US3162436A

US3162436A - Photocopying apparatus

Info

Publication number: US3162436A
Application number: US207265A
Authority: US
Inventors: Halden Joseph Gerald Brocton
Original assignee: Ozalid Co Ltd
Current assignee: Ozalid Co Ltd
Priority date: 1962-07-03
Filing date: 1962-07-03
Publication date: 1964-12-22
Anticipated expiration: 1981-12-22

Description

22, 1964 J. G. B. HALDEN 3,162,436

PHOTOCOPYING APPARATUS Filed July 3, 1962 2 Sheets-Sheet l [il- 55 4106/: for

A ay/r fara/a zrocln k/I 1964 J. G. B. HALDEN 3,

PHOTOCOPYING APPARATUS Filed July 3, 1962 2 Sheets-Sheet 2 M/ Zii% United States Patent Ofiice 3,162,436 Patented Dec. 22, 1964 3,162,436 PHOTOCOPYING APPARATUS Joseph Gerald Brocton Halden, Laughton, England, assignor to Ozalid Company Limited, Loughton, England, a company of Great Britain Filed July 3, 1962, Ser. No. 207,265 15 Claims. (til. 2'71--64) This invention relates to photocopying machines and in particular to means in such machines for separating original sheets from prints on sensitised sheet material. The invention may for example, be applied to diazotype copying machines.

The invention provides a photocopying machine of the kind comprising a printing section in which a sheet of sensitised material superposed on an original is exposed to actinic light, a developing section for the exposed sensitised material, a feed path from the printing section to the developing section and separating means in the feed path to separate the original from the sensitised sheet so that the sensitised sheet may continue along the feed path and the original may be delivered outside the machine, in which machine the separating means comprises a first vacuum means on the original side of the feed path to which the original is attracted and second vacuum means on the sensitised-sheet side of the feed path to which the sensitised sheet is attracted, one of the vacuum means being a hollow rotatable roller perforate around its circumference and having stationary sealing means within the roller isolating a hollow section bounded on the outside by the part of the perforate circumference for the time being opposite the said path and means for connecting said hollow section to a source of vacuum.

Preferably there is a detection device in the feed path between the printing section and the separating means which device controls the application of vacuum to the said roller section and is effective, on detecting the passage of a superposed original and sensitised sheet to cause evacuation of said roller section.

The vacuum roller may be on the original side of the feed path and in one construction the vacuum means I on the sensitised sheet side of the feed path is a vacuum plate and at least a part of the vacuum plate is directly opposite to the vacuum roller. Alternatively both the vacuum means maybe vacuum rollers.

The feed path may be defined by a set or sets of endless conveyor belts.

The vacuum roller or each roller, may comprise a stationary hollow shaft extending the full width of the roller which shaft is connected to a vacuum reservoir, a row of perforated rotatable cylinders co-axially around the shaft, a stationary sealing member between each cylinder and the shaft which sealing member extends around part of the circumference of the cylinder and seals and perforations around the said part of the cylinder and vacuum connections between the shaft and the open perforations in the cylinder, the shaft also having means for connection to a source of vacuum. The detection device may operate a solenoid to open and close a valve between the shaft and the vacuum reservoir or other source.

The invention further provides a photocopying apparatus as described above and including, between the paths ofthe original and the sensitised material as they leave the separating means, a first rotating roller adjacent the original path and a second rotating roller adjacent the sensitive sheet pathwhich rollers have their axes parallel to that of the vacuum roller and rotate in opposite directions such that the surface of each roller which faces towards the separating means, moves towards the adjacent path.

The first and second rotating rollers may rotate with a peripheral speed much higher than the linear speed of the original and the sensitised material along their respective paths, and preferably the first rotating roller is provided with a surface having a low coeflicient of friction and the second rotating roller has a surface having a high coefiicient of friction.

The two rotating rollers may each be composed of a plurality of short rollers axiallyspaced apart from one another and the rotating rollers may be soarranged that their short rollers intercalate.

Due to its speed of rotation the low friction roller will turn down without folding corners or torn portions of the leading edge of the sheet as it is ejected from the separator.

Further, if the sensitive sheet is of such a material as not to be held closely adjacent to its vacuum roller the leading edge of such a sheet due to its natural line of travel will slide along the low friction surface of the first rotating roller even though it is rotating in the opposite direction to that of the said sheet travel until it is acted upon by the second rotating roller which because of its high friction surface will deflect the leading edge of this sheet back towards its vacuum roller, the combined effects of the vacuum roller and of the rotating roller ensuring that the sheet is conveyed to the developing section of the machine.

Continuous surfaced rollers may be used in place of intercalated rollers in which case they are disposed so that their diameters overlap to a substantial extent as received 'along the feed path and the gap between them is extremely small. In this case the first or low friction roller having its axis nearer to the separating print than that of the second or high friction roller will permit an overlap of about one half a diameter. By this means itcan be ensured that the leading edge of a sheet of material sliding over the rotating surface of the low friction roller towards the high friction roller must'meet the surface of the high friction roller edge on and thus be deflected in the direction required.

Guide plates and feed rollers may be provided to lead the separated sensitive sheet from the separating mean to the developing section.

It will be appreciated that originals to be copied being on transparent or translucent material, usually flexible in nature and in consequence the suction obtaining in the vacuum roller will be adequate in all cases to hold the original to its periphery and thus to direct it as required to its desired location of the machine.

Further, in cases where the print material is of a relatively light weight and of a flexible nature this will also be held to the periphery of its vacuum roller and in such cases the mechanical deflecting rollers will not be required to function.

However, where stiff material is used as the print material this may be only partially affected or maybe deflected only to an inadequate degree by its vacuum roller and in consequence will tend to continue in its natural line of travel which, without theemployment of the mechanical separating rollers, would result in a misfeeding with all its attendant difficulties and disadvantages.

in such a case where stiff material is employed for the print it will, as in the case previously referred to, tend upon emerging from the print section of the machine to continue in its natural line of travel unaifected or only inadequately aifected by its vacuum roller.

The leading edge of such a print will therefore come into contact with the low fraction roller and slide over its surface until it is acted upon by the high friction roller which will deflect it back towards and under the influence of its vacuum roller.

The vacuum roller will then direct the print to the guide plates and feed rollers which will lead it to the developer section of the machine.

Two specific examples of machines according to the invention will now be described with reference to the acompanying drawings in which:

" FIGURE 1 is an end view of a print separating device for a diazotype photocopying machine,

FIGURE 2 is a view, partly in section, of the vacuum roller of FIGURE 1 and FIGURE 3 illustrates diagrammatically a second form of print separating device for a diazotype photocopying machine, said device being located, as is conventional, between the printing section of the machine and the developing section thereof.

Referring now to the machine shown in FIGURES 1 and 2 of the drawings the printing cylinder of the machine is shown at 1 with its print traversing belts 2 passing around guide roller 3 and over the conventional suction tank 4 to the developing section (not shown) of the is in juxtaposition to the run of the print conveyor belts 2 extending from the printing cylinder 1 to the developer section of the machine. It will therefore be seen that an original and a light sensitive sheet after passing around the printing cylinder 1 will travel in superposed relationship between two sets of endless belts 2 and 5, the original lying adjacent to the belts 5 of the original delivery system and the exposed light sensitive sheet adjacent to the print conveyor belts 2.

The run of the belts 5 of the original delivery system forming the base of the triangle extends at right angles to, and away from, the print conveyor belts 2 and serves to deliver the original outside the machine, either at the front thereof or to a further set of conveyor belts 9 which 'deliverthe original to the rear of the machine.

A pair of trip contacts 10 and 11 are located immediately preceding the vacuum roller 6 and disposed one on either side of the juxtaposed belts 5 and 2 of the original delivery system and the print conveyor system. The trip contacts control a solenoid operated vacuum valve (not shown) and when the contacts are interrupted by the passage of an original and a sensitive sheet the valve is operated to place the roller under vacuum.

Disposed in rear of the print conveyor belts 2 and at a position substantially opposite the vacuum roller 6 is a vacuum plate 12 and following this is the conventional section tank 4. The vacuum plate 12 is connected to a source of vacuum by connection 13, and is arranged to be evacuated when .a predetermined degree of vacuum is I obtained in the vacuum roller 6. This can be accomplished by any usual or conventional means e.g. a pressure sensitive vacuum switch.

Referring now more particularly to FIGURE 2 the vacuum roller 6 is built up from relatively narrow width units indicated by the reference numerals 14 and 15 and comprises a stationary hollow shaft member 16 extending for the full width of the roller, the hollow shaft being connected'to a vacuum reservoir (not shown) by any appropriate means, the vacuum solenoid valve being interposed in the connection. Surrounding the central hollow shaft 16 are a plurality of roller cores 17 and 18 each core comprising aunit, the core units also remaining static during operation of the roller.

-=the core units 17, 18' threaded thereon.

Circular sealing members shown at 21, 22 and 23 are provided between the rotatable end discs and their adjacent core units.

The roller sections 14 and 15 proper comprise roller sleeves 24 and 25 extending between end discs 19, 26, 27 with narrow intervening air gaps shown at 28 and 29 between the sleeve members 24 and 25 and the roller core units 17 and 18, insert segments 30 and 31 being provided around the peripheries of the core units 17 and 18. The gaps 28 and 29 communicate with the interior of the hollow shaft 16 by a channel 38 (FIGURE 1). The roller sleeves 24 and 25 are formed with lands 32 and falls 33, the conveyor bands 5 riding in and being located by the falls 33 which are so dimensioned as to accommodate the conveyor bands and provide, when the conveyor bands are so located, a substantially smooth exterior surface to the vacuum roller.

The lands 32 on the roller sleeves 24 and 25 are perforated at 34 and the falls 33 slotted at 35 to enable vacuum built up in the roller to act substantially uniformly over the surface thereof. To define an arc of the roller periphery over which the vacuum will act, sealing members, 36 FIGURE 1 which may comprise anti-friction plastic material may be provided, the said sealing members 36 being segmental members closing the beforemcntioned air gap 28 or 2d as the case may be around a predetermined are. adapted to be sprung into position and thus may be self adjusting.

Referring now to the machine shown in FIGURE 3 a print vacuum roller 51 is located adjacent to and above a printing cylinder 52 and rotates in a direction to feed a print 53 from the said printing cylinder 52 towards the developing section of the machine so that as the leading edges of the superposed original 54 and print 53 reach the vacuum roller 51, the print 53 being disposed uppermost will come under the influence of the vacuum roller 51 and will, together with the original 54 be directed upwardly away from the printing cylinder 52 between the print vacuum roller 51 and an original vacuum roller 55 which is disposed in front of the print vacuum roller 51.

The arcs of the vacuum rollers over which vacuum is applied is controlled as in the machine shown in FIG- URES 1 and 2 and vacuum may be applied by means of two stage fans generating relatively high negative pressures. Up to approximately 13.5" Hg negative pressure is obtained with 10" diameter fans and this is increased to 22" Hg with 16" diameter fans. Alternatively and where a higher. degree of vacuum is required for particular applications the fans may be replaced by an exhauster.

Stripping fingers 62 in contact with the printing cylinder 52 ensure that the original 54 is detached from the cylinder 52 and guided towards its vacuum roller 51, but these are only necessary with the heaviest weights of material;

with lighter weights the air feed into the

vacuum rollers

51 and 55 is of such high velocity and its path so confined by'the disposition of the vacuumrollers that an air knife effect is created sufficient to ensure that all but the heaviest materials are blown off the cylinder 52.

' The original 54 will then come under the influence of its vacuum roller 55 and by virtue of its flexible nature will be held against its periphery over the arc of the roller through which vacuum is applied. The original vacuum roller 55 rotates in a direction to feed the original 54 along a path 64 to the required location of the machine e.g. to a stacking tray (not shown) disposed externally of the machine and thus tends to separate the original 54 from the print 53.

g If the print 53 is on a stiff material, as it emerges from the nip formed between the two vacuum rollers '51 and 55 it will tend, at least to some extent, to continue in its natural line of travel which may only be slightly modified by the vacuum of its roller 51.

- If continued travel were permitted this would result The sealing members 36 may be in mis-feeding and it is a feature of this invention to avoid mis-feeding by means of mechanical deflector rollers.

, A first rotating roller 56 which has a low friction surface or low friction segments thereon is located adjacent to the periphery of the original vacuum roller 55 and rotates in a direction opposite to that of the said vacuum roller 55 (i.e. the two

rollers

55 and 56 rotate in opposite directions about their axes but adjacent roller surfaces at the point of contact between the rollers have the same angular movement) and at a speed of two and a half times that of the linear speed of the sheets passing through the machine. s The original 54 being held to its vacuum roller periphery 55 will pass under the roller 56 which may assist in feeding it to the required location while the print 53 (which is being fed forwardly away from both the original vacuum roller 55 and its own vacuum roller 51) will now come into contact with the periphery of the roller 56. The continued feed of the print 53 will cause its leading edge to slide up the surface of roller 56 until it meets a second roller 57 which is equipped with a high friction surface or high friction rubber segments.

Roller57 is rotating in a direction opposite to that of g the low friction roller 56 and at a speed approximately 3 times the linear speed of the print 53.

Immediately the leading edge of the print 53 comes into contact with the second roller 57 it is deflected quickly rearw-ardly towards and comes under the influence of vacuum roller 51 and is fed between appropriately.

spaced guide plates 58 and 59 which lead to the developer section of the machine.

The

rollers

56 and 57 each comprise a plurality of short rollers spaced apart from one another and the short rollers of the roller 56 intercalate with the short rollers of the roller 57.

Contact rollers

60 and 61 are provided at the entry of the channel formed between the spaced guide plates 58 and 59 to feed the print 53 to the developer section of the machine.

It Will be appreciated that once the leading edge of the print 53 comes under the influence of its vacuum roller 51 the remainder of the print is traversed through the separator section fully controlled by the vacuum.

I claim:

1. A photocopying machine of the kind comprising a printing section in which a sheet of sensitised material superposed on an original is exposed to actinic light, a developing section for the exposed sensitised material, a feed path from the printing section to the developing section, separating means in the feed path to separate the original from the sensitised sheet so that the sensitised sheet may continue along the feed path and the original may be delivered outside the machine, which separating means comprises a first vacuum device on the original side of the feed path to which the original is attracted and a second vacuum device on the sensitised-sheet side of the feed path to which the sensitised sheet is attracted, one of the vacuum devices being a hollow rotatable roller perforate around its circumference and having stationary sealing means within the roller isolating a hollow section bounded on the outside by the part of the perforate circumference opposite to said path and means for connecting said hollow section to a source of vacuum and a detection device in the feed path between the printing section and the separating means which device controls the application of vacuum to the said roller section and is effective, on detecting the passage of a superposed original and sheet of light sensitised material, to cause evacuation of said roller section.

2. A machine as claimed in claim 1 in which the vacuum roller is on the original side of the feed path.

3. A machine as claimed in claim 1 in which the vacuum roller is on the original side and the vacuum device on the sensitised sheet side of the feed path is a vacuum plate, at least a part of the vacuum plate being directly opposite to the vacuum roller.

4. A machine as claimed in claim 1 in which both vacuum devices are vacuum rollers as aforesaid.

5. A machine as claimed in claim 1 comprising a first set of conveyor belts adapted to transport a superposed original and sensitised sheet through the printing section andto transport the exposed sensitised sheet to the developer section, a second set of conveyor belts adapted to transport the original, after it has passed the printing section, for delivery outside the machine, a vacuum roller and a vacuum plate, a detection device for actuating the vacuum roller and plate when the original and sensitised sheet pass the detection device in their path from the printing section towards the developing section, said vacuum roller when actuated operating to attract and hold the said original against a part of its surface or against conveyor belts traversing its surface and to change the direction of travel of the said original to direct it towards the outlet of the machine and the vacuum plate being effective to attract the exposed sensitised sheet so that it continues in its original line of travel towards the said developing section.

6. A machine as claimed in claim 1 wherein a perforated suction tank is arranged adjacent the second vacuum device at a position at which it can act on the exposed light sensitised material after the leading edge of the original has been separated therefrom by the first vacuum device.

7. A machine as claimed in claim 1 in which the detection device comprises electrical trip contacts operable by the superposed original and sensitised sheet as they are moving from the printing section of the machine towards the developing section thereof.

8. A machine as claimed in claim 1 wherein vacuum is applied first to the first vacuum device and when a predetermined degree of vacuum is obtained therein the vacuum is applied to the second vacuum device.

9. A machine as claimed in claim 1 in which the vacuum roller comprises a stationary hollow shaft extending the full width of the roller, a row of perforated rotatable cylinders co-axially around the shaft, a stationary sealing member between each cylinder and the shaft which sealing member extends around part of the circumference of the cylinder and seals the perforations around the said part of the cylinder and vacuum connections between the shaft and the open perforations in the cylinder, the shaft also having means for connections to a source of vacuum.

10. A photocopying machine of the kind comprising a printing section in which a sheet of sensitised material superposed on an original is exposed to actinic light, a developing section for the exposed sensitised material, a feed path from the printing section to the developing section, separating means in the feed path to separate the original from the sensitised sheet so that the sensitised sheet may continue along the feed path and the original may be delivered outside the machine, which separating means comprises a first vacuum device on the origina side of the feed path to which the original is attracted and a second vacuum device on the sensitised-sheet side of the feed path to which the sensitised sheet is attracted, one of the vacuum devices being a hollow rotatable roller perforate around its circumference and having stationary sealing means Within the roller isolating a hollow section bounded on the outside by the part of the perforate circumference opposite to said path and means for connecting said hollow section to a source of vacuum, a detection device in the feed path between the printing section and the separating means which device controls the application of vacuum to the said roller section and is effective, on detecting the passage of a superposed original and sheet of light sensitised material, to cause evacuation of said roller section and including, between the paths of the original and the sensitive material as they leave the separating means, a first rotating roller adjacent the original path and a second rotating roller adjacent the sensitive material path which rollers have their axes parallel to-that of the vacuum roller and rotate in opposite directions such that the surface of each roller which faces towards the separating means, moves towards the adjacent path. a

11. A machine as claimed in claim 10 in which the first and second rotating rollers rotate with a peripheral speed much higher than the linear speed of the original and the sensitised material along their respective paths.

12. A machine as claimed in claim 10 in which the first rotating roller is provided with a surface having a low coetficient of friction and the second rotating roller has a surface having a high coefiicient of friction.

13. A machine as claimed in claim 10 in which the two rotating rollers are each composed of a plurality of short rollers axially spaced apart from one another and the rotating rollers are so arranged that the short rollers of one rotating roller interfit with the short rollers of the other rotating roller.

14. A machine as claimed in claim 10 wherein guide plates and feed rollers are provided to lead the sensitised sheet from theseparating means to the developing section. a

.15. Aphotocopying machine astclaimed in claim 10 and comprising a first suction roller adapted to attract towards a portion of its periphery a sheet of light sensi'- .tised material as it "is emerging from the printing section :of. the machine superposed on an original, asecond vacuum roller adapted to attract towards a portion of its periphery the original thereby to tend to separate the light sensitised material and the original, a first rotating roller having a low friction surface and adjacent to the periphery of the vacuum roller for the original and adapted to guide-the said original towards a location out- "side the machine, and a second rotating roller having a high friction surface and adjacent to the first rotating roller and adapted to deflect for delivery to the developer section of the machinethe light sensitised material if, due to its weight and/ or stiffness, it has not been held to the periphery of its vacuurnroller.

References (Zitedjin the file of this patent

Claims

1. A PHOTOCOPYING MACHINE OF THE KIND COMPRISING A PRINTING SECTION IN WHICH A SHEET OF SENSITISED MATERIAL SUPERPOSED ON AN ORIGINAL IS EXPOSED TO ACTINIC LIGHT, A DEVELOPING SECTION FOR THE EXPOSED SENSITISED MATERIAL, A FEED PATH FROM THE PRINTING SECTION TO THE DEVELOPING SECTION, SEPARATING MEANS IN THE FEED PATH TO SEPARATE THE ORIGINAL FROM THE SENSITISED SHEET SO THAT THE SENSITISED SHEET MAY CONTINUE ALONG THE FEED PATH AND THE ORIGINAL MAY BE DELIVERED OUTSIDE THE MACHINE, WHICH SEPARATING MEANS COMPRISES A FIRST VACUUM DEVICE ON THE "ORIGINAL" SIDE OF THE FEED PATH TO WHICH THE ORIGINAL IS ATTRACTED AND A SECOND VACUUM DEVICE ON THE "SENSITISED-SHEET" SIDE OF THE FEED PATH TO WHICH THE SENSITISED SHEET IS ATTRACTED, ONE OF THE VACUUM DEVICES BEING A HOLLOW ROTATABLE ROLLER PERFORATE AROUND ITS CIRCUMFERENCE AND HAVING STATIONARY SEALING MEANS WITHIN THE ROLLER ISOLATING A HOLLOW SECTION BOUNDED ON THE OUTSIDE BY THE PART OF THE PERFORATE CIRCUMFERENCE OPPOSITE TO SAID PATH AND MEANS FOR CONNECTING SAID HOLLOW SECTION TO A SOURCE OF VACUUM AND A DETECTION DEVICE IN THE FEED PATH BETWEEN THE PRINTING SECTION AND THE SEPARATING MEANS WHICH DEVICE CONTROLS THE APPLICATION OF VACUUM TO THE SAID ROLLER SECTION AND IS EFFECTIVE, ON DETECTING THE PASSAGE OF A SUPERPOSED ORIGINAL AND SHEET OF LIGHT SENSITISED MATERIAL, TO CAUSE EVACUATION OF SAID ROLLER SECTION.