US3846808A

US3846808A - Processor assembly

Info

Publication number: US3846808A
Application number: US00429898A
Authority: US
Inventors: J Whall
Original assignee: Polaroid Corp
Current assignee: Polaroid Corp
Priority date: 1974-01-02
Filing date: 1974-01-02
Publication date: 1974-11-05
Anticipated expiration: 1991-11-05

Abstract

A processor assembly adapted for use with selfdeveloping cameras and including a pair of rollers each having a tubular roller shell and a flexible shaft extending through the shell. One of the roller shells may be journaled on the shaft on which it is supported whereas the other of the roller shells may be driven by its supporting shaft through torque limiting couplers corresponding in axial position to the axial position of the bearings in the other roller shell. In a preferred embodiment, a bracket supports the roller shells in a coplanar relationship, establishes a working nip between the roller shells, and retains the shafts in a stressed condition to provide a minimum preload bias between the rollers. Pregap collars may be secured at opposite ends of one of the rollers to provide a minimum pregap between the pair of rollers at the working nip.

Description

United States Patent 1191 Whall PROCESSOR ASSEMBLY [75] Inventor: James M. Whall, Lexington, Mass.

[73] Assignee: Polaroid Corporation, Cambridge,

Mass.

[22] Filed; Jan. 2, 1974 [21] Appl. No.: 429,898

[52] US. Cl. 354/86, 100/162 B, 226/190,

354/304 [51] Int. Cl. G03b 17/50 [58] Field of Search 354/86, 84, 304; 100/162 B; 226/190, 194

56 '1 References Cited UNITED STATES PATENTS 2,740,340 4/1956 Bing et a1 354/304 X 3,779,144 12/1973 Paglia 354/304 R2692] 6/1970 Erlichman 354/304 X [111 3,846,808 1451 'Nov. 5, 1974 Primary Examiner-Richard L. Moses Attorney, Agent, or Firm-Alfred E. Corrigan [57] 1 ABSTRACT A processor assembly adapted for use with selfdeveloping cameras and including a pair of rollers each having a tubular roller shell and a flexible shaft extending through the shell. One of the roller shells may be journaled on the shaft on which it is supported whereas the other of the roller shells may be driven by its supporting shaft through torque limiting couplers corresponding in axial position to the axial position of the bearings in the other roller shell, In a preferred embodiment, a bracket supports the roller shells in a coplanar relationship, establishes a working nip between the roller shells, and retains the shafts in a stressed condition to provide a minimum preload bias between the rollers. Pregap collars may be secured at opposite ends of one of the rollers to provide a minimum pregap between the pair of rollers at the working.

23 Claims, 6 Drawing Figures 1 PROCESSOR ASSEMBLY BACKGROUND OF THE INVENTION This invention relates to improvements in selfdeveloping photographic cameras and more particularly, it concerns an improved spreader assembly for the film developing or processing apparatus of such cameras.

Self-developing cameras which employ a film unit having a self-contained supply of developing or. processing fluid are well known in the photographic art. In the operation of such cameras, exposure of a light sensitive emulsion carried by the film unit is followed by the spread of the processing fluid over the emulsion to effect a diffusion transfer formation of a visible positive image. The release of the processing fluid and the spreading thereof uniformly over the exposed emulsion has been most conventionally accomplished in the past by pulling the film unit between a pair of opposed pressure surfaces, such as rollers, which function both to rupture the self-contained supplyor pod of processing fluid and spread the fluid uniformly over the emulsion layer in squeegee fashion by further withdrawal of the film unit through the opposed pressure surfaces.

Exemplary disclosures of relatively recent developments in such cameras and film units are found in US. Pat. No. 3,415,644 entitled Novel Photographic Products And Processes, US. Pat. No. 3,766,842 entitled Photographic Film Processing Apparatus and in U.S. Pat. No, 3,714,879 entitled Reflex Camera, all of which are assigned to the assignee of the present invention. With the film units described in the first two of these US. patents, when passed between a rolltype processing station, a pod-like container is ruptured and a processing fluid including an opacifying agent is spread as a layer to provide a background for the photosensitive transfer image evolved during development. Because the opacifying agent serves as a light shield during the diffusion transfer development process, it is important that the spread of the fluid be properly regulated to ensure a smooth and continuous spreading of the fluid over the photosensitive layer of the film unit. Such film units are processed in a highly effective manner by the automated single lens reflex camera disclosed, for example, in the aforementioned U.S. Pat. No. 3,714,879, and which incorporates motor driven processing rollers to effect the processing fluid dispensing and spreading functions.

The functional or operational requirements of the spreader assembly in such cameras are manifold. For example, it is important that the film unit engaging surfaces on the spreader assembly be positioned and remain positioned in precise parallelism with respect to each other. In addition, it is important that the opposed spreader surfaces be biased toward one another and thus against opposed surfaces of the film unit being processed under a preestablished precise biasing force to achieve the complete spreading of the processing fluid over the surface of the exposed emulsion without imposing excess loading on the driving components of the rollers. While such functional requirements have been effectively fulfilled by prior commercial embodiments of the camera system exemplified by the aforementioned US. patents, there is need for improvement from the standpoint of reduction of manufacturing and assembly costs while retaining these functional requirements.

In addition, with cameras of the type disclosed in the aforementioned US. Pat. No. 3,714,879, there may be a tendency by some unknowing photographers to pull the film unit manually as it is being power driven through the processing spreader rollers and discharged from the camera, or for the film advancing mechanism of the camera to advance more than one film unit at a time into the bite of the rollers, thereby creating a jam at the biteof the rollers. Although the damage to the film units which might result is relatively inconsequential, of more serious concern is the potential damage to the driving components of the rollers.

SUMMARY OF THE PRESENT INVENTION In accordance with the present invention, an improved spreader assembly for self-developing photographic cameras of the type referred to is provided by supporting a pair of tubular roller shells at axially spaced bearing points about flexed resilient shafts to bias the roller shells one against the other. The roller shells are provided with precision formed external cylindrical surfaces and one of which may receive at opposite ends a pair of annular collars to effecta preestablished radial gap at the nip of the roller shell pair. The axially spaced bearing points of the roller shells on the flexed shaft are spaced inwardly from the ends of the rollers with the ends of the shafts projecting also from the ends of the roller shells to a supporting bracket so that opposite ends of the flexed shafts are spaced by a distance less than the radial distance between the axes of the roller shells. One of the roller shells may be journaled on the shaft on which it is supported whereas the other of the rollers may be driven by its supporting shaft through torque limiting couplers corresponding in axial position to the axial position of the bearings in the other roller shell. In an alternative embodiment of the invention, the rollers are mounted on separate supports such that they may be spaced V apart a distance sufficient to permit a film cassette to be passed therebetween and into the cameras film chamber.

Among the objects of the present invention are: the provision of an improved processing apparatus for selfdeveloping photographic cameras; the provision of such a processing apparatus which is adaptable to an automated power-"driven film unit processing operation; the provision of such an improved processing apparatus in which the number of component parts is minimized, which is compact and which is light in weight; the provision of such an improved processing apparatus which is easily and thus economically assembled duringmanufacture; the provision of such an improved processing apparatus which is capable of being manually mishandled without damage to other components of the camera in which it is used; and the provision of such an improved processing apparatus having a pair of rollers which are movable into a position in which a film cassette may be passed therebetween during film loading of the camera.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description to follow taken in conjunction with the accompanying drawings in which like reference numerals designate like parts.

BRIEF DESCRIPTION OF THE DRAWINGS with portions broken away .to reveal internal structure;

FIG. 3 is a cross-section taken on line 33 of FIG.

FIG. 6 in view similar to FIG. showing the processing apparatus of'FlG. 5 is an unloaded condition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. I of the drawings, an embodiment of the improved processing apparatus of this invention is illustrated in a fully automatic single-lens reflex camera generally designated by the referencenumeral 10. Although described in detail in the above-mentioned U.S. Pat'No. 3,714,879, it will suffice for purposes of a clear understanding of the present invention to note that the camera 10 basically includes a rectangular base 12, a roller housing section 13 pivotally coupled to base 12 at 15, a rear wall 14 connected to the rectangular base by a hinge l6, and a forward wall 18 connected to an exposure control housing 20 by a hinge 22. A collapsible optical entrance assembly 23 having a top cap 24 is supported above the forward wall 18. The exposure control housing 20 supports an objective lens assembly 26, a photocell entrance assembly 28, and a manually actuable release button 30 which serves to commence an automatic photographic cycle. The rear wall 14 is supported in an erected position by linkages 32 and the interior exposure chamber of the camera housing is established by a flexible, opaque bellows 34.

The base 12 is configured to receive a disposable film retaining cassette structure, a portion of which is shown in FIG. I and designated by the reference numeral 36 when section 13 is pivoted clockwise through an angle FIG, 4 is a cross-section taken on line 4-4 of FIG.

FIG. 5 is a front elevation of an alternative embodiment of the. invention with portions broken-away; and

of approximately 90. The cassette 36 retains a stacked array of discrete film units (not shown) the uppermost of which is disposedbehind an egress opening or slot 38. The film units, as described in detail in the previously mentioned U.S. Pat. No. 3,415,644, include all the materialsnecessary to produce positive photographic prints and are provided with a rupturable container or pod of processing fluid secured to a photosensitive composite in a position suchthat the pod is located near the slot 38. The developing process involves the formation of transverse image-forming substances in an exposed photosensitive element of the unit accompanied by their diffusion in a manner forming a visible positive image, the photosensitive components being protected from light during processing by an opacifying agent spread as a layer to provide an opaque background for the photosensitive transfer image evolved during development.

During the automated photographic cycle of the camera 10, a motor (not shown) supported on the base 12 is operated at the appropriate time to drive a gear 4 I train, an end gear of which is designated 40 in FIG. 1. This power driven arrangement is operatively connected to the processing apparatus of this invention which is generally designated in the drawings by the reference numeral 42. As shown, the processing apparatus or processor 42 is disposed adjacent to the eassette egress opening 38 and mounted within a roller housing section 13. As in prior designs, the processor 42 includes as basic operating components, a pair of

opposed rollers

44 and 46, at least one of which, the

roller 44 in this instance, is arranged to be rotatably driven directly by the camera drivemotor (not shown) by meshing engagement of the end gear 40 of the camera drive train with a roller drive gear 48. Also as shown generally in FIG. 1 and more particularly in FIG. 2, the

rollers

44 and 46 are supported within the housing 13 on a U-shaped support bracket 50 to be described more fully below. The U-shaped support bracket 50 is secured to housing 13 by any suitable means such as adhesive bonding, interlocking tabs, screws or the like capable of ensuring retention of the processor 42 within the housing 13 adjacent to the egress opening 38 of the film cassette structure 36.

The operating function of the processor 42 is the same as that described in the aforementioned U.S. Pat. No. 3,766,842; that is, to receive a film unit advanced through the slot 38 between the

rollers

44 and 46 after exposure, rupture a processing fluid pod'at the leading edge of the film unit, and advance the unit forwardly out of the camera while simultaneously spreading the cordance with the present invention, however, the processor 42 and the

rollers

44 and 46 are provided by an improved structural organization shown most clearly in FIGS. 2-4 of the drawings. p

As shown in FIG. 2, the upper roller 44 is an assembly of a tubular roller shell 52 having counterbores 54 at opposite ends, a flexible'shaft 56 and a pair of resilient couplers each of annular configuration to support the shell 52 on the shaft 56 at points spaced along the axis of the roller 44 and established by the bottom of the counterbores 54. The drive gear 48 is fixed nonrotatably to one end of the shaft 56, opposite ends of the shaft extending through suitable bearings (not shown) in

openings

60 and 62 formed in

upstanding leg portions

64 and 66 of the U-shaped bracketSO. In the dis closed embodiment, the roller 44 is provided with

pregap collars

68 and 70 preferably shrunk fit onto'the ends of the shell 52 as shown.

The lower roller 46 is similar in structure to the extent that it also includes a roller shell 71 and a flexible shaft 72. In this instance, however, the shell 71 is supported on the shaft 72 by, a pair of bearing assemblies 74. The bearing assemblies are preferably of the frictionless type and thus mayinclude rollers or balls 76 retained between an outer race 78 and an inner race 80. The shaft 72 extends at opposite ends through slotted

openings

82 and 84 formed in the

upstanding leg portions

64 and 66 of the bracket 50 and located in the coplanar

relation withthe apertures

60 and 62. The coplanar relation of the apertures and accordingly of the

shafts

56 and 72 will establish a linear working nip or bite between the

roller shells

52 and 71. Also, because the roller shell 71 of the lower roller 46 is supported rotatably on the shaft 72 by the bearing assemblies 74,

standing leg portions of the bracket 50.

The structural organization of the

rollers

44 and 46 as well as the U-shaped bracket 50 contribute not only to ease of manufacturing assembly but also to the achievement of a minimum preestablished force loading of the rollers oneagainst the other at the working gap or nip through which the film unit is passed during processing. In this latter respect, it is to be noted that the location of the shaft receiving apertures in the respective

upstanding leg portions

64 and 66 of the bracket are spaced at a distance slightly less than the spacing of the rotational axes of the

roller shells

52 and 74 are then located between the

legs

64 and 66 and the shaft 72 threaded through aperture 84, shell 71 and bearings 74 and aperture 82. The ends of shaft 72 are provided with grooves 86' which cooperate with a keyshaped configuration of

apertures

82 and 84 for securing the shaft72 against longitudinal or axial movement in the final assembly of the processor.

The upper roller shell after having the

pregap collars

68 and 70 shrunk fit at its ends, is assembled by aligning shaft 56 within roller shell 52 and pressing the couplers 58 onto the ends of the shaft 56 until they bottom out in the counterbores 54. The base of the counterbores establishes the ultimate axial position of the couplers in the roller 44. With the lower roller 46 having been as sembled with the bracket in the manner described above, the left end (as viewed in FIG. 2) of shaft 56 is passed through the bearing in aperture 60 and then the leg 66 is flexed outwardly until the other end of shaft 56 can be inserted through the bearing in aperture 62. Leg 66 is then released to allow it to return to its normal position, as shown in FIG. 2. The assembly is completed by coupling the gear 48 to one end of the shaft 56. Longitudinal movement of roller assembly 44 is restricted within narrow limits by the captive action of

legs

64 and 66 on the ends of roller shell 52. The preassembled processor is then ready for mounting in the a base 12 of the camera 10.

It is preferred that the

tubular rollers

44 and 46 be formed from stainless steel through a drawing opera tion since drawn tubular rollers are less costly to manufacture than solid rollers and further are of lighter weight resulting in a lower inertia during initial driving and braking. The

shafts

56 and 72 are preferably formed from stainless steel which is especially suited to perform the biasing function due to its spring characteristics.

By employing the

stainless steel shafts

56 and 72, bearing assemblies 74 and resilient couplers 58, the overall space necessary to accommodate the processing station in accordance with the present invention is reduced since the system for biasing the roller assemblies is located within the

rollers

44 and 46. The couplers 58 which are preferably formed from an elastomer, e.g., polyurethane, perform a dual function. First, driving torque is transmitted to the top roller 44 through gear 48, shaft 56 and through the couplers 58 which are frictionally retained on the shaft 56 and frictionally engage the inner peripheral surface of the roller 44. This frictional engagement, secondly, permits the couplers 58 to perform a clutching function for preventing transfer of excessive torque from the roller 44 to the shaft 56. Should an operator manually pull a filmunit through the rollers, the couplers 58 would permit relative rotation of the roller 44 with respect to the shaft 56 and therefore protect the mechanical drive components of the camera 10. Also, should a jam take place between the rollers, e.g., when more than one film unit is in the bite of the rollers, the couplers 58 would permit the shaft 56 to turn while the roller shell 52 remains stationary.

In operation, after an exposure cycle has been initiated, a picking mechanism (not shown) will initially move a film unit through the cassette egress opening 38 and between the

roller assemblies

52 and 54. The top roller assembly 52 will now be power driven through the gear train including end gear 40, roller drive gear 48 and shaft 56. As the film unit passes through the rollers, the processing fluid is spread evenly over the photosensitive composite and the shafts are further deflected. Since the

shafts

56 and 72 are deflected as the film unit passes between the rollers, bending is not transmitted to the rollers themselves, a uniform gap is maintained between the rollers, and a uniform pressure is applied to the film unit.

Reference is now made to FIGS. 5 and 6 of the drawings wherein is shown an alternative embodiment of the invention. The processing assembly includes an upper roller assembly 44 and a lower roller assembly 46' a U-shaped bracket 112 which in turn is secured by means (not shown) to a roller housing section 13'. Housing section 13 is pivotally mounted to the main body of the camera'much in the same manner that roller housing section 13 is pivotally coupled to housing section 12. Roller housing section 13 may be pivoted from the position shown in FIG. 6 wherein the

rods

56 and 72 are in a nonstressed condition and the roller assemblies 44' and 46 are spaced to allow loading of a film cassette 36 therebetween and into housing 12 and an operative position, as shown in FIG. 5, wherein the film chamber is secured and the roller assemblies 44' and 46 are located in juxtaposition with the

rods

56 and 72 stressed as in the preferred embodiment. When roller housing section 13' is latched to its operative position, suitable means, e.g., the abutment of the ends of

legs

100 and 108 and/or 102 and 110, are provided for establishing the correct distance between the axes of roller assemblies 44 and 46', thereby accurately controlling the stress on rods 56' and 72'. In other words, as the roller assemblies move toward each other, col lars 68 and 70' engage the shell 71' and transmit a bending force to rod 72' via bearing assemblies 74. Simultaneous therewith, the force on collars 68 and 70' is transmitted to rod 56 via shell 52 and. couplers 58. The stress on rods 56' and 72' continues to increase to a predetermined value, at which time the ends of legs and 108 and/or 102 and 110 abut to prevent any further movement of bracket 112 towards bracket 104. As in the previous embodiment described, the apertures 60' and 82 in

legs

100 and 108 and the apertures 62 and 84' in legs 102 and 114, respectively, are verti- Thus, it will be appreciated that the present invention provides an improved processing apparatus for use with self-developing photographic cameras and by which the abovementioned objects are completely fulfilled. It

will also be appreciated that further modifications and- /or changescan be made in the disclosed embodiments without departing from the invention. It is expressly in tended, therefore, that the foregoing description is illustrative only, not limiting, and that the true spirit and scope of the present invention will be determined by reference to the appended claims.

What is claimed is:

1. In a self-developing camera of the type in which an exposed film unit is processed by passage thereof between 21 pair of oppositely biased spreader surfaces, the improvement comprising: I I

a pair of rollers each including a tubular roller shell,

a flexible shaft extending through said shell and means for mounting said shells on said shafts rethereby providing a minimum pregap at said working nip between said pair of rollers.

3. The apparatus'as defined in claim 1 further including drive means operatively connected to at least one of said pair of rollers to rotate said rollers, said drive means including a'drive member fixedly secured to said flexible shaft of said one of said pair of rollers.

4. The apparatus as defined in claim 3 wherein said means for mounting said roller shell on said shaft connected to said d'rivemeans comprises a pair of resilient couplers, said couplers being in frictional engagement with the inner peripheral surface of said tubular roller shell and frictionally-supported on said driven shaft, thereby p'ermittingrelative rotation between the roller shell and the driven shaft to prevent transfer of excessive torque to said power drive means.

5. The apparatus as defined in claim 1 wherein said means for mounting one of said tubular roller shells comprises a pair of bearing assemblies about said shaft and contacting the inner peripheral surface of said tubular roller shell thereby permitting said tubular roller shell to rotate about said shaft.

6. The apparatus as defined in claim 1 wherein said means for supporting said ,shafts in a coplanar relationship comprise leg portions-said leg portions formed with apertures receiving the ends of said shafts, said apertures being vertically spaced equally on said leg portions a distance less than the radial distance between the axes of the tubular roller shells when said shafts are in said coplanar relationship. I

7. The apparatus as defined in claim 1 wherein said supporting means includes means for mounting said rollers for movement between a first position in which said rollers are out of engagement with each other and said shafts are in an unflexed condition and a second position wherein said rollersare in engagement with each other and said shafts are in said flexed condition to establish a predetermined force loading between said rollers.

8. The apparatus as defined in claim 7 further including means for preventing movement of said rollers beyond said second position. I

9. The apparatus as defined in claim 7 wherein said rollers when in said first position are spaced apart a distance sufficient to allow a film cassette tobe moved therebetween and into the camera.

10. A self-developing photographic camera for exposing and processing film units, said. camera comprising in combination: I

a base configured to receive film units for exposure in the camera; I

a'processor mounted adjacent said base to receive and process the film units film after exposure, said processor comprising a pair of rollers each including a tubular roller shell, a flexible shaft extending through said shell and means for mounting said shells on said shafts respectively; and I means for supporting said shafts in coplanar relation: ship to establish a working nip between said roller shells and to flex said shafts to bow about said mounting means, thereby to hold said roller shells yieldably one against theother at said nip under-the elastic restoration force of said flexed shafts to establish a predetermined force loading between said rollers. I

11. The photographic camera as defined in claim 10 wherein one of said rollers further includes means for I engaging the outer peripheral surface of the other of said tubular roller shells, thereby providing a minimum pregap at said working nip between said pair of rollers.

12. The photographic camera as defined in claim 11 wherein said engaging means comprise apair of pregap 'collars disposed on opposite ends of said one of said tuwherein said means for mounting said'tubular roller shell on said drive connected shaft comprises a pair of resilient couplers, said couplers frictionally engaging said drive connected shaft and frictionally engaging the inner peripheral surface of said one of said tubular roller shells, thereby preventing the transfer of excessive.

torque between said rollers and said drive means.

15. The photographic camera as defined in claim 14 wherein said means for. supporting. said shafts in coplanar relationship compriseslegportions, said leg'portions having apertures receiving the ends of said shafts,

said apertures being vertically spaced equally on each side of said processor a distance less than the radial disand a second position wherein said rollers are in engagement with each other and said shafts are in said flexed condition to establish a predetermined force loading between said rollers.

17. The photographic camera as defined in claim 16 further including means for preventing movement of said rollers beyond said second position.

18. The photographic camera as defined in claim 16 wherein said rollers when in said first position are spaced apart a distance sufficient to allow a film cassette to be moved therebetween and into said camera.

20. The apparatus as defined in claim 19 further including means for driving at least one of said rollersand means for limiting torque transmission between said one roller and said driving means.

21. The apparatus as defined in claim 19 including a bracket having upstanding leg members for supporting opposite ends of said shafts, and upstanding members being flexible to facilitate assembly of said rollers therein.

' 22.-The apparatus as defined in claim 19 wherein said supporting means includes means for mounting said rollers for movement between a first position in which said rollers are out of engagement with each other and said shafts are in an unflexed condition and a second position wherein said rollers are-in engagement with each other and said shafts are in said flexed condition to establish a predetermined force loading between said rollers.

23. The apparatus as defined in claim 22 further including means for preventing movement of said rollers beyond said second position.

Claims

1. In a self-developing camera of the type in which an exposed film unit is processed by passage thereof between a pair of oppositely biased spreader surfaces, the improvement comprising: a pair of rollers each including a tubular roller shell, a flexible shaft extending through said shell and means for mounting said shells on said shafts respectively; and means for supporting said shafts in coplanar relationship to establish a working nip between said roller shells and to flex said shafts to bow about said mounting means, thereby to hold said roller shells yieldably one against the other at said nip under the elastic restoration force of said flexed shafts.

2. The apparatus as defined in claim 1 wherein one of said roller shells further includes means disposed on said one tubular roller shell for engaging the outer peripheral surface of said other tubular roller shell thereby providing a minimum pregap at said working nip between said pair of rollers.

3. The apparatus as defined in claim 1 further including drive means operatively connected to at least one of said pair of rollers to rotate said rollers, said drive means including a drive member fixedly secured to said flexible shaft of said one of said pair of rollers.

4. The apparatus as defined in claim 3 wherein said means for mounting said roller shell on said shaft connected to said drive means comprises a pair of resilient couplers, said couplers being in frictional engagement with the inner peripheral surface of said tubular roller shell and frictionally supported on said driven shaft, thereby permitting relative rotation between the roller shell and the driven shaft to prevent transfer of excessive torque to said power drive means.

6. The apparatus as defined in claim 1 wherein said means for supporting said shafts in a coplanar relationship comprise leg portions, said leg portions formed with apertures receiving the ends of said shafts, said apertures being vertically spaced equally on said leg portions a distance less than the radial distance between the axes of the tubular roller shells when said shafts are in said coplanar relationship.

7. The apparatus as defined in claim 1 wherein said supporting means includes means for mounting said rollers for movement between a first position in which said rollers are out of engagement with each other and said shafts are in an unflexed condition and a second position wherein said rollers are in engagement with each other and said shafts are in said flexed condition to establish a predetermined force loading between said rollers.

8. The apparatus as defined in claim 7 further including means for preventing movement of said rollers beyond said second position.

9. The apparatus as defined in claim 7 wherein said rollers when in said first position are spaced apart a distance sufficient to allow a film cassette to be moved therebetween and into the camera.

10. A self-developing photographic camera for exposing and processing film units, said camera comprising in combination: a base configured to receive film units for exposure in the camera; a processor mounted adjacent said base to receive and process the film units film after exposure, said processor comprising a pair of rollers each including a tubular roller shell, a flexible shaft extending through said shell and means for mounting said shells on said shafts respectively; and means for supporting said shafts in coplanar relationship to establish a working nip between said roller shells and to flex said shafts to bow about said mounting means, thereby to hold said roller shells yieldably one against the other at said nip under the elastic restoration force of said flexed shafts to establish a predetermined force loading between said rollers.

11. The photographic camera as defined in claim 10 wherein one of said rollers further includes means for engaging the outer peripheral surface of the other of said tubular roller shells, thereby providing a minimum pregap at said working nip between said pair of rollers.

12. The photographic camera as defined in claim 11 wherein said engaging means comprise a pair of pregap collars disposed on opposite ends of said one of said tubular roller shells.

13. The photographic camera as defined in claim 10 further comprising: drive means for rotating said rollers, the shaft of at least one of said rollers being connected to said drive means.

14. The photographic camera as defined in claim 13 wherein said means for mounting said tubular roller shell on said drive connected shaft comprises a pair of resilient couplers, said couplers frictionally engaging said drive connected shaft and frictionally engaging the inner peripheral surface of said one of said tubular roller shells, thereby preventing the transfer of excessive torque between said rollers And said drive means.

15. The photographic camera as defined in claim 14 wherein said means for supporting said shafts in coplanar relationship comprises leg portions, said leg portions having apertures receiving the ends of said shafts, said apertures being vertically spaced equally on each side of said processor a distance less than the radial distance between the axes of said tubular roller shells when said shafts are in said coplanar relationship.

16. The photographic camera as defined in claim 10 wherein said supporting means includes means for mounting said rollers for movement between a first position in which said rollers are out of engagement with each other and said shafts are in an unflexed condition and a second position wherein said rollers are in engagement with each other and said shafts are in said flexed condition to establish a predetermined force loading between said rollers.

19. A roll-type spreader assembly comprising: a pair of rollers each including a tubular roller shell, a flexible shaft extending through said shell and means for mounting said shells on said shafts respectively; and means for supporting said shafts in coplanar relationship to establish a working nip between said roller shells and to flex said shafts to bow about said mounting means, thereby to hold said roller shells yieldably one against the other at said nip under the elastic restoration force of said flexed shafts.

20. The apparatus as defined in claim 19 further including means for driving at least one of said rollers and means for limiting torque transmission between said one roller and said driving means.

22. The apparatus as defined in claim 19 wherein said supporting means includes means for mounting said rollers for movement between a first position in which said rollers are out of engagement with each other and said shafts are in an unflexed condition and a second position wherein said rollers are in engagement with each other and said shafts are in said flexed condition to establish a predetermined force loading between said rollers.