US2788157A - Fluid dispensing device - Google Patents

Description

P 1957 K. w. REYNOLDS ETAL 2,788,157

mun mspsnsmc DEVICE Original Filed July 16, 1952 Invervtovs: Kennedih W Regnotds,

' John ABILLson, CLi=f""I"oT"ci E. RauSch,

FLUID DISPENSING DEVICE Kenneth W. Reynolds, Mayfield Heights, John A. Billson, Warrensville Heights, and Clifford E. Rausch, Warren, @hio, assignors to General Electric Company, a corporation of New York Original application July 16, 1952, Serial No. 299,286, now Patent No. 2,732,847, dated January 31, 1956. Divided and this application October 19, 1954, Serial No. 463,132 1 v 2 Claims. (Cl. 222-69) Our invention relates to a fluid dispensing device for discharging a predetermined quantity of a fluid. This application is a division of our co-pending application Serial No. 299,286, filed July 16, 1952, now Patent No. 2,732,847 of I an. 31, 1956, and assigned to the assignee of the present invention.

In the production of glass lamp bulbs having a metallic reflecting coating on certain selected areas of their inner walls, the common practice is to first coat substantially the entire inner surface of the bulb either by depositing metallic silver or other like metallic reflective coating material from a solution, or by thermally vaporizing the coating metal onto the bulb wall while the latter is in a partially evacuated condition. Subsequently, the metallic coating is removed from that area of the bulb inner wall which is to be left clear. Thus, in the production of a metallic reflector coated bulb intended for direct lighting purposes, the metallic coating is removed from the rounded or bowl end portion of the bulb up to substantially the line of maximum diameter thereof. In this operation it is highly desirable that the metallic coating have a sharp, clean cut-ofl? line, and further that this cut-off line be accurately and uniformly located in the bulbs in accordance with the optical effect which is desired.

The procedure most generally employed at present for removing the metallic coating from the bowl end of an interiorly coated lamp bulb consists in chemically dissolving the metallic coating off such bulb wall portion by carefully filling the coated bulb, while held in an upright neck-up position, to the desired cut-off level with a suitable solvent or acid dissolving solution introduced through a tube inserted in the bulb and, after permitting the solvent or acid to remain in the bulb for the required length of time to dissolve the metal of the coating up to the desired cut-off line, then withdrawing or removing the dissolving solution from the bulb through the said tube. In order to obtain accurate and uniformly located reflector coating cut-off lines in the finished bulbs with such a process, it is necessary to supply measured changes of the dissolving solution to the coated bulbs and to predetermine the volume of such charges in exact accordance with the level to which the coating is to be removed. 7

It is an object of our invention, therefore, to provide dispensing apparatus of simple character and positive in operation for dispensing predetermined quanties of liquid therefrom.

Further objects and advantages of our invention will appear from the following detailed description of a species thereof and from the accompanying drawings.

In the drawings, Fig. 1 is a diagrammatic illustration of a liquid dispensing apparatus comprising our invention, and

Fig. 2 is a vertical section of the liquid charge-measuring device of the said apparatus.

nited States Patent C ice The dispensing apparatus of our invention is herein described and illustrated for use in removing reflector coatings of metallic silver or other like metallic reflective material from the inner side of the bowl end portion of lamp bulbs which have been previously provided with such internal reflector coatings over substantially their entire interior surface. The dispensing apparatus is adapted to accurately and successively measure and dispense into the bulbs to be treated and subsequently withdraw therefrom individual charges of a liquid medium such as acid dissolving solution for dissolving the metallic reflector coating off the bulb end face. For a fuller understanding of this particular application of the measuring and dispensing apparatus of our invention, reference may be had to the above-mentioned co-pending application Serial No. 299,286.

Referring to the drawings, the measuring and dispensing apparatus according to the invention comprises, in general, a charge measuring device or flask 1 which is alternately filled to a predetermined level with liquid from a supply tank or reservoir 2, and then emptied to a predetermined level by discharge of the liquid therein into a filling head 35 inserted in the bulb 4 to be treated. The charge measuring device 1 is mounted at an elevation substantially corresponding to that of the tank 2 and above the filling head 3, and it comprises a vertically arranged tube or flask 5, preferably made of glass, provided with an outlet connection 6 at its lower end and a side inlet connection 7 located more or less midway between the upper and lower ends of the tube at a level slightly below the corresponding tank outlet 3 to which it is connected by a length of flexible chemically-resistant tubing 9. The upper end of the tube or flask 5 is closed off by a rubber plug or stopper 10 having a central bore 11 in which a metal tube or bushing 12 is snugly received so as to have an air-tight fit therein. The bushing 12 projects outwardly above the top of the stopper 10 and is provided with an enlarged head or collar portion 13 which rests on the top of the stopper 10. The inner and outer walls of the collar portion 13 converge upwardly to a sharp edge to form a circular knife-edged seat 14 at the top of the collar.

Disposed within the tube or flask 5 is a float 15, preferably made of glass and consisting of a lower bulb portion 16 having a vertical stem portion 17 extending loosely through the passageway or bore 18 in the bushing 12 and projecting upwardly therebeyond. The stem 17 of the float 15 is provided, internally of the flask 5, with an enlargement or stop collar 19 which is adapted to abut against the lower end of the bushing 12, as the float rises during the filling of the flask 5 with acid solvent from the tank 2, to thereby limit the upward movement of the float and thus avoid any tendency of the float to become wedged or to bind in a tilted position, when elevated, such as would prevent it from moving freely downward in the flask 5 when the fluid is subsequently withdrawn therefrom. The limiting of the upward movement of the float 15 by the stop collar 19 thereon also serves to prevent excessive protrusion of the fragile glass stem 17 outwardly of the flask such as would render it subject to accidental breakage. To avoid the possibility of the stop collar 19 closing or sealing 01f the passageway 18 in the bushing 12 (during the filling of the flask 5 with acid solvent from the tank 2) such as would result in the building up of a back pressure of air in the upper region of the flask above the level of the acid solvent therein, which pressure would therefore interfere with the flaskfilling operation and would prevent the filling of the flask with the proper amount of acid solvent, the lower rim end of the bushing 12 may be formed with one or more recesses in the form of serrations or notches 20 to provide passageways which communicate with the bore 18 of the bushing, when the float stop collar 19 is abutted against the lower end of the bushing, so as to permit the flask 5 to breathe? at such time through the bushing passageway- 18.

Snugly fitted on the projecting upper end portion of the float stem 17, so as to have an air-tight fit therearound, is a rubber collar or valve head 21 which is adapted to move down onto and seat against the circular knife-edged valve seat 14 of the bushing 12, during the flow of acid solvent out of the flask 5 into the respective filling head 3, to hermetically close off the passageway 18 through the bushing and thus stop the outward flow of acid solvent from the flask into the filling head, by reason of the partial vacuum. created in the upper portion of the flask by the continued slight lowering of the acid solvent therein immediately following the seal-off of the flask by the collar or valve head 21. The collar or valve head 21 thus acts as an atmospheric pressure valve to accurately control the amount of acid solvent flowing out of the flask 5 into the fillinghead 3. The rubber collar or valve head 21 is slidable on the float stem 17 so as to be vertically adjustable thereon in order to alford precise control over the amount of acid solvent which is allowed to flow out of the flask 5 and introduced into the bulb 4.

The bottom outlet connection 6 of the flask 5 is connected by a length of flexible chemically-resistant tubing 22 to the inlet tube 23 of the filling head 3. The outlet tube 24 of the filling head 3 is likewise connected by a length of flexible chemically-resistant tubing 25 to the upper region of the tank or reservoir 2. The flexible connection tubes 9, 22 and 25 are provided with suitable shut-off valves 26, 27 and 28, respectively, which may be in the form of pinch clamps, for the purpose of controlling the flow of liquid through the said tubes.

In operation, with valve 27 closed, the valves 28 and 26 are opened to first fill the flask 5 with liquid from the tank, by gravity flow thereof from the tank through the connecting tube 9 and into the flask 5, up to a predetermined level as determined by the establishment of a predetermined level of the liquid in the tank as described in our aforesaid copending application Serial No. 299,286. During this flask-filling operation, the air in the flask above the rising column of liquid therein escapes out the clearance space between the stem portion 17 of the float and the wall of the bore 18 in the bushing 12. When the levels of the acid solvent or liquid in the flask 5 and in the tank 2 become equalized, thereby filling the flask up to the aforementioned predetermined level, the flask 5 then contains a measured charge of acid solvent for the bulb 4.

The valves 26 and 28 in the outlet tube 9 and return tube of the tank are now closed and the valve 27 in the outlet tube for the flask 5 is opened at the same time, thereby allowing the acid solvent in the flask to flow out the bottom outlet 6 thereof and through the tube 22 to the filling head 3 and into the bulb 4. At the instant the valve 27 is opened, a continuous column of acid solvent remaining from the preceding dissolving cycle is present in the tube 22 and extends from the flask 5 through the connecting tube 22 and down to the lower end of the inlet tube 23 of the filling head 3, the said liquid column having been retained within the tube 22 by the vacuum created in the upper portion of the flask 5, above the level of the acid solvent remaining therein, by the closure of the atmospheric pressure valve 21 during the previous dissolving cycle. However, since at the time the valve 27 is opened the column-retaining vacuum in the flask 5 is no longer present therein due to the open condition of the atmospheric pressure valve 21 at the top of the flask, atmospheric pressure therefore exists on both ends of the continuous liquid column in the tube 22. As a result, a siphoning action is initiated on the liquid column due to the lower elevation of the filling head 3 relative to the flask 5, the siphoning action thus causing the acid solvent to flow through the tube 22 from the flask 5 to the filling head 3 and into the associated bulb 4. The flow of acid solvent to the filling head 3 then continues until the atmospheric pressure valve 21 of the flask 5 is closed once again by the reseating of the valve collar 21 against the valve seat 14 which is brought about by the lowering of the float 15 in the flask. The closing of the atmospheric pressure valve 21 stops the flow of acid solvent out of the flask 5 through the action of the vacuum which is created in the upper part of the flask by the continued slight additional outflow of acid solvent therefrom which takes place immediately following the closure of the valve 21. The partial vacuum thus created in the top region of the flask 5 then holds the continuous column of acid solvent in theconnecting tube 22, extending from the flask 5 into the filling head 3. A predetermined amount or charge of acid solvent is thus measured and dispensed by the device 1 and is introduced into the bulb 4 by the fillinghead 3, the amount of the acid solvent charge being so regulated by the elevational setting of the valve 21 on the float stem 17 as to submerge the portion of the internal reflecting coating on the bulb which is to be removed, i. e. fill the bulb 4 up to the desired reflector cut-oif level thereof, which, for example, may be at the maximum diameter of the bulb as shown at 29 in Fig. 1.

Following a predetermined time interval suflicient to permit the acid solvent in the bulb 4 to thoroughly dissolve the internal reflector coating oft the submerged portion of the bulb wall, the acid solvent in the bulb is removed therefrom and returned to the tank 2 through the return tube 25. For this purpose, the valve 7 is closed and valves 28 and 26. opened, whereupon low pressure air is introduced into the bulb 4, while the latter is closed off to the atmosphere at its neck end, to thereby force the solvent out of the bulb back up through the filling head 3 and return tube 25 and back into the reservoir or tank 2. The compressed air is supplied to the interior of the bulb 4 by the opening of a valve 30 in a compressed air line 31 which passes through the filling head 3 and opens into the interior of the bulb. The sealing ofi of the bulb at its neck end, during the pressure blow-out of the solvent from the bulb 4, is efiected by the expansion or inflation of a rubber sleeve 32 on the filling head into engagement with the neck portion 33 of the bulb, the expansion or inflation of the rubber sleeve 32being effected by the introduction of compressed air thereinto through a compressed air line 34 passing through the filling head 3 and opening into the rubber sleeve 32.

Since the tank-outlet valve 26 is also open during the pressure blow-out of the acid solvent from the bulb 4, the acid solvent in the tank 2 therefore flows out of the tank and into the charge measuring flask 5 concurrently with the return of the acid solvent from the bulb into the tank. The subsequent re-establishment of the acid solvent in the tank 2 at the aforementioned predetermined level therein as described previously, while the tank outlet valve remains in its open position, then causes the flask 5 to fill with acid solvent from the tank up to the said predetermined level. The flask 5 thereby again contains a measured charge of acid solvent for the next bulb 4 to be treated.

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

1. A device for measuring and dispensing a predetermined quantity of a liquid substance comprising a vertically arranged tubular flask having a discharge outlet adjacent its lower end and an opening at its upper end, a closure plug fitted in said opening and closing it off, said plug having a vertical passageway therethrough, a float in said flask having, a vertically extending stem portion projecting upwardly through said passageway and having a loose sliding fit therein, a seal-off valve collar mounted on the outwardly projecting upper end portion of said float stem for adjustment along said stern, and means defining a valve seat on the upper side of the closure plug around the said passageway therein and engageable by said valve collar to close the said passageway and hermetically close off the upper end of said flask member.

2. A device for measuring and dispensing a predetermined quantity of a liquid substance comprising a vertically arranged tubular flask having a discharge outlet adjacent its lower end and an opening at its upper end, a closure plug of yieldable material fitted in said opening and closing it otf, said plug having a metal bushing providing a vertical passageway through the plug, the lower end face of said bushing having a recess therein, a float in said flask having a vertically extending stem portion projecting upwardly through said passageway and having a loose sliding fit therein, a stop collar on said float stern interiorly of said flask and of smaller diameter than said bushing and engageable with the lower end face thereof to limit upward movement of the float within the said flask, a seal-off valve collar mounted on the outwardly projecting upper end portion of said float stem for adjustment along said stem, and means defining a valve seat at the upper end of said bushing around the said passageway therein to close the said passageway and hermetically close ofl the upper end of said flask member.

References Cited in the file of this patent UNITED STATES PATENTS 1,013,448 Rose Jan. 2, 1912 1,366,862 Berry Jan. 25, 1921 1,711,782 Hamaker May 7, 1929 2,563,930 Hamann et al Aug. 14, 1951 2,588,057 Thomas Mar. 4. 1952

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