US1804771A - Adjustable light source for photographic printing machines - Google Patents

Description

May 12, 1931. I s, HOPKINS 1,804Q771 ADJUSTABLE LIGHT SOURCE FOR PHOTOGRAPHIC PRINTING MACHINES Filed Oct. 22. 1929 Patented May 12, 1931 UNITED STATES PATENT OFFICE ROY S. HOPKINS, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORIfQRATION OF NEW YORK ADJUSTABLE LIGHT SOURCE PHOTQGRAPHIC PRINTING MACHINES Application filed Qctober 22, 1929. Serial No. 401,407.

This invention relates to photography, and more particularly to a source of light for photographic printing machines.

It has for its object to provide a source of light from which light rays of different known intensities may be obtained with minimum effort on the part of an operator. Another object is to provide a source of light having a plurality of light intensities which may be used one at a time. Another object of my invention is to provide a multiple light source which is adjustable to bring a single source of light into operative position at a time and to permit other sources of light of different intensities to be operatively positioned for printing. Another object of my invention is to provide a source of light ncluding a movable base having a plurality of lamp receptacles arranged to accurately position the filaments of each-lamp in a print ing position. Still another obj-ect is to pro vide a pivoted base having-a plurality of lamp sockets, each socket being adapted to make a circuit when swung into an operative printing posit-ion. Still another object is to provide a source oflight havinga plurality of sockets movably mounted and means for automatically making a circuit through any one socket positioned for printing. I

Other objects will appearfrom the following specifi'catiomthe novel features being pointed-out in the claims at the end thereof.

Coming now to the drawings, wherein like characters denote like parts throughout 1 F ig. 1 is a diagrammatic side elevation of V a printer having a portion of its side broken away, showing in elevation a detail of my invention. 7 t

Fig. 2- is a front elevation of the lamp bracket supporting a. plurality of lamp sockets. I 1 Fig. 3 isa front elevation of the contact block.

'F 1 is a detail in section of a spr ng contact and the contact block;

modification of a lamp bracket supporting a embodiment of my invention.

My present invention is particularly adapted for use in a printing machine of the type shown in my copending application, Serial No. 158,882, filed December 10, 1926 although obviously it may be used with other type of machines. For the operation of the printer parts, reference may be had to the showing in my copending application.

As shown in Fig. 1, a printer 1, is provided with a source of light comprising a plurality of lamps 2, which are supported by a bracket 3. The bracket 3 also supports a block 41 which carries a plurality of contact points with which the spring contact 6 completes a circuit. The spring contact 6 is supported. by an insulated block 7, which is mounted with bracket 3 on the bolt 8, said bolt acting as a pivot for the bracket. A reflector 9 is provided to direct the light rays through the aperture 10 to the mirror 11 which directs said light rays to the printing panel of the printer 1, as fully described in my copending application above referred to.

The bracket 3 as best shown in Fig. 2. comprises a base 12. pivoted on the bolt- 8. and a plurality of lamp sockets for lamps of different intensities. For example one socket also supports a contact block 4 carrying a plurality of contact buttons 18 one connected to each lamp socket as by wires 19 with wires QO-leading to a'source of power 21, as shown in Fig. 5.

The contact button 18-and the contact point 22'of spring contact 6 may be of any desired form, but the nipple and dimple types as shown in Fig. 3 and Fig. 4 are preferred. \Vhen contact point 22enters a dimple 18 it both makes a circuit and acts as a snap-latch for holding bracket 3 in a set position.

A modification of bracket 3'is shown in Fig. 6, comprising a base 23, pivotally mounted at 17. supportinga plurality of lamp sockets 24. said lamp sockets being adjustably mounted as by thumb screw 25, said adjustment, pro

' bracket supporting vsaid lamps and insulate, ing block.

printing machine due to the density oithe individual negatives. To do this, by the present method, he must reduce the current to the lamp by a rheostat, which method has a number of disadvantages. First, the range of light intensities can not always be taken care of by'a rheostat. Second, a change in the rheostat does not produce an lnstantaneous change in lamp brilliance. Third, a color change in theillumination takes place in altering lamp intensities through a wide range by. a rheostat.

By the method disclosed in my invention, however, these ditiiculties are avoided as the operator is merely required to change from one lamp to another by swinging the pivotally mounted bracket for major changes in light intensity, and the operator may use a rheostat for minor changes in light intensity. Thus much unnecessary heat is avoided, the light can be more accurately controlled, and much less current is consumed,

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a photographic printing machine the combination with a printing panel, of a source v of light for said printing panel comprising; a plurality of lamps and a pivotal base sup porting said lamps,

2.;111 a photographic printing machine the combinatlon with a printing panel," of. an adjustable source of 7 light for said-printing j panel comprismg a plural ty of-lamps, eachlam) having a different intensitv and a pivotally mounted bracket support-ing said lamps.

3. In a the combination with-a printing panel, of

5 an adjustable source of licht'for said panel comprising a plurality of lamps, each lamp having a different intensity, an insulating blockcarrying a plurality oi contact points,

and a pivotally mounted bracket supporting. said lamps andinsulating block; I

4. In aphotographic printing machine the combination with a printing panel, of an adjustablesource of light for said panel comprising a plurality of lamps of diiierent intensities, an insulating block carrying a plurality-jot contact points,each point connected to the corresponding lamp socket, a spring contact to complete any one ol the plurality of lamp circuits,-and-a pivotally mounted 5. In a photographic printing machine the photographic printing machine, I

combination with a printing panel, of an adjustable source oflight for said panel com- 7 prising a plurality of lamps of different intensities, an insulating block of fibrous mate rial carrying a plurality of contact polnts, each point connected to the correspondlng lamp socket, a spring contact, completing any one of the plurality of lamp circuits, mounted on an insulated ,base, a pivotal bracket supporting said lamps and insulating contact point block and-a pivot support-: ing said bracket and insulated spring contact base.v I

6. In a photographic printing machine of the type utilizing a concentrated light source, the combination with a printing panel of a pivotally mounted lamp bracket supporting for sail bracket, an insulating otal support block supporting a series of contact points carried by the bracket, each contact point being connected to a lamp,,and means to simul taneously bring one point at a time into operative position with a spring contact, and the corresponding lamp-into operative position for illuminating the printing panel, said spring contact being adapted to hold the bracket in said position;

7 In a photographic printing machine the combination with a printing panel a source of light for said printing-panel comprising a plurality of. adjustable lamp sockets and pivotal base supporting said lamps' 8. In a photagraphio printing machine the combination with a printing panel, an adustable source of li ht for said printing panel comprising a plurality of lamps,r.each lamp having a different intensity,a pluralityof radially adjustable lamp sockets supporting said lamps, and a pivotal bracket supporting 'said'bracket. I a

* 9." In a photographic printingmachine the combination with a printing panel of an ad 'justablesource of light "for said panel comprising-a plurality or lamps, each lamp having a different intensity, a 'pluralityofradially 'adjustablelamp sockets supporting said lamps,2an insulating block carryinga plu-- rality of contact points, and a pivotal bracket" supporting said bracket and insulating block,

10. In a photographic printing machine the combination with a printing panel, of an i adjustable: source oflightfor said panel comprising a plurality of lamps of difierent intensities, a plurality of radiallyadjustable lamp sockets supporting said lamps,a plurality of thumb screws controlling the adjustment of said lamp sockets, an insulating block carrymg a plurality of contact points, each,point connected to the corresponding lamp socket, a spring contacttoicomplete any one of the plurality of lamp circuits, and a pivotal bracket supporting said lamps and insulating block.

11. In a photographic printing machine of the type utilizing a concentrated light source, the combination with a printing panel of a pivotally mounted lamp bracket supporting a plurality of radially adjustable lamp sockets carrying a plurality of concentrated filament lamps, each lamp having a different intensity, a pivotal support for said bracket, a series of thumb screws carried by the bracket, each screw controlling the adjustment of the corresponding socket to its relation thereto, an insulating block supporting a series of con tact points carried by the bracket, each contact point connected to a lamp socket and means to simultaneously bring one point at a time into operative position with a spring contact and its corresponding lamp into operative position for illuminating the printing panel, said spring contact being adapted to hold the bracket in said position.

12. In a photographic printing machine the combination with a printing panel, of a source of light for said panel including a movably mounted lamp bracket, a plurality of lamps carried thereby, a plurality of incomplete circuits including the lamps, and means tending to retain the bracket in a set position, said means also forming a switch for completting an incomplete circuit to a lamp.

13. In a photographic printing machine the combination with a printing panel, of a source of light for said panel including a movably mounted lamp bracket, a plurality of lamps carried thereby, a plurality of incom-' plete circuits including the lamps, and a spring arm adapted to resiliently engage Said bracket for locating the bracket and comtileting one lamp circuit.

14. In a photographic printing machine the combination with a printing panel, of a source of light for said panel including a movably mounted lamp bracket, a plurality of lamps carried thereby, a plurality of incomplete circuits including the lamps and means tor completing one circuit at a time including a pair oi cooperating contacts. one adapted to enter into the other, said contacts serving as a sun p latch tending to hold the bracket in a set position.

Signed at Rochester, New York, this 16th day of October, 1929.

m ROY S. HOPKINS.

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