US1915361A - Method of sealing-in - Google Patents

Description

June 27, 1933. D. s. GUSTIN umxon or SEALING-IN Filed Dec. 2s, 1929 2 Sheets-Sheet 1 INVENTOR V Arman June 27, 1933..

i D S. GUSTIN METHOD OF SEALING-IN File d Dec. 28. 1929 2 Sheds-Sheet 2 INVETOR l5 ATTORNE I Patented June 27, 1933 UNITED STATES PATENT OFFICE S. GUS'I'IN, OI BLOOMZFIELD, NEW JERSEY, ASSIGNOR '10 WESTINGHOUSE LAID COMPANY, A. CORPORATION OF PENNSYLVANIA METHOD SEALING-IN Application med December 28, 1929. Serial No. 417,108.

' This invention relates to the manufacture of electrical devices such as incandescent electric lamps in which a base is secured to a lamp bulb by a mechanical connection between the base and the bulb neck as shown and described'in my copending application Serial No. 229,825 filed October 31, 1927 and relates more particularly to a method of shaping a bulb neck to receive a retainer ele- 1T6 ment for securing the bulb andbase in fixed relation. I

In the manufacture of electrical devices such for example, as incandescent electric lamps it is the practice to provide the lam 1-5 with a base in the formbf a threaded she I or cap having one end open to receive the end or neck portion of a glass bulb. Bases ofthe above. character have usually been secured to the bulb by means of a quantity of cement 2 which is deposited in the base after which the bulb and base are disposed in the desired relation d the cement is subjected to a baking opera ion to set the cement and firmly secure, the bulb and base in fixed relation.

The above construction has been extensively used but certain disadvantages attend this mode of manufacture since it is time con suming and relatively expensive and involves a heat treating operation.

In my copending application above mentioned I have provided a structure which eliminates the use of cement but at the same time utilizes the standard type of screw shell or base. .-The' structure set forthin the said application includes a split or otherwise resilient collar having a circular outside per- 'imeter and having its central or internal perimeter of non-circular form. The said collar snugly fits the interior surface of the base or shell and the non-circular perimeter grips the bulb neck.

'It will be appreciated, however, 'that in order'to' obtain the proper gripping action- '-between the non-circular perimeter of the collar and the bulb neck, that the said neck must be formed to a-predetermined shape to .conform with the formation of the internal erimeter of the collar so that when the base 0 is applied over the collar the latter will be firmly pressed into contact with the accommodating formation in the bulb neck.

When the collar and base have been disposed in proper relation the said base and collar are secured together by solder or by a brazing operation. One of the lead'wires of the lamp may be disposed between the tained by forming the depressions in the bulb neck by ordinary methods, better re-' sults and-greater strength is obtained by performing the bulb shaping operation in accordance with the present method to be hereinafter described.

It is an object of the present invention, therefore, toprovide a method of quickly and effectively shaping a bulb neck to receive a retainer member.

Another object of the invention is to rovide a method for shaping a bulb nec to receive a retainer member and in attaining a maximum strength at the shaped portion.

Another object of the invention is to provide a method of shapinga bulb neck wherein the material of the shaped portion is of greater thickness than before the shaping operation'. 7

Other objects and advantages of the invention will be more fully understood from the following'description together with the accompanying drawings, in \which Fig; 1 is a side elevational view of a holder or head for supporting a lamp mount and a bulb in position for consolidation therewith.

Fig. 2 is a. fragmentary view of a head showing a bulb and mount in position with fires for contracting the bulb neck about the flare tube of a mount.

Fig. .3 is a view similar to Fig. 2 but shows the position of softening fires for causing a thickening of the bulb wall above its union with the flare tube, also fires for severing the cullet.

Fig. 4 is a cross sectional view of a portion of the bulb neck showing the thickened glass after the neck has been shaped.

Fig. 5 is a perspective view of a: holder showing jaws for compressing the softened bulb neck to form the same to a predetermined shape. I

Fig. 6 is a fragmentary detail cross sectional view showing one of the jaws in contact with the softened glass.

Fig. 7 is a side elevational view of; a bulb partly broken away and showing the'formed neck portion.

Fig; 8 is a view taken on line VIIIVIII in Fig. 7 Fig. 9 is a side elevational view of a bulb partly in section showing an annealing fire also a cut off fire for severing the cullet and shows the severed culletin dotted lines.

Fig. 10 is a view of-a bulb partly in section with the cullet removed and an annealin fire indicated in dotted lines.

Fig. 11 is aperspective view of a retainer ring or resilient, collar employed as a retainer member to secure the base to the bulb neck, and

Fig. 12 is a fragmentary cross sectional view showings. bulb neck and base secured together by aretainer member.

In practicing the present method a bulb 10 is employed having a neck portion 11 and a cullet '12 which may be supported in a holder 13 ready for movement over a mount 14, the said mount may comprise a flare tube 15 secured to an arbor 16 at a press 17 111 the usual manner. The arbor may be provided with support wires 18 for supportln a filament 19. An exhaust tube 21 may e provided in communication with an outlet 22 for exhausting purposes when the mount has been sealed'to a bulb. The flare tube 15 is provided .with a flange 23 and'in the present method it is desirable to have an appreciable portion of the said flange disposed in a lane transverse to the longitudinal axis of e mount as distinguished from flare tubes as heretofore constructed in which the flange instead of being of a substantial right angle construction, sloped downwardly toward its perimeter.

.The mount may be disposed in a head 24 by securing the exhaust tube 21 in the usual holder or chuck provided in heads for performing what is termed a sealing-in operation, which in lamp making comprises the fusing of the flange of a flare tube to a bulb neck. The bulb 10 may be moved to position as shown in dotted lines in Fig. 1 so that it rests upon contact surfaces 25 extending inwardly'toward the axial line of the head which provides a seat upon which to rest the bulb. Centering jaws or members 26 may be provided to engage the bulb neck and hold the same in concentric relation with respect to the flare tube 15. A head holding a bulb and mount in the manner above described may be rotated by suitable mechanism, (not shown), and sharp pointed sealing fires27 may be directed against the outer surface of the bulb neck adjacent to the perimeter of the flange 23. This operation contracts the bulb neck and fuses it with the said flange shown in Fig. 2.

After the neck has been consolidated or united with the flare tube, shaping'or softening fires 28 (see Fig. 3) are directed against the bulb neck above the point of consolidation between the bulb and flare. These fires serve to soften an appreciable portion of the glass above the flare and to contract the same at which time the glass accumulates resulting in a thickened portion 29 (see Fig. 4) While the glass is still molten a plurality of shaping jaws 31, 32 and 33 are moved inwardly to shape the bulb neck to triangular form to receive a retainer member or collar 34 as shown in Fig. 11. This collar is in the form of a split ring having an outside cylindrical surface 35 and an interior perimeter comprising three straight surfaces or edges 36, 37 and 38.

The jaws 31, 32 and 33 are of substantially the same shape as one of the straight edges of the collar 35 so that when the jaws have pressed the neck of the bulb to the proper depth the straight edges 36, 37 and 38 of the retainer member will be accommodated by the depressions formed and the said edges will seat in the depressions so that the retainer member will snugly fit the shaped portion of the bulb neck and be ready to receive a base 39 which fits the collar 35 and may be secured thereto by either a riveting ora soldering operation.-

During the operation of shaping the bulb neck by means of the jaws 31, 32 and 33 air under pressure may be directed through passage 30 which communicates with the exhaust tube 21 so that the softened glass is forced firmly against the shaping jaws. After the forming jaws 31, 32 and 33 have pressed and shaped the bulb neck, the cullet 12 may, as shown in Fig. 9, be removed by directing a cut off fire 41 against the cullet at a point below the union between the flare tube and bulb neck at which time air is admitted to the space 41 to aidin breaking away or severing of the glass softened by the cut off fire 41.

An annealing fire 42 may also be emplo ed.

nausea down is accomplished by a downward moveis necessarydo .is ready ment of the chuck which secures the exhaust tube. The plastic material at-the seal is thus worked and internal stresses are removed, means for causing the pull-down are not shown since this feature is well known in the lamp art in connection with the sealing-in operation.

As shown in Fig. a bulb having the neck shaped to receive a retainer member is positioned in an exhaust port 44 of an exhaust machine. When in this position it has been found desirable to direct an annealing fire 45 against the union between the bulb neck and flare tube to remove-any internal stresses and revent subsequent cracks or breaks. When in the exhaust machine the bulb is exhausted and tipped oil in the usual manner. When removed from the exhaust machine the bulb to receive abase and a retainer member, may thenbe slipped over the shaped por-. tion of the bulb neck and a base disposed over the retainer, member and secured thereto as shownin Fig. 12.

It will be understood that "when providing a lamp with a mechanically attached base it obtain the greatest amount of strength in the bulb neck since by reason of the mechanical connection a certain amount of stressjis applied to the bulb neck during handling or use of the lamp when in operation.

By reason ofthe present invention, therefore, a method is provided in which the bulb neck may not only be shaped but strengthened to such an extent that it provides a rugged structure to meet practical requireradical departure "mechanical basing of lamps practical.

.ment, formatlon anddirection of the is accomplished primarily by the arrangeworking fires. Heretofore various'types of mechanical bases were produced but owing to the fragile condition of the bulb neck, such structures as had been produced were too delicate for the handling attending lamp manufacture and the use of lamps so that a lamp mechanically based by ordinary methods would break at the shaped portion or rupture in the event that an was applied as for examp e was screwed into a socket. The resent invention '"provides a reinforced s aped bulb neck of sufiicient strength to resist breakage and has therefore made the when a" lamp Although a preferredaembodim'ent of invention is shown and described herein it is to understood that modifications may;

glass excessive force made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. The method of sealing-in and shaping a bulb neck which comprises sup orting a bulb with the neck portion thereo disposed about the flared portion of a mount, fusing the neck to said flared portion to reform the material in said neck to provide a greater thickness of wall adjacent to the flared portion and in shaping said thickened portion.

2. The method of sealing-in and shaping a bulb neck which comprises supporting a bulb with the neck portion thereof disposed about the fiared portion of a mount, fusing the neck to said flared portion to reform the material in said neck to provide a greater thickness ofwall adjacent tothe flared portion, admitting fluid under pressure into the bulb neck and in compressing the said thickened portion to a predetermined form.

3. The method of forming a bulb neck to receive a base retainer member which comprises supporting a bulb and mount with the flange of the mount disposed within the bulb neck, heating the bulb neck to cause the wall thereof to contact with the flange, heating the bulbneck above the flange to reduce the diameter thereof and thicken the wall and in forming the thickened wall to receive a retainer member.

4. The method of forming a bulb neck to receive a base retainer member which com prises supportinga bulb and mount with the flange of the mount disposed withi the bulb neck, heating the bulb neck to cause e wall thereof to contact with the flange, heating the bulb neck above the flange to reduce the diameter thereof and thicken the wall thereof and in forming the thickened wall to a predetermined shape in transverse cross section.

5. The methpd of forming a. bulb neck to receive a base retainer'member which comange, disposing a lamp bulb having a cullet over said mount with the bulb neck surrounding the flange",

heating to contract and fuse the bulb neck about the flange, rendering plastic a portion of the bulb neck above the flare to contract the same and to reform the material m said portion to provide a greater thickness of wall shaping the thickened portion and severing the cullet.

6. The method of forming a bulb neck to receive a base retainermemberwhichwom;

prises supporting 'a'lamp glass flange, positioning mount with said flange adiacent to the'in terior. wall of the bulb neck, heating the bulb neck? a ut said flange to. .contract the same *an flmite .th wall" 0f saidfneck With the perimeter of said flange, heating said bulb, neck above thesaid union-tocause the wall" /mount having a t a bulb about the to decrease in diameter and increase in thickness, and in admitting air under pressure into saitlil bulb while shaping the sand thickened wa In testimony whereof, I have hereunto subscribed my name this 20 day of December v DANIEL S. GUS'lI-N.

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