Patent Application
20210113008
This invention relates generally to pressure cookers and, more particularly, to mechanism for releasing pressure from a pressure cooker via a user control input or automatically at the end of a cooking cycle.
Pressure cookers operate by cooking foodstuff under pressure, which accelerates the cooking process. In order to cook under pressure, pressure cookers heat a sealed internal chamber containing the food causing the existing gas to expand. Expanding pressure in a sealed chamber increases pressure and there is no need to pump additional gas into the vessel.
After the pressure cooker has finished cooking food, those cookers known in the art commonly allow release of the internal pressure in three different ways. First, pressure cookers may utilize a “natural release,” in which the vessel is allowed to gradually cool down, thereby allowing the gas inside to contract until the pressure subsides. This can occur as the high pressure gas escapes through gaskets to ambient conditions. However, natural release may have several drawbacks. A user cannot open the pressure cooker while the chamber is pressurized beyond a threshold amount. Therefore, due to the amount of additional time that food remains in the pressure cooker during natural release, some food may end up overcooked. It can also be unclear to the user when the appliance is able to be opened
As an alternative to natural release, pressure cookers may allow for a “quick release” option. A quick release typically involves manually opening a vent on the cooker to allow pressurized gases to quickly escape from the internal chamber. The gas is heated would almost always contain vaporized fluid (steam). The quick release option may also have several drawbacks. For instance, for some foods, such as pasta or soup, rapid release of gas may cause the liquid within the chamber to begin to foam, which may overflow through the vent pipe and cause spillage and can soil the release valve for future operation. A user has to exhibit caution when using a manual release valve as well due to the release of high temperature gas. Therefore, it may be desirable for a pressure cooker to allow users to select whether to use a natural or quick release depending on the nature of the recipe being used and on what foods are being cooked.
Third, some pressure cookers may also use a combination of the natural and quick release, allowing gas to escape from the internal chamber of the cooker at intermittent intervals.
Many pressure cookers known in the prior art require the user to monitor the cooker in order to either turn off the heat or release the gas when the user wants the cooking to stop, depending on which release method is being used. However, requiring users to actively monitor the cooker may be inconvenient, as it may prevent users from performing other tasks while the cooking is occurring and may increase the risk of overcooking the food due to forgetfulness or accidents of planning on the part of the users.
Therefore, a pressure cooker which provides users with flexibility in automatically or remotely (i.e., not manually) releasing pressure from the cooking vessel may be desirable.
As a first aspect, embodiments of the invention are directed to a pressure cooker. The pressure cooker comprises: a base configured to provide heat to a chamber for pressure cooking; a lid that engages the base to seal the chamber; a valve in the lid configured to selectively release pressure in the chamber through the lid; a pressure release mechanism mounted to the lid and configured to engage the valve, the pressure release mechanism configured to move between resting and release positions, wherein in the resting position the valve remains in a sealed condition, and in the release position the pressure release mechanism engages the valve to unseal the valve from the lid to enable pressure in the chamber to be released through the lid; and a solenoid operatively associated with the pressure release mechanism to move the pressure release mechanism from the resting position to the release position. There is no electrical connection between the base and lid.
As a second aspect, embodiments of the invention are directed to a pressure cooker, comprising: a base configured to provide heat to a chamber for pressure cooking; a lid that engages the base to seal the chamber; a valve in the lid configured to selectively release pressure in the chamber through the lid; a pressure release mechanism mounted to the lid and configured to engage the valve, the pressure release mechanism configured to move between resting and release positions, wherein in the resting position the valve remains in a sealed condition, and in the release position the pressure release mechanism engages the valve to unseal the valve from the lid to enable pressure in the chamber to be released through the lid; and a force generator operatively associated with the pressure release mechanism to move the pressure release mechanism from the resting position to the release position. The pressure release mechanism includes a lifting member residing within the lid, the lifting member including a lifting finger that engages the valve to unseal the valve as the pressure release mechanism moves from the resting position to the release position.
As a third aspect, embodiments of the invention are directed to a pressure cooker, comprising: a base configured to provide heat to a chamber for pressure cooking; a lid that engages the base to seal the chamber; a valve in the lid configured to selectively release pressure in the chamber through the lid; and a pressure release mechanism mounted to the lid and configured to engage the valve, the pressure release mechanism configured to move between resting and release positions, wherein in the resting position the valve remains in a sealed condition, and in the release position the pressure release mechanism engages the valve to unseal the valve from the lid to enable pressure in the chamber to be released through the lid. The pressure release mechanism includes: a lifting member pivotally attached to the lid, the lifting member including a lifting finger that engages the valve to unseal the valve; a toggle member pivotally attached to the lid and engaging the lifting member; and a piston operatively connected with the toggle member. The pressure cooker further comprises a force generator operatively associated with the piston to move the piston upwardly to move the pressure release mechanism from the resting position to the release position.
The present invention is described with reference to the accompanying drawings, in which certain embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments that are pictured and described herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It will also be appreciated that the embodiments disclosed herein can be combined in any way and/or combination to provide many additional embodiments.
Like numbers refer to like elements throughout. In the figures, certain layers, components or features may be exaggerated for clarity. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Unless otherwise defined, all technical and scientific terms that are used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the below description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this disclosure, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood that when an element is referred to as being “on,” “attached to,” “connected to,” “coupled with,” “contacting,” etc., another element, it can be directly on, attached to connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on,” “directly attached to,” “directly connected to,” “directly coupled with,” or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.
Spatially relative terms, such as “under”, “below”, “above”, “over”, “upper”, “lower”, “left”, “right” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the descriptors of relative spatial relationships used herein interpreted accordingly.
As used herein, phrases such as “between X and Y” and “between about X and Y” should be interpreted to include X and Y. As used herein, phrases such as “between about X and Y” mean “between about X and about Y.” As used herein, phrases such as “from about X to Y” mean “from about X to about Y.”
Referring now to the drawings, a pressure cooker, designated broadly at 100, is shown in
The base 102 includes various components conventionally found in pressure cookers, including a control dial 101, a heating element (not shown), a controller 600 connected between the control dial 101 and the heating element, and the like. Buttons or switches can be used in place of the control dial. A separate pot 108 (
For the purposes of describing the present invention, two additional axes are illustrated in
The lid 104 includes an outer cover 120 and an inner cover 122 that create a cavity 125. A recess 124 is present in the outer cover 120 to house the valve cover 500. A face cover 126 extends between the rear portion of the inner cover 122 and the rear edge of the outer cover 120. (see
As noted above, together the base 102 and the lid 104 define the internal chamber 106 of the pressure cooker 100 (see
Referring still to
As shown in
The vertical piston 202 may be approximately cylindrical in shape and comprises magnetized material, such that the vertical piston 202 will respond to a magnetic field. A seating flange 204 extends radially outwardly at a distance from the bottom end of the vertical piston 202. An engagement section 206 is located above the seating flange 204. The top section 207 of the vertical piston 202 is configured to rest within a hollow boss 208 with the lid 104 of the pressure cooker 100. In some embodiments, the radius of the top section 207 of the vertical piston 202 may be smaller than the engagement section 206, thereby forming a shoulder. The engagement section 206 is shown as being rectangular, but in additional embodiments may have a square, circular, triangular, or other cross-section. A biasing member 209 (such as a spring) may be included, such that the biasing member 209 engages with the top surface of the engagement section 206 and a bottom surface of the boss 208. The lower end of the piston 202 extends downwardly through the hole 128 in the face cover 126.
The drive arm 210 comprises a hollow region 212, which merges with an extension 214, which rises upwardly and forwardly from the hollow region 212 before merging with a platform 216. The inner surface of the hollow region 212 is configured to receive the engagement section 206 of the vertical piston 202. Furthermore, the bottom surface of the hollow region 212 is configured to engage the seating flange 204 of the vertical piston 202. The upper surface of the hollow region 212 engages the lower end of the spring 209. In some embodiments, the platform 216 is generally horizontal and may include two wings 218 extending upwardly from lateral sides of the platform 216.
In some embodiments, the lid 104 may include two ribs 143 extending downwardly from top of the lid 104 and defining a gap therebetween. The gap between the ribs 143 may include the hollow boss 208. The vertical piston 202 may extend between the two ribs 143, such that the engagement section 206 and the hollow region 212 of the drive arm 210 are located within the gap between the ribs 143. The hollow region 212 may include at least one radially outwardly extending flange 213 configured to potentially engage with a surface of at least one rib 143 to maintain the drive arm 210 in position laterally should it tend to drift.
The toggle member 220 comprises a front segment 226 and a rear segment 224. The rear end of the rear segment 224 extends forwardly and upwardly from a position above and proximate to the platform 216 of the drive arm 210 before merging with the rear end of the front segment 226. In some embodiments, the rear end of the rear segment 224 extends between the wings 218 of the platform 216. As seen in
In the illustrated embodiment, the front end of the front segment 226 of the toggle member 220 includes a cage 228. The cage 228 comprises two vertical side walls 228v with a lateral extension 228h connecting the top end of each side wall 228v. In some embodiments, the profiles of the side walls 228v may be rectangles having arcuate bottom ends. In further embodiments, the side walls 228v may extend forwardly, but not laterally, from the front end of front segment 226.
The lifting member 230 comprises a front segment 236 and a rear segment 234. The rear end of the rear segment 234 extends forwardly from a position below and proximate to the lateral extension 228h of the cage 228 before merging with the rear end of the front segment 236. In some embodiments, the rear end of the rear segment 234 extends between the vertical walls 228v of the cage 228. The front segment 236 extends forwardly and upwardly from the rear segment 234. The lifting member 230 is pivotally attached to the lid 104 at a pivot 404 at the vertex of the front segment 236 and rear segment 234. The front segment 236 of the lifting member 230 includes a lifting finger 238. The lifting finger 238 extends below the valve cover 500.
The release mechanism 200 can be disposed in a resting position (see, e.g.,
As a result of the lowered position of the piston 202 in the recess 300, the drive arm 210 is in a lowered position. The lowered position of the platform 216 of the drive arm 210 allows the toggle member 220 to pivot about the pivot 402 so that the rear segment 224 is lowered and the front segment 226 is raised. The raised position of the front segment 226 (and the attached cage 228) in turn causes the rear segment 234 of the lifting member 230 to be raised. As such, the front segment 236 of the lifting member is pivoted to a lowered position, as is the lifting finger 238, which is positioned below the valve cover 500. Thus, the stopper 502 of the valve cover 500 is permitted to reside atop the upper vent sleeve 506, which seals the vent sleeve 506 from the outside, thereby preventing gas from the interior of the pressure cooker 100 from escaping during cooking. The weight of the valve cover 500 maintains the valve cover 500 in the lowered position.
When the solenoid 300 is activated (
As the front segment 226 moves downwardly, the lateral extension 228h of the cage 228 contacts the rear segment 234 of the lifting member 230, pushing the rear segment 234 downwardly. As the rear segment 234 moves downwardly, the lifting member 230 pivots about the hinge 404, such that the front segment 236 of the lifting member 230 moves upwardly. The lifting finger 238 then comes into contact with the bottom of the valve cover 500, causing the valve cover 500 to rise, which breaks the seal between the stopper 502 and the top of the vent sleeve 506, allowing the internal chamber 106 of the pressure cooker 100 to vent. Therefore, the activation of the solenoid 300 causes the pressure release mechanism 200 to move from the initial resting position of
After the solenoid 300 deactivates, the pressure release mechanism 200 returns to its initial resting position. In the absence of force being applied to the front segment 236 of the lifting member 230, the weight of the valve cover 500 can apply sufficient force to the front segment 236 of the lifting member 230 that the front segment 236 moves downwardly. As the front segment 236 moves downwardly, the lifting member 230 pivots about hinge 404, causing the rear segment 234 to move upwardly and contact the lateral extension 228h of the cage 228.
The force of the rear segment 234 of the lifting member 230 contacting the cage 228 of the front segment 226 of the toggle member 220 causes the front segment 226 to move upwardly. As the front segment 226 moves upwardly, the toggle member 220 pivots about the hinge 402, thereby causing the rear segment 224 to move downwardly and contact the platform 216 of the drive arm 210. While gravity may induce the drive arm 210 lower, compression in the spring 209 on the hollow region 212 of the drive arm 210 and on the engagement region 206 of the vertical piston 202 ensures that the drive arm 210 and vertical piston 202 are driven downwardly, such that the lower portion of the vertical piston 202 returns to the recess 303 in the base 102.
In embodiments in which the toggle member 220 extends laterally away from the platform 216 of the drive arm 210, the finger 238 may be positioned such that it is below only one side of the valve cover 500 (see
The inclusion of the ribs 143, the wings 218 on the drive arm 210 and the inclusion of the cage 228 attached to toggle member 220 may allow the individual components of the pressure release mechanism 200 to retain their positions relative to each other while the lid 104 is being rotated or moved, even though these components are not attached to each other.
Referring now to
When the solenoid 300′ is energized, the plunger 302 rises within the sleeve 304 (see
Because it utilizes a plunger-style solenoid 300′, the release mechanism 200′ can employ a piston 202′ formed of plastic material that is non-magnetic, while still maintaining a sealed area around the solenoid 300′. In addition, it can be seen that, in the resting position shown in
In addition, the silicon stopper 308 also provides a watertight (or near watertight) seal between the solenoid 300′ and the release mechanism 200′. Such a seal can prevent potential damage to the solenoid 300′ due to moisture.
As illustrated in
The use of a purely mechanical mechanism 200, 200′, 400 for opening and closing the vent sleeve 506 may allow the pressure cooker 100 to operate without power being supplied directly to the lid 104. Accordingly, there is no electrical connection between the base 102 and lid 104. Using an unpowered lid 104 may allow the lid 104 and the base 102 of the pressure cooker 100 to be more easily separable and therefore provide additional convenience in addition to decreased power consumption costs for the user. In addition, those skilled in this art will appreciate that all of the members of the mechanical mechanisms 200, 200′, 400 are mounted/captured within the lid 104 and are detachable with the lid 104 when it is removed from the base 102.
The solenoid 300 is typically controlled by the controller, which energizes and de-energizes the solenoid 300 at specific instances. In some embodiments, the controller 600 may be configured to energize the solenoid 300 (and therefore release the pressure in the cooker 100) when cooking terminates, when a certain temperature level is reached after cooking, after a specified time period, or some combination of these. In some embodiments only one of these triggering events for pressure release may be employed, whereas in others the user may have the option of selecting between techniques; such selection may be performed via any number of selection components, such as dials (which may be integrated with or separate from the dial 101), buttons, knobs, a touchscreen, etc.
Also, in some embodiments the user may choose multiple pressure release techniques. For example, in some embodiments, the controller 600 can be configured to release pressure sometime after cooking has terminated (thus following the “natural release” technique discussed above for this time period), but before all of the pressure has dissipated (thus following the “quick release” technique for the second time period). The pressure release may be based on elapsed post-cooking time, temperature, pressure, another parameter, or customer preference (e.g., during a power loss). This capability can provide the user with considerable flexibility in post-cooking pressure release in order to optimize or improve the quality of the final cooked product.
Those of skill in this art will appreciate that the pressure release mechanism 200 may take other forms. For example, more or fewer members may be employed to convert the energy of the solenoid 300 on the piston 202 into a lifting force on the valve cover 500 (as an example, the piston 202 and the drive arm 210 may be combined into a single unit rather than being two separate pieces). The members of the release mechanism 200 may be linked via pivots, pins and slots, or the like, rather than relying on non-attached engagements. Guide features other than the boss 208 and ribs 143 may be employed. A force generator other than the solenoid 300 (for example, a compressed spring that is released to actuate the mechanism) may be employed. The valve cover 500 may be a valve having a different form, may be attached (e.g., via a traditional or living hinge) to the lid 104, and/or may require user manipulation to seal (e.g., the valve may require the user to press or rotate it into place in the vent sleeve 506). The vent sleeve 506 may be divided into a two-part sleeve that provides fluid communication between the chamber 106 and the external environment. Other variations may also be employed.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.
