US2357416A - Cap - Google Patents

Description

Patented Sept. 5,y 1944 y.

NT vorifice I Charles E.'McManus, SpringLake,l N. J., and Giles B. Cooke, Baltimore, Md., assignors to Crown Cork Seal Company, Inc., Baltimore, Md., a corporation of New York Application July Z5, 1940, Serial No. 347,538

' 1 claim. .(01.215-39) This invention relates to closures of the skirted type having a cushion liner disposed therein.

The cap of the present invention is provided with a protective coating applied by a single operation as by spraying on the surface of the the cap skirt including the raw edge thereof. This continuous facing, when the cap is sealed upon a container, is interposed between the contents and the cushion liner and acts in a manner similar to center spots and overall facings of paper and foil which have heretofore been used. Moreover, the coating on the inner wall of the cap skirt and particularly the raw or free edge thereof not only assures additional rustproofness, buteiiectively closesv any pores or bruised or otherwise uncovered portions in the lacquer surface of the cap.

A particularly important feature of the invention resides in forming the continuous film on the interior exposed surface of an assembled cap.` i. e., shell with liner therein, by a single operation. We have found by spraying a solution 'of protective material into the interior of the assembled cap, that on drying, a thin continuous film is produced coextensive with both the area cushion liner and the adjacent interior wall of of the liner and the entire exposed area of the Caps having the thus is not limited in its application to the details of construction and arrangements of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, vit is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

In the drawing,

Figure 1 is'a sectional view showing a crown cap provided with a protective film in accordance with this invention; and

Figure 2 is a bottom elevation of a. crown cap.

Referring to Figure 1, there `is shown for purposes of illustration a metal crown cap having a top I0 and a depending `crimped skirt II. The invention may be employed with any desired skirted closure, for example, a screw cap, a lug cap, or a pressed-on cap. The cap shell is` customarily coated with a suitable protective lacquer both interiorly and exteriorly, and there is assembled within the shell a cushion liner I2 united thereto by a. suitable adhesive. This cushion liner is composed of various materials such as paper, rubber, natural or composition cork. Cork liners are most generally used.`

'Ihe continuous protective fllm'in accordance with this invention is of a thickness about substantially five ten thousandths to threel thousandths of an inch, and is indicated at .|3. -It constitutes a continuous, adherent facing upon the'exposed surface of the liner I2 and the adjacent interior wall of the cap skirt including its raw or free edge I4. In the case of caps such as crown caps, lug caps and screw caps, or other skirted closures in which the skirt has 'an irregular contour, the film is lcoextensive with and adhered to the entire exposed surface of the interior of the cap. 'I'hat is'to say, in crown caps for example, the film covers the cushion liner and extends integrally therefrom to continuously cover both the hills and valleys of the crimped 'or corrugated area and the raw edge.

As explained above, the .facing layer on the l The protective material employed is one which4 is adherent to metal, the lacquer coating, and the composition liner. It also has the necessary resistant properties so that it will not react with the contents such as beverages and foods and will impart rustproofness and abrasion resistance to the cap shell, particularly at the raw edge of the same. Preferably, dilute solutions of the lm' forming material are employed, e. g., 2 to 10 -percent solutions in a suitable low boiling solvent..

but greater concentrations may be used in some cases, e. g., up to 30% dependent upon the nature of the coating materials. We prefer to use substances such as Vinylite" resin, chlorinated rubber, polyvinyl acetal resin and ethyl cellulose, but

numerous other odorless andv tasteless coating Of particular importance, the illm is applied effectively to assure rapid and inexpensive manufacture by spraying one of the solutions above mentioned upon the interior of the cap. In other words, in a single operation upon the assembled cap, i. e., the cap shell and liner therein, We

are able to produce the continuous facing film of the same material on the liner and on the I adjacent inner wall o! the cap Skirt including its raw edge. We prefer to accomplish the operation by spraying. but satisfactory results may be obtained by-brushing the solution upon the interior of the assembled cap or by dipping the cap in the solution.

After the solution has been applied to the cap, the protective film is deposited from the solution by drying, care being taken to remove all traces of solvent.

In some cases, as where the lm I3 lacks complete continuity between the cushion liner I2 and thev interior Wall surface of the cap, when the cap such as a crown is crimped upon the sealing lip of the container, the adjacent surfaces of the liner and skirt are brought together so that the coating I3 for all practical purposes,

both the sealing liner and the adjacent exposed surface of the cap skirt including the raw edge thereof, and thereby a. continuous coating ia produced which bridges the joint between the sealing linerI and the cap skirt, as shown in Fig. l.

The provision of the illm forming protective materials above described is particularly advantageous' with certain types of cushion liners such as those made of newsboard or paper pulp having the conventional glazed paper facing. These are relatively hard as compared to cork or cork composition, and the 111m being tough. compressible and resilient substantially assists in forming an eiective seal between the cap and the sealing lip of the container.

We claim:

A cap having a top and a skirt, a cushion liner within the cap, and a protective nlm coextensively coated and adhered on the exposed surface of the liner and the entire adjacent interior exposed surface of the cap skirt including the raw edge thereof, the lm on the liner and the film on the skirt being-of the same material and continuous with each other and bridging the Joint between the cushion liner and the cap skirt.

CHARLES E. MCMANUS. GILES B. COOKE.

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