This disclosure relates generally to pizza ovens, barbecue grills and accessories and, more particularly, to a pizza oven grill conversion kit.
A brick oven typically bakes pizzas at temperatures ranging between 700 and 1000° F. (370 to 540° C.). Residential ovens are usually incapable of reaching higher than 500° F. In order to be able to enjoy a professionally baked pizza at home, a consumer may turn to a grill conversion kit. A pizza oven conversion kit for a grill typically involves adding parts to or modifying parts of a standard grill in an attempt to maintain an internal environment that mimics that of a pizza oven. Though grill conversion kits can in some cases achieve a high internal grill temperature, they fail to capture many key features of the pizza oven baking process.
Firstly, available pizza oven conversion kits fail to create the high sustained heat and thermal radiation patterns that are typically emitted in a brick oven. Heat distribution is key during the pizza cooking process, since a pizza is only cooked for a short time in a pizza oven (typically 2-3 minutes) due to high internal temperatures. Without proper heat emittance, a pizza may be cooked too slowly (and may become too dry), or too fast (and may become burnt or inedible), or unevenly (burnt in some spots, raw in others). Furthermore, available conversion kits do not provide ample configuration for adapting the grill to different weather conditions (e.g. wind, temperature, pressure, etc.) and often require a high degree of chef intervention to manipulate the pizza in order for it to evenly cook.
Current pizza oven conversion kits also fail to evenly heat both sides of the pizza (usually by underheating/overheating the crust and/or toppings). Current pizza oven conversion kits are also fuel inefficient and can only be used with certain types of grills or with certain types of fuel (such as charcoal).
In one aspect, a pizza oven grill conversion kit for converting a grill into a pizza oven comprises a bottom plate coupled to one or more legs of the grill. The kit also comprises a lid comprising one or more bricks. The kit also comprises a turntable having an end of a driveshaft coupled to its underside. The driveshaft extends orthogonally away from the turntable and through the bottom of the bowl. The kit also includes a motor situated below the bowl. The driveshaft also extends through the motor. Operation of the motor causes the driveshaft and the turntable to rotate. The kit also includes a height adjustment assembly, which includes a cover. An end of the driveshaft opposite to that coupled to the turntable is housed in the cover. The height adjustment assembly includes a male-threaded rod having a top end rotatably disposed within the cover. A portion of the male-threaded rod is threadedly coupled to a female-threaded portion of the bottom plate. The male-threaded rod threads through the female-threaded portion when a rotational force acts upon the male-threaded rod. Rotation of the male-threaded rod causes the male-threaded rod to adjust the vertical position of the driveshaft.
In another aspect, a brick pizza oven comprises a bowl, a plurality of legs coupled to the bowl, and a bottom plate coupled to the plurality of legs. The oven also comprises a lid comprising one or more bricks, a bottom rim of which is configured to fit a top rim of the bowl. The oven also comprises a turntable having an end of a driveshaft coupled to its underside. The driveshaft extends orthogonally away from the turntable and through the bottom of the bowl. The oven also includes a motor situated below the bowl. The driveshaft also extends through the motor. Operation of the motor causes the driveshaft and the turntable to rotate. The oven also includes a height adjustment assembly, which includes a cover. An end of the driveshaft opposite to that coupled to the turntable is housed in the cover. The height adjustment assembly includes a male-threaded rod having a top end rotatably disposed within the cover. A portion of the male-threaded rod is threadedly coupled to a female-threaded portion of the bottom plate. The male-threaded rod threads through the female-threaded portion when a rotational force acts upon the male-threaded rod. Rotation of the male-threaded rod causes the male-threaded rod to adjust the vertical position of the driveshaft.
The embodiments of this invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.
The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details.
Referring to
In another embodiment, the pizza oven grill 100 may be manufactured and shipped as a pizza oven (i.e. a standalone, portable pizza oven 100 as illustrated in
As such, the pizza oven grill 100 as illustrated in the drawings is meant to incorporate both a standalone, portable pizza oven and a converted grill. All details of the pizza oven grill 100 provided in the drawings are meant to interpreted in an illustrative, not a restrictive sense.
The pizza oven grill 100 comprises a lid 102 and a bowl 104. The lid may have a handle 106. The bowl 104 may comprise, among other components, a pizza stone 136. The bowl may be coupled to one or more legs 108. One or more of the one or more legs 108 may be coupled to a wheel 110, allowing the pizza oven grill 100 to be more easily moved. A bottom plate 118 may be coupled to one or more of the legs 108 and may be utilized as a base for a height adjustment assembly 120 and a rotator assembly 122. The height adjustment assembly 120 may be utilized to adjust the height of the pizza stone 136 within the bowl 104. The rotator assembly 122 may be utilized to rotate the pizza stone 136.
The pizza oven grill 100 shown in
In a preferred embodiment, the heating element may be housed internally within the bowl 104 and may use propane as fuel. The propane burner may provide around 110,000 BTUs of heat and may apply that heat directly or indirectly to one or more components of the pizza oven grill 100. A propane burner may be preferred in place of other fuels, such as charcoal, because a propane burner will more efficiently reach and maintain a temperature that is suitable for baking pizzas in a fuel-efficient and timely manner. For example, commercial pizza ovens typically cook pizzas within 2-3 minutes, which timing can be achieved using a propane burner. Combined with other key fuel-saving features, the pizza oven grill 100 may leave a smaller carbon footprint compared to available pizza oven grills.
The pizza oven grill 100 may be fashioned after other types of grills, such as a kamado grill, or may be a clay oven. Any type of material may be used for the lid 102, the bowl 104, or any other component of the pizza oven grill 100 and is within the scope of the exemplary embodiments described herein. Furthermore, any type of grill may be converted to a pizza oven grill by applying one or more modifications provided in a pizza oven grill conversion kit (not shown in the drawings). As such, any combination of the components or mechanisms described herein may be packaged as kits or parts for converting any grill to one that is ideal for reaching a high temperature rapidly and maintaining that high temperature for a sustained period while using little fuel.
In one embodiment, the lid 102 may be provided in a conversion kit and may be configured to retrofit the pizza oven grill 100. An original lid of the pizza oven grill may be positioned on top of the lid 102 to provide an insulating air space above the lid 102 (not shown in
A front portion of the lid 102 may comprise an opening 112 through which food may be inserted or withdrawn. On either side of the opening 112 may be mounts 114 for a visor 116 that may cover at least a portion of the opening 112 to prevent heat from escaping the internal chamber of the lid 102 and the bowl 104. The visor 114 may hinge at the mounts 114 and be tilted upwards to provide access to the internal chamber of the pizza oven grill 100 through the opening 112 (e.g. to retrieve a baked pizza, to clean the inner chamber, to regulate the internal temperature of the pizza oven grill 100).
The lid 102 may be physically designed to retain heat, prevent dissipation, and distribute heat throughout the material of the lid 102 to maintain a uniform internal temperature of the lid 102. In one embodiment, the top of the lid 102 may be tilted such that the back of the lid 102 (e.g. the side opposite the opening 112) is lower in height than the front of the lid 102 (e.g. the side incorporating the opening 112). This tilt may be ideal for maintaining an optimal internal environment in the pizza oven grill 100. The tilt achieves this by facilitating naturally-occurring thermal patterns and the flow of convection currents throughout the pizza oven grill 100. Since the opening 112 is in the front of the lid 102, heat rises and exits through the opening 112, but may be blocked by the visor 116. Adjusting the visor 116 to block the opening 112 may prevent heat from exiting the opening 112 whereas adjusting the visor 116 to expose the opening 112 may allow heat to escape.
Referring to
The bricks 224 may be positioned diagonally across the span of the lid 202 (i.e. on one end, the bricks are higher than the bricks on the other end) in order to facilitate air flow around the bricks 224. The lower bricks may receive more direct heat and due to their geometry, there may be laminar flow from the lower bricks to the higher bricks. Though hot air reaching the higher bricks may escape through the front opening, the purpose of the visor is to prevent such escape and provide a variable covering that allows the user of the pizza oven grill to regulate heat flow throughout the pizza oven grill as needed.
Referring to
Referring back to
Heat trapped in this way allows the brick(s) 224 to enter the range of temperatures critical for baking pizzas rapidly and efficiently. In a preferred embodiment, the opening 112 is approximately 65% of the height of the lid 102 to achieve optimal internal convection currents for cooking pizzas. Such an approximation would be understood by a person having ordinary skill in the art (PHOSITA) to be adjustable as needed to optimize heat transfer in pizza oven grills having different physical parameters (e.g. size of lid 102, volume of bowl 104, area of opening 112, area of the opening 112 coverable by visor 116, different heating element 113, different fuel).
An optimal height of the opening 112 may depend on any number of factors, including but not limited to the material of any component of the pizza oven grill 100, the ambient temperature surrounding the pizza oven grill 100, the thickness of the pizza being deposited in the pizza oven grill 100, the atmospheric pressure and humidity, the presence or absence of laminar flow within the pizza oven grill 100, and many other factors. As such, different configurations of the lid 102 (e.g. the differential height across the lid 102, the size of the opening 112, the implementation of the visor 116) may be contemplated and are within the scope of the embodiments described herein.
Referring to
The turntable 334 may be coupled to a driveshaft 340. The driveshaft 340 may be orthogonally coupled to the center of the bottom side (or surface) of the turntable 334 and may extend away from the turntable 334. Referring to
In one embodiment, the driveshaft 340 may have a square profile similar to that of a spit rod used in a typical rotisserie setup, in which the square profile of the driveshaft 340 fits through an aperture of a typical rotisserie motor and is acted upon by the motor to rotate the driveshaft 340. Alternately, the driveshaft 340 may have a triangular profile. In any case, the driveshaft 340 may comprise flat sides and may thus be used with a typical rotisserie motor to be rotated by the motor. In another embodiment, the driveshaft 340 may have a circular profile (or may otherwise have at least one curved side) and may comprise a vertical slit through which a member of the motor may pass. The member may be flush against the sides of the vertical slit and thus, operation of the motor may cause the member to rotate and subsequently cause the driveshaft 340 as well.
Referring to
The driveshaft 440 may extend down through the bowl 404 and through a mounting plate 446 coupled to the underside of the bowl 404. The mounting plate 446 may be welded to the bowl 404 or may be fastened to the bowl 404 by one or more screws 448. Where the driveshaft 440 extends past the underside of the bowl 404, the driveshaft 440 may be wrapped in a heat shield 444 to prevent the driveshaft 440 from conducting enough heat to the components outside of the bowl 404 so as to destroy or render non-functional said components. The heat shield 444 may be made of any insulating material.
The driveshaft 440 may further extend through a motor 450 and into the height adjustment assembly 420. The motor 450 may be suspended above the height adjustment assembly 420 by a bracket 452. The top end of the bracket 452 may be coupled to the underside of the motor 450 and the bottom end of the bracket 452 may be coupled to the bottom plate 418. The bracket 452 may slide into an enclosure of the motor 450, may be welded to the motor 450, or may couple to the motor 450 in other ways. In any case, the bracket 452 is of a sufficient length so as to suspend the motor 450 a distance away from the bowl 404 so as to prevent the internals of the motor 450 from being destroyed by heat emanating from the bowl 404 or heat conducted through the driveshaft 440.
Unlike most rotisserie motors, the motor 450 may allow the driveshaft 440 to extend through the motor 450. As such, the driveshaft 440 may be able to move back and forth through the aperture of the motor 450 and still be rotated by the motor 450. The end of the driveshaft 440 opposite to that coupled to the turntable 434 may sit within the height adjustment assembly 420.
Referring to
The height adjustment assembly 520 may comprise a cover 520a which may cover the components of the height adjustment assembly 520 and protect the components from oils or juices that may drip from the bowl 504 during operation of the pizza oven grill 500. The top of the cover 520a may comprise a receiving end 520b in which the driveshaft 540 may sit and rotate freely. Separating the receiving end 520b from the bottom of the height adjustment assembly 520 may be a solid divider 520c in which the end of the driveshaft 540 may be housed. Underneath the solid divider 520c, the cover 520a may receive an end 520d of a male-threaded rod 520e. The end 520d extrudes from the top of the male-threaded rod 520e. The end 520d extends through a washer-bearing assembly comprising a thrust washer 520f and a thrust washer 520g separated by a thrust bearing 520h. The washer-bearing assembly rests on the portion of the male-threaded rod 520e that surrounds the base of the end 520d. The male-threaded rod 520e may thread through a female insert 520i housed within the bottom plate 518. The bottom end of the male-threaded rod 520e may comprise a handle 520j that may be manually rotated to thread the male-threaded rod 520e through the female insert 520i (i.e. turning the handle 520j clockwise raises the driveshaft 540, turning the handle 520j counter-clockwise lowers the driveshaft 540).
The height adjustment assembly 520 may be a robust means for height adjustment for the pizza oven grill 100. As shown in
The handle 520j may provide a manual means for rotating the male-threaded rod 520e, but in an alternate embodiment, a motor may provide this function. The motor may be coupled to a user interface mounted on the pizza oven grill 500 that may provide controls for operating the motor and subsequently adjust the height of the turntable 334 (e.g. ‘up’ button, ‘down’ button).
The motor 550 may also comprise controls for operation of the motor 550. The motor 550 may also comprise a microcontroller and network interface and may thus be network-enabled (e.g. Bluetooth, WiFi™, etc.) and controllable remotely by a data processing device (e.g. a smartphone or personal computer). Through an app executed by the data processing device, the data processing device may display a number of parameters (e.g. RPM, torque rating, weight) generated by various sensors within the motor 550 or positioned in around other components of the pizza oven grill. The app may also provide a user interface for controlling a set of functions of the motor 550. The motor 550 may derive power from a 110V/220V outlet, a handcrank and dynamo charger, a thermo electric generator module, a Stirling engine, or a photovoltaic panel. Other sources of power (renewable or otherwise) may be used to provide power to the motor 550 and are within the scope of the exemplary embodiments described herein.
Referring to
Though two embodiments of the height adjustment assembly 620 are shown, the height adjustment assembly 620 may be implemented in other ways. Such changes may be contemplated by a PHOSITA and are within the scope of the exemplary embodiments described herein.
Referring to
The column of flame 715 may proceed past the turntable 734 and may apply direct heat to the one or more bricks 724 of the lid 702. The one or more bricks 724 may be insulated by the plate 726 and the pizza stone 736 may be insulated by the turntable 734, causing the pizza oven grill 700 to retain heat between the one or more bricks 724 and the pizza stone 736.
The airspace 730 serves as an insulator for the plate 726 and the bricks 724. This effect is compounded if the exterior and/or interior sides of the lid 702 are coated with an insulator (e.g. an aluminum blanket, a fiberglass blanket or coating, etc.) This is a key safety feature that also contributes to improvements in fuel efficiency.
When the vertical height of the turntable 734 is changed by rotating the handle 720j of the height adjustment assembly 720, the vertical clearance between the pizza stone 736 and the bricks 724 may also change. Changing the vertical clearance between the pizza stone 736 and the bricks 724 may be necessary in order to ensure uniform heating between the top and bottom of a pizza 754. For example, if a user of the pizza oven grill 700 determines that the bottom of the pizza 754 is cooking more rapidly than the top of the pizza 754, the user may raise the turntable 734 to cook the top of the pizza 754 more rapidly and reduce the rate at which the bottom of the pizza 754 cooks.
Referring to
The driveshaft 740 may slide through the motor 750. The square profile of the driveshaft 740 may match the aperture of the motor 750 through which the driveshaft 740 is inserted. As shown in
In one embodiment, rotation of the turntable 734 may be an automated process. For example, one or more high-temperature sensors placed throughout the pizza oven grill 700 may gather temperature readings which may be communicated to a data processing device of the pizza oven grill 700 or to a data processing device external to the pizza oven grill 700 and communicatively coupled to the one or more high-temperature sensors. The processor of the data processing device may aggregate the temperature readings and generate a three-dimensional heat map of the pizza oven grill 700. Based on the heat map, the data processing device may execute, through a processor of the data processing device, one or more instructions stored in a memory of the data processing device, to communicate a control signal to the motor 750 or a motor of the height adjustment assembly 720. The control signal may cause the motor 750 or motor of the height adjustment assembly 720 to turn on, change RPM, apply more/less torque, or execute other functions. Further instructions may be executed to analyze the heat map and determine an optimal RPM of the motor 750 or the motor of the height adjustment assembly 720.
In another embodiment, operation of the visor 716 (not shown in
An optimal internal environment is achieved by vertically positioning the pizza stone 736 such that the pizza 754 on the pizza stone 736 receives enough heat from the bricks 724 (e.g. by radiation) and enough heat from the pizza stone 736 to cook the pizza 754 in 2-5 minutes, similar to a commercial oven. Unlike current systems, the pizza oven grill 700 comprises features that allow for quick and easy adaptation of the pizza oven grill 700 for different environmental condition (e.g. weather, wind, temperature, low/high humidity, low/high altitude and more). Available pizza oven grills or pizza oven grill conversion systems are not only severely limited, but also fail to emulate the internal environment of a pizza oven. These available pizza oven grills either lack the proper controls (for example, they do not support rotation or height adjustment and may not be able to get hot enough to bake pizzas), are difficult to use in a consistent manner, have not been tested for optimal use in different conditions, do not use refractory ceramic bricks or propane, and/or require significant user manipulation of the pizza in order to achieve minimally acceptable cooking results.
Although the present embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments. It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.
The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”
The various devices and modules described herein may be enabled and operated using hardware circuitry (e.g., CMOS based logic circuitry), firmware, software or any combination of hardware, firmware, and software (e.g., embodied in a non-transitory machine-readable medium). For example, the various electrical structure and methods may be embodied using transistors, logic gates, and electrical circuits (e.g., application specific integrated (ASIC) circuitry and/or Digital Signal Processor (DSP) circuitry).
This application claims priority to U.S. Provisional Patent Application Ser. No. 62/298,140, filed Feb. 22, 2016, the entire disclosure of which is hereby expressly incorporated by reference herein.
Number | Name | Date | Kind |
---|---|---|---|
641575 | Boud | Jan 1900 | A |
898527 | Thoits | Sep 1908 | A |
RE13110 | Thoits | May 1910 | E |
1072231 | Howell | Sep 1913 | A |
1404808 | Taylor | Jan 1922 | A |
2019604 | Grieve | Nov 1935 | A |
2072036 | Horsman | Feb 1937 | A |
2641243 | Goss | Jun 1953 | A |
2842116 | Hinderer | Jul 1958 | A |
3131685 | Bergfield | May 1964 | A |
3134320 | Meyer | May 1964 | A |
3299800 | Angelo | Jan 1967 | A |
3313917 | Ditzler et al. | Apr 1967 | A |
3657996 | Thompson | Apr 1972 | A |
3857363 | Ferlito | Dec 1974 | A |
3952721 | Patterson | Apr 1976 | A |
4210072 | Pedrini | Jul 1980 | A |
4332188 | Rhear | Jun 1982 | A |
4378729 | Pierick | Apr 1983 | A |
4384513 | Pierick | May 1983 | A |
4437396 | Plattner et al. | Mar 1984 | A |
4455319 | Clark | Jun 1984 | A |
4467709 | Anstedt | Aug 1984 | A |
4498376 | Carey | Feb 1985 | A |
4656337 | Lastofka et al. | Apr 1987 | A |
4721037 | Blosnich | Jan 1988 | A |
4763639 | Goldsworthy | Aug 1988 | A |
4800865 | Selzer | Jan 1989 | A |
4889103 | Fraioli | Dec 1989 | A |
4962696 | Gillis | Oct 1990 | A |
5039535 | Lang et al. | Aug 1991 | A |
5097753 | Naft | Mar 1992 | A |
D344871 | Keller | Mar 1994 | S |
5315922 | Keller | May 1994 | A |
5365833 | Chen | Oct 1994 | A |
5413033 | Riccio | May 1995 | A |
5490452 | Schlosser et al. | Feb 1996 | A |
5532456 | Smith et al. | Jul 1996 | A |
5586488 | Liu | Dec 1996 | A |
5592871 | Bartlett | Jan 1997 | A |
5768977 | Parris | Jun 1998 | A |
5797386 | Orr | Aug 1998 | A |
5850780 | Mascia et al. | Dec 1998 | A |
5883362 | Pettibone et al. | Mar 1999 | A |
5996572 | Ilagan | Dec 1999 | A |
6011242 | Westerberg | Jan 2000 | A |
6041769 | Llodra, Jr. | Mar 2000 | A |
6054697 | Woodward et al. | Apr 2000 | A |
RE36724 | Westerberg et al. | Jun 2000 | E |
6070572 | Casagrande | Jun 2000 | A |
6125740 | Hedrington et al. | Oct 2000 | A |
6187359 | Zuccarini | Feb 2001 | B1 |
6262396 | Witt et al. | Jul 2001 | B1 |
6354194 | Hedrington et al. | Mar 2002 | B1 |
6384381 | Witt et al. | May 2002 | B2 |
6425388 | Korinchock | Jul 2002 | B1 |
6615819 | Hernandez-Burgos | Sep 2003 | B1 |
6640695 | Stark | Nov 2003 | B2 |
6647865 | Holl | Nov 2003 | B2 |
6782801 | Correa et al. | Aug 2004 | B1 |
6967036 | Hedrington et al. | Nov 2005 | B1 |
7059318 | Cornfield | Jun 2006 | B2 |
7173217 | De'Longhi | Feb 2007 | B2 |
7219663 | Cuomo | May 2007 | B2 |
7686010 | Gustavsen | Mar 2010 | B2 |
D645295 | Klesath | Sep 2011 | S |
8578927 | Gustavsen | Nov 2013 | B2 |
9016191 | Krolick et al. | Apr 2015 | B2 |
20020017290 | Hines | Feb 2002 | A1 |
20020060215 | Allera et al. | May 2002 | A1 |
20020069764 | Cohen | Jun 2002 | A1 |
20030145740 | Stark | Aug 2003 | A1 |
20050034716 | Harbin | Feb 2005 | A1 |
20050039612 | Denny | Feb 2005 | A1 |
20060102167 | Driscoll, Jr. | May 2006 | A1 |
20060191528 | Spangrud | Aug 2006 | A1 |
20090020111 | Immordino | Jan 2009 | A1 |
20090064872 | Zisserson | Mar 2009 | A1 |
20090078246 | Leavens et al. | Mar 2009 | A1 |
20100124596 | Nelson | May 2010 | A1 |
20110049125 | Home | Mar 2011 | A1 |
20110214662 | Contarino | Sep 2011 | A1 |
20120024171 | Estes | Feb 2012 | A1 |
20120164591 | Chadwick et al. | Jun 2012 | A1 |
20140053739 | Safar | Feb 2014 | A1 |
20140130788 | Contarino | Mar 2014 | A1 |
20140287119 | Dahle | Sep 2014 | A1 |
Number | Date | Country |
---|---|---|
345940 | Mar 1931 | GB |
627760 | Aug 1949 | GB |
2013159018 | Oct 2013 | WO |
Number | Date | Country | |
---|---|---|---|
20170238760 A1 | Aug 2017 | US |
Number | Date | Country | |
---|---|---|---|
62298140 | Feb 2016 | US |