US2266908A - Negative carrier structure for photographic enlargers - Google Patents

Description

E. C. ROGERS Dec. 23, 1941,

NEGATIVE CARRIER STRUQTURE F'OR PHOTOGRAPHIC ENLARGERS Filed Feb. 17, 1940 2 Sheets-Sheet 1 fzmoazaPaazag, .2?

ATTORNEYS Dec. 23, 1941 E. c. ROGERS I NEGATIVE CARRIER 2,266,908 STRUCTURE FOR PHOTOGRAPHIC ENLARGERS Filed Feb. 17, 1940 INVENTOR. fix 0406. P062195, BY

. ATTORNEYS.

Patented Dec. 23, 1941 UNITED STATES PATENT OFFICE NEGATIVE CARRIER STRUCTURE FOR PHOTOGRAPHIC ENLARGERS 16 Claims.

It is the object of my invention to improve the construction of photographic enlargers. Particularly, it is my object to improve the negative carrier and its associated structure in an enlarger of the type shown in my co-pending application Serial No. 277,886, filed June 7, 1939; to improve the convenience with which the negatives of strips or rolls of film may be enlarged, and at the same time to provide for the enlargement of negatives which are on individual pieces of film. These individual negatives are usually cut from a strip or roll, and are conveniently referred to as cutfilms.

The accompanying drawings illustrate my invention: Fig. 1 is a side elevation of an enlarger, with parts shown in section; Fig. 2 is a front elevation of the parts of the enlarger of Fig. 1 adjacent the negative carrier; Fig. 3 is a vertical section taken on the line 3-3 of Fig. 1 and showing generally the same parts as Fig. 2, on an enlarged scale; Fig. 4 is a horizontal section taken on the line 44 of Fig. 3; Fig. 5 is a side elevation of the structure of Fig. 3; Fig. 6 is a vertical section taken on the line 6--6 of Fig. 3; Fig. 7 is an exploded view of a negative carrier in its arrangement for use with a cut film; Fig. 8 is an exploded view of a negative carrier in its arrangement for use with strip film carrying negatives of relatively small size; and Fig. 9 is an exploded view showing how a pair of glass plates may be used as a negative carrier in my enlarger.

The enlarger shown is Suitably supported by means including an arm 12.. The end of the arm I2 is provided with a housing I5, which is conveniently part of the same casting with the arm I2. This housing I5 is a shell which is open at both top and bottom, and tapers downwardly. Near its lower end, the housing I5 is provided with a transverse slot [6 for receiving a negative carrier. Just above the transverse slot IS, the housing [5 is preferably provided with an inwardly extending flange 18 on which a suitable condensing lens l9, shown as a plano-convex lens, may rest. I consider this condensing lens very desirable; but it is not fundamentally essential.

The upper end of the housing I5 is provided with a bell enlargement 20 for receiving the lower end of a lamp-housing 2| which carries a lamp socket in which a suitable depending lamp bulb 23 is mounted. The upper end of the bulbhousing 2| is provided with a central opening for a lamp cord (not shown) which supplies current to the lamp bulb 23, and with ventilating openings 25 to permit the outflow of air that is heated by that lamp bulb 23.

' Below the transverse slot l 6 which receives the threads 34.

. may be mounted inside of the sleeve.

negative carrier, the housing [5 is provided with a flat lower end 30. A barrel 33 is fastened to that lower end of the housing 15, which barrel is provided, at least at its lower end, with internal An externally threaded sleeve 35 may be screwed into the internally threaded barrel 33, with either end of the sleeve 35 uppermost. The sleeve 35 is provided at both ends with a pair of threaded longitudinally extending holes 36, conveniently near the opposite ends of a diameter, for receiving threaded pins 31 to provide a convenient finger hold for adjusting the sleeve 35 in the barrel 33; and th pins 31 are put in the holes 36 in whichever end of the sleeve 35 is to be downward.

One end of the sleeve 35 is provided with an inwardly extending flange 38, in which an objective lens 39 of long focal length may be mounted, with that lens projecting below the flange 38 when the flange 38 is at the bottom end of th sleeve. If an objective lens of short focal length is desired, however, the sleeve 35 may be turned end for end, so that the flange 38 is at its upper end, and a short-focus lens (not shown) In either case, the objective lens is desirably provided with an adjustable diaphragm, adjustable by the usual circumferentially movable knurled collar 43 by which the size of its light-transmitting opening may be adjusted, in known manner.

The slot 16 for receiving a negative carrier extends through the front wall 45 and through all but a small section at the rear of each of the side walls 46 of the housing l5. Below the slot I6, each side-wall 46 carries on its outer surface a guide 41 for a negative-plate (to be described later). Such guides 41 extend upwardly from the portions of the side-walls 46 below the slot l5 and project a short distance above the lower surface of the slot IS. The portions of such guides 41 which are above such lower surfaces of the slot l6 have inner surfaces 'alined with the outer surfaces of the side-walls 45; so that the lower surface of the slot [6 is flat over the entire width of the enlarger casing between the walls 46, with those guide standing above such lower surface at the side edges thereof. Each side wall 46, below the guides 41, is provided with a threaded hole to receive the clamp screw 48 of a guide finger 49 which is slotted for adjustment toward and away from the inner wall of the slot IS. The two guide fingers 49 extend upwardly well past the lower surface of the slot l6 and are adapted to be engaged by the rearward edge of a strip film El held by a negative carrier in the slot 16.

The negative carrier to be received in the slot l and particularly adapted for use with negatives on a strip of film comprises a pair of plates 65 and 52.

The plate 66, adapted in this use to be the lower or the two plates and to underlie the negative so that it forms a negative-support is a flat plate with a central film-masking opening, and is adapted to lie on the lower surface of the slot it between the guides 47. Its thickness is slightly greater than the height of the guides 47 above such lower surface, so that the plane of its upper surfac is wholly unobstructed. The negativesupporting plate 50 is normally stationary in use, but is made removable for interchange with others which have different film-masking openings. As will be seen in Fig. 8, the plate 65 is generally rectangular in shape, with a forwardly extending curved portion I5 and a rearwardly extending portion 7 l.

The plate 52 of the negative carrier, adapted in this use with strip film to be the upper plate and to overlie the film, has a central flat section which is of the same size as the plate 60, and

at its side and front edges is bent upwardly to form upstanding walls higher than the opening of the slot it, so that they overlap the walls of the housing I5 above such slot I6. From the upper edges of such upstanding walls at the side edges, the material of the plate 52 extends outwardly above and past the guide fingers 49, then downwardly to the plane or the central section of the plate 52, and then outwardly to form lifting flanges 5 The plate 52 thus has a central section, witha downwardly open channel 63 secured to each of its side edges and with a flange 64 extending laterally from the channel. The upstanding walls at the sides and front of the central section serve to close the upper portion of the slot It at its open sides and front to prevent the escape of light. Each pair of plates 60 and 62 are provided with central openings of a size adapted to mask a negative of one particular size. The plates are desirably provided in sets of several pairs of plates 56 and 52, with the different pairs provided respectively with central openings for different standard sizes of negatives which it may be desired to enlarge.

The side walls of the upper plate 62 not only close the opensides of the slot it, but also serve to locate such plate 52 laterally in proper position in the slot and in relation to the lower plate 55, the lower plate 55 being positioned by the guides 41. Both plates are further located, by engagement at their rear edges with the inner wall of the slot it. a film between them and against the lower surface of the slot 15 by springs 53, respectively mounted on the side walls 45 of the housing I5 just above the slot [5, which press downwardly on the upper faces of the channels 63.

Adjacent to the rear Wall of the enlarger casing [5 and behind the slot Hi there is a shaft 50 extending transversely through the casing I5. At each end of this shaft to there is a lifting arm 5! which is fixed to the shaft 55 and extends forward therefrom in position to lie beneath the flange 51] of a negative carrier plate 62. An operating arm 52 extends upwardly from at least one, and desirably from both, ends of the shaft 50, and is also fixed on the shaft 55, so that operation of an operating arm 52 will cause both lifting arms 5! to engage the under surfaces of the flanges 5'5 and lift the plate "52 away from its The plates are held against engagement with the film 6|, to permit any desired manipulation of such film 6 I.

The movement of the arms 52 is desirably limited. For this purpose, each side wall of the housing l5, just above the shaft 50, carries a lug 55 extending outwardly to the inner edge of its associated arm 52, and such lug 55 has spaced extensions 56 at its end, which lie in the path of the arm 52 to limit its movement. The lugs 55 may also serve to support the springs 53 which press downwardly against the negative carrier plates. To this end, a second lug 5? lies beneath each of the lugs 55 and is spaced slightly therefrom. The springs 53 are bent to form a pair of spaced shoulders 58 to engage the edges of the lug 55, and between those shoulders 58 the spring is of irregular configuration, as by having a downward oifset 59; so that the spring may be pressed into the slot between the two lugs, and

will be held firmly therebetween by the springpressure of the shoulders 58 against the lug 55, and of the offset 59 against the lug 51. The presence of the operating arm 52 at the outer end of the lugs 55 and 51 prevents the spring from slipping outwardly from its position between the lugs 55 and 51.

In the operation of this structure with the negative holder described, one of the operating arms 52 is pressed rearwardly to cause both lifting arms 5| to lift against the flanges 54 of the upper plate 62 of the negative carrier, to lift the u per plate 62 against the pressure of the springs 53, to the position shown in Fig. 6. The strip film 6! is then inserted from the front, and is moved rearward until it engages the two guide fingers 49, which are adjusted to guide the film 6| to a position in which the center line of its negatives will be alined with the center of the openings in the negative carrier plates 65 and 62. With the plates thus separated, the strip film 6| may next be moved lengthwise to bring the desired negative into alinement with the openings of the negative carrier. The arm 52 is then released, and the springs 53 press the upper plate 62 downwardly against the upper surface of the film 6!, to hold such film 5| flat and in proper position for focusing and printing. When suitable focusing and printing operations have been performed with the selected negative, another negative on the same strip of film may be moved into position for printing by again pressing an operating arm 52 rearwardly to separate the plates to permit such him to be moved longitudinally to bring such other negativeinto registry with the openings in the negative carrier plates. The handle 52 is then released, and the second selected negative is ready for printing.

When it is desired "to enlarge a cut-film negative, the arrangement of parts shown in Fig. 7 is used. The negative '13 to be enlarged is placed on the upper surface of the central section of a plate 62 which has an opening of the size desired forsu'ch negative 13. A plate 60 having a similarly sized opening is laid on top of the film l3, and by'i-tswe'ight holds the negative 7'3 in the desired position. A third ,plate 50, with an opening of the same or a larger size "than that of the plates 55 and 62 selected for holding the negative '13, is placed in d e enlarger between the guides 47, so that a surface 'is provided by the upper surface of such plate 630" above the upper ends of the guides 41. The assembled plates .65 and '52 with the negative 73 then inserted in the slot 1 6 of the enlarger on top of the plate 60, and s held down against the plate 5i) by the springs 53 so that the negative 13 is held in proper position normal to the axis of the enlarger. Because the central section of the plate 62 is of the same size as the plate 60, such plate 60 has a fairly accurate fit between the upstanding Walls of the plate 62 and is thus held from lateral movement except in a rearward direction. When the combined plates 60 and 62 are inserted in the enlarger, the shoulders at the sides of the rearward extensions H of the plates 60 and 62 engage the rear wall of the slot l6, so that the plate 60 is then held from lateral movement in any direction.

If desired, my enlarger may also be used with a negative carrier such as that shown in Fig. 9. This negative carrier consists of two plates of glass 15 and 16. The lower plate 15 is of the same size and shape as the rectangular portion of a plate 60 so that it fits between the guides 4'1 and against the short portions 45' of the side Walls 45 at the rear of the slot I6. The upper glass plate I6 is desirably of the same length as the overall length of a plate 62 so that its ends will overlie the lifting arms During the use of this glass negative carrier, the guide fingers 49 are adjusted to their extreme rearward position, so they will not interfere with the glass plate 16. If desired, an upper plate 62 of the form of negative carrier shown in Fig. 8 and having an opening of a suitable size may be inserted on top of such glass plate "I6, so that the side-walls of such plate 62 will close the slot [6. The plate 62 may also serve as a mask, but desirably has a relatively large opening, and any desired masking is obtained by the use of a mask applied to the upper surface of the glass plate 16.

The operation of the glass plate l5-'l6 negative carrier for the enlargement of negatives from a film strip will be substantially the same as with the use of the plates 60 and 62 in the arrangement of Fig. 8 and as shown in Fig. 3, for the lifting fingers 5| will underlie the upper glass plate 16 so that that glass plate may be lifted away from the lower glass plate 15 by pressing rearwardly on one or the other of the operating arms 52.

I claim as my invention:

1. In a photographic enlarger, walls forming I a slot for the reception of a negative carrier having separable upper and lower plates, one of said plates having extensions projecting outwardly beyond opposite ones of said walls, a pivotally mounted arm adjacent each of said opposite walls on axes parallel with the plane of said extended plate with the free ends of said arms respectively in position to engage said plate extensions, said arms being interconnected for simultaneous operation, and an operating member for said arms to move them to separate the extended plate from its associated plate.

2. In a photographic enlarger, walls forming a slot for the reception of a negative carrier having separable upper and lower plates, one of said plates having extensions projecting outwardly beyond opposite ones of said walls, a pivotally mounted arm adjacent each of said opposite walls on axes parallel with the plane of said extended plate with the free ends of said arms respectively in position to engage said plate extensions, said arms being interconnected for simultaneous operation, an operating member for said arms to move them to separate the extended plate from its associated plate, and spring-means on said enlarger acting on said plates oppositely to the separation action of said arms.

3. In a photographic enlarger, walls forming a slot for the reception of a negative carrier having separable upper and lower plates, one of said plates having extensions projecting outwardly beyond opposite ones of said walls, said extended plate being offset away from the associated plate adjacent each of said opposite walls, a pivotally mounted arm adjacent each of said opposite walls on axes parallel with the plane of said extended plate with the free ends of said arms respectively in position to engage said plate extensions, said arms being interconnected for simultaneous operations, an operating member for said arms to move them to separate the extended plate from its associated plate, and adjustable guide fingers mounted adjacent to said opposite walls and extending across the plane of separation of said plates and into the clearance space provided by said ofiset.

4. A photographic enlarger comprising a housing having walls forming a slot for the reception of a negative carrier, a negative-carrier plate adapted to be received in said slot, a second negative-carrier plate adapted to lie against said first plate and having side walls extending away from the plane of separation of said plates and slidably engaging the side of the enlarger to position said side-walled plate in the enlarger, said enlarger sides being parallel, oppositely and outwardly extending flanges on said side walls, and means on said enlarger for engaging said flanges and operable to separate said plates.

5. A photographic enlarger comprising a housing having walls forming a slot for the reception of a negative holder, a negative holder including a movable plate which has a face adapted to engage a negative, vertical side faces on said enlarger adjacent said slot, said slot being of sufiicient Width to permit considerable movement of said plate while in position in the slot, side walls on said movable plate extending across the clearance space in said slot and slidably engaging said side faces to close said space against escape of light and to position said movable plate, said movable plate being spring-pressed to urge said face toward the face of a normally stationary negative-support to hold a negative therebetween, means for moving said plate away from said negative support, and an adjustable negative guide at the plane of separation between said plate and negative-support.

6. A photographic enlarger comprising a housing having walls forming a slot for the reception of a negative carrier, a negative-carrier plate adapted to be received in said slot, a second negative-carrier plate adapted to lie against said first plate, oppositely and outwardly extending stretches on said second plate which are ofiset from said plane of plate separation, and negative guides carried by the enlarger and adjustable in said plane of separation and which extend across said plane of plate separation into the clearance space provided by the offsetting of said stretches.

7. A negative carrier for a photographic enlarger which has walls cut through by a slot for the reception of the negative carrier, comprising a pair of plates of materially less thickness than the width of said slot, one of said plates having side walls positioned to lie against the enlarger walls to close the slot against escape of light and to permit plate separation.

8. In a photographic enlarger, wall forming a slot for the reception of a negative carrierhaving separable upper and lower plates, said upper plate extending beyond the enlarger walls, means mounted on the enlarger having portions arrangedto engage the extending portions of the upper plate for lifting the upper plate while it is in position in the enlarger, a pair of lugs extending laterally from opposite side walls oi? the enlarger housing, each pair of lugs being spaced apart to form agroove therebetween, a sprin supported in each oi'said grooves and arranged to press the negative-carrier plates together, said lifting means having also a portion lying across the ends of the lugs of each pair in position to prevent said springs from moving outwardly out of engagement with said lugs.

9. The combination defined in claim 8, with the addition that the portions of said litfing means which lie at the ends of the lugs are movable, said lugs being adapted to interengage said lifting means portions to limit the movement thereof.

10. The combination defined in claim 8, with the addition that the portions of said lifting means which lie at the ends of the lugs are movable, and stop means limiting the movement of said portions.

ll. In a photographic enlarger, walls forming a slot for the reception of a negative carrier having separable upper and lower plates, means for lifting the upper plate while it is in position in the enlarger, said lifting means comprising lifting fingers adapted to interengage one of said negative-carrier plates on opposite sides of the exposing opening therein and pivotally mounted on a common axis, and means for simultaneously moving said fingers to move the interengaged plate away from its associated plate to permit the movement of a negative therebetween.

12. In combination, a photographic enlarger having walls cut to form a slot for the reception of a negative carrier, a negative carrier therefor, said negative carrier comprising a pair of plates, the first ofsaid plates having. upstanding walls to slidably engage the walls of the enlarger adjacent said slot to position said plate in the enlarger, the second plate being adapted to be received within andpositioned by said upstanding Walls whereby the assembly is adapted to receive a cut negative between the plates and to be movable as a unit, and means on the enlarger for independently positioning said second plate in position on the opposite side of said first plate from its upstanding- Walls, whereby the plane of separation between the plates is unobstructed for receiving a. strip negative.

13. In combination, a photographic enlarger, a negative carrier therefor, said negative carrier comprising a pair of plates, the first of said plates having means co-operating with parts of the enlarger for positioning it therein, said means also being adapted to position the second of said plates with respect to said first plate when the second plate is on one side of the first plate, and independent means on the enlarger for positioning the second plate when it is used on the other side of the first plate.

14. The combination defined in claim 12 with the addition of a third plate adapted to be received by said independent positioning means and to support said walled plate.

15. A photographic enlarger, comprising a housing having a slot for the reception of a negative carrier, a negative carrier including a pair of plates one of which is adapted to lie against one side surface of said slot, guide means to position said plate in the slot, the second of said plates being adapted to lie against said first plate and to be spaced from the opposite side surface of said slot, walls on said second plate adapted to slidably engage the casing walls adjacent to said opposite side surface of said slot to position the plate with respect thereto and to close the slotagainst the escape of light While permitting separation of said plates, said plates having alined negative-exposing openings therethrough.

16. A photographic enlarger as defined in claim 15 with the addition of a third plate adapted to be received between said walls and to be positioned thereby on said second plate for holding a cut negative thereon, said third plate also having a negative-exposing opening.

ELWOOD C. ROGERS.

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