US2940584A

US2940584A - Roll film processing apparatus

Info

Publication number: US2940584A
Application number: US583535A
Authority: US
Inventors: Charles J Kunz
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1956-05-08
Filing date: 1956-05-08
Publication date: 1960-06-14
Anticipated expiration: 1977-06-14

Description

June 14, 1960 c. J. KUNZ ROLL FILM PROCESSING APPARATUS 5 Sheets-Sheet 1 Filed May 8, 1956 CHARLES J KU/VZ INVENTOR- BY Mi ATTORNEYS June 14, 1960 c. J. KUNZ ROLL FILM PROCESSING APPARATUS 5 Sheets-Sheet 2 Filed May 8, 1956 CHARLES KU/VZ INVENTOR.

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ATTORNEYS June 14, 1960 c. J. KUNZ ROLL FILM PROCESSING APPARATUS 5 Sheets-Sheet 3 Filed May 8, 1956 Z N R 7 I a m L A m 8 8 m 9 3 3 V. B 2 6 u 0 3 v 6 I! r l 7 (I 5 9 2 f h 8 11%|. 2 4 1 ,4 4 7 3 N 2 f 2 0 a 3 3 J 3 m r -NML}--- A T m n .L A 2 A 6 9\ E2 m 2/ 2 m v, t l/ I A 7 F I- m ATTORNEYS June 14, 1960 c. J. KUNZ 2,940,584

ROLL FILM PROCESSING APPARATUS Filed May 8, 1956 Fig. 5

5 Sheets-Sheet 4 CHARLES J KUNZ INVENTOR.

ATTORNEYS June 14, 1960 c. J. KUNZ 2,940,584

ROLL FILM PROCESSING APPARATUS Filed May 8, 1956 5 Sheets-Sheet 5 CHARLES J KU/VZ INVENTOR.

By diwfi m A TTOR/VE' Y8 United States Patent 2,940,584 ROLL FILM PROCESSING APPARATUS Filed May s, 1956, ser. No. 583,535

Claims. 01. 198- 41) This invention relates to photographic processing apparatus and more particularly to a transport apparatus for conveying separate strips or sheets of photographic material through a series of processing operations. Specifically, it relates to such a transport apparatus employing. magnetic means for attracting and hold the strips or sheets of photographic material to the conveyor and which are adapted to effect the automatic transfer of such strips or sheets from one conveyor to the next.

At the present time, there are two methods which are commonly employed for handling strip or sheet materialsduring their processing. The first involves the use or individual holders or handers to which are fastened one or more strips or sheets and which are subsequently immersed in the individual solutions. The second involves the presplicing of the individual strips to form a continuous length which can then be run through a more or less conventional continuous processing machine. It will be apparent, however, that a system which permits the strips or sheets of photographic material to be fed into the processor at one point and to be delivered completely processed at some subsequent position without the need for hangers or presplicing has definite advantages. Machines of this type now in use employ belts or chains which pass in and out of the several processing solutions conveying the individual strips or sheets in the path thus established. In such arrangements, however, it is ordinarily necessary to fasten by hand the materials to be processed to the belt or chain. Still another system provides apath through the various solutions determined by opposed pairs of driven rollers which drive the photographic materials between them through the several solutions. In another form the material is interposed between a pair of belts which transverse the processing. path. Still other variations of these basic arrangements involve the use of jets of fluid to retain the photographic material in contact with oneor more conveyor belts.

Disadvantages of most of the above prior art machines lie in the complexities involved in such systems. The use of hangers makes necessary the additional steps of loading and unloading and are not readily versatile since they are ordinarily limited to certain size films or papers. These require, too, large tanks and intricate mechanisms for their transportation through the tanks and for their transfer from one to the other. also necessitates the additional step of making the splice between consecutive fihn strips which must subsequently be again separated. Very often these splices are poorly made and their parting causes jams in the machine. The fastening of photographic materials to belts or chains generally involve stoppage of the machine while the fastening is being effected and again after the processing is completed and it often requires the securing of the photographic'strip at both ends to better secure this dur-' ing its transport through the apparatus. Many of the prio'r'a'rt machines' arenot readily adapted for theflhan dling of various size'fihns' and papers; All of the abovedescribed machines are subject to various shortcomings" Presplicing films 2,940,584 iatented June 14, 1960 which render them not" entirely satisfactory for the processing of large volumes of films and/or papers of various sizes.

The apparatus to be described which embodies the present invention overcomes most of the deficiencies of the prior art machines. It is especially adapted for drumtype processing but not necessarily limited thereto. It is simple in its design and substantially foolproof in its operation. It makes necessary a minimum of additional steps and these are essentially of a non-critical nature. It makes possible the use of small quantities of processing solutions and is well suited for the installation in small, restricted areas. It is well adapted not only for the several processing operations which involve fluid treatment but also for the drying and subsequent storage of the film or paper prior to its removal from the machine. Lastly, it requires a minimum of attention by operators.

It is, therefore, an object of the present invention to provide a new and improved photographic processing apparatus.

It is a further object of this invention to provide a new' and improved processing apparatus which is especially adapted for the processing of roll films of various lengths and sizes.

It is a still further object ofthis invention to provide a transport apparatus especially adapted for the conveying of strip or sheet materials which makes use of magnetic means for attaching and holding the materials to the conveyor means.

It is a still further object of this invention to provide a transport apparatus of the character described having a plurality of individual conveyors in which transfer from one conveyor to the next is' accomplished by a shift in magnetic attraction from one conveyor to the next.

It is a still further object of this invention to provide a conveyor of the character described which is as well adapted for carrying the strip or sheet to be processed through a drying section as through the solution treatment tanks.

It is a still further object to provide anapparatus of the class described which facilitates the feeding of individual strips or sheets thereto and their subsequent removal to a storage device or accumulator after processing is completed.

It is finally an object of this invention to provide an apparatus essentially simple in its design and foolproof in operation which requires a minimum of attention by operators.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings, and it will be understood that many changes may be made in the details of construction and arrangement of parts shown and described without departing from the spirit of the invention as-expressed in the accompanying claims.

Fig. l is a diagrammatic view of a portion of a photographic processing apparatus illustrating the means for conveying a photographic material through a plurality of processing solutions.

' Fig. 2 is a diagrammatic view of a further portion of this same processing apparatus illustrating the final wash tank, the drier and the storage section or accumulator.

Fig. 3 is a vertical section through the interior of a processing drum and tank in which it is immersed, illustrating the mechanical arrangement for diminishing the magnetic attraction at the surface of the drum of the permanent magnet within the drum. v

Fig. 4is a vertical section through the d'rurn of Pig. 3.

Fig. 5' is a'vertical section similar to Fig. 3 but illustratinga mcdifi'cationin'which an electromagnet is em ployed, including means for automatically de-energizing the same.

Fig. 6 is a vertical section of the drum seen in Fig. 5. Fig. 7 is an enlarged view in section of a portion of a conveyor drum showing the transverse groove in the surface thereof which cooperates with a magnet to hold other sheet material is ordinarily non-magnetic, it is necessary that a strip of magnetic material 11 be'first secured to the leading edge thereof. Such a strip llrnay comprise a piece of sheet metal or iron Which is clamped' upon the film edge or otherwise secured thereto by adthe strip'of magnetic material will be transferred from the 1 first to the second drum in this transfer region. This shift hesive tape, by stapling, or by any'other means. Such other means may comprise prongs integrally formed upon said magnetic strip. An adhesive strip could also be employed in which grains of a magnetic material are incorporated to serve the same purpose. The strip of magnetic material is removed after the completion of the several processing operations and may be used over again or considered expendable and disposed-of. 'The magnetic strip may also serve as means, or a carrier'therefor, for identifying the specific film to which it is attached.

.The apparatus of Figs. 1 and 2 includes a. feed chute 12 which serves to guide the film strip toward the first of the transfer drums or rollers 13 which in turn conducts the film from the feed means or chute 12 to the first of the series of processing or transport drums 14. The latter drums are adapted to attract and hold to the surface thereof the strip of magnetic material 11 whereby the film strip 10 can be transported by the rotation of the drums 14 through the tanks of processingsolutions 15. Other transfer drums or rollers 13 are employed to effect the transfer of the strips from one conveyor drum 14 to the next." The transfer drums 13 operate in a manner similar to the processing drums 14, employing the force of magnetic attraction to attract and hold the films thereto.

The'specific means employed for this purpose will be hereafter described in detail. The processing or conveyor drum 14 is especially adapted for use in conjunction with a tank 15 of cylindrical form, this configuration making possible the use of relatively smallamounts of solutions,

the advantage of which-from the standpoint of economy will be readily apparent, as well as other advantages, such as improved processing, which result from being able to frequently replace the solutions. V

After leaving the last of .thefiuid treatment tanks, the film 10 is adapted to be drawn between a last transfer drum 16 and a wringer roller 17 which cooperate to remove excess solution before the film enters the drier section 18. Here, too, the conveyor 19, in this instance a belt type, depends upon the force of magnetic attraction to conduct the film between a pair of oppositely disposed air plenums 20. After passing through the drier 18, the individual films are subsequently removed from the belt 19 by a storage device or accumulator 21 which also functions on the principle of magnetic attraction and holds or stores the film strips 10 until these can be manually removed by the operator.

As has been stated, the photographic films or' papers are attracted and held to the conveyor drums or belts by magnetic means and thus transported by the rotation of the drums or travel of the belts. The transfer from one conveyor to the next is accomplished by employing a shift in magnetic attraction from the surface of one drum, orbelt, to the next, transfer drums being generally employed. to effect this shift. Such a transfer drum 13 is used to at-' tract to it the leading edge of the film to which a strip of magnetic material 11 has been secured to withdraw it from the feed slot 12 and to it about the drum to the first It is adapted 4 processing or conveyor drum 14 immersed in the first tank 15 or developing solution. Similar transfer drums 13 are employed to transfer the film from one transport or processing drum 14 to the next. The construction of the several transfer drums may be similar to that of the conveyor or processing drums, each employing magnetic means therein for attracting and holding to the surface thereof the strip of magnetic material secured to the leading edge of the film. 'Such magnetic means may comprise permanent magnets or electromagnets, as will be -de-' sary to produce a shift of magnetic attraction. This is v accomplished by providing that in the region where the drum surfaces approach each other the force of attraction of the magnetic means within the drum transporting the film is less, or becomes less, than the force of attraction of the magnetic means within the second drum, whereby of magnetic attraction may be brought about in several ways.

of attraction at the surface of the first drum by automatically withdrawing the permanent magnet 23 within the drum from the surface thereof in the transfer region 22 to'lessen the attraction at the surface of the drum.

This can be accomplished by an arrangement similar to 7 that illustrated in Figs. 3 and 4. Although Figs. 3 and 4 illustrate such a mechanism in a conveyor or processing drum, the same principle of operation can be utilized in the construction of the transfer drum. However, in the case of the transfer drums 13 and 16 illustrated in the apparatus of Figs. 1 and 2, I prefer to employ a fixed,

permanent magnet 24.mounted in the transfer drum which will provide a force of attraction of sufficiently small value to be overcome by the force of attraction of the processing drum magnet 23 in those regions 25 where the film' is to be transferred from a transfer to a process- 4 ing drum. The force of attraction of these transfer drums, however, is sufficient to attract to them the film from the processing drums in those regions 22 in which the force of magnetic attraction of the processing drums is diminished by the means to be described below.

The cylindrical surface 26 of the transport or con veyor drum 70 of Figs. 3 and 4 is formed of a nonmagnetic material, such as a plastic, there being regularly spaced inserts 27 therein formed of a material of high magnetic permeability and low remanence, these inserts being located immediately above the permanent bar magmaterial 11 at this point on the drum surface. The per-' nets 71 which are mounted within the drum. The purpose of the inserts 27 is to increase the magnetic flux at this point and thereby strengthen the magnetic attraction between the magnet 71 and the strip of magnetic manent magnets 71 are themselves slidably mounted within. guides 28 in the drum which restrict their movement in a radial direction within the drum, by which themagnets may be cyclically withdrawn from and advanced toward the surface of the drum to decrease and increase the attractive force at said drum surface. reciprocating radial movement of the magnets 71 is produced by the coaction between the follower rollers 29 mounted on each magnet 71 and the cams 30 which are fixedly mounted within the drum on the shaft 31 upon '34 cut therein which are adapted to receive and guide the rollers 29 which will roll within the channels as the drum rotates since the cam discs 30 are fixed and the magnet and follower roller assemblies are designed to irritate with the drum. The cam channels 34 are so formed and positioned within the that the magnets In the one it may be done by diminishing the force The cams 30 com-' will be" caused tobe retracted or withdrawn fron'a tlie' drum surfaceas they are rotated past the' tr'ansfer region in which the magnetic strip 11 secured to the filmedge will be transferred to the next adjacent or transfer by the greater magnetic attraction of the latter; An inspection of Figs. 1, 3 and 4 will make this r'eadily ap-' parent. At all other'times when the drum 70'is intended to attract and hold upon its surface the strip'of mag"- netic material. on the the camchannels guide the follower rollers closer to the drum surface to positionthe permanent magnets 71 immediately below this surface to thereby increase the force' of magnetic attraction to a maximum value. Itwill be evidentthat by similarly varying the magnetic attraction of each rocessing drum l4, and especially in the transfer regionsia; may be transported about eachdrum be'tween two transfer r'e"- gions" 01 stations by the rdfafio'n there'of 'em'dtfall'Sfe I fiid from 0116- drum to the next in the"- SO-Cfl-l-ld transfer 16- gions. These transfer regions 22' and 25' are designated in Figs. 1 and 2 by the double headed arrows.

The processing drums 14 are partly immersed in the tanks 15 in which they rotatewhereby the films transported on the drum surface are carried through the solu-' tions to be processed thereby. To prevent a short ro'll of'film 10, having a severe coiling tendency, from winding upon itself and to prevent all film strips from dropping toofar away from the drum 14 to rub on'the tank bottom, since only the leading edge of the film is held to the drum surface, a series of idler rollers 33' is positioned about each processing drum 14', slightly spaced therefrom, which support the trailing edge of each film as it is carried through each tank. It will be obvious that this arrangement permits the use ofa tank 1 5 which follows the contour of thedrum 14 and this together with the displacement of the drum makes pos sible the use of relatively small volumes of processing solutions.

It is preferablethat the processing drums 14 and trans fer drums 13 and 16 be caused to rotate at the same peripheral speed. It will be obvious that it is necessary that a magnet in each of two adjoining drums simultaneously approach the transfer region therebetween in order that the strip of magnetic material at the leading edge of the film being conveyed may be transferred by being simultaneously released by the'first drum and attracted to the second drum surface in this transfer" reg-ion Underthese circumstances, since the transfer drum isordinarily smaller than the processing drum and mounts but a single magnet 24 therein, it will be re-- quired that the larger processing drum have therein a plurality of magnets 23 equal in number to the ratio of the circumference of the processing drum to the circumference of the smaller transfer drum. In the apparatus' of Figs. 1 and 2 the processing drums 14 in the developer, fixer and wash sections are thus provided with four magnets. Figs. 3 and 4 which illustrate the means by which the magnets 71 are advanced and withdrawn relative to a drum surface depict a larger drum having eight magnets. The principle of operation of the drum 70 of Figs. 3 and 4 is, however, applicable to the process'ing drums 14 of Figs. 1 and 2. By' correctly synchronizin'g the rotation of the several drums of the apparatus of Figs. 1 and 2 a magnet 23 within a processing. drum will automatically pass by a transfer region or station between this drum and a" transfer drum each time'the magnet 24 in the transfer drum passes'this same region or'station'.

Each immersed drum 70 rotates upon the fixed shaft 31 upon which the cams 30 are mounted, the shaft ex-' tending across the tank 72 and functioning to mount the drum therein. Scaled bearings 35 are provided between-- the shaft and the drum walls, these being furni shed, too, with conventional packin'gs to preclude'leakage of the processing 's'olution's' from the tank into the interior of the drum; A flanged-sleeve 36- secured" to 6 the drum and fitting" loosely about the -fixecli shah: $11 cit tends through the tank wall. A spur gear 37 keyed to the sleeve-3'6 is employed to drive the, sleeve and thereby rotatethe drum within the processing. tank; Additional by an arrangement similar to that described above in connection with theprocessing drum 70, similar bearings would have'to be provided to permit these drums 13 to be rotated upon fixed shafts, except that, since these are notordinarily immersed in tanks as are the processing drums, the bearingv problem is simplified since the drive for each drum does notextend through a'solution tank. The use, however, of a fixed permanent magnet 24 within the transfer drum 13 as I- have previously described for use in connection with the apparatus of Figs. 1 and 2', further simplifies the construction and mounting of the transfer drums.

It will be noted from an inspection of Figs. 1 and 2 that the transfer drums 13' by rotating in a direction opposite to that of the processing drums 14 permit the films 10 to enter each tank 15 at the same side, passing down into the tank and then up and outat the opposite side.- This allows the tanks tobe arranged linearly, the filmtravcling continuously from one end of the apparatus to the other. Obviously, other arrangements of drums and tanks will suggest themselvesitothose skilled in the photo graphic processing art. Difie'rent size tanks may alsobe employed in combination where a relatively shorter. period ofimmersion in one solution than in the others is found to be adequate. Thus, in the machine illustrated in Figsel and 2 the stop'bath section 39 utilizes a-cor=- respondingly smaller tank and processing drum since a shorter period of immersion in the stop bath will sufiice. Where relatively longer periods of immersion are re quired double tanks with two processing drums may be employed, as in the developer section 40 of the illustrated apparatus. After the stop bath the films ordinarily pass through fixer and wash sections, 41 and 42, respectively, and are then transported bya magnetic belt conveyor 19 through a drier 18 andfinally to a storagesection or accumulator 21- which will be described below. Before doing such, however, I desire firstto describe amodification for obtaining the'shift of magnetic attraction to transfer the films from one drum to the next.

Instead of accomplishing the latter result by physically withdrawing or advancing permanent bar magnets with in the drums, the same result may be had by employing electromagnets and providing means for tie-energizing these in the transfer region to transfer the film from the one drum to the next by this shift in magnetic attraction. A processing drum 43 employing the latter means is illustrated in Figs. 5 and 6. In this arrangement the poles of an electromagnet 44 are embedded in the plastic cylindrical wall 45' of the drum close to the outer surface thereof, the yoke being located within the drum and wound with the customary magnetizing coil 46. The coil is connected through conductors, 47 and 48, to a suitable source of current, not shown. The oneconductor 47 consists of a wire which runs from one end of the magnetizing coil- 46 to a spring finger 49 secured tothe drum near the center thereof, which finger resiliently bears on the copper ring 50 which is mounted on the fixed shaft 51 but insulated therefrom by the insulator ring 52. The copper ring 50 is energized by a wire 53 extending through a drill hole in the shaft 51 from without the drum and tank. This arrangement permits the continuous energization of the one conductor 47 although the drum 43 continues to rotate upon the fixed shaft 51'. Theother conductor 48'is similarly a-wireex'-' tending from the other end of the magnetizing coil to amuse a .wiper 54' mounted upon an insulator disc 55 whichismounted upon a second insulator disc 58 fixed to the the drum about this shaft. In the interval when the wiper makes no contact with the arcuate conductor the electromagnetic coil 46 is no longer energized and the magnetic attraction of the corresponding electromagnet 44 is, accordingly, reduced to zero. This occurs in the transfer region" in which the film is to be transferred from the processing .or conveyor drum to the subsequent transfer drum. Although like the processing drum of Figs. 3 and 4the drum of Figs. 5 and 6 is shown as containing eight magnets, the principle of operation is applicable to any such conveyor irrespective of the number of magnets to be incorporated therein, this number being determined by other considerations as previously discussed in connection with the apparatus of Figs. 1 and 2. Since the drum 43 of Figs. 5 and 6 includes a plurality of electromagnets a separate wire or conductor 48 connects each magnetizing coil 46 with a separate wiper 54, each of the latter being mounted upon the insulated disc or support 55, as seen in Fig. 6, so that each electromagnet may in turn be de-energized as it passes through the transfer.

region. I

It will be readily understood that if any considerable tension is applied to the film along a line tangent to the drum at the point of attachment of the film thereto, there will be a tendency for the strip of magnetic material to slip along the drum surface and to be ultimately withdrawn from the magnetic area. Such an increase of tension might occur particularly in the case of longer films which would impart a greater drag on the film end held to the drum by the strip of magnetic material than would be the case for a shorter film. To overcome this effect a shallow, sharp-edge'dtrough or transverse recess 60 is provided in the drum surface immediately above each magnet. This recess will mate with the strip of magnetic material 11 secured to the film edge, as shown in Fig. 7, and thus prevent slippage along the drum surface as long as the strip 11 is held in the trough or recess 60 by the underlying magnet 71. Moreover, the presence of such a trough will in no Way interfere with the action of the magnets within the drums in transferring the strip from one drum to another, as previously described; A similar result can be obtained by employing mating saw tooth or other patterns on both the drum surface and upon the strip of magnetic material. A transverse recess can be effectively used on either of the processing drums previously described or on the transfer drums.

Although the arrangement of permanent magnets 71,

illustrated in Figs. 3 and 4, and that of electromagnets 44, shown in Figs. 5 and 6, are equally well adapted for use in the processing drums, and although the principle of either may be utilized in the construction of the transfer drums, I prefer, as I have previously indicated, to provide each transfer drum with a single permanent magnet; fixed therein, each such magnet providing a force of attraction which is not as great as the'force of attraction of the magnets in the processing drums when these latter are arranged to provide their maximum force, at the drum surface but greater than the force of attraction of these magnets when the latter are physically withdrawn within the drum or de-energizedin thetransfer region, as the case maybe. The advantage of this arrangement of a fixed magnet within the transfer drum'lies in the simplicity The arcuate conductor57, as

of'the construction of such, since the use of mechanicalmeans for moving the magnet to and from the drum surface or of electrical means for intemittently de-energiz-- ingthe magnet is thus rendered unnecessary.

- Afterpassing through the last tank of the series, that is the wash tank, thefilm end approaches a transfer region for. the transfer of the film from the processing drum to aconveyor 19 which transports the film through a driersection 18. In this transfer region, as in the previous ones, the transfer is effected by a drum. Cooperating with the drum16,'however, is a rubber wringer roller 17 which, is in engagement and rotates therewith. As the passes between this drum and wringer roller,- excess water is removed therefrom :prior to its passinginto the drier section. The drier consists of a pair of of horizontal air plenums 20 from which air is directed through slit orifices upon the fihn 10 passing therebe tween. The film is carried through this section by the magnetic belt conveyor 19 which operates on the same principle previously utilized in the drum conveyors. This belt, which is perforated to permit the passage of air therethrough, passes about pulleys 61 at either end whichdrive the belt in synchronism with the various drums preceding it so that the peripheral speed of the belt is the same as the peripheral speed of the previous drum surfaces.- Magnets 62 are mounted in the belt 19 and spaced apart a distance equal to the circumference of the transfer drum for reasons which are now obvious.- Although the belt magnets 62 may be electromagnets adapted to provide a greater force of attraction than that provided by the transfer drum 16 and designed to be automatically de-energized as they pass the transfer region 63, it is somewhat simpler to form these as permanent magnets. These can be fixed in the belt 19 and selectedto provide a force of attraction at the belt surface which is greater than that provided by the transfer drum 16 at its surface whereby the strip of magnetic material 11 on the film edge passing through the transfer region between the transfer drum 16 and and the drier belt 19 will be withdrawn from the former and attracted and held to the drier belt. As in the case of the drum conveyors, the belt 19 is preferably provided with transverse recesses immediately above each magnet to preclude the strip of magnetic material on the film end slipping along the belt surface and being ultimately withdrawn from the magnetic area.

An idler roller 64 is positioned and spaced slightly from the belt 19 as shown in Fig. 2 and serves a purpose similar to that of the idler rollers 33 located about the processing drums in the several processing tanks. This roller 64 supports the trailing end of the film 10 until such time as the film is transferred from the drier belt 19 to the storage device or accumulator 21. The latter consists of a belt 65 providing a series of spaced permanent magnets 66. This belt 65, passing about pulleys 67 and driven at a speed whereby it travels a distance equal to the spacing of the magnets 66 while the drier belt 19 simultaneously travels a distance equal to that between the magnets 62 along the drier belt, is positioned so that it approaches at one end in close proximity to the drier belt. By correctly synchronizing the operation of the two belts one of the magnets 66 positioned in the accumulator belt 65 will arrive at the transfer region 63 between the two belts whenever one of the magnets 62 of the drier belt 19 arrives at this same region.

"The force of attraction of the magnets 66 of the acses-a 9. indicated, as an alternative the magnets 62' of the drier belt may be electromagnets', designed to be deenergize'd in the transfer region 63, whereby the strip of magnetic material will be readily transferred from the drier to the accumulator belt in the transfer region. Under these circumstances the magnets of the accumulator need not" provide as great a force of attraction as where permanent magnets are utilized in the drier belt. After a number of the-films have been transferred and attached to the storage belt or accumulator, the operator may manually remove these. It is, of course, also possible to employ a storage belt which is formed as a unitary continuous magnet which. will similarly attract to it any film end which arrives at the transfer region 63 because of the superior force of attraction of the storage belt magnet.

Although I have described my invention in connection with photographic processing apparatus, it will be apparent that the transport apparatus: employing magneticattraction' for holding the material to be transported tot-he conveyor and utilizing differences in magnetic attraction between consecutive conveyors for transferring such material from one conveyor to" the next will have application in other than the photographic art. I, therefore, do not wish to be limited to the exact details shown and described as the preferred forms and their application in the photographic art only have been shown by wayof illustration. From the foregoing it will be apparent that I. haveprovidedmeans for obtaining all theobjects and advantages of this-invention.

What I claim and desire to secure by Letters Patent of the United States is:

l. A transport apparatus for sheet material, the leading edge of which is provided with. a strip of magnetic material, comprising a first and second rotatable drum, magnetic means within each drum for attracting and holding to' the surface thereofthe strip of magnetic'material ofsaid sheet material by which the latter is transported. by the rotation of the-drum, said two drums beingpositioned relative to each other whereby their respective surfaces approach in close proximity of each other in a transfer region, means for synchronously rotating said two drums whereby the magnetic'meansof each drum simultaneously moves past the transfer region, means within said first drum for automatically withdrawing the magnetic means therein from the surface thereof as this magnetic means moves past the transfer region thereby diminishing the force of attraction of the magnetic means of the first drum upon the strip of magnetic material of said sheet material while the strip passes through the transfer region whereby this attraction becomes less than the force of attraction of the magnetic means in the second drum upon the strip of magnetic material of said sheet material and the latter is thereby transferred from the surface of the first to the surface of the second drum at said transfer region.

2. A transport apparatus for sheet material according to claim 1 wherein the means within the first drum for automatically withdrawing the magnetic means therein from the surface of the drum comprises a guide for restricting movement of said magnetic means in a radial direction Within the drum to and from the surface thereof, a fixed cam, a follower roller integral with the magnetic means, said cam and follower roller coacting during rotation of the drum to impart a reciprocating radial movement to the magnetic means therein.

3. A transport apparatus for sheet material, the leading edge of which is provided with a strip of magnetic material, comprising a first and second rotatable drum, magnetic means within each drum for attracting and holding to the surface thereof the strip of magnetic material of said sheet material by which the latter is transported by the rotation of the drum, a plurality of idler rollers positioned about the surface of the first drum and slightly spaced therefrom to support the trailing end of the sheet material as the latter is transported by the rotation of said first drum, said two drums being positinned relative toeach other whereby their surfaces approach in close proximity of each other ina' transfer region, means for synchronously rotating said two drums whereby the magnetic means of each drum simultaneously moves past the transfer region, the mag netic means within the first drum comprising an elec'trt magnet, means for automatically deenergizing said elec'-' tromagnet as it moves past the transfer region, whereby the strip of magnetic material of said sheet material is attracted by the magnetic means within the second drum and the said sheet material thereby transferred from the surface of the first to the surface of the second drum atsaidtransfer region.

4'. A transport apparatus for sheet material according" to claim 3 wherein the means for automatically deener gizin'g" said electromagnet as it moves past the transfer region comprises a fixed arc'u'ate conductor and a wiper, said wiper being adapted to revolve with the rotation of said first drum making electrical contact with said arcuate conductor to energize the electromagnet and 'breal'cingthis contact as said electromagnet moves past the transfer region to thereby deenergize the electromag'" netin this region.

5. A transport apparatus for sheet material having a strip of magnetic material at the leading edge thereof, comprising a rotatable drum, magnetic means within the drum for attracting and holding to the surface thereof said strip of magnetic material whereby said sheet material is transported by its leading edge by the rotation of the drum, a plurality of idler rollers positioned about the surface of the drum and slightly spaced therefrom to supporttheitrailing end of the sheet material as the latter is transported by' the rotation of the drum, said drum being" adapted to rotate through a transfer region wherein the'sheet material is adapted to be removed from the drum, means" for diminishing the force of attraction of themagnetic means within the drum as the magnetic means moves past the transfer region, and a magnetic device adapted to'attract said strip of magnetic material of the sheet material as it passes through the transfer region to thereby remove the sheet material from' the surface of said drum.

6. A transport apparatus according to claim 5 wherein said rotatable drum is provided with a transverse recess in the surface .thereof, positioned above the magnetic means within the drum and adapted to receive therein the strip of magnetic material at the leading edge of the sheet material.

7. A transport apparatus for sheet material having a strip of magnetic material at the leading edge thereof, comprising a rotatable drum, a permanent magnet within the drum for attracting and holding to the surface thereof said strip of magnetic material whereby said sheet material is transported by its leading edge by .the rotation of the drum, a plurality of idler rollers positioned about the surface of the drum and slightly spaced therefrom to support the trailing end of the sheet material as the latter is transported by the rotation of the drum, said drum being adapted to rotate through a transfer region wherein the force of attraction of said permanent magnet at the surface of the drum is diminished by the automatic retraction of the magnet from said surface, a guide for restricting movement of said permanent magnet in a radial direction within the drum to and from the surface thereof, a fixed cam, a follower roller integral with the permanent magnet, said cam and follower roller coacting during rotation of the drum to impart a reciprocating radial movement to the permanent magnet therein, and a magnetic device adapted to attract said strip of magnetic material of the sheet material as it passes through the transfer region to thereby remove the sheet material from the surface of said drum.

8. A transport apparatus for sheet material having a strip of magnetic material at the leading edge thereof, comprising a rotatable drum, an electromagnet within the drum for attracting and holding to the surface thereof saidstrip offmagnetic material whereby saidsheet material-is transported by its leading edge .by the rotation of the drum, a plurality of idler rollers positioned about the'surface of the drum and slightly spaced therefrom to'support the trailing end of the sheet material as the latter is transported by the rotation of the drum, said drum being adapted to rotate through a transfer region, meansfor automatically deenergizing said electromagnet as it moves past the transfer region, the latter means including ta fixed arcuate conductor and a wiper, the wiper being adapted to revolve with the rotation of said drum making electrical contact with said arcuate conductor to energize the electromagnet and breaking this contact as said electromagnet moves past the transfer region, and a magnetic device adapted .to attract said strip ofmagnetic material of the sheet material as it passes through the transfer region to thereby remove the sheet materi from the surface of said drum. --9. A transport apparatus for sheet material having a strip of magnetic material at the leading edge thereof, comprising a fixed shaft, a drum mounted upon saidshaft and adapted to rotate thereon, a permanent magnet within the drum for attracting and holding to the surface thereof saidstrip of magnetic material whereby said sheetrmaterial is transported by its leading edge by the rotation of the drum, means for varying the force of attraction of said permanent magnet at the surface of theedrum by automatically moving the magnet to and from the drum surface, said means comprising a guide mountedin said drum, rotatable therewith and adapted to restrict movement of said permanentmagnet in a radial'direction within the drum, a cam fixedly mounted onsaidshaft, and a cam follower integral. with the permanent magnet, said cam and cam follower coacting during rotation of the drum to impart "a reciprocating radial movement to the magnet'therein, a conveyor positioned in close proximity to the surface of said drumat the. point at which the force of attraction of the permanent magnet therein is reduced by withdrawal of the magnet from the drum surface, and magnetic means associated with said conveyor adaptedto attract to the. conveyor said strip of magnetic material of the sheet 12 materialas it passes the point at which-saiddrum and conveyor are in close proximity to thereby transfer the sheet materialafrom the surface of the drum to the con veyor. Y 1 10. -A transport apparatus for sheet material having a strip'of magnetic material at the leading edge thereof, comprising a fixed shaft, a drum mounted upon said shaft and adapted to rotate'thereon, an'electromagnet within; the drum, means for alternately energizing and de-energizing said electromagnet, said electromagnet when energized being adapted to attract and hold to the surface of the drum said strip of magnetic material whereby said sheet material is transported by its leading edge by the rotation of the drum, a plurality of idler rollers'positionedabout the surface of the drum and slightly spaced therefrom to support the trailing end of the sheet material as the latter is transported by the rotation of the drum, said means comprising an arcuate conductor fixedly mounted on said shaft, and a wiper mounted in said drum,

rotatable therewith, and adapted to alternately make and break electrical contact with said arcuate conductor during rotation of the drum, a conveyor positioned incloseproximity to the surface of said drum at the point at which said electromagnet is dc-energized, and magnetic means associated with said conveyor adapted to attract to the conveyor said strip of magnetic material of the sheet material as it passes the point at which said drum and conveyor are in close proximity to thereby transfer the sheet material from the surface of the drum to the:-

conveyor.

References Cited in the file of this patent UNITED STATES PATENTS