Патент USA US2134574код для вставки
Oct. 25, 1938. 2,134,574 E. B. PINKL:E ELECTRIC I'NCANDESCENT LAMP Filed Aug. 24, 1937 Figl. 4-1/0 lrwverwtor: Emma B Pinkie, ' He A’otor‘ney. 2,134,574 Patented Oct. 25, 1938v . UNITED STATES PATENT OFFICE - 2,134,574 ELECTRIC INCANDESCENT LAMP Emma B. Pinkie, East Cleveland, Ohio, assignor to General Electric Company, a corporation of New York Application August 24, 1937, Serial No. 160,621 ' 3' Claims. My invention relates to electric incandescent lamps and more particularly to'high wattage lamps. Still more particularly, my invention relates to an improved joint between the lamp ?lament and its leading-in conductors. 5 (Cl. 176-38) l5-l 5, of molybdenum for example, welded there to and extending on opposite sides of the tungsten _ Heretofore, in high wattage lamps of the type wherein the ?lament comprises a number of coiled segments arranged substantially parallel to each other, it has been the practice to wind the ?lament with extra coiled segments, at the 10 ends thereof which were short-circuited by in serting a mandrel therein and then welded to- \gether with their mandrels to the leading-in conductors. Such a joint has the disadvantage that the mandrel may not make a positive con 15 tact with some of the turns of the end segment so that those turns are heated by the current passing through the lamp thereby increasing the e?ective length of the ?lament over its designed 20 length. hMoreover, the welding operation tends to make the tungsten ?lament brittle so that it ?lament It. The leads are held in rigid spaced relationship by cross-bars |‘|-l8 of insulating material, preferably a ceramic material such as siliminite. The cross-bar I1 is secured to the leads M-M by short lengths of wire l9—l9 threaded through holes in the ends of the cross bar and in the leads and welded to the leads. The cross-bar I8. is secured to the ends of the 10 lead extensions I5-—I5 by similar wires 20-40 welded to said extensions. The ?lament l6 illustrated in the drawing is' of the biplane type comprising a plurality of _ parallel coiled segments. joined by upper and 15 lower uncoiled or bight portions 2| and 22 re spectively, the alternate segments in this case being located in separate planes so that one-half ' of said segments are in one plane and the other half of said segments are disposed behind said 20 ?rst half in another plane. "The ?lament is sup ported at the top by support wires 23 having is liable to break off if the lamp is jarred. hooked lower ends engaging the upper bights 2| One of the objects of‘my invention is to pro and secured at their upper ends to the cross-bar vide an improved form of joint betweenv the ?la H. The lower bights 22 are rigidly secured, pref- 25 ment and the leading-in conductors. Another 2 erably by welding, to the upper ends of anchor object is to provide a joint in which the end seg wires 24, the lower ends of which are rigidly se ments of the ?lament are effectively short-cir cuited. Still another object is to greatly increase cured to an insulating bridge member 25 which the strength of the joint and to provide a good may be made of zircon. The said anchors may be embedded in the bridge25. Each of'lgulde 30 30 mechanical and electrical connection of the ?la wires 26—26 has one end secured to the bridge ment to the leading-in conductors. 25 and the other end loosely coiled around. a lead Further objects and advantages of my inven tion will appear from‘the following description of extension l5 so as to be freely slidable thereon’ a species thereof and from the drawing in which so that the ?lament I6 is free to expand in a longitudinal direction‘and the bridge 25 moves 35 Fig. 1 is an elevation of one form of incandescent therewith but is prevented from rotatingby the lamp embodying my invention; Fig. 2 is an eleva said guide wires 26 thereby preventing the seg tion, partly in section and on an enlarged scale, ments of the ?lament from twisting. The bridge_ of a portion of the ?lament joint; and Fig. 3 25 is further guided by a wire 21 secured thereto is a section along the line 3-3 of Fig. 1 showing and extending through a hole in the cross-bar l8. 40 a portion of the ?lament and its supporting struc Each end of the ?lament I6 is wound with a ture. Referring to the drawing, the lamp shown coiled segment 28 (Fig. 2) over which is screwed therein comprises a glass bulb l0 having a base a coil 29, preferably of tungsten wire, of substan» construction of the type shown and claimed in tially the same length as the said segment 28 to short-circuit the said segment. The coil 29 is 45 United States Patents Nos. 1,967,852 and 2,069, 45 638, D. K. Wright, and consisting of a pressed of the same pitch as the segment 28 and prefer glass cup portion ll having tubular bosses l2—-l2 ably is‘made of a wire of slightly smaller diam thereon to which are sealed metal thimbles eter. A conductive support or mandrel 30 ex l3-|3 which serve for mounting the lamp ‘and tends through the segment 28 which is securely for conducting current thereto. Channel-shaped - held between a hooked end 3| of the mandrel 50 50 metal supports or leading-in conductors l4—l4 and the cross-bar H, the said mandrel extending are secured at their ends within the thimbles through a holein'said cross-bar and being se |3—-l3 and extend into the bulb Ill. The leads l4-I4 may be made of nickel-plated steel and 55 may be provided with rod or wire, end portions cured, preferably by welding, to the lead It. The hook 3| on the end of mandrel 30 may be omitted - if desired sincethe segment 28 grips the’ mandrel 65 2 2,134,574 quite tightly. Such a joint adds greatly to the having a coiled end portion, a coil screwed over strength of the lamp, provides a good mechanical said coiled end portion of said ?lament and short and electrical connection of the ?lament to the circuiting the turns thereof, and a conductive leads and assures the short-circuiting of all 01' mandrel in contact with and extending through the turns in the ?lament end segments 28. said coiled end portion or said ?lament and 5 What I claim as new and desire to secure by through Said cross-bar $0 One 01’ Said leads. Said Letters Patent of the United states is; ?lament end portion and the coil thereon being 1. In an incandescent lamp, the combination securely held between said cross-bar and the end of a conductive lead, a ?lament having a coiled end portion, a coil screwed over said coiled end of said mandrel- ‘ 3- In an incandescent lamp. the combination 10 portion of said ?lament and short-clrcuiting the 0f a ?lament, a‘conductive support for Supplying turns thereof, and a conductive mandrel in contact with and extending through said coiled end current to said ?lament, said ?lament having a coiled end portion surrounding and making elec trical contact with said supportI and a coil screwed over said coiled end portion of said ?lament and 15 portion of said ?lament and secured to said con- ductive lead at a point removed from‘said coils. 2. In an incandescent lamp, the combination 01’ a pair of spaced conductive leads, an insulating cross-bar extending between said leads, a ?lament short-circuiting the turns thereoi’. . EMMA B. PINKLE.