Abstract:
A method for machining and finishing a metallic member to provide a finished product without any additional process uses a lathe and a milling process. A non-circular metallic member on a worktable is rotated, and lathe tool moved backwards and forwards to machine the peripheral top portion of the metallic member. The path of the lathe tool machines curved surfaces of the top portion of the metallic member. The rotation of the metallic member is then stopped, and a milling cutter is brought to meet the peripheral sidewall of the metallic member. The movement and feeding of the milling cutter is predetermined. The worktable rotates the metallic member to enable one end edge of the peripheral sidewall and then another to face the milling cutter, and have the end edge chamfered by the milling cutter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims all benefits accruing under 35 U.S.C. §119 from China Patent Application No. 201210553531.4, filed on Dec. 19, 2012, in the China Intellectual Property Office, the disclosure of which is incorporated herein by reference. The application is also related to co-pending applications entitled, “METHOD FOR MACHINING METALLIC MEMBER USING LATHING AND MILLING” (Atty. Docket No. US49872); “METHOD FOR MACHINING METALLIC MEMBER USING LATHING AND SCRAPING” (Atty. Docket No. US50024); “METHOD FOR MACHINING METALLIC MEMBER USING LATHING AND SCRAPING” (Atty. Docket No. US50025); “METHOD FOR MACHINING METALLIC MEMBER USING LATHING AND SCRAPING” (Atty. Docket No. US50026); “MACHINE TOOL WITH LATHE TOOL AND MILLING CUTTER” (Atty. Docket No. US50027); “MACHINE TOOL WITH LATHE TOOL AND SCRAPING CUTTER” (Atty. Docket No. US50028); “MACHINE CONTROL SYSTEM EMPLOYING LATHE TOOL AND MILLING CUTTER” (Atty. Docket No. US50030), “MACHINE CONTROL SYSTEM EMPLOYING LATHE TOOL AND SCRAPING CUTTER” (Atty. Docket No. US50031), “MILLING METHOD FOR MACHINING METALLIC MEMBER” (Atty. Docket No. US50033). 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure generally relates to methods for machining a metallic member, and particularly, to a method for machining member using lathing and milling. 
         [0004]    2. Description of the Related Art 
         [0005]    An electronic device such as a tabletop computer or a mobile phone may have a housing made of metal. The metallic housing includes a top portion and a peripheral sidewall extending from a peripheral edge of the top portion. The top portion has a greater surface area than that of the peripheral sidewall and has a non-circular flat surface or non-circular curved surface. The peripheral sidewall has four side surfaces arranged in order and adjacent two side surface connected by corners. In related manufacturing fields, if a milling process is employed to machine the metallic housing, some tracks occur on the top portion that has been a milled because of intermittent contact and interrupted milling by the milling cutter. Then a polishing process needs to be applied for a better appearance, thus the efficiency of the milling process is reduced. If a lathe process is adopted to machine the metallic member, it is difficult to machine a surface which is not circular. The lathe is not suitable to machine the peripheral sidewalls because of the four corners of the peripheral sidewall. Thus a number of additional machining processes must be added to machine the metallic housing. 
         [0006]    Therefore, there is room for improvement within the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0007]    The components in the drawings are not necessarily drawn to scale, the emphasis instead placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0008]      FIG. 1  is an isometric view of a first embodiment of a machine equipped with a lathe feeding mechanism and a milling feeding mechanism, and a worktable. 
           [0009]      FIG. 2  is an exploded, isometric view of the machine of  FIG. 1 . 
           [0010]      FIG. 3  is a partial, exploded, isometric view of the lathe feeding mechanism and the milling feeding mechanism of  FIG. 2 . 
           [0011]      FIG. 4  is an exploded, isometric view of the lathe feeding mechanism of  FIG. 3 . 
           [0012]      FIG. 5  is an isometric view of a metallic member to be machined. 
           [0013]      FIG. 6  is a sectional view of the metallic member of  FIG. 5 , taken along line VI-VI of  FIG. 5 . 
           [0014]      FIG. 7  is a flow chart of a first embodiment of the method for machining the metallic member. 
           [0015]      FIG. 8  is a schematic view of a second embodiment of the machine with a part removed. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]      FIGS. 1 and 2  show a first embodiment of a machine  100  adopting a milling method for machining a metallic member  300  (see  FIG. 5 ). The machine  100  includes a machine support  10 , a worktable  20 , a moving device  30 , a lathe feeding mechanism  40 , a milling feeding mechanism  50 , and a controller  60 . The worktable  20  holds a workpiece in place and is supported by the machine support  10 . The moving device  30  is movably positioned on the machine support  10  above the worktable  20 . The lathe feeding mechanism  40  and the milling feeding mechanism  50  are arranged side by side and slidably mounted on the moving device  30 . The controller  60  is electrically connected to the worktable  20 , the moving device  30 , the lathe feeding mechanism  40 , and the milling feeding mechanism  50  for controlling the machine  100 . Under the control of the controller  60 , the moving device  30  can be driven to move with the lathe feeding mechanism  40  and the milling feeding mechanism  50 , such that the lathe feeding mechanism  40  and the milling feeding mechanism  50  can be driven three-dimensionally along Cartesian coordinates, that is, along the X, the Y, and the Z axes. 
         [0017]    The machine support  10  includes a base  11  and a pair of support bodies  13  positioned on the base  11 . The pair of support bodies  13  is parallel to each other and arranged apart from each other. Each support body  13  includes a first sliding rail  131  on a surface away from the base  11 . In the illustrated embodiment, the first sliding rail  131  extends substantially parallel to the X-axis (a first direction). 
         [0018]    The worktable  20  is rotatably positioned on the base  11  between the two support bodies  13 . The worktable  20  includes a pair of mounting bases  21 , a first rotating member  23 , a rotating shaft  25 , and a second rotating member  27 . The pair of mounting bases  21  is located in the middle portion of the base  11 , in parallel. The pair of mounting bases  21  is located between the two support bodies  13 . The first rotating member  23  is mounted on one mounting base  21 . The rotating shaft  25  interconnects the first rotating member  23  and the other one mounting base  21 . The first rotating member  23  is capable of rotating the rotating shaft  25  around an α axis. The α axis is parallel to the Y-axis but is not co-linear (a second direction). The second rotating member  27  is positioned on a middle portion of the rotating shaft  25 , and capable of rotating the metallic member  300  placed thereupon around an β axis. The β axis is parallel to the Z-axis (a third direction) but is not co-linear. The first rotating member  23  and the second rotating member  27  are electrically connected to the controller  60 . In the illustrated embodiment, the first rotating member  23  and the second rotating member  27  are direct drive motors. 
         [0019]    The moving device  30  is slidably mounted on the pair of support bodies  13  and located above the worktable  20 . The moving device  30  includes a cross beam  31 , a pair of sliding bases  33 , a pair of first driving mechanisms  35 , and a second driving mechanism  37 . The extending direction of the cross beam  31  is substantially parallel to the Y-axis. Opposite ends of the cross beam  31  are slidably positioned on the support bodies  13 . The cross beam  31  includes a pair of second sliding rails  311  positioned on a side surface thereof and extending substantially parallel to the Y-axis. The pair of sliding bases  33  is installed on the opposite ends of the cross beam  31  to slidably connect with the first sliding rail  131 . The first driving mechanism  35  is mounted on a surface of the sliding base  33  away from the cross beam  31  and located adjacent to an end of the first sliding rail  131 . The pair of first driving mechanisms  35  is employed to drive the cross beam  31  to move along the X-axis direction. 
         [0020]    The second driving mechanism  37  is mounted on the cross beams  31  to drive the lathe feeding mechanism  40  and the milling feeding mechanism  50  to move along the second sliding rails  311 . The first driving mechanism  35  and the second driving mechanism  37  are electrically connected to the controller  60 . In the illustrated embodiment, the first driving mechanisms  35  and the second driving mechanism  37  are linear motors with wonderful performance. In other embodiments, the first driving mechanisms  35  and the second driving mechanism  37  may be other drivers, such as hydraulic cylinders or rams. The number of the first driving mechanisms  35 , and the second driving mechanism  37  may be set according to the application. 
         [0021]      FIGS. 3 to 4  show the lathe feeding mechanism  40  slidably positioned on the cross beams  31 . The lathe feeding mechanism  40  includes a sliding saddle  41  (see  FIG. 2 ), a mounting seat  43 , a tool holder  45 , a pair of feeding assemblies  47 , and a lathe tool  49 . The sliding saddle  41  is assembled to the cross beams  31  and movably engages with the pair of second sliding rails  311 . The sliding saddle  41  is driven by the second driving mechanism  37  to slide along the Y-axis direction together with the lathe feeding mechanism  40  and the milling feeding mechanism  50 . The mounting seat  43  is fitted to the sliding saddle  41  away from the cross beam  31  and equipped with four guiding rails  413  extending along the Z-axis direction. The four guiding rails  413  are divided in two sets spaced from each other in pairs. The sliding saddle  41  further includes a mounting block  415  adjacent to the base  11 . The mounting block  415  is located between the two sets of guiding rails  413 . The mounting seat  43  is assembled to the sliding saddle  41  and spaced from the four guiding rails  413 . 
         [0022]    The mounting seat  43  includes a frame  431  and two mounting boards  433  assembled to opposite sides of the frame  431 . The frame  431  includes a first side wall  4311  and a second side wall  4313 . The first side wall  4311  and the second side wall  4313  are positioned substantially parallel to each other and cooperatively define a receiving space  4315 . The first side wall  4311  is slidably connected with the sliding saddle  41 . Two separate guiding portions  4317  protrude from an inner surface of the first side wall  4311  facing toward the second side wall  4315  and extending substantially parallel to the Z-axis. A through groove  4318  is defined in the second side wall  4313  and extends along a direction substantially parallel to the Z-axis corresponding to the guiding portions  4317 . Two sliding portions  4319  protrude from an outer surface of the second side wall  4313  at two sides of the through groove  4318 . In the illustrated embodiment, the sliding portions  4319  are sliding rails, and the frame  431  is integrally formed. The two mounting boards  433  are installed on opening sides of the frame  431 . Each mounting board  433  is connected substantially perpendicularly to the first wall  4311  and the second side wall  4313  to close the two opening sides of the frame  431 . 
         [0023]    The tool holder  45  slidably connects with the mounting seat  43 . The tool holder  45  is substantially “T” shaped, and includes a main body  451  and a sliding board  453  protruding substantially perpendicularly from the main body  451 . The main body  451  is a bar of material tapering at both ends, and positioned outside of the mounting seat  43 . Two distanced holding portions  4511  are positioned on a surface of the main body  451  facing the sliding board  453 . The two holding portions  4511  slidably engage with the pair of sliding portions  4319  of the mounting seat  43 . The sliding board  453  passes through the through groove  4318  and is slidably assembled to the two guiding portions  4317 , dividing the receiving space  4315  into two parts. 
         [0024]    The pair of feeding assemblies  47  is mounted in the mounting seat  43 , and includes two drivers  471  electrically connected to the controller  60 . The two drivers  471  are capable of driving the tool holder  45  into reciprocating motion at high speed along the direction of the Z-axis, relative to the guiding portions  4317  and the sliding portions  4319 . The two drivers  471  are received in the receiving space  4315  and positioned on two sides of the sliding board  453 . In the illustrated embodiment, the drivers  471  are linear motors. Each driver  471  includes a forcer  4711  and a stator  4713 . Each forcer  4711  is fixed to a surface of each of the mounting boards  433 . The sliding board  453  is positioned between the two forcers  4711 . The two stators  4713  are positioned on the opposite surfaces of the sliding board  453 . In other embodiments, the number of drivers  471  may be set according to application. For example, the two drivers  471  can replace a more powerful single driver, or three or more drivers can be positioned to drive the tool holder  45  to maximize the available power, and the assembly of the drivers is simpler. 
         [0025]    The lathe tool  49  is fixedly assembled to the main body  451  of the tool holder  4511  adjacent to the base  11 . 
         [0026]    The milling feeding mechanism  50  includes a linear driving assembly  53 , a linking board  54 , a rotatable driving member  55  and a milling cutter  57 . The linear driving assembly  53  includes a driving member  531 , a screw leading rod  533 , and a nut  535 . The driving member  531  is mounted on the sliding saddle  43  above the cross beam  31 . The screw leading rod  533  interconnects the driving member  531  and the mounting block  415 . The nut  535  is sleeved on the screw leading rod  533  and engages with the screw leading rod  533 . The linking board  54  is slidably assembled to the two sets of guiding rails  413  and fixed to the nut  535 . The rotatable driving member  55  is assembled to a side surface of the linking board  54  opposite to the screw leading rod  533 . The milling cutter  57  is mounted on an end of the rotatable driving member  55  adjacent to the base  11 . 
         [0027]    The driving member  531  is capable of rotating the screw leading rod  533  and drives the linking board  54 , the rotatable driving member  55 , and the milling cutter  57  to slide along Z-axis direction. The rotatable driving member  55  is capable of rotating the milling cutter  57  against the metallic member  300 . The milling cutter  57  is driven by the cross beam  31  to move along the X-axis direction or the Y-axis direction, and driven by the linear driving assembly  53  to move along Z-axis direction. 
         [0028]    In assembly, the worktable  20  is positioned between the two support bodies  13 . The cross beam  31  is installed on the two support bodies  13  via the pair of sliding bases  33 . The pair of first driving mechanisms  35 , and the second driving mechanism  37  are mounted on the base  11  and the cross beam  31  respectively. The lathe feeding mechanism  40  and the milling feeding mechanism  50  are mounted to the cross beam  31  side by side. The worktable  20 , the moving device  30 , the lathe feeding mechanism  40 , and the milling feeding mechanism  50  are electrically connected to the controller  60 . 
         [0029]    Referring to  FIGS. 5 and 6 , the metallic member  300  to be machined is a housing of a tablet computer or a mobile phone. The metallic member  300  is substantially rectangular, and includes a top portion  301  and a peripheral sidewall  303  extending from a peripheral edge of the top portion  301 . The top portion  301  has a curved surface with a relatively greater surface area than that of the peripheral sidewall  303 . In the embodiment, the peripheral sidewall  303  has four side surfaces  3031  arranged in order and every two of the adjacent side surfaces  3031  are connected by a corner  3033 . The four side surfaces  3031  are substantially flat surfaces, each corner  3033  interconnects two adjacent side surfaces  3031 . The peripheral sidewall  303  further includes an end edge  305  away from the top portion  301 . 
         [0030]    Referring to  FIG. 7 , an embodiment of a method for machining the metallic member includes steps as follows: 
         [0031]    In step S 101 : a machine  100  is provided, the machine  100  includes a worktable  20 , a lathe feeding mechanism  40 , and a milling feeding mechanism  50 , the lathe feeding mechanism  40  includes a lathe tool  49 , and the milling feeding mechanism  50  includes a milling cutter  57 . In the embodiment, the machine  100  is provided as previously described. 
         [0032]    In step S 102 : a metallic member  300  is placed and held on the worktable  20  of the machine  100 . The metallic member  300  includes a top portion  301  and a peripheral sidewall  303  extending from a peripheral edge of the top portion  301 , the peripheral sidewall  303  includes an end edge  305  away from the top portion  301 . 
         [0033]    In step S 103 : the worktable  20  drives the metallic member  300  to rotate. In the embodiment, the metallic member  300  is driven by the second rotating member  27  to rotate around the β axis; 
         [0034]    In step S 104 : the lathe feeding mechanism  40  drives the lathe tool  49  to machine the top portion  301  of the metallic member  300  with a high frequency reciprocating motion. In detail, firstly, the pair of first driving mechanisms  35  drives the cross beam  31  to slide along the X-axis, until the lathe tool  49  arrives at an end of a side of the top portion  31 . The second driving mechanism  37  drives the lathe feeding mechanism  40  to move along the Y-axis, until the lathe tool  49  arrives at a middle of the side of the top portion  31 , the lathe tool  49  the reaching an original position above the worktable  20  for machining Finally, the pair of feeding assemblies  47  drives the lathe tool  49  to move backwards and forwards at a high speed along the Z-axis according to the depth of cutting required for each machining portion of the top portion  301 , to machine the rotary metallic member  300  circumferentially. 
         [0035]    In step S 105 : the lathe feeding mechanism  40  moves along a predetermined path relative to the worktable  20 . The first driving mechanism  25  drives the feeding mechanism  40  to move along the X-axis via the cross beam  31 , such that the rotary lathe tool  49  moves radially across the rotary metallic member  300  for machining curved surfaces on the top portion  301 , until the lathe tool  49  arrives at a rotational center of the metallic member  300 . 
         [0036]    In step S 106 : the worktable  20  stops the metallic member  300  rotating, and the lathe tool  49  moves away from the metallic member  300 . That is, the second rotating member  27  stops the rotating motion, to hold the metallic member  300  still, and the lathe feeding mechanism  40  drives the lathe tool  49  to leave the worktable  20 . 
         [0037]    In step S 107 : the milling feeding mechanism  50  drives the milling cutter  57  to rotate and contact the peripheral sidewall  303  of the metallic member  300 . In detail, firstly, the pair of first driving mechanisms  35  drives the cross beam  31  to slide along the X-axis, and the second driving mechanism  37  drives the lathe feeding mechanism  40  to move along the Y-axis, such that the milling cutter  57  moves toward one first sliding rail  131  and arrives at a position above an end of one side surface  3031  of the peripheral sidewall  303 . Secondly, the rotatable driving member  55  drives the milling cutter  57  to rotate. Finally, the linear driving assembly  53  drives the milling cutter  57  to slide along the two sets of guiding rails  413  until the milling cutter  57  meets the peripheral sidewall  303  of the metallic member  300 . 
         [0038]    In step S 108 : the milling feeding mechanism  50  moves along a predetermined path and controls a feed of the milling cutter  57  relative to the metallic member  300 . In detail, the pair of first driving mechanisms  35  drives cross beam  31  to slide along the X-axis to enable the milling cutter  57  to mill the one side surface  3031  of the peripheral sidewall  303 . When milling of the side surface  3031  is finished, the milling cutter  57  arrives at the corner  3033 . At this time, the second rotating member  27  rotates the metallic member  300  around the β axis until a side surface  3031  which is adjacent to the milled side surface  3031  is rotated to milling cutter  57  and arranged parallel to the first sliding rail  131 . 
         [0039]    In the rotating process, the milling cutter  57  is driven by the pairs of the first driving mechanisms  35  and the second driving mechanisms  37  to change position relative to the metallic member  300 , and the milling cutter  57  machines the corner  3033  during the rotation. When the next side surface  3031  of the peripheral sidewall  303  is rotated to a position parallel to the pair of first sliding rail  131 , the pair of first driving mechanisms  35  drives the cross beam  31  to slide along the X-axis to enable the milling cutter  57  to mill the next side surface  3031 . During the milling, feeding mechanism  50  moves along the predetermined path, the rotatable driving member  55  controls a feed of the milling cutter  57  relative to the metallic member  300  along the Z-axis direction. In another embodiment, the metallic member  300  is fully fixed, thus when the milling cutter  57  arrives at the corner  3033 , it is driven by the pairs of the first driving mechanisms  35  and the second driving mechanisms  37  to change position relative to the metallic member  300 . During the rotating process, the milling cutter  59  machines the corner  3033  until it arrives at the next side surface  3031  of the metallic member  300 . Then the milling cutter  57  mills the next side surface  3031  of the peripheral sidewall  303  by a similar process. 
         [0040]    In step S 109 : the worktable  20  rotates the metallic member  300  to enable the end edge  305  of the peripheral sidewall  303  to face the milling cutter  57 , the milling feeding mechanism  50  chamfers the end edge  305  along a predetermined path and controls a feed of the milling cutter  57  relative to the metallic member  300 . In detail, the first rotating member  23  rotates the metallic member  300  along the α axis upward to enable the end edge  305  on one side surface  3031  to face the milling cutter  57 , the milling feeding mechanism  50  chamfers the end edge  305 . When finishing chamfering the end edge  305  on one side surface  3031 , the first rotating member  23  rotates the metallic member  300  along the α axis downward, the second rotating member  27  rotates the metallic member  300  along the β axis to change position of the metallic member  300  relative to the milling cutter  57 , until the milling cutter  57  arrives at a side surface  3031  adjacent to the side surface  3031  which has the milled end edge  305 , then the first rotating member  23  rotates the metallic member  300  along the α axis upward to enable the end edge  305  on the next side surface  3031  to face the milling cutter  57 , such that the milling cutter  57  chamfers the end edge  305  without interruption and with no intermittent contact. A third rotating member  29  may be employed to rotate the metallic member  300  along a γ axis perpendicular to the α and the β axis, the γ axis is parallel to the third direction. The first rotating member  21  is assembled to the third rotating member  29 . When chamfering, the first rotating member  23  rotates the metallic member  300  along the α axis upward to enable the end edge  305  on one side surface  3031  to face the milling cutter  57 , the milling feeding mechanism  50  chamfers the end edge  305 , and when finishing the chamfering of the end edge  305  on one side surface  3031 , the first rotating member  23  rotates the metallic member  300  along the α axis downward, then the milling cutter  57  moves to a next side surface  3031 , the third rotating member  29  rotates the metallic member  300  along the γ axis to change position of the metallic member  300  relative to the milling cutter  57 , until the end edge  305  on the adjacent surface  3031  faces the milling cutter  57 , then the milling feeding mechanism  50  is able to chamfer the end edge  305  on the next side surface  3031 . In the embodiment, the metallic member  300  does not need to rotate along the β axis. The worktable  20  drives the metallic member  300  to rotate, for presentation to the milling cutter  57  for machining other portions of the metallic member  300 . 
         [0041]    When only the peripheral sidewall  303  of the metallic member  300  needs to be machined, step  103  to step  106  may be omitted. The milling feeding mechanism  50  chamfers the end edge  305  of the metallic member  300  firstly and then carries out milling of the peripheral sidewall  303 . 
         [0042]    Referring to  FIG. 8 , a second embodiment of machine  200  is employed in a second embodiment of method for machining the metallic member  300 . The machine  200  is similar to the machine  100  in structure, save that a sliding saddle  41   a  is slidably assembled to a cross beam  31   a,  and a second rotating member  27   a  is mounted on a rotating shaft  25   a.  The metallic member  300  is placed and held on the second rotating member  27   a.  The difference between the machines  100 / 200  is that, a mounting seat  43   a  of the machine  200  is slidably mounted on the sliding saddle  41   a  and capable of sliding along the Z 1 -axis direction relative to the sliding saddle  41   a,  and a lathe tool  49  is slidably mounted on the mounting seat  43   a.    
         [0043]    When the lathe feeding mechanism  40  is to machine the top portion  301  of the metallic member  300 , the pair of first driving mechanisms  35  drive the cross beam  31  to slide along the X-axis, and the second driving mechanism  37  drives the lathe feeding mechanism  40  to move along the Y-axis, such that the lathe tool  49  arrives at an original position above the worktable  20  for machining The original position is located at a middle of a side of the top portion  301 . Then the mounting seat  43   a  drives the lathe tool  49  to move downwardly along the Z 1 -axis to reach a preset position near the metallic member  300 . Finally, the pair of feeding assemblies  47  drives the lathe tool  49  to move backwards and forwards at a high speed along the Z-axis according to the depth of cutting required for each machining portion of the top portion  301 , to machine the rotary metallic member  300  circumferentially. Because the mounting seat  43   a  can slide along the Z 1 -axis to place the lathe tool  49  at the preset position, a reciprocating distance of movement of the lathe tool  49  relative to the metallic member  300  can be reduced, thereby enhancing a reaction response of the lathe tool  49 . 
         [0044]    Accordingly, in the second embodiment of the method for machining the metallic member  300 , after driving the cross beam  31  to slide along the Y-axis by the second driving mechanisms  37 , a sub-step of moving the mounting seat  43   a  downward along the Z 1 -axis direction to reach a preset position is interposed. 
         [0045]    The milling feeding mechanism  50  mills the peripheral sidewall  303  and chamfers the end edge  305  of the metallic member  300  before the lathe feeding mechanism  40  machines the top portion  301 . The milling feeding mechanism  50  is not assembled to the sliding saddle  41 , but is assembled to a sliding plate (not shown) slidably mounted on the pair of second guiding rails  311 , such that the lathe feeding mechanism  40  and the milling feeding mechanism  50  may be controlled independently. 
         [0046]    While the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure, as defined by the appended claims.