US3267275A

US3267275A - Incandescent lamp and fixture

Info

Publication number: US3267275A
Application number: US326860A
Authority: US
Inventors: Ernest E Kendall; Robert J Mcintyre
Original assignee: Sylvania Electric Products Inc
Current assignee: GTE Sylvania Inc
Priority date: 1963-11-29
Filing date: 1963-11-29
Publication date: 1966-08-16
Anticipated expiration: 1983-08-16
Also published as: DE1917435U

Description

1966 E. E. KENDALL ETAL 3,267,275

INCANDESCENT LAMP AND FIXTURE Filed Nov. 29, 1963 ERNEST E. KENDALL ROBERT J, M INTYRE INVENTORS FIG.3

AT RNEY Patented August 1%, liinifi 3,267,275 INCANDESCENT LAMP AND FEXTURE Ernest E. Kendall, Peabody, and Robert .l. Mclntyre,

Gloucester, Mass, assignors to Sylvania Electric Products Inc., a corporation of Delaware Filed Nov. 29, 1963, Ser. No. 326,36) 6 Claims. (Cl. 24tlll.2)

This invention relates to tubular type incandescent lamps and particularly to positioning of such lamps in a fixed and vibration-free position.

Tubular type incandescent lamps are known to the art, however, the type to which our invention has particular applicability is the so-called quartz-iodine lamp in which a tungsten filament is axially disposed within a tubular, quartz envelope containing iodine.

Heretofore when electrical connections for such lamps were made, it was common practice to slip slotted, cylindrical, refractory sleeves around press seals formed at the ends of the envelope. Cements were then used to secure the sleeve to the glass. The outward ends were fitted with socket-type electrical contacts and cooperating springbiased, ball joints were used in the fixture.

We have now found that in installations where the lamps are subjected to high impact and shock forces, that such fixtures and lamp fittings are not wholly satisfactory. The lamp can rotate about its axis in the fixture and sometimes become dislodged. Because of a residual exhaust tube tip, such rotation can change the lamps lighting characteristics. Frequently the combination of vibration and rotation can cause the cement which holds the sleeve on the seal to crack and such cracking can break the electrical connection. Furthermore when the ball and socket-type construction was used in outdoor installations, oxidation sometimes ruined the electrical connection between the fixture and the lamp.

According to our invention, we dispose a hollow, cylindrical metal connector having a slotted end on each of the press seals. The connector is anchored to the seal by extending the lamps lead in wires through the base and soldering them to the metal. Preferably the entire connector is filled with solder to add permanence to the structure. A groove is machined into each of the cylindrical connectors so that rotation-free positioning will be assured in the fixture. The fixture in which the lamp is placed includes a spaced pair of opposing spring clips, each of the clips having a detent formed on one of the legs.

Accordingly, the primary object of our invention is rotation-free and uniform mounting of tubular incandes cent lamps in fixtures.

The many other objects, features and advantages of our invention will become manifest to those conversant with the art upon reading the following specification when taken in conjunction with the accompanying drawings wherein preferred embodiments of our invention are shown and described.

Of these drawings:

' FIGURE 1 is a top plan view of the lamp fixture with the tubular incandescent lamp disposed therein.

FIGURE 2 is a front elevational view of the fixture and lamp shown in FIGURE 1 with a portion of the lamp and the fixture cut away.

FIGURE 3 is an enlarged cross-sectional view, taken along the line 3-3 of FIGURE 2, illustrating the relationship of the lamp in the fixture.

Referring noW to FIGURE 1 of the drawing, the lamp 1 comprises a tubular, quartz glass envelope with an incandescent filament 2 disposed axially therein. Usually the filament is supported upon lead-in wires 3 and 4- which are connected through press-

seals

5 and 6 to the power line through the intermediary of the fixture elements.

Enclosed within the envelope is a fill including a quantity of iodine and hence, the lamps are called iodine-quartz lamps.

Incandescent lamps having quantities of iodine in the envelope are known to the art. Such lamps operate on a tungsten-iodine cycle which is a regenerative, continuing process in which tungsten iodine is produced when the iodine combines chemically with particles of tungsten evaporating from an incandescing tungsten filament. Subsequent thermal decomposition of this compound replaces the tungsten particles on the filament. In conventional filament lamps not containing controlled quantities of iodine, these particles are deposited on the envelope, thus generally causing a loss of light output due to blacle eningj Rupturing of the filament may occur when a suflicient quantity of tungsten particles evaporates and the lamp must be replaced. However, the iodine-tungsten cycle eliminates lamp blackening and reduces lamp outage by its getter action.

The iodine, together with the heat of the lamp, prevents the tungsten from accumulating on the lamp envelope and darkening it. As the vaporized tungsten iodide circulates back into the area of the incandescent filament, the intense heat of the filament frees the tungsten from the tungsten iodide by thermal decomposition and this tungsten is deposited back on the filament leaving the iodine free to begin a new cycle. Theoretically, if the evaporating tungsten particles could be returned to the filament in a perfectly even coating, the lamp might never burn out. But since there is no way to control exactly where the tungsten particles return to the filament, one spot will eventually wear out, thus rendering the iodinequartz lamp inoperative. This condition, however, occurs after operation in the order of hundreds of hours and possibly even thousands of hours before lamp failure. Furthermore, during the life of an iodine lamp, the maintenance of light output is substantially constant.

The press-

seals

5 and 6 are formed by heating the ends of the tubular quartz envelope while the lead-in wires attached to the filament 2 are disposed therethrough.

Although not shown in this figure, the lead-in wires have an intermediary molybdenum foil section welded thereto so that a tight metal to glass seal can be made. When the glass is sufficiently plastic, the walls are pressed together and allowed to cool. The seal which is formed is fiat and is preferably designed to have raised or thickened edges which makes the envelope more resistant to breakage. Furthermore the use of thickened edges can help to prevent lateral movement of the lamps electrical contact.

Slipped over each of the

press seals

5 and 6 and b tween the thickened edges, are

cylindrical metal connectors

7 and 8 which are attached to the lead-in wires 3 and 4 respectively. Preferably the diameter of the cylinder is substantially equal to the width of the flat portions of the press seal between the raised edges. The hollow cylindrical connectors have slots on each side thereof, so as to form legs which may conveniently fit of each side of the seal. Preferably the width of the slot is just slightly greater than the thickness of the fiat portion of the seal so that the assembly can be made rugged.

The

cylindrical connectors

7 and 8 are pressed into the resilient clips which are formed in a general U-shape, the legs of the U being spring biased towards each other. Each of the legs are recessed inwardly and then bent outwardly to form a cylindrically shaped retaining portion which has the same general shape as the

cylindrical connectors

7 and 8. Preferably the tops of the clips are flared outwardly so that the lamp may be easily seated.

According to our invention, we form grooves 9 and having generally flat inner surfaces in each of the cylindrical contact elements, usually on opposite sides thereof. On each of the spring clips we form detents 11 and 12 into which the grooves will compatably fit. The use of the groove and detents will prevent rotation of the lamp in the fixture. The grooves are sufficiently wide that the detents will fit into them and the spring clips will snap closed and tightly fit around the connectors.

If the grooves are placed on opposite sides of the respective cylinders and the cooperating detents formed on the clips accordingly, uniform disposition of the contacts in the fixtures can always be attained and the bottom of the lamp can always be pointed downwardly.

The fixture upon which the lamp is mounted may be of any desired shape however we prefer to dispose a button-type fuse 13 between a pair of leaf-

type springs

14 and 15 so that if the lamp should fail, the fuse 13 will prevent short-circuiting. Electrical connections can be made at any convenient location upon the body of the fixture.

Referring now to FIGURE 2, the press-seals and 6 are shown with the lead-in wire assembly. The assembly includes the internal lead-in wires 3 and which extend into the envelope and have the ends of the filament 2 disposed thereon. As has been described briefly, welded to the lead-in wires are thin molybdenum foil sections 17 and 18 which in turn are connected to external lead-in

wires

19 and 22, the latter extending outside of the lamp. We prefer to use the above-described lead-in wire assembly because when cool, the quartz forms a tight seal about the molybdenum sections 17 and 18 and will not scale or break away.

As shown in the broken away section, the detent 11 extends inwardly into the generally cylindrical portion of the spring clip. The exact width of the detents is not critical so long as they are wide enough to support the lamp without bending and will fit into the corresponding groove of the connector.

When mounting the

cyindrical connectors

7 and 8 upon the press seals 5 and 6, we extend the external lead-in wires through the middle of the cylinder and then fill in the ends with solder, lead or similar metals. When the filling is hard, the

connectors

7 and 8 will be firmly attached by the legs on each of the press-seals and also anchored by the lead-in wires.

Through the use of a lamp having grooved connectors and a fixture with corresponding detents, the lamp can always be positioned uniformly with the exhaust tu-be tip 21 pointed downwardly where it cannot effect the light distribution pattern of the lamp.

Frequently as a further support, we dab small quantities of high temperature cement upon the press-seals so that even greater rigidity is obtained. After the legs of the cylindrical connectors are slipped over the press seals, the cement will harden, act as a filler and prevent any movement whatsoever.

As seen in FIGURE 3, the cylindrical connectors have a groove 9 into which fits detent 12 of the U-shaped clip. The remainder of the clamping portion or the U-shaped clip is cylindrically shaped to conform to the shape of the connector.

Lead-in wire 22 is disposed within the cylindrical connector 8 and preferably, although not necessarily, rests upon one of the walls to provide a better electrical connection. The cylinder is filled with lead, solder or similar metal 20 to insure permanence. Of course, it is equally possible to reduce the internal diameter of the cylinder to a point where the bore is just slightly larger than the external lead-in wire 22 and then spot weld the lead-in wire to the mouth of the hole.

It is apparent that many changes and modifications can be made within the spirit and scope of the instant invention but it is our intention, however, only to be limited by the spirit and scope of the appended claims.

As our invention we claim:

1. An incandescent lamp comprising: a tubular glass envelope having fiat seals disposed at either end thereof; a filament disposed within said envelope; means to conduct current from outside of said envelope into said filament, said means including lead-in wires extending outwardly from said seals; a generally cylindrical metal connector disposed at one end of said sealed envelope and a second generally cylindrical metal connector disposed at the other end thereof, each of said connectors having slots into which said press seals fit; a groove formed in each of said first and second connectors and disposed on opposite sides thereof; said lead-in wires extending inside of said cylinders and attached thereto and in electrical conducting relationship therewith.

2. The lamp according to claim 1 wherein each of the cylindrical connectors are hollow and said lead-in wires extend therethrough, the connectors being filled with a metal to secure the electrical connector and prevent relative movement.

3. The lamp according to claim 1 wherein said press seal has thickened edges and legs formed in said connectors are disposed directly upon the flat, central portion of said seal and between the thickened edges.

4. Incandescent lighting equipment comprising: a pair of spaced apart, U-shaped, spring biased clips, a portion of each of said clips having a generally cylindrical shape; a detent formed in each of said clips; an incandescent lamp comprising a tubular glass envelope having flat seals disposed at either end thereof; a filament disposed within said envelope; means to conduct current from said clips into said filament, said means including lead-in wires extending outwardly from said seals; generally cylindrical metal connectors disposed at either end of said sealed envelope, said connectors having slots into which said press seals fit, said slots forming legs in said connector; a groove formed in each of said cylindrical connectors and disposed on opposite sides thereof; said lead-in wires extending inside of said cylinders and in electrical conducting relationship therewith; a groove formed on each of said connectors; said detents being disposed in said grooves and the rest of the cylindrical portion of said clip being disposed about said connectors.

5. The equipment according to claim 4 wherein each of the cylindrical containers are hollow and said lead-in wires extend therethrough, the connectors being filled with a metal to secure the electrical connection and prevent relative movement.

6. The equipment according to claim 4 wherein the press seals of said lamp have thickened edges and said legs of said connectors are disposed directly upon the fiat central portion of said seal and between the thickened edges.

References Cited by the Examiner UNITED STATES PATENTS 1,909,632 5/1933 Prouty 33950 3,001,096 9/1961 Mosby 313318 3,001,097 9/1961 Smialek 3l33l8 3,156,841 11/1964 Ayres 313-318 X NORTON ANSHER, Primary Examiner.

C. R. RHODES, Assistant Examiner.

Claims

1. AN INCANDESCENT LAMP COMPRISING: A TUBULAR GLASS ENVELOPE HAVING FLAT SEALS DISPOSED AT EITHER END THEREOF; A FILAMENT DISPOSED WITHIN THE ENVELOPE; MEANS TO CONDUCT CURRENT FROM OUTSIDE OF SAID ENVELOPE INTO SAID FILAMENT, SAID MEANS INCLUDING LEAD-IN WIRES EXTENDING OUTWARDLY FROM SAID SEALS; A GENERALLY CYLINDRICAL METAL CONNECTOR DISPOSED AT ONE END OF SAID SEALED ENVELOPE AND A SECOND GENERALLY CYLINDRICAL METAL CONNECTOR DISPOSED AT THE OTHER END THEREOF, EACH OF SAID CONNECTORS HAVING SLOTS INTO WHICH SAID PRESS SEALS FIT; A GROOVE FORMED IN EACH OF SAID FIRST AND SECOND CONNECTORS AND DISPOSED ON OPPOSITE SIDE THEREOF; SAID LEAD-IN WIRES EXTENDING INSIDE OF SAID CYLINDERS AND ATTACHED THERETO AND IN ELECTRICAL CONDUCTING RELATIONSHIP THEREWITH.