This invention relates to the field of indoor/outdoor furniture, including patio or balcony appliances. More particularly, the invention relates to devices that produce a swirling gas flame, such as torches, fireplaces, heaters, table displays, etc.
People have always been fascinated by fire. Its light and energy provide very useful benefits, and its movement and appearance have pleased countless gazers in a variety of settings, from campgrounds to living rooms. The natural movement of fire provides an almost-lifelike appearance, which contributes substantially to its beauty.
Amplifying the movement of flames can generate an even more pleasing look for observers. One such manner of amplification is to swirl the flame. Swirled flames can have an almost helical look.
Present designs of ‘swirling flame’ gas fireplaces (or similar such aesthetic and/or useful features) rely largely on imparting kinetic energy to a gas in order to cause the flame to move in rotary motion. For example, some approaches use an electric fan to rotate air and any flame that is generated. See, e.g., U.S. Pat. No. 7,175,424. Of course, any mechanical or electrical breakdown would cause the flame to stop rotating and would therefore result in the complete loss of any visual, rotary effect.
Another conventional approach is to provide fireplace or torch with a flame situated within a clear, vertical chimney that admits air in a manner to cause the flame to swirl. In other words, the chimney function is merged with that of a plenum or burn chamber. A burner is positioned at the foot of the chimney. To create a moment about the vertical axis within the chimney, such a chimney is commonly square or rectangular with vertical air slots. Typically, the vertical air slot may be positioned consistently along the same vertical (e.g., leading) edge of each of the faces of the chimney. These vertical air slots admit air into the chimney for combustion. When the flame is started, combustion gasses begin to rise within the chimney. This rising flow creates a low pressure that pulls combustion air into the chimney/plenum. Because the air enters the chimney tangentially to the flame or vertical axis, the air will tend to twist the flame.
Although this approach is an improvement over artificial or mechanically created draft devices, it nevertheless presents some difficulties. The use of vertical air slots in the sides of a chimney requires the creation of a moment with respect to a vertical axis. This approach would likely be less effective in chimneys having shapes without edges, such as tubular (i.e., cylindrical) chimneys. Such slots would likely not have a geometric configuration favorable to generating swirling effects because the tangential orientation that creates a twisting moment would be difficult to structure or would be obtrusive/aesthetically unpleasing. Moreover, because the air enters along the combined chimney/plenum or chamber, the burner must be positioned at or near the same level as the slots in order to sustain full combustion at the burner. In other words, a chimney with vertical air slots must have a cross section that accommodates the plenum and burner so that replenishment air can reach the burner, thus limiting the design options available for such chimney. Thus, the burner structure is visible, which may not be desired for an aesthetic device and may require additional screening. Notably, the air slots within the chimney are openings that expose the flame. With an open flame, the level of safety of the apparatus may render it dangerous for use about children or the inattentive. Further, the air flowing into the chimney tends to compress the flame, which necessitates a form of burner gas diverter that redirects the fuel outwardly in order to add volume to the flame. When the swirl rotates away from a portion of the diverter, the flame at the portion will break down small flamelets until the flame rotates back. It is also expected that the entry of combustion air along the course of the chimney is self limiting in that the access for combustion air is at the same point as the combustion, so that it is believed that for a given level of combustion, less of a draft would be created.
Additionally, in some embodiments, gas flow is temporarily deflected in a radial direction by the use of a series of plates. See, e.q., WO 2008/112379 A1. In such embodiments, the upward movement for much of the gas is often completely halted as it impacts the lower plate and moves outward along it. Only after reaching the edge of the plate does the gas resume its upward movement, caused by its natural buoyancy. Hence, in such embodiments, some of the kinetic energy of the gas may not be fully utilized.
Disclosed is a gas fire feature that produces a swirling flame by passive means. Among other things, the fire feature may include a configuration of burner ports and louvers or flaps that complement each other to enhance the swirl pattern of gas exiting the burner ports. The fire of such a feature may be supplied by commercially available liquefied petroleum gas, for example.
The complementary burner ports and louvers or flaps respectively direct the combustible gas and air in an upward and swirling direction. The natural kinetic energy of the gas, provided by the gas source, is directed through the placement and orientation of the burner ports. The heat of the flame naturally draws air through the louvers or flaps, which direct the air in the desired direction. The flame may be maintained in a chimney located above the burner ports and louvers or flaps.
An aspect of the feature is a device that uses a natural draft or flow of air to create a gas flame that swirls about a vertical axis. The device includes a base and a chimney.
An embodiment of the base includes a stand, a plenum, and a burner. The stand may have at least one support member that defines an air passage in fluid communication with the surrounding air. This stand has a stand top that defines an opening that lies within the stand top. The base also has a plenum. This plenum has a plenum top, a plenum base, and at least one side, which together define a plenum chamber having a first effective diameter. The plenum may be mounted on the top of the stand with the plenum base engaging the opening in the top of the stand. The plenum base defines a plurality of louvers or flaps. These louvers or flaps are disposed in the plenum base in a radial direction with respect to the vertical axis. The louvers or flaps define a radial slits and scoops depending from the plenum base along the length of the slits. The louver is defined by a raised portion of the plenum base that contours the ends to remain attached to the base, essentially by stretching the metal at the ends of the louver. A flap is defined by a raised portion of the plenum base in which the ends are not connected to the plenum base and the metal is bent at the junction of the flap and the plenum base. Both the louver or flap configuration define slits that establish fluid communication between the stand opening and the plenum. The plenum top defines an outlet centered on the vertical axis with a second effective diameter. This second effective diameter is no greater than the first effective diameter. The base may also include a nozzle mix gas burner. This burner has a top, a bottom, and at least one side, the burner top, bottom, and at least one side thus define a burner chamber having a third effective diameter. The burner outer surface has with a perimeter. This burner outer surface also defines a plurality burner ports. Each of the burner ports has a central axis along the port, along which gas may flow. The burner ports may be angled so as to direct gas in a desired upward direction and a desired rotary direction with respect to the vertical axis. A gas inlet tube, in fluid communication with the burner chamber, may be connectable to a source of gas fuel to supply the burner. The third effective diameter is less than the first effective diameter and the burner is disposed within a lower portion of the plenum substantially centered on the vertical axis. This may leave a desired portion of the plenum base exposed about the burner. In this exposed area, the plurality of louvers or flaps may be disposed. In addition, the plenum base may further define a passage adapted to receive the gas inlet tube.
As noted above, the device also includes a chimney. An embodiment of the chimney defines a vertical flue with an upper end and a lower end, the chimney having a fourth effective diameter. The lower end of the flue may be operably engaged with the plenum outlet and thereby in fluid communication with the plenum chamber, with the chimney being substantially centered on the vertical axis.
An aspect of this embodiment is that the scoops may be inclined at such an angle, so that when air flows from the stand into the plenum via the louvers or flaps, then the air flow is angled in the same desired rotary direction as the gas.
Optionally, the burner ports and the scoops are oriented to direct gas and air flow in a clockwise direction or, conversely, in a counterclockwise direction.
In one version of the device, the third effective diameter is less than the second effective diameter. In another version, a vertical collar may be disposed about the plenum top outlet. In another version, a piezoelectric starter may be disposed within the plenum chamber and outside of the burner chamber. In another version, the chimney may be comprised of a transparent material.
Various dimensional and shaped alternatives are available. For example, the fourth effective diameter may be greater than the second effective diameter. The fourth effective diameter may be greater than the third effective diameter. In one embodiment, the burner chamber, the plenum chamber, and the chimney are substantially cylindrical and substantially centered about the vertical axis.
There may also be placement variation in the burner ports. For example, the plurality of burner ports may be disposed in the at least one side of the burner, or in the top of the burner.
In one embodiment, the gas burner outer surface defines a plurality of upward projections disposed in a substantially circular manner about the perimeter of the gas burner outer surface. Each of these projections has a rear incline and a front incline. The plurality of burner ports may be defined in the front inclines of the upward projections. In one version of this embodiment, each of the plurality of burner ports may be consistently disposed in substantially the same location relative to each respective vertical projection.
The device may incorporate or integrate various decorative, furnishing arrangements, such as a waterfall, a table, torch, or a torchiere.
In one of these arrangements, the device may further include an integrated waterfall device connected to the base, which forms at least one waterfall surface and defines at least one spillway in an upper end of the waterfall surface. Such a spillway is capable of spilling water along the waterfall surface in desired relation or manner. A water pump may engage with the waterfall device, and can be capable of pumping water from a pump inlet and out a pump discharge. In such an arrangement, the device may provide a water pump reservoir capable of holding water, with the water pump discharge being in fluid communication with the at least one spillway, the water pump reservoir being adapted to receive water spilling along the waterfall surface, and the water pump reservoir being in fluid connection with the water pump inlet.
Optionally, the at least one spillway of the above waterfall arrangement comprises two or more spillways, and the integrated waterfall device further defines a central, somewhat vertical channel interposed vertically between two spillways, and wherein at least a portion of the chimney is positioned within the central channel. In another option, the waterfall surface may define a plurality of somewhat horizontal corrugations.
In a torch or torchiere arrangement, the device may have a base that further includes an integrated casing disposed about at least a portion of the base, the casing having at least one casing support surface for supporting the base without preventing the stand's fluid communication with surrounding air, and one or more legs connected to and depending from the casing, thereby elevating the device in the manner of a torch.
In a table arrangement, the device may include an integrated table having a casing disposed about at least a portion of the base, and adapted to support the base without preventing the stand's fluid communication with surrounding air. Such a table may include a substantially horizontal table top, with the table top defining a horizontal hole positioned in the table top proximate the casing and centered on the vertical axis; at least one leg may depend from and be connected to the table for providing support. In this arrangement, the chimney may be substantially centered on the vertical axis and may pass through the hole in the table top. An optional version of this arrangement may have a table top of a transparent material.
An aspect of an alternative embodiment of the device also includes a base and a chimney.
An embodiment of this base includes a stand, a plenum, and a burner. The stand may have at least one support member that defines an air passage in fluid communication with the surrounding air. This stand has a stand top that defines an opening in the stand top. The base also has a plenum. This plenum has a plenum top, a plenum base, and at least one side, which together defines a plenum chamber having a first effective diameter. The plenum may be mounted on the top of the stand with the plenum base engaging the opening in the top of the stand. The plenum base defines a plurality of louvers or flaps. These louvers or flaps are disposed in the plenum base in a radial direction with respect to the vertical axis. The louvers or flaps define a radial slit and scoops depending from the plenum base along the length of the slits. The slits establish fluid communication between the stand opening and the plenum. The plenum top defines an outlet centered on the vertical axis with a second effective diameter. This second effective diameter is no greater than the first effective diameter. A vertical collar may be disposed about the plenum top outlet. The base may also include a nozzle mix gas burner. This burner has a top, a bottom, and at least one side, the burner top, bottom, and at least one side define a burner chamber having a third effective diameter. The burner has an outer surface with a perimeter. This burner outer surface also defines a plurality burner ports. Each of the burner ports has a central axis along the port, along which gas may flow. The burner ports may be angled so as to direct gas in a desired upward direction and a desired rotary direction with respect to the vertical axis. A gas inlet tube, in fluid communication with the burner chamber, may be connectable to a source of gas fuel to supply the burner. The gas burner outer surface may define a plurality of upward projections disposed in a substantially circular manner about the perimeter of the gas burner outer surface. Each of these projections has a rear incline and a front incline. The plurality of burner ports may be defined in the front inclines of the upward projections. The third effective diameter may be less than the first effective diameter and the second effective diameter. In addition, the burner may be disposed within a lower portion of the plenum, substantially centered on the vertical axis so as to leave a desired portion of the plenum base exposed about the burner. The plurality of louvers or flaps may be disposed within the exposed portion of the plenum base. In addition, the plenum base may further define a passage adapted to receive the gas inlet tube.
As noted above, the device also includes a chimney. An embodiment of the chimney defines a vertical flue with an upper end and a lower end, the chimney having a fourth effective diameter. The lower end of the flue may be operably engaged with the plenum outlet and thereby in fluid communication with the plenum chamber, with the chimney being substantially centered on the vertical axis.
An aspect of this embodiment is that the scoops may be inclined at such an angle, so that when air flows from the stand into the plenum via the louvers or flaps, then the air flow is angled in the same desired rotary direction as the gas.
An aspect of an alternative embodiment of the device also includes a base and a chimney.
An embodiment of this base includes a stand, a plenum, and a burner. The stand may have at least one support member that defines an air passage in fluid communication with surrounding air. This stand has a stand top that defines an opening in the stand top. The base also has a plenum. The plenum has a plenum top, a plenum base, and at least one side, which together defines a plenum chamber having a first effective diameter. The plenum may be mounted on the top of the stand with the plenum base engaging the opening in the top of the stand. The plenum base defines a plurality of louvers or flaps. These louvers or flaps are disposed in the plenum base in a radial direction with respect to the vertical axis. The louvers or flaps define a radial slit and scoops depending from the plenum base along the length of the slits. The slits establish fluid communication between the stand and the plenum. The plenum top defines an outlet centered on the vertical axis with a second effective diameter. This second effective diameter is no greater than the first effective diameter. The base may also include a gas burner. This burner has a top, a bottom, and at least one side, the burner top, bottom, and at least one side define a burner chamber having a third effective diameter. The burner has an outer surface with a perimeter. This burner outer surface also defines a plurality burner ports. Each of the burner ports has a central axis along the port, along which gas may flow. The burner ports may be angled so as to direct gas in a desired upward direction and a desired rotary direction with respect to the vertical axis. A gas inlet tube, in fluid communication with the burner chamber, may be connectable to a source of gas fuel to supply the burner. The gas burner may be disposed within a lower portion of the plenum, substantially centered on the vertical axis so as to leave a desired portion of the plenum base exposed about the burner. The plurality of louvers or flaps may be disposed within the exposed portion of the plenum base. In addition, the plenum base may further define a passage adapted to receive the gas inlet tube.
As noted above, the device also includes a chimney. An embodiment of the chimney defines a vertical flue with an upper end and a lower end, the chimney having a fourth effective diameter. The lower end of the flue may be operably engaged with the plenum outlet and thereby in fluid communication with the plenum chamber, with the chimney being substantially centered on the vertical axis. The fourth effective diameter may be greater than the second and third effective diameters.
Additionally, the scoops may be inclined at such an angle, so that when air flows from the stand into the plenum via the louvers or flaps, the air flow is angled in the same desired rotary direction as the gas.
An aspect of this gas feature is to produce a swirling flame by passive means. By passive, it is meant that the device does not require a power source in order to impart additional kinetic energy to the gas, or to the air mixing with the gas, for the purpose of causing a rotary motion of a swirling flame.
With reference to the figures, and
The burner 140 defines a burner chamber 141 that is in fluid communication with a gas inlet tube 142, for the supply of gas from the supply system into the burner chamber. The gas inlet tube 142 should form a secure fit with both the gas source and the burner chamber 141. An aspect of an embodiment of burner 140 is to be “nozzle mix,” in that gas and air mix after gas exits the burner (i.e., as opposed to pre-mixing the air and the gas prior to exiting the burner); air inlet pilot holes or other sources of air leakage in tube 142 may disadvantageously introduce excess air, depending on the design. A control valve 143 (not shown in
The plenum 130 comprises plenum base 131, one or more sides 132, and a top 133 defining a plenum chamber 134 and plenum outlet 135. Plenum 130 may take a variety of shapes; however, a generally circular plenum chamber 134 (i.e., having a first effective diameter) is believed to enhance swirling airflow, as described further below. The plenum outlet 135 may also be circular and may have a second effective diameter the same, or in order for plenum outlet 135 to form a restriction or nozzle, less than the first effective diameter of the circular plenum chamber 134. A vertical collar 136 may be disposed about the perimeter of the plenum outlet 135.
The term “effective diameter” is a general reference to the approximate diameter of a circle that would have about the same cross sectional area as the cross sectional area in question. Effective diameter may thus refer to the cross sectional area of various portions of the present invention. For example, with respect to a circular embodiment, plenum chamber 134 would have the same (first) effective diameter as the actual diameter. However, a polygonal embodiment of plenum chamber 134, such as a rectangle having sides with lengths L1 and L2, would have an effective diameter De as follows:
The foregoing should be qualified with a general design principle that, for example, plenum chamber 134 is unable to define a plenum outlet 135 with a cross section area that goes beyond the bounds of the cross sectional area of plenum chamber 134; by definition, if it did it would not serve as an ‘outlet’ of plenum chamber 134.
The burner 140 may be disposed within the plenum 130, with ‘disposed’ simply meaning that burner 140 relates to plenum 130 in a manner so as to be able discharge gas into the plenum. Burner chamber 141 may be considered as having a third effective diameter. For embodiments in which burner 140 is disposed within plenum 130 as shown in
Chimney 110 may be considered as having a fourth effective diameter. In some embodiments, the fourth effective diameter may be greater than the second effective diameter. The fourth effective diameter of chimney 110 may also be greater than the third effective diameter of burner chamber 141.
Preferably a starter 145 may be located in the plenum 130. The starter 145 may be conventional, such as a piezoelectric electrode coupled to an actuation system, or simply a manual lighting port in the plenum side for lighting the gas. Any suitable starter may be used.
The plenum base 131 defines a plurality of louvers (or flaps) 137 (for clarity, herein louver 137 defines both a louver or flap configuration) configured to admit air into the plenum 130 for combustion. The chimney 110 may be in the form of a tubular structure mounted about the plenum outlet 135. The chimney 110 may be made of glass or other transparent or translucent material that may sustain the contemplated temperatures. The plenum 130 and burner 140 may be made of metallic materials. For example, stainless steel may be employed for plenum base and burner components to be used outdoors.
The configuration of the burner ports 144 and the louvers 137 may complement each other to enhance the swirl pattern of the gas exiting the burner ports.
For example, in one embodiment (see
Alternatively, ports 144 or teeth 147 with ports 144 may be disposed on the side of burner 140.
In some embodiments, each of the gas ports 144 is located in the same position on its respective burner stepped tooth 147. This commonality of location can improve the movement and appearance of the flame 160 by producing a consistent swirl pattern. In some embodiments, the common position for the burner port 144 is located on the front face of the tooth 147a at or near the intersection of the front face, the back face 147b, and the outer face 147c of the tooth 147. Distributing the ports 144 about the perimeter of the burner 140 in this fashion also improves the mixing of gas with combustion oxygen, which generally exists in greater amounts at the perimeter of a vortex, as opposed to its center, which is typically a low-pressure zone.
An aspect of teeth 147 is to enable better control of the gas flow without the need for a more substantial burner having tubes/nozzles and/or injectors. This may provide both simpler (and less expensive) production of burner 140 and for a more pleasing aesthetic appearance for various flame-generating products. For example, the embodiment shown in the figures involves a burner 140 fabricated of stamped metal components, with burner ports 144 drilled at the desired location. Of course, other fabrication approaches may be used, such as casting, but stamping has been found to be particularly economical. The tubes, nozzles, and/or injectors that are discussed above may also be used with the invention, if desired for the application.
In one embodiment (see
The louvers 137 of the plenum base 131 may be configured to produce a flow of air that matches the clockwise or counterclockwise flow of gas.
In one embodiment, the louvers 137 define radially disposed slits 138 with radially disposed scoops 139 depending from the plenum base 131 along the length of the slits 138. Slits 138 establish fluid communication between plenum 130 and surrounding air via stand 150. The scoops 139 are configured at such an angle to draw air into the plenum 130 in a swirl pattern or rotary direction similar and complementary to the swirl pattern or rotary direction of the gas exiting the burner ports 144. Upon starting a flame 160 (not shown in
Each of the louvers 137 may be disposed in the plenum base 131 in a substantially radial orientation, and may be located substantially between a centrally located gas entry port 131a and the outward edge of the plenum base. (The gas entry port 131a permits the plenum base 131 to be configured in a manner with the burner 140 that allows fluid connection of the gas inlet tube 142 with the burner chamber 141.) An aspect is that louvers 137 may include scoop 139 to facilitate the entry of air along a desired direction through corresponding louver slit 138. The scoops 139 may be straight (i.e., ramping) or may have a curved (i.e., C-shaped) shape. The scoops 139 are configured in a way that creates gaps 137a between the scoops and the plenum base 131 (see
The magnitude of the vertical angle θ1 (see
The magnitude of the horizontal angle θ2 (see
As disclosed, θ2 is the angle as measured from a conventional tangent. There can be some θ2 values that are ‘negative’ with respect to tangent. The normal gas plume dispersion for the primary embodiment would be rather broad or wide and may allow that some portion of the gas would flow somewhat in from a tangent.
These horizontal and vertical angles may be set as desired to achieve various types of rotary or swirling movement for the flame 160. In some embodiments, the vertical angles θ1 for each of the front faces 147a and the ports 144 are the same. In some embodiments, the horizontal angles θ2 for each of the front faces 147a and the ports 144 are the same.
For the low cost, stamped embodiment shown in the figures, ports 144 may be formed by drilling in front faces 147a, thereby creating an orifice. In this configuration, given the typical pressures of commercially available gas supplies, the gas plume generally forms with an arc that is larger than that which might be formed by a more substantial or controlling nozzle. Of course, pressure variations may alter the characteristics of the gas plume as well. However, such arcs may be effectively controlled by the angle of back faces 147b. Back faces 147b may be angled upwardly in a way that assists in directing gas upwardly towards the plenum outlet 135, in a swirling direction. In some embodiments, the vertical angle of the front faces 147a (and corresponding ports 144) is the same or substantially the same as the degree of slope θ3 (measured in degrees above the horizontal plane 102; see
The structures described above can be used in a variety of methods of operation. For example, with particular reference to
(i) Gas enters the burner 140 through the burner gas inlet tube 142 and exits the burner 140 through a plurality of gas ports 144 in the burner 140, shown in this embodiment as being located on burner top 146. The ports 144 may be angled in an upward direction of 0 degrees to 90 degrees from the horizontal plane. This may be considered the step of providing a burner 140 and plenum 130, admitting a combustible gas into the plenum through a plurality of angled gas ports 144 in the burner 140, and inducing an angled flow in the gas. The ports 144 may be angled from 0-90 degrees from the radial in combination or separate from 0-90 degrees from the vertical plane.
(ii) Combustion air enters the plenum 130 through a plurality of louvers 137, optionally arranged in a substantially radial pattern in the plenum base or “swirl plate” 131. The burner ports 144 and louvers 137 (i.e., including scoop 138 orientation and angle) may be directed to producing either a clockwise or counterclockwise rotary direction (as viewed from above). This may be considered the step of providing air or oxygen through a plurality of angled louvers 137 consistent or complementary to the plurality of angled ports 144.
(iii) The plenum outlet 135 may have a reduced cross section to increase the velocity of air and gas, and to impart a very tight swirl to the flame 160 (see
(iv) In operation, the flame 160 increases in height as the optionally glass chimney 110 heats up, further inducing a draft. Heat resistant polymers or other suitable materials may also be used as materials of construction for chimney 110, so long as they are selected or matched to be appropriate for the contemplated temperatures. A blower is not required to produce the swirling flame 160. This may be considered the preliminary step of providing a chimney 110 operatively engaged with the plenum outlet 135.
The many available embodiments permit a broad range of applications. For example, the gas feature may include the structure of a decorative or useful torch or touchier, possibly having a gas container that is smaller than the conventional 4.73-gallon tank. It is contemplated that the present invention may include an integrated table, such as being inset into a variety of table styles with, in some embodiments, having a chimney that passes through a hole in the table top. In another embodiment, a coffee table may have open or transparent elements, such as a transparent chimney and table top, by which the swirling flame may be viewed. Of course, such an application may be available for balcony tables, side tables, dining tables, etc. The gas feature may be provided as stand alone embodiments as well, such as sconces, fireplaces, braziers, or lamps. One embodiment, for example, may be a decorative table top design. Another embodiment may be a fireplace of such a scale as to provide useful warming of the surrounding area.
In one embodiment, shown in
The water may thus fall or flow from spillway 210 into a receptacle, such as water pump reservoir 240 (
Light generated by flame 160 can thus reflect from the cascading water in a pleasing way.
In other embodiments, shown in
In another embodiment, shown in
In other embodiments, shown in
In this example, an embodiment of the invention was made using steel, preferably stainless steel for some external applications, to construct the housing, plenum, and gas burner. Eight louvers having lengths of 4.8 centimeters and widths of 1.36 centimeters were machined into the plenum base, with each louver having an angled scoop creating a gap of about 5.3 millimeters between the scoop and the plenum base. A transparent chimney was employed in order to facilitate viewing of the flame created by the device.
The gas burner included stepped teeth, similar to those shown in
Similar efforts lacking either a chimney or the louvers produced a flame with little or no swirling effect, just a straight coalescing flame.
It is to be understood that the invention is not to be limited to the exact configuration as illustrated and described herein. Accordingly, all expedient modifications readily attainable by one of ordinary skill in the art from the disclosure set forth herein, or by routine experimentation therefrom, are deemed to be within the spirit and scope of the invention as defined herein. For example, although several device components in the exemplified embodiments are shown as circular, other shapes, such as rectangular and square, may also be used.
The present application claims the benefit of priority from U.S. Provisional Application Ser. No. 61/203,550, filed Dec. 24, 2008, which is incorporated by reference.
Number | Date | Country | |
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61203550 | Dec 2008 | US |