US2497566A

US2497566A - Mount structure for electric lamps

Info

Publication number: US2497566A
Application number: US90012A
Authority: US
Inventors: Joseph E Stone; John O Geissbuhler
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1949-04-27
Filing date: 1949-04-27
Publication date: 1950-02-14
Anticipated expiration: 1967-02-14
Also published as: GB678037A; FR1016483A

Description

Feb. 14, 1950 J. E. sToNi: ETAL 2,497,566

MOUNT STRUCTURE FOR ELECTRIC LAMPS Filed April 27, 1949 Inverfirws: Joseph E. S-lrone, John O. GeissbuhLeT". b5 62 Their A trtorheg.

Patented Feb. 14, 1950 2,497,566 MOUNT STRUCTURE FOR ELECTRIC LAMPS Joseph E. Stone, Cleveland Heights, and John 0. Geissbuhler, South Euclid, Ohio, assignors to General Electric Company, a corporation of New York Application April 27, 1949, Serial No. 90,012

3 Claims.

This invention relates to electric incandescent lamps in general, and more particularly to a mount construction therefor.

There are many so-called rough service applications where an electric incandescent lamp is subjected to considerable vibrations, jars or impacts, for instance in locomotive headlights, automatic mining machinery, earth moving equipment, tractors and other like equipment. In such cases, it is highly important that the filament or light source of the lamp be so supported that the forces developed by the vibrations or shocks be sumciently dissipated in order to prevent distortion of the hot filament such as is apt to-result in premature breakage or failure of the filament with consequent short lamp life.

It is an object of our invention therefore to provide an electric incandescent lamp having it filament so supported as to avoid detrimental effects of lamp vibration or impacts.

Another object of our invention is to provide an electric incandescent lamp having a flexible mount structure of simple form and which will effectively withstand vibration and impacts to whichthe lamp may be subjected in service.

Further objects and advantages of our inven tion will appear from the following description of a species thereof, and from the accompanying drawing. v

In the drawing, Fig.1 is a sectional view of an electric incandescent lamp according to the invention, and Fig. 2 is an enlarged perspective view of the mount structure thereof} Inaccordance with the invention, the filamentsupporting end or section of'an electric incandescent lamp mount is rendered flexible in all directions by making the lead-in wires or inleads of springy material and' forming them, inwardly of the lamp envelope, with laterally extending and approximately opposed arcuate intermediate portions, of more or less semicircular shape, which act as a cushion between the upper filament-supporting end of the mount and the lower anchored end of the mount to absorb any shocks or vibrations to which the lamp may be subjected in service. 1 7

Referring to the drawing, the invention is there shown as applied to an electric incandescent lamp of the sealed beam type. disclosed in U. S. Patent 2,148,314, D. K. Wright. and comprising a sealed glass envelope or bulb l consisting of preformed pressed glass reflector and cover glass sections {2 and 3, respectively, sealed together at their peripheries by fusion, as indicated at 4. The inner surface 5 of the reflector section 2 is formed either of paraboloidal shape as shown, or of any other desired optical shape, and is provided with a reflecting coating 6 of aluminum, silver or other similar light-reflective material.

Cal

Mounted on the rear outer side of the reflector section 2 at the region of the apex or center thereof is a base structure 1 of the general type shown and described in U. 8. Patent 2,272,- 512, Cotman, and comprising a pair of terminal contacts 8-8 in the form of metal straps or lugs which are suitably fastened, as by solder ing for instance, to the closed nippled ends 9 of respective metal ferrules or thimbles Itll. The contact lugs 8-8 are provided with screw terminals "-41 for connecting current supply wires thereto. The ferrules ill-I0 are formed of a suitable metal which will readily wet and adhere to the glass of the reflector section 2 and they are provided with skirt portions I! which are feathered to knife edges embedded and fused in the glass of the reflector section 2 around respective openings or passageways l1 through the wall thereof. The envelope l is provided with an exhaust tubulation l4 communlcating with the interior of the envelope through an exhaust opening I5 in the envelope wall at the apex of the reflector section 2. After exhaustion of the envelope through the tubulation it and. if desired, introduction of a suitable gas filling such as nitrogen or argon, the tubulation H is sealed or tipped-oil as indicated at I6.

Mounted within the envelope l and supported solely from the metal ferrules Ill-40 in spaced relation to'the envelopewalls is a lamp mount structure 11 according to the invention and comprising a pair of wire inleads l8--l8 secured and anchored at their outermost ends within the nipples 9 of the ferrules, as by solder l9 as shown. The inleads I8 are made of any suitable spring material, such as molybdenum or hard nickel for instance, which will not-lose its temper or springy character when heated to high temperatures such as are encountered during the operation of the lamp. From the ferrules l0l0,'the inleads l8l8. extend in more or less parallel spaced relation through the openings I3-I3 in the wall of the reflector section 2 and into the envelope l where they are connected, at their innermost ends, to opposite ends of a filament 20 preferably formed of tungsten wire. In the specific case illustrated, the filament 20 is composed of two convergent coiled sections or segments joined by a bight or loop portion 2| to form a V-shaped filament approximately lying in the plane of-the parallel extending portions of the inleads and mounted in the envelope l symmetrically about the optical axis of the reflecting surface 6 and approximately centered atthe focus thereof, with the apex of the V pointing forwardly as shown and with the plane of the filament lying approximately in the reflector axis. The connection of the filament ends to the inleads l8-I8 may be through small metal connecting lugs 22 suitably fastened to the inner ends of the inleads, as by welding, and provided with U-clamps 23 within which the free ends of the filament are clamped as shown in Fig. 2. The filament 20 is additionally supported at the bight 2| thereof by an anchor or support wire 24 provided at one end with a hook 25 within which the filament bight 2| is hooked. The other end of the support wire 24 is suitabl fastened in place on an insulated part of the mount structure in a manner to be hereinafter described.

In accordance with the invention the inleads l8-l8, inwardly of the envelope I, are formed with laterally bent approximately opposed arcuate or curved intermediate portions 28-28 which lie approximately in a common plane transverse to the generally parallel extending outer and

inner co-planar portions

21 and 28, respectively, of the inleads I 8-l8. As shown in Fig. 2, the arcuate portions 26 of the inleads are approximately in the shape of opposed semi-circles located on opposite sides of the common plane of the inleads and opening or facing toward each other and having a diameter somewhat less than the spacing of the outer portions 21-21 of the inleads, with the diametral chords of the semicircles (i. e., the imaginary lines joining the opposite ends of the semi-circles) lying approximately in the common plane of the outer and inner

parallel portions

21 and 28 of the inleads. These arcuate intermediate portions 28-28 of the inleads, being free of or spaced from the walls of the envelope and being made 01' a springy material,v therefore impart flexibility in substantially all directions (i. e., 360 solid angle) to the filament-supporting end 01' the mount I'I whereby any vibrations or shocks to which the lamp may be subjected in service are effectively absorbed or cushioned by such yielding intermediate portions. 28. I

To maintain the points of support of the filament in fixed relation to each other at all times independent of any unitary movement thereof due to lamp vibration or shock, the inner portions 28-28 of the inleads i8-l8 are rigidly tied togather and held in parallel relation by suitable insulative tie means which, in the particular case shown, comprises a pair of spaced cross-bars or

bridges

29 and 30 each consisting of a short length of glass rod 3| having support wires 32 wall and connected at their inner ends to said embedded in and projecting from its opposite ends. The

cross-bars

28, 30 are secured to the inner portions 28-28 of the inleads, at spaced points therealong, by suitably fastening the support wires 32 thereto, as by welding for instance. The intermediate support wire 24 for the filament 28 is embedded and anchored in the glass rod 3| of the innermost cross-bar 29, thus maintaining the intermediate support point for the filament in fixed relation to the end supports thereof at all times. The mount structure I! according to the invention therefore includes as a part thereof a filament-supporting section or unit, comprising the inner portions 28-28 of ,the inleads, the

cross-bars 29, 38 and the intermediate support wire 24, which holds the filament 28 in proper relation at all times and which is capable of moving as a unit, withoutrelative movement between the filament and the adjacent supporting parts of the said unit, during vibration or other sudden movement of the lamp.

From the foregoing it will be evident that the mount structure l1 comprising .our invention provides a simple and effective flexible supporting arrangement for the filament whereby any vibrations, jars or impacts to which the lamp may be subjected in service are readily absorbed by the yielding arcuate intermediate portions 28-28 of the inleads which act as an elastic connection or cushion between the inner or filament-supporting section of the mount and the outer or anchored section of the mount to efiectively minimize distortion of the hot filament by such lamp vibrations or shocks, thus rendering the entire lamp structure especially useful for rough service applications such as a locomotive headlight or as a lighting unit for automatic mining or earth moving equipment, tractors and other similar equipment where the lamp is ordinarily subiected to unusual shock or vibration.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electric incandescent lamp comprising an envelope, a filament in' said envelope. inleads anchored to and supported from the wall of said .envelope and extending into the envelope from .rigidly tying the inner end portions of the inleads together, said inleads being provided intermediate their anchored ends and their said bridge means with laterally extending curved portions each approximately located in a plane transverse to the inleads and spaced from the envelope wall to impart flexibility to the said inleads.

, 2. An electric incandescent lamp comprising an envelope, a filament in said envelope, inleads anchored to and supported from thewall of said envelope and extending into the envelope from their wall anchorages in the same. general direction and in spaced relation to the envelope filament, and bridge means 'insulatively and rigidly tying the inner end portions of the inleads together, said inleads being provided intermediate their anchored ends and their said bridge means with laterally extending approximately opposed arcuate portions each approximately located in a plane transverse to the inleads and spaced from the envelope wall to impart flexibility to the said inleads.

- 3. An electric incandescent lamp comprising an envelope, a filament in said envelope, inleads anchored to and supported from the wall of said envelope and extending into the envelope from their wall anchorages in the same general direction and in spaced relation to the envelope wall and connected at their inner ends to said filament, and bridge means insulatively and rigidly tying the inner end-portions of the inleads together, said inleads being provided intermediate their anchored ends and their said bridge means with laterally extending opposed arcuate portions of approximately semicircular shape approximately located in a common plane transverse to the inleads and spaced from the envelope wall to impart flexibility to the said inleads.

, JOSEPH E. STONE.

- JOHN. O. GEISSBUHLER.

No references cited.