US3545500A - Vacuum system - Google Patents

Description

O Umted States Patent u 13,545,500

[72] lnventors ligbeell'lt J-BOVO [56] References Cited Arnold E. Westlund,Jr., Gloucester, "9 l I] 5 2 ENTS Massachusetts reat rltam 55/309 [2l 1 Appl. No. 692,499 Primary Examiner-Houston S. Bell, Jr.. [22] Filed Dec. 21, 1967 Attorneys-Norman J. OMalley and Laurence Burns [45] Patented Dec. 8, 1970 [73] Assignee Sylvlnla Electric Products Inc.

r corporation Delaware ABSTRACT: A vacuum system comprising a two-phase pumping arrangement that is connected over a main conduit to a remotely dis osed evacuation s stem. The main conduit is [54] VACUUM SYSTEM normally closed-Exfi during the first phase of evacuation by a 4 cmmsl Drawing plunger associated with an electrical solenoid. A screened [52] [1.8. CI. 141/65, detour conduit is provided around the blocked main conduit.

, 55/312, 55/428, 55/511 Thereby, the first pump phase evacuates air from the article [5| 1 Int. Cl. B65b 31/04 over the screened detour path, filtering out unwanted particles [50] Field of Search 141/93, 65, that are collected in a trap well positioned adjacent the screen 66. 8.286(lnquired); 55/270, 309, 312, 313, 314, 428, 429, 432, 433, 503, 5i1(lnquired);62/(lnquired); 230/(lnquired); l37/(lnquired) area. The second and final phase of evacuation is initiated after the solenoid is energized to remove the block from the main conduit.

VACUUM SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention i n the initial surging cycle, the evacuation of air and/or other gases from the article 14 collects residue or particle's left This invention is directed to hydraulic vacuum systems but 5 more specifically to vacuum pumps where an article fitted to the pumping system can be evacuated from an atmospheric condition to a given vacuum. Normally, a device of this type employs a series of pumps that provide a rough and fine pumping combination to achieve a desired vacuum of an article.

2. Description of the Prior Art Articles of work that require evacuation such as bell jars, lamp envelopes, etc. are normally attached directly to a central orifice of a pumping system. A series of interconnected mechanical and diffusion pumps are then operated to evacuate gas from the article to a desired vacuum. Usually a first pumping-down called a p urge or rough-pump is accomplished by a mechanical pump. This initial surge of evacuated currents frequently sweeps .or cleans out any sediment or residue lefl in the article from a previous step of fabrication. The sediment is drawn fromthe article to an evacuation port by way of the internal mechanism of the pump. The particles collect within the pump mechanism which necessitates frequent repairs, Also, constant ingestion of these particles can necessitate, early replacementof the pump. Even with expensive practices such as air cleaning of the article prior to evacuation failed to reduce the costly downtime and early replacement of the pump.

SUMMARY or THE lNVENTlON In our invention we have overcome these problems by designing a built-in sediment trap fully operativeduring the first purge cycle of the evacuation of the article. 7 During the first cycle, a new'route from the article to pump is established by blocking the main route. This new route is provided with a screened trap that prevents residue and sediment from reaching the pump. This purge cycle isof short duration. and at its termination automatically actuates a fine pumping or diffusion pump cycle.

Just prior to initiation of the fine pumping cycle, the block is removed from the main route. This allows a direct, unscreened path from the article to the pump providing high speed evacuation of the article.

This unique system provides a trouble-free cleansing ar' rangement of an article for an unlimited usage in vacuum systems.

These and other objects, features and advantages of the invention will be apparent from the following specification when taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a schematic view of an evacuation system showing in particular the article and pumping source and the interconnected piping therebetween.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, ourembodiment of a sediment trap comprises a piping system of standard tubular configuration. The pumping system generates from a main pumping source 10 to an article manifold 12. in a specific example we describe and illustrate a leak detector apparatus showing 'how a sediment of our design would function.

In a leak detector operation, series of pumps are utilized for attaining a desired vacuum withinan article. The two pumps most commonly usedare a standard mechanical pump and a diffusion pump. In the first phase of pumping the mechanical pump is initiated to introduce a pumping cycle where the infrom a previous operation and carries this sediment back to the pumping source '10.

To prevent this sediment from reaching the intricate pumping mechanism we detour the main straight route from article topump. The completetubular piping system can be clearly seen in the illustration of the drawing where a straight main pipe 16 having one end affiired to the pumping source 10 and the other end fitted with a short upturned run 18. An article manifold adjustable fitting 12 is positioned thereto, with a conventional knurled closure ring 20 capable of being rotated to receive and hold an article.

The main pipe l6 is provided with two spaced apart shortrun legs 22 and 24 extending down fro-m the pipe 16. The legs 22 and 24 mate with coinciding short legs 28 and 30 of a sediment trap 26. The legs 28 and 30 are extensions of a straight The legs 22 and 24 are joined to the legs 28 and 30 by standard compression rings 34 and-36. The joining of legs 22 and 24 to legs28 and 30 must be attained'with complete air tight joints and is accomplished by using compressible gaskets between the joi'ned ends. ln'the fitting of leg 24 to leg 30, a simple 0-ring gasket 38 is placed between the ends and then compression ring 36 is affixed to completely seal this joint.

The joining of legs 22 and 28 are done in asimilar manner with the exception that a screen 40 is spaced between two 0- ring gaskets 42 and then'the compression ring 34 is secured thereto.

A lower extending leg 44 in register with leg 28 defines a sediment well 46 which is provided with a removable screw To complete the device, asolenoid 50 having a coil 51 is fitted to the top area of the main pipe '16. The solenoid is provided with "an internal blocking plate 52 fitted within guideways 54 of the pipe 16 and guide between the coil 51 of the solenoid 50. Normally, the blocking plate 52 is spring urged in the opening of pipe 16 by a spring 56.

be described. An article 14 is fitted into the manifold 12 by rotation of the knurled closing ring 20. Articles of different configuration can be accepted by interchangeable manifold fittings. As mentioned previously, the pumping source is initiated with a purge flush accomplished by a mechanical pump. It may be noted at'this time that the main pipe 16 is closed by block 52. Therefore air evacuated from the vessel or article 1.4 is drawn over the detour path, designated in the drawing by the broken arrows. This first rush of air carrying any particles of residue follows the bypass piping 24, 30, 32 and 28 where the particles are trapped by the screen 40, positioned between legs 22 and 28. The filtered air continues through the screen and completes its circuit back to the pumping source 10.

At this particular time the operation, the mechanical pump is isolated from the system and a diffusion pump, a part of the pumping source 10, is put into operation. Just prior to the operationof the diffusion pump the solenoid 50 is activated thereby removing the block by means of energizing the coil 51. As mentioned previously, the diffusion pump accom plishes the desired vacuum of the article in this case a vacuum in the vicinity of 10- microns. With the block 52 removed from the main pipe 16 a direct run from article to pump is established where residue clear air is rapidly drawn back to the pumping source 10. After the article has been evacuated to the desired vacuum, the analysis of the part being evacuated is made, then the part and system is put back to atmosphere. A new article can be fitted to the manifold and the operation is repeated.

During isolation shutdown .of the pumps, and during attachment of a new article to the manifold any sediment caught A complete sequence of an evacuation of an article will now' An added precaution to catch and retain minute sediment particles in the traparea is accomplished by coating the inner walls of the trap area with a low vapor pressure grit catching grease. When this grease is used the complete trap piping has to be taken 011' and cleaned, this isaccomplished by removing the compression rings 34 and 36. The trap operates normally without the grease, but if added protection is required, this can be utilized.

It is apparent that modifications and changes can be made within the spirit and scope of the instant invention, but it is our arranged so that said blocking means can be bypassed; filter means fitted within said detour path;

gases from the article to be evacuated being directed through said detour path and hence said filter when the mechanical pump is actuated and thence being directed through said main evacuation line when said diffusion pump is actuated, whereby extraneous particles are filtered from the gases andprevented from entering the pumping source when said mechanical pump is actuated.

2. The vacuum pumping system according to claim 1 wherein a sediment trap is disposed below said filter means and includes a removable capped well, whereby particles caught in the screen are collected therein.

3. The vacuum system according to claim 1 wherein said blocking means comprises an electrical solenoid having a plunger defined as a block, said plunger normally spring urged to block said main evacuation line and when energization of said solenoid thereby removes said plunger from said main evacuation line after said rough pumping cycle is completed.

4. The vacuum system according to claim 1 wherein said filter means is a screen.

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