US2312561A - Photographic enlarger - Google Patents

Description

March 2, 1943. 'A LEONARD 2,312,561

PHOTOGRAPHIC ENLARGER.

Filed Feb. 12, 1941 2 Sheets-Sheet l 2 INVENTOR ANTHON A. LEONARD ATTO RNEY5 March 2, 1943. A. A. LEONARD PHOTOGRAPHIC ENLARGER Filed Feb. 12, 1941 2 Sheets-Sheet 2 INVENTOR ANTHON A. LEONARD Patented Mar. 2, 1943 2,312,561 rno'rooasrmo ENLARGER Anthon A. Leonard, Glenside, Pa., assignor to De Jnr-Amsco Corporation, Shelton, Conn, a cor poration of New York Application February 12, 1941, Serial No. 378,494

9 Claims.

house for axial flow of air for cooling purposes,

and to provide inlet passages so located that the upward flow of air caused by the heated lamp house will also cool the condenser lenses. A further object is to provide an extra cooled jacket around the lamp house, so as to avoid danger of injury on contact with the same. Another object is to cool both the inner case and the exterior jacket, by means of appropriately divided air streams.

A further object is to provide a top assembly for the lamp house which will afford free discharge of air from both the jacket space and the interior of the lamp house, the air being discharged over a large area, while preventing passage of light out of the lamp house, and the settling of dust into the lamp house. Another object is to provide the top assembly with a maximum area for radiation of heat.

To the accomplishment of the foregoing, and such other objects as will hereinafter appear, my invention consists in the lamp house and condenser elements and their relation one to the other as hereinafter are more particularly described in the specification and sought to be defined in the claims. The specification is accompanied by drawings. in which:-

Fig. l is a perspective view of an enlarger embodying features of my invention;

, Fig. 2 is a partially sectioned elevation of the lamp house;

Fig. 3 is a partially sectioned plan view taken in the plane of the line 3-3 of Fig. 2;

Fig. 4 is a horizontal section taken in the plane of the line 4-4 of Fig. 2;

Fig. 5 is a transverse section showing a detail, and taken in the plane of the line 5-5 of Fig. 4;

Fig. 6 is a schematic sectional view through the lamp house explanatory of the flow of air through the same for cooling purposes; and

Fig 7 is a similar view explanatory of the manner in which light from the lamp house is baffled.

Referring to the drawings, and more particularly to Fig. 1, the enlarger comprises a base 52, an upright column 14 rigidly mounted on base i 2, a head generally designated i 6, and carried on a bracket i8 which is slidable on column M. The

head [6 comprises a lamp house 20 with a bellows 22 therebeneath. The negative may be placed in a negative stage 24, while a lens is mounted at 26. The lamp is energized through an electric supply cord 28, which passes downwardly through hollow column i4, and thence outwardly at 38 for connection to a household wiring outlet.

Referring now to Fig. 2, the lamp house con1- prises a cylindrical inner case 32 beneath which is carried a condenser housing or barrel 3 com taining the usual piano-convex condenser lenses 36. A lamp 38 is carried in a socket 4B surrounded by a frustro-conical light shield d2. A heat absorbiiig glass lid is disposed in the top of the lens housing, between the lam and the lenses 36.

The inner case 32 is imperiorate and is surrounded by an irnperiorate outer jacket 45 spaced therefrom. A highly perforate ventilator band 48 is disposed around and spaced from the lens housing 34. A multiple flanged cap assembly, generally designated as, is disposed at the top of the lamp house and is so arranged as to permit upward discharge oi air and radiation of heat while bafliing the escape of light and settling of dust.

The cooling action of the lamp houw is more clearly shown in Fig. 6, referring to which it will be seen that heating and consequent upward new of air in the lamp house causes intake of at 52 through the apertures in ventilator band it. The cool air flows upwardly along the lens hous= ing 34 and cools the same. The rising then divides, one art flowing inside the case 32, as is indicated by the arrows 5 3. This part is guided upwardly by an annular wall 56. The heated air then flows upwardly around the light baffle i2 and is discharged between upwardly flanged caps 58' and 60, as is indicated by arrow also between cap 60 and center cap ii, as is indicated by arrow 66.

Another component of the air entering the van" tilator band fiOWS upwardly through the jacket space between case and jacket air cools the inner case 32, and prevents heating of the outer jacket 58, so that the latter remains comparatively cool at all times. The air flowing upwardly through the jacket space is discharged between an outer flange 88 and a cap it, as is indicated by arrow i2, while another part is discharged between cap "iii and cap 53, as is indicated by arrow i i.

The action of the lamp house in preventing the escape of unwanted light will beclear from iiispection of Fig. l, in which it will be seen. that light ray I6 clearing baflle d2 is reflected back at I8. Light ray 80 clearing baiiie 50 encounters wall 32, and even if repeatedly reflected finally is stopped by perpendicular reflection at 82.

Even if it be assumed that every point on the true interior of the lamp house is a source of light, it will be found that any light rays passing outside the shield 42, such as the ray 8 3, will be trapped as indicated by the reflections 85, 80, and 90. Similarly, a light ray clearing the baiile 5%, such as the ray 92, will be bailied by reflections indicated at 90, 96, and 98.

Various other rays maybe drawn, but it will be found that the lamp house as here designed is light-tight, and this is an important advantage not only for general work, but also for threecolor work.

The constructional details of the lamp house may be described with reference to Figs. 3 through 5 of the drawings. The lamp house comprises a cylindrical sheet metal inner case 32 and an outer jacket 46 carried between an upper preferably die-cast member I and a lower preferably die-case member I02. The inner case 32 is secured to members I00 and I02, while the outer jacket 35 is merely carried therebetween. Specifically, inner case 32 has a number of studs I04 secured thereto by screws I06, and these studs pass upwardly through member I00. They also function to hold the upwardly flanged cap III in position, as by means of nuts I08 and I I0. The inner case 32 is secured to the lower member I02, as by means of screws I I2 (Figs. 4 and 5). These screws pass into thickened fins I M which replace some of a series of thinner radial fins lid, these fins all being die-cast integrally with lower member I02. In the present case there are eight flns, two of which are thickened. The fins project radially outward from the guide and bafile wall 56, and bear against the inside of case 32.

The bottom member I02 further includes an upwardly and downwardly extending light bame I I8 connected by a web I20 to upwardly extending flange I22 and downwardly extending flange I24. The outer jacket 46 is received within upwardly extending flange I22. The downwardly extending flange I24 is'connected by means of screws I26 to the upper edge of the ventilator band 08. The lower edge of this band is connected by means of thumb screws I30 to a die-cast generally square member I32 having an arm ISI which leads to the bracket I8 mentioned in connection with Fig. l. Member I32 is secured to another generally square member I36 by means of thumb screws I38, and the upper end of the bellows is connected at this point. The member I36 also serves to hold the condenser housing 3 3 in position, this resting against a ledge I40 on member I36.

It will be understood that the web I20 of member I02 is cut away to form large area ventilating passages, these being indicated at I62 in Fig. 4. Similarly, the web It in upper member I00 is cut away to form ample ventilating passages of similar character.

The upwardly flanged cap 58 rests on a raised annular surface I48 forming a part of the upper die-cast member I00. Caps 60 and 00 are disposed thereabove and are all secured in position by screws I50, these screws passing through suitable tubular spacers I52 and IS I. The lower ends of the screws are received in threaded, holes in the raised surface I48, two of these being indicated at ISI in Fig. 3.

This raised surface is cut away to form large aaiacei ventilator openings indicated at I56 in Fig. 3. The lamp socket d0 (Fig. 2) is secured at the center of this surface, together with the upper edge of light bafiie 82. The conductors from the lamp socket extend to a connector I60 (Fig. 4) which is mounted on cap 5d. A part of the flange of the next lower disc 60 is cut away at I02 to clear a passage for the male connector member I84 (Figs. 2 and 3) at the end of the electric supply cord 23.

It is believed that the construction, method of assembly, and operation of my improved lamp house, as well as the many advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described my invention in a preferred form, many changes and modifications may be made in the structure disclosed without departing from the spirit of the invention as sought to be deflned in the following claims.

I claim:

1. A top assembly for a vertically disposed cylindrical lamp house, said assembly comprising a series of circular upwardly flanged caps of progressively smaller diameter superposed in the order of decreasing diameter, said caps being annular and spaced at their inner and outer peripheries, each cap having a flat annular portion surrounded by an upwardly turned cylindrical portion, a topmost circular imperforate cap having a downwardly turned flange, and means including spacers to hold said caps in desired spaced superposed relation, the assembly affording ready egress of air, but bafiling the passage of light.

2. A top assembly for a vertically disposed cylindrical lamp house, said assembly comprising a lamp socket, a frustro-conical light shielc'. atsaid socket, and a series of circular upwardly flanged caps of progressively smaller diameter superposed in the order of decreasing diameter, said caps being annular and spaced at their inner and outer peripheries, each cap having a flat annular portion surrounded by an upwardly turned cylindrical portion, a topmost circular imperforate cap having a downwardly turned flange, and means including spacers to hold said caps in desired spaced superposed relation, the assembly aflording ready egress of air, but baflling the passage of light, the resulting discharge passagesbetween the upwardly turned flanges of the caps occupying a large portion of the area of the top of the lamp house, and the multiple flanges providing a substantial surface area for heat radiation.

3. A lamp house for an enlarger, said house comprising a cylindrical inner case, a cylindrical outer jacket surrounding but spaced from said case, a condenser housing beneath said case, a perforate ventilator band surrounding but spaced from said condenser housing, passages between the Ventilator band, the case, and the jacket space, for dividing air flowing upwardly \from the ventilator band past the condenser housing and for permitting part of said air to be drawn into the lamp case for upward flow through the case, and for permitting the remainder of said air to be drawn upwardly through the jacket space between the case and jacket, and multiple flanged caps supported in spaced telescoping relationto each other at the top of said lamp house for affording free upward discharge of air from both the case and, jacket while preventing passage of light.

4. A lamp house comprising a cylindrical case, a condenser housing beneath said case. a ventilator band surrounding but spaced from said condenser housing, and a cast metal member for holding said parts in assembled relation, said member having a guide wall spaced inwardly of said case, fins extending radially from said guide wall to said case, and an external flange extending downwardly for receiving said ventilator band.

5. A lamp house comprising a cylindrical case, a condenser housing beneath said case, a ventilator band surrounding but spaced from said condenser housing, and a cast metal member for holding said parts in assembled relation, said member having a guide wall spaced inwardly of said case, fins extending radially from said guide wall to said case, a light baflie between said case and lens housing, and an external flange extending downwardly for receiving said ventilator band.

6. A lamp house comprising a cylindrical case, a cylindrical jacket surrounding but spaced from said case, a condenser housing beneath said case, and a cast metal member for holding said parts in assembled relation, said member having a guide wall spaced inwardly of said case, fins extending radially from said guide wall to said case, and an external flange extending upwardly for receiving said jacket.

'7. A lamp house comprising a cylindrical case, a cylindrical jacket surrounding but spaced from said case, a condenser housing beneath said case,

and a cast metal member for holding said parts in assembled relation, said member having a guide wall spaced inwardly of said case, fins extending radially from said guide wall to said case, a light baiile between said case and lens housing, and an external flange extending upwardly for receiving said jacket.

8. A lamp house comprising a cylindrical case, a cylindrical jacket surrounding but spaced from said case, a condenser housing beneath said case, a ventilator band surrounding but spaced from said condenser housing, and a cast metal member for holding said parts in assembled relation, said member having means to hold said case, a light bailie between saidcase and lens housing, and external flanges extending upwardly for receiving said jacket and downwardly for receiving said ventilator band.

9. A lamp house comprising a cylindrical case, a cylindrical jacket surrounding but spaced from said case, a condenser housing beneath said case, a ventilator band surrounding but spaced from said condenser housing, and a cast metal member for holding said parts in assembled relation, said member having a guide wall spaced inwardly of said case, fins extending radially from said guide wall to said case, and external flanges extending upwardly for receiving said jacket and downwardly for receiving said ventilator band.

ANTHON A. LEONARD.

Images