US3168026A

US3168026A - Apparatus for preparing photocopies

Info

Publication number: US3168026A
Application number: US776286A
Authority: US
Inventors: Limberger Walter
Original assignee: Lumoprint Zindler KG and Co GmbH
Current assignee: Lumoprint Zindler KG and Co GmbH
Priority date: 1957-11-27
Filing date: 1958-11-25
Publication date: 1965-02-02
Anticipated expiration: 1982-02-02
Also published as: DE1103762B

Description

,1965 w. LIMBERGER APPARATUS FOR PREPARING PHOTOCOPIES 1 m m w W k. M a M m U (I s R 2 m m Y B .0 g Km .0 vN MN 5* Mv m mm m Wm Wm M W mow m 9 l 5 2 0 N w l n v dit AGENT Filed Nov. 25, 1958 2 Sheets-Sheet 2 l l v .7N VE N TOR. k/ALTEK L [HBEAGER United States Patent 3,16%,326 APPARATUS FOR PREPARING PHOTOCOPIES Walter Limberger, Hamburg, Germany, assignor to Lumoprint Zindler KG, Hamburg, Germany Filed Nov. 25, 1958, Ser. No. 776,286 Claims priority, application Germany, Nov. 27, 1957, L 29,159; Dec. 20, 1957, L 29,329 16 Claims. (Cl. 95--75) The invention relates to an apparatus for preparing photocopies on sheet material by the difiusion method with illuminating and developing devices in the same housing, on one side of which parallel slots are arranged for the introduction of copying paper and the original document.

The invention, in one advantageous embodiment, is based upon an apparatus with a known surface lamp. Such surface lamps have previously been provided in combination with a developing device in the upper part of an apparatus with a cover covering the surface lamps, under which the illumination of the negative paper occurs. For introducing the illuminated negative paper together with the positive paper into the developing device, the cover must first be opened and the negative paper placed together with the positive paper and introduced through a special slot into the developing device. The use of a surface lamp has the advantage of a good illumination of the original, but also has the disadvantage that copies cannot be prepared by a continuous method. The usual arrangement of the surface lamps with an upwardly directed image support leads to difiiculties in heat dissipation, since these image supports are continuously heated by upwardly rising air.

Furthermore, return travel of the original in known apparatus operating with a surface lamp to the discharge side of the apparatus requires considerable space, so that the original is generally discharged at the opposite side of the apparatus. It is known to provide conveying devices, for example, which are guided round an illuminating device constructed as a cylinder and the dimensions of the apparatus and its consumption are thereby considerably enlarged and the dissipation of heat from the illuminating device is also rendered diflicult. Such a con struction was not previously possible for apparatus in which copies are prepared on sheet material by the diffusion method and all copy papers and the original were inserted simultaneously, i.e. the positive and negative papers with the original, when the negative paper lay directly on the illuminating device and the original only lay behind the negative paper.

Furthermore, there is the disadvantage in known apparatus that the positive and negative papers discharged from the developing device still contain considerable moisture. These papers, which are discharged adhering together from the developing device, must therefore be taken immediately and either conveyed to a special drying apparatus or separated so that drying can occur. Either a large consumption in view of the use of additional devices arises or much space is required and the drying lasts a considerable time.

The purpose of the invention is to avoid the disadvantages of known constructions.

This problem is solved in accordance with the invention in that on the image support of the illuminating device provided with known surface lamps one or more endless bands are arranged as conveying and counter-pressure means for the original and negative paper and are each guided around rollers arranged at each end of the image support, and the return run of the bands effects return movements of the original, which is guided to this run through a separating device, in the vicinity of the intro- 3,168,026 Patented Feb. 2, 1965 "ice duction slots. With this advantageous construction, the paper can be introduced in the manner described above and the original can be conveyed to a discharge slot, which lies between the introduction slot for the original and the negative paper and that for the positive paper.

A particularly advantageous construction is achieved by the elastic suspension of the separating wall between the return movement channel for the original and the introduction channel for the positive paper and the resilient pressing of this wall against the conveying belt. In a particularly simple manner, an apparatus construction requiring only a small space is given, in which a through illumination can be carried out at a surface lamp and the original is discharged at the operating side directly by its introduction slot.

In an embodiment of the device according to the invention, the original must be reversed by means of the separating device through a path turning the original through about A pneumatic separating device is advantageous for this purpose, with mutually opposite parallel suction slots on each side of the original which are one behind the other in the direction of advance and a nozzle, through which air is blown for the purpose of separating the leading edges of the original and negative paper. This nozzle extends preferably over the whole width of the original and the negative paper.

According to a further embodiment of the invention, holding devices are provided on one or more of the conveyer and pressure bands for the original, in which the original is insertable and which automatically close on passage of the original through the illuminating device and automatically open in the region of the discharge slot for the original. By such holding devices, a satisfactory guiding of the original in the region of the conveyer rollers arranged at the rear end of the illuminating support is ensured.

The holding means preferably consist of flaps which are connected with the band at their ends lying in the direction ofadvance. At the curved path of the one or more bands lying at the end of the illuminating device, a guiding member pressing the flaps on the band or bands is provided, so that the flaps serving as the holding device remain closed on curved guiding of the bands at the supporting rollers. This guiding extends in conformity with the curvature of the one or more bands from the illumination support of the illuminating device to the inlet of the return guiding channel for the original, in which the flaps are held closed by contact of the band against the guiding wall.

The guiding member is advantageously provided with a sharply pointed claw member facing opposite to the direction of advance, at which the negative paper is raised from the original.

The flaps are advantageously made integral with the conveyor belts or bands and are formed by slits made at an incline thereinto. According to another embodiment, the flaps consist of scoop-like plates arranged on one or more of the conveyor band-s which are made of synthetic material, for example nylon, and are advantageously transparent and, despite their elasticity, have a certain stiffness, which ensures their opening on release from the guide means. The transparent construction of the small plates ensures that the edge parts in pictures beneath the plates are copied.

Furthermore, a separator is arranged at the reversal point of the one or more conveying bands at the beginning of the illuminating device, which also includes a guiding surface from which the original is guided into its discharge slot. The separator is provided with guiding projections which engage between separate conveying bands or in longitudinal grooves in the conveying bands and release the forward edge of the original from the holding means, which open at this point, for example, due to the width of the guide channel.

According to an especially preferred embodiment, the invention provides the arrangement of the illuminating device with a known surface lamp under the ventilation openings provided in the substantially horizontal upper wall of the housing and a downwardly directed illumination support, wherein at the discharge slot of the develop ing device, which lies at the opposite side of the apparatus with respect to the side including the introduction slots, reversal means are provided which guide the copy paper in the direction toward the operating side of the apparatus and dispose it on a drying device. This construction has the advantage that operation of the device from the one side is possible. The operation is thus considerably simplified and the rapidity in the manufacture of copies is considerably increased.

The drying device for the copy papers discharged from the illuminating device is supplied with heat from the known illuminating device. Such a drying device in the manufacture of sheet material permits in a novel manner the utilization of the heat evolved in the illumination and provides the possibility that the copy paper need only be held and further treated after drying. A considerably more ready handling with respect to known apparatus is thus ensured.

Further advantages and features of the invention will appear from the following description of a constructional embodiment illustrated in the drawing. In the drawings:

FIG. 1 shows a longitudinal section through an apparatus, in which only the main parts are illustrated;

FIG. 2 shows a part view of the apparatus according to FIG. 1 from above;

FIG. 3 shows a section of the apparatus according to FIG. 1, for illustrating a preferred construction of the separating device;

FIG. 4 shows a side view in section of the essential parts of the device with an illuminating device and a developing device;

FIG. 5 shows a perspective view of the separator used in FIG. 4;

FIG. 6 shows an enlarged section of FIG. 4 for illustrating the separation of the original and the negative paper;

FIG. 7 shows a perspective part view of the part of the apparatus according to FIG. 4, for illustrating the separation of the original and the negative paper;

FIG. 8 shows a diagrammatic representation of the driving means for the device shown in FIG. 4.

All the apparatus is enclosed in a flat housing 1, along one side of which three parallel slots 2, 3 and 4 are arranged directly together. The outer slots 2 and 4 are provided with outwardly diverging inlets and are constructed as inlet slots. The original and the negative paper are inserted into the slot 2, whereas the positive paper is inserted into the slot 4. The original is discharged from the slot 3 after illumination. The slot 3 is made small. Its limiting walls 5 and 6 converge to reduce the outlet of the slot 3 conically, whereby the accidental insertion of a paper into the slot 3 is prevented, since in the selected form the paper to be inserted is diverted into the slots 2 and 4.

The simultaneous introduction of all papers and the original necessary for the preparation of copies has the advantage of a saving of time in the manufacture of copies and also the avoidance of intermediate illuminations, if as is necessary in known apparatus, the negative paper can only be brought into contact with the positive paper and inserted into the cover after the illumination.

In the upper part of the housing 1, the illuminating device 7 is arranged so that the illumination support 8, consisting for example of a glass plate, lies beneath the illuminating lamps 9 of the illuminating device. The

illumination is hence effected in the direction towards the base of the housing 1.

The chamber containing the illuminating device 7 is extended by an intermediate wall 11 extending above the developing device 10, under the upper wall 12 of the housing, to the discharge slot 13 of the developing device 18. The chamber containing the illuminating device 7 hence extends to the upper wall 12 over. a region which corresponds to the shape of the sheet material with which the copies are prepared. in this region, the upper wall 12 is provided with ventilation openings 14 through which the heat evolved in the illuminating device 7 passes upwardly from the apparatus or is blown out in this direction by a ventilator fan.

The insertion slot 2 for the original and the negative paper leads to the illumination support 8, under which the conveying device for the original and the negative paper is located. This conveying device consists of a conveyor belt-like apparatus. In the embodiment illustrated, a guide or driving

roller

15 or 16 is provided at the end of the illumination support 8, over which several endless textile bands 17 are stretched in side-by-side relation. The use of several bands arranged side-by-side ensures uniform contact over the whole width of the illumination support. The uniform contact in the longitudinal direction of the illumination support 8 is improved, since the glass plate forming the illumination support 8 is convexly curved in the direction of the conveying bands 17 in a plane parallel and perpendicular to the advance. The conveying bands 17, which merely guide from the start to the end of the illumination support 8, adapt themselves to the shape of the illumination support 8 in this way. In order to improve the contact even further, in an advantageous embodiment, the driving

rollers

15, 16 are guided in slots parallel to the surface of the illumination support 8 and are resiliently pressed together. In the embodiment illustrated, the arrangement is such that particularly the end part of the developing device 16 facing the illumination support 8 rises, so that the intermediate wall 11 can be constructed as an extension of the illumination support 8. By this, advantageous flow properties are given for the exit of the heated air via the ventilation openings 14, which lie in the vicinity of the discharge slot 13 of the developing device 10.

A separating wall 18 is resiliently suspended between the conveying bands 17. This separating wall lies between the channel to the return conveyor for the original to the discharge slot 3 and the inserting channel behind the insert slot 4 for the positive paper. The separating wall 18 is rigidly suspended at the

points

19 and 20 for example. At the latter point, it passes into the limiting wall 5 for the slot 3, whereas in the first-mentioned point it passes into a separating wall 21 between the

guide members

22 and 23 through the developer bath 24. The separating wall 18 is resiliently urged against the return run of the conveying belt 17. Since the separating wall 18 is constructed with a very smooth surface, the conveyance of the original to the discharge slot 3 is thus ensured.

The pressure on the separating wall 18 is effected in the embodiment illustrated by the conveying

rollers

25 and 26 for the positive paper. These conveying

rollers

25 and 26 run with the same direction of rotation as the driving

rollers

15, 16 for the conveyor belt 17. The

rollers

25 and 26, which are arranged substantially perpendicularly beneath the driving

rollers

15 and 16, are advantageously drivingly coupled by a simple belt drive, which is indicated at 27 and 28. The axes of the

rollers

25 and 26 are guided in substantially perpendicular slots, for example in the side walls. By the use of

elastic belts

27 and 29, for example of rubber, the

rollers

25 and 26 are drawn upwardly, whereby at the same time the separating wall 18 is urged against the return run of the conveyor belt 17. The lower limiting wall of the channel for the positive paper is formed by a rigid intermediate wall 29.

By the conveying arrangements according to: the invention, a construction effecting the pressing of the original and the negative paper against the illumination support 8 and, at the same time, the return movement of the original is provided, which requires extremely little space and, in the use of a surface lamp for illuminating by the through method, effects a return of the original in the vicinity of the inlet slot, although the transport device merely being arranged before the illuminating support 8 of the illumination device, i.e., is not guided round the illuminating device, and wherein the positive paper is inserted into the device at the same time as the original and the negative paper.

Behind the illumination support 8, a separating device for separating the original from the negative paper is arranged. This separating device is constructed as a pneumatic device in the embodiment illustrated. Within the scope of the invention, other constructional forms of such separating devices are included.

The separating device shown includes a suction box 30 behind the illumination support 8 and a further suction box 31 behind the upper run of the conveyor belt 17, in which a subpressure can be produced by the ventilator fan of the apparatus. These suction boxes, because of their divergent arrangement in the direction of advance in connection with a separating surface 32, leads to separation of the original from the negative paper, which continues in the path 22 to the developing device 10.

A dilferent and preferred construction form of the separating device is illustrated in an enlarged scale in FIG. 3. In this figure, the same parts are provided with the same references as in FIG. 1. In this construction, two suction boxes are provided one behind the other, which have at the facing sides several

parallel slots

44, 45 extending side-oy-side and in the direction of advance. Between the suction boxes provided with the

slots

44 and 45, a nozzle 46, projects from the side of the developing device 1t), through which air is blown on to the leading edges of the original and the negative paper emerging from the illumination support 8 in order to effect a separation of the papers. The combined effect of the

suction slots

44, 45 and the air jet from the nozzle 46 ensures a satisfactory separation at the most rapid rate of advance.

The nozzle 46 is supplied with air through a channel 47. The nozzle 46 preferably has the same width as the original or the negative paper.

Behind the guide or

path members

22 and 23 of the developing device 10, a pair of

pressure rollers

33, 34 is arranged, which on the one hand press out the moisture adhering to the papers and on the other hand cause their discharge through the slot 13. A pair of pressure rollers can be constructed in the usual way with elastic roller surfaces or with otherwise compressible rollers.

At the discharge slot 13, reversing means 35 are ar ranged. These reversing means consist in the embodiment illustrated of a curved guiding surface which can have the shape of a section of a cylindrical surface. The curvature is selected so that the paper emerging through the slot 13 is guided toward the region of the upper wall 12 of the housing 1, which is provided with ventilation openings 14 and which forms the drying device 43. The papers are thus directed toward the front side including the slots 2, 3 and 4, so that they can be readily removed from the operating side of the apparatus after drying by means of the air passing through the ventilating slots 14.

Beneath the intermediate wall 29, a space is located with the driving and connecting parts for the apparatus. For example, a driving motor 36 is provided which drives all the moving parts. These include particularly the driving

rollers

15 and 16 and the pair of conveying

rollers

33, 34, as well as the ventilator fan which is indicated at 37. The ventilator fan produces on the one hand the subpressure in the suction boxes 30, 31 and, at the same time, the stream of air through the nozzle 46 and also a ventilating air stream through the illuminating device 7, so that on cooling of the illumination support 8 the heated air is discharged upwardly through the ventilating openings 14 according to the arrow 38. The air coming from the ventilator fan can be guided laterally of the illuminating device 8 for example. According to another embodiment, the ventilator fan is arranged in the space 38, so that it blows on to the illumination support 8, whereby an air stream is set up which is distributed by baffle means and vortex formation to all the ventilation openings 14.

Beneath the intermediate wall 29, additional electric switching and connection means 96 are provided.

In operation, the original and the negative paper are introduced through the slot 32, the negative paper being disposed with the downwardly facing layer uppermost and the original with the upwardly facing picture or image downwards. The positive paper is inserted into the slot 4, together with these papers.

The original and the negative paper are separated, after moving towards the illuminating device 7, in the separating device 30 and 31, wherein the original is guided at the separating wall 32 corresponding to the arrow 40 toward the lower run of the conveyer belt 17 and is returned to the discharge slot 3 between the conveyer belts and intermediate wall 18. Teh illuminated negative paper passes corresponding to the arrow 41 into the path 22 of the developing device i At the same time, the positive paper passes into the path 23 of the developer device. With uniform driving of the driving

rollers

15, 16 and the conveying

rollers

25, 26, the diameters of the rollers are so chosen that the positive paper runs into the bath 24 simultaneously with the negative.

After leaving the bath 24, the positive and negative papers are discharged from the pair of

rollers

23, 24 in the direction of the arrow 42 through the slot 13 and are guided by means of the guide surface 35 over the ventilation openings 14, where a predrying of the papers occurs.

The surface of the upper wall 12 of the housing 1 delineated by the ventilation openings 14 forms the drying region 43, whose limits are shown in FIG. 2 by a dotted line.

FIG. 4 shows an overall view of the device according to the invention, wherein only the parts of an apparatus essential for the invention are illustrated. The apparatus is shown completely in FIG. 1.

The apparatus includes an illuminating device, of which two light sources 48 and 49 and an illumination support 50 curved concavely to the light sources are shown. The apparatus further contains a developing device, which consists of a bath 51, through which the positive paper is guided in a guiding path 52 and the illuminated negative paper in a guiding path 53. Behind the bath 51, a pair of drying and conveying rollers are located (not shown in the drawing), through which the negative and positive papers are discharged from the apparatus.

Slots are arranged in the side wall of the apparatus on the left as shown (which are not illustrated in detail in the drawings.) The uppermost slot 54 serves for introducing the negative with its layer downward. Through the slot 55, the original is inserted with the image upwards and the negative, with the layer facing upwards, is inserted through the slot 56. The discharge slot 57 for the original is arranged between the

slots

55 and 56. This slot narrows towards its outlet, so that accidental insertion of the paper into this slot is prevented.

The slot 54 is covered by a transparent guide wall 58, in an advantageous construction, which extends to the illumination support 50 of the illuminating device. The guide path for the negative paper is separated from that of the original by a further guide plate 59. This guide plate is also transparent, so that the guide path for the original can be seen from above. There is also a construction in which the

guide plates

58 and 59 are provided with openings, which permit control of the insertion of the original. The guide plate 59 extends with its ends facing the illuminating device to the vicinity of the illumination support 50 of the illuminating device. The spacing is so dimensioned with reference to the holding means constructed as flaps and described in greater detail below that these flaps cannot separate in the guide path of the negative paper.

Beneath the illumination support 50, a conveying and pressure device is provided consisting of a wide band or several smaller bands 60. The bands 60 are guided and driven by conveying

rollers

61 and 62 arranged at each end of the illuminating device. By the curvature of the illumination support 50, a suificiently strong pressing of the original against the negative paper and of both papers against the illuminating device is ensured, without supporting the bands 60 between the

rollers

61 and 62.

The return run of the bands 6t) extends along the preferably elastically arranged side wall 63, which at the same time is a limiting wall for the return guide path 64 of the original and at one side limits the discharge slot for the original. -The guide wall 63 is advantageously made curved. The guide wall is preferably curved upwardly, so that the pressure between the conveyer bands 16 and the guide wall 63 between the guiding

rollers

61 and 62 is ensured without special supporting means. Beneath the guide wall 63, a further guide path 65 is located, which terminates on the one hand in the slot 56 and on the other hand in the guide path 52 through the bath 51. The elastically suspended guide Wall 63 is carried at least in the region of the return run of the band 60 upon rollers 66, 67, which have an elastic surface or are yieldingly mounted in the vertical direction. These rollers 66, 67 serve to convey the positive paper to the lower side of the guide wall 63 and at the same time to press the guide wall against the return run of the bands 60.

In the embodiment shown, flaps are arranged in the band indicated in FIG. 4 at 60, as the holding means. These flaps are formed in this embodiment by slits in the surface of the band which are downwardly inclined in the direction of advance. One such flap is indicated at 68.

The band 69 is preferably a rubber belt with a fabric surface. A construction of rubber and also the stiffened fabric covering ensure that the flap 68 is spread open because of its elasticity on curving of the band 60, even if no special guide means are provided. Such an open position is shown at 68. It may be mentioned that the guide plate 59 is made so wide at the illumination support that the flap 68 cannot open in the guide path for the negative paper because of the curvature 61 at the leading end of the illumination support 50. The rounding off '69 serves for guiding the negative paper between the illumination support 50 and the band 60.

On passage of the band, for example, due to driving of the roller 61 in the direction of the arrow indicated, the band 60 runs under pressure along the illumination support 50. The flap 68 is thus pressed against the underside of the band over its whole length.

In the curved section at the return point of the band 60 at the roller 62, a claw section member 70 is provided as a guide which is sharply pointed at the end 71 facing the illumination support 50. This guide member 70 or its forward end 71 lies on the conveyer band 60 and prevents the flap 68 opening as a result of curvature of the band. An original held in the flap 68 is thus drawn with the band 60 round the roller 62, whereas a negative paper arranged on the original is raised upon the end 71 of the member 70 and guided into the guide path 53. This part of the process is illustrated on an enlarged scale and in perspective in FIGS. 6 and 7. The same parts are provided with the same references in this embodiment.

As shown in FIG. 6, the end 71 of the guide member 76 is pressed with a certain pressure against the band 60, which can be somewhat compressed in its thickness at this position. This pressure is provided merely in the region of the end 71 at which occurs the separation of the original 72 from the negative paper 73. In special constructions, such a compression is not necessary. It is to be noted, that the original, which projects into the band 60, cannot release its securement to this band and is consequently drawn along with the band 60. The negative paper 73 passes straight on and, particularly with a certain compression of the band by the forward end 71 of the guide member 70, passes to the upper side of the member and is consequently moved because of the advance into the guide path 53.

The same process is illustrated in FIG. 7. In PEG. 7, the band indicated at 69 merely has a relatively narrow width and is arranged in the middle of the guide path. Laterally of the band 60,

further bands

74, 75 are arranged. It should be expressly noted that, although only two further bands are shown in the drawing, several bands are advantageously arranged side-by-side. In the embodiment illustrated in FIG. 7, the illumination support is sharply curved upwardly at its end facing the developing device, whereby the negative paper, on leaving the gap between the conveying belts and the illumination support, is raised from the original and runs to the rear of the guide member 70.

The original is carried by the band 65 to the guide Wall 63 in the guide path 64. The upper limiting wall of the return guide path 64 is formed by a separator 76, one end of which divides the slots and 57 from one another. The end facing the band 60 includes a widened section, which is concave corresponding to the curvature of the roller 60. At the lower edge of the separator 76 facing the band, separating projections 77 are arranged, which can be seen best in Fiji. 5. These projections 77, in an embodiment according-to FIG. 7, engage for instance in intermediate spaces between the bands '74, 60 and or, in using a wide band, in longitudinal grooves in such band. The separating projections 77 are so constructed and of such length that they extend deeper than the flaps 68, i.e. the forward ends of the separating projection 77 are located nearer to the roller 61 than the deepest parts of the slits in the band beneath the flaps 68. On passage of the band, the separator projections 77 hence engage beneath the forward edge of the original and guide this to the discharge slot 57. It may be mentioned that the guide path 64 beneath the separating projections 77 is made of such a width that the flaps 68 can open freely, so that the original can pass out under these flaps. It is also to be noted that the flaps 68 are illustrated on an enlarged scale to facilitate the disclosure. The spacing of the concave surface 7 8 of the separator 76 from the band 60 is so large that movement of the band with the flap 68 open is possible at least at the lower edges carrying the middle projection 77.

In the use of the device described, various constructional forms are provided. One embodiment includes directly successive flaps 68 in one or more bands, wherein these flaps can partly overlap one another in scoop-fashion. This construction of the apparatus is particularly suitable for continuous operation, since the original is introduced with the band moving and is then gripped by the flap located at the start of the illuminating support and is held therein. According to another embodiment, a few flaps are arranged at a certain distance apart. In this embodiment, a stepwise operation of the process takes place, the conveyer band being driven until the original lies along the lower run of the conveyor band. In this position, an unused flap is located in the position of the flap indicated in FIG. 4 at 68, so that, on arrest of the band and while observing through the

transparent conductor walls

58 and 59, a new original together with new papers can be inserted. In the further operating step, the first original is discharged from the discharge slot 57, whilst the subseguently introduced original is guided along the guide wall An example of the construction of such a drive is illustrated in FIG. 8. This is fundamentally a drive in accordance With German Patent 923,112. The driving motor 79 operates on the one hand by way of a chain drive 80 to control the moving parts of the apparatus, for example, the conveyer roller 61. On the other hand, via a chain drive 8-1, an appropriate gear reduction mechanism 83 is driven and from this a control cam 84 is driven via a driving belt 82. The belt has the advantage that, because of the overrun of the electric motor on de-energising and the instantaneous arrest of the control cam 84, it becomes stressed in the operation described subsequently. This tension remains after arrest of all parts, so that the control cam 84 is moved momentarily into a following position because of the tension stored in the belt, so that movement of this cam disc by the cam 86 mentioned in the following and the aperture 85 is prevented directly after energisation, even if actuation is only extremely short.

The drive 83 is provided with a ratchet wheel 94, on which a pawl 95 engages. This arrangement can be replaced by some other one-way coupling. The purpose of this arrangement is to prevent return rotation of the driving motor 79 by detensioning of the belt 82 on arrest of the device.

This control cam 84 is provided with an aperture 85, into which a cam 86 is drawn by means of a spring 87. The cam 86 is located upon a pivot lever 88 on which the spring 87 engages. The pivot lever 88 is also connected to an actuating device 89, by which it can be pivoted. For example, this could be the operating knob of the apparatus. The pivot lever 88 serves to actuate a switch with the contacts 90, 91 in the circuit 92 of the driving motor 79. The lever 88 operates on the contact 91 by way of a spring leaf 93.

If the actuating knob 89 is pressed, the cam 86 is lifted out of the aperture 85 and the switch 90, 91 is closed. The motor 79 rotates and at the same time drives the control cam 84. On release of the actuating knob 8-9, the cam slides on the surface of the disc 34 until, after a revolution of the control cam, it is drawn into the aperture 85 by the spring 87. At the same time, the switch 9t), 91 is opened so that the motor comes to rest.

What I claim is:

l. A photocopying device for reproducing a master copy on sheet material, comprising a housing having a base, walls connected to said base and a cover plate connected to said walls, one of said walls being provided with at least one slot adapted to admit a first sheet carrying the master copy and a second sheet having a photosensitive surface adapted to receive an image of said master copy, said housing further having an exit slot for said first sheet adjacent said one slot; illuminating means within said housing comrising a light-transmissive first guide plate and a light source disposed on one side of said guide plate; conveyor means within said housing disposed on the other side of said guide plate, said conveyor means comprising an endless band, at least two axially spaced support rollers for said band and drive means for said support rollers, said band having a forward run and a return run, said forward run being positioned and adapted to press said sheets against said guide plate with said first sheet lying next to said band; a developing section positioned beyond said conveyor means within said housing; sheet-separating means between said conveyor means and said developing section; and guide means for said sheets adjacent said conveyor means; said sheet-separating means being positioned and adapted to deflect said second sheet from said band into said developing section while directing said first sheet between said return run and said guide means; said guide means comprising a second guide plate resiliently bearing on said return run and extending toward said exit slot.

2. A photocopying device according to claim 1 wherein said second guide plate terminates in said exit slot and forms a separate opening therein for the entrance of a third sheet, further comprising transport means adapted to direct said third sheet into said developing section; said developing section comprising a developer container, a pair of squeeze rollers beyond said container and guide elements adapted to pass said second and third sheets into said container and thence between said squeeze rollers, thereby transferring said image from said second sheet onto said third sheet.

3. A photocopying device according to claim 2 wherein said housing is provided with a pair of opposite wall slots extending substantially perpendicularly to said band, said transport means comprising at least one further roller bearing on said second guide plate, said further roller being displaceably journaled in said wall slots, and spring means urging said further roller against said second guide plate.

4. A photocopying device according to claim 2 wherein said forward run lies above said return run, said cover plate defining with said first guide plate a compartment containing said light source, said cover plate having airexhaust apertures above said compartment and, beyond said apertures, a discharge slot for said third sheet, said first guide plate extending to said cover plate between said apertures and said discharge slot.

5. A photocopying device according to claim 1 wherein said sheet-separating means includes a pneumatic device comprising first and second suction means facing each other at a location beyond said forward run for co-operation with said first and second sheets, respectively.

6. A photocopying device according to claim 5 wherein said pneumatic device further comprises air-discharge means positioned beyond said first and second suction means and adapted to blow a stream of air onto the oncoming leading edges of said sheets.

7. A photocopying device according to claim 6 where in said air-discharge means comprises a nozzle of substantially the same width as said sheets whereby said stream of air contacts said leading edges along the entire length thereof.

8. A photocopying device according to claim l, comprising partition means at said one wall, said one wall being provided with another slot separated from said one slot by said partition means and adapted to admit said second sheet concurrently with the admission of said first sheet through said one slot, said band being provided with sheet-gripping means passing through a position of alignment with said partition means on said forward run, said partition means upon such alignment directing said first sheet into engagement by said sheetgripping means while deflecting said second sheet past said sheet-gripping means onto said forward run.

9. A photocopying device according to claim 8 wherein said sheet-gripping means comprises at least one rearwardly pointing flap extending integrally from the outer surface of said band.

10. A photocopying device according to claim 8 wherein said one wall has a portion extending generally parallel to said partition means into substantial alignment with said first guide plate and defining said other slot with said partition means, said portion and said partition means being transparent for enabling observation of said sheets from without.

11. In a photocopying device for transferring an image from a first sheet onto a second sheet, in combination, a housing formed with an entrance for said sheets, a first roller in said housing adjacent said entrance, a second roller in said housing remote from said entrance, endless beit means embracing said rollers, said belt means having a forward run extending from said first roller to said second roller and a return run extending from said second roller to said first roller, a first pressure plate adjacent said forward run adapted to maintain said sheets, upon their simultaneous introduction through said entrance, in face-to-face relationship with each other and in close contact with said band whereby said sheets are conveyed toward said second roller, sheet-separating means at said second roller for directing the outer one of said sheets away from said band, guide means extending around said second roller and forming a path terminating at said sheet-separating means for directing the inner one of said sheets onto said return run, a second pressure plate at said return run adapted to maintain said inner sheet in close contact with said band for entrainment of said inner sheet toward said first roller, discharge means for said inner sheet at said first roller, and partition means at said entrance forming a first channel for said outer sheet and a second channel for said inner sheet, said first channel terminating at said first pressure plate outside the surface of said belt means, said belt means being provided with a flexible, rearwardly pointing surface formation defining a wedge-shaped recess aligned with said second channel upon passing around said first roller whereby the leading edge of said inner sheet can be introduced into said recess while said outer sheet is deflected past said surface formation onto said forward run; said sheet-separating means comprising blower means in the region of said second roller adapted to direct a stream of air onto the oncoming leading edges of said sheets.

12. The combination according to claim 11 wherein said sheet-separating means further comprises first and second suction means facing each other between said forward run and said guide means.

13. The combination according to claim 11 wherein said guide means forms an integral extension of said second pressure plate.

14. The combination according to claim 11 wherein said first pressure plate is transparent, further comprising a light source in said housing adjacent said first pressure plate for illuminating said sheets therethrough.

15. The combination according to claim 14 wherein said rollers have substantially horizontal axes, said first pressure plate and said light source being positioned above the upper run of said belt means.

16. In a photocopying device for transferring an image from a first sheet onto a second sheet, in combination, a housing formed with an entrance for said sheets, a first roller in said housing remote from said entrance, a second roller in said housing remote from said entrance, endless belt means embracing said rollers, said belt means having a forward run extending from said first ,roller to said second roller and return run extending from said second roller to said first roller, a first pressure plate adjacent said forward run adapted to maintain said sheets, upon their simultaneous introduction through said entrance, in face-to-face relationship with each other and in close contact with said band whereby said sheets are conveyed toward said second roller, sheet-separating means at said second roller for directing the outer one of said sheets away from said band, guide means extending around said second roller and forming a path terminating at said sheet-separating means for directing the inner one of said sheets onto said return run, a second pressure plate at said return run adapted to maintain said inner sheet in close contact with said band for entrainment of said inner sheet toward said first roller, discharge means for said inner sheet at said first roller, said discharge means comprising stripper means provided with at least one tongue engaging said belt means in the region of said first roller at a location oifset from the path of said surface formation, and partition means at said entrance forming a first channel for said outer sheet and a second channel for said inner sheet, said first channel terminating at said first pressure plate outside the surface of said belt means, said belt means comprising a plurality of endless, parallel portions transversely separated at least on their surface, said belt means further being provided with a flexible, rearwardly pointing surface formation defining a wedge-shaped recess aligned with said second channel upon passing around said first roller whereby the leading edge of said inner sheet can be introduced into said recess while said outer sheet is deflected past said surface formation onto said forward run, said tongue entering the separation between said portions to a depth greater than that of said recess, said sheet-separating means comprising a rearwardly pointing wedge-shaped formation bearing upon said belt means in the region of said second roller in alignment with said surface formation whereby the latter is urged into firm contact with said inner sheet while said outer sheet is deflected from said belt means, said second pressure plate being provided with an extension forming with said stripper means a third channel for the removal of said inner sheet from said belt means, said third channel being wide enough adjacent said belt means for enabling an erection of said surface formation sufiicient to release said inner sheet.

References Cited by the Examiner UNITED STATES PATENTS 2,194,808 3/40 Pooley 8824 2,317,343 4/43 Betts -75 2,402,929 6/46 Sutherland 95-75 2,431,520 11/47 Streich 9577.5 2,478,850 8/49 Trump 27163 2,574,215 11/51 Kunstadter 9577.5 2,606,478 8/52 Pratt 8824 2,732,778 1/56 Limberger 9577.5 2,878,742 3/59 Trump 9577.5

NORTON ANSHER, Primary Examiner.

D. B. LOWE, E. E. FULLER, ROBERT L. EVANS,

Examiners.

Claims

1. A PHOTOCOPYING DEVICE FOR REPRODUCING A MASTER COPY ON SHEET MATERIAL, COMPRISING A HOUSING HAVING A BASE, WALLS CONNECTED TO SAID BASE AND A COVER PLATE CONNECTED TO SAID WALLS, ONE OF SAID WALLS BEING PROVIDED WITH AT LEAST ONE SLOT ADAPTED TO ADMIT A FIRST SHEET CARRYING THE MASTER COPY AND A SECOND SHEET HAVING A PHOTOSENSITIVE SURFACE ADAPTED TO RECEIVE AN IMAGE OF SAID MASTER COPY, SAID HOUSING FURTHER HAVING AN EXIT SLOT FOR SAID FIRST SHEET ADJACENT SAID ONE SLOT; ILLUMINATING MEANS WITHIN SAID HOUSING COMRISING A LIGHT-TRANSMISSIVE FIRST GUIDE PLATE AND A LIGHT SOURCE DISPOSED ON ONE SIDE OF SAID GUIDE PLATE; CONVEYOR MEANS WITHIN SAID HOUSING DISPOSED ON THE OTHER SIDE OF SAID GUIDE PLATE, SAID CONVEYOR MEANS COMPRISING AN ENDLESS BAND, AT LEAST TWO AXIALLY SPACED SUPPORT ROLLERS FOR SAID BAND AND DRIVE MEANS FOR SAID SUPPORT ROLLERS, SAID BAND HAVING A FORWARD RUN AND A RETURN RUN, SAID FORWARD RUN BEING POSITIONED AND ADAPTED TO PRESS SAID SHEETS AGAINST SAID GUIDE PLATE WITH SAID FIRST SHEET LYING NEXT TO SAID BAND; A DEVELOPING SECTION POSITIONED BEYOND SAID CONVEYOR MEANS WITHIN SAID HOLUSING; SHEET-SEPARATING MEANS BETWEEN SAID CONVEYOR MEANS AND SAID DEVELOPING SECTION; AND GUIDE MEANS FOR SAID SHEETS ADJACENT SAID CONVEYOR MEANS; SAID SHEET-SEPARATING MEANS BEING POSITIONED AND ADAPTED TO DEFLECT SAID SECOND SHEET FROM SAID BAND INTO SAID DEVELOPING SECTION WHILE DIRECTING SAID FIRST SHEET BETWEEN SAID RETURN RUN AND SAID GUIDE MEANS; SAID GUIDE MEANS COMPRISING A SECOND GUIDE PLATE RESILIENTLY BEARING ON SAID RETURN RUN AND EXTENDING TOWARD SIA EXIT SLOT.