US 2046227 A
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Description (OCR text may contain errors)
2 June 30, 1936. w, P] wH TE 2,046,227
CLOSURE CAP FOR JARS Fi led March 26, 1934 Patented June 30, 1936 CLGSE 4 CAP FQR EARS William P. White, enemas... assignor to White Cap Company, @hicago, ill, a corporation of Delaware Application March as, was, Serial No. 71mm i Qlaims; (c1. 2115-43) This invention relates to closures for packing vessels, such as jars and the like, adapted for the packing or packaging of food stufis. It is adapted for use in both domestic and commercial packing or canning.
A general object of the invention is the provi be pointed out or indicated hereinafter, or-will be apparent to one skilled in the artupon an imderstanding oi. the invention or its employmerit in use.
In the drawing forming a part of this specification I show certain forms of closure caps embodying the invention, but it is to be understood that these are presented merely by way of illustration and are not to be construed in any fashion calculated to limit the appended claims short of the true and most comprehensivescope of the invention in the art, inasmuch as the invention may be embodied in numerous other forms differing in various particulars from those here illustrated and hereinafter described.
In said drawing: v
Fig. l is a sectional elevational view of a clo= sure cap in position on the mouth oi a jar-preliminary to the operation for forming the hermetic seal;
Fig. 2 is a similar view showing the relationship of the parts after the hermetic seal has been formed;
Fig. 3 is an elevational view of the closure I cap;
Fig. i is a top View of the same, but including. a modified feature not disclosed in the preceding figures; and
Fig. 5 is an enlarged detail in the nature of a section on approximately line @5 of Fig. l.
The invention will be described as embodied in a cap of the screw type, but it is to be understood that the designation screw cap" as used in the following description andclaims is to include other specific types of caps besides those equipped with screw threads, for example, in various forms 01 caps provided with holdings: attaching lugs, quick threads, or other means for engaging threads, inclines, lugs, or other holdlng devices on the vessel, whereby the cap is attached thereto.
I will now describe the embodiments illustrated in the drawing. The. closure cap comprises a shell which may be drawn from sheet metal or 5 other suitable material having the proper quail ties. Said shell is formed with a-skirt portion it having screw threads it or other means for retentively engaging the vessel and with a resiliently flexible top panel ii, at the upper end 10 of the skirt portion. The top panel is domed upwardly from its line of junction with the slrirt, as seen in Fig. l. The lower margin of the skirt is preferably rolled to form a bead i2. Due to its flexible character, the top panel is adapted to be i flexed downwardly on its line of juncture with the skirt, but its inherent tendency is to return to the upwardly domed position even after flexed inwardly to a concave form.
As seen in Figs. 3 and i, the upper portion oi 20 the skirt is preferably fluted to form salient portions lo alternating with ire-entrant portions it, the top panel conjcining the upper ends oi said portions so that its marginal contour correspends to the form of the fluting. This arrenge- 25 merit augments the inherent tendency of the top a panel to return to its upwardly domed form.
Seated against the under surface oi the top panel is a flat ring gasket it. oi yieldable sealing material. plastic, but at the same time possesses some elastic quality. A suitable gasket may be formed: an unvulvanized or partly vulcanmed rubber composition. Preferably it is adherently in position on the top panel, its location being 35 such that it will be over the mouth rim of contemplated vessel is when the closure cap is properly positioned thereon.
or other suitable means for retentive engagw; :m. by the closure cap. I
in the sealing operation, the closure cap is ap plied to the vessel and, screwed down to an extent such that the gasket i l barely contacts the mouth rim of the vessel so that the parts are in approximately the relationship illustrated in Fig. 1. Then air is withdrawn or displaced from. within the vessel. This may be accomplished by submitting the package to exhaustion in the receiver of an air pump or by heating the vessel so as to expand its air content and force some of it out. The air thus removed from within the msel passes out between the gasket and the mouth rim, as those two parts are not in sealing engsgent After air has thus been displaced from wi '11;
This gasket preferably is somewhat 30 the package, mechanical pressure is applied to the top'panel so as to flex it downwardly. Since the top panel flexes on its line of juncture with the skirt, "the downward flexing of the panel swings the gasket downwardly into flrm sealing engagement with the mouth rim of the vessel. While the top panel is held in this flexed position, wherein the vessel is hermetically sealed, an air pressure difierential is established as between the outer and inner suriaces of the top panel. Ii. removal 01' air from the package has been effected by an air pump in a vacuum machine, the pressure differential is established by admitting atmospheric pressure to the receiver, which pressure will be efl'ective to hold the panel in its downwardly flexed position. If the displacement oi air from the package has been accomplished by a heating of it, the pressuredifierential may be established by the cooling of the pack.- age so that its internal pressure isreduced below atmospheric pressure as a consequence oi. the contraction of contained air and other material or condensation of the contained vapors. Ac-
cordingly, when the pressure differential is established, the external atmospheric pressure on the top panelwill hold it in its depressed position,
approximately as illustrated in Fig. 2 and maintain the gasket hermetically sealed on the mouth rim of the vessel. However, the top panel still retains its elastic tendency to resume its upwardly domed position, even though it has been flexed to a concave form ,as illustrated in Fig. 2.
For removal of theclosure cap, atmospheric "pressure is restored beneath the top panel by admission of air into the package. This may be accomplished by puncturing the top panel. Upon such equalization orthe pressure on the upperand lower surfaces of the top panel, the top panel springs back to its upwardly domed position under the inherent elasticity of the structure. This relieves the compression on the gasket and trees the cap from the binding efiect thereof. Thereupon the closure cap may be readily unscrewed from the vessel.
It will thus be observed that the construction is-one whichfacilitates the removal of screw caps which are'hermetically sealed on vessels from which air has been exhausted. It is airequently encountered circumstance that considerable dii flculty is involved in the removal oi! screw caps from hermetically sealed packing vessel's, even after puncturing oithe cap, due to the friction between the parts resulting from the high compression of the gasket betwen the cap shell-and the vessel. This is particularly true oi commercial packages which have been sealed by ma-- qhinery. This difllculty is obviated by the present construction, since the" closure cap itself automatically relieves the compression of the gasket on the vessel upon the admission 01' air to the package, and permits the closure to be unscrewed quite readily. To prevent the screwing down of the cap too far on the vesseL'the latter may be provided with a peripheral ledge or shoulder li in proper position to act as an abutment.
for the lower margin of the skirt when, the latter has been screwed down to the proper extent.
In Figs. 4 and 5 is illustrated an additional i'eature-which may be employed. In this modification, the central portion of the domed top panel is countersunk as at I 6 and apertured as at H.
-The upper surface oi this countersunk portion forms the seat for avalve II. This valve may be formed or rubber. -It has a stem l8"! which passes through the aperture I! with a clearance In the use of a closin'e cap containing this ieature, the vessel is sealed as above described, the ducts l8and aperture l1 affording passage for air'irom within the package in the exhausting operation. When the flexing pressure is applied to the top panel, the valve I8 is held in seated position, and is held seated by the superior ex- .temal air pressure when the pressure diflferential isestablished. gFor removal of the closure, the valve I8 is lifted, and air admitted to the package through the aperture i'l. This renders it unnecessary to puncture the cap, and consequently the closure may be reused, as for domestic can- What I claim is: 1. A closure cap i'or jars and the like comprising a skirt portion having engaging elements for 4 retentively engaging cooperating elements on the jar to retain the closure against removal axially therefrom, an upwardly domed top panel conjoining the upper skirt portion, and a gasket re-,
tained in contact with the under surface of the top panel adjacent the skirt portion, said top panel being resiliently flexible downwardly from its margin whereby to swing the gasket downwardly, and retaining its elastic tendency to return to its upwardly domed position after being flexed to a concave position.
2. A closure cap for Jars and the like as specifled in claim 1 and wherein the upper part of the skirt portion is fluted and the top panel is of scalloped peripheral contour. Y
3. A closure cap for jars and the like as specifled in claim 1 and wherein the ,top panel is integral at its margin with the top oi. the skirt portion and theupperpart oi the skirt portion is fluted to form alternately associated salient and ,re-entrant portions.
4. A closure capi'or jars and the like comprising an annular screw-threaded skirt portion, an elastically flexible upwardly domed top panel con.-
, joining the skirt portion and a gasket oi yieldable sealing material in contact with the under surface of the top panel adjacent the skirt portion. said top panel being flexible downwardly from its margin to swing the gasket. downwardly and its inherent elasticity being eifective to return itto an upwardly domedposition after it has been flexed to aconcave position.
5. A closure cap for jars and the like as specifled in claim 4 and wherein the gasket is ently secured to the top panel.
6.A closure cap for jars and the like as specifled in claim 4 and wherein the plastic quality. I
7. A closure cap ior jars and the like as specifled in claim 4 and wherein the gasket is of elastic quality.
adher- Basket is 01 8. A closure im- Jars and the like as specifled in claim-4 and wherein the top panel is propanel is countersunk and a valve is arranged to seat in said countersunk portion under pressure applied to the upper surface of the top panel to flex it downwardly.
' 10. A packing container comprising in combination a vessel having a mouth rim, and a closure cap for hermetically sealing the mouth of the vessel, said closure cap having a skirt portion and an upwardly domed resiliently flexible top panel conjoining the upper part of said skirt portion and a gasket of sealing material seated against the top panel adjacent the skirt portion. said vessel and skirt portion having elements engageable to retain the closure cap against remove! from the vessel in the axial direction and to support the closure cap with the gasket above and out of sealing engagement with the mouth rim, said top panel being flexible downwardly to place it under resilient tension and to depress the gasket into sealing engagement with the mouth rim. g
, 11. A. packingcontainer comprising in combination a screw-threaded closure cap having an upwardly domed resiliently flexible top panel and a sealing gasket resting in contact with a portion ofsaid upwardly domed panel so as to be movable downwardly by downward flexing thereof, and a vessel having a screw thread engageable with the cap to support the same with the gasket out, of sealing cooperation with the vessel but in position to be pressed into sealing cooperation with the vessel by downward flexion of the top panel.
' WILLIAM P. WHITE.