US3650429A

US3650429A - Systems for sealing enclosures

Info

Publication number: US3650429A
Application number: US5315A
Authority: US
Inventors: Pierre Ribout
Original assignee: Thomson CSF SA
Current assignee: Thales SA
Priority date: 1969-02-04
Filing date: 1970-01-23
Publication date: 1972-03-21
Anticipated expiration: 1989-03-21
Also published as: DE2004642A1; FR2031689A5; GB1263444A

Abstract

A closing arrangement for closing the exhaust tip of evacuated enclosures comprising two flanges, one of which is associated with the tip and a central plug associated with the other flange and which closes the tip. Ducts are provided for connecting the tip with the outside. A joint is provided between the plug and the tip and flexible bellows interconnect the two flanges.

Description

United States Patent Ribout [451 Mar. 21, 1972 [541 SYSTEMS FOR SEALING ENCLOSURES 2,683,614 7/1954 Warren ..l4l/65 x [72] Inventor: Pierre Ribout, Paris, France FOREIGN PATENTS OR APPLICATIONS [731 Assignw 722,303 1/1955 Great Britain ..141 I65 [22] Filed: Jan. 23, 1970 Primary Examiner-Allen N. Knowles [21] Appl' 5315 Assistant Examiner-Edwin D. Grant Attorney-Kurt Kelman [30] Foreign Application Priority Data Feb. 4, 1969 France ..6902398 [571 ABSTRACT A closing arrangement for closing the exhaust tip of evacuated [52] US. Cl. ..220/2.l R, 53/818,218?!5 1/6256, enclosures comprising two flanges, one of which is associated I l 25 1/ b j with the tip and a central plug associated with the other flange i 141/65 and which closes the tip. Ducts are provided for connecting h b 151.285/226' the tip with the outside. A joint is provided between the plug and the tip and flexible bellows interconnect the two flanges. 56] v Reierences Cited 9 Claims, 7 Drawing Figures UNITED STATES PATENTS 1,728,034 9/1929 B01 1fl/ 5 PATENTEDMARZ] I972 SHEET 1 OF 4 wvzvrm flame meow- PATENTEDMAR21 I972 sum 2 0F 4 Fig. 5

wan/r lease mam y kesnr PAIENTEDMARm 1912 sum u UF 4 wvewrm flaw: Rmwr 7 1 1 SYSTEMS FOR SEALING ENCLOSURES The present invention relates to vacuum tight enclosures, for example vacuum tubes.

It is an object of the invention to provide an enclosure having a strong exhaust tip arrangement which makes readily possible its rapid repeated connection to or disconnection from apumping set.

According to the invention, there is provided an arrangement for sealing the exhaust tip of an enclosure comprising a first flange having means for a tight connection to said tip, a second flange matched to said first flange and arranged for connection to a pumping set, a plug associated with said second flange for closing said tip, said plug and said second flange thus forming an assembly, ducts extending through said assembly for connection of said tip to said pumping set, and flexible bellows connecting said assembly to said first flange.

For a better understanding of the invention and to show how the same may be carried into effect reference will be made to the drawing accompanying the ensuing description and in which:

FIG. I illustrates an axial section through a portion of an evacuated enclosure provided with a sealing arrangement in accordance with the invention, ready for assembly on a pumpmg set;

FIGS. 2, 3, 4, illustrate three stages of the invention;

FIG. 5 illustrates, in axial section, a modification of the structure according to the invention; and

FIGS. 6 and 7 illustrate in section a portion of a further embodiment of the invention in two different stages of the application thereof.

In the various figures, similar reference numbers designate similar parts.

The device shown in FIG. 1 illustrates a sealed enclosure 1 terminated by a metal tip 2 carrying at its end a flange 3 which may be integral therewith and machined at the same time as the tip or otherwise affixed on the tip in a tight manner.

The flange 3 is connected to a flange 4 by a flexible and tight bellows 5, for example of corrugated metal, which can be for example brazed at 6 and 7 to the

flanges

3 and 4 respectively and which laterally seals off the arrangement while allowing the two flanges to be readily moved towards one another. A central plug 8 is screwed into the flange 4 at one of its ends, whilst the other end is inserted into the tip 2, thus enabling the

flanges

3 and 4 to be aligned and any suitable component or assembly of components, such as an electrongun, for example, to be centered axially of the system, prior to the introduction thereof into the vacuum enclosure. FIG. 1, also shows the output of a pumping set 11, equipped with a flange 10 or any other suitable arrangement for a tight con nection to the flange 4, for example with interposition of a sealing joint 12.

Pumping orifices 13 are formed in the plug 8 and in the flange 4.

The

flanges

3, 4 and I are respectively provided with a plurality of holes 18, 19 and 20, the holes 18 and 20 being smooth-bored and the holes 19 screwed. In these holes locking or

dowel screws

15, 16 and 17 are inserted as shown in the figures.

FIG. 2 illustrates how the vacuum enclosure is connected to the output 11 of the pumping set when it is desired to evacuate this enclosure.

First the dowel screws 15, which prevent the flexible bellows from being compressed under the effect of atmospheric pressure, are placed into holes provided to this effect in the flange 3. A metal seal 12 located between the flanges and 4 is squashed together until complete sealing is achieved, this by means of the locking screws 16. The pumping is then started. The gases are evacuated from the enclosure 1 through the pumping orifices 13.

When the vacuum level required has been reached (FIG. 3), the dowel screws 15 are removed. The metal seal 9 is then compressed by the plug 8 squashed by the clamping screw 17 which are tightened. The enclosure is thus sealed off and may be disconnected from the pumping set by removing the screws 16 as shown in FIG. 3.

FIG. 4 illustrates the preparation of the assembly for a fresh pumping cycle. The evacuated enclosure 1 is opened by releasing the screws 17. The dowel screws 15 (see FIG. 2) are then put in position. The central plug is removed in order to enable the new metal seal 9 to be introduced. The plug is then again placed in the position shown in FIG. 2. A new pumping cycle can dress be commenced.

FIG. 5 illustrates a variant embodiment of an exhaust tip closing assembly in accordance with the invention.

The pumping orifices 13 are formed in FIG. 1, in the wall of a hollowed plug 9. Instead of that in FIG. 5 longitudinal passages 21 are formed in a solid plug. This may allow a more rapid evacuation of the gases contained in the enclosure. In addition, there are respectively provided in the mutually opposed faces of the plug a projection 22 and a cavity matched to each other, which make it possible to guide and more effec tively squash the seal 9. Similar projections and notches 23 are provided on the opposite faces of the

flanges

4 and 10 for the same reason.

FIG. 6 shows a modification of the exhaust tip closing arrangement according to the invention before the tip has been actually sealed and FIG. 7 shows the same arrangement after the sealing has been performed.

The embodiment of FIGS. 6 and 7 has the advantage of providing a sealed enclosure which is less cumbersome. It has the further advantage that the arrangement for sealing the tube may be removed after the sealing has been performed and immediately used for sealing another tube, only the plug actually closing the tip remaining attached to the tip.

The enclosure 1, for example a tube envelope, shown in FIGS. 6 and 7 comprises an exhaust tip 2 to which a flange 3a is integrally fixed. On the flange 3a is mounted, by means of dowels A, a further flange or rim 3b, a suitable joint 19 being inserted for tightness purposes between the flange 3a and the rim 3b. A flange or rim 4b is mounted on the flange 10 which is mounted at the input of the pumping set 11. The

rims

3b and 4b are interconnected by bellows 5, which are, for example, soldered to the

rims

4b and 3b respectively at

suitable shoulders

6 and 7 formed therein.

The rim 4b has a projecting portion 40 which on its outward end face carries a plug 41 which is fixed thereto by means of dowel screws D. Dowel screws 42 are provided for centering the assembly carried by the flange 10. A metal joint 9 is placed on the end face of the plug 41. A bolt 44, carrying

nuts

45 and 46, interconnects the

rims

3b and 4b, for determining the distance there between and preventing the bellows 5 from collapsing before the evacuation of the enclosure 1 is completed.

During the pumping out operation, the gas contained in the enclosure 1 flows through the opening 13 provided in the projecting portion 40 of the rim 4b.

When the desired vacuum has been achieved in the enclosure 1, the exhaust tip is closed, as shown in FIG. 7.

The nuts 46 are completely unscrewed, the bellows 5 collapse and the joint 9 is squashed between the flange 3a and the plug 41.

The assembly can then be removed from the enclosure 1. To this end dowels B are first unscrewed and the assembly is thus disconnected from the pumping set. Centering screws 42 are removed, dowels C are then put in place, and dowels D and dowels A finally removed.

As may be seen, the enclosure 1 is then closed only with the plug 41.

The invention is applicable to any scaled enclosure which has to be pumped or filled with any kind of gas, especially if rapid and repeated mounting on and dismantling from a gas pumping or filling set is desired.

Of course, the invention is not limited to the embodiments described and shown. In practical various kinds of joints or flanges can be used. Also the flange 3 of the exhaust tip closing arrangement may be integral with the tip 2 or the closing arrangement may comprise a flange member 3 which is in any suitable manner tightly connected to the tip 2.

What is claimed is:

1. An arrangement for sealing the exhaust metallic tip of an enclosure comprising: a first flange having at least one portion tightly connected to said tip, a second flange matched to said first flange and arranged for connection to a pumping set, a plug associated with said second flange for closing said tip, said plug and said second flange thus forming an assembly, ducts extending through said assembly for connection of said tip to said pumping set, and flexible bellows connecting said assembly to said first flange.

2. An arrangement as claimed in claim 1, wherein said plug is provided with a shoulder for inserting a seal between the end of said tip and said shoulder.

3. An arrangement as claimed in claim 2, further comprising means for temporarily preventing said seal from being squashed between said plug and said tip by a pressure exerted from outside on said arrangement.

4. An arrangement as claimed in claim 1, further comprising means for rigidly connecting said assembly to said first flange.

5. An arrangement as claimed in claim 1, wherein said first flange is wholly integral with said tip.

6. An arrangement as claimed in claim 1, wherein each of said flanges comprises a first and a second portion disconnectable from each other, said first portion of said first flange being said at least one portion tightly connected to said tip, said plug being associated with said second portion of said second flange and said bellows extending between said second portions of said flanges.

7. An arrangement as claimed in claim 6, wherein said plug is disconnectably associated with said second portion of said second flange.

8. A sealed enclosurehaving an exhaust tip closed with an arrangement as claimed in claim 1.

9. A sealed enclosure having an exhaust tip closed with a plug as claimed in claim 7.

k k k t

Claims

8. A sealed enclosure having an exhaust tip closed with an arrangement as claimed in claim 1.