US3713461A

US3713461A - Seal rotary distribution valve

Info

Publication number: US3713461A
Application number: US00127189A
Authority: US
Inventors: V Notelteirs
Original assignee: US Philips Corp
Current assignee: US Philips Corp
Priority date: 1970-04-08
Filing date: 1971-03-23
Publication date: 1973-01-30
Anticipated expiration: 1990-01-30
Also published as: NL7005063A; DE2112905B2; JPS4683U; FR2089331A5; DE2112905A1; GB1300685A; JPS5222138Y2

Abstract

A distribution valve for a device for evacuating and filling a vessel with gas. This valve comprises a rotatable part and a stationary part; the rotatable part having a number of ports which are connected to the vessels to be processed and the stationary part having a corresponding number of ports which are connected to the evacuating and filling apparatus. In order to prevent the entrance of air into the ports, a number of concentric circumferential grooves are provided in the confronting surfaces between the circumference and the center of the rotating and stationary parts. These grooves are maintained under a slight positive pressure by an inert gas supply.

Description

United States Patent [1 1 Notelteirs Jan. 30, 1973 1 1 SEAL ROTARY DISTRIBUTION VALVE U.S. Philips Corporation, New York, NY.

[22] Filed: March 23, 1971 [21] Appl. No.: 127,189

[73] Assignee:

[58] Field of Search .25 1/174, 180; 137/246, 246.14, l37/246.22, 250, 625.18, 625.11

[56] References Cited UNITED STATES PATENTS 2,918,938 12/1959 Kimball ..l37/625.l1 3,292,652 12/1966 Gallone "137/246 3/1969 Bartholet ..251/180X 5/1969 Faustini ..25l/180X Primary ExaminerWilliam R. Cline AttorneyFrank R. Trifari [57] ABSTRACT A distribution valve for a device for evacuating and filling a vessel with gas. This valve comprises a rotatable part and a stationary part; the rotatable part having a number of ports which are connected to the vessels to be processed and the stationary part having a corresponding number of ports which are connected to the evacuating and filling apparatus. In order to prevent the entrance of air into the ports, a number of concentric circumferential grooves are provided in the confronting surfaces between the circumference and the center of the rotating and stationary parts. These grooves are maintained under a slight positive pressure by an inert gas supply.

5 Claims, 2 Drawing Figures PAIENIED JAN 30 I975 T 3.713.461

SHEET 1 [1F 2 INVENTOR. VICTOR ROSALLIE NOTELTEIRS AGENT PATENTEDJAN 30 I973 3, 7 1 3 461 SHEET 2 OF 2 INVENT VICTOR ROSALLIENO rams kbEN'r SEAL ROTARY DISTRIBUTION VALVE The invention relates to a distribution valve for a device for evacuating and then filling with a halogencontaining gas, lamp or tube vessels for halogen lamps or halogen tubes, which valve mainly consists of two circular plates which are flat each on at least one side and which engage each other with their flat sides. During operation one plate is stationary while the other plate is capable of rotation. The two plates comprise a number of parts which open out to the flat sides, the ports in the stationary plate being connected to evacuating and filling apparatus, the ports in the rotating plate communicating with ducts connecting the exhaust tube of the lamp vessel or tube vessel to be treated. The flat side of the stationary plate comprise one or more lubricating grooves.

Such a distribution valve is known. In spite of the fact that in practice the grooves are filled with a grease which is suitable for vacuum application and the vapor pressure of which is low, leakage is found to occur between the valve parts. It is found in particular that air is sucked in between the valve parts, In that case it is difficult or even impossible to obtain good lamps in spite of adequate lubricating means and treatments of the latter.

The invention eliminates these drawbacks and makes it possible to obtain a good result all the same with the known distribution valves in the known devices. According to the invention, a distribution valve as described further comprises in the flat sides of the plate one or more circumferential grooves which can each communicate through an inlet duct with a duct or container containing an inert gas under pressure. Each groove furthermore comprise an outlet duct which connects the groove with a space in which a lower pressure prevails than in the duct or the container.

In the case of large leakage, a few units of neutral gas can enter the lamp or the vessel, it is true, however, that this has no detrimental effect on the halogen cycle in the lamp or tube.

According to an embodiment of the invention, an adjustable valve is present in the outlet duct, or the duct which communicates said outlet duct with the space. As a result of this the pressure of the gas in the groove or grooves is adjustable so that a minimum leakage can be achieved.

A further embodiment of the invention is characterized in that at least two gas grooves are present, one of the said gas grooves being present near the circumference of the valve, a lubricating groove being present on either side of said gas groove. It has been found that a very good seal is obtained in this manner.

According to a further embodiment of the invention, the assembly of lubricating grooves and intermediate gas grooves is present between the outer edge of the valve and the duct which can be made to communicate with the evacuating and filling apparatus.

An even better seal can be obtained if, according to an embodiment of the invention, a second gas groove is provided between the ducts which can be made to communicate with the evacuating and filling apparatus and the center of the valve.

In order that the invention may be readily carried into effect, one embodiment of the invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which FIG. 1 is a vertical cross-sectional view through a part of a device for evacuating and then filling with a halogen gas lamp vessels or tube vessels for halogen lamps or halogen tubes, comprising a distribution valve of which one part rotates, and I FIG. 2 is a plan view of the device shown in FIG. 1, taken on the line llII.

A distribution valve consists of a stationary part 1 and a rotating part 2 which parts bear on each other. A plate 7 is secured, by means of screws 6, to a part 5 of the device which during operation is also stationary. This plate 7 comprises a central pin 8 which extends in the part 1 of the valve and centers the said part perfectly. Around said pin 8 and against the valve part 1 is a pressure plate 9 comprising pins 10 with compression springs 11. Four projections 12 of the valve part 1 fit in grooves 13 of angle pieces 14 which are welded to the plate 5 so that rotation of the part 1 is impossible. Ten regularly distributed apertures 15 in valve part 1 communicate with pipe sections 16 which partly communicate with vacuum pumps 17 shown diagrammatically partly with containers 17A containing a halogen-containing inert gas.

A top plate 18 of the device is connected to a plate by means of four columns 19 welded thereto, which plate 20 is connected to a ring 22 by means of screws 21. The valve part 2 engages the said plate 20. The ring 22 is connected, by the screws 21, to an inner ring 23 of a ball bearing with balls 24, an outer ring of which, constituted by the

rings

25 and 26, is secured to the plate 5 by means of screws 27. Setting screws 28 in the ring 22 center the valve part 2. The valve part 2 comprises apertures 29 which, both as regards location and size, correspond to the apertures 15 in the valve part 2. Welded to valve parts 2 and above the apertures 29 are tubes 30 which are bent on their upper side and in which bulbs 31 of lamps which are first to be evacuated and are then to be filled with a halogen-containing gas can be connected in an airtight manner.

In the valve part 1, on the side which engages the valve part 2, three shallow grooves extending concentrically with the pin 8 are provided which are filled with a grease which has a low vapor pressure and is suitable for vacuum application and which grooves thus ensure a seal between the two valve parts. Between the two grooves 32 present near the outer edge of the valve, there is a groove 33 which communicates through a supply duct 34 with a container 35 containing a neutral gas, for example nitrogen, argon or krypton, under a slight positive pressure. On the other side of the part 1, the groove 33 communicates, through an outlet duct 36, with an adjustable valve 37 which communicates at one end again with the container 38. By adjusting the valve 37, the pressure ratio between the gas in the container 35 and the gas in the container 38 can be controlled.

A groove 39, similar to grooves 33, is present on the inside of the wreath of apertures 15; this groove communicates through ducts and 41, respectively, with container 35 and valve 37, respectively. By suitable choice of the positive pressure in the

inlet ducts

34 and 40 relative to the pressure in the

outlet ducts

36 and 41, which can be obtained by adjusting the valve 37, it is achieved that the neutral gas in the

grooves

33 and 39 obtains a slight flow towards the outside. This gas flow prevents air from coming between the flat valve parts 1 and 2 and ensures a perfect vacuum-tight seal of the space between the valve parts 1 and 2 which is as small as possible, (due to a finishing which is as accurate as possible). The lubricating ducts 32 known per se prevent the dry operation of the valve. lf desirable, a central lubricating chamber may be provided.

In the most unfavorable case a few units of inert gas may enter the lamps; however, this has no detrimental effect.

It has been found in practice that by using the gas grooves, a nearly complete seal is obtained between the valve parts. Although the gas grooves may be provided also in other places in the valve part, the described location has proved to give the best satisfaction. Dependent upon the requirements imposed, one gas groove may be sufficient.

What is claimed is:

1. A distribution valve for a device for evacuating and filling a vessel with another fluid comprising two circular plates having abutting surfaces, one of said circular plates being stationary and the other being rotatable about a common axis, said plates each having a plurality of ports at different angular locations around said axis and adapted to be aligned with each other upon relative rotation of the plates, means connecting the ports in the stationary plate to said evacuating and filling apparatus, means connecting the ports in the moving plate to the vessel, a plurality of circumferential grooves positioned in the surface of said stationary plate, a lubricant filling at least one of said grooves, means connecting a groove without lubricant therein to a supply of inert gas under pressure to fill said groove with inert gas, means connecting said gas filled groove to a container maintained at a pressure lower than that of said inert gas supply, thereby preventing air from entering said ports between the abutting surfaces of said circular plates.

2. A distribution valve as claimed in claim 1 further comprising an adjustable pressure valve in the means connecting said gas filled groove to said container.

3. A distribution valve as claimed in claim 1 comprising two of said gas filled grooves, one of said grooves being located near the circumference of said circular plates, said lubricating groove surrounding said gas filled groove near the circumference of said circular plates.

4. A distribution valve as claimed in claim 3 wherein one of said gas filled grooves is located between the circumference of said circular plates and said plurality of ports.

5. A distribution valve as claimed in claim 3 wherein one of said gas filled grooves is located between said plurality of ports and the centers of said circular plates.