US2263691A - Method of vacuumizing containers - Google Patents

Description

' Nov. 25, 1941.

E; M. EYNKUR ,691

METHOD OF VACUUMIZING CONTAINERS Filed June 4, 1938 Patented Nov. 1941 I METHOD OF VACUUMIZING CONTAINERS Edward M. Enkur, Baltimore, Md assignor to Crown Cork & Seal Company, Inc., Baltimore, Md., a corporation or New York Application June 4, 1938, Serial No. 211,8'15

4 Claims.

The present invention relates to a method for vacuumizing containers.

In vacuumizing containers, it has heretofore been the practice to use either a vacuum chamber and associated pump, or to obtain a vacuum by filling the head space of the container with steam, seal the container and then rely upon the condensation of the steam to establish a vacuum. The first mentioned system requires rather. expensive apparatus, and the secondsystem, involving steam condensation, is not altogether satisfactory as usually practiced because moisture is frequently left in the head space of the container-after condensation has occurred. With many products, particularly food products, such moisture is extremely undesirable.

An important object of the present invention is to provide a method and apparatus for vacuumizing containers by expanding the air or other gas within the container head space so that a portion of such gas will be forced out of the container head space, leaving a vacuum condition when the remaining gas condenses or contracts to a normal state.

Another object of the invention is to provide an apparatus and method whereby the presence of moisture in the container after vacuumization will be entirely prevented.

.A still further object of theinvention is to provide a vacuumizing apparatus and method which I isextremely simple but which nevertheless eliminates all of the principal difliculties of previous apparatus and-methods. I

Other objects and advantages of the invention will be apparent from the following specification and drawing.

The drawing is a side elevation, partly in vertical longitudinal section, of a machine embodying my apparatus invention.

The embodiment of the invention illustrated in the drawing involves the application of heat to a container top after the top has been loosely applied to a filled container. Such heating of the top causes the air within the headspace of the container to be expanded so that a portion of such air is driven from the head space. The

top is then sealed to the container with the revsuit that when the air within the head space is subsequently cooled and thereby condensedler contracted to its normal state, there will be a vacuum condition within the head space.

In the drawing, the jars or other containers to be vacuumized are indicated at J, the container caps being designated by the letter C. The containers J are delivered to the infeed'end of an endless container supporting conveyor 5 by any suitable means, the containers having been filled to a suitable height before delivery to conveyor 5. A cap delivery chute 6 of usual construction is provided above the infeed end of the conveyor 5, suitable means being provided at the lower end] of the chute so that the passage of a container J beneath the lower end of the chute will cause a cap to be removed and dropped to a loosely seated position upon the container mouth.

A steam chamber 8 extends over the central portion of the upper run of the supporting conveyor 5, this chamber having an opening 9 of such width and height that it will permit the entrance of containers positioned upon the conveyor. Chamber 8 is kept filled with steam issuing from jets ina steam line In, the pressure of the steam in the line merely being sufllcient to insure that the atmospherewithin the chamber 8 is heated and thereby expanded. Chamber 8 may be heated for the same purpose by means other than free steam, for example, by means of closed steam coils or electric heaters.

In the embodiment of the apparatus shown in the drawing, s cap heating element I I consisting of an endless metallink chain or belt isv provided within the steam chamber 8, element II movin about spaced pulleys, driven in any suitable manner. The belt or chain is of such width that it will bear upon the entire surface of a cap and thus heat the full area of the latter. In order to heat the element H, a steam header I2 is provided having jets facing the upper surface of the upperrun of element ll,but it will be understood that this heating element may be an electhe heater, or that a gas flame maybe used. A pressure-member or shoe I3 is positioned above the lower run of the element II to force this run downwardly, the pressure member being urged downwardly by resilient means, for example, a

spring, not shown. The lower run of element II is preferably inclined slightly downwardly toward its outfeed end, or at least to the right hand portion of the pressure member 13, thereby insuring, that a cap C, while still loosely positioned on a container mouth wlll move for some distance with element l I with the upper surface or portion of the cap in contact with the underside of the lower 7 run of element II and that the cap will not be forced to fully seated or sealed position upon the container until it has been adequately heated. as hereinafter described, by the heating element H. r

A cap cooling element ll of endless form is also provided over the upper run ofvthe supporting conveyor 5, the left hand or infeed end of this element extending into'an outlet opening l5 of the steam chamber 8. Element I4 is supported upon pulleys or sprockets in a manner similar to the element II and is driven by any suitable means. The element It is also of suiflcient width to have contact with the entire area of the top walls of the caps. A pressure member leis mounted above the lower run of the element 14 to hold the run downwardly, springs, not shown, preferably being provided to maintain the member I 8 and the lower run of element I l downwardly. The lower run of element It and pressure member l6 are so arranged with respect to supporting conveyor 5 that a. container cap 0 will be forced, to or held in fully seated or sealed position upon a container J from a moment shortly after contacting with element I4, and will be held in such sealed position until it reaches the outfeed end of element M. It is to be emphasized that a cap must be in fully seated and sealed position upon a container from a time prior to reaching the lowermost portion of this element. that the only expulsion of air or other gas from the head space of the container will occur prior the egress of the cap and container from chamber 8, until the cap has been cooled sufllcientlv to obtain the condensing or contracting action hereinafter referred to.

In order to obtain a cooling element ll, a spray of cooling water is directed from a water line I! upon the upper surface of the pressure member or shoe l6, and also upon the lower run of the endless element ll to keep the same cooled over its portion extriorly' of the steam chamber 8. obvious that means other than a be used for the necessary cooling.

In the carrying out of the method by the apparatus illustrated in the; drawing, when a cap C, loosely seated upon the mouth of a container J, is moved beneath the heating element II, the cap, at least, will be quickly heated to such a degree that the air or other gas within the interior of the cap, that is, within the head space of the container, as well as the atmosphere inimediately adjacent the cap and upper portion of the container, will be expanded to the desired degree.

Continuing its movement with the elements I5 and II, the container will-come beneath the lowermost portion of thebottom run of element I l and the cap Cwill be forced to fully seated or sealed position on the container. container leaves element II and moves to the position indicated at J, that is, a position between'the outlet end of the cap heating element It will be water line may ll and the inlet end of the cap cooling element ll if the internal pressure resulting from the expansion of air or other gas in thehead space of the container is so high as to prevent the cap from remainingln completelysealed position' upon the container, the cap will be slightly quick cooling of a cap by When the lifted by such pressure, and the surplus pressure will be expelled from the head space. This snifting action will, of course, leave the top space of the container filled with highly heated and -expanded air or other gas. The presence of.

steam or other rarefied or expanded atmosphere in chamber 8, that is, at a point surrounding the upper portion of the container, will prevent air at atmospheric pressure from flowing into the head space of the container during or just after venting.

In some instances, the air at normal temperature or normal pressure originally within the head space of the container may be expanded to to the movement of the cap to sealed position by the element II, or at least simultaneously with the movement of the cap to such position. In these instances, the cap will remain in sealed position upon the container during the remainder of the movement of the container beneath the element ll, during its movement between elements II and I 4, and also during movement beneath the cap cooling element ll. Thus, in such instances, the element I will function as a sealing element as well as a heating element.

In any event, it Will be understood from the above that the point of expulsion of surplus expanded air or gas from the container head space can be controlled as desired by regulating the degree of heat applied to the top wall of the container, and that shifting, e. g., the expulsion of surplus expanded air, will occur whenever the air or gas in the head space of the container has been expanded to such an extent as to overcome the pressure existing outside of the con- W stood'that as a vacuum condition is being established within the head space, the cap will be drawn to a sealed position.

Obviously, when a container snifts at point J, that is, a point between elements If and I4, element l4 serves as a sealing element as well as a hold-down or cooling element. The infeed end of the element I4 is positioned within the steam chamber 8 so that if a cap has lifted by shifting action adjacent point J, it will again be moved to sealed position with respect to its container by the element It before passing out into the atmosphere through the exit opening l5 of chamber 8. Thus, the entire portion of the path of travel of a container during which shifting may occur is surrounded by an expanded or rarefied or steam atmosphere, as by the steam chamber 8, and the element I4 is so positioned with re- .spect to the chamber and also the container supporting conveyor 5 that cap 0 will be in securely seated and sealed position upon a. container'at the time that it leaves the steam chamber 8 beneath the cooling element I4.

The positioning of the cooling means I! above the lower run of the element l4 will insure that the fabric or flat metal links or other cap contacting members of whichthe element may be formed will be cooled immediately after leaving "the steam chamber 8, and that the temperature of the lower run of the element will be progressively reduced by the cooling spray or other cooling means as it moves away from the steam chamber outlet l5. Also, the cap holding and cooling element It will have its lower run of such length-that all air or og er gas within the head such; a degree by heating element II, and before 76 space of a container J will be condensed or contracted before the container moves from beneath the right hand or outlet end of element I4.

number of well-known types.

If steam, as fron. the line it, is used to provide a heated or otherwise expanded or rarefied atmosphere within the chamber 8, the free steam within the chamber will only provide suflicient pressure to prevent entrance of air into the chamber through the chamber openings 9 and I5. Hence "no steam will move into the head space of a container and the presence otfree moisture within the head space of a container sealed by thepres'ent method and apparatus will in the container head space gives highly satisfactory results, and if conditions are so regulated that snifti g 'will occur prior to sealing the cap by the heating element l I, the invention may be practiced with a cap of the type whereinretaining means, alone, is relied uponttornaintain the material having reasonably high heat conductivity, though in some instances themethod may be practiced by heating a portion ofthe container body, andin such case, heat conductivity of the container material may be reliedluponf The phraseology used in the specification is for the purpose of description and is notintended to limit the invention, the scope of the invention being indicated in the claims.v

I claim: v y

1. A method of vacuumizing a filled container comprising applying a dry cap loosely to the con tainer, moving the container and applied cap into a steam chamber, immediately applying loleast a portion of the head space air will be quickly expelled, the local heating being continued during movement through the steam atmosphere to prevent access of steam to the head space,'and sealing the cap upon the container;

2. A method of vacuumizing a filled container comprising applying a drycap loosely to the conthan exist inythe surrounding" rarefied atmos cap seated and sealed, Thecaps must be of a phereso that at least apart of the head space tainer, moving the container and applied cap into a rarefied atmosphere,applyinglocal dry heat to the cap to create higher (pressure and temperature conditions within the headspace than exist in the surrounding rarefiedatmosphere so that at least a part of the head space gas will be expelled into the surrounding rarefied atmos: phere, and sealing the cap upon the container. 3. A method of vacuumizing a filled container comprising applying a dry cap loosely to the container, moving the container andappliedcap 1 into a rarefied atmosphere applying local dry heat to the cap to create higher pressure and temperature conditions within the head space gas -will be expelled into the'surroundingrarefied atmosphere, and then sealing the cap upon the container and cooling thehead space.

4. Agmethod of vacuumizingafill'ed container comprisingapplying a dry cap loosely to the container, moving the container and applied cap into a heated chamber, applying sufficient local dry heat to the cap to heat the head space to a temperature above that of the product within the container and ab'ovethe temperature of the chamber so that the pressure within the head space will be increased and at least a portion of the head space gas will be expelled, and sealing the cap upon the container.

cal dry heat to the cap toexpand the head space air before it can become moist and so that at EDWARD

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