US1817783A - Method and apparatus for inside coating bulbs - Google Patents

Description

Aug. 4, 1931. K. TSUYUKI IMETHOD AND APPARATUS FOR LNSIDE COATING BULBS Filed Sept. 30, 1927 I'nve-ntor": I Kei ji Tsuguki,

bg flbwc His Atbov neg.

" 15 efiect o Patented na 4.1931 1 I 1,817,783

UNITED STATES PATENT- oFF-lca 1in 'rsmm. or mono, urm. assronoa ro GmmB-LL morale team, a

- conronanou or new YORK mnonm arranarus ron. rusrnn coa'rr 'to some.

Application inea September so, 1927, Serial n. 223,147, and in as... 0mm so, 1920.

The present invention relates to a method facturing lamps which are half frosted or a of and ap aratus for applying to apart of the bowl frosted onthe outside b an etchin inner sur ace'of a lamp bulb or similar glass compound isimpossible; to picli up the bulb containerhaving only one neck or opening carefully and inside frost the bowl of the bulb 5 a protective coating prior to frosting theunby gfntly pouring the etching compound into 55 coated part of the inner surface by etchin the ulb while held bowl down is troublesome and more particularl to coating a selects and requires skill; and sand blasting the ingfi'll' of the inner sur ace of the bulb with a side of the bowl of the bulb is attended by of protective material, preferablyby many difliculties and troubles if done on a dipping it neck downward into said material commercial scale. By the presentinvention, c in liquid form, and venting the air in the however, the bowl art of the inside of the bulb to the atmosphere so as to cover the bulb can be frosted y'practically any frostsubmerged portion of the bulb with a film lng process, because a protective film not afwhich tprotects the glass surface from. the fected by the etching or frosting compound is,

etching compound. by a simple and easy operation which requires as The object of the invention is to provide no skill, ap lied to the part which is not to be simple and reliable means for coating a bulb frosted. T e invention can be practiced by or similar article on only a part of the. inside hand, but I prefer to coat that portion of the surface, and to accurately limit in a simple inside of the bulb which is to'remain clear way not requirin an particular skill the with a film of a protective material resistant m area afiected by the etc g compound. to the etching compound by means of a malhe invention relates more particularly to chine which handles the bulbs to form a'film amethod of confinin the frosting to a preof a protective material, such as parafiin, on determined art of t e inside surface of a a desired portion of the inside of the bulb, bulb or sim'v a1 empty glass container havand fixes the film on the glass by cooling it. 16 ing one neck or opening, by placing the bulb lhen the uncoated portion of the inside of with the opening downward, venting the inthe bulb is frosted, usually by a machine. terior of the bulb by connecting it to the at- The invention will best be understood in mosphere, as for example,by means of a conconnection with the accompanyin drawings, necting (tube, and dipping the bulb into the in which one embodiment of the invention is so liquid protective material to such a depth illustrated and in which Fi e l is a view that the only part which remains free from in perspective with parts bro en away of one a film or coating of the protective material is form of apparatus for applying the protecthat p artof the inside surface which is to tive film priorto frosting, and Figure2 shows be frosted y the etchin compound, which the coated bulb produced on the-machine, s5-

usually contains hydrouoric acid. A sat- The particular machine shown comprises isfactory material for protecting the glass a table 1 on which several heads construe d from the etching c0mpound,'and one that to hold the bulbs aremounted to recipr has a low melting point and easily coats the vertically and also travel step by-step along glass surface, is parafiin or wax. a circular path. -Each head or bulb holder 90 It has heretofore been considered diflicult comprises bulb clamps 5 and 6 secured to the to frost only a part of the inside surface of lower part 'of'a vertical rod 4 suspended from a bulb having only one neck or opening and an arm of a spider fixed to the upper part w articularly to manufacture by the inside of a reciprocating and rotatablerarrier for rost method the so-called half frosted or the heads, such as a shaft 2 WhlCh extends 9 bowl frosted lamp and keep the half near the vertically through the table 1. Each head neck transparent and frost the other half holds the bulb with its neck downward and toward the bowl or top, although there is 8. its longitudinal ans vertica To the lower lar 'e demand for such lamps. To use the part of the carneror shaft 29. drwmg mechordmary method and apparatus for manuanisrn is attached in order to reciprocate and 1 0 highest position, where it is rotated one step to move the head or bulb support from one working position to the next, and since, in the apparatus shown in the drawings, there 5 are four heads the shaft makes one revolution in four steps, so that the shaft 2 turns one fourth of a revolution each time it rotates. The driving mechanism for rotating the shaft intermittently is preferably a Geneva gear comprising a notched wheel 9 with a film that protects the glass surface d splined on the shaft 2 to rotate it regardless of the reciprocating movement of the said shaft and making one fourth of a revolutlon for each revolution of the driving pinion 10- which has a pin 11 to engage the notches on the wheel 9. The relative speeds of the countershaft 12 for the cam 8 and the driving shaft 13 of the pinion 10' are such that when the shaft 2 is in its highest position the Geneva gear rotates it one fourth of a revolution. Each head or bulb support is lifted by the cam 8 at each working position and while lifted it is rotated one fourth of a revolution by the Geneva gear to the next working position where it is lowered and this operation is repeated to carry each head from one working position to another.

The coatmg device by which any desired part of the bu b supported in a head is coated from. the effect of the etching compound, is placed at one of the points where the head or bulb supports stop as the shaft 2 intermittently rotates on the table 1. The particular device shown comprises a tank 14 for a static or quiet body or pool of paraflin or wax,

' which is resistant to an etching compound containing hydro-fluoric acid, and in the tank is a heating coil, suchas a steam pipe. 15 which extends outside the tank. The is melted and rendered liquid by heating it. To rmit the li uid paraflin to rise inside the b ulb to the evel of the uiet body of melted paraflin in the tankthe ulb is vented through the neck by some means, such as a vent pipe 16 which stands vertically in the tank and opens through the bottom of the tank and is so mounted-that it is inali ent with the axis of the bulb held by the bulb into the static body of melted paraflin as the bulb is lowered with the, bulb su port, the vent ipe assists the bulb to sink into the para by exhausting or venting the air in the bulb to the outside.

7 ens the paraflin film on paraflin be fr 0 support, so that as the neck of thebulb sinks A filmfixing device, which sets and hard the glass surface may be placed on the table 1 in one of the working positions reached by the head 'durin travel. The ap aratus shown in the ings facilitates h rawardening of the coating by itsso locating the fixing device that each head stops between the coating device and the fixing device (position 0) to permit the excess parafiin to drain oil and the coating to cool to some extent. However, it is not always necessary to do so. The film .fixing device comprises an open ended vessel or tank 18 havin an outlet pipe 17 at the bottom, and a for ed inlet pi 19 with a pluralit of orifices or sprink ers so placed that a ulb,

lowered into the tank by the head in which it'is supported, is surrounded by said water pipe 19 whereby the araflin coat on the glass is sufliciently cooled y water sprinkled on it, thereby fixing the coating.

The next stop of the head is at .the loading and delivery position A where the operator who stands at this position A removes the coated. bulb and inserts an uncoated transparent bulb into the bulbclamps 5 and 6 while the head is stationar The shaft 2 lifts the bulb and the head because of the rotation of the shafts 12 and 13, transfers it to the coating position B, and then lowers it into the quiet pool of melted paraflin in the tank 14. The extent of dipping the bulb into the araflin is varied as desired by adjusting t e point of attachment of the rod 4 to the arm 3 in accordance with the height of surface of the paraflin and the extent of the portion of the bulb to be coated with protective film. The bulb is lowered and is pool of parafiin as dipped into'the guiet eep as the boun a l ne of the area desired to be coated. T en, since the air sealed in the bulbas the neck enters theparaflin can escagelfreely throu h the vent pipe 16 the para surface inside the bulb equalizes with that on the outside so that the inside surface of the bulb except the part where frosting is desired is completely wetby the paraflin and-when lifted up by the-head all inner surface of the bulb, except the part to osted, is coated with paraflin. According to the kind of paraflin, and the temperature of the location of the apparatus the been coated with paraflin at B is transferred step by step to the position D and there goes down into the fixing tank 18 with the result that the Paraflin is cooled and sticks to the glass sur ace because of the shower of water sprinkled upon it from pipe 19.

I 1,a17,ve'e

When the bulb comes back to position A the operator takes the bulb which is coated with parafin out of the support and replaces it with an uncoated bulb. I

The bulb that has been coated with the protective film of araflin on a part of the inside surface may frostedby any known method and apparatus, and then the protective film or coat on the glass surface is taken ofi preferably by blowing into the bulb an alkaline steam.

What is shown in the drawings is an apparatus for facilitating the carrying out of the preparation of the bulb, but if the position for blowing'the alkaline steam into the frosted bulbs be placed in proper relation to the working positions of the inside frosting machine for incandescent electric lamps orsimilar articles the troubles due totransfer of the coated and frosted bulbs to different machines are greatly lessened.

The bulb 20 after it has been coated by the machine as above described has, as best shown in Figure 2, a thin protective coating of parafin 21 on the inside which leaves only the bowl of the bulb exposed to the etching compound.

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

1. The method of temporarily coating a portion of the inside surface of a hollow glass article having one opening which consists in submerging the opening of the article to a pre-determined depth in a static 'pool of molten liquid coating material, venting the article through said opening to permit the molten material to rlsein said article and thereby wet a pre-determined portion of its inner surface, cooling said article to convert the adherent material on the wetted surface into a solid protective coating and subsequently removing said coating.

2. The method of temporari y coating :1. portion of the inside surface of a hollow glass article having one opening which consists in submerging the o ning ofthe article to a predetermined dept in liquid paraflin,

venting the article through said opening to protecto reciprocate vertically, an open ended 'coating vessel mounted on said table with its open end adjacent the path of said holder, a vertical vent pipe inside said vessel in alignment with the axis along which said bulb holder reciprocates, an open ended fixing vessel on said table with its open end adjacent the path of said holder,-and actuating means for intermittently rotating said holder to bring it into registry with said vessels in succession, and to lower said holder while in registry with said coating vessel to dip the neck of a bulbinto said vessel and over said vent pipe and then raise said holder, and to lower the bulb into and raise it out of said fixing vessel while said holder is in: registry with said fixing vessel.

. In witness whereof, I have hereunto set my hand this 6th day of September, 1927.

' KEIJI TSUYUKI.

permit the parafiin to rise inside said article to the same level as outside, and thereby wet a predetermined portion of said inner surface, cooling the coated article to convert the adherent liquid paraflin on the wetted surface into a solid protective coating, and subsequently removing said solid coating by treatment with an alkaline reagent.

3.- The method of temporarily coating 2. portion of the inside surface of a hollow glass article having one opening which consists in submer 'ng the opening of the article to a predetermined depth in a bath of heated pra, venting the article through said opening to permit heated paratfin to rise in said article to the outside level of the bath and thereby wet a predetermined por-

Images