Fluid sensing in a drip tray

Abstract

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.

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.