US3575100A

US3575100A - Film developing apparatus

Info

Publication number: US3575100A
Application number: US685747A
Authority: US
Inventors: Edward B Krause
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-11-27
Filing date: 1967-11-27
Publication date: 1971-04-13
Anticipated expiration: 1988-04-13
Also published as: GB1232490A

Abstract

Automatic film developing apparatus for processing continuous length film, e.g. movie film. Film is pulled in a helical path about a series of upper and lower freely rotatable guide spools mounted on upper and lower shafts. An auxiliary drive roll underlies the peripheries of the spools on the upper shaft, which is resiliently biassed upwardly. When the film tension reaches some preselected value, the upper spools are pulled down into driving engagement with the auxiliary drive rolls, thus reducing the tension. One end of certain upper shafts may be blocked from vertical movement to provide smoother operation under certain conditions.

Description

United States Patent [72] Inventor Edward B. Krause 20 Meadow Wood Road, Trumbull, Conn.

06611 [21] Appl. No. 685,747 [22] Filed Nov. 27,1967 [45] Patented Apr. 13, 1971 {54] FILM DEVELOPING APPARATUS 7 Claims, 17 Drawing Figs.

Primary Examiner-Samuel S. Matthews Assistant ExaminerRobert P. Greiner AttorneyMattern, Ware and Davis ABSTRACT: Automatic film developing apparatus for processing continuous length film, e.g. movie film. Film is pulled in a helical path about a series of upper and lower freely rotatable guide spools mounted on upper and lower shafts, An auxiliary drive roll underlies the peripheries of the spools on the upper shaft, which is resiliently biassed upwardly. When the film tension reaches some preselected value, the upper spools are pulled down into driving engagement with the auxiliary drive rolls, thus reducing the tension. One end of certain upper shafts may be blocked from vertical movement to provide smoother operation under certain conditions.

Patentd April 13, 1971 6 Sheets-Sheet 1 INVENTOR.

1211:1111- *v l l hlu l l ll ul l l unu l l I! l H UK N Fl -1 I L: 1! 1m? 1. FL KE llll I liri +1: I

Edward B. Krause Patented I April 13, 1971 6 Sheets-Sheet 3 INVENTOR. Edward B, K; was? Mailer Warczfl Davis Paten ed "April 13, 1971' 6 Sheets-Sheet 5 INVEN Edward B, Kraus'e Patented Agni! 13, 1971 6 Sheets-Sheet 6 [dward 1i Kraus'e Alaii'erx Ware8-flawk resiliently urged away from auxiliary drive means. Preselected film tension pulls the spools into engagement with the auxiliary drive means, thus reducing the tension on the film.

PRIOR ART AND PROBLEMS Various types of automatic film processing apparatus are well known in the art. Typically, the film is passed in helical paths around a series of upper and lower guide spools, some of which are driven to advance the film with at least the lower spools being immersed in the various processing baths. A substantial amount of film presently being processed does not have sprocket holes along the edges, and is handled by driven friction type spools. Exemplary prior art Pats. are .lurska, US. Pat. No. 3,261,278 and Capstaff US. Pat. No. 1,664,735, wherein the guide spools are positively driven at all times. Since a large amount of film will be within the processing apparatus at any given time, control of the film tension is a serious problem. With prior art apparatus, tension within the film being treated can on occasion increase due to various causes until the film breaks, or excessive slackness can develop at some portion of the apparatus. These and other difficulties are avoided by the present apparatus.

It has been discovered that the above difficulties may be avoided according to the present invention by normally pulling the film through the treating apparatus by a takeup 'roll, with the film being guided on freely rotatable idler spools,

if means are provided to positively drive certain of the idler spools upon occurence of excessive tension.

OBJECTS Accordingly a primary object of the invention is to provide film developing apparatus which automatically maintains the film tension within prescribed limits. A further object is to provide apparatus of the above character wherein a minimum lower tension on the film is assured by normally pulling the film through the apparatus with a capstan pacer roll mechanism.

A further object is to provide apparatus of the above character wherein the film being processed is guided by a series of normally freely rotatable spools.

A further object is to provide apparatus of the above character wherein means responsive to excessive film tension automatically drives some of the normally freely rotatable spools so as to reduce excessive film tension.

A further object is to provide apparatus of the above THE. DRAWINGS For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 11 is atop plan view of an exemplary first embodiment invention;

FIG. 2 is a side elevation view of the FIG. I apparatus, partly broken away;

FIG. 3 is an enlarged detailed view of the upper left corner of FIG. 2, showing the preferred embodiment of the takeup capstan arrangement;

FIG. 4 is a sectional view taken along line 4-4 in FIG. '3, showing the rear of the takeup capstan arrangements;

FIG. 5 is an enlarged detailed view of the upper right corner of FIG. 2, showing the suspension arrangement of a typical upper spool shaft;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5, showing the suspension of the upper spool shaft and the construction of the preferred film guide spools, and the relation of the guide spools t0 the auxiliary drive roller;

FIG. 7 is a schematic perspective view of the upper spools and auxiliary drive assembly, showing a particular arrangement of stops for limiting the movement of certain spool shafts;

FIG. 8 is a schematic perspective view similar to FIG. 7, showing a different arrangement of stops for limiting the movement of certain spool shafts;

FIG. 9 is a sectional view, similar to FIG. 6, showing an alternative embodiment of stop mechanism;

FIG. I0 is a sectional view taken along line 10-10 in FIG. 9;

FIG. I1 is a perspective view, partly 'broken away, of the stop mechanism shown in FIG. 9;

FIG. 12 is a rear elevation view of an alternative embodiment wherein the spool shafts are mounted inside the tank for easier adjustment and maintenance;

FIG. 13 is a perspective view, partly broken away, of the embodiment shown in FIG. 12;

FIG. 14 is a rear elevation view of a further altemative embodiment of the inventionwherein the upper spools are immersed in a liquid bath;

FIG. 15 is a sectional view taken along line 15-I5 in FIG. 14;

FIG. I6 is a sectional view taken along line 16-16 in FIG. 14; I

FIG. 17 is a sectional view taken along line 17-17 in FIG.

DETAILED DESCRIPTION Referring particularly to FIGS. 1 and 2, film 20 is fed from a supply reel 22 at the front of the apparatus and is taken up on a takeup reel 24 at the rear of the apparatus. A series of processing tanks 26 between supply reel 22 and takeup reel 24 are filled with the various desired fluids for processing film 20. The leftmost tank 26, as viewed in FIGS. 1 and 2, may be the usual drybox, for drying the film prior to winding on reel 24. A plurality of generally horizontally upper shafts 28 are provided, supporting freely rotatable upper guide spools 30. The ends of shafts 28 are supporting in bearing assemblies attached to the sidewalls of tanks 26, as will be more clearly disclosed below. Underlying each upper shaft 28 is a corresponding lower shaft 32, supporting lower guide spools 34. As is best illustrated in FIG. 14, the center of each lower guide spool 34 is preferably aligned with a vertical plane halfway between adjacent spools 30. Spools 30 on a given upper shaft in cooperation with spools 34 on the corresponding lower shaft 32 provides means for guiding film 20 in a helical path transversely across the tanks.

As best shown in FIG. II, when film 20 has completed a helical path from one side of a tank to the opposite side, film 20 passes over the endmost upper spool 30 on a given shaft 28 to the endmost upper spool 30 on the adjacent upper shaft 28, so that the film feeds back and forth laterally across the tanks as it proceeds from supply reel 22 to takeup reel 24.

Motor 36 is mounted near takeup reel 24, and drives pacer capstan assembly 38 for forwarding film 20 through the apparatus. In the preferred embodiment of the invention, each of spools 30 are freely rotatable on upper shafts 28, and each of spools 34 are freely rotatable on lower shafts 32, so that film 20 is normally pulled through the apparatus by capstan assembly 38. The details of capstan assembly 38 are best illustrated in FIGS. 3 and 4. As shown in FIG. 3, capstan assembly 38 includes driven pacer roll 40 for frictionally forwarding film 20 to takeup reel 24. Roll 40 is driven from motor 36 by belt 42 and transmission 44. A nip roll 46 squeezes film 20 against the periphery of driven roll 40, to increase the traction for forwarding film 20. Idler wheel 45 is positioned to increase the contact of film 20 on the periphery of roll 40, further increasing the traction.

In the apparatus as thus far described, tension on the film at various places in the apparatus will tend to increase due to various causes to a level sufficiently high to injure or break the film occasionally. According to the present invention, auxiliary drive means are provided for automatically driving the appropriate normally freely rotatable spools 30 so as to maintain the tension within predetermined limits. A first embodiment for achieving this result is illustrated in FIGS. 1, 3, 5 and 6. As shown in FIG. 6, which affords a rear view of shaft 28, the left end of shaft 28 extends through vertical slot 48 in sidewall 50 of its tank 26. The end of shaft 28 is joumaled in bearing housing 52, which is mounted for vertical sliding movement between outwardly extending tabs 54 on mounting plate 53 attached to wall 50. Bolt 56 is threaded into bearing housing 52 and secured by locknut 58, and extends upwardly through an aperture in upper tab 54. Coil spring 60 is mounted between upper tab 54 and locknuts 62 on the upper end of bolt 56, whereby bolt 56, bearing housing 52, and shaft 28 are resiliently urged upwardly. The opposite end of shaft 28 is similarly resiliently mounted.

As best shown in FIGS. 3 and 6, an auxiliary drive shaft 64 underlies each shaft 28, and has its left end supported in bearing 66 mounted in wall 50. The opposite or right end of shaft 64 extends through the opposite tank wall to right angle drive unit 68 (FIGS. 1 and 3) driven from motor 36. A sleeve 70, which may be of rubber or the like, is mounted on shaft 64 to provide for frictional drive of the flanges of spools 30, as will be described.

Each upper shaft 28 and the corresponding lower shaft 32, which with their spools 3t) and 34 define a helical film guide path, constitute with the corresponding drive roller 64 positioned between them a film processing station. Any desired number of such stations may be cascaded, with at least the lower shafts 32 and spools 34 of each station being immersed in the various film processing fluids.

According to the first major aspect of the invention, when film tension becomes sufficiently high at a given station in the apparatus, upper shaft 28 is pulled down against the resistance of springs 60 until the flanges of spools 30 engage sleeve 70. Shaft 64 is driven at a speed such that the film on those spools 30 which engage sleeve 70 is forwarded at an overdrive speed somewhat higher than the peripheral velocity of capstan rolls 40 and 42, thus lowering the tension. The percentage overdrive thus given the film may generally be between I and 50 percent and more usually between 2 and I percent, with about percent being presently preferred. When the percentage overdrive is too high, spools 30 are repeatedly and rapidly pulled down to be driven by sleeve 70, resulting in excessive working" of the apparatus and rapid wear of the spool flanges. The film tension required to cause engagement between spools 3t) and sleeve 70 should be below the desired maximum tension for the film, and may be adjusted by moving Iocknuts 62.

It has further been discovered that smoother and more reliable operation is obtained if certain selected ends of particular shafts 28 are prevented from moving downwardly. The spools 30 on these selected ends are therefore prevented from being driven by shaft 64. This may be accomplished, as schematically illustrated in FIGS. 7 and 8, by stop collars 72 secured (for example by setscrews) to bolts 56 above upper tabs 54. In FIG. 7, collars 72 are employed at the exit ends of the first and second shafts 28, i.e., the ends from which the film is fed to the first spool 30 on the next succeeding shaft 28. Thus, the left end of the first shaft 28 and the right end of the second shaft 28 are prevented from lowering in response to film tension.

In FIG. 8, the exit end of each shaft 28 is prevented from lowering. The embodiments of FIGS. 7 and 8 are merely illustrative of preferred arrangements which have been found to operate well under particular conditions: selection of other arrangements to suit different processing conditions is well within the scope of one skilled in the art. Springs 60 and other details have been omitted in FIGS. 7 and 8 for simplicity of illustration.

FIGS. 9 through 11 illustrate a camming arrangement as an alternative to the collars 72 with which one or more ends of a selected shaft 28 may be easily blocked from vertical movement. Referring to FIG. 9, cam shaft 74 is mounted through frame member 76 so that its inner or leftmost end as viewed in FIG. 9 is somewhat lower than bearing housing 52. A simple cam surface 78 is mounted on shaft 74 to underlie housing 52. The opposite end of shaft 74 may be fitted with handle 80 to manually rotate shaft 74 to the desired position. In the position illustrated in FIGS. 9 and 1], bearing 52 is permitted to move vertically. If handle 80 and shaft 74 were rotated 180, the high portion of end 78 would be positioned beneath bearing 52, thus preventing bearing 52 and the end of shaft 28 from lowering in response to film tension. FIG. 10

illustrates the similar cam arrangement for the opposite end of shaft 28. The illustrated cams permit simple and rapid blocking of selected ends of shafts 28. Other means for accomplishing this function will occur to one skilled in the art.

FIGS. 12 and I3 illustrate an alternative embodiment of the invention, wherein the mounting assemblies for upper shafts 28 are mounted inside the tank for easier adjustment and maintenance. As shown therein, plate 53 is provided with a mounting bracket 82 which is attached to the inner surface of wall 50 by a pair of screws 84. Preferably, bracket 82 has slots 86 for receiving screws 84, so that upon loosening screws 84, brackets 82 and the entire shaft assembly 28 including plate 53 and bearings 52 can be lifted from the apparatus.

FIGS. 14 through 17 illustrate a further alternative embodiment of the invention wherein upper spools 30 are immersed in the liquid bath. In order to avoid the necessity to provide liquid seals for shaft 64 through wall 50, output drive shaft 88 of right-angle drive 68 extends through wall 50 above the liquid level. Sprocket wheel 90 is mounted on the end of shaft 88, and by means of chain 92 drives sprocket 94 on shaft 64. Accordingly, drive 68 is positioned above the liquid level, and the problems of providing sealing around shaft 64 are avoided.

The mounting of the right end of shaft 28 is shown in FIGS. I4 and 15. Drive housing 96 is mounted on the inside of wall 50, and encloses sprocket 90 and chain 92. Opposed brackets 98 are attached to the sides of housing 96 and define therewith opposed vertical slots for slideably receiving laterally extending portions 100 on plate 53. The upper ends of brackets 98 are bent horizontally to form supporting fingers I02 extending away from housing 96. The upper tab 54 on plate 53 overhangs supporting fingers 102, and has adjusting screws 104 threaded therethrough to rest on the upper surfaces of fingers I02. Accordingly, the lower limit of movement of plate 53 may be adjusted by means of screws 104.

The mounting of the left end of shaft 28 is shown in FIGS. l4, l6 and 17. A vertical C-shaped frame member 106 is mounted within the opposite sidewall 50, and includes horizontally extending supporting finger 108. Mounting plate 53 is slideably received within frame member 106, and includes adjusting screws 110 threaded through a portion 112 of upper tab 54 which overhangs supporting finger I08, so that the lower limit of movement of plate 53 and bearing 52 may be controlled by adjustment of screw I10. Shaft 28 and plates 53 in the FIGS. 14-I7 embodiment can be removed from the apparatus merely by lifting.

In the preferred embodiment of the invention, spools 30 and 34 are adapted for handling at least two film widths, while contacting only the edges of the film. This may be achieved by forming the spools with axially aligned circumferential grooves which are successively narrower and deeper near the center of the spools, as best shown in FIG. 14. The grooves thus define pairs of shoulders such as 114 for supporting a film of given width, and such as 116, for supporting a film of narrower width.

When the diameter of pacer roll 40 is selected to the optimum value for a given diameter of shoulders 116, as when processing narrow film, a changeover to wider film can be directly achieved by merely splicing the wider film to the end of the narrow film. The wider film will then be threaded through the apparatus on shoulders 114 without further intervention, although the effective overdrivefor the wider film will be higher than would be normally selected, resulting in more than the usual amount of engagement of spools 30 and sleeve 70. When the wider film has been threaded through the entire machine, the small pacer roll 40 may be replaced with one of larger diameter, resulting in smoother operation of the apparatus, at which time the speed of motor 36 may be reduced to maintain a constant film speed in the apparatus. It should be understood that the apparatus may include the customary elevators or film reserve supply units adjacent the supply reel 22 and the takeup reel 24. Since these devices are conventional in the art, they have not been illustrated. Exemplary film reserve supply units are disclosed in US. Pat.

No. 1,664,735,to Capstaff.

As a further important benefit resulting from the invention, the overdrive provided by shaft 64 and sleeve 70 automatically compensate for substantial tolerance variations among the diameters of shoulders H4 and 116, and among the spool flanges which engage shaft 64 or sleeve 70. Thus, if the designed overdrive is 5 percent, the spool flange diameters may be as much as nearly 5 percent smaller than the correct value, while still providing useful overdrive. This automatically compensates for wear of the apparatus, and permits considerable economies in production of the original parts.

It may be seen from the above description, together with the accompanying drawings that the disclosed apparatus automatically maintains the film tension within prescribed limits. A minimum amount of film tension is assured by pulling film through the several stations by means of capstan assembly 38. When film tension increases at particular stations to a-point above the desired level, shaft 28 at that station moves downwardly under the urging of the increased film tension until the peripheries of spools 30 are engaged and driven by sleeve 70 on shaft 64. The amount of film tension necessary to produce engagement between spool 30 and sleeve 70 may be adjusted by locknuts 62. The speed of shaft 64 is selected so that film'20 is fonivarded at a speed somewhat higher than the takeup speed of capstan assembly 38, so that tension is automatically reduced whenever it exceeds the 1 predetermined level. The particular spools illustrated in the drawings permit handling of more than one film width, with the film being supported only along the edges. Smoother and more reliable operation of the disclosed apparatus may be achieved under particular conditions by blocking vertical movement of selected ends of certain shafts 28, as by the exemplary collars 72 (FIGS. 7 and 8), or by the illustrated cams disclosed in FIGS. 9 through Ill. Various other modifications of the apparatus are disclosed for permitting the ease of maintenance or adjustment, such as the mounting assemblies illustrated in FIGS. 13 through 17. The embodiment disclosed in FIGS. 114 through 17 permits operation with

spools

30 and 34 beneath the liquid level. The disclosed apparatus in its several embodiments is simple and economical in construction and is reliable and efiicient in operation.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be inte reted as illustrative and not in a lir nitin sense.

It is also 0 be understood that the following c aims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

lclaim:

1. Film processing apparatus, comprising:

A. at least one film processing tank;

B. a first shaft mounted transversely across said tank and supporting a plurality of freely rotatable first film guide spools which are substantially restrained from radial motion;

C. a second shaft generally parallel to said first shaft and supporting a plurality of freely rotatable second film guide spools, said first and second spools defining a helical path for guiding film to be processed;

D. film supply means for feeding film to said helical path;

E. film drawing means for drawing film from said film supply means through said helical path at a constant rate;

F. an auxiliary driven drive roll mounted parallel to said first shaft and adjacent said first spools, and said drive roll when in contact with said first spools adapted to drive film engaged therewith at a greater rate than film is drawn by said film drawing means; and

G. means independently resiliently mounting each end of said first shaft, whereby each end thereof is capable of independent movement towards said drive roll while the other end remains fixed and whereby upon occurrence of excessive film tension at one of said first spools, it and said first shaft will be pulled toward said drive roll until said one of said first spools contacts and is driven by said drive roll to thus relieve said excessive film tension condition.

2. Film processing apparatus as defined in claim 1, wherein said first shaft is mounted for free rotation about the axis of rotation of said first spools.

3. The apparatus defined in claim 1, further characterized by blocking means for selectively preventing or permitting downward movement of at least one end of said upper shaft.

4. The apparatus defined in claim 3, wherein said blocking means includes a camming surface selectively positionable beneath at least one end of said upper shaft.

5. The apparatus defined in claim I, wherein the speed of said drive roll is so selected that film is forwarded at a speed between I and 50 percent higher than said constant rate.

6. The apparatus defined in claim 1, wherein the speed of said drive roll is so selected that film is forwarded at a speed between 2 and 10 percent higher than said constant rate.

7. The apparatus defined in claim 1, wherein the speed of said drive roll is so selected that film is forwarded at a speed substantially 5 percent higher than said constant rate.

Claims

1. Film processing apparatus, comprising: A. at least one film processing tank; B. a first shaft mounted transversely across said tank and supporting a plurality of freely rotatable first film guide spools which are substantially restrained from radial motion; C. a second shaft generally parallel to said first shaft and supporting a plurality of freely rotatable second film guide spools, said first and second spools defining a helical path for guiding film to be processed; D. film supply means for feeding film to said helical path; E. film drawing means for drawing film from said film supply means through said helical path at a constant rate; F. an auxiliary driven drive roll mounted parallel to said first shaft and adjacent said first spools, and said drive roll when in contact with said first spools adapted to drive film engaged therewith at a greater rate than film is drawn by said film drawing means; and G. means independently resiliently mounting each end of said first shaft, whereby each end thereof is capable of independent movement towards said drive roll while the other end remains fixed and whereby upon occurrence of excessive film tension at one of said first spools, it and said first shaft will be pulled toward said drive roll until said one of said first spools contacts and is driven by said drive roll to thus relieve said excessive film tension condition.

5. The apparaTus defined in claim 1, wherein the speed of said drive roll is so selected that film is forwarded at a speed between 1 and 50 percent higher than said constant rate.