US3350106A

US3350106A - Packing gland

Info

Publication number: US3350106A
Application number: US419859A
Authority: US
Inventors: Edgar L Wheeler
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-12-21
Filing date: 1964-12-21
Publication date: 1967-10-31
Anticipated expiration: 1984-10-31

Description

E. 1.. WHEELER 3,350,106

PACKING GLAND Oct. 31, 1967 Filed Dec- 21, 1964 INVENTOR. EDGAR L. WHEELER 6mm: 6 dfi u a/ ATTORNEYS.

United States Patent 3,350,106 PACKING GLAND Edgar L. Wheeler, 5636 Blanco Ave, Woodland Hills, Calif. 91364 Filed Dec. 21, 1964, Ser. No. 419,859 6 Claims. (Cl. 277-59) This invention relates generally to packing glands and more particularly to a novel packing gland for passing a rotatable member into an enclosure under a pressure different from the exterior pressure.

In both commercial and research chemical laboratories it is oftentimes desirable to be able to mix or stir the contents of a flask or other enclosure while maintaining the pressure of ingredients in the enclosure at values to which they would normally be subject were the flask sealed at all times. For example, there are situations in which a relatively high vacuum is maintained in a flask and it is normally difficult to stir or mix the ingredients in the flask without losing some of the vacuum as a consequence of leakage when a stirring means is introduced and operated. In other instances, the ingredients may be under a pressure considerably greater than the ambient pressure and again it becomes difiicult to stir the contents without a loss of this higher interior pressure.

With the foregoing in mind, it is accordingly a primary object of the present invention to provide a novel packing gland structure designed, in its preferred embodiment, to be received within the neck of a flask and through which a stirring means is passed to enable stirring of the contents within the flask while maintaining the pressure difference that would exist between the interior pressure of the flask and the exterior were the flask at all times completely hermetically sealed.

More particularly, it is an object to provide a packing gland for passing a rotatable member such as a suitable stirring means into a flask to enable stirring of the contents of the flask while these contents are under a relatively high vacuum without any leakage of exterior gases into the flask.

Another object is to provide a packing gland meeting the foregoing object which will also prevent a loss of a greater interior pressure in the flask to the exterior dur ing a stirring operation.

A particularly important object is to provide a novel packing gland in which a scaling is effected about a ro tatable member even though the member may be rotated at high speed, between an interior pressure within an enclosure and an exterior pressure wherein the effectiveness of the sealing increases in proportion to the pressure difference existing.

Briefly, these and many other objects and advantages of this invention are attained by providing a housing structure for connection to a flask or other enclosure. In the preferred embodiment of the invention, this housing structure defines an interior chamber and includes inlet and outlet bores having first ends extending into the chamber and second ends communicating respectively with the interior of the enclosure and the exterior thereof. A stirring means is introduced through thetwo bores to extend from the exterior to the interior of the enclosure.

Within the chamber there are provided first and second resilient sleeve structures surrounding the first ends of the bores and extending along portions of the stirring means given distances and thence engaging the peripheries of these portions in sealing relationship. The chamber it self is filled with an incompressible fluid, preferably in the form of lubricating oil, which serves to communicate pressure to which the interior of the first sleeve is sub ject to the exterior of the second sleeve thereby main taining the second sleeve in tight sealing relationship with the rotatable member when the pressure within the enclosure is greater than the exterior pressure. Similarly, this incompressible fluid will transmit pressure to which the interior of the second sleeve is subject to the exterior of the first sleeve to maintain the first sleeve in tight sealing relationship with the stirring means when the exterior pressure is greater than the interior pressure within the enclosure.

The incompressible fluid in the form of an oil as stated serves the additional function of lubricating the engaging areas of the sleeves with the stirring means.

A better understanding of the invention will be had by now referring to the preferred embodiment thereof as illustrated in the accompanying drawings, in which:

FIGURE 1 is a perspective view of a flask incorporating the packing gland of this invention; 7

FIGURE 2 is an enlarged view of the packing gland partly in cross-section taken in the direction of the ar rows 2-2 of FIGURE 1; and

FIGURE 3 is a further enlarged fragmentary view part ly in cross-section of a portion of the structure illustrated in FIGURE 2.

Referring first to FIGURE 1 there is shown a flask 10 having an upper neck opening 11. Positioned above the opening 11 is a housing 12 terminating at its lower end in a shaped plug portion 13 receivable in the neck portion of the opening 11. Suitable O-

type sealing rings

14 and 15 are disposed about the plug 13 to insure a pressure tight seal between the neck of the flask and the housing structure.

The upper end of the housing structure 12 includes a cap 16, preferably of plastic material, through which extends a stirring means in the form of a rod 17 terminat ing at its upper exterior end in a suitable rotating means such as a motor 18. The lower end of the stirring rod 17 extends within the flask 10 as shown and terminates in a lateral structure such as a propeller 19 to effect mixing of the contents of the flask upon rotation of the rod.

Referring now to FIGURE 2, details of the packing gland structure within the housing 12 will be evident. As shown, the cap 16 is threaded into the upper end of the housing 12 as at 20 and includes a sealing O-ring 21 to define within the housing an inner chamber 22.

The housing and cap structure are provided with inlet and outlet bores 23 and 24 having first ends extending into the chamber 22 and second ends communicating respectively with the interior of the flask 10 and the exterior thereof. It will be noted that the stirring rod 17 is of lesser diameter than these bores.

The first end of the inlet bore 23 terminating within the chamber 22 is designated 25' and includes an annular Teflon insert 26. A first resilient sleeve 27, preferably formed of surgical type rubber, surrounds bore 28 at one end and has its other end extending for a given distance axially along the rod 17 and thence surrounding the periphery of the rod in sealing engagement therewith as indicated at 29.

Similarly, the first end of the second bore 24 in the cap structure 16 is indicated at 30' extending into the chamber 22 and is provided with a Teflon insert 31 and resilient sleeve 32. This sleeve surrounds the bore and extends axially along a portion of the rod 17 in opposed relationship to the sleeve 27 and thence engages about the rod 17 in sealing relationship. The bore ends, Teflon inserts, and resilient sleeves are entirely symmetrical as described, but are disposed in opposing relationship within the chamber 22. The Teflon inserts prevent whipping movements of the rod 17 when rotated at high speeds.

FIGURE 3 illustrates in greater detail the first end 25 of the bore 23 together with the Teflon insert structure 26 and sleeve 27. Since the diameter of the stirring rod 17 is less than the inlet bore 23, the interior of the sleeve 3 27 will be subject to the interior pressure of the flask This pressure is designated P1 in FIGURES 1, 2, and 3.

Similarly, with reference again to FIGURE 2, the interior of the second resilient sleeve 32 will be subject to the exterior pressure designated P2. The inner chamber 22 is filled with an incompressible fluid such as lubricating oil designated by the arrow 33. The exterior of the

sleeves

27 and 32 are thus subject to the pressure of this incompressible fluid.

In operation, assume first that the pressure P1 in the flask 10 is considerably less than the exterior pressure P2 outside of the flask and housing. Such a condition would obtain if the ingredients being mixed in the flask were under high vacuum. In this case, the incompressible liquid 33 in the chamber 22 will be subject to the exterior pressure P2 since this pressure is communicated to the fluid through the enlarged outlet bore 24 and the resilient nature of the sealing sleeve 32. The interior of the first sleeve 27 on the other hand is at a greatly reduced pressure corresponding to the pressure P1 in the flask. Therefore the greater exterior pressure will be communicated by the fluid 33 to compress the annular sleeve 27 into tight sealing relationship with the stirring rod 17. The greater the pressure differential, the greater will be the pressure exerted on the sleeve. The rod 17 may be rotated at a high speed and the seal maintained, the incompressible fluid in the form of a lubricating oil serving to lubricate the engaging interior surfaces of the sleeve with the rod portion passing therethrough.

It now the presure P1 within the enclosure or flask 10 should be greater than the ambient pressure P2, this increased pressure within the enclosure will be communicated to the incompressible fluid 33 in the chamber 22. The manner in which this takes place will be evident in FIGURE 3 wherein, when the pressure P1 is greater than the ambient pressure, there will be a tendency for the sleeve 27 to bow outwardly as indicated by the dotted lines 27. Since the fluid within the chamber is incompressible, this increased pressure is communicated through the fluid to the second sleeve 32 of FIGURE 2 thereby causing it to engage more tightly the rod 17 in sealing relationship. The contents of the enclosure may thus be stirred while maintaining the pressure within the enclosure.

It should be noted with respect to the foregoing that the axial distance the sleeve extend along portions of the stirring rod 17 is suificient to allow resilient movement of the mid-portions of the sleeves so that pressure differences may be communicated by the fluid between the respective sleeves without the engaging end portions of the sleeves leaving the rod 17. Thus, there is not any possibility of contamination of the fluid 33 in the chamber by the contents within the enclosure regardless of whether the pressure in the enclosure is greater or less than the ambient pressure.

From the foregoing description, it will thus be evident that the present invention has provided a greatly improved packing gland particularly suitable for use with flasks and the like to enable the contents thereof to be stirred and yet maintain the pressure within the flask as would exist were the flask completely hermetically sealed.

While the invention has been described in conjunction with chemical flasks and the like, it will be evident that the packing gland structure may be used to maintain a pressure within any suitable enclosure into which a mechanism extends for stirring the contents of the enclosure or otherwise treating the same. The packing gland is therefore not to be though of as limited to the exact application or structure set forth.

What is claimed is: v

1. A packing gland for passing a rotatable member into an enclosure having a pressure different from the exterior pressure comprising: a housing defining an inner chamber and having inlet and outlet bores communicating at first ends with said chamber and at second ends with said enclosure and the exterior thereof respectively, said rotatable member passing from the exterior through said bores into said enclosure; and first and second resilient seals in said chamber surrounding said first ends of said bores and portions of said rotatable member in opposing relationship, said inner chamber incorporating an incompressible fluid and confining the same to a substantially fixed volume and provided with a pressure corresponding to the greater of the two pressures defined by the pressure in said enclosure and the exterior pressure, whereby that resilient seal subject to a greater external pressure than internal pressure is held by said fluid in hermetically sealing relationship to said rotatable member.

2. A packing gland for passing a stirring means into an enclosure having a pressure less than the exterior pressure for stirring the contents of said enclosure while maintaining the pressure in said enclosure at its lesser value, including: a housing defining an inlet bore extending from said enclosure at a first end and communicating with the interior of said enclosure at its second end, said stirring means passing through said inlet bore into said enclosure from the exterior and being of smaller diameter than said bore; and a resilient sleeve surrounding the first end of said inlet bore and extending axially along a portion of said stirring means extending from said inlet bore a given distance and thence engaging the periphery of said portion to provide an hermetical seal thereabout, said housing having an inner chamber incorporating an incompressible fluid and confining the same to a substantially fixed volume and provided with a pressure greater than said interior pressure in said enclosure, whereby the interior of said sleeve is subject to the lesser interior pressure in said enclosure and the exterior of said sleeve is subject to the pressure of said fluid to hold said sleeve in hermetically sealed relationship with said stirring means.

3. A packing gland for passing a stirring means into an enclosure having a pressure greater than the exterior pressure for stirring the contents of said enclosure while maintaining the pressure in said enclosure at its greater value, including: a housing defining an inner chamber in pressure communication with said enclosure having an outlet bore communicating with said chamber at a first end and extending from said chamber at its second end, said stirring means passing through said outlet bore into said chamber and said enclosure from the exterior and being of smaller diameter than said bore; and a resilient sleeve surrounding the first end of said outlet bore and extending axially along a portion of said stirring means extending into said chamber a given distance and thence engaging the periphery of said portion to provide an hermetic seal thereabout, said housing having an inner chamber incorporating an incompressible fluid and confining the same to a substantially fixed volume and provided with a pressure at least equal to said interior pressure in said enclosure, whereby the interior of said sleeve is subject to said exterior pressure and the exterior of said sleeve is subject to the pressure of said fluid to hold said sleeve in hermetically sealed relationship with said stirring means.

4. A packing gland for passing a stirring means into an enclosure having a pressure different from the exterior pressure for stirring the contents of said enclosure while maintaining the pressure in said enclosure, comprising, in combination: a housing defining an inner chamber and having inlet and outlet bores passing into said chamber at first ends and communicating with the interior of said enclosure and the exterior thereof at second ends respectively, said stirring means passing through said bores into said enclosure from the exterior and being of smaller diameter than said bores; and first and second resilient sleeves surrounding said first ends of said inlet and outlet bores respectively and extending axially along the portions of said stirring means extending from said bores into said chamber for a given distance and thence engaging the periphery of said portions to provide hermetic seals thereabout; said inner chamber incorporating an incompressible fluid and confining the same to a substantially fixed volume for communicating the pressure to which the interior of said first sleeve is subject to the exterior of said second sleeve when the interior pressure in said enclosure is greater than the exterior pressure; and communicating the pressure to which the interior of said second sleeve is subject to the exterior of said first sleeve when the exterior pressure is greater than the interior pressure in said enclosure.

5. A packing gland according to claim 4, in which said first and second bores are in axial alignment and said stirring means includes an elongated straight rod of circular cross-section adapted to have its exterior end rotated and terminating at its interior end in said enclosure in laterally extending mixing means.

6. A packing gland according to claim 5, in which said incompressible fluid comprises a lubricating oil.

5 References Cited UNITED STATES PATENTS 571,741 11/1896 Bates 277-59 654,882 7/ 1900 Durand et al 277-59 10 2,731,282 1/1956 McManus et al. 277-59 FOREIGN PATENTS 858,483 12/ 1952 Germany. 333,339 8/1930 Great Britain.

1 LAVERNE D. GEIGER, Primary Examiner.

D. MASSENBERG, Assistant Examiner.

Claims

1. A PACKING GLAND FOR PASSING A ROTATABLE MEMBER INTO AN ENCLOSURE HAVING A PRESSURE DIFFERENT FROM THE EXTERIOR PRESSURE COMPRISING: A HOUSING DEFINING AN INNER CHAMBER AND HAVING INLET AND OUTLET BORES COMMUNICATING AT FIRST ENDS WITH SAID CHAMBER AND AT SECOND ENDS WITH SAID ENCLOSURE AND THE EXTERIOR THEREOF RESPECTIVELY, SAID ROTATABLE MEMBER PASSING FROM THE EXTERIOR THROUGH SAID BORES INTO SAID ENCLOSURE; AND FIRST AND SECOND RESILIENT SEALS IN SAID CHAMBER SURROUNDING SAID FIRST ENDS OF SAID BORES AND PORTIONS OF SAID ROTATABLE MEMBER IN OPPOSING RELATIONSHIP, SAID INNER CHAMBER INCORPORTING AN INCOMPRESSIBLE FLUID AND CONFINING THE SAME TO A SUBSTANTIALLY FIXED VOLUME AND PROVIDED WITH A PRESSURE CORRESPONDING TO THE GREATER OF THE TWO PRESSURES DEFINED BY THE PRESSURE IN SAID ENCLOSURE AND THE EXTERIOR PRESSURE, WHEREBY THAT RESILIENT SEAL SUBJECT TO A GREATER EXTERNAL PRESSURE THAN INTERNAL PRESSURE IS HELD BY SAID FLUID IN HERMETICALLY SEALING RELATIONSHIP TO SAID ROTATABLE MEMBER.