US2057644A

US2057644A - Reflector projection lamp

Info

Publication number: US2057644A
Application number: US709658A
Authority: US
Inventors: Theodore O Hall
Original assignee: Hall & Connolly Inc
Current assignee: Hall & Connolly Inc
Priority date: 1934-02-03
Filing date: 1934-02-03
Publication date: 1936-10-13
Anticipated expiration: 1953-10-13

Description

Oct. 13, 1936. T. o. HALL REFLECTOR PROJECTION LAMP Filed Feb. 3 1954 3 Sheets-Sheet 1 INVENTOR fi m/209E Y HALL iw /j IS ATTORNEY Oct. 13, 1936. Q HALL 2,057,644

REFLECTOR PROJECTION LAMP Filed Feb. 3, 1954 3 Sheets-Sheet 2 mlohh l6 INV ENTOR 7Z/E000RE HALL JZLZMQMMM HIS A ORNEY Oct. 13, 1936. T. o. HALL 2,057,644

REFLECTOR PROJECTION LAMP Filed Feb. 3, 1934 3 Sheets-Sheet 3 VIII/1301A O Z.- T r:

il I) II II II) II II II Illlllllll INVENTOR ZZ/EoDORE HALL Patented Oct. 13, 1936 2,057,644 REFLECTOR PROJECTION LAMP Theodore 0. Hall, West Los Angeles, Calif., as-

signoito Hall & Connolly, Inc., New York, N. Y., a corporation of New York Application February 3, 1934, Serial No. 709,658

8 Claims.

This invention relates to projector lamps especially adapted for the projection of motion pictures. The high intensity flaming arc light has come into use for such lamps to a great extent on account of its high intrinsic brilliancy but complications, high cost and the heavy current used in most of such lamps have militated against its use in the smaller playhouses. One object of this invention is to devise a high intensity projection lamp of moderate current consumption and extremely simple and inexpensive design. By pointing the positive electrode away from the projector lens and employing a reflector, the quantity of light on the screen may be greatly increased. I have also simplified the construction of the standard high intensity, lamp by eliminating the rotation of the positive electrode which has enabled me to greatly reduce the size of the positive electrode holder thereby decreasing the shadow cast thereby.

A further improvement accomplished by my invention is the rotation of the reflector whereby uneven heating of the same is avoided and also the bad effects of flaws in the surface of the reflector substantially reduced.

Referring to the drawings showing a preferred form of my invention,

Fig.1 is a side elevation, partly in section, of my improved projector lamp unit with the hous- 30 ing omitted.

' Fig. 2 is a rear elevation of the same.

Fig. 3 is a horizontal section taken through the negative holder.

Fig. 4 is a detail of the feeding means for one 35 of the electrodes.

Fig. 5 is a section 5-5 of Fig. 4

Fig. 6 is a rear face view of the reflector rotating gear.

Fig. '7 is a vertical section taken on line 1-1 of Fig. 6.

Fig. 8 is a front view of the feed rollers for the positive electrode. r

The lamp structure is shown as comprising a taken approximately on line 45 back or baseplate l, to the outside of which is secured the lamp operating mechanism including the driving motor 2 and the blower 3 driven therefrom. Detachably secured to the inside of said plate is the supporting framework 4 of the lamp 50 proper. Said framework is shown as hollow and engages at its rear end the end of the insulated tube 5 projecting from the blower so that air is discharged therefrom through the hollow framework. On top of said framework are mounted l5 bracket 6 and bearing blocks 1 and I, said blocks having journalled therein a plurality of sleeves supporting the negative electrode 8. Next to said electrode is shown a split sleeve 9 which is caused to tightly grip the electrode at its forward end by inclined surfaces thereon which are engaged by the inner tapered surface of the second sleeve l0, said sleeve being threaded at its rear end in a sleeve ll pinned to the inner sleeve 9 so that the outer sleeve may be rotated and drawn rearwardly with respect to the inner sleeve to tightly clamp the electrode. The outer sleeve I0 is also shown as provided with rack teeth l2 at one side thereof with which mesh the teeth of a pinion l3 on a vertical shaft M for feeding the negative electrode. A striking knob 11 is also shown on the outer end of said sleeve. To strike the arc, knob IT is pushed inwardly to contact the electrodes. This winds up torsion spring 80 connecting the upper and lower parts of shaft l4 until lugs 8| and 82 on

collars

83 and 84 contact. Upon release of the knob, the spring unwinds and draws the arc.

I show the negative electrode holder as projecting through an aperture in the center of the reflector I 3. As shown, the reflector is tightly clamped at its center between a flanged nut l4 and a flanged sleeve I5 with suitable shock and heat absorbing washers l6, l6 therebetween. The

sleeve I5 is sho'wn as rotatably mounted in bracket 1 and as secured to the hub of a gear I l, which is rotated from a pinion l8 on shaft Hi. It will, therefore, be readily apparent that the reflector may be revolved at any desired speed by rotating the shaft l9.

Instead of rotating the positive electrode, I maintain the symmetry and depth of the positive crater by imparting a wabbling or rotary motion to the tip of the negative electrode. This distributes or revolves the negative flame around the crater of the positive electrode and prevents unequal side burning. This may be conveniently accomplished from the mechanism which rotates the reflector. To this end I have shown the gear II as provided with an eccentric interior bore 20 within which is rotatably mounted the reduced end 2| of an exterior non-rotating sleeve 22. Said sleeve is shown as housing the pinion l3 and is provided at its rear end with a spherical seat 23 engaging countersunk opening in the fixed upright 6. Therefore, as gear I! is revolved it will oscillate sleeve 22 about a point in the axis of electrode 8 as a center, thus oscillating the negativeelectrode as a whole about said center and causing the tip thereof to describe a small circle of about the diameter of the crater of the a positive electrode but without rotating either the

points

26 and 21 for cooling the negative holder and also at point 28 where baffles 29, 29' are placed to direct a current of air over the face of the reflector to cool the same and prevent deposits thereon. Air also passes through the passage 30 up through the hollow positive holder 25 to cool the positive holder and electrode, air also emerging at ii for the same purpose.

The feeding of the positive electrode is shown as effected from a feed shaft 32 by means of a worm l3 meshing with wormwheel 34 which drives a large gear 35 through idler 36. Gear 55 constitutes the lower feed roller and is shown as provided with a V-shaped groove 31 for this purpose. Above said electrode is shown an upper roller 58 which may be geared to the lower roller and is held clamped against the same by means of a spring 39 which exerts a pressure in a counterclockwise direction around the pivot point 40. Preferably current is introduced to the positive electrode through the feed rollers so that the usual heavy contact brushes are eliminated. In front of said rollers there is preferably placed an insulated shield 90 to prevent the are striking back to the rollers. A rearward supporting roller 42 may also be provided. For operating the feed shafts, I have shownshaft 32 as connected through universal and detachable couplings 44 to shaft 45 extending through the backplate I. Similarly the negative feed shaft ll, is shown as having a wormwheel 46 on the bottom thereof operated from a worm 41 on a shaft 48 which is connected through detachable coupling 49 to a shaft 50 journalled in said backplate.

Said feed shafts are preferably both operated from the same driving motor at proper speeds to maintain the crater of the positive electrode at the focus of the reflector and to maintain the proper arc length. To effect this purpose I have shown roller or-ball clutches 52, 53 (hereinafter referred to as roller grip type clutches) on the shafts, against both of which is shown a spring brake 18. Each clutch may comprise a camshaped plate 54 (Fig. 5) having a pin 55 extending outwardly therefrom through cover plate 54' and entering a slot 58 (or 56) in a reciprocated side rod 51 operated from a lever 58 pivoted at 55 and oscillated from a connecting rod 60 connecting said lever 58 and a crank pin ii on a gear 62 rotated from the motor 2 by means such as worm 83. When pin 55 is rotated counterclockwise in Fig. 4, for instance, rollers will grip the housing 53 to rotate the same. will rotate shaft 50 through slip friction clutch I! which is pressed against 53 by spring 81. The extent of step-by-step motion of each clutch may accurately be adjusted in infinite steps by means of threaded

shafts

85 and 66 which engage respectively stops B1 and 58 on each of cover plates 54' to limit the back strokes of the plates 54. By this means the rates of feed of each electrode may be adjusted so that each is fed at the proper rate to maintain the proper position of the positive crater and the proper arc length. For quick hand feeding, a knurled head 69 is provided for each feed shaft. One spring ll may be provided for returning both ratchet feeds after actuation, the spring being shown as connected across between the two

pins

55 and 55. The upper end of lever 58 is shown as carrying a pawl 13 for rotating the ratchet 14 on the shaft 15, which is coupled to the shaft l9 above described for rotating the reflector and oscillating the negative tip.

In accordance with the provisions of the pat ent statutes, I have herein described the principle and operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. is designed to use the various features and elemerits in the combination and relations described, some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use.

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

1. In a high intensity flaming arc lamp having a positive and negative electrode, of a stationary holder for the positive electrode and a revolvable holder for the negative electrode for bodily revolving the tip thereof so as to describe a small circle in front of the crater of the positive electrode and concentric with the major axis or core of the same, whereby a symmetrical crater is maintained.

2. In a reflector type projector lamp, a pair of electrode holders, a reflector, means for rotatably mounting the same, and means for continu ously rotating the same, whereby uniform cooling is secured and the ill effects of imperfections in the reflector surface overcome.

3. In a reflector type projector lamp, a pair of electrode holders, a reflector, means for. rotatably mounting the same, means for continuously rotating the same, and means actuated by rotation of said reflector for causing the tip of one of the electrodes to describe a closed figure in front of the other electrode.

4. In an arc projector lamp, an electric motor for feeding both electrodes, a feeding shaft for each electrode, and variable speed means connecting said motor and each of said feed shafts comprising a pair of roller griptype clutches, a slide rod reciprocated by said motor, and having a lost motion connection with each clutch, and independent means for varying the amount of rotation imparted to each feed shaft per stroke of said rod.

5. A variable speedfeed for an electrode of an arc lamp comprising a. source of power, a feed shaft, a roller grip type clutch connecting to said shaft to rotate the same step-by-step, a member reciprocated by said power source, having a lost motion connection to said power source, a spring for returning said clutch after each stroke, and an adjustable stop to vary the effective stroke of the clutch in inflnite steps. a

6. In a reflector arc lamp, an electrode holder comprising a fix support, a sleeve normally gripping the electrode, means for advancing said sleeve for feeding the electrode, a rotatable element around said sleeve journalled in said sup port and having an eccentric aperture therein, a reflector secured to and insulated from said element to be rotated thereby, and an intermedi- AlSO, While it ate sleeve journalled at one end in said element and having a universal mounting at a remote point in said fixed support, whereby rotation of said element wabbles the inner sleeve and the tip of the electrode.

7. In a reflector type projector lamp, a negative electrode holder, a reflector rotatably mounted thereon and having a. central aperture through which the electrode normally projects, means for 10 insulating the reflector from its mounting, and

means for circulating air over the reflector for cooling the same.

8. In a reflector type projector lamp, an electrode holder comprising a fixed support, a sleeve journaled therein, a reflector having a central aperture therein clampedin said sleeve, means for continuously revolving the sleeve and reflector, and means for feeding an electrode through said sleeve.

THEODORE O. HALL.