US2459362A - Photographic printing apparatus having a rotary light-transmitting cylinder and an endless belt bearing against the cylinder - Google Patents

Description

Jan, 18, 1949. F H, CARY 2,459,362

PHOTOGRAPHIC PRINTING APPARATUS HAVING A ROTARY LIGHT TRANSMITTING CYLINDER AND AN ENDLESS BELT BEARING AGAINST THE CYLINDER Filed June 2, 1945 3 Sheets-Sheet 1 j' "RA Jan. 18, 1949. x F. H. CARY 2,459,362

PHOTOGRAPHIC'PRINTING APPARATUS HAVING A ROTARY LIGHT TRANSMITTING CYLINDER AND AN ENDLESS BELT BEARING AGAINST THE CYLINDER f Filed June 2, 1945 s sheets-sheet 2 Jan. 18 1949. F H, CARY PHOTOGRAPHIC'PRINTING APPARATUS HAVING A ROTARY LIGHT TRANSMITTING CYLINDER AND AN ENDLESS BELT BEARING AGAINST THE CYLINDER 3 Sheets-Sheet 3 Filed June 2, 1945 Patented Jan. 18, 1949 UNITED STATES PATENT OFFICE Francis H. Cary, Warwick, R. I., assignor to Builders Iron Foundry, Providence, R. I., a corporation of Rhode Island Application June 2, 1945, Serial No. 597,186

3 Claims.

The present invention relates to a contact printing apparatus for photographic printing on light sensitive flexible sheet materials, such as papers, zinc sheets, and the like.

In the art of printing upon photographic or light sensitive sheet materials, it is important to provide for intimate registry and contact between the light sensitive materials and the flexn ible original sheets (such as paper negatives, bearing the image through which the exposure light is directed thereon) and to provide for rapidly contacting and positioning the sheets, passing them through the exposure light, and subsequently discharging them without undue or unequal strains and stresses upon them. It is also important that the light sensitive materials shall not be subjected to light prematurely nor after being withdrawn from the printing apparatus, whether it be direct or diffused, It is of great importance that the exposure throughout the areas of intended exposure and throughout the period of time allowed shall be uniform with respect to angle of contact and intensity and the aggregate quantity of exposure light applied, and also controllable in respect of the characteristic wave lengths of the exposure light.

It is accordingly an object of the present invention to provide a contact printer which shall afford these conditions for photographic printing, with improved operation and improved results in the photographic prints obtained. Further objects will appear from the following disclosure.

A representative embodiment of the apparatus of the invention will be described with reference to the accompanying drawings in which Fig. 1 is a plan View of the printing apparatus, together with a motor for operating the driving mechanism and a variation control for regulating the current passing through the lighting cells of the printer, the cover being removed;

Fig. 2 is a vertical cross-section of the printer in the plane 2 2 of Fig. 1, with the cover in place;

Fig. 3 is a view of the apparatus as seen in the direction of the arrows 3 3 in Figs. 1 and 2;

Fig. 4 is a detail view of three modifications of the illuminating units shown in cross-section in Fig. 2 and lengthwise in Fig. 3;

Fig. 5 is a front view of a modied embodiment of the invention;

Fig. 6 is a section on line 6 6 of Fig. 5;

Fig. 7 is a detail section on line 'I 'I of Fig. 5; and

Fig. 8 is an elevational view of the right side of Fig. 7.

In the particular embodiment shown in Figs. 1 to 4 the apparatus comprises a base I upon which may be mounted an electric motor 2 adapted to drive through its shaft 3, and a suitable train of reducing gears 4 4, the shaft 5 which passes through and is journaled in the vertical end walls 5 6. Between the end walls is a light-tight housing including a front wall 8, leaving the front aperture 9 openv for the introduction and removal of the printing paper and negatives, as will be described.

Also journaled in the end walls 6 6 are three other shafts IIJ, II and I2, parallel and similar to the shaft 5, but not positively driven. The shaft 5 and rollers I0, I I and I2 are adapted to receive an endless belt I3 which extends throughout the lengths of the rollers and is provided at its marginal edges with external flanges M M of iiexible rubber, which extend nearly to each end of the rollers. Mounted within a re-entrant loop I5 of the belt (between the roller I2 and shaft 5) is mounted a floating transparent (or light trans-- missive) hollow glass or plastic cylinder I6, the ends of which are retained in position between the flanges III-I4 (which are here inwardly disposed) and which rotates freely in said loop upon driving the belt I3 longitudinally, by means of the shaft 5 and over the rollers I Sl, II and I2, in the direction of the arrows.

Above and adjacent to the ends of the roller II (and mounted upon the under surface of a crossbar as shown in Figs. 1 and 2) are a pair of xed guide rolls Il II which are spaced apart to correspond to the width of the belt I3 between the external flanges I d IlI along its marginsthereby to engage the inner opposed surfaces of the flanges III-I4. This is eiected with but slight contact so long as the belt I3 is running taut and true over the rolls. But the xed guide rollers will exert a gradual adjusting and aligning pressure upon it, as soon as either iiange I4 (or the belt I3) tends to run out of alignment, and to return it proptly to its true running position with out any possible tendency to cause binding and before any appreciable degree of correction is required.

Inside the cylinder IS is a longitudinal partition having at the right end (Fig. 3) an integral flange 30 which is attached to the end wall 6 by screws 3I (Fig. 2). At the other end a plate 32, having the same outline as flange 30, is supported by a thumb-nut 33 on a plate 34 which in turn is mounted on end wall 6 by thumbnuts 35. Extending around the circular edges of end plates 30 and 32, from the upper edge of par- 3 tition I8 to its lower edge, are rings 25 and 36 which are secured by soldering or welding to the edges of the parts i8, 313 and 32. Strips 3l of felt are mounted on the rings 25 and 36 to obstruct light from passing between the rings and the cylinder I6 and other strips I9 are mounted on the upper and lower edges of partition I8 to prem vent the escape of light over the upper and lower edges of the partition. By making the belt i3 opaque it serves to obstruct light passing through the transparent cylinder I6.

On the inner surface of the panel I8 (i. e. opposite from the aperture Si) and within the cylinder i6 are mounted one or more light cells such as incandescent light tubes Zit, 2l which extend throughout the length of the cylinder and are connected through end walls 6 6 to a suitable source of electric current, through a voltage regulating device such as an adjustable transformer 22. The voltage supplied to the light cells may thereby be controlled and regulated in accordance with the transformer ratio as set by the pointer 23 on the dial- 24'.

in operation of the device, as thus assemble the light sensitive printing paper 26 may be i in cut sheets or from a continuous roll of the same over the apron 21 which leads from the front 8 up over the top of the belt I6, as the latter leaves the drive shaft and passes around the hollow cylinder i6. As the printing paper passes into the nip between the belt and the glass or plastic cylinder I6 the record sheet or negative 2B is ap- .plied to its upper or emulsion surface and both are carried between the cylinder l5 and belt i3 in firmly contacting superposed position around the cylindrical path of the outer surface of the cylinder, coming out from between the cylinder and belt as they part. The belt then passes over the roller i2, behind the lip 29- (of the top and back wall cover l) By such construction and operation of the printing device, the printing paper 2t, either in large quantities er as a continuous roll and susceptible to light, both as it is fed to the printer and as it cornes from the4 printer (after having been exposed to the required light for development through the negative) is not affected by extraneous direct or diffused light coming from the printing chamber into the dark room. This is a Very advantageous feature and while protection of light sensitive iilms from undesired exposure is a common object, it has not always been secured, especially in conjunction with mechanical printers to be operated at high speed and with a continuous strip of light sensitive In order to control the character and intensity of the exposure light, it is found to be advantageous to provide shields upon the walls of the light cells such as those shown in Fig. ri. Thus when a record sheet, positive or negative, characteristically presents a variation in its transparency to the exposure light, from one side to the other, this may be compensated for by applying to the outer surface of the tube a more or less opaque shield which is of appropriate shape to cut off a large proportion of the light from the cell in the more transparent portions but permitting the emission of progressively increasing proportions of light toward the more opaque-pon tions of the record sheet.

Thus, if light is to be reduced in the central areas, a diamond shaped shield 6i? may be employed. Conversely if the light emitted near the ends of the cell is to be less intense relative to the light emitted from the central portion ofthe iight cell, shields $3 may be provided therein which are broad at the ends and hence out off a considerable portion of the light evolved in these portions of the cell and which taper to a point or disappear at the center of the cell andthusperrnit all or nearly all of the light given o at the center of the cell to pass through and be projected through the negative and upon the light sensitive printing paper.

It may be found that one side of a record sheet is too transparent. In such cases, a shield @t may be applied which is broad at this end of the cell and hence cuts off a substantial proportion cf the light, but which tapers continuously to the other end of the cell where the light may be of the proper intensity and is accordingly all permitted to pass through and to be effective in the printing operation.

it is to be understood that while the shields as thus described may be opaque and thus prevent all light from the adjacent portions of the light cell from passing directly through them to the printing paper, they may be selectively absorptive and/or transmissive to certain wave lengths of light and thus act as lters rather than as opaque light shields and consequently regulate and control most accurately both the intensity and spectral quality of the effective exposure light employed.

By removing wing nuts 35 the parts 32, Sii and 3l may be removed and by then loosening one of the belt rollers, to slacken the belt, the cylinder iii may be removed through the left end wall 6 (Fig. 3)

From the foregoing it will be evident that the partition I8 divides the interior of the cylinder ES into two compartments including the lamp coml partment, the .partition extending into substantially light-tight relation'to the inner periphery of the cylinder and the ends of the lamp compartment being closed to prevent the escape of light. Thus by employing an opaquebelt which substantially covers the periphery of the cylinder throughout the lamp compartment, the escape of light is prevented. Consequently the printer may be operated in a darkroom without danger of fogging the sensitized sheets as they are fed to and from the printer.

The modified embodiment shown in Figs. 5, 6, 7 and 8 comprises a casing having a tcp el', a back 42, a sloping front 43, inner end walls lli and 615, outer end walls A6, a horizontal partition il extending between the inner end walls M and l5 and a front door et pivotally mounted on the inner end walls at 13B to swing from the full-line position shown in Figs. 5 and 6 tc the broken-line position shown in Fig. 6. As in the first embodiment the modification comprises a belt 5S trained over rollers Eily and around transparent cylinder 52, butY instead of having four rollers only three are provided. Mounted on the lower side of the horizontal partition Si are guide rolls 53 which engage the inner faces of the marginal flanges on the belt as in the iirst embodiment. The modification also has a stationary opaque partition 54 extending through the cylinder and mounted on stationary ends 55, the tition and ends having light-tight relation to the cylinder as by means of felt pads as in the first embodiment. In the modicaticn three lamps 'lll are provided instead of two. Instead of being mounted beyond the end of the transparent cylinder the motor 56 is mounted below the rear roller 5I between the inner end -walls and i5. The motor is connected to the rear roller 5l by means of gearing 51 located between the end walls 45 and 46. The circuits of the motor and lamps are controlled independentlyby means of four switches 58 and the voltage supplied to the lamps may be regulated by means of a variable resistance or a variable transformer 59. A light meter for measuring the density of negatives may be mounted on the casing as indicated at 'l I.

As indicated by the arrow in Fig. 6 the cylinder 52 rotates clockwise instead of counter-clockwise asin Figs. 1 to 3. Thus the record sheets are fed between the cylinder and belt at the top instead of the bottom, the horizontal surface 66 serving to guide the sheets to the cylinder'. At the bottom a stationary guide 6| is mounted on the end walls 44 and 45 just above the location where the belt leaves the cylinder to insure separation of the sheets from the cylinder at this location. Mounted on the pivotal support 49 for the door 46 is a pan 62 which in the closed position of the door guides the sheets to the bottom of the casing and in the open position of the door serves to catch the record sheets. If desired the bottom oi the casing may be iprovided with an opening so that, when the door is closed, sheets are discharged through the opening into a suitable receptacle.

While any suitable lamps may be employed in the three receptacles inside the cylinder 52, preferably the three types of lamps shown in Fig. 4 are employed in the three receptacles respectively. By turning the lamps so that the opaque tapered shields face the partition 54 the shields are rendered ineffective. To render one or more of the shields eective the lamps are rotated approximately 180 degrees so that the shields face the cylinder instead of the partition.

For the purpose of rotating the lamps without breaking the light-seal the lamps are connected with outside handles on knobs 63 through the medium ofa shaft 64, a curved arm 65 and a clamp 66 on the end of each lamp. The shaft 64 is journaled in the end walls 45 and 46 and the end light-seal 61 corresponding to 30 of Fig. 3. The curved arm 65 preferably has some exibility so that the shaft 64 need not be accurately aligned with the axis of the lamp. calibrations 68 may be provided on the outer wall 46 to indicate the position of the lamp inside the light-tight lamp compartment.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modications and equivalents which fall within the scope of the appended claims.

I claim:

1. Apparatus for printing light sensitive sheets from record sheets comprising rollers disposed at the corners of an intervening space, a hollow light-transmitting cylinder disposed in said space adjacent two of said rollers, and an endless belt trained around said rollers and looped into said space between said two rollers and around the cylinder in supporting relation to said cylinder, the diameter of the cylinder being greater than the distance between the two rollers and the 6 cylinder being free to be drawn into juxtaposition to the two rollers when the belt is taut, the belt having marginal flanges which straddle the cylinder to keep it centered on the belt.

2. Apparatus for printing light sensitive sheets from record sheets comprising rollers disposed at the corners of an intervening space, a hollow light-transmitting cylinder disposed in said space adjacent two of said rollers, and an endless belt trained around said rollers and looped into said space between said two rollers and around the cylinder in supporting relation to said. cylinder, the diameter of the cylinder being greater than the distance between the two rollers and the cylinder being free to be drawn into juxtaposition to the two rollers when the belt is taut, the belt having marginal flanges which straddle the cylinder to keep it centered on the belt, and guide rolls bearing on the inner faces of said flanges to keep the belt centered on the rollers.

3. Apparatus for printing light sensitive sheets, from record sheets, comprising a hollow lighttransmitting cylinder suspended by a loop of flexible belt, means for driving the belt to rotate the hollow cylinder and to convey the sheets and records between the belt and rotating cylinder, and anges on the longitudinal margins of the belt, on the inside thereof with respect to said loop and straddling the cylinder, whereby the hollow cylinder is retained in aligned position in the loop of the driven belt.

FRANCIS H. CARY.

REFERENCES CITED The following references are of record in the nie of this patent:

UNITED STATES PATENTS Number Name Date 847,567 Flicktner Mar. 19, 1907 1,197,399 Richards Sept. 5, 1916 1,360,717 Bossert Nov. 30, 1920 1,628,436 Segr-in May 10, 1927 1,636,680 Cannon July 26, 1927 1,919,275 Dunham July 25, 1933 2,041,478 Niederle May 19, 1936 2,220,526 Kluitman Nov. 5, 1940 2,297,573 MacDonald et al. Sept. 29, 1942 2,311,849 McDonald Feb. 23, 1943 2,313,632 Eggert et al Mar. 9, 1943 2,320,334 Bates June 1, 1943 2,346,988 Noel Apr. 18, 1944 2,351,339 Hruby June 13, 1944 2,357,541 Pfeil Sept. 5, 1944 2,406,702 Morreall Aug. 27, 1946 FOREIGN PATENTS Number Country Date 380,647 Great Britain Sept. 22, 1932 770,320 France June 25, 1934 OTHER REFERENCES Clerk (text), Photography, 566 pages, published by Sir Isaac Pitman and Sons, London (1930), pages 464, 465 especially cited.

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