US2691817A - Device for applying coiled filaments to setting mandrels - Google Patents

Description

Oct. 19, 1954 N. J. RAINONE ETAL DEVICE FOR APPLYING COILED FILAMENTS TO SETTING MANDRELS Filed Dec. 14, 1950 INVENTORS MI Efl/NO/VE GB MOP/T2 BY9 ATTORN blilmr Int I!!! i Patented Oct. 19, 1954 UNITED STATES ATENT OFFICE DEVICE FOR APPLYING COILED FILAMENTS TO SETTING MANDRELS Application December 14, 1950, Serial No. 200,844

Claims. (01. 29-284) This invention relates to apparatus for shaping filaments for incandescent electric lamps and the like and, more particularly, to means for applying coiled filaments to setting mandrels.

The principal object of our invention, generally considered, is to provide a device or loading fixture for holding the coiled lengths of a filament when bent into a plurality of side-byside segments, and provide a funnelling entrance for conveniently simultaneously receiving the mandrels of a jig on which said filament segments are heated to set them in proper relationship with respect to one another.

Another object of our invention is to devise a method for externally holding the several segments of each coiled length of filament, such as is used for projection and other high wattage electrical devices, in proper relationship with respect to one another, and then funnelling internal supporting means in place for holding said segments in proper relationship with respect to one another while being heat-treated to a temperature where they are set, so that upon removal they willremain spaced in the desired relationship.

A further object of our invention is to devise a fixture comprising blocks with internal depressions which provide, upon being placed in mating engagement, nests for holding the several side-by-side segments of a coiled length of filament in proper relationship with respect to one another, and funnelling grooves which properly guide mandrels into the interior of said segments, so that upon release from said blocks the segments are held in proper relationship with respect to one another and may be then heated on said mandrels to a setting temperature.

Other objects and advantages of the invention will become apparent as the description proceeds.

Referring to the scale drawing:

Figure 1 is an elevational view of one form of coiled and segmented filament with which our invention may be employed.

Figure 2 is an end view of the fixture for holding the coiled segments of. such a filament in position for application to the mandrels of a setting jig, the blocks forming said fixture being shown in release position.

Figure 3 is a sectional view on the line IIIIII of Figure 2, in the direction of the arrows.

Figure 4 is a view corresponding to Figure 2, but showing the blocks in mating engagement, with a segmented filament in place therebetween.

Figure 5 is a view corresponding to Figure 3, but showing the mandrels of a setting jig in the process of being guided into the several segments of a coiled filament held in the fixture.

Figure 6 is a view in perspective, showing the mandrels of a setting jig in place in the coiled segments of a filament, while held in the fixture.

Figure '7 is a View corresponding to Figure 2, but showing a filament between the blocks of the fixture, in the process of being released.

Figure 8 is a plan of a setting jig, showing a filament in place thereon.

The segments of coiled filaments for projection lamps, whether formed by hand or by machine, are after initial forming not sufficiently accurately aligned for use in lamps. By this we mean that the side-by-side segments of coiled lengths of filament, whether of the so-called monoplane or biplane type, which are commonly used in projection lamps and other high wattage electrical devices, are not formed accurately enough for use in such devices without some adjustment, either by hand or mechanically. If such segments are reshaped by hand with the aid of a pair of tweezers, the average production is low and the shrinkage high. The purpose of the presentiinvention is to eliminate hand adjusting and facilitate the application of such filaments to the mandrels on which they are held while being baked to a temperature at which the sections are set with respect to one another.

The jig upon which it is desired to place such filaments, one form of which is indicated at II in Figure 1, is illustrated in Figure 8. Filaments I I are each formed by bending a coiled length of wire into a plurality of side-by-side segments, staggered from one plane to a parallel spaced plane, forming two rows, with alternate segments lying in equally spaced planes parallel to one another and perpendicular to said first-mentioned spaced planes. In said figure, the refer ence character [2 designates mandrels, desirably of considerable length, formed of tungsten, and pointed at opposite ends as indicated at I3. One mandrel is provided for each section it of the filament, the present embodiment involving ten sections. These mandrels are such a size that they accurately fit the interior of the several coiled segments, so as to hold them in proper relationship with respect to one another when said mandrels are properly spaced by passing through apertures l5 in the preferably molybdenum spacer plates I6. In other words, the axes of apertures I5 in the spacer plates I6 are spaced to agree with the spacing desired between the axes of the sections M of each filaments ll.

It will be obvious that it would be difiicult and time-consuming to apply such a filament H directly to one mandrel S2 at a time of the jig ll, formed by said mandrels and spacer blocks It, as it would mean trying to get the, in the present nistance ten, mandrels in the corresponding number of separate apertures in the sections M, which apertures are not necessarily initially accurately spaced for the reception of such inandrels.

We have overcome this difiiculty by providing a fixture 28 for conveniently threading the segments of coiled filaments simultaneously and quickly upon such jig. Such fixture consists essentially of a nest with tapered entrance guides. Both of these features are formed in a pair of blocks i8 and I9, which are movable from release position, shown in Figure 2, to. mating position shown in Figure 4, along studs 2! and 22. Both of said studs are desirably, but not necessarily, fastened to one block, say that designated is, and the other block as formed with apertures 23 and 2d closely receiving said studs, so that the block 13 is accurately guidable therealong from a position separated from the block 13, to a position in mating engagement therewith. as illustrated in Figure 4,

One block, it for example, is formed with plurality of semi-cylindrical nesting grooves or do pressions 25, disposed parallel to one another and spaced the distance desired for the several segments one one side, of the coiled biplane filament l l. The other block it has a corresponding series of grooves or depressions 26 for similarly nesting the several segmentsat the other side of thecolled biplane filament M. This means that the grooves 25 and 25 are offset with respect to one another, when the blocks 18 and 59 are mated, corresponding with the desired offset or staggering between the segments M of the two rows of the filament ll, that is, a distance equal to half the distance between adjacent grooves.

The grooves 25 and 26 are of a length corresponding with the length of the segments i l of the coiled filament ll while the blocks i8. and it are sufficiently longer to carry the outwardly flaring grooves 2;! in the lower block and 23 in the upper block. Said grooves 23 and 25 are respectively seniifrustoconical in shape, flaring from a diameter approximating or slightly larger than that of the mandrels 2 to a considerably larger diameter, so as to conveniently funnel the separate mandrels directly to the interior of coil segments held in the nesting grooves 25 and 26, respectively.

The function of the nests is to position the coiled segments and hold them at the spacing desired. The tapered entrances provided by the flaring grooves Z! and 2B allow for positive guid ing of the several pointed mandrels 5.2 simultaneously into the centers of the respective coiled segments 14. Preferably weak springs 29 and 3t are associated with the blocks 18 and 9 to, upon release, cause them to separate to the position shown in Figure 7, and allow for the convenient removal of the jig ll with a segmented coil ll thereon, as shown in Figure 3. Figure 8, however, shows such a filament in place on the jig I! after the application of an outer spacer plate It.

From the foregoing, it willbe seen that wehave devised a fixture for externally temporarily holding the individual coiled segmentsin proper relationship and, at the same time, providing fun nelling guides for receiving the mandrels of a for internally holding such coils while heat treated to setting positions. In the present embodiment, when used for biplane filaments, each block i8 desirably has a spacing leg 32, or one block has two of such legs, so that even when the blocks are mated, as in the position of Figure there is a space 33 between the planes of the two rows of filament segments.

If, however, the device were used with a monoplane filament, there would be no such spacing and no necessity for such extensions 32, because all of the coiled segments would lie in one plane.

In all instances, however, weak springs indi cated at 29 and 3| would preferably be employed for moving the blocks to a release position, shown in Figure 2, said springs having their ends desirably set into pockets 34 and 35 for spring 29, and 3G and 3'1 for spring 31.

A preferred method of employing the fixture described is as follows:

1. The mandrels ii are threaded through two spacing blocks L6. to pre-position them..

2. A coiled filament H is pushed into. the nest end of the fixture, when held in the position of Figure 4, and positioned as there shown, the inner ends of said coiled segments is engaging the shoulders 38, formed at the junctions between the nesting grooves 25 and 26, on the onev hand, and the tapered entrance grooves 27 and 28'. on the other.

3,. The pro-positioned mandrels l2 are inserted simultaneously into thev tapered guiding. grooves.

until all of the coiledsegments M. are threaded thereon, as shown in Figurev 6.

l. The fixture 28 is then released, allowing the blocks 18 and it to separate to the position of Figure 7. The jig Il may then be removed with a coiled filament H in place thereon.

5. The threaded coil H isthen moved toward the other end of the jig I1, and a spacing bar H3 is placed in front of it, on the mandrels [2, as shown in Figure 8. This procedure is continued until the mandrels are filled to capacity, say up to. 1.6.01. 18 coiled filaments.

6. The coils, are then baked. while. in placeon the mandrels in a hydrogen furnace. atv about 165.0. C. for about 30 minutes, cooled, and removed. The coiled segments. will. be found. perfectly aligned, spaced, and ready for mountingv in bulbs to make lamps.

The employment of the. fixture heretofore described, and the practicing of. the method disclosed, results in the. following advantages.

1..The elimination of hand adjusting, which was, slow, tedious and costly.

2. With the loading fixture, the process OfSBi'nting coils by baking has. been madev practical and efiicient. At mounting, such coils require less adjusting, thereby speeding. up. production and giving greater uniformity.

3. The loading fixture permits the accuratereshaping of approximately 43.00 coils per week. per operator.

4. Coils which formerly would be classified. as shrinkage and unadjustabl'e by hand, can be nested and threaded with no trouble using the loading fixture of our invention.

5. Mechanical threadingis now deemed a possibility, using the above-mentioned loading, fixture asa basis.

6. The fixture has been used in factory work with a great deal of success, making it possible to meet high production. demands.

Although a preferred embodiment of our invention has been disclosed, it will be understood that modifications may be made.

We claim:

1. A fixture for holding the coiled lengths of a filament, when bent into a plurality of side-byside segments, staggered from one plane to a parallel spaced plane, with alternate segments lying in equally spaced planes parallel to one another, and perpendicular to said first-mentioned planes, in position for being threaded on the mandrels of a setting jig, comprising a pair of blocks movable between releasing and mating positions, which have generally semi-cylindrical depressions, respectively corresponding in spacing with that desired for the filament segments in said first-mentioned planes, extending parallel to one another from one end, terminating short of the other, spaced and numerically corresponding with the segments of such a coiled length of filament, the depressions in one block being, when the blocks are mated, offset along their plane, with respect to the depressions of the mating block, a distance equal to half the distance between adjacent depressions so that they will nest the opposite sides of segments of such a filament and hold said segments in properly spaced staggered parallel relationship, entrance depressions in said blocks extending from the inner ends of said nesting depressions, fiaring outwardly from a diameter only slightly larger than that of the mandrels and not greater than the inside diameter of the turns of said segments, forming guides for funnelling said mandrels into the respective segments of said filament, and means for guiding said blocks to and from mating position.

2. A'fixture for holding the coiled lengths of a filament, when bent into a plurality of side-byside segments, staggered from one plane to a parallel spaced plane, with alternate segments lying in equally spaced planes, parallel to one another, and perpendicular to said first-mentioned planes, in position for being threaded on the mandrels of a setting jig, comprising a pair of blocks movable between releasing and mating positions, which have generally semi-cylindricaling with that desired for the filament segments in I said first-mentioned planes, extending parallel to one another from one end, terminating short of the other, spaced and numerically corresponding with the segments of such a coiled length of filament, the depressions in one block being, when the blocks are mated, offset along their plane, with respect to the depressions of the mating block, a distance equal to half the distance between adjacent depressions so that they will nest the opposite sides of segments of such a filament and hold said segments in properly spaced staggered parallel relationship, entrance depressions in said blocks extending from the inner ends of said nesting depressions, flaring outwardly from a diameter only slightly larger than that of the mandrels and not greater than the inside diameter of the turns of said segments, forming guides for funnelling said mandrels into the respective segments of said filament, and a plurality of studs on one of said blocks fitting corresponding apertures in the other block for insuring that said blocks properly register with respect to one another and for subsequently guiding them between mating and releasing positions.

3. A fixture for holding the coiled lengths of a filament, when bent into a plurality of side-byside segments, staggered from one plane to a parallel spaced plane, with alternate segments lying in equally spaced planes parallel to one another, and perpendicular to said first-mentioned planes, in position for being threaded on the mandrels of a setting jig, comprising a pair of blocks movable between releasing and mating positions, which have spacing legs extending therebetween and depressions respectively corresponding in size and spacing with that desired for the filament segments in said first-mentioned planes, extending parallel to one another from one end, terminating short of the other, spaced and numerically corresponding with the segments of such a coiled length of filament, the depressions in one block being, when the blocks are mated, offset along their plane, with respect to the depressions of the mating block, a distance equal to half the distance between adjacent depressions so that they will nest the opposite sides of segments of such a filament and holding said segments in properly spaced staggered parallel relationship, entrance depressions in said blocks extending from the inner ends of said nesting depressions, flaring outwardly from a diameter only slightly larger than that of the mandrels and not greater than the inside diameter of the turns of said segments, forming guides for funnelling said mandrels into the respective segments of said filaments, springs disposed between said blocks and partially housed in said spacing legs for normally holding said blocks spaced from one another to allow for insertion and removal of such a filament, and means for guiding said blocks to and from mating position.

4. A fixture for holding coiled lengths of a filament, when bent into a plurality of side-byside segments, in position for being threaded on the mandrels of a setting jig, comprising a pair of blocks movable between releasing and mating positions, which have depressions respectively corresponding in spacing with that desired for the filament segments, extending parallel to one another from one end, terminating short of the other end of said blocks, spaced and numerically corresponding with the segments of such a coiled length of filament, so that when in mating position they will nest the opposite sides of segments of such a filament and hold said segments in properly spaced parallel relationship, entrance depressions in said blocks extending from said terminated-short ends of said nesting depressions, fiaring outwardly from a diameter only slightly larger than that of the mandrels and not greater than the inside diameter of the turns of said segments, forming guides for funnelling said mandrels into the respective segments of said filament, means for guiding said blocks to and from mating position, and means resiliently tending to separate said blocks to releasing position.

5. A fixture for holding coiled lengths of a filament, when bent into a plurality of side-byside segments, in position for being threaded on the mandrels of a setting jig, comprising a pair of blocks movable between releasing and mating positions, which have depressions respectively corresponding in spacing with that desired for the filament segments, extending parallel to one another, terminating at one end short of that end of said blocks, spaced and numerically corresponding with the segments of such a coiled length of filament, so that when in mating position they will nest the opposite sides of segments of such a filament and hold said segments in properly spaced parallel relationship, entrance depressions in said blocks extending from said terminated-short ends of said nesting depressions, flaring outwardly from a diameter only slightly larger than that of the mandrels and not References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Hotchkiss Aug. 2, 1861 Batchelder Dec. 31, 191-8 Hayden June 10, 1919 Fehse Aug. 27, 1929 Number N umber Name Date Zabel Feb. 26, 1935 Sefcik, Jzt. Mar. 9, 1937 Lee May 18, 1937 Parker Dec. 24, 1940 Shafier Oct. 29, 1942 Young Oct. 29, 1946 Isaac et a1 Sept. 21, 1943 Brunner et a1 Jan. 2, 1951 Beltz June 5, 1951 FOREIGN PATENTS Country Date Great Britain July 4, 1947

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