US 908117 A
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Description (OCR text may contain errors)
T. E. MURRAY.
LIGHT REGULATOR IOR ELECTRIC LAMPS. APPLICATION FILED PEB.11. 1907.
908, 1 1 7. Patented Dec. 29, 1908.
2 SHEETS-SHEET ,1.
W|TNE$$E$= 1. i I INVENTOR 614% Y #9 ATTORNEY T.- E. MURRAY.
LIGHT REGULATOR FOR ELECTRIC LAMPS.
APPLICATION FILED FEB.11. 1907.
908, 1 1 7, Patented Dec. 29, 1908.
2 SHEETS-SHEET 2.
INVENTOR ATTORNEY plates 14 and the under sides of perforated plates .17, 18, are
"THOMAS" MURRAY, or nnwfroaxpnr.
LI GET-RE GULA'I. OR FOR ELECTRIC JLAMPS- Specification of Letters Patent.
Patented Meet,- 1908.
Application filed February 11,.1907.. Serial No. 356,836.
To. allwhom it may. concern:
Be it known that I; THOMAS E. MURRAY, a. citizen ofntheUnited-States, residing at New York, in the county of New York and State'of N ew- York,.have invented a certain new.-and useful Improvement in Light-' Regulatorsfor Electric Lamps, of which the following is a specification.-
The invention. is an, apparatus for-increasing ordiminishing'the intensity of the light emitted by=an eleotriclamp by producing, in..the lamp circuit currentvariationsof predetermined. frequency and varying the relativecperiodicities of saidvariations.
The invention consists in the construction of the device and the means for supplying liquid (llBl6OtIlC. t0 the contacts,. as more particularly set forth. in the claim.
.In. the. accom anying. drawings, Figure 1.. is. a horizonta sectiom of. .the apparatus .011 the .line a: a:.-of Fig. 3. .Eig- 2. is a section on the=line y y of Fig. 1. Hi 3.is a vertical-section on .the line 2 z. of Fig. 4.is a plan vieW'of the le-verand associated erforatedplate.
Simi ar-numbers. of .referenceiindicate like parts. I
ylindrical: box filled with oil or other liquid dielectric (not shown).
2 is a central shafthavingits. lower por- 3 insulated from tion disposed in \a' etc the flange 4, above box 1, and provided wit which'said shaft passes through the insulated bearing 5 and is connected to the shaft of a motor 6, by the ordinary flanged coupling 7. The motor may be supported by a bracket 8 on the coverplate 9 of box The central shaft 2 Within the box is squared at-11, to receive the hubs 12 of the metal contact plates 13, each having a plurality of arms. Between the arms of each contact plate 13 are perforated plates 14 ofrubber or other hard insulating material which are sup orted by the metal strips 15 secured to t e under sides of said plates 13, in any suitable way. The 14 are cut away around the shaft 2 to form a central aperture at 16, and two openin s ormed in each plate on one si e of each arm of each contact plate 13. On
the under sides of the said plates14 and extending below in front of said openings and also extending radially across .the central a erture 16 are buckets 19, 20, 21, having t eir concavities turnedin the shaft carries a surface of..the..eontactdplates 13. .and
-13 to shaft 2 grammatical same. (direction, those of the buckets .19,
20, being below. openings 17,. .18.
: 22. is. a .-shaftdisposed in. aprojecting portion 23nOf box 1, received at. its lower ..end-.in a stepb24- (dotted lines Fig. 3) and passing throu h aninsulated bearihg 25 .in thecover p ate. 9. At its upper and said ever 26, which extends-over aperforated late 27hsupportedin cover 9 -and is provi ed. with a vertically movable headed. pin-28, wl1ich..may be insertedin any=opening .in-plate 27. Within the. box 1 the shaft v22rcarries aseries of collars v29, each faston the shaft and each provided with an arm- 30,.hav ing.atzi-ts enda contact spring 31 bent-to resent a flat-surface'on its. under. side. :liiasmuch as ..the 11 per 7 o the erforate plates 1 4 I are .inlthe fie contactsprings alwaysbear eithenon the armaofthe contactplates-13 or'lon the .intermediataplates .14.
The .icircuit z in the v.a paratus. proceeds from the-bearing. 25 to .slihft 22 toithe several. contact springs 31, to. contact plates and bearing. 5. The bearings 5. and 25=maybe connected with anydesired number of low lights .as indicated ..dia-
y at 32.
intermediate he operation of .the deviceidepends upon .ithefprinciple fir st,lthat thehumaneye 1811111- able to recognize interruptions in a ray from a luminous focus, if the frequency of said interruptions exceeds a certain rate er second; second, that the luminous intensity of the apparently unbroken ray can be varied by varying the duration of the intervals. T e resulting ph sical effect on the eye is that of an unbrolien ray which is decreased or increased in luminous intensity at will. Assume now that the shaft 2 is rotated by electric motor 6, so that the arms of the contact plates 13 move in the direction of the arrow in Fig. 1. Obviously circuit will be completed to the lamps whenever the arms of t e metal contact plates 13 come under the springs 31, and for a period represented by thedistance in are a, b, in Fi' 1. Circuit will be broken during the perio represented by the distance in arc b, 0, when the insulating plate 14 runs under the spring. The spec of rotation of shaft 2 is, however, to be such that the number of makes and breaks in the circuit to the lamps, or in other words, the number of interruptions of current in the lamp circuit-is to be greater per second than is moved outwardly and decreased as it is the luminous intensit the eye can appreciateI Now suppose the arm 30 to be swung outwardly by turning its shaft 22, so that the center line of said arm comes to the position b" Fig. 1. Then the eriod of time during which circuit is made to the lamps is somewhat reduced, and is represented by the distance in are a, I), while the period during which the circuit is broken, represented by the distance in are b c is greatly increased. On the other hand, if the arm be swung inwardly so that the center line of said arm comes to the position b then the period of time during which circuit is made to the lamps is somewhat increased and is represented by the distance in are a 5, while the period during which the circuit is broken represented by the distance in are l) c is greatly decreased. In other words, as the arm is swung on its shaft the relation of the periods of make and break is altered, the break periods being increased as the arm moved inwardly.
In practice the arm 30 is moved to its outermost osition and the speed of the shaft 2 is regu low thus indicating that although the rea in the circuit are at a maximum with respect to the makes, they are occurring with a frequency too great for the eye to recognize them. The degree ofv luminosity of the lamps will then bear a relation to the relative periodicities of the makes and breaks and be at a minimum. As the arm 30 is moved inward these relative periodicities change, and as those of the breaks constantly diminish 'of the lamps con stantly increases, so t at inorder to vary said intensity it is simply necessary to turn the arm 30 in one direction or the other by ated until the lamps show steadyv m dially disposed contact means of lever 26, and when the desired in tensity is obtained the lever may be secured by inserting pin 28 in the proper aperture of plate 27.
The object of filling the box 1 with oil is to prevent sparking or arcing as the contact arms run from under the springs 31, and this is still further avoided by means of the buckets which constantly take up the oil and project it in streams through the adjacent openings.
Une ractical application of the device to which y actual experiment I have found it applicable is the regulation of the intensity of numerous glow lamps simultaneously. Thus in theaters and public halls, the, lights can be raised or lowered as gradually as may be desired and to any chosen degree, and be held indefinitely at any selected intensity.
it will also be noted that the present device entirely obviates the necessity of the introduction in the lamp circuit of resistance coils or other energy consuming contrivances in order to vary the luminosity of the lamps.
I claim I The combination of a box for containing a liquid dielectric, a rotary shaft therein, a ralate on said shaft, a contact v supported in ependently of said shaft, bearing, on the surface of said plate and movable in a direction radial to said shaft and buckets on said. plate having inclined surfaces for projecting said dielectric upon the bearing surface of saidcontact. In testimony whereof l have afiixed my signature in presence of two witnesses.
THOMAS E. MURRAY.
PETER P. SMITH, ARTHUR H. Sronn.