CROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application No. 63/362,031, filed March 28, 2022, entitled CUSTOMIZABLE MODULAR EQUIPMENT AND POWER SYSTEM AND METHODS OF USE which application is incorporated herein in its entirety by reference.

BACKGROUND

[0002] Carts, hand carts, and hand trucks are used to assist in transporting materials, goods, baggage and the like. The heavier the items to be transported the more challenging transportation becomes. Similarly, the more difficult or varied the terrain, the more challenging transportation becomes. Manual hand carts and hand trucks, such as those available from Magliner® (www.magliner.com), can carry heavy leads. Gator™ Utility Vehicles are an off-highway gas vehicle with a cargo bed (available from John Deere (https://www.deere.com/en/gator-utility-vehicles/)) are currently used to move heavy items, but are unsuitable for use on varied terrain, streets or sidewalks. The cargo bed of the Gator is less than a manual hand truck.

[0003] What is needed is a versatile cart or transport vehicle that is capable of use on the street, sidewalks, and uneven surfaces with enough power to move heavy equipment. Additionally, what is needed is customizable modular equipment transport vehicle and power system. SUMMARY

[0004] Disclosed is a cart capable of use on the street, sidewalks, and uneven surfaces capable of moving heavy equipment. Additionally disclosed are customizable modular carts or equipment transport vehicle and power systems. The customizable modular equipment transport vehicle and power systems can be mobile and motorized. Additionally, the customizable modular equipment transport vehicle and power systems can be controlled by software, and include one or more sensors for collecting information and/or facilitating use, control and/or operation of the systems.

[0005] The customizable modular equipment transport vehicle and power systems can be a motor assisted hand cart or motorized hand cart. The motor assisted hand cart is not categorized as a vehicle and thus does not require vehicle or heavy tool training. The motorized hand cart uses controls that take the physical force applied to a non-motorized cart and enhances the force in a scaled response through motor control to move the cart across a variety of terrains and surfaces.

[0006] The customizable modular equipment transport vehicle and power system is (e.g., customizable modular cart) is configurable to include a control handle interface is provided that applies directional force and translational force (e.g., twist, push, pull, etc.) in a pre-prescribed scale of translational force to direct the motor assisted cart to move in a manner that would occur without motor assistance in order to achieve a determined configuration. A battery management system is provided that oversees the management, combining, charging and discharging of the battery system. The battery system is comprised of individual battery blocks (e.g., battery sets in custom battery housing) for hot-swappable combining and deployment of single or battery groups as point-of-use and off-cart power source. The motor assisted cart system allows batteries to be connected through an on-boarding protocol and allows for removal through a process of dismounting both through a battery management system and physical dismounting when a safe indicator is displayed. Battery management allows batteries with similar characteristics and/or level of charge to be combined on the same charging circuit at the same voltage and amperage.

[0007] Software can be provided that facilitates operation of the customizable modular equipment transport vehicle and power systems. The software can be installed on the customizable modular equipment and power systems or accessible via a network. Software can provide a variety of functions including control of computer assisted driving.

[0008] Additionally, the customizable modular equipment transport vehicle and power systems can include sensors operable to collect environmental information about the customizable modular equipment transport vehicle and power systems location including, but not limited to temperature, humidity, altitude, device height (e.g., location of a center of gravity for the device above a surface), light detection and ranging devices (LIDARs), ultrasonic devices, radar devices, inertia measurement unit (IMUs), and/or global positioning devices (GPS).

[0009] Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed. INCORPORATION BY REFERENCE

[0010] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

[0011] US 7,506,879 Bl published 3/24/2009 to Frahm et al.;

[0012] US 8,069,939 Bl published 12/6/2011 to Metzler;

[0013] US 8,967,634 B2 published 3/3/2015 to Barnes et al.;

[0014] US 9,365,225 B2 published 6/14/2016 to Henao;

[0015] US 10,272,937 B2 published 4/30/2019 to Chen et al.;

[0016] US 11,182,623 B2 published 11/23/2021 to Oh et al.;

[0017] US 11,199,846 B2 published 12/14/2021 to Luo et al.;

[0018] US 11,199,839 B2 published 12/14/2021 to Jiang et al.;

[0019] US 2020/0048058 Al published 2/13/2020 to Schwalbach et al.

[0020] Backstage Magliner Senior Cart accessed from https://www.magliner.com (11/2021);

[0021] Chapman PeeWee Dolly accessed from https://www.chapman- leonard.com/details.php7products id=12 (2/2022);

[0022] Club Car Golf Cart accessed from https://www.clubcar.com/en-us (2/2022);

[0023] Deeter Cart / Beach Buster: accessed from https://vimeo.eom/216069921 (2/2022);

[0024] Fisher Dolly accessed from http://www.jlfisher.com/dollies/model 10 dolly/index.asp (2/2022); [0025] Gator™ Utility Vehicles available from John Deere accessed from https://www.deere.com/en/gator-utility-vehicles/ (11/2021); and

[0026] Pug Electric Cart accessed from https://www.pugtechnologies.ca (2/2022).

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

[0028] FIGS. 1A-C arc upper perspective views of a customizable modular equipment transport vehicle and power system;

[0029] FIG. 2 is a top view of a customizable modular equipment transport vehicle and power system;

[0030] FIG. 3 is a side view of a customizable modular equipment transport vehicle and power system;

[0031] FIG. 4 is a front view of a customizable modular equipment transport vehicle and power system;

[0032] FIG. 5 is a back view of a customizable modular equipment transport vehicle and power system;

[0033] FIG. 6 is a top perspective view of a customizable modular equipment transport vehicle and power system;

[0034] FIG. 7 is a top perspective view of a customizable modular equipment transport vehicle and power system with an interior view of the system; [0035] FIG. 8 is a bottom perspective view of a customizable modular equipment transport vehicle and power system;

[0036] FIG. 9 is a bottom planar view of a customizable modular equipment transport vehicle and power system;

[0037] FIG. 10 is an upper perspective view of a customizable modular equipment transport vehicle and power system;

[0038] FIG. 11 is another upper perspective view of a customizable modular equipment transport vehicle and power system;

[0039] FIG. 12 is a perspective view of a customizable modular equipment transport vehicle and power system carrying a load;

[0040] FIGS. 13A-E are perspective and top views of a customizable modular equipment transport vehicle and power system illustrating various loading features;

[0041] FIG. 14 illustrates a perspective view of a customizable modular equipment transport vehicle and power system

[0042] FIG. 15 illustrates a perspective view of a customizable modular equipment transport vehicle and power system;

[0043] FIGS. 16A-B illustrates a side and perspective view of a customizable modular equipment transport vehicle and power system in use;

[0044] FIGS. 17 illustrates a perspective view of a customizable modular equipment transport vehicle and power system in use; and

[0045] FIG. 18 illustrates a perspective views of a customizable modular equipment transport vehicle and power system in use. DETAILED DESCRIPTION

[0046] FIGS. 1A-C are perspective views of a customizable modular cart or modular equipment transport vehicle and power system or cart 100 from an top surface view. The cart 100 has a body 110 with an upper surface 112, a front side 114, a rear side 116, and two sides 118. One or more rail sockets 113. The body 110 can further comprise a frame and a plurality of frame elements.

[0047] A steering mechanism 130 is provided which, in this configuration, has a vertical member 134 that passes through a steering aperture 131 in the upper surface 112 of the cart 100, and a horizontal bar 132 positioned at an upper end of the vertical member (the lower end of the vertical member engaging the wheel). The steering aperture 131 is larger than the diameter of the vertical member 134 which allows the vertical member 134 to move in, for example, a forward and backward direction during use which results in the vertical member 134 positioned at an angle other than 90 degrees from the upper surface 112 of the cart 100. The horizontal bar 132 can have a surface treatment along a portion thereof that facilitates secure interaction with a user. The surface treatment can be a change in texture of the exterior surface of the horizontal bar 132 or application of an exterior tubular member such as a rubber sheath which may have surface texturing. The configuration in FIGS. 1A-C is depicted with three wheels 150, two wheels at the end of the cart 100 opposite the steering mechanism 130 or handle (the back end of the cart), and one wheel at the front end of the cart 100. The single wheel positioned at the front of the cart 100 is positioned centrally between the two sides of the body 110. One or more impact resistant bumpers 140 are provided on the comers of the cart 100, e.g., at a first front edge where the front side 114 meets a first side and a second front edge where the front side 114 meets a second side, and at a first back edge where the rear side 116 meets a first side and a second back edge where the back side 116 meets a second side. A guard rail 120 can be provided on either side of the body 110. The guard rail 120 can removably connected to the two sides 118 of the body 110 and operable to rotate upward (r). Each of the two sides 118 can include one or more strap attachment apertures 119. The strap attachment apertures 119 can include a rubber grommet 119’ that protects any strap that might be passed through the strap attachment aperture 119 from friction damage that might occur when during use as a strap engages the cargo positioned on an upper surface of the cart 100. Additionally, the guard rail can have apertures.

[0048] A single bar handle would be, for example, a grab handle that converts push, pull, twist and torque influence with an ability to determine hand position, placement and degree of force and/or effort to translate the effort into a scale reaction by the cart. The handle bar can be a planar bar, an open circular ring, an triangular shape, or any other shape suitable to allow for operation of the modular equipment transport vehicle [0049] FIG. IB shows the cart 100 with two guard rails 120 rotated in an upward direction. The guard rails 120 are elongated planar elements that have one or more elongated hold-down apertures or slots 122, and one or more locking apertures 162. He guard rails are rotatable. The body 110 of the cart 100 has one or more posts 160 that extend perpendicularly from the side 118 of the body 110. The posts 160 The post 160 have a first diameter near the body 110 and a second diameter, larger than the first diameter, away from the body 110. The posts 160 are operable to engage the locking aperture 162 on the guard rails 120. The locking aperture 162 has a length with a first width at a first end and a second width at a second end that is less than the first width. In use, the guard rail is rotated upward and a post 160 passes through the first width of the locking aperture 162. The guard rail 120 can be moved in a first direction toward the front side 114 of the body 110 and a second direction toward the rear side 116 of the body 110. Movement of the guard rail 120 when the post 160 has been passed through the larger diameter portion of the locking aperture 162 causes the post 160 to be positioned through the smaller diameter portion of the locking aperture 162 which prevents the guard rail 120 from rotating downward towards the undeployed position showed in FIG. 1A.

[0050] FIG. 1C illustrates the cart 100 with a plurality of representative cargo elements 20 positioned on the upper surface 112 of the cart 100. The cargo elements 20 arc represented as rectangular boxes. However, as will be appreciated by those skilled in the art, the cargo elements 20 can have any shape or configuration.

[0051] FIG. 2 is a top view of a customizable modular equipment transport vehicle and power system or cart 100. From the top view, the upper surface 112 of the cart 100 is viewable, along with the one or more rail sockets 113. The rail sockets 113 allow for mounting of posts (e.g., speed rails) which allows for the use of additional rigging points and the ability to provide for secondary platforms and support. The overall dimensions of the cart 100 has a length L and a width W which can be, for example, 26 to 32 inches in a first dimension (e.g. 28 inches wide) and 55 to 65 inches in length in a second dimension (e.g., 60 inches long). The sizing allows the cart 100 to fit on remain stable on a variety of surfaces and to within a standard lift gate and within an aisle of, for example, a film truck. [0052] FIG. 3 is a side view along the longer edge of a customizable modular equipment transport vehicle and power system or cart 100. From the side view the handle 130 is positioned at a first end of the cart 100. One or more slots 122 are provided along the length of the guard rail 120. The slots 122 can be used for tie-downs and lifting points. As described above, the one or more locking apertures 162 can be provided to engage and lock into one or more corresponding posts 160 on the side of the cart 100 when the guard rail 120 is rotated into an upward vertical position from a downward vertical storage position and moved in a forward or backward direction (e.g., towards the front of the cart or away from the front of the cart). The post 160 and the corresponding locking aperture 162 is a locking mechanism. The body 110 of the cart 100 can have one or more attachment apertures 119 along the length which include rubber edged grommets 119’.

The attachment apertures 119 can be used in combinations with straps to secure cargo onto the upper surface of the body 110.

[0053] FIG. 4 is a front view of a customizable modular equipment transport vehicle and power system or cart 100. From this view, the two wheels 150 at a first end are positioned toward the sides of the body 110, while the single wheel at the second end that engages the handle 130 appears to be positioned between the two wheels. The wheels 150 can be high torque hub motors with all terrain tires. Status indicating headlights 410, 412, 414, 416 are provided, along with a light positioned underneath the frame to provide an underglow for improved night visibility of the terrain.

[0054] FIG. 5 is a back view of a customizable modular equipment transport vehicle and power system or cart 100. This end of the cart 100 can have, for example a charging socket 510. A 60 amps bates connector can be provided as well as a NEMA 5-15 receptacle.

[0055] FIG. 6 is a top perspective view of a customizable modular equipment transport vehicle and power system or cart 100. The upper surface 112 can be or include a reinforced cargo deck. The cargo deck can be removeable. FIG. 7 illustrates an interior view of the cart 100. Chain steering linkage 710 is provided for adjustable sensitivity when steering the cart 100. An internal battery 720, such as a rechargeable battery, can be provided to provide power to the cart 100 during use. Additionally a fast charger 722 can be provided. The fast charger 722 can be 110 V or 220 V. One or more upper crossmembers 730, 732 can be provided. The upper cross-mcmbcrs 730, 732 can provide structural support to the cart 100 and/or provide a surface upon which a reinforced cargo deck is placed. A magnetic deck retention member 740 can be provided along a length of either side of the cart 100 to further provide support for and secure the cargo deck. The magnetic deck retention member 740 has a length along at least a portion of the sides of the cart and a width less than the length. When installed, the magnetic deck retention member 740 provides a planar surface that engages an exterior surface of the lower surface of the cargo plate. Other deck retention mechanisms can be used without departing from the scope of the disclosure. For example, the deck retention member can be configured to allow the deck to be retained via screws, bolts, clips or other mechanical securement mechanism. For example, the deck retention member can include a plurality of apertures or threaded apertures sized to receive a screw or bolt.

[0056] FIG. 8 is a bottom perspective view of a customizable modular equipment transport vehicle and power system or cart 100. From the bottom view, all three wheels 150 are visible. The frame 110 further comprises a plurality of lower frame elements within the body 110. A first pair of lower frame elements 812, 814 is positioned between the front wheel and the rear wheels 150 of the cart 100 with a first end of the lower frame elements engaging a first side of the cart and a second end of the lower frame elements engaging the second side of the cart. A second pair of lower frame elements 816, 818 is provided that are positioned parallel to the two sides of the cart 100 and engage the first lower frame element 812 on a first end and engage the second lower frame element 814 on a second end. As illustrated, the second pair of lower frame elements 816, 818 are positioned perpendicularly to the respective pair of first frame elements.

[0057] FIG. 9 is a top planar view of a customizable modular equipment transport vehicle and power system or cart 100. As appreciated from this view, the magnetic deck retention mechanism 740 is positioned below the top deck when the cargo plate is removed and extends interiorly from the body 110 of the cart 100.

[0058] FIG. 10 is an upper perspective view of a mobile customizable modular equipment transport vehicle and power system or cart 1000. The cart 1000 has a corrosion resistant frame with a plurality of frame elements and a plurality of wheels 1050. A plurality or removable and reconfigurable body panels are provided, such as side body panels 1012, and a removable central panel 1014. The body panels can be solid or cheeseplate with a plurality of apertures (e.g. machined aluminum with apertures) in the panel as illustrated. The removable central panel 1014 can be provided. When the central panel 1014 is removed, the height of any cargo to be transported is not limited to the height of the cart 1000. [0059] The front of the cart 1000 has a handle 1030 operable to pull or steer the cart 1000. The rear of the cart 1000 has one or more modular battery connections 1016, a power monitoring system which can have Bluetooth and/or Wifi capabilities. The Bluetooth and Wifi capability provide short range wireless communication functionality that allows for power monitoring of the cart 1000. Auxiliary power systems, such as auxiliary batteries, can be provided. The cart 1000 has a motor control unit 1020, an electric drive system 1032, and an AC inverter 1026. Power monitoring can be performed via, for example, Bluetooth and WiFi 1024. As is known in the art, the steering system converts movement of a steering mechanism, such as rotation of a steering wheel, into a swiveling movement of one or more wheels. The steering system can include, for example, a wheel connected to a steering column and a universal joint. The steering column with the universal joint engages a rack housing positioned between two wheels. A 15 inch diameter steering wheel, for example, moving four turns from full left lock to full right light travels nearly 16 feet while the edge of the road wheels moves a distance of only slightly more than 12 inches. The steering effort of a user passes to the wheels through a system of pivoted joints. The joints are designed to allow the wheels to move up and down with suspension without changing the steering angle. The steering system can be, for example, a rack and pinion system or a steering box system.

[0060] A central storage space 1022 exists between the front wheels and the rear wheels below the central removable section 1014, when installed.. The central storage space 1022 is sizable and configurable to allow for transportation of equipment such as a camera dolly. [0061] The plurality of wheels 1050 can have a tread pattern to improve traction during operation over a wide variety of surfaces. The components of the wheels inclde

[0062] The handle 1030 can be have a circular wheel interface for the user or a single-bar handle as shown in, for example FIG. 1A. Control can also be achieved via a joystick. [0063] The cart 1000 is configurable to carry, for example, a dolly and allows for easy transport and photography from a working position on the cart 1000. The cart 1000 is sized and configured to ride on trucks, lift gates and elevators in an unloaded or loaded configuration. Batteries can be combined for modular use on or off the cart. The cart 1000 is customizable and modularly configurable to provide for equipment transport. Additionally, the cart 1000 is motor assisted.

[0064] FIG. 11 is another upper perspective view of a cart 1000. From this view, the camera dolly transportation section 1112 is viewable without the removable central panel shown in FIG. 10. A power supply system 1160 can be provided, such as a built-in battery system. The power supply system can be rechargeable and include a connector panel 1162. The connector panel 1162 can be an electrical breakout panel with, for example, standard AC outlets, high-current lighting outlets, USB outlets and/or a battery monitor. The power system 1160 is built-in and positionable over a lateral frame element between the front wheels and an AC inverter 1126 is positioned over a lateral frame element between the rear wheels 1150. An electrical breakout panel 1162 with one or more of standard AC outlets, high current light outlets, USB outlets and battery monitor is in communication with the built in power system 1160. Modular battery connections 1116 are in direct or indirect communication with the AC inverter 1126. A motor control unit 1120 is also in provided that is in communication with the AC inverter 1126 and the modular battery connections 1116. An electric drive system 1132 is provided that is positionable below the AC inverter 1126 between the rear wheels 1150.

[0065] The cart 1000 can be provided with a steering and throttle control system for the cart 1100 at the front of the cart. The steering and throttle control is controllable via a steering wheel 1130. The cart system can be sized to fit a standard truck lift gate. Additionally reconfigurable cheese plate surfaces can be provided.

[0066] FIG. 12 is a perspective view of a cart 1000 and power system carrying a load of cargo such as that shown in FIG. 10. A central storage space 1022 or well can be defined between the front wheels and the rear wheels which allows for storage below a removably installed panel or cargo deck. The central storage space 1022 is sized and configured to carry an industry-standard camera dolly 1202. The sturdy aluminum frame 1210 can carry up to 2500 lbs. Independent all-wheel drive is provided to facilitate turning and off-road handling.

[0067] FIGS. 13A-E are perspective and top views of a customizable modular equipment transport vehicle and power system 1300 illustrating various loading features. As appreciated from these views, the system has a plurality of configurations depending on whether and where side panels, cargo deck (or cargo panel) are provided and whether and when guard rails or side guard panels are in a vertical position or a horizontal position. Side guard panels can be changed from a vertical upright position to a horizontal position. Cargo can be positioned in the central storage space 1022 with an upper surface placed on top and additional cargo placed on the upper surface. FIG. 13A illustrates a top perspective view of the cart 1000 with a plurality of cargo elements 1302 positioned on the upper surface of the cart 1000. FIG. 13B illustrates a top perspective view of the cart 1000 with side panels 1310 in a planer position to accommodate an a separately mobile piece of equipment 1304 such as a camera dolly. FIG. 13C illustrates side panels 1310 in a downward configuration (similar to FIG. 13B) without any cargo positioned on the lower deck surface 1312. In FIG. 13D the side panel 1310 is in an upward configuration to secure cargo elements 1302 between the front wheels and the rear wheels and underneath an upper panel 1014. FIG. 13E illustrates a top perspective view of the cart 1000 with the a first side panel 1310 and a second side panel in a planar position.

[0068] Battery packs can be provided to provide power to the system. The battery packs can have batteries positioned within a battery container with a removable lid that provides access to terminals and cell connectors while providing an environment that protects the batteries.

[0069] FIG. 14 illustrates a perspective views of a cart 1000 and power system with an upper rectangular frame 1410 with sides suitable for carrying equipment. The configuration in FIG. 14 provides two planar surfaces 1420, 1422 for placing cargo elements. Additional cargo elements are shown positioned in the central storage space between the front and rear wheels.

[0070] FIG. 15 illustrates a perspective view of a cart 1000 and power system with side panels 1310 between the front and rear wheels in a horizontal position carrying a wide cargo such as equipment 1304. An additional rear platform 1510 or cargo deck can be provided for carrying additional cargo 1512 such as a battery. Positioning the side panels 1310 is a lowered horizontal position allows equipment 1304 to be loaded on a central platform between the front and rear wheels 1050 which is wider than the overall width of the cart 1000. In some configurations a first side panel is positioned vertically while a second side panel is positioned horizontally. Vertical positioning of a side panel can allow the cargo to rest against the vertical side panel during transport.

[0071] FIGS. 16A-B illustrate a side and perspective views of a cart 1000 and power system. Suitable dimension are, for example, 71.50 inches from the front edge of the front wheels to the rear edge of the rear wheels, 53.5 inches from the center of the front wheels to the center of the back wheels, 6 inches from the ground to the bottom of the central portion of the frame between the wheels, 9.5 inches from the ground to the upper surface of the recessed central frame, 30.00 inches from the ground to an upper surface of the front or rear platform, 65.50 inches from a front end of the front platform to a rear end of the rear platform, 26.50 inches for a width of the central recess, with each side raised platform having a length of 18.50 inches. Additionally the cart can have a width of 44.0 inches from an exterior surface of a right wheel to an exterior surface of a left wheel, and a width of 42.0 inches of the platform.

[0072] FIG. 17 illustrates perspective views of a cart 1700 and power system. In this configuration, the cart 1700 has an upper rail system 1710 around the upper exterior surface. The upper rail system 1710 provide guard rails to contain cargo on the upper surface of the cart during transport. The side walls of the cart 1700 can be perpendicular to the ground or slightly angled as illustrated.

[0073] FIG. 18 illustrates a perspective views of a cart 1800 with a person sitting 10 on a platform surface of the cart 1800.

[0074] The customizable modular equipment transport vehicle and power system can be provided with a plurality of solid or cheese plate body panels, batteries, and rail systems. [0075] Note that some or all of the components as shown and described may be controlled by or implemented in software, hardware, or a combination thereof. For example, such components can be implemented as software installed and stored in a persistent storage device, which can be loaded and executed in a memory by a processor (not shown) to carry out the processes or operations described throughout this application. Alternatively, such components can be implemented as executable code programmed or embedded into dedicated hardware such as an integrated circuit (e.g., an application specific IC or ASIC), a digital signal processor (DSP), or a field programmable gate array (FPGA), which can be accessed via a corresponding driver and/or operating system from an application. Furthermore, such components can be implemented as specific hardware logic in a processor or processor core as part of an instruction set accessible by a software component via one or more specific instructions. The processes or methods depicted in the preceding figures may be performed by processing logic that comprises hardware (e.g. circuitry, dedicated logic, etc.), software (e.g., embodied on a non-transitory computer readable medium), or a combination of both. Additionally, although the processes or methods may be described in terms of some sequential operations, it should be appreciated that some of the operations described may be performed in a different order. Moreover, some operations may be performed in parallel rather than sequentially.

[0076] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.