US20140196405A1

US20140196405A1 - Vacuum Sealer with a Retractable Heater Bar

Info

Publication number: US20140196405A1
Application number: US14/155,136
Authority: US
Inventors: David Owens; Elif Caputa
Original assignee: Sunbeam Products Inc
Current assignee: Sunbeam Products Inc
Priority date: 2013-01-14
Filing date: 2014-01-14
Publication date: 2014-07-17

Abstract

Systems (200) and methods (1300) for selectively retracting a first component of a Vacuum Packaging Appliance (“VPA”). The method comprises: causing the first component to normally be in an engaged position in which the component facilitates a formation of a heat seal along an open end of a container disposed within the VPA; detecting an existence of at least one first condition associated with the VPA; and applying a magnetic field in proximity to the component when the first condition is detected, whereby the first component is at least maintained in an unengaged position in which the first component no longer facilitates the formation of the heat seal.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional Patent Application No. 61/752,050 filed on Jan. 14, 2013.

BACKGROUND OF THE INVENTION

1. Statement of the Technical Field
The inventive arrangements relate to vacuum packaging and sealing appliances. More particularly, the invention concerns vacuum packaging and sealing appliances employing electromagnets for transitioning heat sealing bars between engaged positions in which heat seals are formed and unengaged positions in which no heat seals are formed,
2. Description of the Related Art
Various appliances are used for vacuum packaging purposes to protect perishables and other products against oxidation. Such appliances typically use a heat scaling element to form a seal at an open end of a container. The heat sealing element can include two adjacent heat sealing bars between which the open end of the container is placed. Prior to formation of the heat seal, the container may be evacuated of excess moisture and air through the use of at least one vacuum pump. The evacuation of moisture and air from the container minimizes the spoiling effects of oxygen on perishables and other products.
Despite the advantages of these appliances, they suffer from certain drawbacks. For example, such appliances may be used in repetitive vacuum and heat sealing operations, such as in hunting applications in which a relatively large amount of game needs to be stored in containers within a short a period of time. During such repetitive vacuum and heat sealing operations, these conventional appliances do not meet the performance requirements since pre-seals are formed on the containers before a sufficient amount of fluid is evacuated therefrom. The pre-seals are created by the heat sealing strip(s) which do not have a sufficient amount of time to cool down prior to a next iteration of the vacuum and sealing operations.

SUMMARY OF THE INVENTION

The present invention concerns apparatus and methods for selectively retracting a first component of a Vacuum Packaging Appliance (“VPA”). The methods comprise causing the first component to normally be in an engaged position in which the first component facilitates a formation of a heat seal along an open end of a container disposed within the VPA. The first component can include, but is not limited to, a support structure for a heat sealing strip configured to apply heat to the open end of the container during heat sealing operations of the VPA or a bumper configured to apply pressure to the open end of the container during heat sealing operations of the VPA. In some scenarios, the first component is biased into the engaged position using at least one resilient member (e.g., a spring) disposed within a base of the VPA.
Thereafter, an existence of at least one first condition associated with the VPA is detected. In some scenarios, the first condition comprises, but is not limited to, at least one of the following: a locking of a lid in a closed position; an expiration of a predefined period of time; a start of a particular iteration of vacuum and sealing operations performed by the VPA; an excessive temperature of a heat sealing element; an excess of fluid in the container or a vacuum Chamber of the VPA; and an excess of liquid in a drip tray of the VPA.
When the first condition is detected, a magnetic field is applied in proximity to the component. The magnetic field can be generated through a supply of current to at least one electro-magnet disposed within a base or a pivoting lid of the VPA. As a result the application of the magnetic field, the first component is at least maintained in an unengaged position in which the first component no longer facilitates the formation of the heat seal.
In some scenarios, the first component is formed of a ferrous material or has a ferrous material coupled thereto such that the magnetic field causes the first component to be transitioned from the engaged position to the unengaged position. Additionally or alternatively, the resilient member is normally in an uncompressed state and the magnetic field causes the resilient member to transition from the uncompressed state to a compressed state. In other scenarios, the first component is moved into range of the magnetic field using a mechanical retraction structure, mechanical retraction structure can be manually actuated by depressing a lever of a latch mechanism configured to look a lid of the VPA in a closed position.
The application of the magnetic field can be terminated when the first condition no longer exists or a second condition is detected. The second condition can include, but is not limited to, at least one of the following: an unlocking of the lid from its closed position; expiration of a pre-defined period of time; a completion of a particular iteration of vacuum operations performed by the VPA; a start of a particular iteration of heat sealing operations performed by the VPA; a reduction of a temperature of a heat sealing element to at least a first threshold level; a reduction in a fluid pressure level within the container or a vacuum chamber of the VPA to at least a second threshold level; and a reduction of a liquid level in a drip tray of the VPA to at least a third threshold level.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be described with reference to the following drawing figures, in which like numerals represent like items throughout the figures, and in which:

FIG. 1 is a schematic illustration of an exemplary container that is useful for understanding the present invention.

FIG. 2 is a perspective view of an exemplary VPA that is useful for understanding the present invention,

FIG. 3 is a perspective view of the exemplary VPA of FIG. 2 with a lid in an open position.

FIG. 4 is a top view of the VPA of FIGS. 2-3 with the lid removed and a portion of a base cutaway.

FIG. 5 is a cross-section of the VPA of FIGS. 2-4.

FIG. 6 is a rear view of the VPA of FIGS. 2-5,

FIGS. 7-8 collectively provide schematic illustrations of a first exemplary architecture for a retractable component of a sealing mechanism of a VPA.

FIGS. 9-10 collectively provide schematic illustrations of a second exemplary architecture for a retractable component of a sealing mechanism of a VPA.

FIGS. 11-12 collectively provide schematic illustrations of a third exemplary architecture for a retractable component of a sealing mechanism of a VPA.

FIG. 13 is a flow diagram of an exemplary method for selectively retracting a first component of a VPA.

DETAILED DESCRIPTION

It will be readily understood that the components of the embodiments as generally described herein and illustrated in the appended figures could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the figures, is not intended to limit the scope of the present disclosure, but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects as illustrative. The scope of the invention is, therefore, indicated by the appended claims. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussions of the features and advantages, and similar language, throughout the specification may, but do not necessarily, refer to the same embodiment.
Furthermore, the described features, advantages and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
Reference throughout this specification to “one embodiment”, “an embodiment”, or similar language means that a particular feature, structure, or Characteristic described in connection with the indicated embodiment is included in at least one embodiment of the present invention. Thus, the phrases “in one embodiment”, “in an embodiment”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
As used in this document, the singular form “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. As used in this document, the term “comprising” means “including, but not limited to”.
The present invention generally concerns systems and methods for selectively retracting a first component of a Vacuum Packaging Appliance (“VPA”), such as a heat sealing strip or a bumper. The methods generally involve: causing the first component to normally be in an engaged position in which the component facilitates a formation of a heat seal along an open end of a container disposed within the VPA; detecting an existence of at least one first condition associated with the VPA; and applying a magnetic field in proximity to the component when the first condition is detected. As a result of the magnetic field, the first component is at least maintained in an unengaged position in which the first component no longer facilitates the formation of the heat seal.
Notably, the present invention overcomes various drawbacks of conventional VPAs. For example, VPAs may be used in repetitive vacuum and heat sealing operations, such as in hunting applications in which a relatively large amount of game needs to be stored in containers within a short a period of time. During such repetitive vacuum and heat sealing operations, conventional VPAs do not meet the performance requirements since pre-seals are formed on the containers before a sufficient amount of fluid is evacuated therefrom. The pre-seals are created by the heat sealing strip(s) which do not have a sufficient amount of time to cool down prior to a next iteration of the VPA vacuum and sealing operations. As such, the pre-seals occur before a vacuum pump has a sufficient amount of time to remove all of the air in the container.
Notably, the retractable first component(s) of the present invention eliminate the formation of such pre-seals. As such, the VPAs of the present invention have an improved overall performance as compared to that of conventional VPAs. Generally, the first component(s) of the present invention are retracted from an engaged position in which a heat seal can be Rimed along an open end of a container to an unengaged position in which said heat seal cannot be formed. This retraction prevents a heat sealing strip(s) from pre-sealing the container when it is still too hot from the previous heat sealing operation. The manner in which the first component(s) is(are) retracted will become evident as the discussion progresses. Notably, the first component(s) need(s) only be retracted by a relatively small distance (e.g., <0.5 inches) in order to prevent pre-sealing of a container.
Embodiments will now be described with respect to FIGS. 1-13. Embodiments generally relate to VPAs configured to seal perishables or other products within a container. An example container 100 comprising at least one seal formed along an edge thereof is provided in FIG. 1. The container can include, but is not limited to, a plastic bag 102 with one or more seals 104, 106, 108, 110 formed on edges thereof. At least one of the seals 110 is formed by a VPA. If less than all of the seals are formed by the VPA, then the remaining seals may have been pre-formed at a factory. In all cases, perishables 112 or other products may be disposed in the container 100 for protection against oxidation.
An exemplary architecture 200 for a. VPA is provided in FIGS. 2-6. VPA 200 is generally configured to evacuate and seal a container (e.g., container 100 of FIG. 1). VPA 200 may also be configured to dispense a material that can be used to form the container. In this case, VPA 200 comprises a base 210 with a storage compartment 302 formed therein. The storage compartment 302 is provided for at least partially housing a roll 304 of flexible container material. In some scenarios, the flexible container material comprises a multi-layer plastic material with at least two edges having pre-formed seals therealong (e.g., seals 106 and 108 of FIG. 1). The roll 304 may be stored in the storage compartment 302 with or without any support mechanisms. In both cases, the roll 304 is free to at least rotate within compartment 302.
A pivoting lid 202 is hingedly coupled to the base 210 of the VPA 200. In this regard, the pivoting lid 202 can be transitioned between a closed position shown in FIG. 2 and an open position shown in FIG. 3. A user may manually cause such a transition using a lip 212 formed on an exterior front edge of the lid 202. The lip 212 allows the user to easily grasp and pivot the lid 202 about its pivot point for transitioning the lid to and from its closed position or its open position. The pivot point is defined by the hinge(s) not shown) pivotally coupling a rear bottom edge 314 of the lid 202 to the base 210.
The lid 202 may be locked into the closed position via a latch mechanism 316, 318, 320. The latch mechanism comprises a depressible lever 316 and two hooks 318, 320 configured to engage latch cams (not shown) disposed in the base 210. In this regard, the latch cams are accessible to the hooks 318, 320 via apertures 322, 342 formed in the base 210. Notably, the hooks 318, 320 are sized and shaped to pass through respective apertures 322, 342 when the lid 202 is pivoted in the direction of arrow 324 into the closed position. The lever 316 allows a user to cause the hooks 318, 320 to lockingly engage the latch cams so that the lid 202 is locked into its closed position. The hooks can be disengaged, from the latch cams automatically by the VPA 200 or manually by the user via the lever 316. In the manual scenario, the lever locks the latch mechanism when moved in a downward direction and unlocks the latch mechanism when moved in an upward direction.
When the pivoting lid 202 is in its closed position, it encloses the roll 304 within the storage compartment 302, as shown in FIG. 2. The pivoting lid 202 also allows a section of container material to be dispensed from the storage compartment 302 when it is in its open position, as shown in FIG. 3. Once at least a portion of the container material is dispensed from the storage compartment 302, the pivoting lid 202 can be returned to its locked closed position.
Thereafter, the section of container material is cut from the roll 304. The cutting is achieved using a cutting device 204 integrated within the VPA 200. Such cutting device arrangements are well known in the art, and therefore will not be described in detail herein. Still, it should be understood that the cutting device 204 is moveably disposed within a track 206 formed in the pivoting lid 202 of the VPA 200. Any container material disposed below the cutting device 204 can be cut simply by sliding the cutting device 204 back and forth (or right and left) as shown by arrow 208 within the track 206.
Notably, the cutting device 204 is provided as a separate and distinct component from any VPA element configured to facilitate the formation of a heat seal. In this regard, the present invention overcomes various drawbacks of conventional VPAs in which the cutting device is integrated or combined with a heating element. For example, pre-seals can be formed in such conventional VPA systems when the cutting devices are used to cut container material from rolls and the heating element is still hot from a previous iteration of VPA operations.
Next, the cut section of container material is used to form a partially sealed container into which perishables or other products (e.g., items 112 of FIG. 1) can be disposed. In this regard, the VPA 200 is used to form a seal (e.g., seal 104 of FIG. 1) in an open end of the cut section of container material.
The seal is formed using a sealing mechanism of the VPA 200. The sealing mechanism comprises a bumper 334 and at least one heat sealing strip 336, 338. At least one of the components 334-338 of the sealing mechanism is retractable for various reasons, as will be described below. Still, at this time it should be understood that the bumper 334 is disposed on the pivoting lid 202 and the heat sealing strip 336, 338 is disposed on the base 210 of the VPA 200. Embodiments of the present invention are not limited in this regard. For example, the bumper 334 can alternatively be disposed on/in the base, while the heat sealing strip 336, 338 is disposed on/in the pivoting lid 202. In all cases, the bumper 334 and heat sealing strip 336, 338 are arranged to mate against each other when the lid 202 is in its closed position and a heat seal is to be formed. In effect, the open end of the container material can be sandwiched between elements 334, 336, 338 of the sealing mechanism. Thereafter, heat can be applied to the open end of the container material via the heat sealing strip 336, 338 so as to form a heat seal (e.g., seal 104 of FIG. 1) thereon.
After the perishables or other products have been disposed within the partially sealed container, the remaining open end of the partially sealed container is placed within the VPA 200. Next, the lid 202 is once again transitioned into its locked closed position. Thereafter, vacuum operations are performed by the VPA 200 to evacuate excess moisture and air from the interior of the partially sealed container. The evacuation of excess moisture and air is achieved using at least one vacuum pump 340 and a sealed vacuum chamber. The evacuation of moisture and air from the container minimizes the spoiling effects of oxygen on perishables and other products. Once a predetermined pressure is reached in the vacuum chamber as measured by a pressure sensor 506, a seal (e.g., seal 110 of FIG. 1) is formed along the remaining open end of the partially sealed container inserted into the VPA 200, whereby a hermetically sealed container is provided which retains the freshness of the contents thereof.
The sealed vacuum chamber is formed by elements of the base 210 and lid 202. More specifically, the base 210 comprises a lower vacuum trough 306 and a gasket 308. Similarly, the pivoting lid 202 comprises an upper vacuum trough 310 and a gasket 312. The troughs 306, 310 and gaskets 308, 312 are arranged to be respectively vertically and horizontally aligned with each other when the lid 202 is in its closed position so as to form a composite sealed vacuum chamber.
A Vacuum Motor Assembly (“VMA”) 340 is disposed in the base 210 behind the lower vacuum trough 306 for providing evacuating suction within the sealed vacuum chamber. Once a predetermined pressure is reached in the vacuum chamber as measured by a pressure sensor 506, current can be applied to the heat sealing strip(s) 336, 338 for heating the same to a specified temperature (e.g., 160° C. to 200° C.). Notably, in some scenarios, the vacuum operations are not completed until some specified time after formation of the seal. This ensures that any additional food or moisture between the two film layers between the newly formed seal and respective open end of the container are removed.
The forgoing vacuum and sealing operations are controlled by the user through use of a control panel 326. In some scenarios, the control panel 326 is only operative when the lid 202 is in its locked closed position. The control panel 326 is disposed on the base 210 so as to be directly adjacent to the lid 202 when it is in the closed position, as shown in FIG. 2. The control panel 326 comprises electronic control circuitry 504. The electronic control circuitry 504 may be at least partially disposed on a circuit board 328. The circuit board 328 is located directly beneath the user interface 330 of tae control panel 326.
The electronic control circuitry 504 is electrically connected to the VMA 340, sealing mechanism 334-338, and/or power circuit of the VPA 200. Operations of some or all of these components 332-340 are controlled by the electronic control circuitry 504. In this regard, the electronic control circuitry 504 can include, but is not limited to, a microprocessor 502, a system bus, a memory, a system interface and/or other hardware/software elements. The memory can comprise volatile memory and non-volatile memory. Various types of information can be stored in the memory. Such information includes, but is not limited to, processing results, control programs, parameter values, and/or measurement values.
The other hardware elements may comprise, but are not limited to, temperature sensors 424, 426. The temperature sensors 424, 426 are disposed adjacent to or in proximity to the heat sealing strip(s) 336, 338, respectively. In some scenarios, the temperature sensors 424, 426 are located at various locations along the entire length of the heat sealing strip 336, 338. In other scenarios, the temperature sensors can alternatively or additionally be disposed on the length of the bumper 334.
The temperature sensors 424, 426 are provided to continuously or periodically measure the temperature of the heat sealing strip(s) 336, 338. Such temperature detection can be used to ensure that the proper sealing temperature is being applied along the entire width of the container during the heat sealing process, as well as other purposes as described below. In this regard, measurement values output from the temperature sensors 424, 426 are communicated to the electronic control circuitry 504 for further processing. For example, the microprocessor 502 may be configured to determine a mean average temperature of the heat sealing strip(s) 336, 338 and adjust current output thereto accordingly. Current can be applied to the heat sealing strip(s) 336, 338 for a predetermined period of time such that the temperature thereof is sufficient for forming a seal on an open end of a container.
The other hardware elements may also comprise a liquid level sensor 510. The liquid level sensor 510 is configured to detect an amount of accumulated liquid in a drip tray 350 of the VPA 200. The drip tray 350 rests in the lower vacuum trough 306 during operation of the VPA 200 for collecting excess liquids evacuated from the container (e.g., container 100 of FIG. 1). The drip tray 350 can be removed from the lower vacuum trough 306 so that the evacuated liquid can be discarded. The liquid level sensor 510 facilitates a determination by the electronic control circuitry 504 as to when the excess liquid should be removed. In this regard, the output of the liquid level sensor 510 is communicated to the electronic control circuitry 504 for further processing. This processing involves analyzing the output of the liquid level sensor 510 to detect when the liquid in the drip tray 350 exceeds a particular threshold level. When this condition exists, the electronic control circuitry 504 may perform operations to temporarily disable the VMA 340 and heat sealing elements 336, 338, as well as indicate to the user that the excess liquid should be removed from the drip tray 350. Once the excess liquid is removed, the VMA 340 and heat sealing elements 336, 338 are once again enabled.
The user interface 330 can include, but is not limited to, switches 402-406, Light Emitting Diodes (“LEDs”) 408-422, and/or a display screen (not shown). One or more of the switches can be a power switch configured to enable the turning on and/or off of the VPA 200. When the power switch is in its “turned on” position, power is supplied to the electronic control circuitry 504 from a power circuit of the VPA 200 (e.g., transformer 332 and/or a battery). The power circuit can include an internal power source (e.g., a battery) or a plug 508 for connecting the VPA 200 to an external power source (e.g., a wall mount socket).
One or more of the switches 402-406 can be configured to enable a user to control the heat sealing operations. The same or different switch 402-406 can be configured to control the vacuum operations. For example, in some scenarios, it may be desirable to commence only the heat sealing operations for sealing an open end of the container material after being cut and prior to being filled with perishables or other products. Additionally, it may be desirable to commence: the vacuum operations once the perishables or other products have been inserted into the partially sealed container; and the heat sealing operations subsequent to the evacuation of at least some fluid from the interior of the container during the vacuum operations. One or more of the LEDs 408-422 or other indicia of the control panel 326 can be used to indicate to the user when the heat sealing operations and/or the vacuum operations are being performed and/or have been completed. For example, an LED may emit red light when the heat sealing operations are being performed. Once the heat sealing operations are completed, the LED can cease emitting light.
As noted above, the heat sealing operations are achieved using the sealing mechanism of the VPA 200. The sealing mechanism comprises one or more retractable components. In some scenarios, only one of the bumper 334 and heat scaling strip(s) 336, 338 is retractable. In other scenarios, both the bumper 334 and heat sealing strip(s) 336, 338 are retractable. Retraction of the component(s) 334-338 can be initiated manually by the user via the depressible lever 316 of the latch mechanism or automatically via the electronic control circuitry 504 based on the existence of at least one condition. For example, an automatic retraction of component(s) 334-338 can be performed when: a pre-defined period of time expires; a particular iteration of the vacuum and sealing operations of the VPA are to begin; the temperature of the heat sealing element exceeds a particular threshold value during a given period of time; the pressure of the vacuum chamber is not at a particular level; and/or a certain amount of liquid is detected in a drip tray 350 of the VPA. When the particular condition no longer exists, the component(s) 334-338 can be returned to its(their) engaged position(s). This will become more evident as the discussion progresses.
Referring now to FIGS. 7-12, there are provided schematic illustrations that are useful for understanding various architectures facilitating the retraction of the component(s) 334-338. Prior to discussing these schematic illustrations, it should be understood that the VIA 200 overcomes various drawbacks of conventional VPAs. For example, VPAs may be used in repetitive vacuum and heat sealing operations, such as in hunting applications in which a relatively large amount of game needs to be stored in containers (e.g., container 100 of FIG. 1) within a short a period of time. During such repetitive vacuum and heat sealing operations, conventional VPAs do not meet the performance requirements since pre-seals are formed on the containers before a sufficient amount of fluid is evacuated therefrom. The pre-seals are created by the heat sealing strip(s) 336, 338 which do not have a sufficient amount of time to cool down prior to a next iteration of the VPA vacuum and sealing operations.
Notably, the retractable component(s) 334-338 of the present invention eliminate the formation of such pre-seals. As such, the VPA 200 has an improved overall performance as compared to that of conventional VPAs. Generally, the component(s) 334-338 of the present invention are retracted from an engaged position in which a heat seal can be formed along an open end of a container to an unengaged position in which said heat seal cannot be formed. This retraction prevents a heat sealing strip 336, 338 from pre-sealing the container when it is still too hot from the previous heat sealing operation. The manner in which the component(s) 334-338 is(are) retracted will become evident as the discussion progresses. Notably, components 334-338 needs only be retracted by a relatively small distance (e.g., <0.5 inches) in order to prevent pre-sealing of a container.
Referring now to FIGS. 7-8, there are provided schematic illustrations of a first exemplary architecture for a retractable component 700 of a sealing mechanism of a VPA (e.g., VPA 200 of FIG. 2). The retractable component 700 is shown as comprising a heat element. However, the present invention is not limited in this regard. Alternatively, the retractable component 700 may include a bumper (e.g., bumper 334 of FIG. 3). In either case, at least a portion of the retractable component 700 can be disposed in the base 706 (e.g., base 210 of FIG. 2) of the VPA.
The retractable component 700 comprises a heat sealing strip 702 (e.g., heat sealing strip 336 or 338 of FIG. 3) and a support structure 704 mechanically supporting the heat sealing strip. In some scenarios, the support structure 704 comprises a rigid member and a dielectric material. The rigid member can be configured to act as a heat sink and have any suitable shape, such as a bar shape or a planar shape. The dielectric material is disposed between the rigid member and the heat sealing strip 702.
The heat sealing strip 702 is biased to an engaged position via the support structure 704 and at least one resilient member 712, 714, 716. The resilient member 712, 714, 716 can comprise, but is not limited to, a spring which is normally in its uncompressed state. In the engaged position, the heat sealing strip can cause a heat seal (e.g., seal 104, 106, 108 or 110 of FIG. 1) to be formed on a container (e.g., container 100 of FIG. 1).
As shown in FIG. 8, the heat sealing strip 702 can be retracted from the engaged position to an unengaged position. In the unengaged position, the heat sealing strip cannot cause a seal to be formed on a container. The retraction of the heat sealing strip 702 can be achieved using the support structure 704, at least one optional mechanic al retraction structure 718, 720 and/or at least one electro- magnet 802, 804.
If the mechanical retraction structures 718, 720 are not employed, then the electro- magnets 802, 804 cause the support structure 704 to move in the direction of arrow 800 when current is applied thereto. In effect, the heat sealing strip 702 is transitioned from its engaged position shown in FIG. 7 to its unengaged position shown in FIG. 8. Electro-magnets are well known in the art, and therefore will not be described herein. Still, it should be understood that current can be applied to the electro- magnets 802, 804 for applying a magnetic field to the support structure 704. In some scenarios, the support structure is formed of a ferrous material, and therefore can magnetically interact with the electro- magnets 802, 804. In other scenarios, the support structure is formed of a non-ferrous material. In this case, a magnetic material (not shown) can be coupled to the support structure for magnetically interacting With the electro-magnet. When current is no longer applied to the electro- magnets 802, 804, the heat sealing strip 702 returns to its engaged position shown in FIG. 7.
The current can be applied to the electro- magnets 802, 804 by the electronic control circuitry (e.g., electronic control circuitry 504 of FIG. 5) of the VPA upon the detection of the existence of a particular condition. For example, current can be applied to the electro- magnets 802, 804 when: a pre-defined period of time expires; the Nth iteration of the vacuum and sealing operations of a VPA are to begin; the temperature of the heat sealing element 702 exceeds a particular threshold value during a given period of time; the pressure of a vacuum chamber is not at a particular level; and/or a level of liquid in a drip tray is above a threshold level.
If the mechanical retraction structures 718, 720 are employed, then the mechanical retraction structures 718, 720 move the support structure 704 into and/or out of range of the magnetic field created by the electro- magnets 802, 804. Accordingly, in some scenarios, each mechanical retraction structure 718, 720 comprises at least one component 722 which is movable in the two directions shown by arrow 724. As shown in FIGS. 7-8, the component 722 resides above the support structure 704. Embodiments of the present invention are not limited in this regard. For example, the component 722 may additionally or alternatively reside below the support structure 704. In these cases, a person skilled in the art would readily appreciate that the following discussion can be amended accordingly.
When moved in the downward direction, component 722 applies a downward pushing force on the support structure 704 so as to move it into range of the magnetic field. In effect, the support structure magnetically interacts with the electro-magnet, thereby causing the resilient members 712-716 to be retained in their compressed state and the heat sealing strip 702 to be retained in its unengaged position. In contrast, when current is no longer supplied to the electro- magnets 802, 804 and/or the component 722 is moved in the upward direction, the resilient members 714-716 bias the support structure in an upwards direction. More particularly, the resilient members 712-716 return to their uncompressed states. Consequently, the heat sealing strip 702 is returned to its engaged position shown in FIG.
In some scenarios, component 722 can be manually caused to move downward by actuation of the depressible lever (e.g., lever 316 of FIG. 3) of the VPA, latch mechanism described above. When this occurs, the heat sealing strip 702 is retracted below the top surface of a base of the VPA, so as to prevent a container from contacting the heat sealing strip 702 until a particular condition exists. As noted above, the electro- magnets 802, 804 are used to maintain the heat sealing strip 702 in its retracted or unengaged position. Once the particular condition is detected, the application of current to the electro- magnets 802, 804 can be ceased. For example, such current application can be terminated when: a pre-defined period of time expires; the temperature of heat sealing strip falls below a threshold value; the pressure of a vacuum chamber reaches a particular level; and/or a level of liquid in a drip tray falls below a threshold level. In effect, the support structure 704 no longer magnetically interacts with the electro- magnets 802, 804, and therefore is once again biased to its engaged position shown in FIG. 7 by the resilient members 712-716.
Additionally or alternatively, component 722 can be automatically caused to move downward upon the detection of the existence of a particular condition (e.g., the expiration of a pre-defined period of time, the temperature of the heat sealing element exceeds a particular threshold value during a given period of time, the pressure of the vacuum chamber is not at a particular level, and/or a level of liquid in a drip tray is above a threshold level). When or prior to when the particular condition no longer exists, the component 722 can be automatically caused to return to its original position(s).
Referring now to FIGS. 9-10, there are provided schematic illustrations of a second exemplary architecture for a retractable component 900 of a sealing mechanism of a VPA (e.g., VPA 200 of FIG. 2). The retractable component 900 is shown as comprising a heat element. However, the present invention is not limited in this regard. Alternatively, the retractable component 900 may include a bumper (e.g., bumper 334 of FIG. 3). In either case, at least a portion of the retractable component 900 can be disposed in the base 906 (e.g., base 210 of FIG. 2) of the VPA.
The retractable component 900 comprises a heat sealing strip 902 (e.g., heat sealing strip 336 or 338 of FIG. 3) and a support structure 904 (e.g., a bar) mechanically supporting the heat sealing strip. In some scenarios, the support structure 904 comprises a rigid member and a dielectric material. The rigid member can be configured to act as a heat sink and have any suitable shape, such as a bar shape or a planar shape. The dielectric material is disposed between the rigid member and the heat sealing strip 902.
The heat sealing strip 902 is biased to an engaged position via the support structure 904 and at least one resilient member 912, 914, 916. The resilient member 912, 914, 916 can comprise, but is not limited to, a spring which is normally in its uncompressed state. In the engaged position, the heat sealing strip can cause a heat seal (e.g., seal 104, 106, 108 or 110 of FIG. 1) to be formed on a container (e.g., container 100 of FIG. 1).
As shown in FIG. 10, the heat sealing strip 902 can be retracted from the engaged position to an unengaged position. In the unengaged position, the heat sealing strip cannot cause a seal to be formed on a container. The retraction of the heat sealing strip 902 can be achieved using the support structure 904, at least one resilient member 912-916, and at least one electro- magnet 1002, 1004, 1006.
During operation, the electro- magnets 1002, 1004, 1006 cause the resilient members 912-916 to compress in the direction of arrow 1000 when current is applied thereto. In this regard, it should be understood that current can be applied to the electro- magnets 802, 804 by the electronic control circuitry (e.g., electronic control circuitry 504 of FIG. 5) of the VPA upon the detection of the existence of a particular condition. For example, current can be applied to the electro- magnets 802, 804 when: a pre-defined period of time expires; the temperature of the heat sealing element 902 exceeds a particular threshold value during a given period of time; the pressure of a vacuum chamber is not at a particular level; and/or a level of liquid in a drip tray is above a threshold level.
Notably, the resilient members 912-916 are formed of a ferrous material. Thus, when current is applied to the electro-magnets 1002-1006, a magnetic field is applied to the resilient members 912-916. In effect, the resilient members 912-916 magnetically interact with the electro-magnets 1002-1006, whereby the resilient members 912-916 are caused to transition from their uncompressed states shown in FIG. 9 to their compressed states shown in FIG. 10. In turn, gravity causes the support structure 904 to travel in the downwards direction, as shown by arrow 1000. Consequently, the heat sealing strip 902 is transitioned from its engaged position shown in FIG. 9 to its unengaged position shown in FIG. 10.
When current is no longer applied to the electro-magnets 1002-1006, the resilient members 912-916 return to their uncompressed states shown in FIG. 9. As a result, the resilient members 912-916 apply an upwards pushing force on the support structure 904, whereby the support structure 904 is caused to travel in the upwards direction. As a result, the heat sealing strip 902 is returned to its engaged position shown in FIG. 9. The resilient members 912-916 and support structure 904 maintain the heat sealing strip 902 in its engaged position until current is once again applied to the electro-magnets 1002-1006.
The application of current to the electro-magnets 1002-1006 can be ceased when certain conditions are detected. For example, such current application can be terminated when: a pre-defined period of time expires; the temperature of heat sealing strip falls below a threshold value; the pressure of a vacuum chamber reaches a particular level; and/or a level of liquid in a drip tray fails below a threshold level.
Referring now to FIGS. 11-12, there are provided schematic illustrations of a third exemplary architecture for a retractable component 1100 of a sealing mechanism of a VPA (e.g., VPA 200 of FIG. 2). The retractable component 1100 is shown as comprising a bumper 1102 (e.g., bumper 334 of FIG. 3). However, the present invention is not limited in this regard. Alternatively, the retractable component 1100 may include a heat element (e.g., heat element 702/704 of FIG. 7 or 902/904 of FIG. 9). In either case, at least a portion of the retractable component 1100 can be disposed in the lid 1106 (e.g., pivoting lid 202 of FIG. 2) of the VPA.
In some cases, the bumper 1102 is formed of a non-ferrous material, such as rubber. As such, a magnetic material 1104 may be disposed on a surface thereof. The magnetic material 1104 is provided to facilitate the magnetic interaction between the bumper 1102 and at least one electro-magnet 1202-1206.
During operation, the bumper 1102 normally resides in its engaged position shown in FIG. 11. In the engaged position, the bumper 1102 applies pressure on an open end of a container which is disposed therebelow. This pressure facilitates the formation of an adequate heat seal along the open end of the container by a heat element disposed in a base of a VPA.
Notably, the bumper 1102 can be retracted from the engaged position shown in FIG. 11 to an unengaged position shown in FIG. 12. In the unengaged position, the bumper 1102 does not facilitate the formation of any heat seal along an open end of the container. The retraction of the bumper 1102 can be achieved using the magnetic material 1104 and/or at least one electro-magnet 1202-1206.
In this regard, the electro-magnets 1202-1206 cause the magnetic material 1104 to move in the direction of arrow 1208 when current is applied thereto. In effect, the bumper 1102 is transitioned from its engaged position shown in FIG. 11 to its unengaged position shown in FIG. 12. Electro-magnets are well known in the art, and therefore will not be described herein. Still, it should be understood that current can be applied to the electro-magnets 1202-1206 for applying a magnetic field to the magnetic material 1104. The current can be applied to the electro-magnets 1202-1206 by the electronic control circuitry (e.g., electronic control circuitry 504 of FIG. 5) of the VPA upon the detection of the existence of a particular condition. For example, current can be applied to the electro-magnets 1202-1206 when: a pre-defined period of time expires; the Nth iteration of vacuum and sealing operations are to be performed by a VPA; the temperature of a heat sealing element exceeds a particular threshold value during a given period of time; the pressure of a vacuum chamber is not at a particular level; and/or a level of liquid in a drip tray is above a threshold level.
Once the particular condition is detected, the application of current to the electro-magnets 1202-1206 can be ceased. For example, such current application can be terminated when: a pre-defined period of time expires; the temperature of heat sealing strip fails below a threshold value; the pressure of a vacuum chamber reaches a particular level; and/or a level of liquid in a drip tray falls below a threshold level. In effect, the magnetic material 1104 no longer magnetically interacts with the electro-magnets 1202-1206, and therefore the bumper 1102 and magnetic material 1104 fall in a downward direction as a result of gravitational forces applied thereto. Consequently, the bumper 1102 is returned to its engaged position shown in FIG. 11.
Referring now to FIG. 13, there is provided a flow diagram of an exemplary method 1300 for selectively retracting a first component of a VPA (e.g., VPA 200 of FIG. 2). The method 1300 begins with step 1302 and continues with step 1304. In step 1304, the first component is caused to normally be in an engaged position in which the first component facilitates a formation of a heat seal (e.g., seal 104, 106, 108, or 110 of FIG. 1) along an open end of a container (e.g., container 100 of FIG. 1) disposed within the WA. The first component can include, but is not limited to, a support structure (e.g., support structure 704 of FIG. 7 or 904 of FIG. 9) for a heat sealing strip (e.g., heat sealing strip 336, 338 of FIG. 3, 702 of FIG. 7, or 802 of FIG. 8) configured to apply heat to the open end of the container during heat sealing operations of the VPA or a bumper (e.g., bumper 334 of FIG. 3 or 1102 of FIG. 11) configured to apply pressure to the open end of the container during heat sealing operations of the VPA. In some scenarios, the first component is biased into the engaged position using at least one resilient member (e.g., resilient member 712, 714, 716 of FIG. 7 or 912, 914, 916 of FIG. 9) disposed within a base of the VPA.
Thereafter, step 1306 is performed in which an existence of at least one first condition associated with the VPA is detected. In some scenarios, the first condition comprises, but is not limited to, at least one of the following: expiration of a pre-defined period of time; a start of a particular iteration of vacuum and sealing operations performed by the VPA; an excessive temperature of a heat sealing element e.g., heat sealing strip 336, 338 of FIG. 3, 702 of FIG. 7, or 802 of FIG. 8); an excess of fluid in the container or a vacuum chamber of the VPA vacuum chamber 306-312 of FIG. 3); and an excess of liquid in a drip tray of the VPA (e.g., drip tray 350 of FIG. 3).
When the first condition is detected, a magnetic field is applied in proximity to the first component, as shown by step 1308. The magnetic field can be generated through a supply of current to at least one electro-magnet (e.g., electro- magnet 802, 804 of FIG. 8, 1002-1106 of FIG. 10, and/or 1202-1206 of FIG. 12) disposed within a base (e.g., base 210 of FIG. 2) or a pivoting lid (e.g., lid 202 of FIG. 2) of the VPA. As a result the application of the magnetic field, the first component is at least maintained in an unengaged position in which the first component no longer facilitates the formation of the heat seal.
In some scenarios, the first component is formed of a ferrous material or has a ferrous material coupled thereto such that the magnetic field causes the first component to be transitioned from the engaged position to the unengaged position. Additionally or alternatively, the resilient member is normally in an uncompressed state and the magnetic field causes the resilient member to transition from the uncompressed state to a compressed state. In other scenarios, the first component is moved into range of the magnetic field using a mechanical retraction structure as shown by steps 1310 and 1312. The mechanical retraction structure can be manually actuated by depressing a lever of a latch mechanism configured to lock a lid of the VPA in a closed position.
The application of the magnetic field can be terminated when the first condition no longer exists or a second condition is detected, as shown by step 1314. The second condition can include, but is not limited to, at least one of the following: expiration of a pre-defined period of time; a completion of a particular iteration of vacuum operations performed by the VPA; a start of a particular iteration of heat sealing operations performed by the VPA; a reduction of a temperature of a heat sealing element to at least a first threshold level; a reduction in a fluid pressure level within the container or a vacuum chamber of the VPA to at least a second threshold level; and a reduction of a liquid level in a drip tray of the VPA to at least a third threshold level. Upon completing step 1314, step 1316 is performed where method 1300 ends or other processing is performed.
As noted above, the present invention uses a novel approach to at least maintaining heat sealing strips or other components facilitating the formation of a heat seal in their unengaged positions. The novel approach involves employing electro-magnets. The electro-magnets provide a simpler, less complex, and less costly technique for raising and lowering such heat sealing components as compared to other conventional techniques (e.g., such as those that employ expandable air bladders, pneumatic cylinders and/or hydraulic cylinders).
Although the invention has been illustrated and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Thus, the breadth and scope of the present invention should not be limited by any of the above described embodiments. Rather, the scope of the invention should be defined accordance with the following claims and their equivalents.

Claims

We claim:

1. A method for selectively retracting a first component of a Vacuum Packaging Appliance (“VPA”), comprising:

causing the first component to normally be in an engaged position in which the first component facilitates a formation of a heat seal along an open end of a container disposed within the VPA;

detecting an existence of at least one first condition associated with the VPA; and

applying a magnetic field in proximity to the first component when the first condition is detected, whereby the first component is at least maintained in an unengaged position in which the first component no longer facilitates the formation of the heat seal.

2. The method according to claim 1, wherein the magnetic field is generated through a supply of current to at least one electro-magnet disposed within a base or a pivoting lid of the VPA.

3. The method according to claim 1, wherein the first component is formed of a ferrous material or has a ferrous material coupled thereto such that the magnetic field causes the first component to be transitioned from the engaged position to the unengaged position.

4. The method according to claim 1, wherein the first component comprises a support structure for a heat sealing strip configured to apply heat to the open end of the container during heat sealing operations of the VPA or a bumper configured to apply pressure to the open end of the container during heat sealing operations of the VPA.

5. The method according to claim 1, further comprising biasing the first component into the engaged position using at least one resilient member disposed within a base of the VPA.

6. The method according to claim 5, wherein the resilient member is a spring normally in an uncompressed state and the magnetic field causes the resilient member to transition from the uncompressed state to a compressed state.

7. The method according to claim 1, wherein the first condition comprises at least one of the following:

a locking a lid in a closed position;

expiration of a pre-defined period of time;

a start of a particular iteration of vacuum and sealing operations performed by the VPA;

an excessive temperature of a heat sealing element;

an excess of fluid in the container or a vacuum chamber of the VPA; and

an excess of liquid in a drip tray of the VPA.

8. The method according to claim 1, further comprising terminating the application of the magnetic field in proximity to the first component when the first condition no longer exists or a second condition is detected.

9. The method according to claim 8, wherein the second condition comprises at least one of the following:

expiration of a pre-defined period of time;

a completion of a particular iteration of vacuum operations performed by the VPA;

a start of a particular iteration of heat sealing operations performed by the VPA;

a reduction of a temperature of a heat sealing element to at least a first threshold level;

a reduction in a fluid pressure level within the container or a vacuum chamber of the VPA to at least a second threshold level; and

a reduction of a liquid level in a drip tray of the VPA to at least a third threshold level.

10. The method according to claim 1, further comprising moving the first component into range of the magnetic field using a mechanical retraction structure.

11. The method according to claim 10, further comprising manually actuating the mechanical retraction structure by depressing a lever of a latch mechanism configured to lock a lid of the VPA in a closed position.

12. A Vacuum Packaging Appliance (“VPA”), comprising:

a first component configured to normally be in an engaged position in which the first component facilitates a formation of a heat seal along an open end of a container disposed within the VPA;

at least one sensor configured to detect an existence of at least one first condition associated with the VPA; and

at least one magnet configured to apply a magnetic field in proximity to the first component when the first condition is detected, whereby the first component is at least maintained in an unengaged position in which the first component no longer facilitates the formation of the heat seal.

13. The system according to claim 12, wherein the magnetic field is generated through a supply of current to at least one electro-magnet disposed within a base or a pivoting lid of the VPA.

14. The system according to claim 12, wherein the first component is formed of a ferrous material or has a ferrous material coupled thereto such that the magnetic field causes the first component to be transitioned from the engaged position to the unengaged position.

15. The system according to claim 12, wherein the first component comprises a support structure for a heat sealing strip configured to apply heat to the open end of the container during heat sealing operations of the VPA or a bumper configured to apply pressure to the open end of the container during heat sealing operations of the VPA.

16. The system according to claim 12, further comprising a resilient member disposed within a base of the VPA and configured to bias the first component into the engaged position.

17. The system according to claim 16, wherein the resilient member is a spring normally in an uncompressed state and the magnetic field causes the resilient member to transition from the uncompressed state to a compressed state.

18. The system according to claim 12, wherein the first condition comprises at least one of the following:

expiration of a pre-defined period of time;

an excessive temperature of a heat sealing element;

an excess of fluid in the container or a vacuum chamber of the VPA; and

an excess of liquid in a drip tray of the VPA.

19. The system according to claim 12, wherein application of the magnetic field in proximity to the first component is terminated when the first condition no longer exists or a second condition is detected.

20. The system according to claim 19, wherein the second condition comprises at least one of the following:

expiration of a pre-defined period of time;

21. The system according to claim 12, further comprising a mechanical retraction structure configured to move the first component into range of the magnetic field.

22. The system according to claim 21, further comprising a lever configured to (a) actuate the mechanical retraction structure and (b) lock a lid of the VPA in a closed position when depressed.