US2287328A - Studio spot lamp - Google Patents

Description

June 23.11942. J, Q ROSE f 2,287,328

STUDIO sPoT LAMP Filed Feb. s, 1941 2 sheets-sheet 1 lamentan Jess 6R05?.

a/-Mpw Jun@ 23,1942. J, ROSE 7 2,287,328

STUDIO SPOT LAMP Filed Feb. 5, 1941 2 Sheets-Sheet 2 [2z L'ez Zar. E Jes; Cl Rose.

Patented June 23, 1942 UNITED STATES ortica STUDIO SPOT LAMP Application February s, 194i, serial N. 377,154 4 claims. (ol. 24o-47) This invention relates generally to studio spot lamps such as are used in motion picture studios for illumination of sets. A

Studio spot lamps are ordinarily designed with ventilation openings arranged to permit circulation of air through the lamp casing for cooling purposes. It is always an object to arrange these openings in such a Way that air circulation and consequent cooling will be ample.

Lamps of this type are also sometimes designed with the purpose in View of permitting use under rainfall conditions (either natural or artificial) without liability of water getting inside the casing through these ventilation openings. A still further design requirement is the provision of light trap arrangements at ventilation openings to prevent escape of light through the lamp casing, since stray light on a set is ar detriment to good. photography.

The object of the present invention is to provide an improved and simplified studio lamp construction designed for maximum air circulation, for eifective exclusion of water, and for eiective trapping of light at all openings.

The present invention will best be understood without preliminary discussion by referring at once to the following detailed description of one illustrative embodiment, reference for this purpose being had to the accompanying drawings, in which:

Fig. 1 is a transverse'vertical section taken on line l-l of Fig. 2;

Fig. 2 is a section taken on broken 'lines 2-2 f Fig. l;

Fig. 3 is a top plan View of the lamp;

Fig. 4 is a detail section 'taken on line 4 4 of Fig. l; and

Fig. 5 is an enlarged section taken on line 5-5 of Fi-g. 2,

The lamp of the present invention has a cylindric casing ill, extending between circular front and rear end frame members II and I2, respectively, and has at the bottom a rectangular housstructure or box i3. In the present illustrative embodiment, the end frame members Il and I?. are sheet metal spinnings, each having an inwardly turned annular flange I6 defining a circular opening for a hinged door. A rear door 'i is receivable inside the rear door opening, being hinged at I8 on rear end frame I2. A front door I9 is receivable inside the front door opening, being hinged at 2li on front end frame li. These doors may be of any suitable construction, not necessary here to describe in detail. However, it may be mentioned that the rear door is shown as provided with a manual knob 22, and will preferably be provided with any suitable type of latch mechanism, not here detailed. And front door I9 is equipped with the usual lens 23, preferably and here shown as the Fresnel type, and may have a somewhat forwardly projecting annular ange part 24 equipped with diffuser brackets r25.

End frame members I I and I2 are formed with .iarginal inwardly Yturned flanges 2t within and to which certainparts'of the cylindric side wall construction are received' and secured.

The rectangular bottom structure I3 of the lamp includes flanged endframe extensions 2l secured to the bottoms vof members II and I2, and integral side and 'bottom wall members 32 and' which extend, between end frame extensionsZl and are received inside and secured lto theanges' 28 of the latter. As 'here illus- 'tra-tively shown, the inner edges of bottom members 3S define an air inlet aperture in which is received a light-trap structure lit, the latter comprising vertical side walls lli secured to the edges of bottom members 33, and transverse chevron-shaped light baiiles ft2 extending between walls ai. The bailies G2 are relatively closely spaced, so as to prevent any light escaping downwardly through the bottom of the lamp, while-at the same time aiiording passageways for free circulation of air into the interior of Ythe lamp.

The cylindric side wall Il! of the lamp comprises an outer series of inwardly facing circumferential channels 5 and anvinner series of outwardly facing circumferential channels 66, the channels of both series-being spaced longitudinally of the lamp by a spacing interval which is somewhat less vthan `the width of a channel. The inwardly facing channels i5 comprise webs il and inwardly extending flanges 48, and the outwardly facing channels 46 comprise webs 49 and outwardly extending langes '50.. The outer and inner channels 45 and Il@ are staggered, i. e., the channels of each series are positioned opposite the spaces between the channels 'of the other series. The inner and outer channels l5 and @i6 are in close radial juxtaposition, the edges of the res .ective anges 'i8 and 5! preferably lbeing in substantial alinement. Each channel being substantially wider than the spacing between the channels, its twoflanges are spaced beyond or overlap somewhat the near anges of the two next adjacent channels of the other series. Thus the two contiguous flan-ges of each associated pair of inner and outer channels define a tortuous air circulation passageway, which is of such a character as to exclude light from leaking therethrough. These tortuous air circulation passageways extend circumferentially around the cylindric part of the lamp casing, and are of sufficient total cross sectional area as to assure free and full circulation of air into and out of the lamp, with the result that the lamp will remain at low operating temperature even after prolonged use.

The lower ends of the outer and inner channels 45 and 46 are here shown to abut a deflector flange 55 that extends inwardly and upwardly from the upper edges of the side wall members 32 of bottom structure I3, and that has an outwardly and upwardly bent portion 56 positioned inside the lower end portions of the channels.

As here illustratively shown, the series of outer channels 45 terminate at each end frame of the lamp in a half-channel 45a, the web of which is received inside end frame flange 25.

Alternate channels 45 and 46 are connected each to the next by bracket members 58, such as shown in Figs. 3 and 4. These bracket members 58 as here shown comprise portions 6I secured as by welding to the central portions of the webs 48 of inner channels 46, and angle portions 62 extending from each end of portion 6| and engaging and secured as by welding to the flange and a portion of the web of an adjacent outer channel 45, all as will be clearly understood from inspection of Fig. 4. As here shown (see Fig. 1) there are four circumferentially spaced rows of such interconnecting bracket members 60, and

these taken together integrate the inner and outer series of channels into a unitary side wall structure. To further brace the side wall structure, I preferably employ a plurality of longitudinally extending sheet metal strips 10, laid flat on the outer surfaces of the outer channels and received underneath and secured to the marginal flanges 26 of the two end frame members Il and I2. The channels 45 are secured to longitudinally extending strips 'l0 in any suitable Way, as by welding. As here shown, there is one of the strips 'I8 at the top of the lamp, and to this top strip lll is secured a carryingV handle H for the lamp. Two of the strips 18 are at opposite sides of the lamp, in line with its central axis, and to these are preferably secured the trunnion mountings l2 for the usual yoke arms, fragmentarily indicated at 13. Two further strips l0 are lpreferably positioned at the lower ends of the channels 45, as appears in Figs. 1 and 5.

A pair of parallel longitudinal lamp carriage guide rods 88 are here shown as mounted on brackets 8l secured to end frames ll and l2, as shown in Fig. 2. Slidable on these rods 88 is a lamp carriage 82, of any suitable or conventional type, adapted to carry the usual incandescent light globe 83. Carriage 82 also supports a spherical reflector 84 to the rear of light globe 83, said reflector being designed to receive light from the filament 85 of globe 83 and to reiiect it back to a focus in the plane of the filament 85.` The lamp carriage 82, globe 83 and reflector 84 may be conventional and will require no detailed consideration herein. Fig. 1 shows a focusing mechanism suitable for sliding carriage 82 along guide rods 80, and comprising a bracket arm 86 extending from carriage 82, a link 8l pivotally connected to arm 88, a crank arm 88 pivotally connected to link 81 and mounted for rotation on side wall 32, and an exterior operating handle 89. Such a focusing mechanism is described and claimed in my prior patent, Re. 21,089, issued May 16, 1939. It will be understood that rotation of handle 88 will operate the crank arm 88 and link 81 to slide lamp carriage 82 longitudinally on rods 80, thus adjusting the position of globe 83 with reference to the lens 23 of the lamp, so as to adjust the focus.

The lamp of the present invention is now described as not only of simple construction and of attractive appearance, but assures a maximum of air circulation through the lamp without possibility of light escaping through the side walls of the lamp casing. The construction as described is especially effective in excluding downpouring water from the interior of the lamp. Water falling on the lamp, either vertically, or at a substantial slant angle, is received by the outwardly facing circumferential channels 45, travels downwardly around said channels to deilector flange 55, and is discharged from the lamp over the latter. If any water gets into the inwardly facing channels 45, it likewise travels downwardly to the deflector flange 55, a slight spacing being preferably provided between the lower ends of the channels 45 and flange 55 to permit escape of the water from said channels down the flange 55, as is clearly shown in Fig. 5. The lamp thus combines the features of simplicity of construction, maximum air circulation, effective light trapping, and complete exclusion of water.

One preferred and illustrative embodiment of the invention has now been shown and described; it will be understood, however, that this is for illustrative purposes only, and that various changes in design, structure and arrangement may be made without departing from the spirit and scope of the invention, or of the appended claims.

I claim:

1. In a lamp having a pair of spaced front and rear -generally circular end frames: a ventilated, water excluding and light trapping cylindric wall construction extending between and mounted at opposite ends on said end frames, said cylindric Wall construction comprising inner and outer rows of spaced circumferential channels extending longitudinally between the end frames and closely radially juxtaposed to one another, each such channel comprising a web and a pair of flanges extending in the same direction from opposite edges of said web, the channels of the outer row facing inwardly and the channels of the inner row facing outwardly, and the channels of each row being positioned opposite the spaces between the channels of the other row, and the spacing between channels being such that the two flanges of the individual channels of each of the rows extend beyond and receive between them the adjacent anges of the two adjacent channels of the other row, and means interconnecting all said channels to form an integrated structure.

2. In a lamp having a pair of spaced front 'and rear generally circular end frames: a ventilated, water excluding and light trapping cylindric wall construction extending between and mounted at opposite ends on said end frames, said cylindric wall construction comprising inner and outer rows of spaced circumferential channels extending longitudinally between the end frames and closely radially juxtaposed to one another, each such channel comprising a web and a pair of flanges extending in the same direction from opposite edges of said web, the channels of the 4outer row facing inwardly and the channels of the inner row facing outwardly, and the channels of each row being positioned opposite the spaces between the channels of the other row, and the spacing between channels being such that the two flanges of the individual channels of each of the rows extend beyond and receive between them the adjacent anges of the two adjacent channels of the other row, and relatively narrow supporting brackets connecting the individual channels of each row to each of the adjacent channels of the other row at a plurality of points spaced circumferentially around the channels.

3. In a lamp, the combination of a pair of spaced front and rear generally circular end frames, a cylindric wall structure extending between and mounted at opposite ends on said end frames and comprising inner and outer rows of spaced circumferential channels extending circularly around the sides and top of the lamp, said rows of channels extending longitudinally between the end frames and being closely radially juxtaposed to one another, each such channel comprising a web and a pair of flanges extending in the same direction from opposite edges of said web, the channels of the outer row facing inwardly and the channels of the inner row facing outwardly, and the channels of each row being positioned opposite the spaces between the channels of the other row, and the spacing between channels being such that the two flanges of the individual channels of each `of the rows extend beyond and receive between them 'the adjacent flanges of the two adjacent channels of the other row, a box mounted on and extending between the bottom sides of the two end frames closing the lamp at the bottom, and deflector members extending along the side edges of the box and positioned opposite the lower ends of said channels to divert any water travelling downwardly in said channels outside the side edges of said box.

4. In a lamp, the combination of a pair of spaced front and rear generally circular end frames, a cylindric wall structure extending between and mounted at opposite ends on said end frames and comprising an interlocking channel formation extending circumferentially around the sides and top of the lamp, said interlocking channel formation providing channels formed and arranged to trap water falling on the lamp and to convey any such water to the lower ends of said channels, a box mounted on and extending between the bottom sides of the two end frames closing the lamp at the bottom, and deflector members extending along the side edges of the box and positioned opposite the lower ends of said channels to divert any water travelling downwardly in said channels outside the side edges of said box.

JESS C. ROSE.

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