US2004964A - Method of making container seals - Google Patents

Description

J1me 1935- R. s. WESTGATE ETAL 2,004,964

METHOD OF MAKING CONTAINER SEALS Original Filed Jan. 11, 1928 Harry (3.65am

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Patented June 1a, 1935 UNITED STATES PATENT OFFICE 2,004,965 METHOD or MAKING con'mmna SEALS York Application January 11, 1928, Serial No. 246,008

Renewed September 29, 1933 Claims. (Cl. 113-121) 5 as to be readily pierceable by an ordinary knife for making the contents instantly available.

In the packaging of gases'or highly volatile liquids in sheet metal containers for transportation, storage, sale, and'use under a considerable range of thermal conditions, it is of the utmost importance to minimize leakage at the closure and consequent contamination, waste, and danger of explosion. Sealing by means of solder has been the commonest method of accomplishing an airtight closure, but this method has been attended by numerous disadvantages: among others, the appreciable cost of solder; the necessity of performing the work by hand; the hazard of applying the hot soldering iron in the presence of the highly inflammable gas or vapors; the difficulty of assuring the absolute covering of the joint. a v

In an effort to avoid these disadvantages it has been proposed to effect the seal mechanically, dispensing with the solder; but closures of this type that haveheretofore appeared have been of such construction as to be unable to withstand, for example, the heat of the tropics and other rigorous conditions, and do not perform satisfactorily even in ordinary circumstances imthe temperate zone.

It is an object of this invention to provide a mechanical seal that shall be free from the defects of the soldered closure and shall furthermore be inexpensive and virtually hermetic, so as to be proof against all adverse climatic and other unfavorable conditions, with a liberal factor of safety.

In the practice of our invention there is placed on the neck of a sheet metal container a soft metal cap of such marginal conformation as to fit the upper interior of the neck and having a depending flange. A flanged hard metal ring, of. similar conformation, is then superimposed upon the cap. A stationary mandrel is now set upon the ring within the neck, and revolving rollers, caused to converge by the application of centripetal force upon their axes, are applied to the ring flange and, by rapidly spinning thereagainst at constantly increasing speed, gradually tighten it against the exterior of the neck, the interposed soft metal serving as a packing and forming an impervious joint. Access may thereafter be had to the contents of the container by puncturing the center of the soft metal cap with any sharp or pointed implement, for example, a knife or a pin, or by cutting the soft metal along the inner periphery of the hard metal ring. In contemplation of the latter procedure a suitably dimensioned inward offset is provided in the neck for seating a stopper to protect. the unused portion of the contents.

The understanding of the objects, advantages, and practice of the invention will be facilitated by reference to the following specification and accompanying drawing in which Figure 1 is a plan view of the closure cap;.

Figure 2 is a plan View of the closure ring;

Figure 3 is an elevation, partly in section, of a container with the cap and the ring on its neck and of the spinning apparatus in idle position;

Figure 4 is a similar view showing the closure sealed and the spinning apparatus in operative position;

Figure 5 is an enlarged sectional view of a fragment of the sealed closure;

Figure 6 is an elevation showing in section a sealed closure from which the central portion of the cap has been removed, with a stopper inserted and seated in the offset; and

-Figure 7 is an elevation showing in section a modification of the sealed closure.

In the drawing I0 designates a container, preferably of sheet metal, provided with a neck ll, preferably taper, having a shoulder I2 and a taper central offset l3. A stamped cap l4 formed of a soft metal such as lead and comprising a central circular portion l5, which may be domed if desired; an annular portion I6 so inclined upwardly as to fit the interior of neck II, and a depending flange H, is set upon the neck I l. A ring 18 formed of a hard metal such as tin plate and having a general conformation similar to that of cap I4 except that it is centrally apertured, giving a circular inner periphery l9, and having a flange 20, is now mounted upon the cap l4.

Then the container is placed under a spinning apparatus (not a part of this invention) including a stationary mandrel with a head 21 conforming in shape with the interior of ring l8 and a shank 22 surrounded by a rotatable hollow shaft 23 provided at its lower extremity with a flange 24. The latter has a plurality of regularly spaced slots 25 (only one of which is shown), each receiving a taper arm 26 the bottom of which carries a rotable roller 21 having a conical surface 28 and held in place by This spinning apparatus is lowered until the stationary mandrel 2| is seated in ring l8. By suitable means shaft 23 is now set in rotation. The centrifugal force thereby exerted upon the distal ends of arms 26 gives rise to a corresponding centripetal force at the proximal ends thereof, bringing conical surfaces 28 into firm contact with flange 20. The speed of rotation is then steadily increased and causes a constantly increasing pressure by surfaces 28 against flange By virtue of this accelerated rotation of shaft 23, the revolving and rotating rollers 2! spin the flange at every point of its surface tight against neck II, the interposed soft metal flange l1 serving as a packing throughout its 7 area. A virtually hermetic seal is thus obtained.

Instead of they embodiment above illustrated and described, forms may be constructed according to the same principle wherein a seal is provided interiorly of the neck or both exteriorly and interiorly thereof. For example, by rollers similarly operated with and against the interior of ring l8, or by other suitable means, the interior of ring It may be spun against the interior of neck H, the interposed annular portion l6 forming a wide, impervious seal.

To make the contents accessible it is necessary merely to puncture portion IS with a sharp or pointed implement. It is generally found, however, that all the contents are not exhausted simultaneously, and it becomes desirable to safeguard the residue. Offset I3 is provided for this purpose; so that when portion 15 has been removed by cutting along periphery I9 with a knife, for example, and part of the contents poured out, a suitable stopper 3|, which maybe an ordinary cork, is inserted into the offset l3,

which is of such shape as to seat the stopper -not required, andthe modification shown in Figure 7 maybe employed.

Containers formed with the closure herein described remain impervious at the seal even though subjected-to conditions'far more rigorous than those encountered in transportation, storage, and use in various climates. For example, if filled with ether and immersed for fifteen minutes in water maintained at a temperature of 135 F., not more than about five per cent of the cans so sealed develop any leakage. This provides a large factor of safety. whereby the probability of leakage in ordinary circumstances is reduced practically to zero.

Various changes may be made in the method of sealing containers and in the form, construction and arrangement of parts of the container without departing from the invention or sacrificing any of the advantages thereof.

' We claim:

1. Themethod of mechanically sealing a sheet-metal container to adapt it to hold ether secure against escape, and of simultaneously providing the container with a readily pierce- .able closure, which comprises successively superposing upon the neck of the container a softmetal cap and a hard-metal ring, each having a depending flange, and, by means of revolving 'and rotating rollers pressing against substantially the entire width of the ring flange, gradually spinning the flanges. concomitantly towards the neck until they are closely juxtaposed thereto, thereby tightly confining the entire circumference and substantially the entire width of the cap flange between the ring flange and the neck and thus providing a vapor-impervious packing, the neck of the container retaining substantially its initial form and size.

2. The method of mechanically sealing a sheet-metal container to adapt it to hold ether secure against escape, and of simultaneously providing the container with a readily pierceable closure, which comprises successively superposing upon the neck of the container a soft-metal cap and a hard-metal ring, each having a depending flange, and, by means of revolving and rotating rollers pressing against the ring flange, spinning the flanges towards the neck until they are closely juxtaposed thereto, thereby tightly confining the cap flange between the ring flange and the neck and thus providing a vapor-impervious packing.

-3. The method of mechanically sealing a sheet-metal container to adapt it to hold ether secure against escape, and of simultaneously providing the container with a readily pierceable closure, which comprises successively superposing upon the neck of the container a softmetal cap and a hard-metal ring, each having a depending flange, and, by means of revolving and rotating rollers pressing against the ring flange, spinning the flanges towards the neck until they are closely juxtaposed thereto, thereby tightly confining the entire circumference and substantially the entire width of the cap flange between-the ring flange and the neck and thus providing a vapor-impervious packing.

4. The method of mechanically sealing a sheet-metal container to adapt it to hold ether secure against escape, and of simultaneously providing the container with a readily pierceable closure, which comprises successively superposing upon the neck of the container a softmetal cap and a hard-metal ring, each having a depending flange, and spinning the flanges towards the neck until they are closely juxtaposed thereto, thereby tightly confining the cap flange between the ring flange and the neck and thus providing a vapor-impervious packing,'the neck of the container retaining substantially'its initial form and size.

5. The method of mechanically sealing a sheet-metal container and of simultaneously providing it with a-readily pierceable closure,-

RALPH S. WESTGATE. HARRY C. A. BEHR.

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