Fluid sensing in a drip tray
A vacuum packaging appliance that detects the amount of liquid present while evacuating and sealing a container is disclosed. The appliance comprises a lid adapted to define a vacuum chamber when it is moved to a closed position relative to a trough in the base of the device. The trough in the lower portion of the device contains a heat-sealing element used to seal the contents of the bag once the vacuum packaging is complete. Disclosed are several embodiments relating to a liquid sensor molded into the walls of the trough. The liquid sensor comprises two electrodes that may be located on opposite sides of the trough or on the same side of the trough. When liquid is present in the trough, the capacitance and resistance between the electrodes changes, thereby sending a signal to a controller indicative of the amount of liquid within the trough while the container is being evacuated. The exact amount of liquid present is compared to a predetermined level of liquid. A vacuum pump controller may suspend operations if the amount of detected liquid exceeds a predetermined amount. The heat-sealing element is also controlled in accordance with the amount of liquid sensed in the trough. The amount of liquid sensed is also indicated to the operator.
The present application claims priority to Albritton et al.'s U.S. provisional application No. 60/492,046, filed Jul. 31, 2003, and entitled FLUID SENSING IN A DRIP TRAY, the contents of which are incorporated herein by reference. The present application is also related to Albritton et al's U.S. provisional application No. 60/491,876, filed Jul. 31, 2003, and entitled HEAT SEALING ELEMENT AND CONTROL OF SAME, the contents of which are incorporated herein by reference.
TECHNICAL FIELDThe invention relates to a vacuum packaging appliance for packaging products and more particularly to sensing liquid in a trough of the vacuum packaging appliance while evacuating a container and controlling a vacuum pump and heat sealing elements in accordance with the detected amount of liquid.
BACKGROUND OF THE INVENTIONPresently, various appliances and methods are used for the purpose of vacuum sealing plastic bags and containers to protect perishables, such as foodstuffs, and other products against oxidation. Conventional commercial appliances and some consumer appliances are generally expensive to manufacture, complex in construction and/or cumbersome to operate. There are many different types of these vacuum sealing appliances primarily used for commercial packaging purposes.
One type of conventional vacuum sealing appliance uses a vacuum nozzle that is inserted within a plastic bag for evacuation purposes. Although adaptable for low-volume home use, this type of appliance is cumbersome to use and normally requires a liquid separator or filter to prevent liquids or powders, retained within the bag, from being drawn into a vacuum pump connected to the nozzle.
Still another known vacuum sealing appliance places a portion of a bag, containing a product to be packaged, in a first vacuum chamber and extends an open end or neck of the bag into a second vacuum chamber. The first vacuum chamber is then evacuated to expand the neck of the bag to isolate the chambers from each other. Then a vacuum is drawn in the second vacuum chamber to evacuate the bag. Thus, isolation of the two chambers from each other, during evacuation of the second vacuum chamber, is dependent on the physical properties composing the neck of the bag (which is intended to form a static seal between the two chambers) and very close synchronization and calibration of the evacuation and sealing procedures and controls therefor. A vacuum sealing appliance of this type is disclosed in U.S. Pat. No. 3,928,938, for example.
A substantial problem with these and other prior art vacuum packaging appliances is that liquids evacuated from the bag contents collect in the vacuum chamber and may damage the vacuum pump itself. The presence of these unwanted liquids also causes failures in the heat sealing operations. For example, the temperature of the inner layer of a conventional vacuum sealable bag must be raised to approximately 130 degrees in order to melt the internal heat sealing layer of the bag. Energy supplied to the heat sealing elements is wasted on burning off these unwanted liquids, therefore the temperature of the inside layer of the bag does not reach the required level for heat sealing to occur.
Therefore, there exists a need for a vacuum packaging apparatus that is able to sense the presence and amount of liquid while evacuating a container. In addition to the sensing of liquid within the appliance, it would also be desirable to control operations of the vacuum pump itself and to further control the heat sealing operations in accordance with the amount of liquid sensed.
SUMMARY OF THE INVENTIONA vacuum packaging appliance that detects the amount of liquid present while evacuating and sealing a container is disclosed. The appliance comprises a lid adapted to define a vacuum chamber when it is moved to a closed position relative to a trough in the base of the device. A heat sealing element is used to seal the contents of the bag once the vacuum packaging is complete. Disclosed are several embodiments relating to a liquid sensor molded into the walls of the trough. The liquid sensor comprises two electrodes that may be located on opposite sides of the trough or on the same side of the trough.
When liquid is present in the trough, the capacitance and resistance between the electrodes changes, thereby sending a signal to a controller indicative of the amount of liquid within the trough while the container is being evacuated. The exact amount of liquid present is compared to a predetermined level of liquid. A vacuum pump controller may suspend operations if the amount of detected liquid exceeds a predetermined amount. The heat sealing element is also controlled in accordance with the amount of liquid sensed in the trough. The amount of liquid sensed is also indicated to the operator.
Other embodiments of the present invention include positioning the liquid sensing electrodes on opposite sides of the trough, on the same side of the trough, and on the top of the trough. The liquid sensors are also capable of providing a binary signal indicating the amount of liquid is above a predetermined level or an analog signal indicating the exact amount of liquid detected. The liquid sensing electrodes are molded into the trough walls to avoid direct contact with any liquid in order to avoid corrosion.
The present invention also includes a plurality of methods for controlling a vacuum packaging appliance for evacuating a container. These methods include controlling both the vacuum pump to obtain a desired vacuum within a vacuum packaging receptacle and sensing an amount of liquid in the vacuum circuit trough. The methods further determine an actuation control signal for energizing the heat sealing element as a function of the sensed amount of liquid in the vacuum circuit trough, and suspending operations of the vacuum pump based on the amount of sensed liquid.
The present invention therefore protects the vacuum packaging appliance and also greatly enhances the heat sealing operations of vacuum packaging appliances based on the detected amount of liquid which minimizes the amount of wasted bag material due to faulty sealing.
BRIEF DESCRIPTION OF THE DRAWINGS
For clarity of presentation, the FIGS. are grouped and discussed as follows.
The lid includes a blade handle 108 that is associated with a blade (not shown) on the inside of the lid 102 of the vacuum packaging appliance 100. The blade handle 108 is slideably engaged within a slot 110 that extends substantially the entire length of the vacuum packaging appliance 100. Although the embodiment shown in
Also shown in the embodiment of
The control panel 118 has rotary dial control 304, a cancel control 306, an instant seal control 308, a extended vacuum control 310, an accessory port 312 and an indicator lights 314. These indicator lights (green, yellow and red) provide feedback to the user indicative of the amount of liquid sensed in the appliance trough. However in alternate embodiments, various other controls maybe included in the control panel 118 and/or various controls maybe excluded from the control panel 118. The controls shown operate with a controller and liquid sensors as described below.
The rotary dial 304 has multiple positions that can control various aspects of the vacuum packaging appliance 100. For example, the rotary dial 304 has five positions: Accessory, 1, 2, 3 and Seal Only. However in alternate embodiments, the rotary dial may have more or fewer settings that can control various aspects of the vacuum packaging appliance 100. When the rotary dial 304 is in the accessory position, the accessory port 312 is activated and accessories (not shown) can be attached to the vacuum packaging appliance 100 either directly or via a vacuum hose (not shown). When the rotary dial 304 is in any position other than the accessory position, the accessory port 312 is sealed off and a vacuum is not drawn through the accessory port 312. Sealing off of the accessory port 312 can be accomplished by other convenient mechanism.
Positions 1, 2 and 3 allow the user to control the length of time the heat sealing element is active. Position 1 may activate the sealing mechanism for a first predetermined period producing a fragile or light seal. Position 2 may activate the sealing mechanism for a second predetermined period producing a medium heat seal, and position 3 may activate the sealing mechanism for a third predetermined period resulting in a heavy heat seal. Thus, the user can select the duration of the sealing process. For example sealing potato chips or fruit may require a light seal, whereas sealing meat would require a heavy seal.
The seal only position allows a user to use the apparatus to operate the sealing mechanism 420 (
After repetitive uses the heat sealing elements may become hot, therefore it requires less electrical power to heat the sealing elements to a sealing temperature. The control of the heat sealing elements is described below with reference to
The control panel includes a cancel button 306. The cancel button 306 allows a user to cancel a vacuum operation or sealing operation at any time during the operation. In the embodiment shown in
The control panel 118 also includes an instant seal button 308. The instant seal button 308 allows a user to terminate the evacuation process and begin the sealing process at any time during operation of the vacuum packaging appliance 100. By way of example, a user may desire to only partially evacuate a container or not evacuate a container at all. Thus, the user may engage the container in the device and seal the container either without drawing a vacuum in the container or while drawing a vacuum in the container before the device begins automatically sealing the container.
In the embodiment shown in
An indicator light 314 serves to notify a user of the status of the vacuum packaging appliance 100. In the embodiment shown in
The lid also includes a sealing gasket 410, a cutting mechanism 412 that includes the handle and the blade (not shown) and a heat sealing element 433. The heat sealing element 433 touches electrical contacts 431 and 432 on the base of the device when the lid is closed. In this manner power is supplied to the heat sealing element via the contacts. This is desirable, as no power cord is necessary to run through the device hinges into the lid 102. This reduces the complexity of the device itself In alternate embodiments, the heat sealing element may be 2 wires or a wider element to ensure a proper heat seal. In other embodiments the heat sealing wires are located on the base of the appliance 100.
The base 104 of the vacuum packaging appliance 100 also includes an electromechanical switch 416, and evacuation apertures 418. In the embodiment shown in
The base 104 of the vacuum packaging appliance 100 has a recess 422 that is adapted to hold container material 424. The container material 424 is a roll of flattened, tubular container material and is supported on rotational supports 426. The rotation supports 426 are designed to engage the ends of the roll of container material 424 and rotate freely within the recess 422. Each rotation support 426 has grooves at its perimeter to facilitate rotation of the rotational support 426 and the roll of container material 424.
As shown in
The base 104 of the vacuum packaging appliance 100 further includes a groove 428 that is located in front of the trough 430. The groove 428 is positioned in the base 104 such that when the lid 102 is in a closed position, the cutting mechanism 412 is substantially vertically aligned with the groove 428. In operation, a user can move the handle 108 on the lid 102 within the slot 110 that will cause the cutting mechanism 412 to travel within the groove 428. If container material is present within the groove 428, the container material will be cut by the cutting mechanism 412. The cutting mechanism 412 is a safety cutting mechanism designed to reduce the risk of injury to a user.
The thermal sealing mechanism 433 includes one or more electrically conductive wires that produce heat when a voltage differential is applied across the length of the wire. In the embodiment shown, the electrically conductive wires are covered with a Teflon tape. However, in alternate embodiments, the wires maybe exposed or wrapped in a material. When the lid 102 is in a closed position, the sealing gasket 406 presses against the sealing mechanism 433. If the sealing mechanism 433 is activated and container material 424 is disposed between the sealing gasket 406 and the sealing mechanism 433, the container material 424 can be hermetically sealed.
Although the appliance 100 is described as including a sealing mechanism 433 that is integrated with the appliance, in alternate embodiments, the sealing mechanism 433 may be on the base of the device while the electrical contacts are located on the lid. Additionally in alternate embodiments, various other placements of the heat sealing mechanisms 433 may be employed in order to seal the container material 424.
In operation, when the lid 102 is in a closed position and is depressed such that the protrusion 414 actuates the electromechanical switch 416, the vacuum pump or source 434 is activated. In the embodiment shown in
For cleaning purposes, the trough 430 is removable from the base 104 of the vacuum packaging appliance 100 through the door 114. In the embodiment shown in
In operation, a user inserts an open end of a container, such as a flexible bag, into the trough 430 or attaches a container to the accessory port 312. The user then selects a setting on the rotary dial 304, closes the lid 102 and depresses the lid 102 past the closed position to actuate the electromechanical switch 416 with the protrusion 414. The vacuum pump or source will then evacuate the latch chambers 402 to hold the lid 102 relative to the base 104.
Once the lid 102 is secured relative to the base 104 by the latch chambers 402, the primary evacuation chamber 408 and the trough 430 are evacuated thus evacuating the open container inserted into the trough 430. When the vacuum strength reaches a predetermined level, the sealing mechanism will be activated to seal the container, if it is inserted into the trough 430. The evacuated and sealed container may then be released from the vacuum packaging appliance 100.
The protrusion 502 helps to seal the evacuation chamber and trough 430 and also helps to keep the container 504 in position while the evacuation process is performed. Once the evacuation process is complete, the heat sealing elements 420 are activated. The front side of the gasket 406 maintains the container 504 in contact with the sealing elements 420 while the heat sealing process is performed. As described above, the container 504 has a heat sensitive layer that forms an airtight seal when activated by the elements 420. In this manner the container is evacuated and sealed.
The trough 430 is mounted in the recess 502 such that the flanges 604 of the trough 430 are positioned below the retention flanges 504 of the recess 502. Thus, vertical movement of the trough 430 with the recess 502 is substantially inhibited. The embodiment shown also shows that the base of the vacuum packaging appliance 100 includes a roll of container material 424 that is stored within the recess 422 within the appliance 100 and a vacuum pump 434.
The embodiment of
In this embodiment, the electrodes 91A and 91B are molded into the sides of the plastic trough 430. A material such as aluminum may be used for these electrodes. These liquid sensors feed signals back to a controller as shown in
The controller 92 uses the signals to determine if a predetermined amount of liquid is in the trough and may adjust the amount of current supplied to the heat sealing elements in accordance with the detected amount of liquid. One feature of this embodiment is that the actual amount of liquid may be sensed. The signal produced by the electrodes 91A and 91B is analog in nature, so the exact level of liquid within the trough may be detected. Other embodiments of the invention include producing a binary signal that indicates that the amount of liquid is above or below a predetermined level. As will be described below, the heat sealing element controller 92 uses the information from the liquid sensor to modify the operator selected type of heat seal and to notify the operator of the sensed level of liquid in the appliance.
A schematic diagram of the control circuitry of the heat sealing element in conjunction with the liquid sensing electrodes is shown in
The controller 92 may be an ASIC device, a programmable logic device PLD or conventional microprocessor chip that contains the necessary software and logic means to control the operation of the heat sealing process. This further includes storing various times dependent on the type of heat seal selected by the operator. For example a heavy seal may be for a duration of 5 seconds while a light seal may energize the sealing elements 420 for one second. The controller 92 also includes timing circuitry designed to actuate and control the temperature of the sealing element based on the current used. For example, if multiple heavy seals are performed in a predetermined time period, the controller instigates a wait period in which the heat sealing element is allowed to cool. This prevents heat sealing element overheating which results in damaging of the vacuum containers and wasted materials. Patent application Ser. No. 60/491,876, entitled “Heat Sealing Element and Control of Same”, by inventors Charles Wade Albritton and Landon Higer, filed Jul. 31, 2003, is also incorporated by reference to show further details of the controller 92.
As mentioned above, problems with overheating and faulty sealing result from inaccurate temperatures of the heat sealing elements 420. The liquid sensor electrodes 91A and 91B allow the controller 92 to supply more or less electrical power to the elements based on this detected level of liquid in the trough 430. For example a standard heavy seal would be to supply a control signal current to the elements for 5 seconds creating a vacuum bag temperature of 130 degrees (required to melt the interior heat sealing layer). If the sensors indicate a high liquid content, a heavy seal may be produced by increasing the control signal current for a total duration of 6 seconds. If a low level of liquid is sensed, the control signal that actuates the sealing elements will not be modified by the controller 92.
The controller also sends a signal to the control panel 118 that contains indicators to alert the operator as to the level of liquid detected. For example a green light would indicate a low level of liquid, a yellow light would indicate a medium level of liquid, and a red light would indicate a high level of liquid. The controller may also shut down appliance operations if the level of liquid is above a predetermined level. In this manner the controller 92 monitors the presence and amount of liquid and is able to modify the control signals to the heat sealing elements and indicate this information to the operator.
Vacuum sensor 94 sends a signal back to the controller 93 indicative of the amount of vacuum in the vacuum circuit and trough. Once the controller determines that a proper vacuum is obtained, the vacuum pump may be shut down. The vacuum pump 434 may also be enabled or disabled in response to a user activated switch on the control panel 118. The vacuum pump controller also controls the pump 434 in accordance with the other setting as found on control panel 118 and as described with reference to
Also as described above the step of providing feedback to the operator includes controlling the lights on the control panel to display to the operator the exact amount of sensed liquid. As shown in
By incorporating the liquid sensing electrodes into the trough of the appliance, the heat seal may be controlled in a more precise manner, thereby resulting in less bag waste. This is a substantial improvement over prior art devices that are incapable of monitoring and adjusting the heat sealing process in accordance with the amount of liquid detected during the evacuation process. Other embodiments of the present invention include controlling the heat sealing elements in accordance with a plurality of input parameters such as, for example, the type of heat seal selected by the operator, the amount of liquid sensed in the trough, and the temperature of the heat sealing elements.
As will be appreciated, the activation of the pump can be initiated manually or automatically upon closure of the lid. The operation may also be enhanced by preventing activation of the pump when the liquid level is initially at a potentially unsafe level.
As long as the level of detected liquid is below the safety level, the vacuum pump can remain on. In step S1210 it is determined if the required level of vacuum (vacuum end point) has been reached. If this is the case the vacuum controller will then deactivate the pump in step S1214. If the vacuum end point has not been reached, the vacuum pump can remain on. It is also determined in step S1216 if the user has operated a switch on the control panel to deactivate the vacuum pump. If this is the case, the vacuum pump is shut of in step S1214. If the user has not indicated that the vacuum process be stopped then the controller will continue to operate the vacuum pump. The process described with reference to
The sensed liquid level information can also be incorporated into the evacuation and heat seal processes. For example, when high levels of liquid are present, the evacuation could be performed at a slower pace and the heat seal performed at a higher energization level.
It will be understood by those skilled in the art that the above-presented description is provided by way of example only and is not intended to be limiting in anyway. Those skilled in the art will readily understand that numerous other embodiments of the invention are contemplated and possible which meet the scope and spirit of the invention.
Claims
1. A vacuum packaging appliance for evacuating a container comprising:
- a base defining an upper support surface adapted to receive an open end of a container;
- a lid operatively associated with said base, said lid and said base defining a vacuum circuit therebetween to receive said open end of said container;
- at least one gasket surrounding said vacuum circuit for directly engaging said container such that said open end of said container is operatively associated with said vacuum circuit;
- a vacuum pump operatively associated with said vacuum circuit for selectively evacuating said vacuum circuit and said operatively associated container;
- a trough coupled to the base for receiving the open end of a container and collecting contents taken from the container while evacuating said container, and
- a liquid sensor mounted on the trough in order to sense liquid in the trough while evacuating the container.
2. The vacuum packaging appliance of claim 1 wherein said liquid sensor is comprised of two electrodes molded into the walls of the trough.
3. The vacuum packaging appliance of claim 2 wherein the two electrodes are molded into walls on opposite sides of the trough.
4. The vacuum packaging appliance of claim 2 wherein the two electrodes are both molded into one wall of the trough.
5. The vacuum packaging appliance of claim 2 wherein the two electrodes are mounted on top of the trough.
6. The vacuum packaging appliance of claim 3 wherein the presence of liquid in the trough changes the capacitance between the two electrodes.
7. The vacuum packaging appliance of claim 3 further comprising providing feedback to an operator related to the liquid level.
8. The vacuum packaging appliance of claim 1 further comprising a heat sealing element arranged to seal an open end of said operatively associated container.
9. The vacuum packaging appliance of claim 8 further comprising a heat sealing element controller operable to actuate said heat sealing element, and wherein said heat sealing element controller is responsive to the liquid sensor such that the heat sealing element is energized as a function of the liquid level.
10. The vacuum packaging appliance of claim 9 wherein said liquid sensor sends an analog signal back to said heat sealing element controller indicative of the exact amount of liquid sensed in the trough.
11. The vacuum packaging appliance of claim 9 wherein said liquid sensor sends a digital signal back to said heat sealing element controller indicating that amount of liquid sensed in the trough has exceeded a predetermined level.
12. A method for controlling a vacuum packaging appliance, said vacuum packaging appliance including a heat sealing element, a vacuum circuit including a trough, and a vacuum pump, said vacuum pump operable to evacuate gas from said vacuum circuit, said heat sealing element operable to heat seal a vacuum packaging receptacle, said method comprising:
- coupling said vacuum packaging receptacle to said vacuum circuit;
- hermetically separating said vacuum circuit from ambient;
- operating said vacuum pump to obtain a desired vacuum within said vacuum packaging receptacle;
- sensing an amount of liquid in the vacuum circuit trough;
- determining an actuation control signal for energizing said heat sealing element as a function of the sensed amount of liquid in the vacuum circuit trough; and
- applying said actuation control signal to said heat sealing element.
13. A method for controlling a vacuum packaging appliance as recited in claim 12, further including the act of providing two electrodes molded into walls of the vacuum circuit trough to sense the amount of liquid in the vacuum circuit trough.
14. A method for controlling a vacuum packaging appliance as recited in claim 13, wherein a capacitance between said two electrodes changes as a function of the amount of liquid in the vacuum circuit trough.
15. A method for controlling a vacuum packaging appliance as recited in claim 13, wherein the vacuum packaging appliance may be shut off when the amount of sensed liquid exceeds a predetermined level.
16. A method for controlling a vacuum packaging appliance as recited in claim 14, wherein a signal indicating the exact level of liquid is provided.
17. A method for controlling a vacuum packaging appliance as recited in claim 14, wherein a binary signal indicating that the level of liquid is above or below a predetermined level is provided.
18. A method for controlling a vacuum packaging appliance as recited in claim 12, wherein the actuation control signal is also determined in accordance with the detected temperature of the heat sealing elements.
19. A method for controlling a vacuum packaging appliance as recited in claim 18, wherein the actuation control signal is also determined in accordance with a user input.
20. A method for controlling a vacuum packaging appliance as recited in claim 17, wherein the actuation control signal is also determined by comparing the sensed amount of liquid in the vacuum circuit trough to a predetermined level of liquid.
21. A method for controlling a vacuum packaging appliance as recited in claim 20, wherein feedback is provided to the user indicating a high, medium, or low amount of liquid in the vacuum circuit trough.
22. A vacuum packaging appliance for evacuating a container comprising:
- a trough for receiving the open end of a container and collecting contents and liquids taken from the container while evacuating said container,
- a heat sealing element for sealing the evacuated container;
- a heat sealing controller that actuates the heat sealing elements and receives a selected type of heat seal from an operator; and
- a liquid sensor that sends a signal to the heat sealing controller indicative of the amount of liquid taken from the container while evacuating said container.
23. The vacuum packaging appliance of claim 22 wherein said heat sealing controller controls the power supplied to the heat sealing elements based on both the operator selected type of seal and the amount of liquid sensed in the trough.
24. The vacuum packaging appliance of claim 23 further comprising an indicator that indicates to an operator the amount of liquid sensed in the trough.
25. The vacuum packaging appliance of claim 24 wherein the liquid sensor and temperature sensor are located in the trough.
26. A method for controlling a vacuum packaging appliance, said vacuum packaging appliance including a heat sealing element, a vacuum circuit including a trough, and a vacuum pump, said vacuum pump operable to evacuate gas from said vacuum circuit, said heat sealing element operable to heat seal a vacuum packaging receptacle, said method comprising:
- coupling said vacuum packaging receptacle to said vacuum circuit;
- hermetically separating said vacuum circuit from ambient;
- operating said vacuum pump to obtain a desired vacuum within said vacuum packaging receptacle;
- sensing an amount of liquid in the vacuum circuit trough;
- comparing the sensed amount of liquid in the vacuum circuit trough to a predetermined level of liquid;
- indicating to an operator that the level of liquid has exceeded the predetermined level; and
- suspending operations of the vacuum packaging appliance when the level of sensed liquid has exceeded the predetermined level.
27. A method for controlling a vacuum packaging appliance, said vacuum packaging appliance including a heat sealing element, a vacuum circuit including a trough, and a vacuum pump, said vacuum pump operable to evacuate gas from said vacuum circuit, said heat sealing element operable to heat seal a vacuum packaging receptacle, said method comprising:
- coupling said vacuum packaging receptacle to said vacuum circuit;
- hermetically separating said vacuum circuit from ambient;
- sensing an amount of liquid in the vacuum circuit trough;
- determining if said vacuum pump should be activated based on the sensed amount of liquid in the vacuum circuit trough.
28. A method for controlling a vacuum packaging appliance as recited in claim 27, further including the act of providing two electrodes molded into walls of the vacuum circuit trough to sense the amount of liquid in the vacuum circuit trough.
29. A method for controlling a vacuum packaging appliance as recited in claim 28, wherein a capacitance between said two electrodes changes as a function of the amount of liquid in the vacuum circuit trough.
30. A method for controlling a vacuum packaging appliance as recited in claim 28, wherein the vacuum pump may be shut off when a predetermined amount of vacuum exists within the vacuum circuit.
31. A method for controlling a vacuum packaging appliance as recited in claim 29, wherein a signal indicating the exact level of liquid is provided.
32. A method for controlling a vacuum packaging appliance as recited in claim 29, wherein a binary signal indicating that the level of liquid is above or below a predetermined level is provided.
33. A method for controlling a vacuum packaging appliance as recited in claim 27, wherein the user may deactivate the vacuum pump.
34. A vacuum packaging appliance for evacuating a container comprising:
- a vacuum pump for evacuating a vacuum circuit and the container;
- a liquid sensor located in the vacuum circuit that detects liquid in the vacuum circuit while evacuating the container;
- a vacuum sensor for detecting the amount of vacuum in the vacuum circuit;
- a control panel containing a switch for activating and deactivating the vacuum pump; and
- a vacuum pump controller that controls the activation and deactivation of the vacuum pump, wherein the vacuum pump controller is operatively connected to the liquid sensor, the vacuum sensor and the control panel to control the activation of said vacuum pump.
35. The vacuum packaging appliance of claim 34, wherein said liquid sensor is comprised of two electrodes molded into the walls of a trough arranged to capture liquids evacuated from the container.
36. The vacuum packaging appliance of claim 35 wherein the two electrodes are molded into walls on opposite sides of the trough.
37. The vacuum packaging appliance of claim 35, wherein the two electrodes are both molded into one wall of the trough.
38. The vacuum packaging appliance of claim 37, wherein the two electrodes are mounted on top of the trough.
39. The vacuum packaging appliance of claim 36, wherein the presence of liquid in the trough changes the capacitance between the two electrodes.
40. The vacuum packaging appliance of claim 36, wherein the presence and amount of liquid in the trough is indicated to an operator.
41. The vacuum packaging appliance of claim 34, wherein the vacuum pump controller deactivates the vacuum pump when the level of sensed liquid in the trough exceeds a predetermined amount.
42. The vacuum packaging appliance of claim 34, wherein the vacuum pump controller deactivates the vacuum pump in response to a user input.
43. The vacuum packaging appliance of claim 42, wherein said liquid sensor sends an analog signal back to said vacuum pump controller indicative of the exact amount of liquid sensed in the trough.
44. The vacuum packaging appliance of claim 42, wherein said liquid sensor sends a digital signal back to said vacuum pump controller indicating that amount of liquid sensed in the trough has exceeded a predetermined level.
45. The vacuum packaging appliance of claim 35, further comprising a trough being part of the vacuum circuit, the trough arranged to receive the container and to capture liquids evacuated from the container tending to prevent liquid from being pulled into and fouling the vacuum circuit and damaging the vacuum pump, the trough including a shallow pool structure located near an upper surface of the trough, the liquid sensor being disposed within the shallow pool structure.
46. The vacuum packaging appliance of claim 35, further comprising a trough being part of the vacuum circuit, the trough arranged to receive the container and to capture liquids evacuated from the container tending to prevent liquid from being pulled into and fouling the vacuum circuit and damaging the vacuum pump, the trough including a dead zone structure, the liquid sensor being disposed within the dead zone structure.
47. A vacuum packaging appliance for evacuating a container comprising:
- a vacuum pump;
- a vacuum circuit coupled to the vacuum pump whereby the vacuum pump is operable to evacuate the vacuum circuit;
- a trough coupled to the vacuum circuit via an intake, the trough arranged to receive the container and to capture liquids evacuated from the container tending to prevent liquid from being pulled into and fouling the vacuum circuit and damaging the vacuum pump, the trough and vacuum circuit arranged to evacuate the container; and
- a mechanical liquid sensor disposed within the trough, the mechanical liquid sensor operable to close the intake when necessary to prevent liquid within the trough being evacuated through the intake.
Type: Application
Filed: Jul 26, 2004
Publication Date: Feb 24, 2005
Inventors: Charles Albritton (Hercules, CA), Landen Higer (Alameda, CA), John Peters (Campbell, CA)
Application Number: 10/900,045