US1921487A

US1921487A - Method of and apparatus for feeding webs or strips

Info

Publication number: US1921487A
Application number: US484222A
Authority: US
Inventors: Smith Kenneth Stuart
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1929-11-13
Filing date: 1930-09-24
Publication date: 1933-08-08
Anticipated expiration: 1950-08-08

Description

g- 8, 1933- K. 8. SMITH 1,921,487

METHOD OF AND APPARATUS FOR FEEDING WEBS OR STRIPS Filed Sept. 24, 1950 2 Sheets-Sheet 1 -f 1933- K. s. SMITH 1,921,487

METHOD OF AND APPARATUS FOR FEEDING WEBS OR STRIPS I Filed Sept. 24, 1930 2 Sheets-Sheet 2 Jwuentoc Lien/n6 ih AS. b'rniih,

Patented Aug. 8, 1933 UNITED STATES METHOD OF AND APPARATUS FOR FEED- ING WEBS OR STRIPS Kenneth Stuart Smith, West Wimbledon, Eng land, as'signor to Eastman Kodak Company, Rochester, N. Y., a Corporation of New York Application September 24,1930, Serial No. 484,222, and in Great Britain November 13, 1929.

6 -Clairns.- o1. 271-2.2

This invention relates to the feeding of webs or strips of flexible material such as woven fabrics, paper, celluloid film or the like and has for its chief object to provide an improved method and apparatus for feeding such webs or strips through a liquid without subjecting them to excessive tension. Y

It is often necessary in connection with the manufacture or treatment of long bands of relatively delicate material such as paper, woven fabric, celluloid film or the like to pass the band relatively slowly through one or more chambers in which the band is subjected to thesection of a liquid as for example when the band is first coated with some substance or impregnated with a solution and subsequently permitted to dry'before being cut off in short lengths or wound upon a take-up roller.

Insuch case the band is as a rule made to assume a number of loops, the upper end of each loop being passed over a roller which is positively driven to impart the necessary feed to the strip without subjecting the whole length of the strip to tension. Such a feed mechanism is necessarily complicated and this is particularly the case where the band under treatment is for the main part immersed in a solution, as in the case of photographic film which is undergoing the process of development, fixing, washing etc.

According to this invention the method of feeding a web or strip of flexible material in a series of loops through a liquid without subjecting the total length of all the loops to tension. consists in successively extending certain loops. for example alternate loops. and in maintaining suificient tension in the length of material between the last loop and the final winding reel or its equivalent to take up the slack which is thus intermittently formed between them.

The upper and lower end of each loop is sup ported upon a frame or strainer so that the Whole loop can be extended or shortened when the frame is moved.

The apparatus by which the method is carried out conveniently comprises a number of similar frames including a plurality of movable assemblies having transverse rollers at the upper ends of the frames and including a plurality of rollers mounted in alignment with the rollers of the movable assembly to form the lower ends of the frames. An actuating means alternately moves alternate movable assemblies so that the loops are alternately extended and shortened. The web is then conducted to a web receiving means which includes a take-up roll frictionally driven to take up the slack in the last loop only and a ratchet mechanism preventing reverse rotation of the take-up roll. The frictional drive for the take-up roll does not have sufiicient driving power to draw the web through the loops with consequent increasing tensions in the loops.

The invention is particularly applicable to the development of a photographic film other than cinema or like film having perforated margin,

and one form of apparatus embodying the invendeveloping, rinsing, fixing and washing the film,

and a chamber A in which the film is finally dried as by directing a current of warm air upwards through a conduit A Rotatably mounted in bearings B above the tanks is a camshaft B,

a similar camshaft B being mounted in bearings B above the drying chamber A. The camshafts B, B which can be simultaneously driven by a motor C through chain or belt gear C are provided with a number of cams B (Figure 2) and similar straining frames are arranged side by side in the tanks and the drying chamber, each cam cooperating with the movable assembly of each frame. The cams are so set that when the camshafts B, B are rotated by the motor C, the upper movable assembly, broadlydesignated as D,

of each alternate frame or group of frames is raised whilst the similar parts of intermediate frames are simultaneously lowered.

The cams B are preferably circular and are eccentrically mounted in axial spacial relation on shaft B. The greatest eccentricities or maximum portions of alternate cams B are in the same position or in alignment along shaft B. Also the maximum portions of adjacent cams B are 180 displaced from each other on shaft B. Thus the movable assemblies D are alternately moved from lowermost to uppermost positions or vice versa during 180 revolution of shaft B.

One construction of the straining frame for dealing with two strips simultaneously is'illustrated in Figure 2 and comprises two vertical tubular guide members D normally fixed to the tank by means of horizontal arms D Mounted to reciprocate in these normally fixed guides is -a movable assembly D comprising parallel plungers D connected by a transverse rod D carrying a central roller D Freely rotatable on the outer ends of the transverse rod D are two rollers E, two similar rollers E being rotatably carried on spindles E at the lower end of the fixed guides. The rotation of the camshaft results in the cam B engaging the roller D and thereby moving the transverse rod and the rollers E upwards against the action of springs D The upper and lower rollers E, E on each straining frame are in vertical alignment and the arms D are so arranged that any one straining frame can be bodily removed from the tank Without interfering with the straining frames on eitherside thereof. The straining frames provided in the drying chamber A are, in the construction illustrated in Figure 1, shown as permanently fixed relatively to the chamber, the lower portion of the tubular members D being in this case omitted and the lower rollers of each frame carried on fixed spindles.

The strip of film F--which may be made by suitably securing together a number of relatively short lengths of the same or different widthis led from a roller F to a gravity tension device F and thence over the upper roller E of the first frame in the developing tank A as shown in Figure 1. The film is then led downwards and slightly backwards so as to pass under the corresponding roller E at the lower end of the same frame before being led up again to the upper roller ofthe next frame. The film is led in this manner over the frames in the remaining tanks and the drying chamber and finally to a winding-on or take-up reel G. The reel G is driven from the camshaft B through a friction drive (not shown) which maintains a definite tension in the final strip or length between the last roller E and the take-up reel G. A ratchet and pawl mechanism G prevents reverse or unwinding rotation of roll G.

When the motor C is set in motion the cams B raise and lower alternate movable assemblies D in each straining frame so that alternate loops of the film are extended whilst the intermediate loops are shortened, except where a junction occurs between the tanks when the two frames adjacent to this junction are made to move simultaneously and not alternately. Thus the slack of film produced by one loop which has just been extended is taken up and thereby transferred to the next loop by the ascending movable assembly D. In this manner the slack is in turn passed down the whole series of loops until it is wound on the take-up reel G.

The rollers E, E are of hour-glass shape as shown so as to accommodate a film of varying width and, as the rollers are free to revolve upon their spindles, any relative movement between the film and the rollers and consequent damage to the film is prevented. The tanks are conveniently wholly or partially sunk so that the upper end of each loop is at a convenient level for manipulation and inspection and if desired a horizontal bar or the like may be provided above the tanks so that any selected straining frame with the loop of film it carries can be suspended as, for example, when the tank is emptied or cleaned out.

The drying chamber may be of some known type and instead of the warm air being directed upward through the conduit A a fan may be disposed in the upper wall of the chamber above an elastic heater so arranged that warm air gently descends through the drying chamber in which the film, after being washed, is slowly fed in loop formation as above described.

The web receiving means may be capable of adjustment to vary the effective take-up of the reel G whereby the length of time for which the film is subjected to treatment in the tanks and in the drying chamber can be adjusted as desired.

It will be appreciated that the arrangement may be such that a single cam-shaft operates all the movable assemblies both in the tanks and drying chamber and that instead of alternate assemblies D being raised and lowered the cams may be set to move the assemblies D in any other desired sequence, the setting and/ or shape of the cams being varied accordingly. Further, instead of the film being wound upon a reel which is frictionally driven and associated with a ratchet or like uni-directional device, the film, after being dried, can be passed between two rollers by which it is gripped prior to being cut off or conveyed elsewhere. Although the invention has been described with particular reference to the developing, fixing, washing and drying of photographic film, it is equally applicable to all cases in which a web of paper, fabric or other relatively fragile strip material is subjected to the action of a liquid as it is gradually fed through one or more chambers.

Having now particularly described and ascertained the nature of my invention and in what manner the same is to be performed, I declare that what I claim is:--

1. A method of advancing a web of flexible material which comprises forming the web into a plurality of loops, alternately extending and shortening alternate loops of the web with respect to each other and winding up one end of the web at a definite tension sufficient to take up the slack in the last loop only, whereby the web is intermittently advanced.

2. A method of advancing a web of flexible material, which comprises forming the web into a plurality of vertical loops, alternately raising and lowering alternate loops and winding up the web at a tension sufiicient to take up the slack in the last loop but not great enough to draw the web through the other loops whereby the web is intermittently advanced.

3. In an apparatus for advancing a web of flexible material, the' combination with a plurality of frames adapted to conduct the web in a plurality of loops through the apparatus, each frame including a stationary roller and a movable assembly having a roller, of an actuating means for alternately moving the alternate movable assemblies with respect to each other and including a cam shaft and a plurality of axially spaced cams thereon, said cams being timed to reciprocate said movable assemblies alternately with respect to each other, and a web receiving means including a roll frictionally driven and adapted to take up the slack only in the adjacent loop.

4. In an apparatus for advancing a web of fiexible material, the combination with a plurality of frames adapted to conduct the web in a plurality of loops through the apparatus, each frame including a stationary roller and a movable assembly having a roller, of an actuating means for alternately moving the alternate movable assemblies with respect to each other and including a cam shaft and circular cams eccentrically mounted in axial spaced relation on said cam shaft and in operative relation to respective movable assemblies and a web receiving means including a roll frictionally driven and adapted to take up the slack only in the last loop.

5. In an apparatus for advancing a web of flexible material, the combination with a plurality of frames adapted to conduct the web in a plurality of loops through the apparatus, each frame including a stationary roller and a movable assembly having a roller, 0! an actuating means for alternately moving the alternate movable assemblies with respect to each other and including a cam shaft and circular cams eccentri-' cally mounted in axial spaced relation on said cam shaft and in operative relation to respective movable assemblies, alternate cams having the maximum portions thereof aligned and displaced 180 from the maximum portions 01' the adjacent cams, and a web receiving means including a roll frictionally driven and adapted to take up the slack only in the last loop.

shaft and a plurality of cams axially spaced on,

said shaft, in operative relation to each movable assembly and adapted to raise alternate assemblies against the action of said springs and a web receiving means including a roll frictionally driven and adapted to take up the slack only in the last loop.

KENNE'I'H STUART SMITH.