US3623206A

US3623206A - Vacuum seal-off valve tool

Info

Publication number: US3623206A
Application number: US1162A
Authority: US
Inventors: Robert N Hager Jr
Original assignee: General Dynamics Corp
Current assignee: General Dynamics Corp
Priority date: 1970-01-07
Filing date: 1970-01-07
Publication date: 1971-11-30
Anticipated expiration: 1988-11-30

Abstract

A VALVE TOOL FOR REMOVING AND INSTALLING THE CAP PORTION OF A FITTING ATTACHED TO A CONTAINER OR VACUUM SYSTEM WHILE THE CONTAINER OR SYSTEM IS BEING EVACUATED. THE BELL-SHAPED BODY OF THE VALVE POSITIONS OVER THE PUMPDOWN FITTING DURING VACUUM PUMPING THEREOF. A SOCKET WRENCH ENCLOSED WITHIN THE VALVE BODY ENGAGES THE CAP PORTION OF THE FITTING FOR INSTALLATION OR REMOVAL THEREOF BY MANUAL OPERATION OF A HANDLE OUTSIDE OF THE VALVE BODY. A SHAFT EXTENDING THROUGH A SEAL IN THE VALVE BODY, CONNECTS THE SOCKET WRENCH TO THE HANDLE. A PORT LOCATED IN THE VALVE BODY PROVIDES PASSAGE MEANS FOR EVACUATING GASES FROM THE SYSTEM OR CONTAINER.

Description

1971 R. N. HAGER, JR

VACUUM SEAL-OFF VALVE TOOL Filed Jan. 7, 1970 4 wfiy uwQwMM/%\ mm w/\ 6 Q /ZZ? 2 w\ mm 2\\ I way Qm w F W ROBERT ATTORNEY United States Patent 3,623,206 VACUUM SEAL-OFF VALVE TOOL Robert N. Hager, Jr., Gainesville, Fla, assignor to General Dynamics Corporation, San Diego, Calif. Filed Jan. 7, 1970, Ser. No. 1,162 Int. Cl. B231) 19/04 US. Cl. 29-440 6 Claims ABSTRACT OF THE DISCLOSURE A valve tool for removing and installing the cap portion of a fitting attached to a container or vacuum system while the container or system is being evacuated. The bell-shaped body of the valve positions over the pumpdown fitting during vacuum pumping thereof. A socket wrench enclosed within the valve body engages the cap portion of the fitting for installation or removal thereof by manual operation of a handle outside of the valve body. A shaft extending through a seal in the valve body, connects the socket wrench to the handle. A port located in the valve body provides passage means for evacuating gases from the system or container.

BACKGROUND OF THE INVENTION In the field of cryogenics, transfer lines employed to conduct cryogens to and from a container are preferably insulated to minimize heat transfer. An outer jacket or pipe surrounds the transfer line providing an air gap between the jacket and line. The air is then evacuated, creating a vacuum to effectively insulate the transfer line.

Evacuation is usually accomplished by connecting a vacuum pump to a valve installed on the jacket of the transfer line. The valve is opened during pump-down and subsequently closed after the air has been evacuated. The valves used for such purposes are expensive to construct and are costly to use since they must remain on the jacket after pump-down to maintain the required vacuum pressure.

Shipping containers for instruments and the like, are sometimes required to be evacuated in order to protect the instrument during transit. Here again valves are employed to accomplish evacuation and sealing of the container.

The present invention is designed to eliminate the need for a permanently installed valve by providing an inexpensive fitting in a system or container to be evacuated, and opening and closing the fitting while purging air from the system or container.

BRIEF SUMMARY The valve tool of the present invention is adapted for opening and closing a pump-down fitting on a system or container to be evacuated. The tool comprises a hollow body enclosing a socket type wrench mounted on one end of a shaft. The shaft extends outwardly through the wall of the body for manual operation by means of a handle mounted on the opposite end thereof. A port communicating with the hollow interior of the body connects to a vacuum pump when the valve device is in use to evacuate the gases from a cryogenic system or other system, package, or container. Seals are provided in the body around the shaft and in the body base to seal against leakage of gases into the body interior during vacuum pumping. Positive seal-off of the pump-down fitting is accomplished by threading a nut on the fitting by manual manipulation of the valve tool handle while the valve tool is under vacuum pressure.

[It is an object of the present invention to provide a valve tool to cap and uncap a fitting on a jacket or container during vacuum pumping thereof.

3,623,206 Patented Nov. 30, 1971 Another object of this invention is to provide a valve tool which is adaptable for use with various size fittings.

Still another object of this invention is to provide a valve tool which is simple to operate and economical to use.

A further object of this invention is to provide a valve tool having novel friction holding means embodied in the wrench portion thereof.

DESCRIPTION OF DRAWINGS Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

@FIG. 1 is a perspective view showing the valve tool of the present invention assembled on the jacket of a transfer line with the vacuum port thereof connected to a vacuum pump; and

FIG. 2 is an enlarged longitudinal cross-section through the valve tool and a fragment of a pipe jacket.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENT A body member 10 is substantially an inverted cup having a closed upper end 12, a cylindrical wall 14, and an open-ended base 16. Base 16 is provided with a groove 18 in which an O-ring seal 20 is seated. Upper end 12 is axially bored at 22 having a countersunk bore portion 24 opening to the exterior of body member 10. A shaft 26 extends into the hollow interior of the body member 10 through the bore 22. Shaft 26 is axially movable and rotatably movable in the bore 22. An O-ring 28 surrounding shaft 26, is urged into intimate contact with shaft 26 and the wall of the countersink bore 24 by a packing gland 30. A cap 32 having internal threads 34 engages external threads 36 on the upper end 12 of the body member 10. Tightening of the cap 32 on the threads 36 exerts pressure on the packing gland 30 which in turn effects an increase in the sealing pressure of the O-ring 28. A handle 38 secured to the shaft 26 outside of the body member 10 provides convenient means for transmitting rotational and linear movement to a fitting capping means within the hollow interior of the body member 10.

The end 40 of shaft 26 enclosed by the body member 10 is preferably square in cross section having a spring biased ball 42 projecting from one of the flat faces thereof for frictional engagement with a detent in a fitting capping means or socket type wrench 44. Thus socket wrenches 44 of various sizes may be substituted on shaft 26 as required to fit a particular size nut. Socket wrench 44 is provided with a hexagonal wrenching recess 46 adapted to engage the hexagonal wrenching surfaces of a nut C or the like. A circumferential groove 48 in the walls of the recess 46 is provided to receive a split wire retainer ring 50. Ring 50 is adapted to grip nut C, retaining it in recess 46 of socket wrench 44 until installation on the fitting F.

Projecting from the wall 14 of body member 10 is a nozzle 52 having a bore 54 communicating with the hollow interior of the body 10. A hose 56 connects to the nozzle 52 at one end and to a vacuum pump 58 at the opposite end thereof.

OPERATION Exemplary of a system in which the valve tool of the present invention is advantageously employed is the cryogenic conductor P shown in FIG. 1 of the drawings. Conductor P is enclosed by a jacket I. Jacket J is provided with a raised boss or pad B having a screw threaded opening H in which a vacuum pump down fitting is mounted.

In preparation for evacuating gases from around conductor P, the seal S is first placed on the cone portion F of the fitting F. Seal S is a thin sheet metal cone fabricated from a malleable metal such as copper and is retained on the fitting F by frictional engagement therewith. The cap or nut portion C of the fitting F is inserted in the socket Wrench recess 46 and retained in position by the retainer ring 50. It is to be noted that in order to facilitate insertion of the nut C in the socket wrench 44, shaft 26 may be moved linearly to position socket wrench 44 outside of the hollow interior of body member 10. After the proper size socket wrench 44 is installed on the shaft 26 and the nut C is inserted therein, shaft 26 is retracted to the position shown in FIG. 2.

Body member with shaft 26 retracted, is positioned over the fitting F with the base portion 16 thereof engaging the pad B of the jacket J. Hose 56 is connected at one end to the nozzle 52 of body member 10 and the vacuum pump 58 at its opposite end. Vacuum pump 58 is then activated to begin pump down of the system being evacuated. Upon completing the pump down operation, and with the vacuum pump operating continuously, shaft 26 is moved inwardly of body member 10 until the threads of nut C engage the threads of fitting F. Shaft 26 is then rotated by means of the handle 38 until nut C is tightened on fitting F. If desired, a torque wrench may be substituted in place of handle 38 to precisely torque nut C onto fitting F. Once nut C has been properly tightened, vacuum pump 58 is inactivated and hose 56 disconnected from body member 10 to permit removal of the valve tool from the jacket I.

It will be apparent to one skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. A vacuum system sealing tool comprising:

a generally cup-shaped body having an end wall, an

open end and a generally cylindrical side wall,

a rotatable and axially movable shaft extending through said end wall substantially along the axis of said body,

the rim around the open end of said cup-shaped body lying in a plane generally perpendicular to the axis of said body,

said rim having a groove surrounding said open end,

sealing means positioned in said groove projecting beyond said rim,

said body adapted to be positioned with said seal in contact with a planar surface surrounding an evacuation fitting mounted in the wall of a vacuum container,

nozzle means in said side wall through which said body and vacuum container may be evacuated,

the end of said shaft within said body adapted to releasably support a fitting cap, and

means to move said shaft to position said fitting cap into sealing engagement with said evacuation fitting.

2. The vacuum system sealing tool of claim 1 wherea second sealing means is provided in said end wall around said shaft.

3. The vacuum system sealing tool of claim 2 wherein:

a handle is provided on said shaft for transmitting rotary and axial movement thereto.

4. The vacuum system sealing tool of claim 3 wherein:

said releasable fitting cap holding means of said shaft is removably connected to said shaft.

5. The vacuum system sealing tool of claim 4 wherein:

said releasable fitting cap holding means is provided with retaining means for frictionally supporting a fitting cap therein.

6. The vacuum system sealing tool of claim 5 wherein:

said rim of said body is a planar surface.

References Cited UNITED STATES PATENTS 1,920,240 8/1933 Brady 29-240 UX FOREIGN PATENTS 1,102,786 3/1961 Germany 2924O ANDREW R. J UHASZ, Primary Examiner L. GILDEN, Assistant Examiner U.S. C1. X.R. 29203 U