US 3002648 A
Description (OCR text may contain errors)
Oct. 3, 1961 G. T. RIEKE 3,002,648
EXPLOSION PROOF CONTAINER PLUG Filed March 16, 1959 2 Sheets-Sheet 1 INVENTOR. GLA'IWV. 7'. R/KE.
wiwmz Oct. 3, 1961 G. T. RIEKE EXPLOSION PROOF CONTAINER PLUG 2 Sheets-Sheet 2 Filed March 16, 1959 INVENTOR. 62 czwv 7? R/EKE- 3,002,648 EXPLOSION PROOF CONTAINER PLUG Glenn T. Rieke, Auburn, Ind., assignor to Rieke Metal Products Corporation, Auburn, Ind., a corporation Filed Mar. 16, 1959, Ser. No. 799,812 3 Claims. (Cl. 220-44) This invention relates generally to closures for containers such as cans and drums and more particularly, it relates to a plug closure adapted to relieve internal pressure within containers such as drums, cans and the like.
This application is a continuation-in-part of my application for United States Letters Patent Serial No. 734,536 filed May 12, 195 8 for Explosion Proof Container Plug and assigned to Rieke Metal Products Corporation, Auburn, Indiana, and now abandoned.
In accordance with conventional practice, containers for highly volatile liquids include plug closures which are screwed into a flange in tightly sealing relation thereto in order to prevent leakage of fluids during handling and shipment. Such fluids become highly dangerous when subjected to high temperatures resulting from fires in warehouses and other storage buildings because they volatilize and create excessive pressures within the containers causing them to explode and spread quantities of volatile fluids throughout a fire area. Quite naturally, this results in highly disastrous fires.
The principal object of this invention is to provide a plug closure having valve structure adapted to seal a container under normal conditions and to relieve internal pressure within the container under abnormal temperature conditions.
A further object of this invention is to provide a plug closure having valve structure adapted to seal a container under normal conditions and including a means for venting internal pressure within the container when said valve structure operates to unseal the container.
In accordance with this invention there is provided a plug closure comprising a flanged and threaded member adapted to be screwed into a container and having a centrally disposed pressure release aperture, and a valve operatively associated with said aperture for normally closing it and operative at a predetermined pressure within said container to open said aperture.
The full nature of the invention will be understood from the accompanying drawings and the following description and claims.
FIG. 1 is a top plan view of the plug closure as provided in accordance with this invention.
FIG. 2 is a transverse cross section of the structure illustrated in FIG. 1.
FIG. 3 is a transverse cross section of the modified form of the invention.
FIG. 4 is a cross section taken on line 44 of FIG. 3.
Referring to the drawings, this invention comprises a cupped plug member 10 having a peripheral flange 11 and a threaded portion 12 whereby the plug member 10 may be screwed into what is commonly called the flange of a container such as a drum, can or the like.
Plug member 10 is provided with a pressure relief aperture 14 which communicates with the interior of the container to which the plug member is afiixed. For closing aperture 14 under normal temperature conditions, there is provided a cupped valve 15 and a sealing washer 16 so disposed as to prevent escape of fluid through aperture 14.
Valve 15 is retained in its sealing position by means of a spring retaining member 17 Welded to member 10 or otherwise aflixed thereto at spaced points such as 18 and compressing a coil spring 19 into engagement with valve States Patent 15. Spring 19 may be designed to respond to predetermined pressures within a container of the order of 14 to 18 lbs. per square inch, thereby to permit valve '15 to move out of sealing engagement with member 10. Retainer 17 is provided with an aperture 20 so that gases from within the container may escape through aperture 14 and around the edges of valve 15 and out through the aperture 20. It will be noted that valve 15 has an outer diameter slightly less than the internal diameter of retainer 17, thereby permitting escape of gases. Spring 19 may also be designed to reseal valve member 15 with member 10 at a minimum pressure of the order of 10 lbs. per square inch.
FIGS. 3 and 4 illustrate the modification of this inventionwherein the plug member 10, cupped valve 15 and sealing washer 16 are essentially identical to the corresponding members illustrated in FIGS. 1 and 2. It is found in certain applications of this invention that the sealing washer 16 may expand when the valve 15 moves upwardly under heavy pressure, such expansion being suflicient to seal ofl the venting space between valve 15 and the spring retaining member 17. Thus, the valve 15 is not effective to unseal the container to permit flow of gases through aperture 14, around the edges of valve 15 and out through the aperture 20.
In order to provide venting under relatively high pressures the modification of this invention illustrated in FIGS. 3 and 4 is provided with a spring retaining member 22, the sidewalls of which are formed with spaced rib portions 23, thereby to provide spaced channels 24 at regular intervals around the circumference of member 22.
In operation, the modification shown in FIGS. 3 and 4 functions similarly to that shown in FIGS. 1 and 2 except that even though the sealing Washer 16 may expand into the space between valve 15 and retainer 22, the channels 24 are not sealed ofl by washer 16. Gases from within the container may flow through aperture 14 into the channels 24 and outwardly through the aperture 20 in re tainer 22.
From the foregoing description, it will be apparent that this invention provides a plug closure which renders a container relatively explosion-proof in the sense that rise of external temperature will not cause accumulation of pressure within a container sufficiently high to explode the container and cause dangerous distribution of volatile fluids. It will be obvious to those skilled in the art that the plug closure of this invention may be designed to relieve container pressures at any desired maximum pressures.
The invention claimed is:
1. A pressure relief plug comprising a flanged and threaded plug having a centrally disposed pressure relief aperture, a cup-shaped spring retainer mounted on said plug with its open end facing said aperture and having an escape aperture in its bottom, said retainer having inwardly opening peripheral channels, a cup-shaped valve of smaller diameter than that of said retainer and slidably mounted within said retainer in abutment with the surfaces of said plug surrounding said relief aperture to normally close said relief aperture, and a spring compressed between said retainer and said valve for holding said valve in closed position against predetermined maximum pressure.
2. A pressure relief plug comprising a flanged and threaded plug having a centrally disposed pressure relief aperture, a cup-shaped spring retainer mounted on said plug with its open end facing said aperture and having an escape aperture in its bottom, said retainer having peripheral channels opening inwardly and extending axially of said retainer from the bottom thereof to the mounting on said plug, a cup-shaped valve of smaller 3 diameter than that of said retainer and slidably mounted within said retainer, a sealing washer in abutment with the surfaces of said plug and said retainer surrounding said relief aperture to normally close said relief aperture and said channels, and a spring compressed between said retainer and said valve for holding said valve in closed position against predetermined maximum pressure.
3. A pressure relief plug comprising a plug having a pressure relief aperture, a spring retainer mounted on said plug and facing said aperture, a cup-shaped valve slidably mounted within said retainer, said retainer having peripheral channels opening inwardly toward said valve and extending along the length of travel of said valve, a sealing washer engaging the surfaces of said plug References Cited in the file of this patent UNITED STATES PATENTS 1,441,139 Wichner Jan. 2, 1923 2,538,364 James et a1. Ian. 16, 1951 2,684,780 Friend July 27, 1954 2,781,778 Lisciani Feb. 19. 1957