Abstract:
An automatic flushing mechanism includes an electronic control box containing a motor and an intermittent motion gear coupled to a rotation shaft of the motor. The intermittent motion gear is configured to rotate when the motor is operated. The intermittent motion gear includes a toothed portion including a plurality of gear teeth. The automatic flushing mechanism includes an intermittent motion pendulum rod including a first end pivotally attached to the electronic control box via a rotation shaft, a second end coupled to a flush valve, and a curved rack including a plurality of rack teeth which mesh with the gear teeth of the intermittent motion gear. Rotation of the intermittent motion gear causes the curved rack to be lifted upward, thereby rotating the intermittent motion pendulum rod about the rotation shaft and lifting the flush valve.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This application claims the benefit of and priority to Chinese Patent Application No. 201410127562.2 filed Mar. 31, 2014, the entirety of which is incorporated by reference herein. 
       BACKGROUND 
       [0002]    The present invention relates generally to smart bathroom products, and more particularly to an automatic flushing mechanism for a smart bathroom product such as an electronically actuated toilet. 
         [0003]    Some toilets include a tank which serves as a reservoir of flush water for the toilet. A flush valve is typically located at the bottom of the tank. The flush valve can be displaced via a flush actuating mechanism (e.g., a chain attached to a user-operable handle) to allow the flush water to flow through an opening covered by the flush value and into the base of the toilet. Automatic toilets may replace the user-operable handle with a motor or other automatic flush actuating mechanism. 
         [0004]    Some existing flush actuating mechanisms employ a turntable which is rotated in a circular motion. A traction chain generally connects the turntable to the flush valve. Due to the circular motion of the turntable, the traction chain may not move straight up and down during operation. For example, when the flush valve is in a closed position, the angle of the force applied by the traction chain may be oblique. The circular motion of the turntable may also cause the closing speed of the flush value to be slow. Such existing flush actuating mechanisms may be incapable of achieving a rapid closure of the flush value (similar to that achieved by manual operation), leading to the problem of water leakage as the flush valve cannot be closed tightly. 
       SUMMARY 
       [0005]    One implementation of the present disclosure is an automatic flushing mechanism for a toilet. The toilet includes a water tank and a flush valve configured to be lifted from a bottom of the water tank to release flush water from the water tank. The automatic flushing mechanism includes an electronic control box containing a motor and an intermittent motion gear coupled to a rotation shaft of the motor. The intermittent motion gear is configured to rotate when the motor is operated. The intermittent motion gear includes a toothed portion including a plurality of gear teeth. The automatic flushing mechanism includes an intermittent motion pendulum rod including a first end pivotally attached to the electronic control box via a rotation shaft, a second end coupled to the flush valve, and a curved rack including a plurality of rack teeth which mesh with the gear teeth of the intermittent motion gear. Rotation of the intermittent motion gear causes the curved rack to be lifted upward, thereby rotating the intermittent motion pendulum rod about the rotation shaft and lifting the flush valve. In some embodiments, the automatic flushing mechanism is located within the water tank. 
         [0006]    In some embodiments, the intermittent motion gear includes a smooth toothless root portion along a rim of the intermittent motion gear in series with the toothed portion. In some embodiments, a gap is formed between the smooth toothless root portion and the curved rack when the smooth toothless portion faces the curved rack. 
         [0007]    In some embodiments, the intermittent motion gear rotates through a cycle including a lifting phase and a falling phase. During the lifting phase, the toothed portion meshes with the curved rack and causes the curved rack to be lifted upward as the intermittent motion gear rotates. During the falling phase, the smooth toothless root portion faces toward the curved rack and the intermittent motion gear is separated from the curved rack, causing the curved rack to fall downward. 
         [0008]    In some embodiments, the intermittent motion gear includes a toothless top portion along a rim of the intermittent motion gear in series with the toothed portion. In some embodiments, distance from an outer edge of the toothless top portion to a center of the intermittent motion gear is greater than a distance from the rim of the intermittent motion gear to the center of the intermittent motion gear. In some embodiments, a bottom tooth of the curved rack remains in contact with and slides along the toothless top portion as the intermittent motion gear rotates after the bottom tooth disengages from the toothed portion. 
         [0009]    In some embodiments, the intermittent motion gear rotates through a cycle including a lifting phase and a holding phase. During the lifting phase, the toothed portion meshes with the curved rack and causes the curved rack to be lifted upward as the intermittent motion gear rotates. During the holding phase, the toothless top portion holds the curved rack in a lifted position. In some embodiments, the cycle further includes a falling phase during which the intermittent motion gear disengages from the curved rack, causing the curved rack to fall downward. 
         [0010]    In some embodiments, the intermittent motion gear rotates in a first rotational direction. The intermittent motion pendulum rod may initially rotate in a second rotational direction opposite the first rotational direction as the intermittent motion gear rotates in the first rotational direction. The intermittent motion pendulum rod may then switch to rotate in the first rotational direction as the intermittent motion gear continues to rotate in the first direction. 
         [0011]    Another implementation of the present disclosure is an automatic flushing mechanism. The automatic flushing mechanism includes an electric appliance control box containing a motor. The automatic flushing mechanism includes an intermittent motion gear including a toothed portion provided along a rim of the intermittent motion gear. The toothed portion includes at least one gear tooth. The intermittent motion gear is driven by the motor. The automatic flushing mechanism further includes an intermittent motion pendulum rod connected, on one end thereof, to a flush valve through a chain. The intermittent motion pendulum rod is connected, on another end thereof, to a rotation shaft which is fixed on the electric appliance control box. The intermittent motion pendulum rod is rotated around the rotation shaft and includes a curved rack which meshes with the toothed portion of the intermittent motion gear. 
         [0012]    In some embodiments, the intermittent motion pendulum rod is provided with a groove which contains the intermittent motion gear. The curved rack may be provided on one side of the groove. 
         [0013]    In some embodiments, the automatic flushing mechanism includes a position-limit device which is fixed on the electric appliance control box and limits movement of the intermittent motion pendulum rod. 
         [0014]    In some embodiments, the intermittent motion gear includes a smooth toothless root portion along the rim of the intermittent motion gear. In some embodiments, a gap is formed between the smooth toothless root portion and the curved rack. 
         [0015]    In some embodiments, the intermittent motion gear is rotated until the toothed portion meshes with the curved rack. A tooth top arc of a first gear tooth which the toothed portion adopts to mesh with the curved rack may be greater than a tooth top arc of any other gear tooth of the toothed portion. A tooth top arc of a second rack tooth which the curved rack adopts to mesh with the toothed portion may be greater than a tooth top arc of any other rack tooth of the curved rack. 
         [0016]    In some embodiments, the intermittent motion gear includes a smooth toothless top portion adjacent to the toothed portion along the rim of the intermittent motion gear. In some embodiments, a distance from an edge of the toothless top portion to a center of the intermittent motion gear is greater than a distance from the rim of the intermittent motion gear to center of the intermittent motion gear. In some embodiments, a bottom tooth of the curved rack remains in contact with and slides along the toothless top portion as the intermittent motion gear rotates after the bottom tooth disengages from the toothed portion. In some embodiments, the toothless top portion occupies between one-half and three-fourths of the rim of the intermittent motion gear 
         [0017]    Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined solely by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a structural diagram of a prior art flushing mechanism, according to an exemplary embodiment. 
           [0019]      FIG. 2  is a structural diagram of an automatic flushing mechanism of the present invention including an intermittent motion gear and an intermittent motion pendulum rod, according to an exemplary embodiment. 
           [0020]      FIG. 3  is a partially enlarged view of the intermittent motion gear and the intermittent motion pendulum rod of  FIG. 2 , according to an exemplary embodiment. 
           [0021]      FIG. 4  is another view of the intermittent motion gear and the intermittent motion pendulum rod of  FIG. 2 , showing the intermittent motion gear meshing with a curved rack of the intermittent motion pendulum rod, according to an exemplary embodiment. 
           [0022]      FIG. 5  is another view of the intermittent motion gear and the intermittent motion pendulum rod of  FIG. 2 , showing a toothless top portion of the intermittent motion gear supporting the curved rack and holding the intermittent motion pendulum rod in a raised position, according to an exemplary embodiment. 
           [0023]      FIG. 6  is another view of the intermittent motion gear and the intermittent motion pendulum rod of  FIG. 2 , showing a toothless root portion of the intermittent motion gear facing the curved rack, which allows the intermittent motion pendulum rod to drop into a closed position, according to an exemplary embodiment. 
           [0024]      FIG. 7  is a partially enlarged view of another embodiment of the intermittent motion gear and the intermittent motion pendulum rod, according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    Referring to  FIG. 1 , a drawing of a prior art flush actuating mechanism  10  is shown, according to an exemplary embodiment. Flush actuating mechanism  10  includes a turntable  11  and a traction chain  12  connecting turntable  11  to a flush valve  13  (e.g., a sealed float ball). In operation, turntable  11  rotates clockwise (as shown in  FIG. 1 ), which causes traction chain  12  to pull on flush valve  13  and displace flush valve  13  from a closed position. As turntable  11  continues to rotate past the central point, traction chain  12  relaxes and allows flush valve  13  to return to the closed position. The angle of the force applied by traction chain  12  to flush valve  13  is oblique, which prevents flush valve  13  from moving straight up and down. Further, the circular motion of turntable  11  causes the falling speed of flush valve  13  to be slow. Water leakage may occur as the flush valve  13  cannot be closed tightly. 
         [0026]    Referring now to  FIG. 2 , a structural diagram of an automatic flushing mechanism  20  of the present invention is shown, according to an exemplary embodiment. In some embodiments, automatic flushing mechanism  20  is located within the water storage tank of a toilet. Flushing mechanism  20  is shown to include a gearbox  21 , an intermittent motion gear  22 , and an intermittent motion pendulum rod  23 . In some embodiments, gearbox  21  is an electric appliance control mechanical reduction gearbox. For example, gearbox  21  may include a motor, an electric appliance control module, and/or a power supply unit. The power supply unit may receive power from an external power source or an internal power storage device. The electric appliance control module may include a wireless signal receiving unit (e.g., a sensor), a drive unit connected to the motor, and/or a trip switch. The power supply unit may supply power to the drive unit and the wireless signal receiving unit. The drive unit may be connected to the wireless signal receiving unit. The wireless signal receiving unit may receive an external wireless signal and may cause the drive unit to drive the motor in response to the wireless signal. 
         [0027]    In some embodiments, automatic flushing mechanism  20  is used in cooperation with an independent sensor trigger. The external wireless signal may be a signal that a user has finished using the toilet. For example, the wireless signal may be provided by a proximity sensor and/or motion sensor installed on or near the toilet. When a user finishes using the toilet, a signal may be sent automatically from the sensor. Alternatively, the signal may come from a button that is pressed by the user when the user finishes using the toilet. With a wireless signal, it is not necessary to connect automatic flushing mechanism  20  to the external button through a wire. Upon receiving the signal from the button and/or wireless sensor, the wireless signal receiving unit may cause the drive unit to operate (e.g., rotate), thereby triggering the flushing operation. In some embodiments, the motor rotates through one complete revolution when a flushing operation is triggered. 
         [0028]    Still referring to  FIG. 2 , intermittent motion gear  22  may be fixed to a rotating shaft of the motor and may rotate when the motor is operated. An end  27  of intermittent motion pendulum rod  23  may be connected to a flush valve (not shown) by a chain  24 . An opposite end  28  of intermittent motion pendulum rod  23  may be connected to a rotation shaft  25 . Rotation shaft  25  may be fixed to gearbox  21 . Intermittent motion pendulum rod  23  may be configured to rotate relative to gearbox  21  around rotation shaft  25 . The interaction between intermittent motion gear  22  and intermittent motion pendulum rod  23  may cause automatic flushing of the toilet, as described with reference to  FIGS. 3-7 . 
         [0029]    Referring now to  FIG. 3 , a partially enlarged view of intermittent motion gear  22  and intermittent motion pendulum rod  23  is shown, according to an exemplary embodiment. Intermittent motion gear  22  may be driven (i.e., rotated) by a motor contained within gearbox  21 . Intermittent motion gear  22  is shown to include a toothed portion  221  along a rim of intermittent motion gear  22 . Toothed portion  221  may include at least one gear tooth  2211 - 2212 . Intermittent motion pendulum rod  23  is shown to include a curved rack  231 . Curved rack  231  may include at least one rack tooth  2311 - 2312  and may be configured to mesh with toothed portion  221  of intermittent motion gear  22 . 
         [0030]    In operation, intermittent motion gear  22  is rotated in a counter-clockwise direction (as shown in  FIG. 3 ). When toothed portion  221  meshes with curved rack  231 , curved rack  231  is moved upward by the rotation of intermittent motion gear  22 . The upward motion of curved rack  231  causes intermittent motion pendulum rod  23  to rotate (e.g., in a clockwise direction as shown in  FIG. 3 ) around rotation shaft  25 . The rotation of intermittent motion pendulum rod  23  moves end  27  upward, which causes chain  24  to pull the flush valve upward. As intermittent motion gear  22  continues to rotate in the counter-clockwise direction, toothed portion  221  disengages from curved rack  231 . When toothed portion  221  disengages from curved rack  231 , intermittent pendulum rod  23  is no longer supported by the gear tooth meshing, which causes intermittent motion pendulum rod  23  to rapidly drop (e.g., rotate in a counter-clockwise direction around rotation shaft  25 ), thereby returning the flush valve to the closed position. 
         [0031]    Referring now to  FIGS. 4-6 , schematic diagrams illustrating the interaction between intermittent motion gear  22  and curved rack  231  are shown, according to an exemplary embodiment. From the perspective shown in  FIGS. 4-6 , intermittent motion gear  22  is rotated in a counter-clockwise direction. Toothed portion  221  meshes with curved rack  231  to drive intermittent motion pendulum rod  23  to be rotated around rotation shaft  25  in a clockwise direction. The rotation of intermittent motion pendulum rod  23  lifts intermittent motion pendulum rod  23  from the intermediate position shown in  FIG. 4  to the raised position shown in  FIG. 5 . Intermittent motion pendulum rod  23  is connected to chain  24 , which causes chain  24  to lift up the flush valve as intermittent motion pendulum rod  23  is raised. 
         [0032]    As intermittent motion pendulum rod  23  moves into the raised position (shown in  FIG. 5 ), intermittent motion gear  22  arrives at the bottom of curved rack  231 . As intermittent motion gear  22  continues to rotate in the counter-clockwise direction, toothed portion  221  becomes separated from curved rack  231 . Upon toothed portion  221  separating from curved rack  231 , intermittent motion pendulum rod  23  loses support and falls (e.g., rotates in the counter-clockwise direction around rotation shaft  25 ) from the raised position shown in  FIG. 5  to the closed position shown in  FIG. 6 . 
         [0033]    As intermittent motion pendulum rod  23  falls, chain  24  loses upward the pulling force provided by intermittent motion pendulum rod  23 , which causes the flush valve to rapidly fall (e.g., due to gravity) into a closed position at the bottom of the water tank. Advantageously, the impact force of falling facilitates complete closing of the flush valve and prevents leakage from occurring.  FIG. 6  shows the rotational position of intermittent motion gear  22  after intermittent motion pendulum rod  23  falls into the closed position. In the closed position, toothed portion  221  may be completely separated from curved rack  231 . 
         [0034]    Referring again to  FIG. 3 , intermittent motion gear  22  is shown to include a smooth toothless root portion  222  along a rim of intermittent motion gear  22 . In operation, intermittent motion gear  22  may rotate until toothless root portion  222  faces curved rack  231 . When toothless root portion  222  faces curved rack  231 , toothed portion  221  of intermittent motion gear  22  may be completely separated from curved rack  231 . In other embodiments, the separation between toothed portion  221  of intermittent motion gear  22  and curved rack  231  may be achieved in other ways. For instance, equipment may be provided to laterally move the motor, so that after intermittent motion gear  22  causes intermittent motion pendulum rod  23  to lift by a predetermined amount, the motor may be laterally moved to separate toothed portion  221  from curved rack  231 . However, the separation between toothed portion  221  and curved rack  231  provided by the present invention (e.g., by toothless root portion  222 ) may be smoother than any separation resulting from lateral motion of the motor and may be achieved without additional equipment required to effect such lateral motion. 
         [0035]    In some embodiments, a gap is provided between toothless root portion  222  and curved rack  231 . The gap between toothless root portion  222  and curved rack  231  may be described by the equation: L ME &gt;L R +L M , where L MR  is the total distance between the center of intermittent motion gear  22  and the center of rotation shaft  25 , L R  is the distance between the tooth top of curved rack  231  and the center of rotation shaft  25 , and L M  is the distance between toothless root portion  222  and the center of intermittent motion gear  22 . The difference between L MR  and L R +L M  represents the width of the gap. 
         [0036]    In some embodiments, intermittent motion gear  22  and curved rack  231  have a tooth pressure angle of approximately 25°˜45°. The standard tooth pressure angle may be approximately 20°. Since the standard tooth top is wide, a standard tooth may mesh without interference in normal operation. However, since intermittent motion gear  22  lacks teeth along its entire circumference, interference problems could potentially occur if the tooth top is too wide. To prevent any potential interference from occurring, the present invention may use a tooth pressure angle (e.g., approximately 25°˜45°) that is greater than the standard tooth pressure angle of approximately 20°. 
         [0037]    Still referring to  FIG. 3 , intermittent motion gear  22  is shown to include a first gear tooth  2211  and a plurality of other gear teeth  2212 . First gear tooth  2211  may be the first tooth of intermittent motion gear  22  to mesh with curved rack  231  when intermittent motion gear  22  is rotated in a counter-clockwise direction (as shown in  FIG. 3 ). In some embodiments, the tooth top arc (i.e., tip radius) of first gear tooth  2211  is greater than the tooth top arcs of the other gear teeth  2212 . For example, if intermittent motion gear  22  has a gear modulus of one (1), first gear tooth  2211  may have a tooth top arc within a range of approximately 0.4 to approximately 0.6. The other gear teeth  2212  may have tooth top arcs of approximately 0.35 or less. In other words, first gear tooth  2211  may have a sharper tip relative to the other gear teeth  2212 . 
         [0038]    Similarly, curved rack  231  is shown to include a second rack tooth  2311  and a plurality of other rack teeth  2312 . Second rack tooth  2311  may be configured to mesh between first gear tooth  2211  and the adjacent gear tooth  2212 . In some embodiments, the tooth top arc of second rack tooth  2311  is greater than the tooth top arcs of the other rack teeth  2312 . For example, second rack tooth  2311  may have a tooth top arc within a range of approximately 0.4 to approximately 0.6. The other rack teeth  2312  may have tooth top arcs of approximately 0.35 or less. In other words, second rack tooth  2311  may have a sharper tip relative to the other rack teeth  2312 . 
         [0039]    In some embodiments, the mesh between intermittent motion gear  22  and curved rack  231  is a flat top mesh. For example, intermittent motion gear  22  may include flat top teeth that are easily held out against each other when they move face to face. In some embodiments, the first gear tooth  2211  has a sharpened tooth top shape relative to the other gear teeth  2212  to ensure that intermittent motion gear  22  will achieve a smooth starting mesh with curved rack  231  and to prevent intermittent motion gear  22  from becoming stuck. These features may advantageously ensure a reliable starting mesh between toothed portion  221  and curved rack  231 . 
         [0040]    Still referring to  FIG. 3 , in some embodiments, intermittent motion gear  22  includes a smooth toothless top portion  223  along a rim of intermittent motion gear  22 . Smooth toothless top portion may be adjacent to toothed portion  221  and may follow toothed portion  221  as intermittent motion gear  22  is rotated relative to curved rack  231 . In some embodiments, the distance from the outer edge of toothless top portion  223  to the center of intermittent motion gear  22  is greater than the distance from the rim of intermittent motion gear  22  (i.e., the edge of toothless root portion  222 ) to the center of intermittent motion gear  22 . In other words, toothless top portion  223  may protrude from intermittent motion gear  22  relative to toothless root portion  222 . 
         [0041]    In operation, intermittent motion gear  22  may be driven by the motor (i.e., rotated) into the rotational position shown in  FIG. 5 . In the position shown in  FIG. 5 , toothed portion  221  is completely separated from curved rack  231  and toothless top portion  223  functions to support and position-limit intermittent motion pendulum rod  23 . In some embodiments, toothless top portion  223  supports the bottom tooth of rack teeth  2312 . Intermittent motion gear  22  may be rotated counter-clockwise through the position shown in  FIG. 5  and into the position shown in  FIG. 6 . As intermittent motion gear  22  is rotated, toothless top portion  223  may be separated from curved rack  231 , which causes intermittent motion pendulum rod  23  to fall down (i.e., rotate about rotation shaft  25 ) into the position shown in  FIG. 6 . 
         [0042]    Advantageously, the features provided by intermittent motion gear  22  and intermittent motion pendulum rod  23  simulate the functioning of a manually-operable handle. For example, toothless top portion  223  functions to hold intermittent motion pendulum rod  23  in the elevated position shown in  FIG. 5  as intermittent motion gear  22  continues to rotate after toothed portion  221  is separated from curved rack  231 . In some embodiments, intermittent motion pendulum rod  23  is held in the elevated position for the duration of a stopping time period T s . The stopping time period T s  may be defined by the equation T s =Range×T t , where Range is the percentage of the perimeter of intermittent motion gear that is covered by toothless top portion  223 , and T t  is the period of rotation for intermittent motion gear  22  (i.e., the time required for intermittent motion gear  22  to rotate through a complete circle). In some embodiments, the Range of toothless top gear  233  is approximately ½ to approximately ¾. By adjusting the Range of toothless top portion  223  along the perimeter of intermittent motion gear  22 , the stopping time period T s  can be adjusted, so as to meet different flushing water requirements (i.e., by increasing or decreasing the duration for which the flush valve is held open). 
         [0043]    In some embodiments, the last tooth of curved rack  231  (i.e., the bottom tooth of curved rack  231 ) continues to contact toothless top portion  223  after the mesh is disengaged. The last tooth of curved rack  231  may slide along toothless top portion  223  until the rotation of intermittent motion gear  22  separates the last tooth from toothless top portion  223 . As shown in  FIG. 5 , the last tooth of curved rack  231  may extend to form an arc  232  which contains the rotation of toothless top portion  233 . The last tooth of curved rack  231  may be the final tooth that meshes with toothed portion  221  before toothed portion  221  is separated from curved rack  231 . 
         [0044]    Referring again to  FIGS. 2-3 , intermittent motion pendulum rod  23  is shown to include a groove  230  which contains intermittent motion gear  22 . In some embodiments, curved rack  231  is located on one side of groove  230 . When intermittent motion pendulum rod  23  falls (e.g., rotates about rotation shaft  25 ) into the closed position shown in  FIG. 6 , intermittent motion gear  22  may engage groove  230 . Intermittent motion gear  22  supports groove  230  and thus stops the falling of intermittent motion pendulum rod  23 . Hence, groove  230  exerts a position-limit function while containing intermittent motion gear  22 . 
         [0045]    In some embodiments, automatic flushing mechanism  20  includes an additional position-limit device  26 . Position limiting device  26  may be fixed on gearbox  21  to limit the shaking and swinging of intermittent motion pendulum rod  23 . In some embodiments, position-limit device  26  is cross-connected on one side of intermittent motion pendulum rod  23 , and fixed to gearbox  21 . 
         [0046]    Referring now to  FIG. 7 , an alternative embodiment of intermittent motion pendulum rod  23  and intermittent motion gear  22  is shown. In the embodiment shown in  FIG. 7 , one side of intermittent motion pendulum rod  23  is used as curved rack  231 . Intermittent motion gear  22  and toothed portion  221  may be provided outside the intermittent motion pendulum rod  23  and positioned to mesh with curved rack  231 . 
         [0047]    The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.