US2083506A - Focusing means for incandescent studio spotlights - Google Patents

Description

June 8, 1937. J. c. ROSE 2,083,506

FOCU SING MEANS FOR INCANDESGENT STUDIO SPOTLIGHTS Filed May 21, 1935 3 Sheets-Sheet 1 Dluerzfar .52; 6. Base.

June 8, 1937. J. c. ROSE 2,083,506

FOCUSING' MEANS FOR INCANDESCENT STUDIO SPOTLIGHTS Filed May 21, 1955 5 Sheets-Sheet 2 l I I I I I I I I I I I I I I I I I I I I I I I I l I l l I I I I I I I l I J l I I I I l Invenlur cfess'afiase.

a /6 I a l2 /4 m J. c. ROSE ,08

V FOCUSING MEANS FOR. INCANDESCENT STUDIO SPOTLIGHTS June 8, 1937 Filed May 21, 1935 5 Sheets-Sheet 3 Inventor- Jss 6. Rose.

Z54 I /Z llZ flllorrzey Patented June 8, 1937 ssssum FOCUSING MEANS FOR INC'ANDESCENT STUDIO SPOTLIGHTS Jess 0. Rose, Los Angeles, Calif., assignor to Motion Picture Electric Products, Los Angeles,

Calif., a corporation Application May 21,

15 Claims.

This invention relates generally to incandescent spot lamps such as are used in motion picture studios for illumination of sets, and more particularly to focusing means for the incandescent light globe of such lamps.

Studio spot lamps of the character mentioned are ordinarily provided with a light globe that is movable forwardly and rearwardly along the axis of the reflector for the purpose of adjusting the lamp to cast a relatively small spot of light, or else to spread the light out and flood the object. The spot is of course formed when the globe is at or near the focal'point of the reflector, and flood characteristics are obtained when the globe is moved nearer the reflector. It has been the practice to provide an operating means for adjusting the position of the globe between spot and flood positions involving a lead screw having screwthreaded connection with globe carrier member. Such lead screw is ordinarily rotated by a crank or similar. means, and a large number of crank rotations are required to move the globe between spot and flood positions. Obviously, adjustment of such a lamp involves considerable ef- 5 fort and consumption of time. The time factor involved in adjusting such lamps is of particular importance in the lighting of a motion picture set, since time is at av high premium, and when the taking of a scene is Waiting, a motion picture director is highly impatient with the slightest delay in making final lamp adjustments.

It is accordingly one object of the present invention to provide a quickly operating and generally improved means for adjusting the globe of an incandescent studio spotlight between spot and flood positions.

In accordance with a preferred form of the present invention, the light globe carriage is arranged to slide on a pair of guide rods which are parallel to the axis of the reflector, and the carriage is moved through a link connected at one end to the carriage and at the other end to an arm mounted on a manually rotatable shaft journalled in a wall of the lamp. The arrangement is made such that the full range of movement of the lamp globe carriage (between spot and flood positions) is accomplished by one revolution or less of the manual operating shaft, that is, within one revolution of said shaft, full adjustment being had in'present preferred forms of the invention by a 180 degree turn of said shaft. A suitable knob or handle is mounted on the manually operable end of the shaft, and the shaft carries a suitable pointer, with which is associated a scale 55 showing spot, flood, and intermediate positions.

of California 1935, Serial No. 22,546

Since in such an arrangement as thus. generally described, the light globe carriage moves rather freely on its guide rods, the manual adjustment means as described offering no particular resistance, the light globe carriage has a tendency to slide along the guide rods as the spot lamp is tilted up or down on its horizontal trunnion mounting axis. It is a feature of the present invention that such accidental movement or displacement of the light globe carriage in the course of ordinary operation is prevented. This is accomplished, in a preferred embodiment, by the provision of friction means which yieldingly resists adjustment movement of the light globe carriage on the guide rods. This friction means offers the necessary resistance to prevent accidental displacement of the carriage, 'but does not bind the operating means sufficiently to interfere with desirable ease of operation.

It is customary to transport lamps 'of the character mentioned piled one on top of another,.with the front faces of the lamps turned downwardly. The front lenses of the lamps are for thispurpose removed, and the crowned back of each lamp projects somewhat within the front opening of the lamp next above it. The lamp being "in such a position, the light globe carriage tends to work downwardly on'its guide rods as'the lamps are transported, even despite the frictional means provided to prevent movement in ordinary operation. As thelight globe carriage thus works downwardly, either the spill-ring carried by the carriage immediately in front of the globe, or

the globe itself, is apt finally to engage the v crowned back of the lamp next below. I If a spill- 1 ring is on the carriage, it is thereupon caused to be bent back, with the frequent result of coming against and breaking the globe, while if no spill-ring is in place, the globe may become broken by direct engagement with the crowned back of the lamp below. It is accordingly a further object of the invention to provide a lamp that has a comparatively freely moving light globe carriage, with a locking arrangement preventing the light globe carriage from accidentally moving forwardly from a fixed retracted position when the lamp is in a facedown position.

The invention will now be best understood ,by referring to the following detailed description of typical and preferred embodiments thereof, reference for this purpose being had to the accompanying drawings, in which: i

Fig. 1 is a front elevation of a'lamp embodying my invention, the front lens being removed and parts being shown in section;

Fig. 2 is; aev ertical section taken on line 2'-2 01 Fig; Lwi W ertain parts shown in elevation; Fig.2iris' a detail section taken on line 2a-2a, of Fig. 2;

Fig. 3 is a view similar to'a portion of Fig. 1,

but showing thelamp carriage in a different position;'

Fig. 3a is a, section as indicated by line 3a--3a 01 Fig. 3;

Fig. 3b is a detailsection taken as indicated by line Ob-Sb of Fig. 3a.; 1'

Fig. 4 is a detail sectiontaken as indicated by line 44 of Flg. 3;

Fig. 5 is a detail taken as indicated byarrows 5- -5 in Fig- 1;

Fig. 6 is a view similar to Fig. 4' but showing a modification;

Fig. 7 isa view similar to a portion of Fig. 3

but showing. a modification of the lamp carriage operating means; and

Fig. 8 is a viewof the back of the lamp, with the crowned back closure member broken away. I

The lamp,designated generally by numeral i0; is made-up of front and rear ring frame members' H and'l2, respectively, formed with inwardly extending flanges l3 and H (see Figs. 1 and 2).

Mountedwithin flanges l3 and are two substantially semi-cylindric shell or side wall 'meme bers l6. The lower edges of these side wall members define an opening which communicates with the interior'of a rectangular cas'e orboxylflil iigs. l and 3a). Ring flange members l3 and I4 terminate. at edges H, as indicated, inuFig. 311.

Box ll,.isiprovided' with brackets l8a:which engage the 'undersides .of the lower ends of flanges II and. I14, and screws 'l9 -passing-downwardly through side walls i6 andqflanges I3 and i4 threaded intobrackets 18w hold the parts in assembly, all as illustrated :in Figs. 3a: and 3b. Thiscasing member I8.is, designed to house certain operating mechanisms for the carriage;

etc.;;%and mayi'or the purpose of certain-of the claims be considered as;a part of the lamp frame. -Rearward gring Irame I2 has an opening 22 adapted to receive a-rear, annular-closure member 23 carrying va usual curved reflector mirror ,24. Thebackof'the reflector is yieldingly supported by an arrangementof four coil springs 24:; covered. with a suitable padding material, as jasbestos,'as indicated at 24b,.the junctures of the severalsprings being connected bymeansof supporting wires,Mo to,annularflmember 23. 7 The lamp has a crownedback member 23a, which is securedto member 2 3, asshown l ont; frame ring [I has an} annular. opening 25, which :receiyes a carriage ,ringj26 in which is mounted. firont..glass' orf lens" member .21. v The .is trunnioned one horizontalfaxis at 28 and 29 on the upper ends of supporting arms 32 mounted on a usual standard 33.

Theincandescentlamp globe is designated at 3i l,. and is shown mounted on a, lamp globe carriagef 3 l which'is adapted to slide forwardly and rearwardly,,.in a direction parallel to the axis of mirror 24,;ona pair of parallel guide rods 34 and 35 which are mounted at their ends 1111 brackets 36 formed on the inner surfaces of the ends of box ll. As clearlyshown,theserods are parallel to the axis of mirror "Hand are-fin a horizontal plane. Carriage 3i fis'providecl with'a bea'ring 31'which slides freely on guide rod 35, and with forward and rearward bearings and 39 which slide freely on' guide rod 34.

, Carriage 3| is shown provided with a forwardly extending bracket 40 on whjchis mounted the supporting arm 4| of a conventional spill-ring? 42, which is positioned immediately in front of "light globe, 30. As a means for detachablymounting arm M on bracket 4!), arm 4| is provided with an open-ended slot which is adapted to receive a clamp screw fr'nounted :in bracket 40, a wing nut 45 being provided on screw 44 .to

bear against the side of armll and thus clamp it tightly to bracket 40. It will be evident that this, construction permits the spill-ring to be easily and quickly mounted and dismounted.

The preferred'means in accordance with the H present invention for sliding lamp carriage 3i back'andforth on rods .34 and 35,'for the purpose of adjusting the lamp globe between flood and spot positions, will now be described. A horizontal operatingshaftifl is rotatably mounted inside wall 5| of box l8 (Figs. 2 and 4). This shaftis so located as to betothe rear of forward lamp-carriage bearing 38 when the lamp-car riage is in its rearward or flood position, as itis in. Fig. 2, and is located just below guide rods 34v and 35, as shown. Pinned on the inner end of shaft 50 is an arm-"52, the swinging end of. which is pivotallyconnected to oneiend of a link 53, the' other. end of link 53 being pivotally'connected at 54 with lamp-carriage bearing. "The outer end of shaftg50 is provided with an operatingknob 5'! provided with a handle 58 and a pointer 59, the latter -moving over scale Gilformedon a scale plate 6| :which is afllxed, as

by screws :62, to thepoutersurtace of wall 5|;

It willbe evident from a consideration of Figs;

2 and 3 that the-full range'of forward-and rear ward movement of the lamp carriage is accom plished by a 180 degree rotation oi shaft 50*and arm 52.' The lamp carriage is in} its" rearmost (flood-light) position when arm 52 is in ahori zontal rearwardlyextended position, and is in itsextreme 'forward position' -(spot) whena'rm L52 globe 30being substantially iat'thefocafpoint oi mirror 24 11 the latter position. The range of movement ofthe lamp carriage is of course deetermined by the length of amfsz, aiiid iink safis' 'is in a horizontal forwardly extending position,

of suchlength as will place the carriage and lamp in correctffulbfiood and spot, positions'in the two described positions of arm 52. Pointer 59 is so mounted on shaft 'as'to point straightthe carriage is illustrated. in aposition. close to ,spot, and in Fig. 5 the pointer is shownin a. corresponding position,

In the .positionof Fig. ;2, arm 52 is just above horizontal position and is in engagementwith guide rod .34, which overliesl arm '52 and pro: vides a stop-therefor (see Fig; 2a).. When arm-52 isithus in engagement with guide rod 34, pointer v 52'fis above"flood position, and its position is designated on scale .60. by the wordxlock. It will be' evident that inthis position of the device, the lampc arri'a'ge is-mov'ed slightly forward from its 'xtreme'rearward position, but that fur-. 'ther'forward movement is prevented by the en'- gagement of arm" 52 w'ith'the underside of guide rod 34. The advantage of this lock position will be explained hereinafter.

A friction means is provided to establish a desirable resistance to movement of the lamp carriage on the guide rods, so that the carriage will move easily when handle 58 is turned, but will not slide back and forth as the lamp is tilted up or down. As shown in Fig. 4, operating shaft-50 is provided just inside of wall with a friction disk 10, said disk in the present instance being provided with a hub 1| fastened to shaft 50 by means of pin 122. Disk comes against one side of a stationary friction disk 14 carried by the outer ends of the aforementioned screws 62, disk 14 being positioned between sleeves 15 bearing against wall 5|, and nuts 16 being screwthreaded on .the rear ends of the screws. Mounted on shaft so as to bear against the surface of disk 14 which is opposite disk10, is a friction disk 18, said disk 18 being provided with a hub 19 which is arranged to slide longitudinally on shaft 50 but is held against rotation thereon. For instance, hub 19 may be formed with a slot formed in a direction parallel to shaft 50, which slot receives a pin 8| set into said shaft. Friction disk 18 is thus splined on shaft 50. Encircling shaft 50 and bearing against the end of hub-19 is a compression spring 83, the other end of which seats against a collar 84 tightly mounted on shaft 50, all as clearly shownin Fig. 4. It will be evident that spring 83 presses friction disk 18 into tight engagement with one surface of stationary friction disk 14, and also acts through collar 84 and shaft 50 to press disk 10 into tight engagement with the other surface of disk 14, thus setting up a yieldable or frictional resistance to rotation of shaft 50. The adjustment of spring 83 is of course such, however, that shaft 50 may be turned without difficulty, only sufficient frictional resistance being set up to prevent carriage 3| from sliding back and forth on the guide rods -merely due to tilting of the lamp.

It will now be evident that I have provideda novel lamp carriage adjustment mechanism which is quick in action, simple in construction, and convenient in use. The operating handle, in thepreferred form of the lamp, is rotated through but one half of a turn to translate the lamp carriage over its entire range of movement. 'The mechanism moves easily, but is prevented from accidental displacement from a given position as the lamp is tilted, by the yielding friction means acting on the manual operating shaft.

When lamps of the type disclosed are to be transported, they are commonly stacked one on top of another, with their crowned backs up, and the front lens carrying rings removed, so that the crowned back of each lamp may be received within the open side of the lamp above it. When the lamps are so stacked, the operating handle is turned to lock position, which places the lamp carriage in the position of Fig. 2. In such position, as mentioned previously, arm 52 is past center and in engagement with guide rod 34, and the lamp carriage is stopped against sliding downwardly on rods 34 and 35, with the liability of finally breaking the light'globe.

Attention is called to the fact that the lamp carriage, guide rods, and focusing mechanism are supported exclusively on lower housing I8, and that this entire assembly may be removed simply by removing screws I9 that secure housing I8 to frame ring flanges I3 and I4.

Fig. 6 shows a modification of the lamp carriage operating means. The operating'link which is connected to the lamp carriage is again indicated at 53, and the casing wall and scale plate are again indicated by numerals 5| and 6|, respeotively. It will be understood that the lamp carriage and link 53 may be exactly the same as in the form previously described, as may the mechanism casing of which wall 5| is a part. A manual operating shaft is journalled in wall 5| on an axis which is located the same as is the axis of shaft 50 in the form of Fig. 4. The exterior end of shaft 90 carries a handle 9| and a pointer 92, and its inner end is reduced, as at 93, and is slidably received within a socket 94 formed in the end of a shaft member 95. Reduced shaft end 93 has a notch 96 adapted to receive and drivingly engage a cross-pin 91 set in socket 94. Shaft member 95, which is journalled in a bearing 98 carried by a stationary frame plate 99, is confined against longitudinal movement by means of a flange I00 near its inner end which engages the adjacent surface of bearing 38, and a collar |0| screwthreaded onto the shaft and positioned adjacent the opposite face of said bearing.

On the extreme inner end of shaft is pinned an arm 52', exactly similar to the arm 52 of :the previously described form shown in Fig. 4, the outer end of 'arm 52' being pivotally connected to the end of link 53, as in the previous instance. It will be evident that rotation of knob 9| and shaft 90 will cause shaft 95 to be rotated to swing arm 52 for the purpose of moving link 53 and so shifting the lamp carriage, substantially as in the previous form.

A locking device is provided to prevent accidental shifting of the focusing mechanism as the lamp is tilted. Pinned on shaft 90 adjacent the inner surface of wall 5| is a spur gear I06,

and normally meshing therewith is a stop element I01, which is set into wall 5|, as clearly shown in Fig. 6. It will be evident that with the parts in the position of Fig. 6, the stop element in engagement with the teeth of gear I 06 prevents shaft 90 from being rotated. But by grasping knob 9| and forcing shaft 90 inwardly until gear I03 is free of element I01, the mechanism may be freely operated. Shaft 90 is normally yieldingly held in the locked position of Fig. 6

by means of a coil compression spring I08 which is confined between flange I00 and the opposed face ofspur gear I06. Thus, tochange the focus of the lamp, knob 9| is grasped and forced inwardly against spring I08 to free gear I06 from element I01, and may then be rotated to accomplish the desired shift of the lamp carriage. When knob 9| is then released, spring I08 acts to move shaft 90 back to the position of Fig. 6, gear I06 moving back into locking engagement with locking element I01. The lamp carriage is therefore automatically locked against movement longitudinally on the guide rods at all times that knob 9| is not being manually pressed inwardly to operating position, and the lamp carriage is therefore prevented during normal use of the lamp from sliding back .and forth on its guide rods as the lamp is tilted.

Fig. '1 shows another variational form of the lamp carriage operating means. In this instance the lamp carriage is shown provided on its underside with a'rack ;I I2, and adapted to mesh with this rack. is a gear segment 3 fast on an operating shaft 4 which will be understood as journalled for rotation in the side wall of the enclosing case. Rotation of shaft II4, which i tordisposed within the-rearward portionlthere will'be understood as, accomplished-by a manual knob of the sametype as-illustrated in Fig. ,4, causes rotation of gear H3 to translate rack I I2 and the lamp carriage between its-proper. limits of operation. The diameter-of gear! llis preferably such as willcause translation of the lamp carriage betweensuchflimits by a half-rotation ofshaftill.

Shaft H4 is preferably provided with a friction retarding-means the same as is illustrated in Fig. 4, it being understood that Fig. 4 is illustrative of the friction means and operating knob used with shaft H4 of Fig. 7.;Itwillbenoted, however, that shaft ill must be rotated in a direction opposite to that ofshaft 50 of Fig. 4 in order to accomplish a'given adjustment of the lamp carriage. a

, Fig. 7 also shows locking means adapted to hold the-lamp carriage securely in aretracted position during transportation of'the lamp. For this purpose, gear member I I3 is provided with a rounded, portion I20 adapted tocome into engagement with anarcuate surface I at the outer end .of rack member H2 after gear ,il3 has been moved out of mesh with the rack at the inner; limit of lamp carriage movement.

It will be obvious thatwhen surface-I20 is in engagement withsurface -l 2l, the lamp carriage issecurely locked against translation on the.

.lustrative of and not restrictive on the broader claims appended hereto, for variouschanges in design, structure and arrangement may be made without, departing from the spirit and scope of said claims. a, w ;Iclaim:' .I g

1. In an incandescent studio spot lamp embodyinga lampcasing having a curved-reflecof, the combination of .alight globe ,carriage within said casing adaptedto carry, alight globe on the axis of said reflector, .means supporting and guiding said carriage for forward and rearward movement ;in a direction parallel; to: the

opticalaxis of saidreflector, whereby saidlight globe is movable between spot and flood'positions, a manually; rotatable shaft-extending through a wall of said casing on an, axis at right angles to the direction of carriage movement, an

' operative interconnection between-the portion of said shaft that is inside the casing and said carriage so arranged that the light; globe is moved between spot and full floodpositions with in one revolution of the manually rotatableshaft, and manual shaft rotating means operating on the exterior-portion of the shaft.

2. An incandescent studio spotlamp embodying a substantially cylindric lamp casing, a. curved reflector disposed within'the rearward portion thereof, a-depending mechanism enclosing cas-t ing joined -to,said-cylindric lamp-casingat the bottom thereof, said two casings opening into light globe is movablebetween spot and flood positions, a horizontal manually rotatable shaft ex: tending through a side wall of said depending mechanism enclosing casing and" disposed at right angles ,to .the:direction of carriagemovement, an operative interconnection between the portion of said shaft that is-inside the casing and -said1ca'rriageso arranged that the light globe is moved between spot and full flood positions within one revolution of. the manually rotatable shaft, and manual shaft rotating means operating onthe exterior portion'of the shaft. r

3, In an incandescent studio spot lampembodying a lamp casing having a curved reflector disposed within the rearward portion thereof, the combination of a light globe carriage within said casing adapted to carry a light globe on the axis of said reflector, means supporting and guiding said carriage for forward and rearward movement-in a direction parallel to the optical axis of said reflector, whereby said light globe is movable between spot and flood positions, a manually rotatable shaft extending through a wall of said casing onan axis at right angles to, the direction of carriage movement, an operative. interconnection between the inner portion of said shaft and thecarriage so arranged that the light globe is moved between spot and full flood positions within one revolution of the, manually rotatable shaft, and friction means yield-,- ingly resisting operation of the manual shaft. Y 4.. An incandescent studio spot lamp ,embodying a substantially cylindri'c side wall casing,.a curved reflector disposed within the rearward portion thereof, a depending mechanism enclosing casing joined to said side wall casing at the bottom thereof, said two casings opening into one another, aslightglobe carriage within said cylindric casing adapted to carry a light globe on the axis ofsaid reflectonfmeans: supporting and guiding said carriagefor forward and rearward movement in a direction parallel to the optical axis ofsaid reflectonwhereby said light globe is movable betwe'en'spot and flood positions, a'horizontal manually'rotatable shaft extending through a side wall of said depending mechanism enclosing casing and disposed at right angles to the direction of carriage movement, an

of said reflector, whereby said light globe is movablebetween spot and'flood positions, a manually rotatable shaft extending through awall of said casing on anaxisat right angles to the direction' of carriage" movement, an operative interconnection between the inner portion of the shaft and the light globe carriage, such that rotation of the shaft-through a given angle moves the carriage between spot and flood positions, a fric-' tion disk non-rotatably mounted on said manual shaft, and a stationary friction member frictionally engaged by said frictiondisk.

6. In an incandescent studio spot lamp embodying a lamp casinghaving a curved reflector disposed within'the rearward portion thereof, the combination of a light globe carriage-within'said casing adaptedv to carry a lightglobe on the axis of said reflector, means supporting and guiding said carriage for forward and rearward movement in a direction parallel to the optical axis of said reflector, whereby said light globe is movable between spot and flood positions, a manually rotatable shaft extending through a wall of said casing on an axis at right angles to thedirection of carriage movement, an operative interconnection -between the inner .portion of the shaft and the light globe carriage, such that rotation of the shaft through a given angle moves the carriage between spot and flood positions, a friction disk splined on said manual shaft, a coil spring member surrounding said shaft and arranged to press said friction disk in one direction on the shaft, and a stationary friction member frictionally engaged by said spring urged friction disk.

'7. In an incandescent studio spot lamp embodyinga lamp casing having a curved reflector disposed within the rearward portion thereof, the combination of a light globe carriage within said casing adapted to carry a light globe on the axis of said reflector, means supporting and guiding said carriage for forward and rearward movement in a direction parallel to the optical axis of said reflector, whereby said light globe is movable between spot' and flood positions, a manually rotatable shaft extending through a wall of said casing on an axis at right angles to the direction of carriage movement, an arm on the inner portion of said manual shaft, and a link connected between the swinging end of said arm and said carriage.

8. In an incandescent studio spot lamp embodying a lamp casing having a curved reflector disposed within. the rearward portion thereof, the combination of a light globe carriage within said casing adapted to carry a light globe on the axis of said reflector, means supporting and guiding said carriage for forward and rearwardmovement in a direction parallel to the optical axis of said reflector, whereby said light globe is movable between spot and flood positions, a manually rotatable shaft extending through a wall of said casing on an axis at right angles to the direction of carriage movement, an arm on the inner portion of said manual shaft, a link connected between the swinging end of said arm and said carriage, a friction disk splined on said manual shaft, a coil spring member surrounding said shaft and arranged to press said friction in one direction on the shaft, and a stationary friction member frictionally engaged by said spring urged friction disk.

9. In an incandescent studio spot lamp embodying a lamp casing having a curved reflector disposed within the rearward portion thereof, the combination of a light globe carriage within said casing, a pair of parallel horizontal guide rods extending parallel-to the axis of the reflector in the lower part of the lamp casing, said guide rods supporting said light globe carriage for sliding movement therealong, such that a light globe carried by the carriage moves along the axis of the reflector, a horizontal manually rotatable shaft extending through a wall of the casing just below and at right angles to said parallel guide rods, an operative connection between the inner portion of said shaft and the carriage so arranged that the light globe is moved between spot and full flood positions within one revolution of the manually rotatable shaft, and manual shaft rotating means operating on the exterior portion of the shaft.

10. In an incandescent studio spot lamp embodying a lamp casing having a curved reflector disposed within the rearward portionthereof, the combination of a light globe carriage within said casing, a pair of parallel horizontal guide rods extending parallel to-theaxis of the reflector in the lower part of the lamp casing, said guide rods supporting said light globe carriage for sliding movement therealong, such that a light globe carried by the carriage moves along the axis of the reflector, a horizontal manually rotatable shaft extending through the casing just below and at right angles to said parallel guide rods, an arm on the inner portion of said manual shaft, a link pivotally connected at one end to the swinging end of said arm, and extending'from said pivotal connection in a forward direction in the lamp to a forward pivotal connection with the light globe carriage, and manual shaft. rotating means operating on the exterior portion of the shaft. 1

11. An incandescent studio spot lam'pzembody'iing a substantially cylindric side wallic'asing, a curved reflector disposed within the rearward portion thereof, a depending mechanism-enclosing casing joined to said side wall casing at the bottom thereof, said two casings opening into one another, a light globe carriage within said cylindric casing adapted to carry a light globe on the axisof said reflector, means supporting and guiding said carriage for forward and rearward movement in. a direction parallel tothev optical axis of said reflector, whereby said light globe is movable between spot and flood positions,

a horizontal manually rotatable sh'aft extending through a side wall of said dependingmechanism enclosing casing and disposed at right angles to the direction of carriage movement, said shaft extending exteriorly of said casing and having an operating handle on its outer end, and an operative interconnection between the inner end of said shaft and the carriage so arranged that the light globe is moved between spot and full flood positions within one revolution of the manually rotatable shaft.

12. In an incandescent studio spot lamp embodying a lamp casing having a curved reflector disposed within the rearward portion thereof, the combination of a light globe carriage within said casing. a pair of parallel horizontal guide rods extending parallel to the axis of the reflector in the lower part of the lamp casing, said guide rods supporting said light globe carriage for said sliding movement therealong, such that a light globe carried by the carriage moves along the axis of the reflector, a horizontal manually rotatableshaft extending through a wall of the casing just below and at right angles to said parallel guide rods, an operating arm on the inner portion of said manual shaft, and a link, pivotally connected at one end of the swinging end of said arm and extending from said pivotal connection in a forward direction in the lamp to a forward pivotal connection with the light globe carriage, said arm and link being so arranged as to move the carriage from its extreme rearward to its extreme forward position by a movement of the arm from a rearwardly extended position downwardly and around to a forwardly extended position, the swinging end of said operating arm being located directly below one of said guide rods, and'being engageable therewith when said arm is raised from said rearwardly extended position to a position above horizontal to afford a stop to for ward movement of the carriage.

= I .213; Inan incandescent studio spot 'lamp emibodying a lamp casing having a curved reflector :disposedwithin the rearward portion thereof the whereby said light globe'is movable between spot and flood positions; a horizontal manually rotatable shaft 'j'ournalled in said casing on an axis tatri'ghtzangles to the direction of carriage move- 'ment,. a irotatableu'shaft journalled in line with saidmanually rotatableshaft, an operative connectionlbetween the last mentioned shaft and the lamp carriage, a-sliding driving connection betw'engsaid shafts such that the manual shaft maybe moved axialiywithout breaking'its driving zconnection with the other shaft, a locking member on said manual shaft, a stationary looking element engageable with said locking memberitoilockthe manual shaft against rotation in Gone .axiaLposition of said shaft, and a' spring iyieldingly urging said manual shaft to such locking position, but yieldable to allow the manual shaft tobe moved axiallyto disengage'said looking member from said locking element.

14. In an incandescent studio spot lampembodyingJa lamp casing having a'curved reflector disposed within the rearward portion thereof, the conibinationof a light globe carriage within said casing adapted to carrya light globe'on the axis of. said reflector',tmeans supporting and guiding said carriage forforward and rearward'movement in "a direction parallel to theioptical axis of said reflector, whereby said light globe is movable between spot and flood positions, a rack on the lampcarriage extending parallel to the direction of carriage movement, a manually rotatable shaft extending through a wall of saidcasing on an axis at right angles to the direction of carriage movement, manual shaft rotating means j operating on the exterior portion of the shaft, and a spur gear on saidshaft meshing with said rack, saidspur gear being of such size that the light globe is moved between spot and full flood positions: within one revolution ofsaid rotatable shaft. a

15. An incandescent studio spot lamp embody ing a substantially cylindric lamp casing, a curved reflector disposed within the rearward portion thereof, a depending: mechanism enclosing .cas-f ing detachably mounted on thelower side of said lamp casing, said two casings opening into one another, a light globe carriage within said cylindric lamp casing adapted to a carrya light globe on the axis of said reflector,.means mounted on said detachable casing supporting and guiding.

said carriage for forward andrearward movement in a direction parallel to the optical axis of said reflector, whereby said light globe is movable between spot and flood positions, .a horizontal manually rotatable shaft extending through a side wall of said depending mechanism enclosing casing and disposed at right angles to the JESS c. ROSE.

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