US 2263380 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Nov. 18, 1941.
A. COLEMAN PHOTOGRAPHIC HACHINE Filed June 15, 1939 3 Sheets-Sheet 1 r. Albart' GoLemM.
Nov. 18, 1941. A. COLEMAN 3 3 PHOTOGRAPHIC MACHINE Filed June 15, 1939 3 Sheets-Sheet 2 Fig. 3
Abborhel Nov. 18, 1941. A. COLEMAN 2,263,380
PHOTOGRAPBIC MACHINE Filed June 15, 1939 v 3 Sheets-Sheet 3 Inuetor.
Patented Nov. 18, 1941 UNITED STATES PATENT 'OFFICE Application June 15, 1939, Serial No. 279291 In Great Britain May 15, 1939 s Claims.
Photographic machines delivering pictures in a few minutes are known to convey the sensitized sheets of paper, film or other material to the baths and from one bath to the other up to final delivery, automatically.
For the purpose of 'such transport various systems are in use, utilising either chains, rollers, ribbons and hooks or a combination of them, but all imparting to the sheets a movement that subjects them to efforts from sliding, pushing, pulling or rubbing on the various parts of the baths with which they come into contact.
The present invention realises a method by means of which the sheets of sensitized material are transported, while in the baths, by a mechanical system which allows them to remain immobile while thus transported and excludes,jn suppressing all pushing, pulling or sliding of the sheets, the-possibility of their rubbing, Scratching and crushing as they are not allowed to come into contact with any parts of the baths whatsoever.
According to this invention the sheets of sensitized material while in the baths are held between the inner borders of two endless steel ribbons which leave the sheet entirely exposed to the bath. These ribbons traverse the bath into contact with each other; only said ribbons receive all strains and rubbing from the tank members of the bath.
The steel ribbons are stretched by means of rollers and maintained on a curved path between said rollers by means of suitable convex surfaces on which they slide, so that their clamping action is maintained.
The rollers are not carried directly by the bath tank but are Secured to a frame which is immersed into the bath. Each sheet in each bath is taken in between the ribbons, passes downwards and upwards and is then released. A continuous movement is imparted to the belts by a driving roller mounted at the upper part of the driving mechanism and having its horizontal spindle rotatably supported by the frame of the apparatus. The tank of the apparatus is raised and hung to the frame instead of lowering the frame into the bath, thus facilitating maintenance and control of the conveyor.
The driving roller is removably Secured to its rotating spindle, so that each tank and its conveyor may easily be removed from its spindle independently of the remaining tanks.
The annexed drawings show an embodiment of this invention.
Fig. 1 shows diagrammatically the conveyor with endless ribbons according to this invention.
Fig. 2 shows the particular form of the endless steel ribbons. I
Figs. 3 and 4 are cross and longitudinal section respectively, relatively to the driving axis of a bath for sensitized material of an automatic or semi-automatic camera.
As shown in Fig. 1, two endless ribbons a, b are stretched each between apair of parallel rollers c, d and touch each other at their inner edges a' and b'; the sheet introduced between said edges is carried through the bath.
The contact between the edges a' and b' is ensured by the fact that one of the ribbons slides on a convex surface c', the other ribbon, being stretched between its rollers, is forced to adhereto and take the exact curvature of the former. The ribbons are of wide U-shaped section (Fig. 2) the U branches of the two ribbons are face to face and between them the sheets s is gripped along two edges. In the U web are formed large openings, so that the ribbon is constituted by two continuous marginal bands m and n connected together by a plurality of cross members r with turned-in ends for connection to the bands. The ribbon maintains thus the necessary flexibility to adapt itself to the curvature of rollers of small diameter while the liquid (or gas) of the bath may circulate freely on both surfaces of the sheet s.
The conveyor (Figs. 3 and 4) comprises two plates l connected and spaced apart by means of an upper crosspiece la and lower crosspiece lb. Both plates are of elongated form and arranged vertically in the apparatus; they are hung to the spindle 3 fixed to a crosspiece 4 of the apparatus frame by means of a sleeve 2 Secured to the rear plate. The plates carry a tank 5 by means of two hooks 6 engaging lugs 1 of the tank; the tank may thus be easily removed without taking away the conveyor from the crosspiece 4. The plates carry at their upper part a cover 8 Secured by means of screws; resilient blades 9 act as spacers between the tank and plates.
The bath tanks 5 (Fig. 3) are placed adjacent to each other but for a narrow gap' due to the presence of blades III (Fig. 3) ensuring the vertical position of the tanks and carried by the frame of the apparatus.
The conveyor is constituted by a driving and a driven ribbon. The driving ribbon Il is stretched (Fig. 3) between a large upper driving roller IZ, rotatable on a sleeve 2 and a small lower roller !3 rotatable within bushings of a !ork N (Fig. 4), the stem IS of which slides telescopically, under the action of a spring li. within a tubular support I'I carried by the crosspiece lb; the driving ribbon, when released from or returned to the upper roller l2, passes over the rollers of smaller diameter i& that deflect it towards the central plane of the rollers l2-l 3. The driving ribbon H between the lower roller 3 and rollers s slides both on the upward and downward branch on convex blades i! secured to the plates I and provided with wide openings (not shown in Fig. 4).
The driven ribbon 20 forms two interlinked v's, the outer one being comprised between the upper rollers s and lower roller 2| of large diameter and the inner one between said rollers i! and the roller l3; the driven ribbon is superposed on the driving ribbon on the length between the rollers I& and roller 2l; both ribbons are maintained in the stretched condition by a spring IS once the exact initial tension has, been adjusted. The side walls of the cap 8 are provided with two horizontal slots in planes nearly tangential to the rollers s; in said slots are fltted sheet guides 22, through one oi' which is passed the-sheet to be treated in the bath 5. said sheet, gripped by the ribbons II and 20, as shown in Fig. 1, is first carried downwards and then upwards and passed to the next sheet-guide. The sheet does not undergo any stress in the bath and does not come into contact with any part of the tank. The outlet slot from a bath registers with the inlet slot in the next bath, so that the sheet passes automatically from one to the next bath; obviously the ribbons in the various baths move at the same speed, the driving rollers |2 being positively connected to each other.
The driving roller |2 is actuated by a shaft 23 freely rotatable within the supporting spindle 3, which is provided at its end with a prismatic boss zaa carrying a flywheel 24, fixed by a. nut or resilient stop; the shaft is connected to the roller by means of radial pins 24' extending from the roller and engaging axial notches in the flywheel. Removal of the fiywheel 24 stops the conveyor, which is very advantageous for the control of the machine.
The bath is provided with a. stirring device constituted by a double screw 25 carried by a sleeve l'l of the crosspiece and set into rotation by a roller [3, which is suitably constituted by two sections keyed on a shaft l3a, by means of a pair of bevel gears 26, a Vertical shaft 21 and another pair of bevel gears. The shaft 21 is made of two sections connected together by a joint allowing the shaft to adapt itself to the deformations of the spring IS. The tank 5 is provided with a filler 28, an overfiow pipe 29 and a bottom plug 30.
The constructional details of the conveyor, tank and driving mechanism may of course be modified according to practical requirements.
What I 'claim is:
1. Conveyor for sheets to be passed through treatment baths, comprising two endless ribbons of U-section, the flanged ends of the branches of the ribbons being into contact with each other during part of the travel of said ribbons and the web of said ribbons being provided with large openings, means for Operating one of said ribbons, the other being carried into motion by friction with the former, the sheet being gripped along its side edges between said branches, transported through the bath and released at the end of its travel through the bath.
2. Conveyor for sheets to be passed through treatment baths comprising a driving roller. a driven loose roller, an endless driving ribbon passing over said rollers, two guiding rollers arranged in proximity to the driving roller on each side of said driving ribbon, a floating stretching roller under the driven roller, an endless driven a ribbon passing over the driven roller, both guiding rollers and tensioning roller in such inanner as to form two V's one inside the other, the portion of the driven ribbon !orming the inner V beinginto contact with the driving ribbon. convex guiding surfaces for the contacting lengths oi' the ribbons, a passageway for the sheets to permit their insertion between the two ribbons, said passageway being arranged between the driving roller and one of the guiding rollers and means arranged between the driving roller asrd t;the other guiding roller for releasing the 3. Conveyor, as claimed in claim 2, in which the endless driving ribbon and the endless driven ribbon are of U-section, the flanged ends oi the branches of said two ribbons being into contact with each other along the portions between the driven roller and the guidingrollers, the web of said ribbons being provided with large openings extending from one to the other branch.
4. Conveyor, as claimed in claim 2, comprising a resilient stretohing device for supporting the driven roller and maintaining both endless ribbons in the stretched condition.
'5. Conveyor i'or sheets to be passed through treatment baths, comprising a driving roller, a
hollow fixed spindle, on which said roller is roi tatably mounted, a driving shaft passing through said spindle, means for coupling in an easily removable manner said shaft 'with said roller without discontinuing the rotation or the driving shaft, a driven roller, an endless driving ribbon passing over said rollers, two guiding rollers arranged in proximity to the driving roller on each side of said driving ribbon, a floating stretching roller under the driven roller, anendless driven ribbon passing over the driven roller, both guiding rollers and the tensioning roller in such manner as to form two V's one inside the other, the portion oi' the driven ribbon forming the inner v being into contact with the driving ribbon, convex guiding surfaces for the Contacting lengths of the ribbons, a passageway for the sheets to permit their insertion between the two ribbons, said passageway being arranged between the driving roller and one of the guiding rollers and means arranged between the driving roller 'and the other guiding roller for releasing the sheet.
6. Conveyor for sheets to be passed through treatment baths, comprising a driving roller, a hollow fixed spindle, on which said roller is rotatably mounted, a driving shaft passing through said spindle, means for coupling in an easily removable manner said shaft with said roller without discontinuing the rotation of the driving shaft, a driven roller, an endless driving ribbon passing over said rollers, two guiding rollers arranged in proximity to the driving roller on each side of said driving ribbon, a floating stretching roller under the driven roller, an endless driven ribbon passing over the driven roller, both guiding rollers and the tensioning roller in such manner as to form two V's one inside the other, the portion of the driven ribbon forming the inner V being into contact with the driving ribbon, convex guiding surfaces for the contaeting lengths of the ribbons, supporting piates for said rollers supported by said fixed spindle, convex guiding surraces for the contacting portions o! the ribbons, said surfaces being supported by said plates, a guiding channel for the sheets to permit their insertion between two ribbons on one side of the conveyor and a guiding channel tor'receiving the sheet issuing from the bath.
7. conveyor as claimed in claim 6, comprising a stirring device arranged between said convex guiding surtaces and a transnitting device adapted to transmit the motion rrom said driven roller to said stirring device.
8. A device for conveying sheets through a 15 5 ranged between said flanged ends being provided with large openings, means ior .positlvely driving one of said belts. while the second belt is driven by Irictional contact with said first. driven belt, said belts gripping said sheets at their edges 10 while leaving practically the entire surface of said sheets free to the access of the bath, said conveyor belts transporting the sheets through the bath and releasing the sheets at the end of their travel through the bath.