NO147626B - PROCEDURE FOR THE PREPARATION OF A MEDICAL PREPARATION WITH DELAYED RELEASE OF THE THERAPEUTIC ACTIVE INGREDIENT - Google Patents

Abstract

Process for the preparation of a medicinal preparation with delayed release of the therapeutically active ingredient.

Description

Xerographic copying machine.

This invention relates to a xerographic copying apparatus

for producing several copies one after the other, equipped with a drum with a photoconductive surface on which, in order to produce an electrostatic latent image, an optical image of an original to be copied is projected, the surface of this drum passing by a number of processing points during its rotation and where the device contains controllable grippers in connection with a rotatable original carrier.

In the xerography process described, for example, in US Patent No. 2,297,691 or No. 2,357,809, a xerographic plate having a layer of photoconductive insulating material on a conductive substrate is given a uniform electrical charge across its surface, after which the exposed with the material to be copied, usually by normal projection methods. This exposure discharges the different areas of the plate according to the intensity of the light that hits them, thereby producing an electrostatic image on or in the plate coating.

Development of the image is carried out with a developing material or developers which are usually formed from a mixture of a suitable pigmented or colored electroscopic powder, hereafter called "toner", as well as a grain-shaped carrier material, which provides for carrying and generating triboelectric charges in the toner. Explained more precisely, the function of the granular material is to ensure a mechanical control of the powder, or to lead the powder to an image surface and at the same time to ensure as complete a homogeneity of charge polarity as possible. During the development of the image, the toner powder is brought into contact with the plate and held electrostatically on it in a pattern corresponding to the electrostatic latent image. Then the developed xerographic image is usually transferred to a carrier or a transfer material to which it can be fixed in a suitable way.

After the basic idea of the xerography process had been developed. In recent years, a large number of machines and devices have been proposed to utilize this basic idea in such a way that xerographic copies can be produced in a practically feasible manner. For the most part, each of these devices has been specifically intended to solve a particular copying problem, and has for the most part been limited to its particular area of use.

It is therefore the main object of this invention to produce an improved xerographic copying apparatus for general copying purposes of the kind usually used in business life, especially for smaller offices, which will be able to produce copies quickly, automatically, cheaply and accurately.

Another object of the invention is to improve xerography devices so that copies of a moving document or the like can be produced automatically.

According to the invention, this can be achieved by an apparatus of the type mentioned at the outset which comprises a control system with a counter which, after prior setting in accordance with the number of copies to be copied, causes the control system to remain in a first position with active grippers until the production of the last copy and then causes the control system to assume another position with inactive grippers so that the document is released from the original carrier during the production of the first copy.

In order to provide a better understanding of the invention and of other purposes and features thereof, reference will be made to the following detailed description in which reference is made to the accompanying drawings, where: Fig. 1 shows a schematic illustration of the device according to the invention.

Pig. 2 shows a top view of the device according to the invention, with the housing covers removed.

Pig. 3 shows a top view of the apparatus similar to fig. 2, but with the optical projection mechanism removed.

Pig. 4 shows a vertical section through the apparatus.

Pig. 5 shows a section laid along the line V-V in fig. 2.

Pig. 6 shows a section laid along the line VI-VI in fig. 3, and illustrates a document stopper.

Pig. 7 shows a section laid along the line VII-VII in fig. 3, and illustrates a document holder and a pressure finger.

Pig. 8 shows a section laid along the line VIII-VIII in fig. 3, and illustrates a docuraent intestine.

Pig. 9 shows a section laid along the line IX-IX in fig. 3, and illustrates the document locking mechanism.

Pig. 10, 11, 12 and 13 show sections corresponding to figures 6, 7, 8 and 9 respectively, and illustrate the position of the respective elements, when a document is picked up by the gripper bars on the Icopi drum.

Pig. 14 shows a perspective view, seen from the front. left r-m», »y the mechanical control mechanism in the device.

Pig. 15 shows a perspective view of the right side of the programming mechanism in the device.

Pig. 16 shows a perspective view, seen from the right, of the programming mechanism and the document processing mechanism, set up for making single copies.

Pig. 17 shows a perspective view, seen from the right side, of the programming mechanism and the document processing mechanism, set up for making a plurality of copies.

Pig. 18 shows a front view of the timing cut-out cam and the timing cut-out locking mechanism.

Pig. 19 shows a section laid along the line XIX-XIX in fig. 18.

Pig. 20 shows a perspective view, seen from the right side, of the timing cut-out cam mechanism, seen from the back of the machine.

Pig. 21 schematically shows an electronic coupling diagram for the apparatus.

Referring now to the drawings, they show a xerographic copying apparatus which is used for producing xerographic copies from an original that moves. The xerographic copier is intended to be installed together with a suitable light-proof housing of such a size that the entire unit can be placed on an office desk or table.

Generally.

As shown, the xerographic apparatus contains a xerographic plate with a photoconductive layer or an illuminating surface on a conductive substrate, and designed as a drum, generally designated by the reference numeral 20, which is supported in a frame so that it can rotate in the direction indicated with the arrow, so that the surface of the drum will pass by a plurality of xerography processing sites in turn.

For further explanation, the various xerography processing locations in the movement path of the drum surface can be described functionally, as follows: A charging location, where a uniform electrostatic charge is deposited on the photoconductive layer of the xerographic drum.

An exposure point, where an illumination pattern or radiation pattern of a document to be copied is projected onto the surface of the drum so that the drum's charge is discharged in the exposed areas on it, thereby forming a latent electrostatic image of the document to be copied.

A developing site, where a xerographic developing material containing toner particles with an electrostatic charge opposite to that of the electrostatic latent image is sprinkled over the surface of the drum, whereby the toner particles adhere to the electrostatic latent image so as to form a xerographic powder image of the same shape as the document to be copied .

A transfer point, where the xerographic powder image is electrostatically transferred from the surface of the drum to a transfer material or carrier surface.

A drum cleaning station, where the drum surface is first charged and then brushed or wiped to remove any remnants of toner particles that may remain on the surface after the image transfer, and where the drum surface is exposed to relatively strong lighting so that a complete discharge of any remaining is achieved, so to speak electrostatic charge on the surface.

The charging point is preferably located as indicated by the reference designation A in the schematic illustration of the device. Generally speaking, the charging apparatus or corona charging device 2\ contains a corona discharge unit with one or more discharge electrodes which extend across the surface of the drum and which are energized from a high-voltage source and are, so to speak, completely enclosed within a screen.

After this location in the path of movement of the xerographic drum there is an exposure location B. This exposure location may be designed as any one of a number of types of mechanisms or parts, preferably an optical scanning system or projection system or the like, which is intended to project a line copy image onto the surface of the photoconductive xerographic drum from a suitable original.

The optical scanning assembly or projection assembly is formed by a copying tray in the form of a drum, hereinafter referred to as the copying drum 30, which is intended to carry a document to be copied and which is arranged to rotate light-projectingly in relation to it traveling light-receiving surface on the xerographic plate. Even lighting is obtained from suitable lamps 31 attached to a slotted light reflector 32 mounted near the copy drum.

A slitted light screen 33, adapted to protect the xerographic plate from side light, is placed near the surface of the xerographic plate. A slit opening in the light screen extends across the path of movement of the light receiving surface of the xerographic drum 20, so that reflected rays from the copy drum are directed towards a limited transverse area of the light receiving surface, as it passes below.

In order to make it possible to enclose the optical system inside a relatively small housing, a folded optical system with an object mirror 34, a lens 35 and an image mirror 36 is used in the preferred embodiment of the apparatus.

A document which is fed through the document guide 37 to the copy drum is removably held thereon by a suitable gripping mechanism for movement with it in a timed relationship to the movement of the xerographic drum, so that a moving image of the document is projected onto the xerographic drum. The copy is held against the surface of the copy drum, until it is gripped by document holder guides 38. Pressure guides 39 and a document protector 41 retain and guide the end edge of the document on the copy drum. After the copy is scanned, it is released from the copy drum to be transported out of the machine by the copy drum and document delivery rollers 42 through a document removal guide 43.

Near the exposure site there is a development site

C, where the development apparatus 50 which comprises is placed

a developer housing with a bottom part or sump part for collecting developer material 51. Inside the developer housing, a driven conveyor 52 of the trough type is mounted, which is used to lead the developer material that was previously supplied to the developer housing to the upper part of the developer housing, from where the developer material is brought to to sprinkle over a feed chute 53 and down onto the drum.

As the developer sprinkles over the drum, toner particles will. of the developing material adhere electrostatically to the previously produced electrostatic latent image areas on the drum, so that a visible xerographic powder image is formed; the remaining developing material falls off the circumferential surface of the drum and into the bottom of the five-chamber housing. Toner particles which are consumed during the developing step to form the xerographic powder images are replaced by a toner dispensing apparatus 54, of the type described in British Patent No. 935,501, which apparatus is mounted inside the developer housing.

Close to the development site, an image transfer device I) is placed which comprises a suitable sheet feeding mechanism which is arranged to feed paper sheets in sequence to the xerographic drum, coordinated more} that a developed image is formed on the drum during the transfer stage. The sheet feeding mechanism comprises a sheet supply, such as a paper conveyor 60 for a plurality of sheets of a suitable carrier material, which will nine paper sheets or the like, separator rollers 61 arranged to A feed the ton cardboard from the stack of carrier material through a guide 67 to a sheet transport mechanism 62 with paper grippers 63 which brings the sheet-like carrier material into contact with the rotating xerographic drum, coordinated with the fact that it presents a developed image above the device.

The transfer of the xerographic powder image from the drum surface to the carrier material is carried out by means of a corona transfer device 64 which is placed at or just after the point of contact between the carrier material and the rotating xerographic drum. The corona transfer device 64 is largely similar to the corona discharge device used at the charging point, in that it also includes a series of one or more corona discharge electrodes which are energized from a suitable high voltage source and which extend across the troinmel surface and are largely completely enclosed within a core. During operation, the electrostatic field which produces.1; of the corona transfer device ensure that the transfer material will adhere electrostatically to the drum surface, and at the same time as this adhesion effect, the electrostatic field will serve to attract the toner particles that form it. xerographic powder images from the drum surface and cause them to adhere electrostatically to the surface of the carrier material.

As the paper gripper continues to move forward in its closed circuit, it will pull the support material off the xerographic drum and pass it to a fixing device, such as a heat fuser 70, where the developed and transferred xerographic powder image on the support material is caused to adhere perma- nent to this.

After melting, the finished copy is preferably quickly removed from the apparatus at a suitable place for collection on the outside of the apparatus. In order to achieve this, a pair of delivery rollers 65 and 66 are provided, whereby the copy is delivered from the machine after it has been released from the gripping mechanism. At the transport mechanism's receiving point and outlet point, suitable cam members 68 and 69 are placed respectively, to influence the paper grippers at these points so that they take up or release the sheet of carrier material.

The next and last place in the apparatus is a drum cleaner E, where any powder that may remain on the xerographic drum after the transfer step is removed, and where the xerographic drum is illuminated so that any remaining electrical charge left on the xerographic drum is discharged.

In order to help remove any powder that may be left on the xerographic drum, a pre-cleaning corona device 84 is arranged, which is largely similar to the corona discharge device used at charging point A. Removal of residual powder from the xerographic drum is achieved by by means of a web cleaning device 80 arranged to continuously feed a clean, fiber-shaped web material to a wiping facility against the xerographic drum. As shown, the web material 55 is taken from a supply roll 81 and passed around a cleaning roll or pressure roll 82, which is preferably made of rubber, over to a take-up roll 83.

Any electrical charge that may remain on the xerographic drum is discharged by light from a fluorescent lamp 85 which is mounted in a suitable bracket above the xerographic drum, a suitable starter with associated ballast being provided to energize the fluorescent lamp.

Suitable drive means drive the xerographic drum, the copy drum, the sheet conveyor mechanism at specific speeds in relation to each other, and provide for the operation of the paper separation roller and the web cleaning mechanism, the latter being driven at a speed such that a relative movement is achieved between the xerographic drum and the web material. Suitable drive means are also arranged which ensure operation of the transport mechanism and the toner dispensing device in the development apparatus.

Referring now to the drawings, one is arranged

frame sorr bars the components of the apparatus, and this is formed by a left side plate 10, an intermediate plate 11 and a right side plate 12, which are connected to each other and held in place at a distance from each other by suitable cross bars 13 and 14 (fig.2).

The xerographic drum 20, which carries a layer of photoconductive insulating material on a conductive substrate, is mounted on

a horizontal, driven shaft SH1 3which rotates in bearings 22 and 23 mounted in the plates 11 and 12 respectively. The free or left end of the shaft SH1, calculated according to figure 3, is threaded so that they occupy a K.utter 24. A spring 25 , which surrounds the free end of the shaft, presses the drum to the left into drive engagement with a pin 26 which extends from the hub portion of a sprocket wheel 27 which is attached to the shaft SH1. The left end of the drum is equipped with a suitable opening so that it can accommodate the pin 26.

The exposure mechanism.

The exposure mechanism in the xerographic copying apparatus is intended to use an optical projection mechanism or sensing mechanism adapted to sense a document or copy placed around a rotating copying drum and to project a moving image of the document or copy onto the photoconductive surface of the rotating xerographic drum.

As shown, the sensing mechanism contains a supply point,

a copying place, an exposure place, as well as means for guiding the document through the copying place synchronously with the movement of the xerographic drum.

The supply point contains a document guide 37 which extends between frame plates 10 and 11, through which the document or copy to be copied is guided forward to abut against the copy drum 30 and document stoppers on the document holder guide 38 (fig.1), the latter orienting and holding the document in place so that it can be grabbed by the gripper fingers on the copy drum.

The document holder guide 38 contains a shaft 101 which is stored in bearings 102 and 103 (fig. 3) which are placed in the frame plates 10 and 11 respectively. Axial stability of the shaft is maintained by means of retaining rings 104 which are placed in suitable grooves in the shaft near opposite sides of the bearing 103 (fig. 6).

A distance plate 105 is attached to the shaft 101. At a distance from each other on the distance plate, a number of pressure fingers 106 are mounted which are arranged to be brought into contact with the peripheral surface of the copy drum or a document lying in between, so that a the edge of a document is pressed against the copier. A range of document stoppers 107 and document thqlders. 108 is mounted loosely on . the shaft 101 flush with the cut-out portion of the spacer plate. As shown in Fig.6, the document stoppers 107 are normally pressed into engagement with the peripheral surface of the copy drum by means of leaf springs 111 which are attached to the spacer plate...■,

A document inserted by an operator in the document management

37, is pressed into contact with the paper drum by the document holders 108,

and its forward movement is stopped by the document stoppers, which also serve to fold the leading edge of the document parallel to the axis of the copy drum. Each of the document holders is supported freely on the shaft 1.01 in an eccentric position, so

that the document holder will normally be turned by its own weight into contact with the copy drum or into contact with a document lying on it, with sufficient force to hold the document against the peripheral surface of the copy drum. The weight of the document holders is such that the applied force acts against the document holders. the copy drum is of such a limited size that even if the document holders want to hold a document against the copy drum, will. these document holders.move when they come into contact with the leading edge.of a document, so that the document can be inserted between the document holders and the copy drum.

To the right end of the spacer plate, set in four. 3, an actuation arm 114 is attached which extends beyond the end of the copy drum, and on the right end of the shaft 101 a locking stopper 115 is mounted, for reasons which will be described in detail in the following.

The shaft 101 is normally pressed in a clockwise direction, as seen in fig. 6, by a spring, 112 (Fig. 3) so that the document stoppers and pressure fingers are pressed into abutment against the peripheral surface of the copy drum; Spring 112

is connected at one end to a peg 113 which is fixed in the frame plate 10, and at its other end to the spacer plate 105, there being: a suitable opening in this for fixing the bent end of the spring.

The copy drum 30 is attached to an acael SH2 which is rotatably supported in bearings 121 and 122 which are placed in the frame plates 10 and 11 respectively.

The shaft SH2 is kept aligned axially by means of retainer rings 123 which are placed in suitable grooves formed in the shaft SH2

near the bearings 121 and 122 (fig. 4).

The hub 124, which is attached to the shaft SH2, is provided with an axial hub pin 125 which is adapted to extend within a suitable opening in the right end plate of the copier, whereby the copier is secured to rotate with the shaft. The copy drum is normally pressed into drive engagement with the hub pin by a spring 126 which surrounds the left end of the shaft SH2, seen in fig. 4.

The copier drum is driven at an adjusted time setting in relation to the xerographic drum by a chain 131 which runs on sprockets 132 and 133 (fig. 3) which are attached to the shafts SH1 and SH2 respectively. As shown in fig. 5, the chain 131 runs from the sprocket 132, under a sprocket 134 which is supported on the shaft SH13" around the sprocket 133, over an idle sprocket 135 supported on a shaft pin SH18, and then back around the sprocket 132.

The peripheral surface of the copy drum is equipped with slots 141 which run parallel and in line with each other, through which gripper fingers 142 run which grip the leading edge of a document and press it against the peripheral surface of the copy drum. The gripper fingers are attached to a rocker shaft 142 which is rotatably supported in bearings 138 which are placed in the end plate of the copier drum, in such a way that when the rocker shaft is rotated, the gripper fingers will be jointly moved to and from a working position in which they press against the peripheral surface of the copier drum. Axial setting of the rocker shaft is secured with retainer rings 139 placed in suitable grooves formed in the rocker shaft.

(Jriperf ingers are normally pressed into working engagement;not the circumferential surface of the copy drum by means of a spring 144 which is attached at one end to a pin 145, extending from the left "third end plate of the copy drum, seen in Fig. 4" and which at its other end is connected by a pin 146 which extends from an arm 147 which is attached to the left end of the rocker shaft 143. A cam arm 148 is attached to the right end of the rocker shaft, seen in Fig. 4, in such a position that it is grasped by an intermediate pin 151 for opening the gripper mechanism to receive a document or to release a document.

The intermediate pin for opening the gripper mechanism is arranged to be moved manually either to a position for work engagement with the chamber arm 146 on the rocker shaft, when the copy drum rotates, or possibly to an inactive position to clear the chamber arm for a purpose that will be described in more detail in the following . When intermediate tapeu. 151 is in an active position, ao. u shown in fig. 3, the rocker shaft is automatically affected with each revolution of the copy drum, so that a document held by the gripper fingers is released to be emitted from the apparatus, and the gripper fingers are held open long enough to be able to receive a new or different document. The rotary movement of the rocker shaft is limited by means of stop pins 149 which are attached to the left end plate of the copier, so that they are gripped by the arm 147.

In order to enable multiple filing of a document, the intermediate pin 151 is moved to the right, to the position shown in fig. 4, out of position for engagement with the chamber arm 148, by an operator by influencing the control button 6, which will be described in more detail hereinafter.

The intermediate pin 151 (fig. 4) is displaceably mounted in a housing 153 and a housing cover 154 which is attached to the frame plate 11 by means of screws 155 which are screwed into this. The intermediate pin 151 is pressed into engagement with the chamber arm 148 by means of a spring 156 which surrounds the intermediate pin and which at the opposite ends rests against the housing cover 154 and the retaining ring 157 which is placed in a suitable groove formed in the intermediate pin. An impact arm 161, which is supported on a pin 162 which is placed on a bracket 163 attached to the frame plate 11, is used to move the intermediate pin out of engagement position in relation to the chamber arm 148. The fork-shaped end of the impact arm surrounds the intermediate pin behind an intermediate stop 158 which is attached to this at one end, and at its other end the influence arm is arranged so that it is influenced by a cam 602 in the programming mechanism which will be described in detail hereinafter.

In order to enable a document held by the document stoppers to be gripped by the gripping fingers on the copy drum, the influence arm 114 of the document holder suspension 38 is placed on a shaft 101 so that it extends beyond the right edge of the copy drum and can engage with the rocker shaft 143" whereby the shaft 101 is turned so that the document stoppers that bear it are brought out of engagement with the leading edge of the<*> document, at the same time as the leading edge of the document is gripped by the gripper fingers 142 (fig.4).

When the document, as in the case of the" leading edge, is gripped between the gripper fingers and the peripheral surface of the document drum, transport thereby

raw

through the kbpiering site, which is formed by the slitted light reflector

32, successive portions of the document will be illuminated uniformly by lamps 31. As shown in the electrical connection diagram, four lamps are used to illuminate the copy, that is, a pair of fluorescent lamps LMP2 and LMP3, and a pair of incandescent lamps LMP4 and IMP5 .

In order to receive the image of the document reflected through the light reflector, an object mirror 34 is placed which reflects the image through a lens 35. An image mirror 36 is placed in the light path from the lens so that the image is reflected onto the xerographic drum through the slit opening in the light screen 33. The lens 35

and two mirrors are suitably attached to an optical mounting bracket 171 (Fig. 2) which is carried by support rods 14 extending between the plates 10 and 11. The mounting bracket is held in place on the support rods by means of springs 172 which are attached to i. bracket and at the opposite end to the support rods. Suitable light shields, not shown, are attached to the underside of the optical mounting bracket 171 to shield the lens 35 from side light.

The slotted light screen 33 is quite simply an open, elongate box whose bottom has a narrow slotted opening running transversely across its length. The light screen is suitably mounted with a clamp-on attachment 173- to a support rod'14 extending between the plates 10 and 11, directly above and close to the circumferential surface of the xerographic drum, with the center line of the slot opening parallel to the axis of the shaft SH1.

When a document is advanced through the copy location, the end portion of the document is held against the peripheral surface of the copy drum by pressure fingers 106 on the shaft 101, and then, when it leaves the copy location, by pressure guides 39. The pressure fingers 106 and the pressure guides 39 also perform the function of holding curled or curved documents flat in the exposure area. The pressure guides 39 and the curved document protection 41 are attached at opposite ends to brackets 164 which are attached to the plates 10 and 11.

After a document has been sensed, rocker shaft 143 is actuated so that the document is released, whereby it is carried forward by output rollers 42 which interact with the circumferential surface of the kdpering drum, through the document removal guides 43 (Fig. 1).

■ The output rollers 42 are stored rotatably on arms 181 which

is supported on a shaft SH20 which is fixed non-rotatably between the plates 10 and 11. Each of the arms 181 is pressed with the help of a torsion spring 182 so that they yieldingly press the discharge roller carried by them against the peripheral surface of the copy drum or a document which is placed-on this. Each torsion spring has one end attached

to a radial pin T3'5 extending from the shaft SH20, and the other end of each spring is attached to the arm 181 (Fig. 4) with which it cooperates.

The machine operation.

The xerographic drum is rotated at constant speed by a gear 91 (Fig. 2) attached to the drum shaft SH1 which carries the xerographic drum, from a main drive motor M0T3. The gear 91 meshes with a spur gear 92 which drives a gear 93 which is attached to the shaft of the main drive motor M0T3. The tray transporter and toner dispensing device in the developing apparatus 50 is suitably driven by a motor M0T2, shown in FIG. 21. Suitable fans, not shown, driven by motors MOTI and M0T4, are used to remove heat generated by the fuser and projection lamps from the machine.

In a normal office, it is usually necessary to produce at arbitrary intervals during the day a single copy of an original, a plurality of copies of an original, or successive copies from successive originals.

To produce a single copy, a document is introduced into the machine through the document guide 37 into contact with the copy drum 30. The document is advanced through the document guide 37, until its forward movement is stopped by the document stoppers 107, and in this position the document is held against the peripheral surface of the copy drum by the document holder 108, after which the operator can drop the document.

When the document is introduced into the document guide, its leading edge will trigger the limit switch 6LS, which is placed under the document guide with its trigger extending through a suitable opening in the document guide, whereby its contact is closed so that a circuit is closed which starts the operation of the machine. This means that at this time the main drive motor M0T3 is supplied with power so that the xerographic drum 20, the copy drum 30 and the sheet transport mechanism 62 are set in rotation, The motor M0T2 is also supplied with power to ensure the operation of the developing mechanism 50 and the toner delivery device 54. The solenoid S0L2 is energized so that the locking plate in the heat melting device 70 is opened.

Power is supplied to the exposure lamps at the exposure location; that is, the fluorescent lamps LMP2 and LMP3 are supplied with current through their circuits consisting of ballasts L1, 12 and 13, 14, as well as starters S1 and S2, respectively. The lamps LMP4 and LMP5, which are connected in series with each other, are supplied with power through the line connected to the secondary winding line in the transformer T2-A, which is also supplied with power at this time. The discharge lamp 85, a fluorescent lamp LMP6 as shown in the circuit diagram, is energized through its circuit consisting of a ballast L5 and a starter switch S3. Power is also supplied to the high voltage power source PS1 to provide for starting the corona charging device 21, the corona transfer device 64, and the corona purification device 84.

When the xerographic drum 20 now rotates under the corona charging device 21, a uniform electrostatic charge is applied to the photoconductive layer of the drum. As the xerographic drum rotates past the exposure location, a light image or radiation image of the document carried by the rotating copy drum 30 is projected, by means of the mirror and lens assembly described above, onto the surface of the drum, so that the charge on the drum is discharged in accordance with the light pattern or the radiation mask from the document, so that a latent electrostatic image of the copy is formed on the xerographic tronuael.

The exposed portion of the drum then rotates to the developing site C, where a xerographic developing material containing toner particles with an electrostatic charge is caused to sprinkle over drum surfaces, whereby the toner particles adhere to the electrostatic latent image to form a seam-shaped xerographic powder image. as the document. The exposed and developed portion of the xerographic drum is then advanced to the image transfer location D, where it receives a sheet of carrier material which is advanced by the separation rollers 61 and transported into contact with the drum by the sheet conveyor 62. As the drum surface and the sheet of carrier material pass over the corona transfer device 64, the developed powder image transferred electrostatically from the xerographic drum surface to the sheet of carrier material. The xerographic drum then continues to rotate past the corona cleaning device 84, then to the web cleaning device where any powder residue on the drum surface is removed by the web, and then under the discharge lamp, where any charge r»Bt on the drum is discharged by the radiation from this lamp.

In the meantime, the copy drum will have rotated at a corresponding rotational speed, during which it will request a document to be delivered, if the intermediate pin is in such a position that the document is ejected, and the copy drum is then ready to receive another document, or if the document is to be retained on the copy drum , it is ready to be moved past the exposure site again. Assuming that only a single copy of a single document is produced, the copy will be fed out of the machine and the xerographic powder image will be transferred to the sheet of the carrier material during one rotation cycle of the xerographic drum cg copy drum. At this point in the operation of the apparatus, however, the sheet of carrier material to which the powder image has been transferred will not yet have exited the machine.

The duty cycle of the described apparatus is such that three revolutions are required for the xerographic drum and the copy drum to achieve one and a half revolutions for the sheet transporter mechanism. In the embodiment of the apparatus shown, the length of the chain in the sheet conveyor is twice the circumference of the xerographic drum, so that the chain makes one and a half revolutions for three revolutions of the xerographic drum.

Therefore, after the transfer step, the xerographic drum and the copy drum, even if no hard copy is to be produced, must be rotated through a second and third revolution to enable the sheet conveyor to feed a sheet of carrier material from the machine, While still assuming that only a single copy is to be produced, the optical system during the second and third revolutions of the xerographic drum and the copy drum will in practice scan a blank copy drum and project a radiation image from the copy drum onto the xerographic drum, so that this image of the xerographic drum is exposed on the copy drum. The xerographic drum will then again pass past the developing site and through the transfer site, as described above; however, a locking mechanism now engages the chamber arm 277 (Fig. 18) to prevent the advance of a sheet of transfer material from the paper trough to the xerographic drum. As the xerographic drum continues to rotate through the second and third revolution cycles, it will clean again as it passes the cleaning location E, and is then completed for an actual coupling cycle.

Smooth continuous operation of the sheet conveyor, the copy drum and the xerographic drum is achieved by means of a timing control which, when actuated by the lfiss mechanism, operates in such a time setting in relation to the xerographic drum's rotation, that sufficient time will elapse for the xerographic drum to be allowed to to rotsrs the revolutions required before the main drive motor disengages, whereby the sheet conveyor mechanism and delivery rollers will

Be able to issue the copy from the machine.

As shown in figures 14, 18, 19 and 20, the timing cam 630 is mounted on a shaft SH11 which is supported in the frame plates 11 and 12. The timing cam is supported on the shaft SH11 so that it can rotate in relation to this shaft, and is held in the axial direction on the shaft of a retaining ring placed in a suitable groove formed on the shaft. The shaft 3H11 is drive connected to the drum shaft SH1 via a belt 96 which runs around pulleys 95 and 94 which are attached to the shafts SH11 and SH1 respectively, whereby the shaft SH11 will rotate at approximately one third of the rotational speed of the shaft SH1.

The timing cam is equipped on one side with cam surfaces 631 and 632 which are designed concentrically with each other, and which are used to actuate a limit switch 12LS for issuing several copies, as well as a limit switch 9LS for the main operation. On its on-circuit surface near these cam surfaces, the timing cam is provided with a cam surface 633 which is adapted to actuate a limit switch 8LS for a purpose which will be described hereinafter. The limit switches 9LS and 12LS are mounted on a support piece 646,

and the limit switch 8LS is mounted on a carrier piece 647, and both of these carrier pieces are attached to the frame plate 11.

The timing cam is rotated during the timing cycle in the same direction and synchronously with the drum shaft by a coupling slide 540' which is mounted on the shaft SH11. The timing cam and the coupling slide form a locking coupling, that is, the coupling slide is provided with a tab 641 which is adapted to engage with one of the slots 634 formed on the projecting annular inner portion of the timing cam, and the coupling slide is axially displaceable on axis SH11 for engagement with the timing cam.

The coupling slide 640 is held so that it will rotate together with the shaft 11 by a radial pin 644 which is carried by the shaft engaging with a longitudinal slot 642 located in the hub of the coupling slide. The coupling slide 640 is equipped with an annular groove 643 which is adapted to receive the locking arm in the locking mechanism which will be described in the following, whereby the coupling slide can be guided selectively into or out of engagement with the timing chain.

To ensure rotation of the timing cam in the opposite direction, a return spring 651 is provided which surrounds the hub of the timing cam. One end of the return spring is engaged in an opening in the rarwae plate 11, and the opposite end part of the return spring is engaged in a suitable opening in the timing cam.

It will be noted that the size of the return spring is such that when the spring is in its normally expanded state, it can be compressed when the timing cam is turned counterclockwise, as seen in fig. 5, whereby sufficient energy is stored by the spring to be able to turn the timing cam clockwise, when the driving force, i.e. the coupling slide 640,

which turns the return spring counter-clockwise, is relieved.

The rotation of the timing cam clockwise,

as can be seen in figures 5 and 19, is limited by the engagement between the stop pawl 635 which extends axially from the counting cam 636 which is also formed on the timing cam, and the stop 652 on the end of the cam stop arm 653. The cam stop arm is supported on a shaft pin 654 which is attached to the frame plate 11 and is normally pressed by a spring 655 counterclockwise," as seen in the aforementioned figures, into contact with the stop pin 656 attached to the frame plate 11. In order to delay the movement of the timing cam, when it is rotated clockwise by the return spring, it is placed on the timing cam is a toothed wheel section 637, the teeth of which cooperate with a swinging part 656 which is supported rotatably on a spindle 657. With this arrangement, the moment of inertia for the timing cam, when it is returned to its normal position, which is determined by the device for the stopper paw against the stop , is partly absorbed by the swinging part, and not exclusively by stops the erlab 635, when this strikes against the stop 652.

The locking mechanism used to prevent the advance of sheet transfer material during the machine's timing cycle and to provide operation of the timing cam comprises a coupling arm bracket 661 which is attached to a U-shaped bracket 662 which is attached to the frame plate 12. A fork-shaped release arm consisting of two L-shaped arms 663 held at a distance from each other by a spacer 664 and a rod 665" are rotatably mounted on a pivot pin 666 which is located in the coupling arm bracket 661. As will be seen, the spacer 664 surrounds the pivot pin 666.

At one end, the arms 663 engage with the annular groove 643 in the coupling slide 640, and at the other end engage with a pivot pin 667 which is placed in the link arm 668. The link arm 668 is connected at one end to the fork-shaped armature in the normally de-energized cam release solenoid SOLI which is attached to the bracket 662.

At its other end, the articulated arm 668 is provided with an opening

which occupies one end of a spring 671, the opposite end of which is attached to a spring pin 672 which extends from a bracket leg 662, whereby the arms are normally pressed against the clockwise direction, as seen in fig. 18, so that the coupling slide is pressed into engagement with the timing cam.

A locking piece 673 is attached to the fork-shaped release arm in such a position that it engages with the locking portion 279 of a cam arm 277, whereby the locking piece 673, when the cam release solenoid SOLI is de-energized as shown in Figures 5, 18 and 19, will engage with the locking part 279 on the chamber arm 277, so that this arm is locked in an inactive position. When the cam arm 277 is in its inactive position, the roller 278 on this will be lifted up by engagement with the roller control cam 261 on the drum shaft SH1, whereby the separating rollers 61 are prevented from falling down into contact with the stack of carrier material in the paper trough. Although the separation rollers are rotated to advance a sheet during each rotation cycle of the xerographic drum, the sheet material will not thus advance when the xerographic drum is rotated during the machine's timing cycle.

In order to enable an operator to determine the number of copies produced during a certain period of time, for example a day, a conventional mechanically actuated counter 674 is provided which is mounted on a chain 675 which is attached to the frame plate 11 by the back of the machine, in such a position that it is accessible to an operator.

Because the number of revolutions of the xerographic drum and its associated elements will vary, according to the number of copies produced, due to the two additional rotation cycles of the xerographic drum when the machine is set to finish, it is clear that a number for the number revolutions made by the xerographic drum during a certain period of time will not be an accurate indication of the number of copies produced during that period of time.

The only accurate indication of the number of copies produced during a given period of time is the number of sheets of carrier material advanced into transfer contact with the drum during the specified period of time.

In order to count the number of sheets that are advanced, a sheet mechanism is provided which only affects the counter during an actual advance cycle or copy cycle, but not during the finish cycle.

As shown in figures 5 and 14, a counter arm 631 is arranged which is pivotably mounted on an axle pin 682 which is attached to the frame plate 11.

A pair of cam followers 683 and 684 are mounted on the counting arm on the opposite side of its pivot axis, the cam follower 683 being arranged to be influenced by the counting cam 636 (Fig. 19) which is formed on the timing cam 630 (Fig. 20), while the cam follower 684 is arranged to be acted upon by a counting cam 685 which is attached to the drum shaft SH1.

A spring 686 is connected at one end to the counting arm 681 and at its other end to a pin 687 which extends from the frame plate 11, so that it presses the cam followers 683 and 684 legs against their respective cooperating chambers.

A drive pin 688, which is attached to the end of the counter arm

681 opposite the cam follower 683, engages with a suitable opening in the trigger arm for the counting mechanism 674, whereby the counting mechanism is affected when the counting arm is swung.

As a sheet is advanced by the paper feed mechanism described above during a copying cycle, the cam follower 684, upon engagement with the counting cam 685, will cause the counting arm to rotate clockwise, as seen in Fig. 5, to actuate the counting mechanism. During the copying cycle, the timing cam 630, which has previously been released, is in its normal position with the falling part of the counting cam 636 close to the cam follower 603 on the counting arm.

When the timing cam is rotated during the closing cycle to the position shown in fig. 5, the rising part of the counting cam 636 will engage with the cam follower 683 on the counting arm so that the cam follower 684 is lifted out of engagement with the counting cam 685, so that the influence of the counting mechanism is prevented during the period when the separating rollers are prevented from being in contact with the stack for the presentation of a sheet, as described earlier. ;

When the intermediate pin 151 is in its working position, as shown in Fig. 3, as previously described, the rocker shaft 143 which carries the gripper fingers 142 is automatically affected during each rotation of the copy drum, so that a document held by the gripper fingers is released to be emitted from the machine, and the gripping fingers are kept open long enough to be able to receive a new or different document. This is the mode of operation when the machine is set to produce a single copy of an original, or when successive copies are produced from successive originals.

When a plurality of copies are made from an original, it is desirable to retain the original on the copy drum during successive copying cycles, rather than the operator having to insert the original into the machine again for each copying.

In order to make it possible to retain the document on the copy drum while a plurality of copies are being produced, the intermediate pin is moved out of working position in relation to the rocker shaft by an operator, by the latter acting on a control button 6 in a programming mechanism. The programming mechanism contains a control knob 6 which is attached to a control shaft 601 which is rotatably and displaceably stored in a bracket 603 which is attached to the frame plate 11. The control knob is equipped with a numbered scale, so that the operator can set the number of copies desired, as the operator for example, in the embodiment shown, the machine can be set or programmed to produce from one to 10 copies from an original.

By means of a pin 604 and a holder 605, an intermediate cam 602 is attached to one end of the steering shaft 601, which is used to put the intermediate pin 151 into operation, the latter ensuring operation of the gripper fingers on the copy drum 30, as described above. The intermediate knob 602 is placed on the control shaft so that the pitch of the cam is in such a position that the trigger arm 161 is affected when the control knob 6 is turned to produce a plurality of copies, that is, when the control knob is set to produce from two to ten copies. With the intermediate cam thus placed on the guide shaft, the falling part of the cam will be close to the release arm when the control knob is set for the production of individual copies, that is, when the number 1 on the scale is at the position of the number 12 on a dial.

A pawl wheel 606 is attached to the steering shaft between the steering knob and the front leg of the bracket 603. A pawl plate 607 is mounted loosely on the control shaft between the pawl wheel 606 and a retaining ring 608 which is placed in a suitable groove formed in the steering shaft.

A step-by-step turning movement is transmitted to the pawl wheel by a cam 609 which is fixed to the shaft SH2 which carries the copy drum, this cam acting against a roller 611 which is carried by an arm 612. The arm 612 is pivotally supported on a shaft pin 613 which is fixed to the rear overflow ear on the rear leg of the bracket 603 (fig. 17) and is equipped with a drive pin 614 which is displaceably engaged in the slotted end of the pawl plate 607. A spring 615 is attached at one end to the arm and at its other end to a pin 616 which is attached to the frame plate 12, and the arrangement is such that the arm is tilted by the cam

609 in one direction during each revolution of the copy drum, while the return movement of the arm in the opposite direction is produced by the spring 615.

The pawl plate 607", which is pivoted concentrically with the pawl wheel 606, carries a spring-loaded driving pawl 618 with associated spring 617, and the same pawl is arranged to engage with the teeth of the pawl wheel 606, so that the pawl plate, when tilted back and forth, will turn the pawl wheel at a stepwise movement.

During its return stroke, the pawl 613 will strike against a pawl lifting pin 619 and thereby be lifted out of engagement with the pawl wheel. When the machine is at rest, the pawl is in a position out of engagement with the pawl wheel, whereby the operator can turn the control knob 6 so that the machine is set to produce the desired number of copies.

The steering shaft 601 is normally pressed towards the front of the machine, to the left as seen in fig. 15, of a coil spring 621 surrounding the steering shaft. One end of the coil spring rests against the rear branch of the bracket 603, and the opposite end of the coil spring rests against a stop disc 622 which is retained in the axial direction on the steering shaft by a pin 604a.

A stopper 623 (Figs. 15 to 17) is attached to the rear branch of the bracket opposite the coil spring, The stopper is provided with a large notch or stop portion which forms a zero position, as well as a series of angularly offset, small notch or stop portions, these latter being present in a number of one less than the maximum number on the number scale of the control button 6. Accordingly, the stop in the embodiment shown is equipped with nine small incisions or stop portions. A stopper pin 624 extends radially from the steering shaft to cooperate with the stopper, as described below.

The number of teeth on the pawl wheel 606 is also one less than the highest number on the number scale on the control scale 6. In the shown embodiment, where the control button is calibrated with a number scale running from one to ten, the pawl wheel 606 is therefore equipped with nine teeth.

When it is desired to produce more than one copy from an original, the mechanism is set by pushing the control knob 6 inward and simultaneously turning it to indicate the number of copies desired. When the control knob is pushed in and turned clockwise as shown in fig. 15, the stopper pin 624 on the steering shaft will be turned into engagement with a small notch on the stopper, corresponding to the set number on the steering knob minus one. The pawl wheel is also turned by turning the steering shaft in a corresponding ratio to the numbered scale on the steering knob. At the same time, the intermediate cam 602 is rotated to actuate the arm 161 so that the intermediate pin is withdrawn from its working position, and the intermediate cam is moved rearward and out of engagement with the multiple copy limit switch 7IS mounted on the bracket 603, for a purpose that will be described.

When the machine is put into operation, the copier drum will rotate, and during each rotation of the copier drum, the pawl wheel will be advanced one step, counter-clockwise, as seen in fig. 15. If the pawl engages with the last tooth on the pawl wheel, it will turn the steering shaft sufficiently so that the stop pin will slide off the shoulder of the stopper and fall into the large notch or zero position on it. When this occurs, the compressive force from the coil spring will press the control shaft forward and lock the stop pin 624 in the nulling of the stop 623 and cause the intermediate cam to move into contact with the multicopy limit switch 7LS.

Referring now to Figures 16 and 17, it will be noted that when the intermediate pin 151 is in its working position in relation to the arm cam 148 on the rocker shaft 143, the locking stopper 115 on the shaft 101, which carries the document stoppers 107 and the pressure fingers 106, will clear the end of the intermediate pin 151", whereby the rocker shaft and the associated elements will work in the manner described above.

If the intermediate pin 151 is moved out of working engagement 3 relative to the rocker shaft for the production of a plurality of copies, it is placed in such a position that it interferes with the locking stopper 115.

When a document is fed into the machine, the elements on the shaft 101 will retain and guide the document as described above, but as soon as the shaft 101 is turned to release the document, the locking stop will be turned sufficiently to engage the intermediate pin, which means that it will move from the position shown in fig. 9 to the position shown in Figures 13 and 17.

the locking stopper 115 contains an arm 116 which is attached to the shaft 101. A locking piece 118 which is acted upon by a spring 117 is pivotally attached to the arm 116 whereby the locking piece 118, when the shaft 101 and consequently the arm 116 is moved in a clockwise direction as seen in fig. 9" will be tilted on its pivot so that it slides past the intermediate pin 151. Return movement for the shaft 101 and the arm 116

in the clockwise direction is prevented by the fact that the locking piece 118 strikes at one end against the intermediate pin, while the opposite end of the locking piece strikes against an ear 119 on the arm 116, whereby the document stoppers 107 and the pressure fingers 106 are kept out of engagement with a document on the copy drum.

A clearer understanding of the operation of the apparatus can be easily obtained by referring to the schematic connection diagram and by referring back to the working characteristics of the machine elements described above.

Before the xerographic apparatus can be put into operation, the removable panels in the housing which enclose the apparatus must be placed in the closed position so that the locking switches 1LS, 2LS and 4LS, which are mounted on the apparatus frame not shown, are affected. These locking switches are used so that the machine can only be put into operation when the removable panels in the housing are in place. This arrangement is made not only for safety reasons, but also to ensure proper air circulation inside the house to remove the heat produced by the projection lamps and the melting device. In addition, the paper trough and the developing device must be in place in a working position in relation to the other elements in the machine, so that the limit switches 3LS and 13LS respectively are closed.

The entire device assembly is supplied with power by closing the switch SW1, which connects the assembly via limit switches 1LS, 2LS, 3LS and 4LS with a suitable power source, for example a normal mains supply of 120 v. It and 60 period alternating current.

By closing the switch SW1, the machine is put into a ready-to-operate state which is indicated by an indicator lamp LMP1 which is supplied with current via the transformer Tl. The resistance heating elements RI and 2

in the heat melting device 70 current is supplied through the normally closed thermostat THS2. The machine is kept in the ready-to-operate condition for a sufficient period of time for the heat-melting device to reach its normal working temperature. It is noted that the motors MOTI and M0T4 which drive fans, not shown, are connected in series with the normally open thermostat THS1 directly across the line, so that these motors can be put into operation when the temperature inside the house rises.

Referring now to fig. 5 shows the relative location of the control components in the machine and some of the electrical components that contribute to the time setting of the machine, in the machine's ready-to-operate state. The drum pulse switch 5LS

is affected by the drum pulse cam 154 attached to the copy drum shaft SH2. The drum pulse cam 164 is arranged on the shaft so that the drum pulse switch 5IS is open at the time when the machine is switched off, which is why this switch is open when the machine is in a ready-to-operate state. The drum pulse switch is in reality a locking device which makes it possible to actuate the cam release solenoid SOLI, when successive copies are made as described below.

In the ready-to-operate state of the machine, the cam release solenoid buLl is de-energized, allowing the spring 671 to push the arms 663

in such a position that the coupling slide 640 is held in engagement with the timing cam 630, and that the separating rollers 61 are locked up over the previously described joint connection. In the ready-to-operate state, the timing cam 630 is in its outermost turning position, as shown in fig. 5.

When the timing cam is in this position, it affects limit switches 8LS, $ IiS and 12 LS. When the limit switch 8LS is actuated by the timing cam, its normally open contact 8LS-A is closed and its normally closed contact 8LS-B is opened. In this position for the timing cam, the normally open contact 9LS-A is closed in the limit switch 9LS, and the normally closed contact 9LS-B is open. Likewise, the normally open contact 12LS-A of the multiple copy limit switch 12LS is closed, and its normally closed contact 12LS-B is open.

When that document is introduced into the machine through the document guide, the document sensing switch 6LS is affected so that its normally open contact is closed. This switch will, through the contact 9LS-A in the limit switch 9LS, which is closed in the ready-to-operate position, the normally closed contact 11LS-B at the end of the path limit switch ULS and the closed contact 12LS-A, make it possible to energize the cam release solenoid SOLI. When the cam release solenoid SOLI is energized, it will, by the action of the arms 663, pull the switch slide 640 out of engagement with the timing cam 630, whereby the timing cam is allowed to rotate back to its normal position by the action of the return spring 651" as described above.

When the timing cam returns to its normal position, the respective cam faces on it will slide off the triggers for the limit switches 8LS, 91S and 12LS. At this time, the main drive motor M0T3 is energized, through the now closed contact 9LS-B in the limit switch 9LS, so that the xerographic drum 20, the copy drum 30 and the arm conveyor mechanism 62 are set in rotation. The melting device solenoid S0L2 is energized so that the locking plate in the hot melting device 70 is opened. The discharge lamp LMP6, a fluorescent lamp, is energized through its circuit consisting of a ballast L5 and starter switch S3. Power is also supplied to the high voltage source PSI to provide operation of the corona charging device 21, the corona transfer device 64 and the corona purification device 84. Upon opening the contact 9LS-A, the cam release solenoid SOLI is de-energized.

At the same time, the indicator lamp LMP11 for "wait with setting" will be supplied with power through the transformer T3, as this lamp is used to indicate to the operator that the machine is now carrying out a work cycle and that the operator should not turn the control knob 6 at this time.

Within a very short time after the switch 9LS-B is closed, the contact 81S-B of the limit switch 8LS is closed so that the motor M0T2 is energized across the closed limit switch 13LS, to operate the developing apparatus 50 and the toner delivery device 54, and to energize the transformer T2 so that current is supplied to the filling lamps LMP4 and LMP5. At this point, the contact 8LS-A in the limit switch OLS is opened, whereby an overvoltage from the secondary winding in the transformer T2 is allowed to pressurize the wire that supplies current to the fluorescent lamps 1MP-2 and LMP-3 through the current circuits consisting of the ballasts or resistors LI, L2 and L3» L4, as well as the starters Sl and S2, respectively. Prior to the opening of contact 8LS-A, in a ready-to-operate condition with transformer T2 not energized, line voltage is normally applied to this circuit for fluorescent lamps.

When the cam release solenoid SOLI is energized to release the clutch slide 640, it will also release the cam arm 277, whereby its rollers 278 will fall onto the surface of a roller guide cam 281, which is attached to the shaft SH1.

When the timing cam rotates off of limit switch 12LS, contact 12LS-A will open, interrupting the wire to the cam release solenoid SOLI, which was previously de-energized by opening contact 9LS-A.

When the comb release solenoid SOLI was energized, it caused the cam arm 277 to be released, bringing the roller 278 thereon into engagement with the paper feed cam 281. When the comb release solenoid SOLI is de-energized by the opening of contact 9LS-A, the arm will

663 in the locking mechanism be pressed by the spring 671 in a clockwise direction as shown in fig. 18, but its movement will be blocked by the locking portion 279 of the chamber arm 277 in contact with the surface of the locking piece 673. When the movement of the arm 663 is blocked in this way, the coupling slide 640 will not have moved sufficiently to the left, as shown in the aforementioned figure, to that the pawl 641 on the coupling slide will engage in one of the slots 634 on the timing cam 630.

It is noted that during the production of simple copies of documents, the programming mechanism is set to its zero position, which means that the number one on the control knob will be in the position of the number twelve on the dial. As described above, the normally closed limit switch 7LS is open when the programming mechanism is in its zero position.

At the end of a paper feed cycle, the paper separation rollers are lifted

61 of the paper feed cam and when the roller 278 rises on the paper feed cam 281, the locking part 279 on the cam arm 277 will slide off the surface of the locking piece 673 and come into engagement with the locking piece.

When the locking part 279 slides off the surface of the locking piece 673, • the arms 663 can be pressed by the spring 671 to their outermost positions in a clockwise direction, whereby the coupling slide 640 will be moved sufficiently to the left, to the position shown in fig. 18,

to engage the timing cam 630 to ensure that this timing cam rotates. The action for locking the chamber arm 277 prevents the paper feed system from feeding additional sheets.

After approximately 300° rotation of the xerographic drum from the time the clutch slide engaged the timing cam, the timing cam will have rotated sufficiently to again actuate limit switch 12LS and then limit switch 8LS. This causes the contact 8LS-B of the limit switch 8LS to open, de-energizing the developing drive motor M0T2, the transformer T2 and the lamps LMP4 and LMP5. Normal mains voltage is now supplied to the circuit for the fluorescent lamps, which consists of lamps LMP2 and LMP3 and their associated ballasts and starters.

With continued rotation of the timing cam 630 (fig. 20), when it reaches its position for ready-to-operate condition, as shown in fig. 5, actuate the limit switch 9LS so that its contact 9LS-B opens3, whereby the main drive motor M0T3 and associated elements are de-energized. The machine is again in a ready-to-operate state, and a copy cycle can be started again, simply by inserting a document into the document guide so that the document sensing switch 6LS closes, after which the cam release solenoid SLOI is re-energized to start another copy cycle.

The operation of the machine during the production of copies of successive documents which are fed into the machine will now be described, the operation of the machine when inserting the first document is identical to what has been described previously. If another or a further document is introduced into the machine immediately after the first document has been grabbed by the copy drum for introduction into the machine, the document sensing switch 6LS will be held in the closed position by the second document.

The machine will now undergo the sequence of work previously required during one complete revolution of the xerographic drum. At the time when the drum pulse switch 5LS is closed at the second rotation cycle, the document sensing switch 6LS is still kept closed by the second document waiting to be received by the machine. Since the document sense switch 6LS is closed, closing the drum pulse switch 5LS will re-energize the cam release solenoid SOLI, thereby releasing the clutch slide 640 from the timing cam 630 and releasing the paper lock mechanism to allow another paper feed cycle. At approximately 240° rotation of the xerographic drum from the beginning of the first copy cycle, the paper feed arm will therefore be unlocked, as described earlier. At the same time, timing cam 630 has begun its closing cycle and will have actuated switch 12LS to close its contact 12LS-A, prior to closing drum pulse switch 5LS. By closing the drum pulse switch, while still closing the document sense switch 6LS and closing the contact 12LS-A again, the cam release solenoid SOLI is energized to release the paper feed cam 277 (Fig. 5), and to release the timing cam 630, allowing it to rotate back to its normal position.

The machine has now been reset and start; r a completely new copy cycle. If no further documents are entered into the machine, it will be disconnected as described earlier. If at any time during the disconnection cycle another document is introduced into the machine, the document sensing switch 6LS will be closed by this document. The document will be held in the document guide until it is grabbed by the gripper fingers on the copy drum. The next time the drum pulse switch 5LS is closed, it will cause the machine to perform another cycle, as described above. Accordingly, the machine will reset and begin a new copy cycle each time the drum pulse switch 5LS is closed, provided that the document sensing switch 6LS is closed at the same time.

Por to produce a plurality of copies from an original will

, the operator presets the programming control knob to the ^desired number of copies before the document is fed into the machine. The effect of turning the programming control knob to an arbitrary ; of the numbers from two to ten will mean that the multicopy switch 7LS is closed. The intermediate pin 151 is also drawn to an iri_

■active position by turning the programming control knob 6, as already described above. The start-up of the machine and the recording of the document will take place in the same way as for a single document. The multiple copy switch 7LS will in practice close a hole for the cam release solenoid SOLI, whereby this solenoid is held

energized for as many periods as necessary to copy the required number of copies. By keeping the cam release solenoid energized, the cam arm 277 is prevented from unlocking as described above, allowing the paper feed system to feed a sheet of paper with each revolution of the xerographic drum. The cam release solenoid SOLI also keeps the clutch slide 640 out of engagement with the timing cam 630, keeping the machine in continuous operation.

At about half a drum revolution before the end of the copy cycle where the last copy desired is exposed, the programming mechanism will be returned to its zero position as described above, thereby opening the multiple copy limit switch 7LS, while allowing the intermediate pin 151 to return to its normal working position. .Lette prepares the machine for shutdown by de-energizing the cam release solenoid SOLI to enable shutdown of the machine and to allow the gripper fingers on the copy drum to open to feed the document from the machine. The machine will now be switched off in the usual way, as described earlier.

In the hblder circuit, a switch 12LS is inserted together with the multi-copy limitation switch 7LS. The contact 12LS-B in this switch is closed during part of the machine's duty cycle, and its main function is to prevent the current surge from the developing drive motor M0T2 and the filling lamp circuit from propagating through the document removal switch 6LS, which is designed for a rather low amperage.

Contact 12LS-A, which is opened by the return of the timing cam before the drum pulse switch 5LS is closed, prevents the cam release solenoid SOLI from being energized too early by the drum pulse switch 5LS being closed during the first revolution cycle of the copy drum.

In the machine's electrical circuit, a limit switch 10LS for low paper supply is inserted, and this switch is placed so that it is affected or closed by a paper switch arm 254 which is attached to the drive tube 253, whereby this switch is closed, when the supply of sheet material in the paper supply trough is exhausted. When this limit switch is closed during machine operation, it will energize a solnoid S0L3 which is a common buzzer mechanism, not shown.

Likewise, a limit switch ULS for track ends is inserted in the electrical circuit. This limit switch is located close to the take-up roll 83 for cleaning, whereby the material is advanced into contact with the xerographic drum to remove powder material residues remaining on it, and will be wound up on the take-up roll. When the web material is wound up on the take-up roll 83 (fig. 1), the effective diameter of the material on this roll will increase in direct proportion to the reduction in the amount of web material remaining on the supply roll. When, therefore, the supply of web material on the supply roll 83 is almost exhausted, the diameter of the material on the take-up roll 83 ba will be increased sufficiently, whereby the web material will come into contact with the trigger for the limit switch ULS. When this happens, the normally open contact 11LS-A will be closed so that small indicator lamps LMP7, LMP8, LMP9 and 1MP10, which are arranged in a group under an indicator panel made of glass or other suitable material below the switch SW1, will be closed and thereby indicate to the operator that the railway should renew the supply of railway material in the machine. These indicator lamps can only be energized when the machine is in the ready-to-operate state, as the contact 11LS-A in the limit switch ULS is located 1 the contact 9LS-A in the limit switch rsn 9LS, which is only closed, when the machine is in the ready-to-operate state. When the contact 11LS-A is closed, as described above, the normally closed contact 11LS-B is opened, whereby it is prevented that the machine is put into operation again, until the supply of track material is renewed.

Claims (10)

1. Xerographic copying apparatus for producing several copies one after the other, equipped with a drum (20) with a photoconductive surface on which, in order to produce an electrostatic latent image, an optical image of an original to be copied is projected onto the surface of this drum during its rotation passes past a number of processing locations and where the apparatus contains controllable grippers in connection with a rotatable original carrier (30), characterized in that it comprises a control system with a counter (6, 623) which sets a previous setting in accordance with the dst number of copies to be copied causes that the control system remains in a first position with active grippers (142, fig. 4, 6-13) until the production of the last copy and then causes the control system to take a second position with inactive grippers so that the document is released from the original carrier (30) in during the production of dsn last copy. 2. Apparatus in accordance with patent claim 1, characterized in that the control system comprises a spring-loaded (621) shaft (601, fig. 15) mounted for rotation and for axial movement, as well as a cam (602) attached to the shaft (601) and operatively connected with an intermediate part (151" fig. 4) which affects the grippers (142). 3. Apparatus according to claim 2, characterized in that the shaft (601) carries a projection (624) for engagement with a stopper (623) which surrounds the shaft (601) and which carries an extended recess which allows the shaft (601) to move itself axially in relation to the Btopper (623) when the projection (624) is in line with the extended notch. 4. Apparatus in accordance with patent claim 3" characterized in that a pawl wheel (606) is attached to the shaft f 601) to which a step-by-step rotational movement is transmitted from drive means associated with the original carrier and the drum. 5. Apparatus in accordance with claim 4, characterized in that the stopper (623) carries a number of smaller cutouts in the same number as the number of teeth on the pawl wheel (606). 6. Apparatus in accordance with claim 4, characterized in that the shaft (601) carries a control knob (6) with which the shaft (601) can be turned by hand to thereby change the position of the projection (624) to different angular positions in relation to the stopper (623 ) thereby changing the number of copying cycles performed within the comb (602) will cause the intermediate part (151) to affect the grippers. 7. Apparatus 1 according to one of claims 1 to 6, where the rotatable original carrier is a carrier drum (30) which moves synchronously with the xerographic copying drum (20) as they are driven by a common drive device, characterized in that in in connection with this, a coupling-actuated control means (630, fig. 20) is arranged to ensure operation of the xerographic copying drum (20) during an exhaust cycle, the coupling-actuated control means (630) being controlled by the control system. 0. Apparatus in accordance with claim 7, characterized in that the control member affected by the coupling is a cam (630) which interacts with a. coupling slide (640). 9. Apparatus according to claim 8, characterized in that the coupling part (640) is brought into and out of engagement with the cam (630) under the influence of a solenoid (S0L-1) which is controlled by a holding circuit containing a limit switch (7LS) which is triggered by the cam (602). 10. Apparatus in accordance with claim 9, characterized in that rotation of the shaft (601) causes the cam (602) to simultaneously close the limit switch (7LS) and to move a swing arm (161) which in turn moves the intermediate part (151" fig. 4).