Patent Application
20170136472
This invention relates to fluid handling processes and apparatus. More particularly, this invention relates to a fluidic oscillator and method for use in generating precisely controlled sprays at colder temperatures usually associated with higher viscosity fluids.
Fluidic oscillators are well known in the prior art for their ability to provide a wide range of liquid spray patterns by cyclically deflecting a liquid jet. The operation of most fluidic oscillators is characterized by the cyclic deflection of a fluid jet without the use of mechanical moving parts. Consequently, an advantage of fluidic oscillators is that they are not subject to the wear and tear which adversely affects the reliability and operation of other spray devices.
Examples of fluidic oscillators may be found in many patents, including U.S. Pat. No. 3,185,166 (Horton & Bowles), U.S. Pat. No. 3,563,462 (Bauer), U.S. Pat. No. 4,052,002 (Stouffer & Bray), U.S. Pat. No. 4,151,955 (Stouffer), U.S. Pat. No. 4,157,161 (Bauer), U.S. Pat. No. 4,231,519 (Stouffer), which was reissued as RE 33,158, U.S. Pat. No. 4,508,267 (Stouffer), U.S. Pat. No. 5,035,361 (Stouffer), U.S. Pat. No. 5,213,269 (Srinath), U.S. Pat. No. 5,971,301 (Stouffer), U.S. Pat. No. 6,186,409 (Srinath) and U.S. Pat. No. 6,253,782 (Raghu). An oscillating liquid jet can yield a variety of spray patterns for the downstream distribution of the liquid droplets that are faulted as this liquid jet breaks apart in the surrounding gaseous environment.
For the spraying of some high viscosity liquids (i.e., 15-20 centipoise), the “mushroom oscillator” disclosed in commonly owned U.S. Pat. No. 6,253,782 was found to be especially useful. However, it also has been found that, as the temperature of such liquids continues to decrease so as to cause their viscosity to increase (e.g., 25 centipoise), the performance of this type of oscillator can deteriorate to the point where it no longer provides a jet that is sufficiently oscillatory in nature to allow its spray to be distributed over an appreciable fan angle. This situation is especially problematic in automotive windshield washer applications.
An early approach to solving that problem by the instant applicant led to the method and structure of the “Three Jet Island” fluidic circuit of commonly owned U.S. Pat. No. 4,761,036, as illustrated in
There is a need, therefore, for an improved method and apparatus for generating sprays of colder, more viscous fluids.
Accordingly, it is an object of the present invention to overcome the above mentioned difficulties by providing a durable, reliable and cost effective nozzle structure, fluidic oscillator structure and fluid distribution or spray generation method to enhance the reliable initiation and maintenance of an oscillating spray and broaden the dynamic and cold performance envelope for nozzle assemblies to be used in automotive and other applications.
Another object of the present invention is to provide a fluidic nozzle and oscillator circuit having improved reliably when fluid flow begins to induce the fluid dynamic mechanisms within the interaction chamber to quickly establish and maintain the desired oscillating spray, especially with cold or viscous fluids.
In accordance with an illustrative embodiment of the present invention, a fluidic circuit is configured as a nozzle assembly with a fluidic oscillator. Fluidic oscillators or fluidic circuits are often configured for use in housings which define a channel, port or slot that receives and provides boundaries for the fluid paths defined in the fluidic circuit. For an illustrative example of how a fluidic oscillator or fluidic circuit might be employed, as shown in applicant's U.S. Pat. No. 7,651,036,
A nozzle assembly can be configured to include one or more fluidic circuit inserts or chips which are dimensioned to be tightly received in and held by the slot defined within the sidewall of the housing. When the fluidic circuit insert is fitted tightly within the housing's port or slot, the nozzle assembly provides a channel for fluid communication between the housing's interior lumen and the exterior of the housing so that fluid entering the housing's interior lumen may be used to generate an oscillating spray directed distally and aimed by the orientation and configuration of the housing.
The new fluidic circuit geometries of the present invention operates on a new and surprisingly robust oscillation inducing and maintenance mechanism which provides reliable formation of moving vortices that generate a repeatable oscillating jet stream and subsequent spray. Current prototypes of the circuit of the present invention produce a planar spray with a fan angles from 20° to 120°. A first embodiment of the fluidic circuit of the present invention has a plurality of sections which cooperate with one another to act upon the flowing fluid passing therethrough to generate internal vortices and a desired oscillating spray. In sequence, pressurized fluid initially flows into an inlet which passes through an optional filtering section and then into a fluid flow dividing three-way power nozzle section, where fluid is passed into and through first, second and third power nozzles which are configured generate and aim first, second and third fluid jets into a vortex generating interaction chamber or cavity section where the three jets collide with one another and with internal features to initiate and maintain distally moving fluid vortices. The interaction chamber or cavity section terminates distally in a throat or outlet orifice configured to distally project the oscillating spray into the ambient environment.
In accordance with the present invention, an improved nozzle assembly includes at least one fluidic oscillator which operates on pressurized fluid flowing therethrough to generate and aim that oscillating spray of fluid droplets. The fluidic oscillator's internal geometry aims the fluid jets from the first, second and third power nozzles into the interaction chamber and against an upwardly projecting island protuberance defining first, second and third island wall segments. The island protuberance is spaced from but aligned along a common central axis with the outlet orifice at the distal or spray end of the interaction chamber and the interaction chamber defines an interaction region having an interaction region width, Iw in the range of 12.5-13.5 times the Power Nozzle Width, Pw (preferably 13 Pw). The interaction region has an axial length or height, II in the range of 7.5-8.5 Pw and the first and third (outermost) jets intersect downstream at a selected jet intersection point, JI, which is distally spaced from the central or second orifice by a distance equal to 2.5-3 Pw. The first and second (outermost) jets are aimed and aligned along first and second jet axes which intersect at a selected obtuse Jet intersection angle, JA which is preferably approximately 110 degrees.
In the fluidic geometry of the present invention, the first, second and third orifices are defined between (a) the interaction chamber's opposing left and right side walls and (b) first and second curved, transverse fluid impermeable wall segments, where the first curved, transverse wall segment provides a first concave wall surface defining a first cylindrical wall section of a selected radius and the second curved, transverse wall segment provides a second concave wall surface defining a second cylindrical wall section of a second selected radius which is substantially equal to said first concave wall surface's selected radius. The first and second concave wall surfaces define laterally offset cylindrical wall sections configured to receive and contain laterally offset fluid vortices which are formed, grow and move about within the interaction chamber.
The first, second and third jets cause vortices to form and move about within the interaction chamber in a bistable periodic oscillation cycle. The bistable oscillation cycle is initiated when the center jet alternates on each side of the interaction chamber's upwardly or inwardly projecting island and that center jet alternately sheds or generates laterally spaced (e.g., left and right side) vortices. Initially the center jet is on one side of the island (e.g., the left side) resulting in a large vortex on that (e.g., the left) side. This left side vortex partially blocks or suppresses the left side jet flowing from the left side orifice, resulting in (a) initiation of a right side vortex upstream of the island and proximate the right side orifice and (b) the right jet dominating the output jet exiting the outlet orifice or throat lumen, thereby defining the left extreme end or edge of the fluidic's spray fan. In time, the left side vortex and right side vortex both move distally and the center jet begins to move towards the opposing (e.g., right) side of the island.
During this transitory phase, the output jet is passing through the center of the spray fan issuing from throat lumen. When the center jet moves laterally to the right side of the island, the output jet spray is aimed at its right extreme of the fan. This oscillation cycle repeats itself at relatively high frequency (e.g., as high as 300 Hz depending on size and operating pressures/flow rates).
In order to ensure that the oscillation is (a) reliably begun and (b) the fluid jet oscillation steering mechanism is reliably maintained within the interaction chamber, especially with cold or viscous fluids, another embodiment having a T-shaped island was refined. The fluidic circuit embodiment with the T-shaped island has a proximally projecting wall segment which provides especially robust oscillation initiation over a very broad range of fluid temperature and viscosity conditions.
Background
In accordance with the present invention, a nozzle assembly is configured to include one or more fluidic circuit inserts or chips (e.g., 100, 200 or 300) which are dimensioned to be tightly received in and held by the cavity or slot defined within the sidewall of the housing. When the fluidic circuit insert (e.g., 100, 200 or 300) is fitted tightly within the housing's cavity or slot (e.g., 20), the nozzle assembly provides a channel for fluid communication between the housing's interior lumen (which provides a fluid inlet for pressurized fluid) and the exterior of the housing so that fluid entering the housing's interior lumen may be used to generate an oscillating spray directed distally and aimed by the orientation and configuration of the housing.
The nozzle assembly's head (e.g., similar to 10, as illustrated in
The fluidic insert or chip (e.g., 100, 200, or 300, as will be described in greater detail, below) is a generally flat member adapted to be forced or pressed into the housing's cavity 20 and securely retained therein by the pressure exerted by the housing cavity walls on the insert. For this purpose the material from which the housing is fabricated is a solid plastic which deforms slightly under pressure. The cavity has a top wall and bottom wall which are spaced by a distance substantially equal to the thickness of the insert (e.g., 100, 200, or 300) between the insert top surface and bottom surface. Optionally, the bottom surface may somewhat bowed, making the insert somewhat thicker along its middle. The insert's sidewalls are likewise spaced by a distance substantially equal to the width of insert between its left and right side or lateral edges. In a preferred embodiment, the fluidic circuit insert (e.g., 100, 200, or 300) may be a few thousandths of an inch wider than the nozzle head's cavity 20. The insert (e.g., 100, 200, or 300) and cavity 20 may taper along their axial lengths, being wider at the exposed distal end and narrowing toward the inserted proximal end. The taper may be gradual or may be effected in one or more discrete sections (e.g., as shown in
The fluidic oscillator is defined in the insert (e.g., 100, 200, or 300) as a plurality of recessed portions in the top surface of a substrate which define fluid passages. All of the fluidic's features are defined as recesses or troughs of equal or varying depths into the top surface of the insert or chip. When the fluidic insert (e.g., 100, 200, or 300) is fully inserted into the housing's slot or cavity, the housing's internal lumen defines an opening into the cavity, and that opening aligns with and communicates with the insert's inlet, so that washer fluid or water flowing into the housing inlet (e.g., 16) flows into the fluidic's interaction chamber (e.g., 118, 218, or 318) to generate oscillating vortices therein, so that an oscillation is established and a jet of fluid is swept back and forth to generate the desired spray 130 which issues through the exit orifice (e.g., 120, 220, or 320). When the selected fluidic insert (e.g., 100, 200, or 300) is pressed or forced into the nozzle head's cavity 20, the cavity's sidewalls 22 are spread slightly and in turn exert a higher pressure along the middle of the insert. The oscillator formed in top surface of the insert (e.g., 100, 200, or 300) is substantially centered between edges of the insert and is very tightly sealed against interior walls of the cavity so that a fluidic oscillator formed in a surface of the insert, or in a surface of the cavity, can be sealed solely by the pressure exerted by the forced fit engagement.
It should be noted that the nozzle head's cavity and fluidic insert (e.g., 100, 200, or 300), although shown as substantially planar, may be arcuate, angled, or otherwise configured, depending upon the shape of nozzle head and spray pattern (e.g., 130) desired. Likewise, oscillator channels may be defined in both the top and bottom surfaces of the insert or in the top and bottom walls of the cavity. The only limitation is that the fluidic oscillator, whichever surface or surfaces it is defined in, is sealed by the abutting surface(s) through the pressure exerted by the force fit within the housing's cavity.
In accordance with a first embodiment of the present invention as illustrated in
The first embodiment of the fluidic circuit of the present invention 100 as illustrated in
Referring again to
As best seen in
The applicants have discovered that by appropriately pressuring, orienting and scaling these elements, one is able to generate improved flow vortices which travel distally behind or downstream of island 126 in a manner that permits those vortices to be swept out of the throat in a more uniform manner such that the vortices are alternately proximate the throat's right sidewall and then its left sidewall. An improved triangular shape and position have been selected as a preferred embodiment for island 126. Substantially triangular island 126 is oriented so that one of its points faces the oncoming flow of fluid jet J3 from the center power nozzle 114C, as best seen in
In fluidic oscillator circuit 100, the first, second and third orifices 114A, 114B and 114C are defined between the interaction chamber's opposing left and right side walls and first and second curved, transverse fluid impermeable wall segments 140, 150, where the first curved, transverse wall segment 140 provides a first concave wall surface 142 defining a first cylindrical wall section of a selected radius and the second curved transverse wall segment 150 provides a second concave wall surface 152 defining a second cylindrical wall section of a second selected radius which is substantially equal to said first concave wall surface's selected radius. The first and second concave wall surfaces 142, 152 define laterally offset cylindrical wall sections configured to receive and contain laterally offset fluid vortices (see, e.g.,
The three fluid jets J1, J2, J3 cause vortices to form and move about within interaction chamber 118 in a bistable periodic oscillation cycle illustrated sequentially in
During this transitory phase (illustrated in
The first, second and third jets J1, J2, J3 cause the vortices to form and move laterally and distally within the interaction chamber 118 in a bistable periodic oscillation cycle which is initiated when center jet J3 begins alternating on left and right (or laterally opposing) sides of the upwardly projecting island 126 which causes center jet J3 to alternately shed or generate the distally moving laterally spaced (e.g., left and right side) vortices. As a result of this oscillation inducing method, enhanced three jet island fluidic circuit 100 generates improved sprays with cold, viscous fluids and a more uniform spray pattern within a given nozzle assembly's spray fan angle. The spray performance is illustrated as the plotted solid line in
In accordance with the method of the present invention, there are at least two distinct, non-obvious and surprisingly effective configurations for the improved three jet island's power nozzles 114A, 114B and 114C:
A) For a substantially uniform spray pattern, all three power nozzles 114A, 114B and 114C are substantially equal in lumen area (e.g., rectangular cross sectional area width and depth). This results in a uniform spray distribution over the spray fan (as illustrated in
B) Alternatively, for a heavy-ended spray pattern, the lumen areas of side power nozzles (similar to 114A, 114B) are equal and slightly larger than the center power nozzle (larger than 114C) (e.g., where the Depth of all three power nozzles is equal). This results in a slightly more fluid at the edges of the spray fan (as illustrated with the dotted line plot of
As noted above, jet intersection angle JA , as shown in
The fluid spray performance improvements obtained with the new geometry illustrated in
As best seen in
In fluidic oscillator circuit 100, the first, second and third orifices 114A, 114B and 114C shown to be defined between the interaction chamber's opposing left and right side walls and first and second curved, transverse fluid impermeable wall segments 140, 150, where the first curved, transverse wall segment 140 provides a first concave wall surface 142 defining a first cylindrical wall section of a selected radius and the second curved transverse wall segment 150 provides a second concave wall surface 152 defining a second cylindrical wall section of a second selected radius which is substantially equal to said first concave wall surface's selected radius. The first and second concave wall surfaces 142, 152 define laterally offset cylindrical wall sections configured to receive and contain laterally offset fluid vortices (see, e.g.,
Turning now to the particulars for the embodiment illustrated in
Improved three jet island fluidic circuit 100, when configured as illustrated in
In the illustrated example, for a 60 degree fan, the throat area is 60% of the power nozzle area. In contrast, in case of applicant's prior patented mushroom circuit, throat area is 100% of the power nozzle area for the same fan angle. Hence, for fluidic circuit 100, pressure losses leading to the throat 120 are lower, which makes a higher spray velocity possible. The higher spray velocity demonstrated is a significant improvement for better dynamic performance (spray performance against wind speed as seen in automotive applications), compared with prior art nozzles.
Island location, island width, Jet angle (JA) of 110 degrees and the larger vortex formation area (available for vortices upstream of the island) allow the fluidic 100 to begin oscillating (or “start”) at a lower fluid pressure with high viscosity liquids. In a washing fluid solution of methanol and water at 50-50 composition, a nozzle spray pattern with a full fan angle (e.g., 60 degrees) is achieved at 3 psi and above. Applicants also found improved cold performance for smaller values of island width. It is a combination of these features that provide better cold performance than earlier embodiments.
Turning now to
Returning to
Broadly speaking, the method for controlling fluids in the three jet bistable oscillator 100 of the present invention requires a fluidic oscillator (e.g., 100, 200 or 300 (described below) operating on a pressurized fluid flowing therethrough to generate an exhaust flow in the form of an oscillating spray of fluid droplets (e.g., 130, 330), where the oscillator includes: an inlet (e.g., filling region 112 which may optionally include an array of filter posts 122) for the pressurized fluid, which then flows into first, second and third power nozzles 114A, 114B, 114C, each having a floor and sidewalls that are configured to define a venturi-shaped tapered lumen to accelerate the movement of that pressurized fluid to form first, second and third jets of fluid that flow from each said power nozzle, where each power nozzle's resulting jet is aligned along a selected jet-flow axis. The fluidic oscillator defines a fluid communication pathway that connects and allows for the flow of the fluid between the inlet 112 and the first, second and third power nozzles, and that fluid communication pathway has a boundary surface that includes a pair of sidewalls to define an interaction chamber 118 which is in fluid communication with the first, second and third power nozzles and which receives first, second and third jet flows from the first, second and third power nozzles. Interaction chamber 118 has a floor, an outlet orifice 120 from which the oscillating spray exhausts, and an upwardly or inwardly projecting island protuberance 126 defining first, second and third island wall segments projecting upwardly from the floor of chamber 118 and placed at an intersection of the jet-flow axes such that island 126 is impacted by the first, second and third jets from the first, second and third power nozzles (as seen in
Two additional embodiments are illustrated in
Interaction chamber 218 has a selected width IW and terminates distally or downstream at a centered outlet lumen or throat orifice 220 from which an oscillating spray exhausts and is defined between right side and left side sidewalls that diverge downstream. Throat orifice 220 is nominally symmetrically defined around the centerline and defines a rectangular lumen having a selected transverse Throat Width TW. Tee-Island 226 is located directly downstream of central power nozzle 214C that is located on the centerline of the interaction chamber 218 and has a selected transverse Island Width IW. Each Power Nozzle generates a flow along a selected power nozzle flow axis having a selected flow axis angle and has a selected Power nozzle Width PW which generates a jet centered initially along the selected power nozzle flow axis. The first and second laterally spaced power nozzles 214A, 214B generate first and second fluid jets which intersect in the interaction region downstream or distally of the island 226 at a Jet intersection point JL and at a selected Jet intersection Angle, JA.
In fluidic oscillator circuit 200, the first, second and third orifices 214A, 214B and 214C shown to be defined between the interaction chamber's opposing left and right side walls and first and second curved, transverse fluid impermeable wall segments 240, 250, where the first curved, transverse wall segment 240 provides a first concave wall surface 242 defining a first cylindrical wall section of a selected radius and the second curved transverse wall segment 250 provides a second concave wall surface 252 defining a second cylindrical wall section of a second selected radius which is substantially equal to said first concave wall surface's selected radius. The first and second concave wall surfaces 242, 252 define laterally offset cylindrical wall sections configured to receive and contain laterally offset fluid vortices which are formed, grow and move about within the interaction chamber 218.
As with fluidic circuit 100, above, the applicants have discovered that by appropriately pressuring, orienting and scaling the fluidic circuit elements of oscillator 200, one is able to generate improved flow vortices before and behind island 226 that are swept out of the throat in a more uniform manner such that the vortices are alternately proximate the throat's right sidewall and then its left sidewall. The tee-island shape and position have been selected as a preferred embodiment for island 226. Tee-island island 226 is oriented so that one of its points faces the distally flowing oncoming fluid from the center power nozzle 214C which are aligned along central axis 202, as best seen in
Turning next to
Interaction chamber 318 has a selected width IW and terminates distally or downstream at a centered outlet lumen or throat orifice 320 from which an oscillating spray exhausts and is defined between right side and left side sidewalls that diverge downstream. Throat orifice 320 is nominally symmetrically defined around the centerline and defines a rectangular lumen having a selected transverse Throat Width TW. Tee-Island 326 is located directly downstream of central power nozzle 314C that is located on the centerline of the interaction chamber 318 and has a selected transverse Island Width IW. Each Power Nozzle generates a flow along a selected power nozzle flow axis having a selected flow axis angle and has a selected Power nozzle Width PW which generates a jet centered initially along the selected power nozzle flow axis. The first and second laterally spaced power nozzles 314A, 314B generate first and second fluid jets which intersect in the interaction region downstream or distally of the island 326 at a Jet intersection point JL and at a selected Jet intersection Angle, JA. The fluidic oscillator geometries illustrated in
In fluidic oscillator circuit 300, the first, second and third orifices 314A, 314B and 314C shown to be defined between the interaction chamber's opposing left and right side walls and first and second curved, transverse fluid impermeable wall segments 340, 350, (e.g., as shown in
Turning now to
The main feature for fluidic embodiments 200 and 300 of
For high viscosity liquids, because of the reduced Reynolds number, there is a strong tendency for the flow to be symmetric, resulting in straight stream as the output (no oscillating jet) as shown in
In accordance with the method of the present invention, there are at least two distinct and surprisingly effective configurations for the Tee island's power nozzles 314A, 314B and 314C:
In prior art oscillators and even with some early prototypes of the present invention (e.g., with triangular island 126, as illustrated in
The newer embodiments of the present invention solve this problem by providing (e.g., in Tee-Islands 226, 326) first and second L-shaped island wall segments or inside corner shaped pockets configured to receive flow from center jet (“J3”) and, in response, create first and second very small counter-rotating island-pocket vortices IVCCW and IVCW (see, e.g.,
The pressurized fluid flow pressure required to force initiation of oscillation in Tee-Island fluidic oscillator 300 is called the “switching pressure” and, as mentioned earlier, the switching pressure for oscillator 300 is less than 17 PSI, which is a significant improvement over the switching pressure required for the prior art and even over earlier prototypes (e.g., 100 as shown in
Other characteristics for Tee-Island Fluidic Oscillators 200 and 300 are similar to those described above for the Improved Three Jet Island Fluidic Oscillator 100. Particularly,
The Interaction region width, Iw: Applicants found optimum values in the range of 12.5-13.5 times the Power Nozzle Width, Pw (preferably 13 Pw);
Interaction region height, Il: This is a critical dimension and varies between 7.5-8.5 Pw;
Jet intersection point, Jl: This is a critical dimension and varies from 2.5-3 Pw;
Jet intersection angle, JA: As mentioned above optimum performance is achieved when the jet-flow axes for the outer-most jets JA is in the range of 100 degrees to 140 degrees, and is preferably around 110 degrees (as seen in
Improved spray velocity: Circuit 300 is capable of spray velocity of approximately 14 m/s. This is enabled because of the specialized geometry leading to a smaller throat area to power nozzle area ratio for a given fan angle.
It will be appreciated that makes an improved nozzle assembly and an improved fluidic oscillator circuit (e.g., 100, 200, 300) available which operates on a pressurized fluid to generate an oscillating spray of fluid droplets, and the oscillator aims fluid jets from first, second and third power nozzles (e.g., 114A, 114B, 114C) into an interaction chamber (e.g., 118) and toward an upwardly projecting island protuberance (e.g., 126) defining first, second and third island wall segments. Each power nozzle has a selected rectangular lumen area and width (“PW”). The island is spaced from and aligned along a common axis (e.g., 102) with an outlet orifice (e.g., 120) at the distal end of interaction chamber which defines an interaction region having an axial length, Il in the range of 7.5-8.5 Pw. The outermost jets (e.g., 114A, 114B) are aimed at an obtuse angle of 100-140 degrees along axes which intersect beyond the island at a Jet intersection point, Jl which is spaced from the orifice by a distance equal to 2.5-3 Pw. The upstream end of interaction chamber is defined by first and second laterally offset concave wall bowl-shaped surfaces (e.g., 142, 152) which define left side and right side vortex generating areas so that fluid jet steering vortices may be alternately formed and then displaced distally to steer the fluid jet laterally within interaction chamber as fluid is pumped through and thereby reliably create and maintain a laterally oscillating spray fan which projects from the outlet orifice into a spray (e.g., 130, 230, 330) having a selected fan angle in the range of 20-120 degrees with the improved spray velocity described above.
Having described preferred embodiments of new and improved nozzle configurations and methods, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as set forth in the appended claims.
This application is a continuation of International Application No. PCT/US2015/040288, filed on Jul. 14, 2015, which claims the benefit of U.S. Provisional Application No. 62/024,762, filed on Jul. 15, 2014, and U.S. Provisional Application No. 62/155,826, filed on May 1, 2015 This application is also related to commonly owned U.S. Pat. Nos. 7,267,290, 7,472,848 and 7,651,036, the entire contents of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62155826 | May 2015 | US | |
| 62024762 | Jul 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2015/040288 | Jul 2015 | US |
| Child | 15406702 | US |
