rotatable cylinder extending transverse the width of the belt, tensioning the belt, so that it follows a portion of the surface of the cylinder causing the cylinder to rotate with the movement of the belt. Inside the transparent cylinder is mounted an elongated radiation source for directing electromagnetic radiation onto the photoconductive layer. As the original emerges from the nipping rollers of the feed station, it is received between spaced-apart guide members which guide the original into the nip formed between the transparent cylinder and the photoconductive layer. It will readily be appreciated that the type of exposure arrangement is such that the photoconductive belt forms part of the assembly which supports and conveys a graphic original and at the same time receives a pattern of light and shadow resulting from directing electromagnetic radiation against the original.

In advance of the exposure station there is provided a charging station at which there is applied to the photoconductive layer a sensitizing electrostatic charge in the range of 400 to 1000 volts. A corona electrode is placed just beneath the guide members which comprises a charging station. The electrode comprises a conductive shield maintained at a reference potential, usually at ground, having suspended therein, one or more fine wires connected to a high-voltage DC supply source.

As the original is received between the transparent cylinder and the charged photoconductive belt, it forms an assemblage comprising the cylinder wall, the original, and the belt in which succeeding transverse segments of the assemblage pass the illuminating source, each element of the assembly being in intimate contact with one another. As the radiant energy is activated, radiation is directed onto the original, either against the face or the back of the original, and thence to the charged photoconductive layer producing a pattern of light and shadow thereon. This will result in the dissipation of charges in the light-struck areas so as to result in a latent image on said surface. As each transverse segment of the original is exposed, it advances from between the cylinder and the belt to be received in a receiving tray in the rear of the apparatus.

The belt assembly is constructed in a manner that permits easy mounting and removal of the photoconductive medium. The pair of drive rolls are disposed on a pivotable-mounted yoke assembly that permits tilting the assembly from a locked horizontal operating position to a raised vertical position permitting greatly simplified handling of the belt by merely sliding it over the free end of the roller assembly.

One of the drive rollers is provided with raised flange portions at its outside edges which serves to restrain the edge of the belt from moving over the edge of the roll. The raised portions create a spoollike construction of one of the rolls which is effective to keep the belt on its course and compensates for slight variations in the belt construction that would ordinarily cause it to "walk" off its course.

The rollers are rotatably retained between the parallel sideplates with their shafts being received on bearing members mounted in said sideplates. One of the sideplates is hingedly mounted to the main frame of the apparatus while the other sideplate is equipped with a locking structure for securing the assembly to its operating position on the main frame. The locking structure is associated with the free end of the roller assembly.

The locking structure includes a movable plate associated with the fixed roller-mounting plate. The movable plate is spring biased away from the fixed plate and carries the sleeve bearings which move with the plate being slidably mounted on the roller shafts. The movable plate is biased towards the side frame of the machine urging the sleeve bearings into suitable openings adapted to receive the bearings in the frame assuring that the belt assembly is returned to a predetermined location in the machine. Movement of the bearing plate is controlled by a cam lever which compresses the springs causing the retraction of the bearings from the openings in the main frame so that the assembly can be pivoted to its vertical position along the hinged-plate mounting. In the vertical position the old belt may be removed from the pair of rolls and the new belt easily slipped onto the yoke assembly and then returned to its operating position and locked in place by releasing the cam lever which urges the bearings into the U-shaped cutout.

As part of the roller assembly, one of the shafts has axially mounted thereon inside the fixed plate a drive gear which, in the operating position, meshes with the gear train of the main drive thereby coupling the rollers to the drive system.

Adjacent the path of the belt as it leaves the exposure station is the developing station for applying the electroscopic powder to the latent electrostatic image that is produced at the exposure station. In the instant invention it is found convenient to employ a magnetic brush-type applicator. However, it should be understood that other means of developing a material image may be employed such as cascade development, powder-cloud development or liquid-developing systems. A detailed description of the magnetic brush construction as employed herein may be had by referring to the U.S. Pat. No. 3,246,629, granted Apr. 19, 1966, to Loren E. Shelffo and assigned to the same assignee as the instant invention.

The belt now emerges from the developing station bearing a transferable powder image which may be transferred to a sheet of plain paper. A magazine in which a supply of plain paper is maintained during the operation of the apparatus consists of a horizontal platform or table provided with brackets or sideplates that keep the edges of the stack of sheets in vertical alignment and which is, in effect, an open top tray equipped with a mechanism to advance a single sheet from the top of the stack to a transfer station. The tray is slidably mounted on the base portion of the apparatus and supported in position by side brackets which are received upon a horizontal crossbar suspended above the tray and which also serves as a tie rod for the main frame structure.

A pair of rotatable friction tires rests on the topmost sheet of the stack which serve to advance the sheet to the transfer station in response to an appropriate signal from the electrical control system. The sheet is advanced from the stack in timed relation with the image-bearing portion of the belt so that both will arrive at the transfer station permitting the transfer of the full image carried on the belt in proper registration with the area of the copy sheet and properly located thereon.

The transfer station comprises a transfer roller consisting of a rubber outer layer formed around a hard conductive core which is rotatably mounted between the main frames of the machine so that the axis or rotation of the transfer roller is parallel to the axis of rotation of the second drive roller for the belt drive assembly.

It will be appreciated that the transfer roller is arranged so that it rides against one of the drive rollers of the belt assembly causing the belt to pass between the transfer roller and the belt drive roller. In order to effect the proper transfer of the material image uniformly and completely to the plain paper, it is necessary to strictly control the pressure setting between the transfer member and the photoconductive image-bearing layer. A more detailed description of the importance of pressure in latent image duplication may be found in the aforementioned application, U.S. Ser. No. 632,819, filed in the name of Loren E. Shelffo. In order to assist the transfer of the material image, there is applied a DC voltage to the conductive core which is poled the same sign as the charge in the image bearing portions of the latent image. The potential applied to the transfer station may range anywhere from 300 to 3000 volts depending on the nature of the photoconductive layer.

As the sheet of paper is advanced to the transfer station so that it is sandwiched between the transfer roller and the image-bearing surface of the belt, a positive-reading image is transferred to the receiving sheet. It will be remembered that the image produced on the photoconductive layer at the exposure station is reverse reading.

As the plain paper emerges from the transfer station, it is received into a pair of spaced-apart guide plates and is advanced to a fixing station where the transferred powder image is permanently fixed to the paper support and thence is ejected to a receiving tray for the finished copy.

The fixing of the powder material image may be accomplished using various techniques such as heat fusion of the thermoplastic powder image. It is well known also to use vapor-fusing techniques to soften the synthetic resin particles. Another technique involves the use of pressure systems by which the thermoplastic material is caused to adhere to the plain paper by passing the sheet through rollers in pressure contact with one another. The latter type of fixing arrangement relies on pressure alone.

An important feature of the machine is the control system wherein the aforedescribed processing steps are synchronized with the movement of the belt so as to maintain the proper sequencing control to create the image on the photoconductive medium and then to cycle the belt containing the latent electrostatic image, redusting the image and transferring the powder image to plain paper automatically. The photoconductive material formed into a continuous belt, not only functions as the photoconductive surface on which the latent and powder images are produced, but also its movement in a predetermined path provides a reference against which the sequence of the various processing steps may be timed in order to provide an integrated program. A more detailed description of this feature of the invention appears in the copending application filed of even date herewith in the name of Loren E. Shelffo, Henry A. Mathisen, and Frank L. Schwager, entitled "Photoelectrostatic Duplicator" and assigned to the same assignee as the instant invention.

The belt is provided with a marker or multiple markers which are designed to cooperate with sensing devices for sensing the location of the marker and thereby monitor the position of certain portions of the belt as it moves in its predetermined path. The sensing devices respond to the presence or absence of the marker to initiate or terminate a certain function. A control circuit is coupled with the sensing devices for controlling certain of the instrumentalities necessary to program the entire duplicating process.

DESCRIPTION OF THE DRAWINGS

The apparatus in accordance with this invention for the photoelectrostatic reproduction of images has been generally described and some of its advantageous features pointed out above. The embodiments of this invention will now be described with reference to the accompanying drawings.

IN THE DRAWINGS

FIG. 1 is a perspective view representing the apparatus of this invention which features a contact type exposure;

FIG. 2 is a perspective view looking toward the back of the apparatus with the outside shell removed, showing the belt-mounting mechanism and the exposure assembly in their respectively raised positions;

FIG. 3 is an enlarged detail taken in section along the lines 3--3 of FIG. 8 showing a latching mechanism for the belt-mounting unit;

FIG. 4 is an end view of the latching mechanism of FIG. 3 taken along lines 4--4;

FIG. 5 is a fragmentary perspective view of the retractable bearing mount employed to engage the belt-drive rollers with the drive mechanism shown engaging the side shown in engagement with the side frame of the apparatus;

FIG. 6 is a fragmentary perspective view similar to FIG. 5 showing the bearings disengaged from the side frame;

FIG. 7 is a top view taken along 7--7 of FIG. 5;

FIG. 8 is a perspective view looking toward one side of the apparatus showing the exposure assembly in its open position.

Referring now more specifically to FIG. 1 there is illustrated a copying machine which is indicated generally as 10 and includes a housing 12, and a front panel which carries a main switch 14 for turning on the power. Included on the front panel of the machine is a control dial 16 which is set by the operator for programming the number of copies to be reproduced. At the front of the housing there is provided an infeed station 18 into which is fed the original subject to be reproduced. The machine is adapted to handle varying widths of originals and an adjustable guide element 22 which is slidably mounted on a tie bar 24 may be adjusted to accommodate various widths of originals so that they will be centered on the photoconductive belt. Immediately below the infeed station 18 is an exitway 26 in the front face of the housing through which the finished copy exits from the apparatus.

At the top of the housing a manual lever control 28 is provided for controlling the amount of illumination to be directed onto and through the original to create a pattern of light and shadow on the photoconductive layer.

In FIG. 2 there is shown the apparatus with the outer shell removed exposing to view the mounting assembly for the photoconductive medium in a raised position, the paper feed supply, the radiation source, and the exitway for the original. The various instrumentalities and assemblies are supported between the main right and left sideplates 30 and 32, respectively. The sideplates 30 and 32 are secured to a baseplate 34 which forms the floor of the apparatus and are held in spaced relationship by a pair of tie bars 36 and 37. Between the sideplates there is a magazine assembly 38 in which a supply of plain paper 40 is supported on a horizontal platform or table 42. The table equipped with a set of rails 45 is slidably received on a center track 44 that runs longitudinally along the baseplate 34 which in turn is supported on a bracket 46 that hooks on a tie bar 48 for structurally supporting the sideplates 30 and 32.

Resting on top of the stacked supply of paper 40 is a set of friction wheels 50 which are intermittently operated to advance the uppermost sheet in the stack to the transfer station where all of the powder image created on the belt is transferred to the paper. Thereafter, it is permanently fixed on the paper at the fixing station.

Immediately above the magazine is a guide chute 52 that guides the original that was entered at station 18 out the back of the apparatus after it passes through the exposure station.

The belt-mounting assembly identified generally as 56 is shown in its raised position from its normal position located centrally in the apparatus lying transverse to the direction of the original. In the normal position, the assembly 56 is locked between the side frames 30 and 32. The continuous belt 58 is disposed around a pair of rollers 60 and 62 which are rotatably mounted in an I-shaped yoke 64. The I-shaped yoke 64 is made up of a pair of opposing parallel sideplates 66 and 68 which are held in spaced apart relation by a structural bar member 70 that extends normal to the plate surfaces. The rollers 60 and 62 are rotatably mounted on a pair of parallel-aligned shaft members 72 and 74, said shafts being received in bearing members which, in turn, are mounted in the plates 66 and 68 so that the rolls are free to rotate. The largest cross-sectional dimension of the assembly 56 is smaller than the corresponding dimension of the belt so that it can easily slip on and off the pair of rollers.

The roller 60 is provided with a raised flange portion 75 along the circumference of its outer edges as shown in FIG. 7. The flange portion 75 provides a retention guide for the belt, keeping it on a rectilinear course. The outside diameter of the flange is one-sixteenth to three-eighths of an inch greater than the basic diameter of roll 60. The raised edge 75 restrains the belt from lateral movement with respect to its general direction of movement and therefore provides a uniquely simple control that is extremely effective.

The pivotal mounting of the belt assembly is shown in FIGS. 3 and 4 in which the plate 66 is secured to a hinge element 76 which is adapted to rotate inside a pair of fixed upright plate supports 78 and 80 which extend normal to the sideplate 32. The hinged member 76 turns on the rod portions 81 and 82 (FIG. 3) which extend from the pair of plates 84 and 83, respectively, which in turn are held spaced apart by the member 85. Rod portions 81 and 82 are rotatably received in the upright plates 78 and 80. To latch the belt assembly in the vertical position, a latching mechanism is provided which comprises a tubular member 88, fixed between the flange plates 83 and 84, and having slidably mounted therein a pair of pins 90 which are urged laterally outward from the ends of the tube by a coiled spring 95 disposed inside the tube. The pins 90 pass through openings 94 and 96 in the plates 83 and 84, respectively, to become lodged in the openings 102 and 104 in the left and right sideplates 78 and 80, respectively. Each of the pins 90 has extending normal therefrom through elongated openings 98 in the tube 88 pinch rods 100 which permit retraction of the pins to a position so that their respective free end clears the outermost surface of the flange plates 83 and 84. Openings 106 and 108 are provided in the plates 78 and 80, respectively, so that when the belt assembly is pivoted to its raised position, the pins will normally be urged outward from the tube along its axis into the openings 106 and 108 locking the assembly in the vertical position.

In order to unlatch the assembly to change its position, the pinch rods 100 are moved toward one another retracting the pins 90 until they are completely clear of the openings 102, 104 or 106, 108, depending on the position of the assembly, placing the spring 95 under compression and thereby permitting the belt assembly to be pivoted to its changed position which is determined when the pins 90 are in alignment with openings 102, 104 or 106, -08 at which time the spring 95 urges the pins outwardly into the openings, thereby latching the assembly in either the horizontal or the vertical position.

Referring now to FIGS. 5, 6, and 7 there are shown the details of the latching mechanism that aligns the rollers 60 and 62 so that they are properly engaged with the drive mechanism in a manner that permits the belt to coact with the other portions of the drive system in order that it be properly moved along its predetermined path. The drive rollers in the belt assembly must be in proper alignment with the other drive systems in the apparatus controlling the original path and the copy sheet path so that these elements properly engage the belt as all of the elements move in their respective paths.

A drive gear 110 (FIGS. 6 and 7) is mounted on the portion of the shaft 74 of the roller 60 that is just inside the plate 68. The gear 110 is part of a gear train consisting of gears 112 and 114 (FIG. 7) which are coaxially mounted on the main-drive shaft 116 coupled to the main-drive motor (not shown). Part of the gear train includes 118 and 120 axially mounted on stub shafts 122 and 124, respectively, being rotatably mounted in a support bracket 121. The gears 118 and 120 are continuously driven through engagement with gear 114 which in turn is directly coupled through shaft 116 to the main-drive motor. Gears 118 and 120 are coupled to the friction wheels 50 (FIG. 2) through clutch units 126 and 128 and the gear-belt drive (not shown) which controls the directional rotation of the feeder wheels.

It will be appreciated that the belt assembly 56 when it is lowered to its normal position must be in registration with the other drive elements of the apparatus so as to be able to receive, for example, the copy sheet which is now advanced to a ready position. Associated with the plate 68 is a second movable plate 138 (FIG. 7) in parallel alignment with the plate 68 having openings therein to receive the extensions of shafts 72 and 74. A pair of pins 140 having one end affixed to the plate 68 extend through the plate 138. The free ends 140a of the pins 140 which extend through the plate 138 carries the cam lever 144 which is received between the pins extending from the outward face of plate 138. The cam lever 144 is pivotably received on a crosspin 146 secured between the pins 140.

Surrounding the portions of the pins 140, contained between the plates 68, 138 are a pair of coiled springs 148 (FIG. 7) anchored to the opposing faces of the respective plates, and which urge the plate 138 outward from the plate 68 in a sliding manner over the shafts 72 and 74 and the pins 140. The plate 138 is equipped with bearing members 150 and 152 which are fittingly received in the respective cutouts or openings 156 and 158 in sideplate 30 and on the shaft 72 and 74. The bearing members 150 and 152 are of a width that is greater than the thickness of the sideplate 30 being only partially received inside the sideplate 30 leaving exposed the bearing surfaces 150A and 152A.

Cutout portions 156 and 158 are provided in the main sideplate 30 to receive the exposed portions of the bearing members 150A and 152A, respectively.

By rotating the cam 144, the cam face 144A engages the plate 138 which is urged against the plate 68 placing the coiled springs 148 under compression thereby dislocating the exposed bearing portions 150A and 152A out of alignment with the openings 156 and 158 (FIG. 6).

With the bearing portions in their retracted position, the belt assembly may now be moved from its horizontal position to its raised position. In the circumstance that it is desired to return the assembly 56 to its normal position the pinch rods 100 are moved towards one another retracting the pins 90 from the openings 106 and 108 and lowering the assembly to its horizontal position. As the pins 90 line up with the openings 102 and 104 they are urged outward from the tube 88 and received into said openings. By releasing the cam lever 144 the springs 148 under compression urge the plate 138 and the bearings 150 and 152 outward from the plate 68 sliding along the shaft 72 and 74 and thereby urge the pins 140 into engagement with the cutout portions 156, 158 (FIG. 5) placing the entire belt assembly in its proper alignment with the rest of the apparatus.

Referring again to FIGS. 2 and 8 there is shown the drive rollers 160 and 162 at the infeed station that control the movement of the original into the exposure station. The upper roller 162 is an idler roller that rests on top of roller 160 which can be driven from a separate motor (not shown) and also by the main drive motor (not shown) through the belt drive 170 on the left side of the apparatus (FIG. 8) which is transmitted through a main drive shaft 171. The roller 160 is coupled to the shaft 171 through the belt drive 170. An electric clutch unit 172 couples the roller 160 with the drive. The separate drive motor that drives roller 160 is energized when the main drive switch 14 is actuated thereby driving the rollers 160 and 162.

As the original is guided by the element 22 into the apparatus the lead edge thereof engages the actuator 173 of switch 174, closing switch 174 which deenergizes the separate drive for roller 160 and actuates the clutch 172 so that the original feed rollers are again rendered operative after a brief interruption to allow for the belt-monitoring system to take over the movement of the original in synchronization with the location of the belt relative to its home position. The use of the separate drive for the infeed of the original permits another element of control during the duplicating mode, at which time the infeed is disabled so that the equipment is not able to receive an original during the duplicating mode.

The exposure assembly including a transparent cylinder 178 is mounted on a pair of swingably movable arms 180 and 182 which pivot about the rod 184 which in turn is rotatably mounted between the side frames 30 and 32. The cylinder 178 surrounds an aluminum tube 186 which is provided with a longitudinally extending aperture 188 equipped with an adjustable shield 189 controlled by the lever 28. The cylinder 178 is concentrically supported in position around the tube by the end rings 190 each being equipped with a series of guide pins 192 that extend normal to the rings and inboard thereof in direction of the cylinder so as to engage the inside surface of the cylinder 178 forming a loose-fitting bearing support. The rings 190 axially fit onto the tube 186 and are separated by a distance slightly longer than the length of the cylinder 178 with the pins 192 being received within. The pins 192 are preferably made of a material such as nylon or Teflon so as to reduce the frictional forces.

Inside the aluminum tube 186, preferably along the centerline thereof, is a conventional tubular lamp (not shown) which is capable of emitting the electromagnetic radiation necessary to expose the charged photoconductive medium.

The exposure assembly may be swung into a raised position as shown in FIG. 8 so as to permit easy access to the inside of the machine when lowered into its operating position the transparent cylinder is received in the space between the rollers 60 and 62 so as to place the loosely fitting belt 58 under tension causing the belt to course over the outside surface of the rollers 60 and 62 and underneath the transparent cylinder 178 forming therebetween the exposure zone of the various surfaces which are in intimate contact with one another. The condition of placing the belt under tension is maintained by a tensioning spring 194, one end of which is secured to the arm 180 and the other anchored to the frame 32.

As the original passes between the nipping transparent cylinder 178 and the belt 58, it is exposed to the electromagnetic radiation emitted through the elongated slot 188 as it is advanced by the moving belt and is carried upward to discharge the original into the chute 52 at the rear of the apparatus. The original is prevented from deviating from the discharge path by the guide member 199 that is carried on the sidearms 180 and 182. The guide member 199 is arcuately shaped and is in superposed relation above the roller 162 so as to form a guideway 200 (FIG. 2) between itself and the moving belt.

While the apparatus of the instant invention has been set forth in substantial detail it is intended to cover these modifications of the described structure that would occur to those of ordinary skill in art that comes within the scope of the appended claims.

Claims

What is claimed is:

1. In a photoelectrostatic copying apparatus for making reproductions from a continuous photoconductive belt adapted to move in a predetermined closed path within said apparatus, means for removably mounting said belt comprising:

a main frame,

a support frame including a pair of spaced end members;

a set of axially parallel rollers supporting the belt and rotatably mounted in said support frame between said end members;

pivotal support means coupled between said main frame and one of said end members of said support frame to render the roller set movable from an operating position in said path to a loading position in which the free end of said support frame and roller set is exposed to receive the continuous belt,

drive means for rotating said roller set, and

support means on said main frame releasably engageable with the other of said end members for lockingly engaging the free end of said roller set in the operating position whereby said belt moves in said predetermined path,

said roller set, support frame, and end members being dimensioned so that the belt is slidably removable over said other end member.

2. In a photoelectrostatic copying apparatus for making reproductions from a photoconductive belt adapted to move in a predetermined path within said apparatus, means for removably mounting said belt comprising:

a set of axially parallel rollers rotatably mounted in a support frame,

pivotal support means for receiving one end of said frame to render the roller set movable from an operating position in said path to a loading position in which the free end of said frame and roller set is exposed to receive the continuous belt,

drive means for rotating said roller set, and

support means for lockingly engaging the free end of said roller set in the operating position whereby said belt moves in said predetermined path,

said pivotal support means comprising a pair of apertured, spaced-apart support members and a hinge member attached to said one end of said frame, said hinge member including a pair of rod portions extending outwardly from opposite ends of said hinge member and each being received in one of the apertures in a respective one of said support members for rotational movement therein.

3. A photoelectrostatic copying apparatus as claimed in claim 2, wherein said pivotal support means further includes a latching mechanism for retaining said frame and roller set in said operating and loading positions, respectively, said latching mechanism including at least one movable pin member receivable in predetermindedly placed second and third apertures in a corresponding one of said support members, whereby upon pivoting said roller set to said operating position, said pin member is receivable in said second aperture and upon pivoting said roller set to said loading position, said pin member is receivable in said third aperture.

4. A photoelectrostatic-copying apparatus as claimed in claim 3 wherein said latching mechanism includes a pair of pin members each being receivable in a respective second and third aperture in a respective support member for retaining said frame and roller set in said operating and loading positions, respectively, said latching mechanism further including a hollow tube member receiving said pin members, one in each end thereof and a coiled spring member mounted in said tube between opposing ends of said pin members urging said pin members outwardly from the ends of the tube toward a respective support member, each of said pin members including a pinch rod extending outwardly of the tube through a respective slot formed in the wall of said tube provided therefor, so that upon moving the pinch rods toward each other against the force of the coiled spring member said pin members are urged away from said support members, and upon releasing said pinch rods, said pin members are urged by said coiled spring member toward said support members and into said second or third aperture, as the case may be.

5. In a photoelectrostatic copying apparatus for making reproductions from a photoconductive belt adapted to move in a predetermined path within said apparatus, means for removably mounting said belt comprising:

a set of axially parallel rollers rotatably mounted in a support frame,

pivotal support means for receiving one end of said frame to render the roller set movable from an operating position in said path to a loading position in which the free end of said frame and roller set is exposed to receive the continuous belt,

drive means for rotating said roller set, and

support means for lockingly engaging the free end of said roller set in the operating position whereby said belt moves in said predetermined path,

said support means including a rigid support member mounted on said copying apparatus in alignment with the free end of said frame and a plurality of retractable bearing members, one associated with each of the rollers of said set and each being lockingly engageably with said rigid support member upon moving said roller set to the operating position, whereby said rollers are rotatable on said bearing members to allow said belt to move thereover along said predetermined path.

6. A photoelectrostatic-copying apparatus as claimed in claim 5 wherein the free end of said frame includes a plate having said bearing members mounted thereon, spring means coupled to said plate, urging the plate and bearing member toward the free end of the roller set, and a cam operatively connected to said plate and being movable to a first position against the force of said spring means for moving said bearing members into a retracted position, causing said bearing members and said support member to become disengaged and to a second position allowing said plate and bearing members to be moved to a protracted position, whereby said bearings are lockingly engageable with said support member.

7. A photoelectrostatic copying apparatus as claimed in claim 1 wherein at least one of said rollers of said set is spool-shaped including a flange portion along the circumference of each outer edge thereof so as to provide a retention guide for said photoconductive belt mounted thereon, the width between said raised outer flange portions being substantially equal to the width of said belt.

8. The apparatus of claim 1 further including manually releasable latch means operatively associated with said one end member for releasably holding said support frame and roller set in said loading position.