US3025875A - Apparatus for sealing containers - Google Patents

Description

March 20, 1962 H. E. STOVER APPARATUS FOR SEALING CONTAINERS 4 Sheets-Sheet 1 Filed Jan. 22, 1957 IN V EN TOR. M194) 5 6 Tot 4 Trap/v47 H. E. STOVER APPARATUS FOR SEALING CONTAINERS 4 Sheets-Sheet 2 March 20, 1962 Filed Jan. 22, 1957 INVENTOR. Mv/ y 6 6701 64 March 20, 1962 H. E. STOVER 3,025,875

APPARATUS FOR SEALING, CONTAINERS Filed Jan. 22, 1957 4 Sheets-Sheet 3 I 50 i I 8 1 I I 1 49 I 44 T .r-.

INVENTOR. H/m vy Grove-.

March 20, 1962 H. E. STOVER APPARATUS FOR SEALING CONTAINERS 4 Sheets-Sheet 4 Filed Jan. 22, 1957 INVENTOR 44,94 6 5701 5? Array/van,

United States atent 3,925,875 Patented Mar. 20, 1962 fire 3,025,875 APPARATUS FOR SEALING CONTAINERS Harry E. Stover, Lancaster, Ohio, assignor to Anchor Hocking Glass Corporation, Lancaster, Ohio, a corporation of Delaware Filed Jan. 22, 1957, Ser. No. 635,527 3 Claims. (Cl. 137-557) The present invention relates to a method and apparatus for sealing containers and more particularly for delivering gas and vapor to the headspaces thereof in predetermined and adjustable proportions.

The method and apparatus of this invention are particularly adapted for use in sealing containers where a mixture of a gas and a condensable vapor is delivered to the headspace of a container during sealing to provide for a partial vacuum in the headspace and an inert headspace atmosphere.

In a typical container sealing operation, it is often desirable to eliminate a large percentage of the oxygen normally present in the unfilled portions of the containers, usually referred to as the headspace in glass containers and cans, to prevent spoilage of the container contents by oxidization. One presently used method of eliminating the oxygen in the headspace consists in forming a vacuum therein by filling the headspace with a condensable vapor and by thereafter sealing the container and condensing the vapor. Steam is a satisfactory and convenient condensable vapor; however, in many cases steam alone. has proven unsatisfactory as it has been found difficult to control the degree of vacuum created. With too high a vacuum, some packaged products, especially in the baby food industry, have been found to take on a poor appearance resulting from the presence of air bubbles throughout the packaged food resulting from the. expansion of trapped air after the formation of the vacuum in the container headspace. In order to eliminate these air bubbles and other objectionable separation of the packaged foot which gives the appearance of spoilage, a reduction in the degree of vacuum in the container he-adspace has been attempted by leaving a greater percentage of air in the headspace. This increased amount of air in the container headspace, while preventing air bubbles in the prod uct, has resulted in an objectionable oxidation, discoloration, or spoilage of the contents adjacent to the headspace due to its contact with the oxygen in the air remaining in the headspace. It has therefore been found necessary to provide a means of removing a suflicient amount of oxygen from the container headspace while creating a vacuum of predetermined degree substantially lower than customary.

Accordingly, an object of the present invention is to provide an improved method and means for rendering a container headspace inert with respect to the packaged product.

Another object of the present invention is to provide an improved method and means of packaging.

Another object of the present invention is to provide an improved method and means of mixing a gas and vapor in predetermined and adjustable proportions and delivering them to the headspaces of containers.

Another object of the present invention is to provide an easily operated and reliable method of mixing gas and vapor in predetermined proportions during the sealing of containers.

Another object of thepresent invention is to provide a method of delivering exact proportions of a gas and a vapor to the headspaces of containers during sealing.

Another object of the present invention is to provide a relatively simple, eflicient, and easily operated method and apparatus for mixing a condensa'ble vapor and an inert gas readily applicable to sealing machines.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a front elevation view of a preferred embodiment of a mixer in accordance with the present invention;

FIG. 2 is a top plan view of the mixer of FIG. 1;

FIG. 3 is a perspective view of one of the flow control nozzles;

FIG. 4 is an enlarged detailed top plan view in section of the mixer manifold;

FIG. 5 is a fragmentary front elevational view of another embodiment of the mixer with a steam by-pass conduit;

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 5;

FIG. 7 is an elevational view, with parts in section, showing the present invention applied to a turret-type sealing machine;

FIG. 8 is a sectional view taken along lines 88 of FIG. 7; and

FIG. 9 is a sectional view taken along lines 99 of FIG. 8.

The embodiment of the invention illustrated and described below is particularly adapted for use in mixing a condensable vapor and an inert gas and'for delivering the mixture to the headspaces of containers during their sealing. The method and apparatus of the present invention represent an improvement over the sealing machines as disclosed in the inventors copending applications Serial Nos. 370,135, now Patent No. 2,915,862, 397,223, now Patent No. 2,869,301 and 467,081, now Patent No. 2,869,- 300 filed July 24, 1953, December 9, 1953, and November 5, 1954, respectively, in so far as the gas and vapor mixers disclosed therein are concerned.

The preferred embodiment of the invention illustrated at 1 in FIGS. 1 and 2 of the drawings comprises a manifold 2 in Which a first fluid from a first fluid supply means 3 is mixed in predetermined portions with a second fluid from a second fluid supply means 4. The fluid supply means 3 and 4 are adapted as indicated at 5 and 6 (FIG. 2) for connection to suitable sources of gas or vapor. For convenience in describing the preferred embodiment illustrated herein, connector 5 will be described as admititng steam and connector 6 as admitting nitrogen gas. Other gases or vapors may be used as necessary or desirable; for example, carbon dioxide or other inert gases may be used in place of nitrogen where required in a sealing operation and where oxidation is not a troublesome factor air may be used instead of an inert gas. The unit and method give an accurate and uniform degree of vacuum.

The mixing manifold 2 is illustrated in detail in FIG. 4. Manifold 2 comprises a body portion 7 having a suitably tapped steam inlet indicated at 8 for connection to the steam supply 3 and a second suitably tapped gas inlet 9 for coupling to the nitrogen supply 4. The inlets 8 and 9 are connected to a mixing chamber 10 by conduits 11 and 12, so that the steam and gas which enter the manifold 2 through their respective inlets 8 and 9 are conducted to and mixed together in the mixing chamber 10. The mixture of the gas and steamis conducted from mixing chamber 10 to the sealing machine through an outlet 14 in the manifold body 7. One important feature of the preferred embodiment is the supply of steam and gas at equal pressures. Equal pressures not only prevent cross flows, but also give greater uniformity and in effect are the secret of good operation. The invention is not intended to be limited to equal pressures. In addition, the fluids are supplied to the manifold 2 at a predetermined and constant pressure by suitable pressure control means on the fluid supply means 3 and 4 as will be described more fully below.

The relative portions of the two fluids which are mixed together and therefore the composition of the mixture in the mixing chamber 16 of the manifold body 7 is controlled by placing restrictions of a predetermined and calibrated size in the steam and gas conduits 11 and 12, respectively. The preferred embodiment of this restriction comprises hollow plugs 15, one of which is inserted in each of the conduits 11 and 12 to control the rate of flow of the fluids into the mixing chamber 10. As seen in FIG. 4, each of the plugs has a conduit 16 therethrough comprising a radial portion 17 and a connected axial portion 18. At the end of the axial portion 18, a removable nozzle 20 is threadedly connected as indicated at 19. The removable nozzle 20 has a calibrated bore 22 through which the fluid flows into the mixing chamber 10. By selecting a nozzle 20 having a bore of predetermined diameter, the rate of flow of the gas or vapor into the mixing chamber through that nozzle is controlled.

The removable nozzles 20 are gripped at a fiat gripping portion 23 for insertion or removal from the end of the hollow plugs 15. The hollow plugs 15 are inserted into the conduits 11 and 12 of manifold 2 by being screwed into the tapped portion at the outer end of the conduits as indicated at 19. O-rings 24, fitted into suitable annular channels 25, are provided to seal the fluids Within the plug conduits 16. A handle 26 is provided at the end of plugs 15 having suitable slots 27 to provide for the insertion or removal of the plugs 15 by a suitable slot engaging tool. The manifold 2 has a mounting bracket 28 (FIG. 1) for attachment to sealing machines.

In order to supply gas and vapor such as steam and nitrogen to the manifold 2 at constant pressures, each of the supply means 3 and 4 has an automatic pressure regulator 30 and 34, respectively. Each of these regulators has a pressure gauge 31 connected between its output terminal and the fluid inlet on the manifold 2 so that the operator may adjust the output pressures of the pressure regulators 3t) and 34 to predetermined and equal pressures with pressure controls 32 and 36. Each of the fluid supply means 3 and 4, therefore, when connected to a suitable source of gas or vapor, such as steam for supply means 3 and nitrogen gas for supply means 4, supplies the gas or vapor at a predetermined and constant pressure to the appropriate inlet of the manifold 2. As the gas and vapor each reach their respective nozzles 20 in the conduits 11 and 12, their flow through the nozzle 29 will be controlled to the size of the calibrated bore 22 provided in each nozzle and therefore the resulting mixture formed in the mixing chamber of the manifold 2 will be controlled by the relative sizes of the bores 22 provided in the nozzles 20.

The size of the bore 22 for the nozzles 20 is determined by the relative proportions of the two fluids desired in the mixture passing from the manifold outlet 14. The correct nozzle bore sizes for particular sealing conditions are determined by checking the final mixture in the container headspaces under the actual sealing conditions. A number of calibrated nozzles are provided having a graded range of bore sizes. The nozzles are interchanged until the correct combination results. Thus, for example, where the mixer is being used on a sealing machine to form a partial vacuum in a container headspace and it is desired to reduce the headspace pressure to about fifteen inches of mercury and at the same time to eliminate substantially all of the air from the headspace, an initial trial run would be made mixing an inert gas such as nitrogen with steam in approximately equal proportions by using approximately similar nozzle bores. Thereafter. the vacuum actually formed during the run is checked and the proportions of the steam and nitrogen in the mixture are adjusted by inserting calibrated nozzles from suitably graded sets to vary the relative flow of the steam and nitrogen as necessary.

The output pressures of the two pressure regulators are preferably made the same to prevent backflow between the gas and the vapor and also to simplify the operation of the machine.

Where one of the fluids is steam, it has been found preferable with diaphragm-type pressure regulators to invert the regulator 30 as seen in FIG. 1 so that the accumulated moisture from condensed portions of the steam will contact the regulated diaphragm to maintain it in a moistened condition, thereby lengthening its life.

In FIG. 7, the preferred embodiment of the mixer apparatus according to the invention is shown in combination with a sealing machine such as the machine described in US. Patent No. 2,610,779, which is assigned to the assignee of the present invention. The mixer may be used in other sealing machines including those disclosed in the above-listed copending applications. Briefly, the sealing machine shown in FIG. 7 comprises a rotating turret 40 mounted on a vertical shaft 41 and adapted to turn thereon in timed relationship with a series of filled containers 42 which are also being rotated about the shaft 41 on a suitable conveyor 43 under the control of a spacing star wheel 44. A plurality of sealing heads 45 are mounted on the rotating turret 40 in such a position that a hood 46 on the lower end of the sealing head 45 is moved downwardly over each of the containers 42 during a portion of the turrets rotation to admit a fluid mixture to the container headspace and to thereafter force the closure onto the container. A mixer 1 in accordance with the present invention is mounted at the side of the base 47. The output thereof, comprising a mixture of steam and nitrogen issuing from its outlet 14, is conducted to the hollow inner portion of the hood 46 by means of hollow conduit 48, distributor 49, connector pipe 50, and suitable conduits 51 within the sealing hood 46.

Distributor 49, illustrated in FIGS. 8 and 9, is adapted to admit the gas-vapor mixture to the sealing hoods 46 in succession as the turret 40 moves the hoods to the container sealing segment of the turret rotation. A substantial continuous flow of the gas-vapor mixture flows from the mixer 1 to the distributor 49, where it is continuously distributed thereby to the successive hoods 4-6 of the turret sealing heads 45. Distributor 4? comprises a lower ringlike portion 52 which is fixedly attached to the vertical turret shaft 41 and an upper ring 53 which is fixedly attached to the rotating turret 40 for movement therewith. The upper face 54 of the lower ring 52 and the lower face 55 of the upper ring 53 are mounted in abutting and sliding relationship so that they make sliding contact as the turret 4t} revolves about the stationary shaft 41. Conduit 4-8, which conducts the gas-vapor mixture from the mixer 1 to the distributor 49, is connected to an elongated slot 56 in the lower ring 52. Slot 56 communicates with the lower surface 55 of the upper ring 53 so that the gas-vapor mixture passes from slot 56 to apertures 57. One aperture 57 is provided for each sealing hood 46 and is connected therewith by a connector pipe 50. The gas-vapor mixture is admitted to the sealing hoods 4'6 and to the container headspaces during the portion of the turret rotation corresponding to the are described by the elongated slot 56 in the lower ring 52 of the distributor 49.

Where the condensable vapor used in the mixture is supplied at a relatively high temperature, such as, for example, where steam is used, it is desirable to heat the gas portion of the mixture to prevent premature condensation of the condensable vapor in the mixing cavity 10. For this purpose, a suitable heater such as the steam jacket 62 (FIG. 2) is provided on the gas supply means 4. Other types of heaters and other heater locations may be used as necessary.

FIGS. 5 and 6 illustrate another embodiment of the mixer in which a bypass conduit 60 having a control valve 61 therein is provided to by-pass the steam passage through the manifold 2. By-pass 60 allows steam to be applied to the sealing heads or hoods directly Without being mixed with gas where it is desired to warm up the machine prior to a sealing run without wasting nitrogen or where a high vacuum is desired in the sealed containers so that pure steam is used in the sealing operation.

The operation may be summarized as follows. As more fully described above, the correct manifold nozzles 20 having the proper bore sizes to provide a predetermined degree of vacuum and inert gas content in a container headspace are determined in trial runs made with the condensable vapor and the inert gas supplied to the mixer at fixed pressures. Vacuum gauges are available in packing plants for puncturing a sealed closure and registering the headspace vacuum on a gauge. To place the sealing machine in operation, the nozzles 20 determined by the trial runs are inserted in the mixer manifold 2 and the pressure regulators 30 and 34 are set to supply the vapor and the gas to the manifold at the predetermined fixed pressure.

Prior to the admission of the gas-vapor mixture to the sealing machine, the sealing machine is heated to operating temperature by the admission of the unmixed heated vapor or steam directly to the container sealing location by using the mixer manifold by-pass line 60.

Thereafter, the bypass valve 61 is closed and the steam and the gas are admitted to the mixer input connections 5 and 6 so that the mixing action commences in the mixing chamber 10. No further adjustments of the mixer are necessary aside from a periodic checking of the pressure gauges 3-1 and 35 to make sure that the pressure regulators are maintaining the desired pressure since the flow of the gas and the vapor through the calibrated nozzles 20 will automatically provide the desired mixture.

It will be seen that the present invention provides an improved method and apparatus for sealing containers with a predetermined degree of vacuum and inert gas content in the container headspace. The operation is automatic so that it requires a minimum of attention from the sealing machine operator. The adjustment of the sealing machine for different headspace vacuums and headspace gas compositions is easily made and exact duplications of previously used operating conditions are obtainable through the re-insertion of the previously used calibrated nozzles and by the setting of the pressure regulators. The apparatus is rugged and reliable so that it may be depended upon for use over long periods of continuous operation. The vacuum and the inert gas content in the container headspace are regulated with a high degree of accuracy so that the packaged products conform to high standards of appearance and purity even after long periods of storage and so that spoilage and objectionable product discoloration are virtually eliminated.

As various changes may be made in the form, construction and arrangement of the parts herein Without departing from the spirit and scope of the invention and Without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. In a sealing machine the combination of a manifold a mixing chamber in said manifold, a pair of mixing chamber inlets communicating with said mixing chamber and each having a calibrated fluid flow control nozzle positioned therein, a mounting means for each of said nozzles removably connected to said manifold and having an exposed handle portion, a first pressure regulator having its outlet connected to one of said mixing chamber inlets and having its inlet adapted for connection to a source of condensable vapor, a second pressure regulator having its outlet connected to said other mixing chamber inlet and its inlet adapted for connection to a source of gas, a pressure indicator coupled to each pressure regulator outlet and an outlet in said manifold for said mixing chamber.

2. A mixer mechanism for sealing machines comprising the combination of a manifold having a mixing chamber therein, a plurality of separate inlets communicating with said mixing chamber, a fluid flow control nozzle removably mounted in each of said inlets in a holder plug having an exposed gripping means, a plurality of pressure regulators each one having its outlet connected to one of said inlets and having its inlet adapted for connection to a source of fluid, and an outlet in said manifold communicating with said mixing chamber,

3. The mixer mechanism as defined in claim 2 which further comprises pressure indicating means connected between the outlet of each of said pressure regulator means and the mixing chamber inlets.

References Cited in the file of this patent UNITED STATES PATENTS 1,142,355 Mueller June 8, 1915 1,290,513 Collins et al. Jan. 7, 1919 1,764,774 Bloom June 17, 1930 2,270,304 Jacobson Ian. 20, 1942 2,510,568 Fouse June 6, 1950 2,548,938 Booth et al. Apr. 17, 1951 2,759,307 Eolkin Aug. 21, 1956 2,768,487 Day et al. Oct. 30, 1956

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