The present disclosure relates generally to gear-based power-transmitting systems. More particularly, the present disclosure relates to modular gearbox assemblies, including both reduction gearboxes and multiplier gearboxes, modular gearbox kits, methods of manufacturing a modular gearbox assembly, and methods of using a modular gearbox assembly.
Gear-based power-transmitting systems are used in numerous applications to manipulate the power output of a driving mechanism, such as the rotational speed and torque of an electric motor, and transmit that manipulated output to a driven mechanism, such as an HVAC compressor or a pump. Conventional motorized vehicles, such as the modern day automobile, for example, include a powertrain that is comprised of an internal combustion engine (ICE) and/or one or more electric motor/generators in power flow communication with a final drive system (e.g., rear differential and wheels) via a multi-speed power transmission. The primary function of the multi-speed power transmission is to regulate speed and torque to meet demands for vehicle speed and acceleration
Another well-known type of gear-based power-transmitting system is the gear reducer which, in its simplest form, is a mechanical device by which the speed and/or torque output of a driving mechanism is reduced. Gear reducers—also commonly referred to as “gearboxes” or “reduction gearboxes”—accomplish the aforementioned reduction in speed/torque by changing the ratio of rotation between two moving, interconnected parts. Many gear reducers employ a number of gear elements, such as epicyclic planetary gear sets, for coupling the gearbox assembly's input and output shafts. The torque ratio (or “mechanical advantage”) and speed ratio offered by any given gearbox is directly correlated to the number of teeth on each of the gears in the gear train.
In today's market, most commercially available motor-driven gear reducers and gearboxes are custom-made to fit each customer's specifications. For example, a customer will typically have a motor with specific dimensions, distinct output capabilities, a particular output shaft configuration, and application-specific performance requirements. As such, the customer is normally required to engineer or purchase a custom-made gearbox assembly to meet the individual characteristics of their motor and intended application of their powertrain assembly. This results in additional research and development (R&D) and increased manufacturing time, which leads to increased overhead costs and delayed time to market.
According to aspects of the present disclosure, a motor-independent modular gearbox assembly is provided (as used herein, “gearbox” can refer to both reduction gearboxes and multiplier gearboxes). The modular gearbox assembly includes interchangeable planetary-gear inserts (or “gear modules”) that can be selected and arranged to meet the performance specifications of any motor manufacturer. The outer housing is designed to stow and couple with any assortment of these interchangeable inserts, e.g., to provide an endless variety of speed and torque ratios. In addition, the outer housing can be designed to stow and couple with any number of interchangeable inserts, e.g., to offer 1-stage gearboxes, 2-stage gearboxes, 3-stage gearboxes, etc. The modular gearbox assembly can include a flexible beam coupler which allows the gearbox to operatively couple to the output shaft of any motor assembly.
These features offer significant flexibility to use the disclosed gearbox designs for a variety of applications and with a variety of motors. Notable advantages of some of the disclosed concepts include reduced engineering time and costs to research and develop a desired gearbox assembly, as well as decreased manufacturing and assembly time and costs for fabricating the desired gearbox assembly, all of which lead to reduced overhead costs and faster time to market. Other advantages include simplicity of assembly, use and repair, increased flexibility and scalability, and reduced repair times and warranty costs.
Aspects of the present disclosure are directed to a modular gearbox assembly for transmitting the power output of a driving mechanism to a driven mechanism. The modular gearbox assembly includes one or more gear modules, each of which comprises a gear train encased by a module housing. The gear train of each gear module includes a plurality of intermeshed gear elements that cooperatively provide a predetermined gear ratio. The module has an outer periphery with one or more coupling elements projecting radially outward therefrom. The modular gearbox assembly also includes a gearbox housing that stows therein the one or more gear modules. The gearbox housing has an input coupler configured to attach to the driving mechanism and transmit the power output therefrom to the gear module(s) such that the power output is modified by the gear module(s). The gearbox housing also has an output coupler configured to attach to the driven mechanism and transmit thereto the modified power output from the gear module(s). The gearbox housing has an inner surface with one or more protrusions projecting radially inward therefrom. The one or more protrusions of the gearbox housing mate with the one or more coupling elements of the module housing(s) to thereby retain the one or more gear modules inside the gearbox housing.
In accordance with other aspects of the present disclosure, a kit is featured for assembling a gearbox assembly operable to receive, modify and transmit the power output of a driving mechanism, such as an electric motor. The kit includes a plurality of self-contained gear modules, each of which comprises a gear train encased by a module housing. The gear train, which may be in the nature of a planetary gear set, includes two or more intermeshed gear elements that cooperatively provide a predetermined gear ratio. The module housing has one or more coupling elements projecting radially outward therefrom. The kit also includes a gearbox housing configured to stow therein any one or more of the self-contained gear modules. The gearbox housing has an input coupler for attaching to the driving mechanism and transmit the power output therefrom to the one or more gear modules such that the power output is modified by the gear module(s). The gearbox housing also has an output coupler for outputting from the gearbox housing the modified power output. The gearbox housing has an inner surface with one or more protrusions projecting radially inward therefrom. The one or more protrusions of the gearbox housing are configured to mate with the one or more coupling elements of the module housing(s) to thereby retain the one or more gear modules inside the gearbox housing.
Other aspects of the present disclosure are directed to a method for assembling a gearbox assembly operable to receive power output from a driving mechanism, modify the power output, and transmit the modified power output to a driven mechanism. The method includes: identifying a desired gearbox gear ratio; selecting one or more of a plurality of preassembled, self-contained gear modules that have been determined to provide the desired gearbox gear ratio, each of the self-contained gear modules comprising a gear train encased by a module housing, the gear train including two or more intermeshed gear elements providing a predetermined gear ratio, the module housing having one or more coupling elements projecting radially outward therefrom; selecting one of a plurality of gearbox housings that has been determined to be configured to stow therein the selected self-contained gear module(s), the gearbox housing having an inner surface with one or more protrusions projecting radially inward therefrom, the one or more protrusions being configured to mate with the one or more coupling elements of the module housing(s) to thereby retain the gear module(s) in the gearbox housing; inserting the selected self-contained gear module(s) into the gearbox housing such that the gear module(s) successively mechanically couple with one another and such that the one or more coupling elements mate with the one or more protrusions; and, attaching at least one lid to at least one end of the gearbox housing.
The above summary is not intended to represent each embodiment or every aspect of the present disclosure. Rather, this summary merely provides an exemplification of some of the novel features presented herein. The above features and advantages, and other features and advantages of the present disclosure, will be readily apparent from the following detailed description of exemplary embodiments and modes for carrying out the present invention when taken in connection with the accompanying drawings and the appended claims.
While aspects of this disclosure are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
This invention is susceptible of embodiment in many different forms. There are shown in the drawings and will herein be described in detail representative embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiments illustrated. To that extent, elements and limitations that are disclosed, for example, in the Abstract, Summary, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference or otherwise. For purposes of the present detailed description, unless specifically disclaimed: the singular includes the plural and vice versa; the words “and” and “or” shall be both conjunctive and disjunctive; the word “all” means “any and all”; the word “any” means “any and all”; and the words “including” and “comprising” mean “including without limitation.” Moreover, words of approximation, such as “about,” “almost,” “substantially,” “approximately,” and the like, can be used herein in the sense of “at, near, or nearly at,” or “within 3-5% of,” or “within acceptable manufacturing tolerances,” or any logical combination thereof, for example.
Disclosed herein are various representative motor-driven modular gearbox assemblies, modular gearbox kits, as well as methods of making and methods of using a modular gearbox assembly (as used herein, “gearbox” can refer to both reduction gearboxes and multiplier gearboxes). For some embodiments, the gearbox assembly is a power transmitting gear reducer. The modular gearbox assembly includes interchangeable planetary-gear inserts (also referred to herein as “gear modules” or “stages”) that can be selectively and removably coupled together (e.g., stacked one on top of the other) to meet the performance specifications of any motor manufacturer. Each stage can be clipped or otherwise mechanically fastened together using one or more conventional mechanical fasteners. Optionally, the individual stages, once properly aligned with and inserted into the outer housing, can be bonded together (e.g., via adhesives) or welded together (e.g., via sonic welding). The interchangeable stages can be rearranged or replaced, for example, to provide alternative performance characteristics or as a means of fixing a defective gearbox assembly.
The outer housing of the modular gearbox assembly can be “universal” in that it is configured to receive, couple with, and stow any assortment of the interchangeable planetary-gear inserts, e.g., to provide an endless variety of speed and torque ratios. The housing size can also be changed to allow for greater or fewer stages—e.g., 1 stage, 2 stage, 3 stage, 4 stage, etc. The housing size can also be modified to allow for larger or smaller planetary-gear inserts. The outer housing can be fabricated from any known material to have sufficient rigidity and desired structural characteristics for the intended application of a gearbox assembly. In at least some aspects of the disclosed concepts, the housing may be formed from polyoxymethylene (POM) or other acetal plastic. For some desired implementations, the housing is fabricated, in whole or in part, from a mineral-filled nylon or other type of moldable plastic, for example, to help ensure that a range of temperatures and vibrations can be accommodated. In some embodiments, acetal plastic filled with Teflon or silicone or other known fillers is used for the gears modules and/or gear members.
The modular gearbox assembly can include a flexible beam coupler or other input mechanism which allows the gearbox to operatively couple to the output shaft of any motor assembly. The flexible beam coupler, which may be in the nature of a spiral beam coupler, can be configured to attach to a shaft with up to a 12 degree angular velocity. The modular gearbox assembly can include a flexible beam coupler or other output mechanism which allows the gearbox assembly to operatively couple to the input shaft or input mechanism of any driven mechanism.
For some configurations, the modular gearbox assembly includes one or more endplates (or “lids”) attached to and closing off one or more ends of the gearbox housing. In one example, a motor mounting plate can be coupled to an input end of the gearbox outer housing via one or more bolts. For some configurations, the motor mounting plate can be coupled to the outer housing via one or more clips, snap fasteners, or other mechanical fasteners. In this regard, an output lid can be attached to and close off an output end of the gearbox housing on the opposite side of the input end where the motor mounting plate is attached.
If a customer has a different output torque or speed requirement, or a different input torque or speed requirement, the disclosed assembly allows for selective modification of one or more of the individual stages (as opposed to the custom fabrication of the entire assembly). For instance, the width, the pitch, the material, etc., for one or more of the stages can be adapted to a customer's individual specifications.
In some embodiments, the entire assembly or substantially the entire assembly is fabricated from plastic or other known polymeric and synthetic materials, such as the aforementioned POM plastic. For some embodiments, one or more components can be overmolded or undermolded with plastic. Optionally, one or more components can be fabricated, in whole or in part, from metallic materials. For instance, the first and second stages of the gearbox assembly can be fabricated entirely or predominantly from metal. In a high-torque application and/or applications with an initial startup of a higher RPM or high startup input torque, the first stage or the first few stages can be fabricated entirely or predominantly from metal, and the subsequent stages can step be fabricated entirely or predominantly from plastic.
It may be desirable for some configurations to be compatible with National Electrical Manufacturers Association (NEMA) size motors 23 and down. Some configurations are compatible with motor sizes that are higher than NEMA size 23. In addition, the modular gearbox assembly can be scalable—i.e., it can take on various shapes and sizes. By way of example, the gearbox can be 1 square inch, 2 square inches, or larger. Optionally, the gearbox outer housing can be polyhedral (e.g., box shaped), toroidal (e.g., cylindrical), spherical, or other shape, as may be desired or required by a customer's intended application.
Various gearbox assemblies are disclosed herein, including 1-stage, 2-stage and 3-stage gearboxes. The gearbox assemblies can comprise any number or combination of parts, sub-assemblies, and/or assemblies described above and/or depicted in the accompanying figures. The gearbox assemblies can include a single gear type or any assortment of gears, including spur gears, helical gears, bevel gears, spiral gears, worm gears, etc. The present concepts also include various gearbox kits, which may comprise any number of, or combination of, parts, sub-assemblies, and/or assemblies described herein and/or depicted in the accompanying figures, in whole or in part.
The present concepts also include methods of assembling a gearbox assembly. For example, a method of assembling a gearbox assembly may include: providing a plurality of interchangeable planetary-gear inserts, each comprising a respective gear ratio and/or a respective torque ratio; providing a housing configured to receive therein and attach to any combination of the interchangeable planetary-gear inserts; determining which of the plurality of interchangeable planetary-gear inserts are required to provide a desired mechanical advantage (e.g., output speed and/or output torque); inserting the determined interchangeable planetary-gear inserts into the housing such that the inserts are concentrically aligned with and operatively connected to each other; and, attaching one or more end plates to the housing. In addition, the present concepts also encompass methods of manufacturing a gearbox assembly as well as methods of using a gearbox assembly.
Numerous representative embodiments, options, features and alternatives are presented in various forms in the following discussion and corresponding figures. Each of these options and features, and other now known and hereinafter developed options and features, can be incorporated into any of the disclosed embodiments unless explicitly disclaimed or otherwise logically prohibited. By way of non-limiting example, the elements, options, features and alternatives described below with respect to 3-stage modular gearbox assemblies, whether spur-gear-type assemblies or bevel-gear-type assemblies, can be incorporated into the disclosed 2-stage and 1-stage embodiments, and vice versa, without departing from the intended scope and spirit of the present disclosure.
Referring now to the drawings, wherein like reference numbers refer to like components throughout the several views, there is shown in
In the embodiment presented in
Attached at an input (“front”) end of the gearbox housing 12 is a motor mounting lid 16, while attached on the opposite side of the gearbox housing 12 at an output (“rear”) end thereof is an output lid 18. As shown, the motor mounting lid 16 is attached to the gearbox housing 12 via one or more threaded fasteners, which may be in the nature of four flat-head bolts 22, each of which passes through a corresponding slot (not visible in the views provided) in the motor mounting lid 16 and into a complementary threaded anchor 24 (three of the four of which can be seen in
As an input member, the modular gearbox assembly 10 includes an input coupler 30 (
As seen in
The output coupler 32 passes longitudinally through a third coupler hole 17, which extends through a centrally located section of the output lid 18, and couples (e.g., is keyed and press-fit into) the center of a third “intermediate” gear member 38C of the third gear module 14C. Optionally, the output coupler 32 can mechanically couple to another gear member of the third gear module 14C or, if the order of the stack of gear modules 14A-C was changed, to another gear module altogether. An axial bearing 42, which circumscribes and attaches to a proximal portion of the output coupler 32, rotatably mounts the output coupler 32 inside the third coupler hole 17 of the output lid 18. A flange portion 45 of the axial bearing 42 is circumscribed by and seated at least partially inside of a complementary portion of the third coupler hole 17; the complementary portion of the hole 17 and the flange 45 having generally equal diameters. The flange portion 45 is nested between the output lid 18 and the third gear module 14C such that the output coupler 32 is concentrically aligned for common rotation with the third “intermediate” gear member 38C. It is within the scope of this disclosure to employ radial, axial and other types of bearings at various locations within the assembly 10.
With continuing reference to
Continuing with the above example, the third planetary gear set of the third gear module 14C comprises a third “outer” gear member 36C (or “ring gear”) that circumscribes a third “inner” gear member 34C (or “sun gear”). A third “intermediate” gear member 38C comprises a plurality of planet gears 39C that are rotatably mounted on a third carrier member 37C (or “planet carrier”). In the illustrated embodiment, there are four planet gears 39C mounted on the planet carrier 37C. Each planet gear 39C is continuously meshingly engaged with both the ring gear member 36C and the sun gear member 34C. The third planetary gear set will typically have a third predetermined gear ratio (e.g., a 3.0-ratio third stage) and, thus, offer a specific torque ratio and speed ratio, which may be similar to or distinct from the torque and speed ratios of the first and second planetary gear sets. Similar to the first and second gear modules 14A, 14B, the ring gear 36C acts as the module housing for the third gear module 14C, with the various gear members of the third planetary gear set being circumscribed or otherwise encased by the module housing. Optionally, the module housing and ring gear may each be fabricated as separate parts that are thereafter attached together. As shown for illustrative purposes in
Once assembled, the input coupler 30 is rigidly attached (e.g., via sonic welding and/or keyed shaft) for common rotation with the first inner gear member 34A of the first gear module 14A. The first intermediate gear member 38A of the first gear module 14A is rigidly attached (e.g., via sonic welding and/or keyed shaft) for common rotation with the second inner gear member 34B of the second gear module 14B. Likewise, the second intermediate gear member 38B of the second gear module 14B is rigidly attached (e.g., via sonic welding and/or keyed shaft) for common rotation with the third inner gear member 34C of the third gear module 14C. The third intermediate gear member 38C is rigidly attached (e.g., keyed and press-fit) for common rotation with the output coupler 32, as described above. Optionally, each of the gear modules 14A-14C can mechanically couple to a different gear member of the adjacent gear module than what is shown in the drawings. In this regard, the order of the gear modules 14A-C can be changed such that the modules mechanically couple to a different one or ones of the gear modules than what is shown in the drawings.
When the modular gearbox assembly 10 is assembled and, thus, the gear modules 14A-C are properly aligned and interconnected inside of gearbox housing 12, torque and rotational velocity can be transferred from the external driving mechanism into the gearbox housing 12 to the planetary gear train via the input coupler 30. The gear ratio of the planetary gear train increases or decreases the torque and/or rotational velocity of the driving mechanism, which is then transmitted to the driven mechanism via the output coupler 32. The gear ratio of the planetary gear train is directly correlated to the individual gear ratios of the constituent planetary gear sets. In the illustrated example, the 7.0-ratio first stage, 4.0-ratio second stage and 3.0-ratio third stage combine to provide a three-stage 84.0-ratio gear reduction assembly.
According to the illustrated embodiment, the three planetary gear sets each comprises a “simple” planetary gear set. However, one or more of the planetary gear sets described above can be either “simple”—e.g., comprising a single-pinion carrier assembly—or “compound”—e.g., comprising a multi-pinion carrier assembly. Compared to simple planetary gear sets, compound planetary gear sets have the advantages of larger gear ratios, higher torque-to-weight ratios, and more flexible configurations. Embodiments with long pinions are also possible. In the same vein, the intermeshed gears themselves may take on alternative configurations (e.g., spur, helical, spiral, etc.) with different structural characteristics (e.g., pitches, tooth counts, radii, thicknesses, etc.).
In some embodiments, one or more of the constituent parts of the gear modules 14A-C are common to each other (i.e., substantially structurally identical). For example, the module housings 36A-C are, in some configurations, structurally identical. Optionally, the outer periphery of the housings, including the coupling elements described below (e.g., the flanges 54A-B of
The gearbox housing 12 of the modular gearbox assembly 10 is designed to stow and couple with various assortments and numerous arrangements of the interchangeable gear modules 14A-C such that the assembly 10 can provide any of a number of desired speed and torque ratios. The gearbox housing 12, for example, has one or more protrusions (and/or depressions, e.g., slots, channels, etc.) for operatively aligning, guiding, and retaining within the housing 12 the one or more gear modules 14A-C. The one or more protrusions are represented herein by a plurality of elongated rails (e.g., first, second, third and fourth rails 50A-D, respectively, of
Each of the gear module housings 36A-C has one or more coupling elements for mating with the aforementioned protrusions (and/or depressions) to thereby retain the gear modules 14A-C inside the gearbox housing 12. By way of example, and not limitation, the one or more coupling elements are represented in the drawings by a first plurality of flanges 54A which project radially outward from the outer periphery of the first module housing 36A and a second plurality of flanges 54B which project radially outward from the outer periphery of the second module housing 36B. Each flange 54A-B is shown as a substantially or completely flat plate with a reinforcement arm projecting orthogonally therefrom. Each of the flanges 54A-B is positioned and oriented to align with and press against at least one of the rails 50A-D and thereby operatively align the gear module 14A-B inside the gearbox housing 12. It is within the scope of this disclosure to increase or decrease the number of flanges on one or more or all of the module housings. Alternative flange shapes, dimensions, locations and orientations from what is shown in the drawings are also within the scope and spirit of this disclosure.
Once the gear modules 14A-C are inserted into the gearbox housing 12, the protrusions 50A-D, 52A-B mate with the coupling elements 54A-B to thereby retain the gear modules 14A-C inside the gearbox housing 12. In accord with the illustrated embodiment, each set of ribs 52A-B of the gearbox housing 12 is designed to fit in between two opposing reinforcement arms of adjacent flanges 54A-B of a module housing 36A-B. In addition, the flat plate of each flange 54A-B presses against a corresponding rail 50A-D of the gearbox housing 12. The rails 50A-D and ribs 52A-B cooperate with the flanges 54A-B in the manner heretofore described to: (1) ensure that the gear modules 14A-B are properly oriented prior to being inserted into the gearbox housing 12; (2) guide the gear modules 14A-C into and out of the gearbox housing 12; and (3) prevent the module housings/ring gears 36A-B of the gear modules 14A-B from rotating. This configuration also allows the gear modules 14A-C to be assembled inside of the gearbox housing 12 between the input and output couplers 30, 32 in any of a variety of different arrangements (e.g., the third gear module 14C could be positioned in the middle or at the front end of the stack, while the first gear module 14A could be positioned in the middle or at the rear end of the stack). In some embodiments, one or more of the flanges 54A-B on each of the module housings 36A-B includes a fastener slot 56A-B that is configured to receive therein a complementary fastener (e.g., a screw 20) to thereby lock the gear module 14A-B inside the gearbox housing 12.
Other aspects of this disclosure are directed to gearbox kits for assembling a gearbox assembly that is operable to receive, modify and transmit the power output of a driving mechanism. As indicated above, the illustrated components of the modular gearbox assembly 10 presented in
A representative gearbox kit contains, for example, a plurality of self-contained gear modules, such as the first, second and third gear modules 14A, 14B and 14C of
Each kit will also include at least one and, in some implementations, multiple gearbox housings, such as gearbox housing 12 of
Improved methods for assembling a gearbox assembly and improved methods for using a gearbox assembly are described below in accordance with aspects of the present disclosure. These methods will be described with reference to the various aspects and features shown in
In accordance with one embodiment, a method is presented for assembling a gearbox assembly (e.g., modular gearbox assembly 10 of
This method also includes selecting a gearbox housing (e.g., gearbox housing 12) from a plurality of available gearbox housings (e.g., any of the gearbox housings disclosed herein and/or illustrated in the drawings), the selected gearbox housing having been determined to be shaped and sized to stow therein the selected gear modules. The gearbox housing has an inner surface with one or more protrusions projecting radially inward therefrom, the protrusions being configured to mate with the coupling elements of the module housing(s) to thereby attach the gearbox housing to the selected gear module(s). The method further comprises inserting the selected self-contained gear module(s) into the gearbox housing such that the gear modules successively mechanically couple with one another and such that the coupling element(s) mate with the protrusion(s). The method may then include attaching at least one lid (e.g., the motor mounting lid 16 and/or output lid 18 of
The method may further comprise attaching an input coupler (e.g., flexible beam coupler 30) and/or an output coupler (keyed shaft 32) to the gearbox housing. The input coupler is configured to attach to the driving mechanism and transmit the power output therefrom to the gear module(s) stowed in the gearbox housing. In contrast, the output coupler is configured to output from the gearbox housing the modified power output. In some embodiments, the module housings of some or all of the self-contained gear modules are structurally identical. In some embodiments, the predetermined gear ratios of some or all of the self-contained gear modules are distinct. In some embodiments, the protrusions are rails that extend longitudinally along the length of the gearbox housing, and the coupling elements are flanges which abut the rails and operatively align the gear module inside the gearbox housing.
In some embodiments, the method includes at least those steps enumerated above. It is also within the scope and spirit of the present invention to omit steps, include additional steps, and/or modify the order presented above. It should be further noted that the above method can be representative of a single sequence for assembling a gearbox assembly. However, it is expected that the method will be practiced in a systematic and repetitive manner to assembly multiple gearbox assemblies.
Turning next to
In the embodiment presented in
In contrast to the embodiment set forth in
Like the gearbox housing 12 of
As shown, the 2-stage bevel-gear-type modular gearbox assembly 210 can be an amalgamation of components from the other disclosed embodiments. For example, the modular gearbox assembly 310 utilizes the output lid 18, the input coupler 30, the output coupler 32 and axial bearing 42 of
While many embodiments and modes for carrying out the present invention have been described in detail above, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/834,248, which was filed on Jun. 12, 2013, and is incorporated herein by reference in its entirety and for all purposes.
Number | Date | Country | |
---|---|---|---|
61834248 | Jun 2013 | US |