This invention relates generally to food preparation devices, including devices for chopping or slicing onions, tomatoes, potatoes, mushroom, carrots, and the like.
In preparing food it is often required to slice vegetables such as onion, potato, or tomato into small pieces. Most commonly, this is done by using knife. There are other specially designed devices for chopping foods, but none is particularly well suited for chopping onion, tomato etc. in an easy and efficient manner.
One exemplary and specially designed device for chopping onions, potato, tomato etc. includes an array of rectangular projections that can be pressed downward to push the food and vegetables through a grid of blades (see U.S. patent application publication 2007/0125210 A1). In this device, the blades are always immoveable. This device can not slice the vegetables with stiff skin or outer layer, or the vegetables that are too soft or hard, in an efficient manner. In such devices, during the process of chopping, outer stiffer layer gets stuck on the grid and vegetables can not be chopped completely. With the soft vegetables such as tomatoes, the vegetables get squashed during the process of chopping. There is, therefore, a need for an improved food or vegetable chopping or slicing device that can work for all kinds of foods, fruits and vegetables.
It is an objective of the invention to provide blade sets that are orthogonally configured and are capable moving/oscillating in a lateral reciprocal direction. The individual blades in each blade sets are substantially parallel. Each set of parallel blades are supported on both sides by two supporting frames. The cutting edges of the both sets of blades lie substantially in the same plane. Rectangular cut outs are provided in each blade in periodic manner such that one set of blade can be configured orthogonally to another set of blade by bringing the cut out portions close to one another. The cut outs also allow for the cutting edges of each set of blades lying in the same plane. The network of blades thus formed provides reciprocally moveable blades configured at right angles with generally squared openings. In two blade sets, one set of blade is capable to move reciprocally along x-axis and other set of blade is capable to move reciprocally along y-axis and both the motion can be independent of one another.
The supporting frame of the blade sets have extensions which are designed to a snap fit to a linearly moveable part of a linear rail. The linearly moveable part of the linear rail is connected to a means (e.g. an electric motor that rotates an eccentric cam to produce a linear reciprocal motion) that can provide a linearly reciprocating motion/action to the moveable blades.
A lid is provided which is hinged on the top surface at one end of the housing such that it can be pressed downward toward the blade sets pressing the food through the opening formed by the orthogonally configured sets. In a referred embodiment, a force or pressure sensor is provided underneath the linear rail to detect the pressure exerted on the blades sets during the process of food/vegetable chopping.
A controller is provided to control the reciprocal action of the blade sets according to users' selection, or according to signal from the sensor. According to an embodiment, the controller receives the force or pressure signal from the sensor and uses a look up table to get the corresponding pulse width modulation signal (PWM). The controller sends the corresponding PWM signal to the electric motor to adjust the speed of the motor and thus to adjust the linear reciprocal oscillation of the blade sets according to the pressure exerted on the blades so that smooth and fast chopping of the food can be done. The controller continues to send the same PWM signal to the electric motor unless the pressure sensor signal changes in which case the controller sends the adjusted PWM signal to the motor to change the speed of the motor and thus to change the reciprocating motion/action of the blade sets according to the new pressure/force signal. In this way, the controller is capable of changing the reciprocal oscillation/motion according to the pressure exerted on the blade sets by the food being chopped to provide a smooth and controlled chopping of the food.
In a preferred embodiment, the sensor is a piezoelectric, or a capacitive, or any other pressure sensor that is capable of sensing the pressure exerted on the blade sets.
In another embodiment, the sensor may be positioned at any other locations such as on the surface of the lid that faces the blade sets.
In another preferred embodiment, a user setting arrangement is provided wherein a user is allowed to select a reciprocating motion/action pattern of the blades. Several reciprocating oscillation patterns can be saved in the look up table in the form of PWM signal. When a user selects a particular pattern of the reciprocating motion, the corresponding PWM signal is sent to the motor by the controller to produce user selected oscillation patterns.
In another embodiment, the user is allowed to select whether he/she wants to produce reciprocal motion on both sets of blades or one set of blades only.
In yet another embodiment, a voltage sensor is provided to sense the predetermined limit of the voltage across the motor. If the predetermined value of the voltage is reached, the controller sends a signal to shut the motor down to by cutting off the current so that equipment can be saved from being damaged.
When the food is completely chopped off or processed, the pressure on the blade sets decreases to a minimum level which will be sensed by the sensor, and corresponding signal is sent to the controller. In an embodiment, the controller automatically turns off the motor when the pressure sensor signal is under a predetermined lower limit.
In another preferred embodiment, three linear rails are provided for each blade sets for providing support and linear reciprocal motion/action/oscillation. In the preferred embodiment, the three linear rails are configured in a triangular position. Two linear rails are configured in one side of the frame and the third on the other side of the frame. All the three linear rails can snap fit to a snap fitting means of the support frame of the blade and are moveable along the axial direction of the blade sets. The electric motor provides reciprocating action via the third linear rail in the following way. The shaft of the electric motor is connected to an eccentric cam which converts rotational motion into a linear motion. A cam follower is connected between the eccentric cam and one end of the moveable part of the linear rail. Thus a linear reciprocal motion is coupled to the moveable part of the linear rail. The blade sets are connected to the moveable part of the linear rail. The linear rails not only help transferring the linear reciprocal motion to the blade sets, but also provide the reciprocal motion substantially along the axial line of the blade sets. The linear rails also provide support to the blade sets. The triangular configuration of the motor and the rail provide a smooth coupling of the reciprocal motion to the blades sets. The triangular configuration also provides an easy vertical and planar adjustment of the blade sets when needed. Another set of blades is also provided similar arrangement of the blade sets.
In another embodiment, four linear rails are configured in rectangular positions for each blade sets, and electric motor and fifth linear rail are arranged in one side of the support frame and are substantially positioned at the centre of the frame.
In another embodiment, six linear rails and one motor are coupled to each blade sets wherein four linear rails are connected at four corners, two linear rails are connected substantially at the center of the support frame on both sides, and the electric motor is coupled to one of the rail connected at the center.
In a preferred embodiment, housing is provided for the linear rails, electric motors, and sensors. The blade sets can be removeably mounted on the linear rails externally. In one embodiment, the blade sets snap fit to the linear rail so that they can be removed, washed or cleaned and snap fitted back to the rails of the housing. A slideable container is provided which can be slide in the space just under the orthogonal blades sets and can be used to collect the processed food. The slidable container may be removable.
A lid is provided which is hinged one the top and one end of the housing such that it can be pressed downward toward the blade sets pressing food through the opening. Optionally, small projections that extend downward can be provided on the surface of the lid that faces the blades. The projections can help the food pass through the rectangular opening of the blade sets as the lid is pressed to process the food through the blade sets. The projections on the lid are sized and located within the lid such that when the lid is closed a projection fits within each of the blade openings.
in
in
a shows the side view of one embodiment of blade. The saw at the top of the blade is not shown.
b shows side view of one embodiment of another blade. The saw at the top of the blade is not shown.
c shows cross section through a blade along its axis when the blade sets are orthogonally configured. The saw at the top of the blade is not shown.
In a preferred embodiment, the depth and width of the cut outs are chosen such that one set can be put over the other set in orthogonal configuration (
In another preferred embodiment, the depth of the cut is slightly higher than the half of the width of the blade. In operation, such cuts allow for the blades to have linear reciprocal oscillation without touching each other. Different depths of the cut outs can also be chosen based on needs. The width of the cut out can be changed to provide various amplitude of linear reciprocal oscillation of the blade sets.
Now the operation of the device is described in according to one embodiment of the device (
In another preferred embodiment, after powering on, if the user has not selected any oscillation pattern, the controller gets a pressure/force signal from the sensor which is described below. As the user presses the lid toward the blade set to push the food through the blade sets, the force of the user is coupled to the linear rail and to the sensor which send the signal to the controller. The controller selects a particular pulse width modulation (PWM) value from the look up table according to the pressure sensor signal from the sensor 82. As the food or vegetables is placed on the blades sets and is pressed by the lid, the pressure exerted by the vegetable on the blade sets is transformed onto the sensor 82 via linear rail. If the food or vegetable is much harder/stiffer, and is not chopped easily at the beginning or at any time during the process, and user attempts to chop the food by pressing the lid with a higher force, the sensor automatically detects the higher force/pressure signal and transmits the signal to the controller. The controller then selects another PWM signal from the look up table corresponding to new pressure value. In this way the oscillation frequency of the blade sets are automatically changed if more harder/stiffer food is needed to be processed. The present device automatically detects the need of higher oscillations for the food to be chopped based on user response during the use of the device. In other words, the device can dynamically change the oscillation pattern of the device according to the user response (such as user changing his pressure on the lid) during the chopping process. This process makes the food chopping process lot faster and easier without damaging the integrity of the food.
In another embodiment, the linear rails are supported by spring mechanism so that steady force is exerted on the food during the reciprocating action of the blade set. Spring mechanism also helps sensor for the smooth measurement of the pressure/force exerted on the blade sets.
In another embodiment, only one blade set is used for food cutting or chopping process to obtain the slices of the food.
In another embodiment of the device a voltage sensor is connected across the electric motor (see
In this invention, the blade includes blades having cutting edge with or without saw. The term U or rectangular shaped cut outs implies the region where U or rectangular shaped region of the blade has been removed by cutting or by any other means.
This application claims priority under 35 USC 119(e) (1) of U.S. Provisional Patent Application Ser. No. 61/125,551 filed on Apr. 25, 2008.
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1999449 | Erickson | Apr 1935 | A |
2327018 | Criner | Aug 1943 | A |
3463211 | Holz | Aug 1969 | A |
3614970 | Webb | Oct 1971 | A |
4051757 | Reifenhauser et al. | Oct 1977 | A |
4771664 | Holz | Sep 1988 | A |
7762169 | Kaposi | Jul 2010 | B2 |
Number | Date | Country | |
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20090277343 A1 | Nov 2009 | US |
Number | Date | Country | |
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61125551 | Apr 2008 | US |