Patent Publication Number: US-2023160962-A1

Title: Simulation of battery cell conditions

Description:
INTRODUCTION 
     The subject disclosure relates to batteries, and more particularly to simulation of defects and/or short circuits in battery cells. 
     Battery cells are used in various applications, such as automotive applications (e.g., in electric and hybrid vehicles). Batteries may be subject to various failure modes (e.g., soft short circuits) due to factors such as damage to battery components, excessive heat, dendrite growth and others. Testing for such failure modes can be challenging, and, as such, it is desirable to provide an ability to test for failure modes. 
     SUMMARY 
     In one exemplary embodiment, a device for simulating a battery condition includes a plurality of electrically conductive plates, the plurality of electrically conductive plates including a set of opposing plates having a first plate and a second plate. The device also includes an electrically conductive material extending between the first plate and the second plate, the electrically conductive material in electrical contact with the first plate and the second plate and defining at least part of an electrical path from the first plate to the second plate, the electrically conductive material having a resistance selected to simulate the battery condition in response to activating the device. 
     In addition to one or more of the features described herein, the device further includes a conductor having a first end in contact with the first plate, the device configured to be activated by putting a second end of the conductor in electrical contact with the second plate, where a distance between the first plate and the second plate is selected to simulate the battery condition when the conductor is in electrical contact with the first plate and the second plate. 
     In addition to one or more of the features described herein, the battery condition is a soft short circuit occurring at an interior of a battery. 
     In addition to one or more of the features described herein, the electrically conductive material is a porous material, the resistance of the electrically conductive material is higher than a resistance of the first plate and a resistance of the second plate, and the electrically conductive material defines a diffuse current path between the first plate and the second plate. 
     In addition to one or more of the features described herein, the electrically conductive material includes one or more current paths between the first plate and the second plate, the one or more current paths having a resistance that is less than the resistance of the electrically conductive material. 
     In addition to one or more of the features described herein, the first plate, the second plate and the electrically conductive material define a space therein, the space extending from the first plate to the second plate, and the conductor is disposed in the space. 
     In addition to one or more of the features described herein, the electrically conductive material is a compliant material, and the device is configured to be activated by compressing the electrically conductive material to put the second end in electrical contact with the second plate. 
     In addition to one or more of the features described herein, the device is configured to be activated by moving the second end into electrical contact with the second plate. 
     In addition to one or more of the features described herein, the plurality of conductive plates include a plurality of sets of conductive plates, and the conductive material is disposed between opposing plates in each set of conductive plates. 
     In one exemplary embodiment, a method of simulating a battery condition includes connecting a battery simulation device to a power source, the battery simulation device including a plurality of electrically conductive plates, the plurality of electrically conductive plates including set of opposing plates having a first plate and a second plate. The device also includes an electrically conductive material extending between the first plate and the second plate, the electrically conductive material in electrical contact with the first plate and the second plate and defining at least part of an electrical path from the first plate to the second plate. The method also includes activating the device to simulate the battery condition by performing at least one of: changing a distance between the first plate and the second plate, and moving a conductor disposed between the first plate and the second plate, measuring an electrical signal from the device, and determining a signature associated with the battery condition based on the electrical signal. 
     In addition to one or more of the features described herein, the distance between the first plate and the second plate and a resistance of the electrically conductive material are selected to simulate the battery condition when the conductor is in electrical contact with the first plate and the second plate. 
     In addition to one or more of the features described herein, the conductor has a first end in contact with the first plate, and activating the device includes putting a second end of the conductor in electrical contact with the second plate. 
     In addition to one or more of the features described herein, the electrically conductive material is a porous material having a resistance that is higher than a resistance of the first plate and a resistance of the second plate, the electrically conductive material defining a diffuse current path between the first plate and the second plate. 
     In addition to one or more of the features described herein, the electrically conductive material is a porous material having a resistance that is higher than a resistance of the first plate and a resistance of the second plate, the electrically conductive material including one or more current paths between the first plate and the second plate, the one or more current paths having a resistance that is less than the resistance of the electrically conductive material. 
     In addition to one or more of the features described herein, the first plate, the second plate and the electrically conductive material define a space therein, the space extending from the first plate to the second plate, and the conductor is disposed in the space. 
     In addition to one or more of the features described herein, the electrically conductive material is a compliant material, and activating the device includes compressing the conductive material to put the second end in electrical contact with the second plate. 
     In addition to one or more of the features described herein, the device is configured to be activated by moving the second end into electrical contact with the second plate. 
     In one exemplary embodiment, a computer program product includes a computer readable storage medium, the computer readable storage medium having instructions executable by a computer processor to cause the computer processor to perform a method. The method includes connecting a battery simulation device to a power source, the device including a plurality of electrically conductive plates, the plurality of electrically conductive plates including set of opposing plates having a first plate and a second plate. The device also includes an electrically conductive material extending between the first plate and the second plate, the material in electrical contact with the first plate and the second plate and defining at least part of an electrical path from the first plate to the second plate. The method also includes activating the device to simulate the battery condition by performing at least one of: changing a distance between the first plate and the second plate, and moving a conductor disposed between the first plate and the second plate. The method further includes measuring an electrical signal from a battery simulation device, and determining a signature associated with the battery condition based on the electrical signal. 
     In addition to one or more of the features described herein, the electrically conductive material is a compliant material, and activating the device includes compressing the electrically conductive material to put the conductor in electrical contact with the first plate and the second plate. 
     In addition to one or more of the features described herein, the first plate, the second plate and the electrically conductive material define a space therein, the space extending from the first plate to the second plate, the conductor is disposed in the space and has a first end in contact with the first plate, and activating the device includes putting a second end of the conductor in electrical contact with the second plate. 
     The above features and advantages, and other features and advantages of the disclosure are readily apparent from the following detailed description when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DES CRIPTION OF THE DRAWINGS 
       Other features, advantages and details appear, by way of example only, in the following detailed description, the detailed description referring to the drawings in which: 
         FIG.  1    depicts an example of a battery cell; 
         FIG.  2    is a representation of an example of a soft short circuit battery condition; 
         FIG.  3    depicts an embodiment of a battery simulation device in an inactive state, the battery simulation device including a compliant electrically conductive material and a conductor; 
         FIG.  4    depicts the battery simulation device of  FIG.  3    in an active state; 
         FIG.  5    depicts an embodiment of a battery simulation device in an inactive state, the battery simulation device including a compliant electrically conductive material and a conductor; 
         FIG.  6    depicts an embodiment of a battery simulation device in an inactive state, the battery simulation device including an electrically conductive material and a conductor, and a magnetic activation component; 
         FIG.  7    depicts an embodiment of a battery simulation device in an inactive state, the battery simulation device including a compliant electrically conductive material and a conductor, the electrically conductive material including one or more current paths; 
         FIG.  8    depicts an embodiment of a battery simulation device in an inactive state, the battery simulation device including sections of a compliant electrically conductive material and a conductor disposed between the sections; 
         FIG.  9    depicts an embodiment of a battery simulation device including a plurality of sets of conductive plates, each set of conductive plates having a compliant electrically conductive material therebetween; 
         FIG.  10    depicts an embodiment of a battery simulation device including a plurality of sets of conductive plates, each set of conductive plates having a compliant electrically conductive material therebetween; 
         FIG.  11    is a block diagram representing a method of manufacturing a battery simulation device and/or simulating a battery condition; and 
         FIG.  12    depicts a computer system in accordance with an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     In accordance with one or more exemplary embodiments, methods, devices and systems are provided for simulating a battery cell and simulating a failure mode or other condition of the battery cell. An embodiment of a simulation device is configured to simulate a failure mode or other condition of a battery cell and produce an electromagnetic signature associated with the simulated condition. The electromagnetic signature may be used to monitor the operation of a battery cell, non-destructively test the battery cell to detect failure modes (e.g., soft short circuits or “soft shorts”), and test non-contact sensors targeted for detecting soft shorts or other failure modes. Embodiments include methods of manufacturing simulation devices and simulating failure modes and/or other conditions using simulation devices. 
     Embodiments described herein present numerous advantages and technical effects. The embodiments provide means for simulating battery conditions in a reliable and repeatable manner, and for effectively determining electrical signatures associated with a soft short or other battery condition. The electrical signatures can be determined with a reduced or eliminated risk of hazards that can occur during conventional testing (e.g., testing of reject cells). 
       FIG.  1    depicts an example of a pouch-type battery cell  10  that can be simulated via the systems and methods described herein. It is noted that the systems and methods are not limited to simulation of the specific example of  FIG.  1   , or any other specific battery type. For example, embodiments described herein are also applicable to battery cells having rigid housings. 
     The battery cell  10  includes a flexible envelope or pouch  12  that is sealed to enclose a plurality of stacked unit cells (cell stack). The pouch  12  may be an aluminum laminated foil or other suitable pouch material. Each unit cell includes a negative electrode or anode  14 , and a positive electrode or cathode  16 . The anodes and cathodes are made from selected electrically conductive materials and may be configured as thin sheets or foils. Each unit cell also includes a separator  18  made from an electrically insulating material such as a polymer or a ceramic. An active material  20  such as a Lithium material is disposed in the pouch  12  between the various layers of the unit cells. 
     As shown in  FIG.  1   , each anode  14  (also referred to as an anode foil) extends away from the unit cells, and the anode foils  14  are attached together as a foil stack  22 . The foil stack  22  may be welded together and attached to an electrically conductive tab  24  via a weld  26  or other metal-to-metal joining procedure. The tab  24  in this example is a negative terminal tab. The cathode foils  16  may be similarly welded to a positive terminal tab (not shown) that extends to an exterior of the pouch  12 . 
     Various battery conditions or failure modes can occur during battery operation. One such failure mode is referred to as a soft short circuit, or simply a “soft short”, which can cause thermal runaway events.  FIG.  2    illustrates a portion of an interior of the battery cell  10 , and aspects of a condition of the battery cell  10  that can cause a soft short. 
     In this example, the battery cell  10  is a Lithium ion battery cell, which includes graphite anodes  14 , porous separators  18  and Lithium-based cathodes  16 . As shown, over the course of battery operation, Lithium dendrites  30  can grow, for example, due to impurities. The dendrites  30  are thin protrusions that can extend through the separator  18 . Over time, the dendrites  30  can cause the battery cell  10  to short circuit, which can render the battery cell  10  inoperable and/or result in thermal runaway. Simulation devices and methods described herein may be used to simulate this battery condition, other types of internal shorts (e.g., due to cell damage or tearing) or any other condition (e.g., a hard short, debris on one or more electrodes, etc.). 
       FIG.  3    depicts an embodiment of a simulation device  40  for simulating a battery cell, and simulating failure modes in a battery cell such as soft shorts. The device  40  includes a set of opposing electrically conductive plates, which includes a first plate  42  and a second plate  44 . The plates  42  and  44  may be made from any suitable conductive material, such as copper, steel, aluminum and/or other highly conductive material. A material  46  is disposed between the plates  42  and  44 , and defines one or more electrical paths for current to flow from one plate to another. As discussed further herein, the electrical paths may include diffuse or bulk current paths through the material  46  and/or defined current paths formed by increasing conductivity in regions of the material  46  (e.g., by depositing layers of more conductive material or impregnating regions of the material volume). 
     The material  46  may be any suitable conductive material that has a resistance that is greater that the resistances of the plates  42  and  44 . In an embodiment, the material  46  is a porous material, such as a foam, that is made from a material that is electrically conducting but has a higher resistance than the plates  42  and  44 . The porous material defines a diffuse electrical path between the plates. Any electrically conductive material can be used that has the higher resistance, such as carbon-impregnated polymer, carbon-impregnated rubber, ceramic and others. 
     The plates  42  and  44  and the material  46  define a space  48  that extends through the device  40 . A conductor  50  is fixedly disposed at or near the plate  42  and in electrical contact with the plate  42 . The conductor  50  may be made of copper, steel, aluminum, spring steel, or other conductive material. The conductor  50  includes a first end  51  attached to the plate  42  or otherwise disposed in electrical contact with the plate  42 , and a second end  52  that extends into the space  48 . When in an inactive state (shown in  FIG.  3   ), the second end  52  is held in a position that is away from the plates and the material  46 , such that no current can flow through the conductor  50 . 
     To place the device  40  in an active state, the second end  52  may be brought into electrical contact with the plate  44  (e.g., by compressing the material  46  or moving the second end  52 ). “Electrical contact” between two components refers to a condition wherein an electrical current can be passed between the components. Electrical contact may or may not entail physical contact between components. 
     Various properties of the device  40  can be selected so as to simulate a failure mode or other condition. The properties may include the type of material  46 , the resistivity of the material  46 , a distance D between the plates  42  and  44 , the material of the plates  42  and  44 , conductor material and/or configuration of electrical paths. 
     For example, the plates  42  and  44  are made from aluminum or other metal, and the conductor  50  is made from a metal such as copper. The material  46  in this example includes a conductive foam, such as carbon-filled polymer or rubber foam. The foam has a resistivity of about 10 Ohms, and the distance D is about 3 mm. Other resistivity values may be selected, such as values between about 0.10 Ohms to at least about 100 Ohms, and other distances may be selected, such as distances in the range of about 1 mm to at least about 25 mm. The resistance of the material  46  can be tuned by modifying properties of the material such as porosity and material type. For example, the material  46  can be made of insulating plastic (or other insulator) with carbon filler percent weights selected to tune the resistance of the cell. 
       FIG.  3    shows the device  40  in an inactive state, in which the conductor  50  is separated from the plate  44 . The device  40  is put into an active state by causing the conductor  50  to be in electrical contact with both plates  42  and  44 . In the active state, when voltage is applied, current flows through the conductor  50 , simulating a dendrite growing across a battery cell and causing a soft short. 
       FIG.  4    shows the device  40  in an active state. In this embodiment, the device  40  is put in the active state by compressing the material  46  so that the plates  42  and  44  are brought closer together to reduce the distance D (to a reduced distance D′) such that the second end  52  contacts the plate  44 . A testing device  60  may be connected to the plates  42  and  44  via respective leads  62  and  64 , to apply a voltage and measure the response of the device  40 , such as the change in current or voltage as compared to the inactive state. 
     The conductor  50  may have any desired length and/or configuration. In the example of  FIGS.  3  and  4   , the conductor is a wire mounted on the plate  42  and extending at least partially across the space  48 . Other lengths and/or configurations may be used. 
       FIG.  5    depicts an embodiment of the device  40  having another configuration of the conductor  50 . In this embodiment, the conductor  50  is a rigid length of metal extending into the space  48 . A thin sheet of insulating material  70  is attached to the material  46 , which simulates a separator (e.g., the separator  18 ). The conductor  50  has a sharp point  72  at the second end  52 , such that when the device  40  is compressed, the conductor  50  will poke through the insulating material  70  and contact the plate  44 , simulating a dendrite growing through the separator. 
     In some embodiments, the device  40  is activated by moving the end  52  of the conductor  50 , either in place of compression or in combination with compression. The end  52  may be moved using any desired mechanism. 
     Referring to  FIG.  6   , an embodiment of the device  40  includes an activation component  74  affixed at or near the end  52 . The activation component  74  includes, for example, a magnetic material or magnet. To activate the device  40  in this embodiment, a magnet can be positioned relative to the plate  44 , which attracts the activation component  74 , thereby pulling the end  52  into electrical contact with the plate  44 . 
     It is noted that any other suitable mechanism can be used to move the conductor  50  and/or the second end  52 , such as mechanical or hydraulic actuating devices. For example, the conductor  50  can be a spring that is held in a compressed position, and a mechanical release can be actuated to release the spring so that the second end  52  contacts the plate  44 . 
     The conductor  50  can be moved to transition the device from an inactive state to an active state, or to transition the device  40  from an active state to an inactive state. For example, the conductor  50  can be moved to put the conductor  50  in electrical contact with the plate  44  as discussed in conjunction with  FIG.  6   . Alternatively, the conductor  50  can be in electrical contact with both plates by default, and moved to separate an end of the conductor  50  from the plate  42  and/or  44  to deactivate the device  40 . 
     For example, the magnetic activation component  74  may be magnetically attractive to the second plate  44 . In an active state, the activation component  74  maintains electrical contact between the second end  52  and the plate  44 . The device  40  may be maintained in an inactive state by applying another magnet (not shown) or other suitable component to repel the activation component  74  and cause the second end  52  to separate from the plate  44 . The repelling component may be removed to activate the device  40 , so that the activation component  74  is no longer repelled and moves to the plate  44 . 
     In addition to providing a diffuse electrical path by the material  46 , or in place of providing a diffuse path, the material  46  may be configured to provide one or more directed current paths. For example, as shown in  FIG.  7   , one or more regions  76  extend within the material  46  from the plate  42  to the plate  44 . Each region  76  has a lower resistance than the resistance of the surrounding material  46 . The regions  76  may be included using any suitable method or process. For example, the material  46  may be made from a plastic or other insulating porous material, and the regions  76  can be portions of the material  46  impregnated with carbon or metallic particles, or layers deposited during additive manufacturing of the material  46 . 
       FIG.  8    depicts an embodiment of the simulation device  40 . In this embodiment, the material  46  includes multiple layers or sections. Portions of the conductor  50  are disposed between the sections, and the conductor  50  extends into the space  48  so that the ends  51  and  52  are not in contact with the plates  42  and  44 . The material  46  may be compressed to reduce the distance between the plates  42  such that the ends  51  and  52  are put into electrical contact with the plates  42  and  44 . 
     The device  40 , in some embodiments, includes multiple sets of plates, each of which includes the material  46 . A given set of plates may have one or more spaces  48  therebetween, or may have no spaces. 
       FIGS.  9  and  10    depict embodiments of a simulation device  80  that includes multiple sets of plates, and includes a conductive material  90  between each set of plates, which has a lower resistance than each set of plates and provides a diffuse or directed current path. The material  90  may be similar to the material  46  of  FIGS.  3 - 8   . The device  80  is shown in  FIGS.  9  and  10    in an active state. It is noted that properties of the material  90  may be the same across the sets of plates, or may be varied as desired (e.g., by varying thickness, material type, resistance, etc.). The simulation device  80  may have a single space  92  and an associated conductor  94  in the space ( FIG.  9   ), simulating a short at a given location, or may have more than one space  92 ,  98 ,  102  and associated conductor  94 ,  96 ,  100  ( FIG.  10   ) to simulate multiple shorts at various locations. The multiple sets of plates could, for example, simulate multiple unit cells such as those shown in  FIG.  1   . 
     The device  80  includes a first plate assembly  82  having three plates  82   a ,  82   b  and  82   c , which are each connected to a first tab  84 . A second plate assembly  86  includes two plates  86   a  and  86   b , which are connected to a second tab  88 . The first plate assembly  82  is made of copper and is configured to be negatively charged, and the second plate assembly  86  is made of aluminum and is configured to be positively charged. 
     A conductive foam or other material  90  is disposed between each set of plates. In  FIGS.  9  and  10   , four sets of plates are provided. A first set of plates includes plates  82   a  and  86   a , a second set of plates includes plates  86   a  and  82   b , a third set of plates includes plates  82   b  and  86   b , and a fourth set of plates includes plates  86   b  and  82   c . The conductive material  90  may be a compliant foam or other material and may be similar to the conductive material  46  of  FIGS.  3 - 8   . 
       FIG.  9    shows an embodiment having one space  92  and a conductor  94  disposed therein, simulating a short between plates  82   a  and 86a.  FIG.  10    illustrates how multiple shorts (or other conditions) can be simulated at various locations, and includes a space  98  and conductor  96  between plates  82   b  and  86   b , and a space  102  and conductor  100 . 
       FIG.  11    illustrates an embodiment of a method  120  of manufacturing a simulation device, simulating a battery cell, and/or detecting battery conditions or failure modes. Aspects of the method  120  may be performed by a processor or processors. It is noted the method  120  may be performed by any suitable processing device or system, or combination of processing devices. 
     The method  120  includes a number of steps or stages represented by blocks  121 - 125 . The method  120  is not limited to the number or order of steps therein, as some steps represented by blocks  121 - 125  may be performed in a different order than that described below, or fewer than all of the steps may be performed. 
     Aspects of the method are discussed in conjunction with the device  40  shown in  FIGS.  1  and  2   , for illustration purposes. The method  120  is not so limited and can be used with any type of simulation device, battery cell, etc. 
     At block  121 , the simulation device  40  is manufactured or assembled. For example, the material  46  is constructed using an additive manufacturing technique such as 3D printing. Resistivity of the material is controlled, for example, by selecting a material having a desired resistivity, or including a conductive material such as metal or carbon as an additive. The material could be, for example, printed from a conducting metal via metal 3D printing or processing of a plastic through a chemical reaction to create a copper or other metallic structure from the 3d printed material. The conductor  50  is attached (e.g., via welding or adhesive) and plates  42  and  44  are positioned and secured in contact with opposing sides of the material  46 . 
     The material  46  could be made in such a way that, under compression, a conductive additive such as carbon increases the conductivity of the material under pressure. This could be done via path planning and lattice optimization. 
     Printed material may be post processed to tune the electrical properties of the simulation device  40 . Post processing includes, for example deposition via sputtering or electro deposition to create conducting paths or regions (e.g., regions  76  shown in  FIG.  7   ). 
     At block  122 , the simulation device  40  is connected to a power source, such as a voltage supply. At block  123 , the device  40  is activated by electrically connecting the second end  52  of the conductor  50  to the plate  44 . This may be accomplished by deforming the material  46 , moving the conductor  50  or otherwise. Activation of the device causes a short circuit through the conductor  50 , simulating a soft short. 
     At block  124 , the response of the activated device  40  is measured. At block  125 , the response (e.g., voltage measurement, change in voltage) is correlated or otherwise associated with the failure mode. Subsequent testing and/or monitoring of actual battery cells may then be performed, for example, via a non-contact testing device. The testing device outputs signals from the battery, which may be analyzed to detect failure conditions. 
     The systems and methods described herein may be applicable to various types of batteries. In an embodiment, battery cells evaluated may be cells used in electric and/or hybrid vehicles; however, the systems and methods are not so limited. 
       FIG.  12    illustrates aspects of an embodiment of a computer system  140  that can perform various aspects of embodiments described herein. The computer system  140  includes at least one processing device  142 , which generally includes one or more processors for performing aspects of image acquisition and analysis methods described herein. Aspects of the computer system  140  may be incorporated into or connected to the testing device  60  or other device for measuring outputs from a simulation device. 
     Components of the computer system  140  include the processing device  142  (such as one or more processors or processing units), a memory  144 , and a bus  146  that couples various system components including the system memory  144  to the processing device  142 . The system memory  144  may include a variety of computer system readable media. Such media can be any available media that is accessible by the processing device  142 , and includes both volatile and non-volatile media, and removable and non-removable media. 
     For example, the system memory  144  includes a non-volatile memory  148  such as a hard drive, and may also include a volatile memory  150 , such as random access memory (RAM) and/or cache memory. The computer system  140  can further include other removable/non-removable, volatile/non-volatile computer system storage media. 
     The system memory  144  can include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out functions of the embodiments described herein. For example, the system memory  144  stores various program modules that generally carry out the functions and/or methodologies of embodiments described herein. A module or modules  152  may be included to perform functions related to acquiring measurements of the simulation device. An analysis module  154  may be included for processing of measurements and/or determining signatures associated with various failure modes. The system  140  is not so limited, as other modules may be included. As used herein, the term “module” refers to processing circuitry that may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. 
     The processing device  142  can also communicate with one or more external devices  156  as a keyboard, a pointing device, and/or any devices (e.g., network card, modem, etc.) that enable the processing device  142  to communicate with one or more other computing devices. Communication with various devices can occur via Input/Output (I/O) interfaces  164  and 165. 
     The processing device  142  may also communicate with one or more networks  166  such as a local area network (LAN), a general wide area network (WAN), a bus network and/or a public network (e.g., the Internet) via a network adapter  168 . It should be understood that although not shown, other hardware and/or software components may be used in conjunction with the computer system  40 . Examples include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, and data archival storage systems, etc. 
     While the above disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from its scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiments disclosed, but will include all embodiments falling within the scope thereof.