US1936762A - Illuminating device - Google Patents

Description

Filed May' 14, 1929 2 Sheets-Sheet 1 i K INVENTOR BY A m 1-. j g, A ORNEYS Nov. 28, T933. R. HOWE 1,936,762

ILLUMINATING DEVICE Filed May 14, 1929 2 Sheets-Sheet 2 INVENTOR Patented Nov. 28, 1933 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to illuminating devices and with particularity to high powered lamps.

The invention has for its principal object to provide a high powered lamp which is capable of '5 carrying very large currents without deterioration of the elements and-supports within the lamp.

Another object of the invention'is to provide a high poweredlamp which is suitable for photographic purposes, or for any purpose where light of great intensity is required.

While lamps of the glowing filament type have been used for a number of, years for photography, signaling, etc. it has been found that because of the structure, weight and arrangement of the filament, together with the fact that the filament must necessarily be operated at an extremely high temperature, great care must beexercised in the manner of supporting the glowing elements.

Accordingly it isone of. the principal features of this invention to provide anovel method of supporting a concentrated coiled filament within an evacuated container or envelope, whereby the excessive temperatures of the glowing element exert substantially no deleterious effect on either the lead-in wires or the filament supports.

Another feature of the invention resides in the manner of bracing the filament supports of a high powered lamp in such a way that the weight of the filament and-associated parts is incapable of bending or breaking said supports while the lamp is being operated at high temperatures.-

A further feature pertains to the manner of supporting a concentrated filament having substantial weight, within an evacuated container, whereby the filament is enabled to expand and contract within very wide limits, without destroying any of the filament supports.

A further feature of the invention resides in a high powered lamp of the glowing filament type, wherein the filament may be supported within the lamp with a minimum of joints in the supporting elements.

A still further feature pertains to a base for a high powered lamp, which base is capable of selfadjustment without breakage, in accordance with I the expansions and contractions of the lamp envelope.

I, Another feature pertains to the organization ,and arrangement of elements which go to make up a high efliciency, high power lamp, which is of maximum durability and is free from breakl age, due either to the high temperatures at which the lamp operates, or due to vibration during handling, shipping, etc.

Referring to the drawings;

Fig. 1 shows a front view of a high powered lamp constructed according to the invention, 0 witha portion of the envelope broken away;

Fig. 2 is a side View of the lamp shown in Fig. 1, with the envelope removed;

Fig. 3 is a View showing the arrangement of the lead-in wires; I I I Fig. 4 is a detail view of the manner of uniting the filament supports;

Figs. 5 and 6 are detail views showing th manner in which the filament is supported at the top; I

' Figs. 7 and 8 are detail views of the manner of supporting the lower end of the filament;

Figs. 9 and 10 show a modified manner of supporting the top part of the filament;

Fig. 11 shows a modified manner of mounting and anchoring the filamentsupporting block;

Fig. 12 illustrates another way in which the filament I supports may be braced with each other.

Referring more particularly to Figs. 1, 2 and 3, the numeral 1 represents an evacuated envelope which may be of any well known shape, but is preferably so formed that the portion containing the glowing electrode 2 is spherical in shape and sufiiciently large with respect to the filament, to prevent the temperature of the filament destroying or deteriorating the envelope wall. For this purpose it is preferred to form the envelope 1 out of pyrex glass or any other highly refractorytransparent medium. The lower portion 3 of the envelope is substantially cylindrical and constricted, and is provided with a reentrant portion 4, having projections 5, 6, 7 and 8 formed integrally therewith, and within which are sealed the flead-in and filament support wires 9, 10, l1 and 12, While any well known manner of sealingin the lead wires may be employed, it is preferred to use lead-in'wires of a material having substantially the same coefiicient of expansion as the material of the envelope 1, or of the projections 5, 6, 7 andS. It has been found that tungsten rods or wires serve particularly well for this purpose.

As represented in Figs. 1 and 2, the filament supports are arranged in two lateralsets 9, 11 and 10, 12, respectively and the rods of each set, for example, rods 9 and 11 are bowed outwardly from each other and cross each other at, or near the point 13, as shown more clearly in Fig. 2. At the point of crossing, these rods may be integrally united by a weld or even permanently fastened together by means of an additional piece of wire, or any other equivalent fastening means or they may be even twisted around each other. As shown in Fig. 2, each set of rods, for example the left hand set 9 and 11, after crossing, diverge from each other, and are continued upwardly as shown, into the spherical portion of the envelope, and then converge between each other and cross at the point 14. I

As shown more clearly in Fig. 4, one of the rods of each set, for example the rod 11, has a portion 16 bent at substantially right angles, and continues into the filament support block 15. The end of the associated rod 9 at the point of crossing 14, is welded to the rod 11 and terminated at the weld. If desired, the end of the rod 9 may be given one or more turns around the rod 11, as shown in Fig. 4, prior to welding, or if desired, reliance may be placed entirely upon the twisting of the rods to prevent displacement. The right hand set of rods 10 and 12 are extended upwardly from the press projections 8 and 8 in a similar manner to the rods 9 and 11. Thus as shown in Fig. 4, the rod 12 continues on into the block 15, while the associated rod 10 is twisted around the rod 12 at the point of crossing, and may be welded thereto as described in connection with rods 9 and 11. The block 15 is of any suitable highly refractory and insulating material. It has been found that zirconia serves particularly well for this purpose because of the exexcessive temperatures encountered in the lamp when in operation. The ends 16 and 1'? of the wires 11 and 12 respectively, are fused into the ends of the block 15in any convenient manner, in order that a rigid joint may be provided with the block. It is preferred to provide the portions 16 and 17 of the rods with enlarged ends 18 and 19 (Fig. 5) which may be positioned within the block 15 when the same is in a semi-molten condition. 7

Each set of rods 9, 11 and 10, 12 are rigidly spaced at their bowed portions by means of the bridge members 20, 21, which are preferably formed of tungsten and welded to the associated rods. If desired the ends of the bridge members may be given one or more turns around the filament supports prior to welding.

The above described arrangement provides two lateral and parallel supporting frames which are rigidly united at their upper end by means of the insulating block 15. Disposed between the opposite frames is the filament 2, which is preferably of coiled tungsten and formed into the shape shown in Fig. 1. While this figure shows the filament as made up of four serially connected coil sections, it will be understood that any number of sections may be employed, and these sections may be connected in parallel if desired.

In order that the filament may be centrally located and supported between the frame members, the ends of the two central coiled sections 22 and 23 are bent upwardly to provide a loop 24, and similar loops 25 and 26 are provided at the lower ends of the coiled sections. As shown more clearly in Fig. 2, the opposite ends 2'7 and 28 of the spirally connected coils are bent at right angles to the coils, and are extended to the bridge members 20 around which they are twisted and welded, if desired.

' For the purpose of supporting the central sections, the block 15 has wrapped around its central portion a metal strap 29 which, as shown in detail in Fig. 6, has its free ends formed in hook fashion, and with one end 30 overlapping the other end 31 to prevent the ends from separating, due to the high temperatures at which the lamp is operated. The hook portion of the strip 29 engages the loop 24 of the filament and provides a strong support therefor. The purpose of making the member 29 of relatively wide strip material is to distribute the weight of the filament material over as large an area of the block 15 as possible, since it has been found that where the filament is supported merely by a rod or wire extending around the block that the said block, because of the high temperature, has a tendency to crack at the point of support.

Similarly for the purpose of anchoring the lower end of the filament there is provided a block of insulation 32, which is preferably of zirconia or similar refractory material, and this block is supported on the bridge members 21 by means of the laterally extending rods 33 and 34, which are fused at one end into the block 32 and at the opposite end are welded onto the bridge members 21.

As shown more clearly in Figs. 7 and 8, a strip of metal 38 is formed around one end of block 32, and has its free ends 36 and 37 curved to the shape shown in Fig. 8, and overlapping. A similar strip of metal is provided at the other end of the block 32. The loops 25 and 26 are slipped in between the overlapped edges of the strips 35 and 38 respectively, and thus allow the filament to expand and contract without permitting the filament to come in contact with the main supporting framework.

For the purpose of properly supporting the assembled lamp, there is provided a base 39 (Figs.

1 and 2) which may be of pressed steel, brass or other suitable material. The lower portion of the base which receives the end of the lamp is cup-shaped, and is provided on opposite sides with discs of insulating material 40 and 41, which may be of asbestos, asbestos board or similar heat resisting material. Each of the discs is provided with a set of four holes which register with corresponding holes in the bottom 42 of the base, and the discs are clamped to the bottom 42 by suitable bolts 43 and nuts 44 on opposite sides thereof. The unthreaded portions of the bolts 43 extend downwardly and provide contact prongs whereby the lamp may be inserted in a $23 suitable receptacle. Flexible copper leads 51 are then fastened to the upper ends of the members 43 and connected to the rods 5, 6, 7 and 8, where they emerge from the pressed portion.

As shown in Figs. 1 and 2 the bottom as of 138 the base is provided with an upwardly extending portion 45 which terminates in a split ring portion 46, which also surrounds the constricted portion of the lamp. The ends of the split ring portion overlap each other, and thus provide a semi-resilient support for the lamp, enabling the lamp to tilt in either direction or to expand without damage to the envelope. If desired the overlapping ends of the ring portion 46 may be provided with cooperating lugs to prevent disen- A! gagement thereof due to excess movement of the lamp in the base. A layer of asbestos or other similar packing is provided between the metal parts of the base and the glass as indicated by numeral 52.

From the foregoing it will be seen that there is provided a lamp structure which is capable of being operated at exceedingly high temperatures, and that the filament is supported with a p truss-like structure, and that the main portion of this structure is removed from the destructive temperature field of the filament. Furthermore each leg of the filament support is throughout its length, formed from the same material, and the only joints required are where the ends 16 and 17 (Figs. 4 and'5) are united to the block 15.

Thus a continuous piece of material is used for the seal-in and filament supports, obviating the use of welds'which have been found to be subject to a great deal of breakage due to the temperature and weight of the glowing filament.

Referring to Figs. 9 and 10 there is shown a modified manner of supporting the filament on the block 15. In this embodiment the block 15 is provided with an opening 4'? through which passes the filament supporting hook 53. The upper surface of block 15 is provided with a metal cap 48 to which the hook 53 is united, preferably by welding, and indicated by the numeral 49.

Fig. 11 shows another manner of supporting the lower block 32 on the frame members. In this embodiment the bridge members 21 may be dispensed with and the projections 33 and 34 may connect with diagonally opposite legs is and 11 of the framework. In order that the block may be positioned centrally within the filament supporting frame, the rods 33 are preferably fashioned in the shape shown in Fig. 11, although any other manner of centrally supporting the block may be employed.

Fig. 12 shows a modified manner of forming the side frame members. In this embodiment the legs 9 and 11 for example, instead of crossing at their lower ends may be crossed at their middle portions, and partially twisted around each other, as indicated by the numeral 50, where they may be welded if desired.

While specific structures and apparatus have been disclosed in the foregoing, it will be understood that the invention is not limited thereto, and that changes may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. In an illuminating device an evacuated envelope having a reentrant base, a luminous element within said envelope, and means for supporting said element, including a plurality of rod sets of highly refractory material each rod supported at one end in the base, said rods of each set converging towards each other within the envelope, and being rigidly fastened together at the point of convergence, said rods also serving as lead-in conductors.

2. In an illuminating device having an envelope with a base portion, a filament, and two sets of supports for supporting said filament each set including a pair of rods united at opposite 'ends, and bowed outwardly and crossing each other intermediate said ends, the lower ends of said crossed rods being sealed into said base.

8. An illuminating device according to claim 2, in which the filament is supported at its center from said supporting means between the bowed portions thereof.

4. In an illuminating device an evacuated container having a base portion, a filament and means for supporting said filament comprising a rod supported at one end in the base of said envelope, and another rod supported at one end at a different point in said base, both of said rods converging towards each other, and being united at a plurality of points throughout their length.

5. In an illuminating device, the combination of an evacuated envelope, a filament, a plurality of frame members for supporting said filament, each comprising a set of rods extending upwardly from the baseof said envelope, the rods of each set being united at their upper ends and at a point intermediate their ends, the rods diverging from each other intermediate the points of union, a tie member niting the rods of each set at the said diverging portions thereof, said filament being supported from said tie members.

6. In an illuminating device of the glowing filament type, means for supporting the filament for free expansion in all directions, comprising two laterally disposed frames, each frame comprising a plurality of rods united at separated points and bowed outwardly from each other intermediate the points of union, one rod of each frame having one end bent at right angles to the main body portion thereof, and a refractory insulator block rigidly uniting the said bent ends.

'7. In an illuminating device having an envelope with a reentrant base portion, a coiled filament and means for supporting said filament at more than two points in said base, and comprising two sets of rods, the rods of each set being welded to each other at points near the ends thereof, and separated from each other throughout their length intermediate said welds, the lower ends of said rods being sealed into said base.

8. In an illuminating device having an envelope with a base portion, a coiled rod filament, means for supporting said filament at three or more points in said base, and comprising two sets of rods, the rods of each set crossing and welded to each other at a point sufliciently far removed from the filament to prevent the weld being destroyed by the filament heat, a block of refractory insulating material rigidly uniting the ends of said rods, and a filament suspension member carried by said block.

9. In an illuminating device a filament in the form of connected coil sections, a filament support frame comprising a plurality of sets of rods, the rods of each set being united by a tie member, an insulating block rigidly uniting the ends of each set of rods, means carried by said block for supporting the central sections of the filament and means for supporting the endsections of the filament on the oppositely disposed tie members.

10. A filament support for incandescent lamps comprising a block of refractory insulating material, a metal strap passing around said block, the free ends of said strap being formed in hook shape, and overlapping each other, a plurality of 130 pairs of rods to which said block is attached, the lower ends of said rods forming a four-point support for the filament assembly.

11. In a high powered incandescent lamp, a filament composed of a plurality of adjacent 135 coiled sections, a plurality of filament support frames, and a block of refractory insulating material between said frame members at opposite ends thereof, each of said frames comprising a pair of crossed wire rods welded to each other 145 at their point of crossing.

12. In an incandescent lamp, a filament, filament support frames laterally disposed with respect to said filament, said frames being united at opposite ends by refractory insulating blocks, 345 a strap surrounding the upper block and having a hooked portion for engaging the filament, a plurality of spaced straps surrounding the lower block, each having a portion for engaging the filament and retaining it centrally between said 150 insulating block uniting the upper ends of each frame and on which a portion of the filament is supported, another insulating block for guiding the lower portion of the filament and centrally mounted between said frames.

14. An incandescent lamp according .to claim 13 wherein said other block is supported from diagonally opposite frame-rods.

RAYMOND HOWE.

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