US2718345A - Apparatus for and a method of filling containers by vacuum - Google Patents

Description

Sept. 20, 1955 S. R. HOWARD APPARATUS FOR AND A METHOD OF FILLING CONTAINERS BY VACUUM Filed Dec. 17, 1952 INVENTOR.

[E1 I Sfan/ey E H ard llnit fitates atent Ofifice APARATUS FOR AND A METHOD OF FILLING CQNTAINERS BY VACUUM Stanley R. Howard, Milton, Mass., assignor to Pneumatte Scale tlorporation, Limited, Quincy, Mass., a corporation of Massachusetts Application December 17, 1952, Serial No. 326,477

13 Claims. (Cl. 22669) This invention relates to vacuum-operated containerfilling apparatus and to a method of filling containers by vacuum.

The invention has for an object to provide novel and improved vacuum filling apparatus for filling containers with finely divided materials wherein provision is .made for introducing an inert gas into the container, preferably prior to and during the filling operation, in a simple and efiicient manner, whereby to reduce to a minimum the air content of the filled container.

A further object of the invention is to provide a novel and improved method of filling containers by vacuum wherein the air remaining in the container after evacuation is replaced by or mixed with an inert gas admitted into the container, preferably prior to and during the filling operation, whereby to produce a filled container substantially devoid of air.

With these general objects in view and such others as may hereinafter appear, the invention consists in the apparatus for and method of filling containers by vacuum and in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings illustrating the preferred embodiment of the invention:

Fig. 1 is a vertical sectional view of the present vacuum filling apparatus;

Fig. 2 is a plan view of the cams, shown in Fig. 1, for controlling the flow of air from the container; and

Fig. 3 is an enlarged detail view of a portion of an air valve shown in Fig. 1.

In general, the present invention contemplates an improvement in vacuum filling apparatus of the type illustrated and described in the United States patent to Carter, No. 2,170,469, wherein a container to be filled is supported in operative relation to a filling head having a suction opening therein connected to a source of vacuum and also with a material-inlet opening connected to a supply of the material, such openings communicating with the interior of the container to effect filling thereof when the air in the container is evacuated. Provision is also made in such prior apparatus for providing a shroud or covering about the container being filled and for maintaining a vacuum within the shroud to prevent collapse of the container during the filling operation.

In practice, some of the food products handled in such apparatus are readily oxidizable upon prolonged exposure to air, and in accordance with the present invention, provision is made for introducing an inert gas, such as carbon dioxide, into the container, preferably prior to and during the filling operation.

In accordance with the present and preferred method of vacuum filling, during each cycle of operation of the apparatus, the air in the container is first partially evacuated, and the remaining air in the container is then substantially diluted by admission of the inert gas. The

leaving an extremely small proportion of air in the container prior to the filling operation whereupon the finely divided material is introduced into the container. In practice, only a partial load may be initially introduced into the container, and thereafter during the remainder of the filling cycle of operation, provision is made for alternately admitting gas and introducing additional increments of material until the container is filled whereby to produce a vacuum filled container substantially devoid of air. One of the last steps in the operation may be introduction of inert gas to produce a gassed and filled container.

Referring now to the drawings, 10 represents a vacuum filling head provided with a depending shroud portion 12 open at its lower end and into which a container 14 supported on a platform 16 may be elevated to present the mouth of the container into airtight sealing engagement with a resilient sealing member 15 carried by the filling head, and to present the platform 16 into airtight sealing engagement with a resilient sealing ring 17 provided at the bottom or open end of the shroud portion 12 thereby assuring airtight seals with the mouth of the container and with the platform 16 during the vacuum filling operation.

The filling head 10 is provided with a material inlet 18 communicating with the interior of the container, the inlet 18 being connected by a pipe 20 to a material-supply hopper 22. The filling head is also provided with a suction opening 24 connected by an air line 26 to a valve or vacuum chamber 28 formed in a valve block 29. The chamber 28 is provided with a suction inlet 30 connected by an air line 32 to a source of vacuum, such as a vacuum pump, indicated diagrammatically at 34.

One wall of the shroud portion 12 is also provided with a suction inlet 36 connected by air line 38 to a second valve or vacuum chamber 40 formed in a valve block 42. The chamber 40 is also provided with a suction inlet 44 connected by an air line 46 to the source of vacuum 34. Thus, it will be seen that in operation, air is evacuated from the interior of the container by air line 26 connected to the valve chamber 28, and the air is simultaneously evacuated from the shroud surrounding the container by air line 38 connected to the second valve chamber 40.

In the operation of the illustrated apparatus, after the container is elevated into sealing engagement with the filling-head and the air in the container is evacuated, provision is made for admitting an inert gas, such as carbon dioxide, into the container, and as herein shown, the chamber 28 is provided with an inlet 48 connected by a pipe 50 to a source of gas, as diagrammatically indicated at 52. Provision is made for closing the suction inlet 30 and opening the inlet 48 to admit gas into the chamber 28, the gas being drawn through the air line 26 and into the container to fill the vacuum therein. Simultaneously therewith, provision is made for closing the suction inlet 44 in the chamber 40 and for opening the chamber 40 and the shroud to the atmosphere through an opening 43 in the wall thereof. Provision is also made in the preferred embodiment of the invention for closing off the material inlet 18 during the initial vacuumizing and gassing operation, as will be described.

As herein illustrated, the suction inlet 30 to the valve chamber 28 is arranged to be automatically opened and closed by a valve 54 formed on the end of a rod 56 which is slidingly mounted in the valve block 29, the outer end of the rod being provided with a cam roll 58 for cooperation with a cam 60 fast on a vertical cam shaft 62. The valve rod' 56 may be spring pressed in a direction to open the suction inlet 30 and to hold the roll against its cam in a manner similar to the lower valve unit 64. arranged to open and close the gas inlet of the gas into the container such as to tamp or settle the finely divided material therein. It will also be observed that the shroud portion around the exterior of the container is likewise subjected to a vacuum and opened to the atmosphere at times corresponding to the vacuumizing and gassing of the interior of the container respectively.

While the preferred embodiment of the invention has been herein illustrated and described, it will be understood that the invention may be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed 1. A vacuum filling apparatus particularly useful for producing containers filled with flowable solid material and which are substantially devoid of air having, in combination, container-supporting means, automatically operating means for evacuating a major portion of the air from within the container, automatically operating means for subsequently introducing an inert gas into the partially evacuated container to thereby efiect the admixture of a large proportion of the inert gas with the smaller and remaining portion of air, automatically operating means for thereafter evacuating the major portion of said gas-air mixture from the container whereby to leave an extremely small amount of air within the container, and means for thereafter causing the flowable solid material to be drawn into the container by the vacuum thus established therein.

2. In a vacuum filling apparatus, in combination, a filling head provided with a material inlet and a suction opening, means for supporting the container in airtight relation to the filling head to establish communication of the material inlet and suction opening with the interior of the container, automatically operating means for successively operatively connecting said suction opening to a source of vacuum and then to a source of inert gas, control means for controlling the gaseous flow from the container and the flow of inert gas into the container, said control means being operated to first partially evacuate the air from within the container, to then subsequently introduce inert gas into the container to form an air-gas mixture composed of a minor portion of air and a major portion of gas, and for thereafter evacuating the major portion of the air-gas mixture from the container whereby to leave an extremely small amount of air within the container, and for effecting the introduction of the material into the container through said material inlet.

3. A vacuum filling apparatus as defined in claim 1 wherein provision is made for deferring the introduction of the flowable solid material into the container until the amount of air in the container has been reduced to a small amount.

4. A vacuum filling apparatus as defined in claim 2 wherein provision is made for deferring the introduction of the flowable solid material into the container until the amount of air in the container has been reduced to a small amount.

5. In a vacuum filling machine for filling containers with finely divided materials, a filling head having a material-inlet opening and a suction opening, both communicating with the interior of the container, means for supporting the container in airtight engagement with said filling head, a material-inlet closure, automatically operating means operatively connecting said suction opening with a source of suction and with a source of inert gas, valve means controlling the flow of said air and gas, and means for automatically actuating said valve means to first create a partial vacuum in the container to remove the major part of the air while said material inlet is closed, for then admitting inert gas into the container to dilute the remaining air, and for then again subjecting the container to vacuum to remove the gas-air mixture prior to opening said closure to admit the material.

6. In a vacuum filling machine for filling containers with finely divided materials, a filling head having a material-inlet opening and a suction opening, both communicating with the interior of the container, means for supporting the container in airtight engagement with said filling head, a material-inlet closure, automatically operating means for operatively connecting said suction opening with a source of suction and with a source of inert gas, valve means controlling the flow of air and gas, means for actuating said valve means to first create a partial vacuum in the container to remove the major part of the air while said material inlet is closed, then to admit inert gas into the container to dilute the remaining air, and to then again subject the container to vacuum to exhaust the gas and air mixture, means for thereafter opening said closure to eifect partial filling of the container, and means for actuating said valve ments to alternately admit gas into the container and create a vacuum therein during the remainder of the operation of filling the container.

7. In a vacuum filling machine for filling containers with finely divided materials, a filling head having a material-inlet opening and a suction opening for communication with the interior of the container, a shroud portion surrounding the exterior of the container provided with a suction opening therein, means for supporting the container in airtight engagement with said filling head and said shroud portion, means for connecting a source of vacuum to said filling head and said shroud, a material-inlet closure, means for connecting a source of inert gas to said filling head, valve means controlling the flow of air and gas to the filling head, means for automatically actuating said valve means to first effect a partial vacuum in the container to remove the major part of the air from the container while said material inlet is closed, then to admit inert gas into the container to dilute the remaining air, and to then again subject the container to vacuum to partially evacuate the gas-air mixture, means for thereafter opening said closure to efiect partial filling of the container, said valve-actuating means being arranged to alternately admit gas into the container and create a partial vacuum therein during the remainder of the operation of filling the container, additional valve means for controlling the flow of air to said shroud, and means for automatically actuating said additional valve means to subject the shroud to a vacuum and to open the shroud to the atmosphere at times corresponding to the vacuumizing and gassing respectively of the interior of the container.

8. In a vacuum filling machine for filling containers with finely divided materials, a filling head having a material-inlet opening and a suction opening for communication with the interior of the container, means for supporting the container in airtight engagement with said filling head, a source of vacuum and a source of inert gas operatively connected with said suction opening, valve means controlling the flow of said air and said gas, and means for automatically actuating said valve means to alternately create a vacuum in the container and admit inert gas therein during the filling operation.

9. The method of filling a container by vacuum which consists in subjecting the interior of a container to a partial vacuum to exhaust a major part of the air therefrom, then admitting an inert gas to dilute the air remaining in the container, then again subjecting the interior of the container to a vacuum to exhaust the gas air mixture, and then introducing finely divided flowable solid material into the container whereby to provide a filled container substantially devoid of air.

10. The method of filling a container with finely divided material by vacuum which consists in placing the mouth of the container in airtight sealing engagement with a filling head, subjecting the interior of the container to a partial vacuum to exhaust the major part of the air therefrom, then admitting an inert gas to dilute

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