Патент USA US2405286код для вставки
Aug. 6, 1946. I H. K. BOURNE v I 2,405,286 ELECTRIC VAPOR LAMP APPARATUS AND METHOD OF OPERATION Filed Aug. 25, 1944 mm /,/ /,’/ /Q ‘7. 4 f/WE/vm'z ' .5)’ HARRY KBUUR/Vf mm H5 ATTORNEY Patented Aug. 6, 1946 2,405,285 UNITED STATES ‘ PATENT‘ "OF-Fl cs 2,405,286 ELECTRIC VAPOR LAMP APPARATUS AND METHOD OF OPERATION Harry K. Bourne, Rugby, England, assignor to‘ General Electric Company, a corporation of New York Application August 25, 1944, Serial No. 551,184 In Great Britain January 2, 1943 1 ' 6 Claims. (01. 315-118) ~ This invention relates to electric discharge A lamps generally, and more particularly to equip ment for and methods of operating such lamps. It is frequently desired to reduce periodically the light output from high pressure mercury vapor lamps of the compact source type while axially from the rear of the re?ector, which may be of‘ parabolic shape,’ and the lamp is held in a carriage slidable within the heat conserving jacket, a cap being arranged on the carriage to co-operate with the aperture in the re?ector leading to the jacket. Thus when" the lamp is retracted into the jacket, the cap covers the aper enabling maximum light output to be imme diately available. In order that these conditions ture and completely prevents light emission, may apply, it is essential that, during the periods while at the same time completing-the enclosure of‘reduced light output, i. e. of reduced power 10 of the lamp in the jacket- When the lamp is input, the discharge in the lamp should'be main ejected from the jacket it moves into a position tained or “simmered.” To do this, it is necessary to provide means for avoiding loss of heat from in which the source of light is located at the focus of the re?ector, the cap moving with the the envelope or for supplementing the'heating lamp and serving to preventthe emissionof of the envelope to avoid too great a reduction of 15 direct rays from the lamp. . , r ' ' the vapor pressure within the envelope. ' An object of the present invention is to provide a simple means for enabling a lamp of the kind set forth to beoperated under simmering con ditions. ~ ' ‘ To enable the invention to‘ be ‘more readily understood reference is now directed to the ac companying drawing which shows somewhat diagrammatically and in section an arrangement according to the invention. The invention consists in providing a heat con serving jacket between which and the lamp rela tive movement is effected during the change-over from vmaximum light output to simmering con ditions, the. jacket enclosing the lamp and shield . , Referring to the drawing the discharge lamp l is mounted in a suitable holder 2 forming part of a carriage movable with relation to a heat conserving jacket 3 which projects axially from The jacket 3 is pro ing it both thermally and optically during the vided with suitable lagging 5. time that it is operated under simmering con The jacket 3 is closed at its right-hand end by ditions. . a ?xed plug 6 having a central aperture in which The heat conserving jacket thus serves, in ad slides tube 1 forming part of the carriage and dition, as an optical shutter, and is arranged 30 containing the leads 8 which convey operating to surround the lamp and substantially com-' potential to the lamp I from a source of poten pletely enclose it during simmering conditions. tial H, II through an inductance (choke coil) 12. ‘When moved relative to the lamp to permit max . In the drawing the carriage is shown in the imum light emission therefrom, this movement position in which the lamp is ejected from the takes place simultaneously with the operation 2.3 .or heat conserving jacket 3 into a position in which of switching means for eifecting the removal of the light source is located, preferably at the focus series resistance or inductance from the lamp of the re?ector 4 which may be of parabolic circuit, whereby to increase the operating cur shape. The position of the carriage is limited rent through the lamp and enable the increased by an adjustable stop 9 ?xed to the tube 1 which light output to be available. When the relative 4.0 abuts against the plug 5. The carriage is also movement of lamp and jacket is reversed, the provided with a cap 09 which in the retracted resistance or inductance is re-inserted in the lamp circuit. _ ' the rear of a re?ector 4. position covers the otherwise open end of the heat conserving jacket 3 and limits the extent In one convenient embodiment, the heat con of movement of the carriage in the retracted serving jacket is constituted as part of a re ‘ position. In the position indicated the cap I!) ?ector utilized for forming into a beam the light also serves to prevent the emission of direct rays emitted from the lamp. Then, during the periods from the lamp I. when the lamp is to be operated under simmering Switching means are provided whereby in the conditions and no light emission is desired, the ejected position illustrated the power input to lamp is retracted into the jacket; whilst when 50 the lamp is increased, while in the retracted po light emission is desired, the lamp is ejected sition the power input is diminished causing the from the jacket into a position within the re lamp to simmer. This may be effected by in ?ector at which the source of light is situated serting into the circuit With the lamp additional at the focal point of the reflector. In one ar series resistance or inductance I3. The added rangement the heat conserving jacket projects inductance or resistance may be inserted auto ' 2,405,286 3 matically by providing contacts carried by the 4 which the carriage is provided with a cap which, in the retracted position of the carriage, covers the otherwise open end of the jacket and com pletes the optical and thermal shielding of the tube 1 to effect the desired change of circuit con nections. In the drawing, I have shown a ?xed contact [4 and a movable contact l5 on the tube lamp. ‘I. In the ejected position, the contacts l4, [5 are 3. The invention as set forth in claim 1, in closed to shunt the added inductance 13;. Retrac which a re?ector is provided and in which the tion of the tube 1 opens the contacts to insert the carriage is provided with a cap which, in the re inductance l3 in series with inductance l2. The tracted position of the carriage, covers the other are between the electrodes is satisfactorily main tained under simmering conditions by the pro-‘ 10 wise open end of the jacket and completes the optical and thermal shielding of the lamp, and vision of the heat conserving jacket which pre-Y in which the jacket projects axially from the rear vents cooling of the lamp and maintains the of said re?ector which is adapted to direct the mercury vapor pressure within the :envelope light from the lampwhen ejected from the jacket, thereof. the cap preventing the emission of direct rays If desired; the retraction of the lamp into the. from the lamp in the ejected position and cov heat conserving jacket may be effected electro-g ering the aperture in the re?ector when the car magnetically by making the carriage form the riage is retracted into the jacket. armature of an electromagnet energized by suit 4. The combination of a high pressure mercury able switching means operated from a point re mote from the lamp. This switching means may 20 vapor electric discharge lamp of the compact then be arranged simultaneously to insert the ad ditional series inductance or resistance simul taneously‘ with the retraction of the lamp car riageinto the jacket. Preferably the lamp is constructed in the man ner disclosed in the British Patent No. 550,581 since the construction enables all the necessary supply conductors for the lamp to be connected thereto at the end of the lamp which is at all times within the jacket. The arrangement shown may be utilized as a means for providing an intermittent beam of light for signalling purposes. source type, supporting and positioning structure comprising a fitting embodying a, heat conserving jacket and a carriage retractable thereinto and serving to support and selectively position the lamp in either a substantially ejected light emit ting position or in a position substantially en closed by said jacket, and means actuated by said carriage for connecting ahigh power source to said lamp when in its ejected position and a lower power source to said lamp when in its retracted position. 5. The method of operating a high pressure metal vapor electric discharge device which com What I claim as new and. desire to secure by prises alternately applying relatively high and Letters Patent of the United States is: I. In combination, a high pressure mercury low power across the terminals thereof, and en closing the device. in a thermal insulating jacket only during the periods of operation at loW power. (-7. In combination, a high pressure mercury va porting and positioning ?tting comprising a heat por lamp of a compact source type, a supporting conservingv jacket, a circuit for supplying power to said lamp, a carriage for supporting the lamp - and positioning structure for said lamp compris ing a heat conserving jacket, a carriage for sup and movable with relation to- the jacket so that porting said lamp and movable with relation to when the carriage is retracted into the jacket the jacket to eject said lamp from the jacket‘ or the lampv is thermally and optically shielded, and retract it thereinto so that when retracted into means simultaneously operated by the movement the jacket the lamp is thermally and optically of the carriage for reducing the power input to shielded thereby, a source of high power, a source the lamp when the carriage» is retracted into the of low power, and means responsive to the posi jacket, to an extent such that the lamp is oper tion of said carriage for selectively connecting ated under simmering conditions when shielded the high power source to said; lamp in its ejected by the jacket and full light output from the lamp is immediately available when the power input 50 position and the low power source to said lamp in its retracted position. is increased upon the carriage being ejected from vapor lamp of the compact source type, a sup the jacket. 2'. The invention as set forth in claim 1, in HARRY K. BOURNE.