Patent Publication Number: US-2023148804-A1

Title: Self-Lifting Toilet Seat

Description:
PRIORITY 
     This patent application claims priority from provisional U.S. patent application No. 63/279,646, filed Nov. 15, 2021, provisional U.S. patent application No. 63/303,171, filed Jan. 26, 2022, provisional U.S. patent application No. 63/325,523, filed Mar. 30, 2022, and provisional U.S. patent application No. 63/395,168, filed Aug. 4, 2022, the disclosures of which are incorporated herein, in their entireties, by reference. 
    
    
     FIELD OF THE INVENTION 
     Illustrative embodiments generally relate to toilet seats and, more particularly, illustrative embodiments relate to self-lifting toilet seats. 
     BACKGROUND OF THE INVENTION 
     Toilet seats in public restrooms are frequently soiled, particularly in male and gender-neutral restrooms because men often urinate standing up while the toilet seat is in the down position. Soiling of toilet seats can also occur in female restrooms. Because restroom facilities do not belong to the users, people often have little consideration for the messes they cause. This means that users are less likely to lift the seat up before use, more likely to make messes, and less likely to clean up after themselves if they do make a mess. Conversely, in the home, users of a toilet seat often lift the seat to urinate, only to forget to lower it after use. 
     SUMMARY OF VARIOUS EMBODIMENTS 
     In accordance with one embodiment of the invention, a self-lifting toilet seat system includes a toilet seat configured to be sat upon by a user. The system has a hinge configured to rotatably couple the toilet seat and a toilet bowl. The hinge is configured so that the toilet seat is transitionable from an up position to a down position. A lifting system is configured to raise the toilet seat towards the up position. A sealed hinge housing has at least a portion of a delay system therein. The delay system is configured to cause a time delay before the lifting system causes the toilet seat to self-lift towards the up position. The delay system is configured so that the time delay begins after removal of a threshold downward force on the toilet seat. 
     In various embodiments, the time delay is reset upon application of the threshold downward force on the toilet seat. The time delay may be paused upon the application of the threshold downward force on the toilet seat. The threshold downward force may be applied by a user sitting on the toilet seat or pushing the seat down. In various embodiments, the lifting system comprises a spring. 
     Among other things, the delay system may include a suction cup and an attachment surface. The temporary adhesion of the cup to the attachment surface delays the toilet seat from self-lifting to the up position. To that end, the attachment surface may include one or more controlled leakage channels. The suction cup may be configured to overlap with at least a portion of the controlled leakage channel when the user lowers the toilet seat to the down position. The one or more controlled leakage channels may be configured to be positioned to be under the suction cup when the suction cup is adhered to the attachment surface. 
     The one or more of the controlled leakage channels may be sealed by a porous film restricting fluid flow into the suction cup. The attachment surface may be fluid permeable. Thus, the time delay may be a function of the rate of fluid influx while the suction cup is adhered. Additionally, or alternatively, the suction cup elastomer may fluid permeable. Accordingly, the time delay may be a function of the rate of influx of fluid while the suction cup is adhered to the attachment surface. In various embodiments, the suction cup is coupled with the toilet seat through a linkage. The system may be configured to so the time delay is between about 1 second and about 5 minutes. 
     The hinge housing may be sealed. For example, the housing may be substantially sealed against external sources of contamination. The wall of the substantially sealed housing may contain a filter permeable to air and configured to trap or block contaminates. Among other things, the delay mechanism may be sealed in the housing of the hinge. 
     The delay system may be sealed in the toilet seat. The delay system may include one or more material flow loops that are internal to and fully contained within the seat. Various embodiments may have a quantity of material (e.g., liquid) within the one or more internal material flow loops. Furthermore, embodiments may include a material motion restricting element within each of the one or more material flow loops. The time delay may be a function of the material restricting element. Additionally, or alternatively, some embodiments may include a geared delay system that controls the time delay. Accordingly, various embodiments provide a passive lifting system and delay system, requiring no electronic power. 
     In accordance with another embodiment, a method automatically self-lifts a toilet seat. The method provides a toilet seat. The seat is configured to couple with a hinge that rotatably couples the toilet seat and a toilet bowl. The hinge is configured so that the toilet seat is transitionable from an up position to a down position. The method lowers the toilet seat to a down position. Lowering the toilet seat engages a substantially sealed delay system configured to cause a time delay before the toilet seat self-lifts. The toilet seat is self-lifted after the time delay using the lifting system. 
     In some embodiments, the method lowers the toilet seat to the down state, from any location of the seat about the hinge, to restart or pause the time delay. The delay system may include a suction cup and an attachment surface, and lowering the toilet seat to a down position causes the suction cup to couple with the attachment surface. Furthermore, the controlled admission of fluid into the suction cup may release the cup from the attachment surface. The toilet seat may then be self-lifted using a lifting device. 
     In accordance with yet another embodiment, a self-lowering toilet seat system includes a toilet seat configured to be sat upon by a user. The system includes a hinge rotatably coupling the toilet seat and a toilet bowl. The hinge is configured so that the toilet seat is transitionable between a down position and an up position. A lowering device is configured to self-lower the toilet seat towards the down position. The system includes a housing having a mechanical delay system therein. The delay system is configured to cause a time delay before the lowering device causes the toilet seat to lower towards the down position. The delay system is trigged by a user raising the toilet seat towards the up state and removing their applied force from the toilet seat. The system is further configured to restart the delay system if the user re-applies the raising force before the delay system has expired. 
     In various embodiments, the system is configured to restart when the user applies the raising force to lift the seat to an up state. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Those skilled in the art should more fully appreciate advantages of various embodiments of the invention from the following “Description of Illustrative Embodiments,” discussed with reference to the drawings summarized immediately below. 
         FIG.  1    schematically shows a public restroom in accordance with illustrative embodiments of the invention. 
         FIG.  2    schematically shows the toilet seat transitioning from an up position to a down position in accordance with illustrative embodiments. 
         FIGS.  3 A- 3 C  schematically show the self-lifting toilet seat system in accordance with illustrative embodiments. 
         FIG.  4 A  schematically shows a close-up view of the portion of the toilet seat adjacent to the hinge housing in accordance with illustrative embodiments of the invention. 
         FIG.  4 B  schematically shows a perspective view of  FIG.  4 A . 
         FIGS.  5 A- 5 B  schematically show the hinge of  FIG.  4 A . 
         FIG.  6 A  schematically shows a cutaway side view of the toilet seat of  FIG.  5 A  in the up position in accordance with illustrative embodiments. 
         FIG.  6 B  schematically shows a cutaway side view of the toilet seat of  FIG.  5 A  in the neutral state in accordance with illustrative embodiments. 
         FIG.  6 C  schematically shows a cutaway side view of the toilet seat of  FIG.  5 A  in the down state in accordance with illustrative embodiments. 
         FIGS.  7 A- 7 B  schematically show a side view of the biasing system in accordance with illustrative embodiments of the invention. 
         FIG.  8    schematically shows a cutaway view of the delay system in accordance with illustrative embodiments. 
         FIG.  9 A  schematically shows an embodiment of the timing plate in accordance with illustrative embodiments. 
         FIGS.  9 B- 9 C  schematically show alternative embodiments of the timing plate with included quick release channels 
         FIG.  9 D  schematically shows an alternative embodiment of the timing plate with a groove 
         FIG.  10    schematically shows the associated torque profiles of the system and seat in accordance with illustrative embodiments 
         FIG.  11 A  schematically shows a top view of an alternative embodiment of the self-lifting and delay system in accordance with illustrative embodiments. 
         FIGS.  11 B-C  schematically show a perspective view of the device of  FIG.  11 A  in the up position and down position, respectively. 
         FIG.  11 D  schematically shows a perspective view of the delay system of the device of  FIG.  11 A . 
         FIGS.  12 A- 12 B  schematically show an alternative embodiment of the delay system in the up position and down position, respectively. 
         FIG.  13    schematically shows an alternative embodiment of the delay system in accordance with illustrative embodiments. 
         FIG.  14    shows a method of self-lifting a toilet seat in accordance with illustrative embodiments of the invention. 
         FIG.  15    shows a method of self-lowering a toilet seat in accordance with illustrative embodiments of the invention. 
         FIG.  16 A-C  schematically shows the seat of the lifting system in various positions in accordance with illustrative embodiments. 
         FIG.  17    schematically shows an alternative embodiment of the torque profiles of the seat vs the lifting system in accordance with illustrative embodiments of the invention. 
         FIG.  18    schematically shows an alternative embodiment of the lifting system in accordance with illustrative embodiments. 
         FIG.  19    schematically shows the torque sharing scheme in accordance with illustrative embodiments. 
         FIG.  20    schematically shows a partially exposed view of the delay system gearing rotatably coupled to the lifting system of  FIG.  18   . 
         FIG.  21    schematically shows a first planetary gearing set in accordance with illustrative embodiments. 
         FIG.  22    schematically shows a second planetary gearing increase in accordance with illustrative embodiments. 
         FIG.  23    schematically shows a planetary gearing increase and targeted disengagement mechanism in accordance with illustrative embodiments. 
         FIG.  24 A  schematically shows the gears when the seat is in the up position in accordance with illustrative embodiments. 
         FIG.  24 B  schematically shows the main spring unit in initial engagement iu with a booster spring unit in accordance with illustrative embodiments. 
         FIG.  25 A  schematically shows the planets rotate through the sun gear dead zone in accordance with illustrative embodiments. 
         FIG.  25 B  schematically shows the gears when the seat reaches the down position in accordance with illustrative embodiments. 
         FIG.  26 A  schematically shows the planet gears engaged with sun gear during initial booster spring unit return period in accordance with illustrative embodiments. 
         FIG.  26 B  schematically shows the planet gears disengaged from the sun gear at the sun gear dead zone, concurrent with booster unit contacting main spring unit in accordance with illustrative embodiments. 
         FIG.  27 A  schematically shows the booster spring and main spring units lifting the seat to  45  deg position in accordance with illustrative embodiments. 
         FIG.  27 B  schematically shows the main spring unit lifting the seat to the up position. 
         FIG.  28    schematically shows a ratcheting mechanism in accordance with illustrative embodiments. 
         FIG.  29    schematically shows the ratchet input retrofitted to a music box timer mechanism in accordance with illustrative embodiments. 
         FIG.  30    schematically shows a damping system in accordance with illustrative embodiments. 
         FIG.  31 A  schematically shows a toilet seat in accordance with illustrative embodiments of the invention. 
         FIG.  31 B  schematically shows a partially transparent toilet seat with internal channels and chambers for liquid flow in accordance with illustrative embodiments of the invention. 
         FIG.  32    schematically shows a detailed view of the self-lifting toilet seat mechanism in accordance with illustrative embodiments of the invention. 
         FIG.  33 A  schematically shows the relative positions of the starting chamber and the recovery chamber of  FIG.  32    when the seat is in the down position in accordance with illustrative embodiments of the invention. 
         FIG.  33 B  schematically shows the relative positions of the starting chamber and the recovery chamber of  FIG.  32    when the seat is in the up position in accordance with illustrative embodiments of the invention. 
         FIGS.  34 - 36    schematically show a process of activating the delay system of the self-lifting toilet seat in accordance with illustrative embodiments of the invention. 
         FIG.  37    shows a chart of estimated time delay plotted against a cross-sectional area of the flow constriction element in the return flow channel in accordance with illustrative embodiments. 
         FIG.  38    schematically shows a rotary damper system in accordance with illustrative embodiments. 
         FIG.  39    schematically shows the seat in the up position with a recovery chamber that is offset vertically with respect to a starting chamber in accordance with illustrative embodiments. 
         FIG.  40    schematically shows a close-up view of the liquid reset channel that connects the recovery chamber and the starting chamber in accordance with illustrative embodiments. 
         FIG.  41    shows a cross-sectional view of an internal channel geometry in accordance with illustrative embodiments. 
         FIG.  42    shows a transparent frontal view of a toilet seat in accordance with illustrative embodiments. 
         FIGS.  43 A-B  show a cross-sectional view of the front holding chamber in accordance with illustrative embodiments for a toilet seat with and without a gap at the front, respectively. 
         FIG.  44    shows a top cutaway view of a toilet seat with two independent liquid flow loops in accordance with illustrative embodiments. 
         FIG.  45    schematically shows a side view of a toilet seat with a curved profile extending from the starting chamber to the frontal holding chamber in accordance with illustrative embodiments. 
         FIG.  46    schematically shows a cross-sectional view of a toilet seat in accordance with illustrative embodiments of the invention. 
         FIG.  47    schematically shows a top view of a standard toilet seat with a gap at the front in accordance with illustrative embodiments. 
         FIG.  48    schematically shows a top view of a toilet seat in accordance with illustrative embodiments. 
         FIGS.  49 A- 49 B  show initiation of the delay system in accordance with illustrative embodiments. 
         FIG.  50    shows liquid that has accumulated in the front holding chambers passing through the flow constrictions back to the recovery chambers in the rear of the seat in accordance with illustrative embodiments. 
         FIG.  51    shows another cutaway view of the toilet seat in a substantially lifted position where liquid that has accumulated in the recovery chamber flows back to the starting chamber through a reset channel in accordance with illustrative embodiments. 
         FIG.  52 A  shows liquid accumulation in the recovery chamber immediately after the seat reaches the up position in accordance with illustrative embodiments. 
         FIG.  52 B  shows liquid moving back to the starting chamber through the reset channel after reaching the up position in accordance with illustrative embodiments. 
         FIG.  53    shows a rear, cutaway view of reset flow from the recovery chamber entering the starting chamber through an elevated port in accordance with illustrative embodiments. 
         FIG.  54 A-C  schematically shows the seat of the self-lowering embodiment in various positions in accordance with illustrative embodiments. 
         FIG.  55 A  schematically shows a rear view of the hinge of the self-lowering toilet seat system with the seat in the down position in accordance with illustrative embodiments 
         FIG.  55 B  schematically shows a front view of the hinge of the self-lowering toilet seat system with the seat in the up position in accordance with illustrative embodiments. 
         FIG.  56 A  schematically shows a cutaway side view of the toilet seat of  FIG.  55 A  in the down position in accordance with illustrative embodiments. 
         FIG.  56 B  schematically shows a cutaway side view of the toilet seat of  FIG.  55 A  in the neutral state in accordance with illustrative embodiments. 
         FIG.  56 C  schematically shows a cutaway side view of the toilet seat of  FIG.  55 A  in the up state in accordance with illustrative embodiments. 
     
    
    
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     In illustrative embodiments, a toilet seat system is configured to automatically lift a toilet seat to an up position. To that end, the system includes a biasing system configured to lift the toilet seat to the up position. The toilet seat system may also be , referred to as a self-lifting toilet seat system. The self-lifting toilet seat system advantageously reduces the likelihood of waste (e.g., urine) contacting the toilet seat, particularly the surface upon which a user sits. Advantageously, when a user wishes to sit on the toilet seat, they may user-lower the toilet seat, without requiring additional cleaning of the toilet seat. After a user applied force is removed from the seat, the toilet seat system is configured to provide a delay prior to self-lifting the toilet seat back into the up position, so as to reduce the likelihood of the toilet seat accidentally hitting the user when preparing to sit, and to give the user time to leave the toilet seat without the seat impacting the user or their clothing. Additionally, the toilet seat system may be configured such that a user may lift the seat back to the up position at any time without significant difficulty, and without causing harm to the delay system. Accordingly, various embodiments advantageously provide improved cleanliness of the toilet seat and an overall improved user experience. Details of illustrative embodiments are discussed below. 
     In other embodiments, the toilet seat system is configured to self-lower a toilet seat to a down position. To that end, the system includes a biasing system configured to lift the toilet seat to the up position. The toilet seat system may also be referred to as a self-lowering toilet seat system. The self-lowering toilet seat system  100  advantageously reduces the likelihood that a user will forget to lower the toilet seat after use. Details of illustrative embodiments are discussed below. 
       FIG.  1    schematically shows a public restroom  38  in accordance with illustrative embodiments of the invention. The restroom  38  includes one or more stalls  39  each having a toilet  40 . In illustrative embodiments, the toilet  40  includes a self-lifting toilet seat system  100 . The toilet  40  includes a toilet seat  1  upon which a user may sit, and a toilet bowl  44  configured to receive waste from the user. A hinge  46  couples the toilet seat  1  with the toilet bowl  44 . 
       FIG.  2    schematically shows the toilet seat  1  transitioning from the up position  48  to a down position  42  in accordance with illustrative embodiments. Like many standard toilet seats, the seat  1  is configured to transition from the down  42  position to the up  48  position, and vice-versa (e.g., by rotating about the hinge  46 ). The down position  42  is the position on which the toilet seat  1  is meant to be sat upon by a user. The up position is the lifted rested position of the toilet seat  1  (e.g., frequently employed when a male user is urinating). Some embodiments may also have a neutral position where the seats comes to rest after the user&#39;s weight is removed from the toilet seat  1  (e.g., the user no longer sits on the seat  1 ). 
     The hinge  46  allows the seat  1  to rotate from an up position  48  to a down position  50  (e.g., where the seat  1  contacts the bowl  44 ), and to a plurality of positions between the up position  48  and the down position  50 . For example, as discussed further below, some embodiments (e.g., self-lifting) begin the time delay when the seat is user-lowered to a down state and released from the down state (i.e., force holding the seat in the down state is removed), while others (e.g., self-lowering) begin the time delay when the seat is user-lifted to the up state and released from the up state (i.e., force holding the seat in the up state is removed). 
     A self-lifting toilet seat system  100  is advantageous in a public restroom  38  for the reasons described below. The public restroom may have a considerable number of users throughout the day. For example, at sports events, music events, and other public venues, it is likely that hundreds of users may use a particular toilet  40 . Throughout the day, it is likely that the toilet seat  1 , if it remains in the down position  50 , becomes soiled with user waste, and therefore, becomes undesirable sit upon. Large venues frequently require a large number of staff to maintain and clean the toilet seat  1 . Advantageously, self-lifting embodiments allow the toilet seat  1  to remain cleaner than a toilet seat that remains horizontal, as they proactively remove the seat  1  from the proverbial “line of fire,” thereby reducing the burden on cleaning staff and improving the user experience. 
     Although illustrative embodiments refer to toilets  40  in public restrooms  38  and large venues, it should be understood that illustrative embodiments apply to toilets  40  in any setting. For example, illustrative embodiments may be applied to portable toilets, and/or residential restrooms toilet seats  40 . Illustrative embodiments provide a passive, non-electrically powered system, and therefore are particularly suited for high-volume settings without nearby electrical connections (e.g., portable toilets at sporting events/festivals). Battery-powered systems are high-maintenance, require the batteries to be replaced at regular intervals (and to be properly disposed of), and the battery connection and access may compromise long-term reliability. 
     Furthermore, as will be discussed later, various embodiments may advantageously be configured to be self-lowering, wherein the system self-lowers seat  1  to the down position, and therefore, may be particularly suited for residential settings where lowering of the toilet seat  1  is preferred after use.  FIG.  2    schematically shows the toilet seat transitioning from the up position  48  to down position  50  in accordance with illustrative embodiments. 
     In illustrative embodiments of the self-lifting toilet seat system  100 , the down position  50  is a general callout to the location of the seat  1 , regardless of system states. In the down position  50 , the bottom plane of the seat  1  (e.g., the intersection of the surfaces of nubs  5  of seat  1 , if the seat has nubs, or whichever components first contact the bowl  44 ) is substantially parallel to the top plane of the bowl  44  (e.g., about −15 degrees to about 25 degrees). 
     In illustrative embodiments, the up position  48  is a general callout to the io location of the seat  1 , regardless of system states. In the up position  48 , the bottom plane of the seat is substantially perpendicular to the top plane of the bowl  44  (e.g., about 80-115 degrees from the down position). 
     In the down state  50 A a user force is applied sufficient to hold the seat in the down position  50  (e.g., by sitting on the seat  1  or holding the seat  1  down). In is the down state  50 A, the delay system is engaged, and the time delay begins right after or concurrently with the toilet seat  1  entering the neutral state (e.g., after the user removes their applied force from the toilet seat  1 ). In various embodiments, the time delay may be reset or paused by the user forcing the seat back to the down state  50 A. 
     In self-lifting embodiments, the neutral state  49 A is the state of the seat  1  after the seat  1  has been user-lowered to the down state and there is no more user applied force to the seat  1 . In the neutral state  49 A, the user force is removed and the seat remains in the down position  50  until a predetermined time delay expires. The delay system  54  prevents the lifting system  52  from self-lifting the toilet seat  1  towards the up position  48 . Lifting the toilet seat  1  “towards” the up position  48  may include lifting the toilet seat  1  until the seat  1  reaches the up position  48 . The angular position of the seat  1  about the hinge  46  relative to the top plane of the bowl  44  with such a loading case is the neutral position. Although still considered to be roughly in the down position  50 , the neutral position may, in some embodiments, have an angular offset of between about 0 and about 20 degrees from the position of the toilet seat in the down state  50 A. 
     For illustrative embodiments configured to be self-lifting, the seat  1  may be either in the neutral state  49 A or the down state  50 A and still considered to be in the down position  50 . 
     Furthermore, in various embodiments, the seat is “self-lifted” when the lifting system  52  causes the seat  1  to rotate, forcing the seat  1  to the up position (e.g., from the down state through the neutral state to the up position). 
     Furthermore, the user-lowering transitions the seat  1  from the up position to the down position. 
       FIGS.  3 A- 3 C  schematically show the self-lifting toilet seat system  100  in accordance with illustrative embodiments. In particular,  FIG.  3 A  shows a rear view of the toilet seat  1  in the up position.  FIG.  3 B  shows a front perspective view of the toilet seat  1  in the up position.  FIG.  3 C  shows a side view of the toilet seat  1  in the up position. 
     The toilet seat  1  has a contact surface  51  upon which a user sits when the seat  1  is in the down position. On the other side are one or more nubs  5  configured to contact the toilet bowl  44 . The nubs  5  may be formed of a durable material, either as one piece with the toilet seat  1  or as separate parts later as attached. The nubs are sandwiched between the weight of the user on the toilet seat  1  and the toilet bowl  46 . Optionally, the toilet seat  1  may include a handle  2  to assist the user with lifting and/or lowering the seat  1 . The hinge  46  couples the toilet seat  1  with the toilet bowl  44  (not shown in  FIGS.  3 A- 3 C ). 
     In various embodiments, the hinge  46  includes a substantially dust-proof and/or sealed hinge housing  3  and housing base  4 , which couples with the toilet bowl  44 . The connection between the hinge housing  3  and housing base  4  is sealed such that ingress of liquids and dust is prevented during normal usage and maintenance of the seat  1 . Though considered substantially sealed, various embodiments may allow for a small leak of air such that the air pressure in the hinge  46  may equalize to ambient conditions. Additionally, the rotary seal  17  also allows for such a seal between hinge housing  3 , housing base  4 , and the rotating axle  7 . 
       FIG.  4 A and  4 B  schematically show a close-up view of the portion of the toilet seat adjacent to the hinge housing  3  in accordance with illustrative embodiments of the invention. The hinge  46  has a housing base  4  that is configured to couple with the bowl  44 , and an axle  7  that rotatably couples with the seat  1 . To that end, the housing base  4  may be bolted or otherwise fixed to the bowl  44 . Additionally, the axle  7  may include one or more coupling portions (e.g., a bolt hole, D-shaft, etc.) that is configured to align with and couple with a seat coupling portion  6  (e.g., a corresponding bolt hole, a corresponding female D-shaft profile, etc.). The seat  1  is thus rotatably coupled with the hinge  46 , and may rotate relative to bowl  44 . 
     The self-lifting toilet seat system  100  includes a lifting system  52  configured to self-lift the seat  1  towards the up position  48 . The system  100  also includes a delay system  54  configured to delay the lifting system  52  from self-lifting the toilet seat  1  to the up position  48 . Preferably, the delay system  54  and/or the lifting system  52  are positioned within the sealed hinge housing  3  and housing base  4 . For example, this prevents or reduces the amount of contamination, grime, waste (e.g., urine), and/or dust that may accumulate between the suction cup  13  and the attachment surface. This advantageously allows the delay system  54  to operate more reliably and to require reduced maintenance of components relative to an unsealed delay system  54 . 
       FIGS.  5 A- 5 B  schematically show the hinge  46  of  FIG.  4 A  with a transparent housing  3 . In particular,  FIG.  5 A  schematically shows a front perspective view of the toilet seat  1  in the up position  48  (similar to  FIG.  3 B ).  FIG.  5 B  schematically shows a front view of the toilet seat  1  in the up position  48 . 
     In some embodiments, the self-lifting toilet seat system  100  includes a lifting system  52  configured to self-lift the toilet seat  1  towards the up position  48 . In various embodiments, the lifting system  52  may be comprised of a spring  9 , such as a torsion spring  9 , but may also be comprised of a linear compression or extensions spring, and/or a spiral torsion spring. 
     As best seen in  FIG.  6 A , the torsion spring  9  of this configuration may be coupled (e.g., via a first bolt  58 ) to a fixed spring mount  8 . On the other end, the torsion spring  9  couples with an axle link  11  (e.g., via a second bolt  58 , best shown in  FIG.  6 A ). The axle link  11  is fixed to the axle  7 , and therefore, rotates with the axle  7  when the seat  1  is rotated. Thus, when the seat  1  is user-lowered, the torsion spring  9  is loaded (e.g., via the connection of the axle link  11 ), and begins to apply a torque in the direction of self-lifting the seat  1  back to the up position  48 . 
       FIGS.  6 A- 6 C  schematically show a side view of the seat  1  as it is lowered by the user. In  FIG.  6 A , the seat is in the up position  48 . In  FIG.  6 B , the seat  1  is in the neutral state  49 A. In  FIG.  6 C , the seat  1  is in the down state  50 A. Although the position of the seat  1  is shown as being slightly different in the down state  50 A and the neutral state  49 A, it should be understood that some embodiments may have an identical position for the toilet seat  1  in the down position and the neutral position. 
       FIGS.  7 A- 7 B  schematically show a side view of the lifting system  52  in accordance with illustrative embodiments of the invention.  FIG.  7 A  shows the lifting system  52  when the delay system  54  is not engaged (e.g., as the toilet  42  is in the up position  48 ).  FIG.  7 B  shows the lifting system  52  when the delay system  54  is engaged (e.g., when the toilet seat  1  is in the down position  50 ). 
     The side view of  FIG.  7 A  more clearly shows the axle link  11  coupled with the axle  7  as well as with one end of the spring  9 . As the seat  1  is user-lowered towards the down position  50  (shown in  FIG.  7 B ), the spring  9  is loaded and applies a counter torque back towards the direction of the unloaded, up position  48 . Because the spring  9  is coupled with the axle link  11 , the torque of spring  9  is applied to the axle link  11 , which relays that torque to the axle  7 , and thus to seat  1 . Lowering the toilet seat towards the down position  50  may include lowering the toilet seat until the seat  1  reaches the down position  50 . 
       FIGS.  11 A- 11 D  schematically show an alternative embodiment of the lifting system  52  in accordance with illustrative embodiments. In various embodiments, the lifting system  52  may include a torsional spring  9  (shown in  FIGS.  5 A- 5 C ), but in alternative embodiments, a linear spring  9  on a lever arm (as shown in  FIG.  11 A ).  FIG.  10    schematically shows the associated torque profiles for a linear spring in accordance with illustrative embodiments. For the linear spring  9  embodiment, a relatively close match of seat  1  to spring  9  torque may be created, which reduces the net torques experienced by all downstream components when the seat  1  is actuated. Additionally, spiral torsion springs, compression springs, and other types may be used as well. 
       FIG.  6 B and  6 C  schematically show a side view of the toilet seat  1  the down position  50  in accordance with illustrative embodiments. As mentioned previously, it is desirable to provide a delay in the self-lifting of the toilet seat  1 . Accordingly, illustrative embodiments provide a delay system  54  configured to delay and/or slow the self-lifting of the toilet seat  1  effectuated by the lifting system  52 . Preferably, the delay system  54  provides a sufficient delay to allow the user to get ready to use the toilet  40 , as well as finish using the toilet  40  and to prepare themselves to exit the stall  39 . In illustrative embodiments, the delay system  54  delays and/or slows the self-lifting of the toilet seat  1  to the up position  48 , for between about 1 second and about 5 minutes. 
     When the toilet seat  1  is user-lowered to the down state  50 A (e.g., by a user who wishes to sit on the seat  1 ), the motion of the seat  1  causes a corresponding motion that engages the delay system  54  (e.g., within the housing  3  and housing base  4 ). For example, as shown in  FIG.  6 B and  6 C , the delay system  54  is configured such that the suction cup  13  couples to the attachment surface  56  when the toilet seat  1  approaches or reaches the down position  50 . 
     In illustrative embodiments, when the seat approaches the down position  50 , the cups  13  come in contact with the attachment surface  56 . As the seat  1  comes to the down state  50 A, the suction cups  13  compress onto the surface  56  and expel the majority of the fluid (for example, air or oil) between the cups  13  and the surface  56 . This creates a pressure imbalance such that when the seat  1  experiences a torque from the lifting system  52  towards the up position  48 , the cups  13  are able to use that pressure imbalance to “stick” to the surface and delay the self-lifting of the seat  1 . 
     The delay of the self-lifting of the seat  1  by the delay system  54  is created by integrating a controlled leakage channel  18  (discussed in further detail below) into cup  13  or plate  14  to allow for a slow leak of fluid back into the cup  13 . Due to the force separating the cup  13  and plate  14  that is translated from the lifting system  52  to the delay system  54  through the linkage components  10 , 11 , and  12 , (as well as the elastomeric memory of the suction cup) fluid is forced to leak into the cup  13 . Once enough fluid has entered so as to substantially equalize the internal and external cup  13  pressures, the cup  13  and the plate  14  are easily separable. Carefully controlling this flow back into the cup  13  allows for an adjustable delay system  54  to be created such that when enough fluid has re-entered the cup  13  to equalize the pressure, the cup  13  no longer has any holding power and the springs  9  simply self-lift the seat  1  back into the up position  48 . When this happens, the cups  13  are driven back to their starting position through the linkage. Thus, the cups  13  coupled with plate  14  act as a delay system  54 , and the toilet seat  1  does not immediately self-lift after a user removes their lowering force, giving the user time to sit down or rise up before the delay expires. 
     Advantageously, the pressure differential-based force that holds the cup  13  down to plate  14  allows for a user to self-lift the seat  1  to the up position  48  at any time during the duration of the delay system  54 . If the force that is translated to the delay system  54  by the user&#39;s exerted force on the seat  1  is larger than the holding force of cup  13  onto plate  14 , then the delay system  54  will disengage and allow the user to self-lift the seat to the up position. Thus, the user is able to overcome the holding force of the cup  13  on the plate  14  with relative ease because of the significantly longer lever arm that the user has at the tip of the seat  1 , compared to the relatively short lever arm of the cup  13  inside the hinge  46 . Additionally, the elasticity of the cup  13  means that the cup  13  is able to easily disengage from plate  14  under the relatively low lifting force from the user, thereby not causing any injury to the user, or damage to the seat and internal linkage components (discussed below). 
     The suction cup  13  may be mounted relative to the axle  7  such that rotary motion from the toilet seat  1  is relayed through the axle  7  to the suction cup  13 . Although the suction cup  13  is shown as engaging the plate  14  when the toilet seat  1  is near the down position  50 , it should be understood that the position and/or dimensions of the plate  14 , as well as the internal linkages (e.g.,  10 ,  11 ,  12 ), position, and size of the suction cup  13  may be tuned to engage at any point along the transition of the seat  1  from the up position  48  to the down position  50 . 
     In the current embodiment, the axle link  11  may be coupled to an interlink  12  (e.g., through rotary link  15 ) that is fixed to the delay system  54  (e.g., suction cup  13  and plate  14 ), as discussed further below. Thus, movement of the toilet seat  1  may be relayed through the axle  7  and various links (e.g.,  10 ,  11 ,  12 , etc.) to the delay system  54 . In some embodiments, a second link  10  is coupled to the interlink  12  (e.g., through rotary link  16 ) to maintain a desirable orientation of the delay system  54 . 
     Furthermore, some embodiments may include a linkage (e.g.,  10 ,  11 ,  12 ) to transfer the rotational motion of the seat  1  to the suction cup  13 , as a suction cup may function most effectively when it is travels linearly and is applied normally to a contact surface, such as the surface  56  of timing plate  14 . The linkage may be comprised of a driving link  11  (also referred to as the axle link) and a secondary link  10  rotatably affixed to pivot point  21 . These two links may be rotatably affixed to another intermediate link  12  via rotatable connection points  15  and  16 , thus forming a four-bar linkage. Such a configuration is advantageous as the suction cup  13  may be fixed to the intermediate link  12  so as to achieve a substantially linear motion of the suction cup  13  as the seat  1  moves into the down position  50  and contacts the timing plate  14 , but rotation of the cup  13  when the seat  1  is in any other position. This allows for a compact design of case  3  and a robust, low-friction coupling between the suction cup  13  and plate  14 . 
     In alternative embodiments, the seat  1  remains fixed to the rotating axle  7  shaft at the housing base of the seat  1 . As seen in  FIG.  11 A , the axle  7  translates the rotary motion of the seat  1  to axle link  11  that is rotatably fixed to the axle  7 . As seen in  FIGS.  11 B and  11 C , the axle link  11  in turn drives the link  32 , which in turn drives link  33 , onto which the delay system  54  is mounted. Link  33  is constrained to travel linearly, and thus, in some embodiments, the linkage shown in  FIGS.  11 A- 11 C  convert the rotational motion of the seat  1  into linear motion (e.g., similar to linear piston actuation). This method is advantageously suitable for delay system  54  integration with viscous fluid. 
       FIGS.  11 B- 11 C  schematically show a perspective view of the device of  FIG.  11 A .  FIG.  11 D  schematically shows a rear perspective view of the device of  FIG.  11 A . In  FIG.  11 B , the delay system  54  is disengaged. In  FIG.  11 C , the delay system  54  is engaged. When the seat  1  is lowered, the axle link  11 , via pinned links  32  and  33 , moves the cups  13  through a fluid medium relatively unimpeded, until the seat  1  approaches the down position  50 . 
     Other linkages, such as a plane change linkage  30  as shown in  FIGS.  12 A and  12 B , a six-bar linkage  31  as shown in  FIG.  13   , and others such as a barrel cam linkage, rack and pinion style linkage, etc. are other embodiments of this motion translation system which allow for linear, or substantially linear motion of the suction cup as the cup  13  approaches and contacts the plate  14 . In some other embodiments, there is a direct linkage between the seat  1  and delay system  54 , wherein the suction cup  13  is affixed directly to the axle link  11 . Accordingly, the delay system  54  may have a non-normal pull off force due to the rotation of the seat  1 , and therefore cup  13 . Though this may advantageously simplify the linkage, a taller housing is undesirably required to accommodate the end effector  13  of the delay system  54  rotating a full 90 degrees or more with the seat. Undesirably, the non-normal force may also distort the shape of the suction cup, causing an unpredictable/inconsistent timing delay. 
     In various embodiments, the delay system  54  may include one or more suction cups  13  configured to couple with a timing plate  14  having a contact surface  56 . In various embodiments, the shape, hardness, and/ or positioning of the suction cup  13  is configured in conjunction with the size and placement of the fluid leakage channels  18  to provide the desired time delay. Specifically, when the suction cup  13  disengages from the contact surface  56 , the seat  1  begins to self-lift due to the torque from the lifting system  52 . Preferably, both the contact surface  56  and the suction cup  13  are kept clean of surface contaminants to allow for consistency in the time delay. For example, getting waste and/or dust on either the contact surface  56  or the suction cup  13  cause an unreliable and/or premature time delay. Thus, various embodiments seal the contact surface  56  and/or the suction cup  13  within a dust-proof housing  3  via rotary seals  17 . 
     However, as discussed further below, the suction cup  13  and/or the timing plate  14  may include one or more controlled leakage channels  18 . In some embodiments, the controlled leakage channel  18  may be integrated into the suction cup  13  by using a material with a known and appropriate bulk porosity. In the same manner, the timing plate  14  can itself function as the controlled leakage channel  18  when the material used for the plate  14  has an appropriate bulk porosity. The controlled leakage channels  18  may also be covered by an additional filter or other flow reduction device, should the controlled leakage channels themselves be insufficient in achieving the desired time delay. In other embodiments, as shown in  FIG.  9 B , a carefully configured groove  57  may be installed onto the plate  14 , such that when the suction cup  13  is in contact with the plate  14 , the groove  57  spans the distance between the inside and outside of the cup, allowing a controlled amount of fluid to flow into the cup and function as the controlled leakage channel  18 . Such a configuration is advantageously simple from a mass manufacturing perspective as the plate  14  may be integrated directly into the housing base  4 . In further embodiments, the plate  14  or cup  13  may be coated with an adhesive substance, such that when the suction cup  13  contacts the plate  14 , it adheres to it using temporary adhesive forces. In such an embodiment, the cup  13  may consist of a rigid material. 
       FIG.  9 A  schematically shows the timing plate  14  in accordance with illustrative embodiments. In some embodiments, the timing plate  14  has a smooth surface  56  to ensure a strong seal between the cup  13  and the surface  56 . Various embodiments may form the plate  14  or the surface  56  from, for example, a smooth, glossy plastic. Some other embodiments may form the plate  14  or the surface  56  from an acrylic, HDPE, Teflon, glass and/or or polished metal. 
     As mentioned previously, the timing plate  14  may include one or more controlled leakage channels  18 . The controlled leakage channels  18  may be one or more small holes/vias in the plate  14  that are configured to allow a slow and controlled flow of fluid (e.g., air, viscous oil) between the cup  13  and the plate  14  when cup  13  is engaged with plate  14 . Placing these controlled leakage channels  18  in the plate  14  such that they align with the center of the cup  13  allows for fluid to be constantly drawn back into the cup  13  as the linkage pulls on the cup  13  via the lifting springs  9 . Preferably, various embodiments use several holes of diameter 0.1 mm-0.5 mm to achieve a preferred timing range of 5-45s, however some embodiments may have larger holes (e.g., &gt;0.5 mm diameter) which advantageously reduce the likelihood that the controlled leakage channels  18  are clogged by dust particles or other contaminants. Additionally, or alternatively, the controlled leakage channel  18  may include a groove  57 , porous material, and/or textured material. 
     To assist with preventing dust particles from passing through the controlled leakage channels  18 , as well as assist in reducing the fluid flow through the controlled leakage channels, some embodiments may include a filter over the controlled leakage channels  18 . Examples of filter materials include Tyvek, sintered Teflon powder such as Porex, densely woven fabrics and vapor permeable air barrier tapes. The diameter of the channels  18  as well as the filter permeability strongly influence timing. While a hole/filter arrangement is advantageous for the delay system, other methods to induce a controlled flow through the controlled leakage channels for controlling the delay system  54  include a needle valve, textured surface, porous surface  56 , porous suction cup  13 , etc. 
       FIGS.  9 B- 9 C  schematically show another embodiment of the plate  14  in accordance with illustrative embodiments. The plate  14  may include quick release channels  18 B at a designated distance from the controlled leakage channels  18 A. Since the suction cups  13  stick to the plate  14  due to a pressure imbalance as well as adhesive stiction, it can be difficult to control the exact point of release of the cups  13 . When the seat  1  is in the neutral state and the delay system  54  is soon to expire, the cup  13  may be tenaciously holding on to plate  14  by only its outermost rim. At this point, the release point uncertainty may be high. To avoid dealing with this uncertainty, quick release channels  18 B may be added to the plate  14  at a particular radial distance away from controlled leakage channels  18 A. When the cup  13  is first compressed, these holes  18 B are covered by the cup  13  material and are therefore not able to transmit any fluid into the cup  13 . However, when the cup  13  deflects to a certain level after enough fluid has flown in through the controlled leakage channels  18 A, the quick release channels  18 B (optionally covered by a filter) are exposed to the fluid pooling in the center of the cup  13 . The quick release channels  18 B allow for a large flow rate and substantially instantly allow enough flow so as to equalize pressure and quickly release the cup  13 . 
     In various embodiments, characteristics of the cup  13  can negate the issues presented by the uncertain release point seen in non-ideal cups  13 . Various embodiments may use flat cups  13  with low nominal deflection. It should also be noted that the cups  13  and the linkage(s) move through room temperature air in various embodiments. However, some embodiments provide a new ambient fluid, such as viscous oil. Accordingly, the controlled leakage channel  18  size needed to achieve the same flow rate as with air becomes much larger, while the suction cup  13  elastomer is protected from oxidation. This also advantageously addresses issues like dust clogging the system. Additionally, if the cups  13  are mounted on the end of a piston actuating through a cylinder filled with oil, a circular plate  14  can be affixed to the piston, with an outer diameter similar to that of the inner diameter of the cylinder. Doing so creates a damping effect that eliminates any potential slamming of the seat  1  on the way to the up position  48  (e.g., by the lifting system  52 ) and further may eliminate the need for an additional damper component (e.g., damper  19 ). 
     It should be appreciated that various embodiments may provide a passive opening system  52  and/or delay system  54 . The biasing system  52  and/or delay system  54  may operate without the use of electrically powered components. Thus, the opening system  52  and/or delay system  54  advantageously operate without the need for an electrical power connection or changing of batteries. The opening system  52  and/or delay system  54  therefore reduce the need for maintenance, and additionally, allows for use in toilets  40  that are not near to an electrical connection (e.g., portable toilets). Furthermore, illustrative embodiments provide a single action for initiating the lifting system  52  and the delay system  54  (e.g., lowering the toilet seat  1 ). 
       FIG.  14    shows a process of self-lifting the toilet seat  1  in accordance with illustrative embodiments of the invention. The process begins at step  1402 , which provides the toilet seat system  100  as described herein. In various embodiments, the toilet seat system  100  includes the toilet seat  1 , the toilet bowl  44 , and the hinge  46 . In some embodiments, the toilet bowl  44  may already be installed at a desired location. Therefore, the system may include the toilet seat  1  and the hinge  46 , which may be retrofitted to couple with the toilet bowl  44 . In various embodiments, the hinge  46  (e.g., the housing  3  and housing base  4 ) may be configured to bolt or otherwise couple with the toilet bowl  44 . As discussed below, the hinge  46  also couples to the seat  1  and preferably allows the seat  1  to move and/or rotate relative to the bowl  44 . 
     In various embodiments, the hinge  46  preferably includes a housing  3  and housing base  4 . Preferably, the housing  3  and housing base  4  are sealed and waterproof. Preferably, the rotation of the axle  7  is also sealed via rotary seal  17 . Inside of the housing  3  and housing base  4  is the delay system  54 . Additionally, the housing  3  and housing base  4  may contain the lifting system  52  and the io linkages (e.g.,  10 - 12 ,  30 - 33 ). In some embodiments, as shown in  FIG.  8   , the cup  13  and the plate  14  is further isolated within this housing  3  using a bellows  55  or other seal that encloses the plate  14  and cup  13  in a fully dustproof manner while continuing to allow the full range of motion of the suction cup  13 . 
     At step  1404 , the user lowers the toilet seat  1 . When the toilet seat  1  is user-lowered, the lifting system  52  begins to provide a counter torque to the seat  1  towards the up position  48 . At some point during the lowering of the seat  1 , preferably when the seat approaches the down state  50 A, a delay system  54  engages, causing the toilet seat  1  to remain in the in the down state  50 A until the user removes their applied force from the seat  1 . 
     The process then proceeds to step  1406 , which begins the time delay once the user&#39;s applied lowering force is removed. When the user applied lowering force is removed, the seat will transition to the neutral state  49 A due to the torque applied to the system by the lifting system  52 , which is configured to overcome the torque of the seat  1  when the time delay of delay system  54  expires. As described previously, the delay system  54  may include a suction cup  13  and a plate  14 . In some other embodiments, the delay system  54  may include some other type of adhesive. Furthermore, some embodiments may include a gear based delay system  54  or a fluid-channel based delay system  54  , as described in alternative embodiments further below. 
     At step  1408 , the process asks whether a user sits or applies lowering force before the time delay expires? If so, in some embodiments, the time delay is reset. However, in some other embodiments, the time delay is paused as the user sits. Thus, if a user sits on, or otherwise applies a threshold-lowering force to the toilet seat  1  prior to the expiration of the delay system, the toilet seat  1  will not self-lift via the lifting system  52  to the up position  48 . Instead, the process moves to step  1410  where the delay system  54  will experience a reset or pause to its delay. 
     When the user sits on the seat  1 , their weight is applied to the toilet seat  1 . Although the delay system  54  may be engaged by the user sitting on the toilet seat  1 , the weight of the user is preferably not directly on the delay system  54 . For example, some embodiments may position suction cups  13  underneath the toilet seat  1  such that the suction cups  13  engage a surface of the toilet bowl  44 . However, this is not preferred for a number of reasons. First, the weight of the user is likely to damage the suction cups  13  over time. Also, the toilet bowl  44  surface is not sealed, and is likely to become contaminated over time, reducing the quality and reliability of the time delay over time. Thus, illustrative embodiments have linkages between the toilet seat  1  and the delay system  54  to indirectly use the weight of the user on the toilet seat  1  to engage the delay system  54 . 
     Furthermore, after the user has finished using the toilet  40 , the user stands up from the toilet seat  1  at step  1412 . By standing up, the user removes the threshold weight from the seat  1 . In some embodiments, removing the weight from the seat  1  causes the seat to transition to a neutral position  49 A.  FIGS.  16 A- 16 C  schematically show the seat  1  in different positions.  FIG.  16 A  schematically shows the seat  1  in the up position  48 .  FIG.  16 B  schematically shows the seat  1  in the down state  50 A, and  FIG.  16 C  schematically shows the seat  1  in the neutral state  49 A. To that end, some embodiments may include a component that pushes the seat  1  back to the neutral position  49 A as soon as the user rises (i.e., before the time delay expires). Additionally, or alternatively, the delay system  54  may have some slack that causes the seat  1  to move to the neutral position  49 A as the user rises. 
     After the user stands up from the seat  1  in step  1412 , the system loops back to step  1406  and the delay system  54  resumes or restarts, after which the process once again asks whether a user lifts the seat. If not, the system once again asks if the user sits before the time delay expires. If they do, the cycle continues as described above, however, if a user does not sit or otherwise apply a threshold lowering force to the toilet seat  1  prior to the expiration of the delay system  54 , the process moves to step  1414   14 , and the toilet seat  1  self-lifts to the up position, and the process is complete at step  1416  with the seat in the up position. 
     Additionally, the user may lift the seat  1  to the up position at any point in the cycle, for example at intermediate steps  1405  or  1409 . However, some other embodiments may not allow the user to lift the seat  1 . 
       FIG.  14    describes a method of lifting a toilet seat  1  in accordance with illustrative embodiments of the invention. It should be noted that this method is substantially simplified from a longer process that may normally be used. Accordingly, the method shown in  FIG.  14    may have many other steps that those skilled in the art likely would use. In addition, some of the steps may be performed in a different order than that shown, or at the same time. Furthermore, some of these steps may be optional in some embodiments. Accordingly, the process  1400  is merely exemplary of one process in accordance with illustrative embodiments of the invention. Those skilled in the art therefore can modify the process as appropriate. 
     In an alternative embodiment of the self-lifting toilet seat system  100 , a different configuration is presented. Here, the spring  9  of the lifting system  52  is a linear spring  9 , where the torque of the linear spring is always slightly greater than that of the seat, except in the region where the seat is near the down position  50 . In the near down position  50 , the spring  9  torque of the lifting system  52  that works to self-lift the seat, falls below the torque of the seat, meaning that the seat will “latch” or “hold” itself down due to the torque imbalance, and stays down indefinitely if no other system acts on it.  FIG.  17    schematically shows the torque profiles of the seat  1  vs the lifting system  52  in accordance with such an illustrative embodiment. In contrast to  FIG.  10   ,  FIG.  17    shows that the torque profiles of the main spring  9  and the seat  1  are such that the main spring  9  is unable to lift the seat when the seat  1  is in the down position  50 . Thus, illustrative embodiments rely on the booster spring unit  62  to help lift the seat  1 , for example, as shown in  FIG.  19   . 
       FIG.  18    schematically shows an alternative embodiment of the lifting system  52  in accordance with illustrative embodiments. Various embodiments may include a main spring unit  66 , which includes a spring directly rotatably coupled to the seat  1 , such that for any new position of the seat  1  there is a new deflection of the spring of main spring unit  66 . Thus, there is no lost motion in the spring of main spring unit  66 . In the present embodiment, the spring  66  is a linear spring on a lever arm, but it may also be a torsion spring or any other type of spring. 
     Various embodiments may include a booster spring unit  62 , which is a spring  62  rotatably coupled to the seat  1 , such that it is only engaged during the travel of the seat  1  where it is near the down position  50 . In the present embodiment, the booster spring  62  is engaged by a dog-type coupling (e.g.,  63 ,  67 ) between the mainspring  66  and booster spring  62  units at a seat angle of 45 degrees from the down position  50  Due to the dog coupling between the main spring unit  66  and booster spring unit  62 , as well as the “self” latching of the seat  1 , the user is able to self-lift the seat  1  to the up position  48  regardless of the state of any of the internal hinge  46  components. Additionally, no further clutching or disengagement system is needed to achieve such functionality. However, the spring  62  type, coupling type, and location of coupling may vary for other embodiments of the system. 
     Various embodiments may include a neutral spring unit  64 , which is a spring  64  rotatably coupled to the seat  1 , such that it is only engaged when the seat  1  travels between the neutral state  49 A and the down state  50 A. In the various embodiments, the neutral position  49 A may be about 3 degrees above the down state  50 A. Both values can vary by however, based on the desired is implementation. Additionally, it is possible for backlash in the system to raise the seat from the down state to the neutral state without the need for a neutral spring unit  64 . 
     In various embodiments, the seat  1  is user-lowered from the up position  48  until main spring unit  64  engages with booster spring unit  62 . The seat  1  is user-lowered from the point of engagement of main spring  64  and booster spring  62  units down until the neutral state  49 A (e.g., 3 degrees above the top plane of bowl  44 ). The seat  1  is then user-lowered to the down state  50 A, fully engaging both main  66 , booster  62 , and neutral spring  64  units. The neutral spring unit  64  then rotates the seat  1  and main spring  64  unit from the down state  50 A to the neutral state  49 A. The main spring  64  is unable to self-lift the seat from the neutral state  49 A due to the designed torque imbalance, therefore the seat  1  remains in the neutral state  49 A. Since the booster spring unit  62  is independent of the main spring unit  64 , it remains in the position it is placed into by the seat  1  when the seat  1  is user-lowered to the down state  50 A. However, when the seat  1  transitions from the down state  50 A to the neutral state  49 A, the booster spring unit  62  is no longer loaded by seat  1  via contact from the main spring unit  66  and is free to begin to return to its original position. The booster spring unit  62  rotation to re-engage with the main spring unit  66  dog  63  (still in neutral position  49 A) is slowed by a heavy gear train. 
     In some embodiments, after a time delay (e.g., about 30 seconds), the booster spring unit  62  makes contact with the main spring unit  62 . The gear train io (e.g.,  68 - 80 ) slowing the booster spring unit  62  down releases near this moment of contact, allowing for the booster spring unit  62  to quickly return to its uncompressed state. In doing so, the booster spring unit  62  self-lifts the seat to the location where the booster spring unit  62  is first engaged by the main spring unit  66  (e.g., 45 degrees). The seat is then self-lifted from the intermediate booster engagement location to the up position by the main spring unit  66  of the lifting system  52 . 
     When seat  1  is in the down state  50 A, the booster spring  62  is fully engaged, and the neutral spring  64  self-lifts the seat  1  into the neutral position  49 A. This allows the seat  1  to sit at a slightly elevated neutral position  49 A, while the booster spring unit  62  winds down the timer of the delay system  54  and approaches the main spring unit  66 . The advantage of such an arrangement is that the seat  1  remains perfectly motionless in the neutral state  49 A while the booster spring unit  62  rotates. Without the neutral spring unit  64 , the seat  1  would slowly creep upwards, coupled with the booster spring unit  62  as the delay system  54  runs down. However, given enough backlash in the gearing systems, the seat  1  may simply lift to the neutral state  49 A, or even farther on its own. In that case, the neutral spring system  64  can be removed. 
     To overcome the torque imbalance when the seat  1  is near the down state  50 , the booster spring  62  is engaged to assist in self-lifting the seat  1  to a point where the main counterbalance spring  66  can self-lift the seat on its own.  FIG.  19    schematically shows the torque sharing scheme in accordance with illustrative embodiments. Returning to  FIG.  18   , the booster spring unit  62  may be a linear spring attached to a lever arm, affixed to the main rotating axle of the seat, and coupled to the main counterbalance spring via a dog connection  65 . In other embodiments, a torsion spring, or other clutching mechanism may be employed. 
     The booster spring  62  engages at some point during the lowering of the seat  1 , before the seat  1  torque eclipses the main spring unit  66  torque. After the seat is fully user-lowered to the down state  50 A, both the booster  62  and main spring units  66  are fully engaged, and self-lifts the seat back into the up position, assuming no other forces are applied to the system. However, two things happen from here that allow the seat  1  to remain lowered for an extended period of time:
         1. The neutral spring unit  64  self-lifts the seat  1  a few degrees, such that the dog connection  63  and  67  between the main spring unit  66  and the booster spring units  62 are no longer in contact.   2. The booster spring unit  62  is rotatably coupled to a timing mechanism. The coupling runs through a ratcheting mechanism (eg,  75 ,  76 ) to a heavy gear reduction  78 , which is arranged such that as the booster spring unit  62  tries to return to the unstretched state, the booster spring unit  62  winds the entire gear train back with it, which causes a delay in the booster spring unit  62  dog connection  67  coming back into contact with the main spring unit  66  dog connection  63 . The time it takes for the booster spring unit  62  to catch up to the main spring unit  66  (which is in the neutral state  49 A) is what creates the delay of the seat in the down position  50 . The gear train then disengages due to a special gear train disengagement mechanism ( 71 - 74 ), and allows the booster spring unit  62  to rapidly return to its unstretched state, which self-lifts the seat  1  to a point where the mainspring unit  66  can self-lift it all the way back to the up position  48 .       

       FIG.  20    schematically shows a partially exposed view of the delay system  54  gearing rotatably coupled to the lifting system  52  of  FIG.  18   . The delay system  54  allows the booster spring  62  to slowly return from its position when the seat is in the down state  50 A, to its position when the seat  1  is in the neutral state  49 A, to create the desired seat delay period. The delay system  54  engages for the return portion of the cycle, and disengages after the booster spring unit  62  dog connection  67  is nearly engaged with or has just begun to engage with the main spring unit  66  dog connection  63 . To accomplish this functionality, the delay system consists of several stages of gearing: 
       FIG.  21    schematically shows a first planetary gearing set in accordance with illustrative embodiments. The first planetary gearing increase (e.g., as in this first set of gears increases the gear ratio between the input and output of the gear set),takes the planetary gears  68  as input, which are rotatably fixed to the booster spring unit  62 , and outputs rotation of sun gear  70 . The sun gear  70  output rotates (e.g., 3.75 times) more than the input, but the gear ratio can be modified for other timing schemes by modifying the relative diameters of the ring gear  72 , planet gears  68 , or sun gear  70 . 
       FIG.  22    schematically shows a second planetary gearing increase in accordance with illustrative embodiments. The sun gear  70  of the first planetary set outputs to the planetary carrier input  70  of the second planetary gearset. The ring  72  remains fixed and the output of the second planetary gearset is the sun gear  69 , as in the first set. In the current embodiment, the output speed is (e.g., 3.75×) the input speed, but this may again be adjusted as needed. 
       FIG.  23    schematically shows a planetary gearing increase and targeted disengagement gear  71  in accordance with illustrative embodiments. The sun gear  69  output of the second planetary gear set serves as the ring gear input  69  to the third planetary gearset. In this third planetary gearset, there are two, fixed, planetary gears  68 . The sun gear  71  is a sector gear with several missing teeth. These missing teeth serve as part of the targeted disengagement mechanism, which allows the booster spring unit  62  return profile to be slow for a very small distance, followed by a longer and much faster motion. This functionality is achieved with the addition of a biasing boss  71 A affixed to the sun gear  71  (shown best in  FIGS.  24 A- 27 B ), along with a bi-directional biasing spring  73 . 
       FIG.  24 A  schematically shows the gears of the third gearset when the seat is in the up position  48  in accordance with illustrative embodiments.  FIG.  24 B  schematically shows the main spring unit  66  engaged with booster spring unit  62  in accordance with illustrative embodiments. The initial orientation with the seat  1  in the up position  48  is shown in  FIG.  24 A . In this orientation, the booster  62 and main spring units  66  are in the same position. As the seat  1  is user-lowered, the main spring unit  66  rotates with it in the counter-clockwise direction about the central axis of the axle  7 . After the seat  1  user-lowers far enough such that the main spring unit  66  engages with the booster spring unit  62 , as shown in  FIG.  24 B , the booster spring unit  62  will also begin to rotate in the counter-clockwise direction with the seat  1 . This will cause the ring gear  69 , and therefore the planets  68  of this section, to rotate in the counter-clockwise direction as well. After this occurs, the sun gear  71 is rotated in the clockwise direction, which causes the biasing boss  71 A on the sun gear  71  to engage with the biasing spring 73 , causing a clockwise torque to be applied to the sun gear  71 , just as the planets  68  fall into the dead zone of the sun gear  71 . 
       FIG.  25 A  schematically shows the planets  68  rotate through the sun gear  71  dead zone in accordance with illustrative embodiments. As the seat continues to lower, the counter-clockwise torque on the sun gear  71 , and the planet gears&#39;  68  positions in the dead zone means that for any further lowering of the seat  1 , the sun gear  71  remains nearly stationary. Each next tooth on the planet gears  68  simply hits the sun gear  71  and keeps rotating, without ever actually meshing. This position is shown in  FIG.  25 A .  FIG.  25 B  schematically shows the planet gears  68  when the seat  1  reaches the down position in accordance with illustrative embodiments. As the seat enters the down state, the sun gear  71  remains in the same position. 
       FIG.  26 A  schematically shows the planet gears  68  engaged with sun gear  71  during initial booster spring unit  62  return period in accordance with illustrative embodiments.  FIG.  26 B  schematically shows the planet gears disengaged from the sun gear  71  at the dead zone, concurrent with booster spring unit  62  contacting main spring unit  66  in accordance with illustrative embodiments. 
     After the seat  1  is user-lowered, pressure from the user is removed (e.g., as the user prepares to sit on the seat  1 ). Thus, the return force of the booster spring unit  62  forces the booster spring unit  62  in the clockwise direction. In  FIGS.  26 A and  26 B , it is assumed that the neutral spring unit  64  has already self-lifted the seat  1  into the neutral position  49 A, and the seat  1  is stationary as the booster spring unit  62  rotates slowly in the clockwise direction. The clockwise rotation of the booster spring unit  62  forces the ring gear  69  and the planets  68  of this section to rotate in the clockwise direction as well. Since the sun gear  71  is biased into the counter-clockwise direction, and the planets are now rotating in the clockwise direction, they are able to re-mesh with each other. Thus, the sun gear  71  is driven in the counter-clockwise direction by the planets  68  until the next sun gear  71  dead zone is reached. This travel distance translates to the traversal of the booster spring unit  62  from the down state  50 A to the neutral state  49 A, and means that the main spring unit  66  and the booster spring  62  unit are now back in contact via the dog linkage  63  and  67 . As shown in  FIG.  26 B , after the last tooth of the sun gear  71  has nearly disengaged, the biasing block  74  will have come into contact with the other end of the biasing spring  73 , thereby biasing the sun gear  71  into the clockwise direction. Since the planets  68  are turning in the clockwise direction, the teeth of the planets  68  simply skip over the clockwise biased sun gear  71 . Thus, the gear train downstream of the sun gear  71  is no longer engaged, and there is little force resisting the booster spring unit  62  torque. 
       FIG.  27 A  schematically shows the booster spring unit  62  self-lifting the seat  1  to the  45  deg position in accordance with illustrative embodiments.  FIG.  27 B  schematically shows the main spring unit  66  self-lifting the seat  1  to the up position  48 . Because the rest of the downstream gear train is disengaged and is not resisting the self-lifting torque of the booster spring unit  62 , the booster spring unit  62  quickly restores to its original position, self-lifting the main spring unit  66  (and therefore the seat  1 ) into the 45 degree position as shown in  FIG.  27 A . From here, the main spring unit  66  has enough torque to self-lift the seat  1  into the fully up position, and the cycle is ready to run again. From  FIG.  27 A- 27 B , the pictured gear train components have not moved, as the booster spring unit  62  remains stationary for the last 45 degrees of seat  1  self-lifting. 
     Downstream of the disengagement mechanism,  FIG.  28    schematically shows a ratcheting mechanism ( 75 ,  76 ) in accordance with illustrative embodiments. Various embodiments include a one-way ratchet. There is a further gearing increase after the three planetary gear trains, as the three planetary geartrains alone do not contribute to a significantly large enough gearing increase to achieve the desired timing. However, in order to avoid having to use excessive force to lower the seat, the afore-mentioned ratchet ( 75 ,  76 ) is placed between the three planetary gear trains and the further gearing downstream. This way, upon user-lowering the seat  1 , the ratchet clicks through and avoids engaging anything further on, but in the self-lifting direction, the ratchet engages and forces the entire downstream gear train to rotate, thus providing the long delay for the booster spring unit  62  return. 
       FIG.  29    schematically shows the ratchet output  76  retrofitted to a music box timer mechanism  78  in accordance with illustrative embodiments. The ratchet output  76  is fed through gear  77  directly into a music box timer  78 . This creates the desired significant speed increase to the final gear train component—the music box air damper  79 . A friction damper may also be used, but it may experience wear from excessive use, and may create some undesirable noise. The music box gear train  78  is advantageous due to its compact design that produces a significant gearing increase. However, a custom gearing solution, along with any other damping or restraining mechanism can be used as well. 
       FIG.  30    schematically shows a damping system  80  in accordance with illustrative embodiments. The damping system  80  is preferred in order to slow the self-lifting of the seat  1  as the booster spring unit  62  and main spring unit  66  self-lift the seat  1  to the up position  48 . In the present embodiment, this damper  80  consists of parallel plates, consecutively stacked such that one plate is fixed to the damper housing and the next plate is fixed to the rotating axle  7 . The space between each plate is filled with grease, and thus a rotary shear damper is created. Any other damping method is acceptable, such as linear damper  19 , and it is preferable that the damping occurs only during the rotation that causes the seat  1  to self-lift, so that the user does not have to fight the damper system  80  to user-lower the seat  1 . 
     It should be understood that the above-described gear mechanism describes one specific mechanism that works to achieve the claimed functionality. There are alternative embodiments that may work as well. For example, in the present embodiment, the seat  1  latches itself due to a torque imbalance between the main spring unit  66  and the seat  1 . Alternatively, the main spring unit  66  could be a bistable spring, which rather than simply slowly reducing its torque, changes the directionality of its torque at a point during the lowering of the seat  1 . Alternatively, a magnetic hold down mechanism can be used, as well as a physical latching mechanism. A variety of mechanical latches can be implemented. 
     In some embodiments, the time delay is achieved via an air damper at the end of a long gear train. A standard rotary or linear damper, a leaky shock absorber, a friction damper, among other options, may be used as well. The presented gear train can be modified as well. A worm gear configuration, a cycloidal gearing configuration, and many others are also possible. The gear ratio can be changed as well in order to change the duration of the time delay of the delay system  54 . Also, there is no real winding of a timer occurring in the current embodiment, rather just a driving and non-driving phase. This could be reconfigured, such that the timer is sprung itself, rather than having the booster spring unit  62  driving the entire mechanism externally. However, one could consider the booster spring  62 , and everything downstream to be a single timer unit as well, and thus in that case, the timer does get wound by the main spring unit  66 . 
     Some embodiments couple the booster spring unit  62  to the main spring unit  66  in a way that allows the seat  1  to be user-lifted and have no effect on the delay system. The dog type coupling ( 63 ,  67 ) is preferred for this reason, however, if someone lifts the seat prematurely, the timer will not immediately return to its original state, and will have to run down as before. This may not be preferable in some instances, and as such, alternative linkages may be used. A barrel cam type linkage, a four-bar linkage, and many others not listed here may be used in advantageous configurations as well. 
       FIG.  31 A  schematically shows an alternative embodiment of the self-lifting toilet seat system  100  in accordance with illustrative embodiments of the invention. In various embodiments, a liquid moving under the force of gravity shifts the center of mass of the seat, causing the seat to rotate towards or away from the down position. Various embodiments may use a combination of mechanical elements, including a spring-loaded  9  hinge and liquid flow channels. Some embodiments may include a pneumatic lifter to augment or replace the spring-loaded hinge  9  and liquid flow channels (e.g.,  81 - 87 ). It will also be appreciated that other means of displacing the center of mass of the seat may be used, such as a counterweight system. However, illustrative embodiments using the spring-loaded hinge  9  and liquid flow channels advantageously provide reduced complication and expense in achieving the system of claim  1 . 
     As will be discussed in greater detail below, the delay system  54  expiration time may be modulated using a controlled flow of liquid  89  to temporarily counterbalance the self-lifting torque provided by the spring  9  of the lifting system  52  to provide a time delay before the seat  1  starts to rise. This liquid-based delay system  54  may provide a simple and passive embodiment of the self-lifting toilet seat system  100 . The present disclosure is therefore free of the complications of electrical or hydraulic controls, that may provide a fixed time delay, and that may require no user interaction to raise the seat (e.g., such as pressing a foot-activated switch). Accordingly, various embodiments may provide a passively activated mechanism. 
       FIG.  31 B  schematically shows a partially transparent toilet seat  1  with an internal flow loop for liquid flow in accordance with illustrative embodiments of the invention. In some embodiments, and as shown in  FIG.  32   , the internal flow loop may include a starting chamber  81 , forward flow channel  82 , frontal holding chamber  83 , return flow channel  85 , recovery chamber  86 , and reset channel  87 . 
     The toilet seat includes a liquid-controlled delay system  54 . Illustrative embodiments may provide a method and apparatus to delay the self-lifting action of the seat  1 . 
       FIG.  32    schematically shows a detailed view of the self-lifting toilet seat system  100  in accordance with illustrative embodiments of the invention. The lifting system  52  may be positioned within the hinge housing  3  of the toilet seat  1  or within the toilet seat  1  itself (e.g., within the transparent housing shown in  FIG.  31 B ). 
       FIG.  33 A  schematically shows the relative positions of the starting  81  and recovery  86  chambers when the seat  1  is in the down position  50 . The starting chamber  81  is offset vertically with respect to the recovery chamber  86 . This difference in elevation creates a driving force for liquid  89  flow away from the hinge towards the front of the seat when the seat  1  is user-lowered. 
       FIG.  33 B  shows the relative positions of the starting  81  and recovery  86  chambers when the seat  1  is in the up position  48 . The relative positions of the two chambers are reversed, with the recovery chamber  86  now higher than the starting chamber  81 . This elevation difference in this position creates a driving force for the reset flow through the reset channel  87 . 
     In the present disclosure, the liquid flow loop (e.g.,  81 - 87 ) is integrated into the seat  1 , and is partially filled with a liquid  89  (e.g., water with sterilizers and surfactants). The speed of the flow of this liquid  89  forward or backward through the channels of this loop, depending on the position of the seat  1 , provides the desired delay of the delay system  54  in self-lifting of the seat  1 . It will be appreciated that there are many other liquids  89  that may be used. In various embodiments, the system may include, among other things:
         A toilet seat hinge  46  with attachment blocks of substantially conventional dimensions that allow the seat to be bolted to the main body of the toilet bowl  44 .   A lifting spring  9  that is near the axle  7  of the hinge  46 . The strength of the spring  9  is just sufficient to lift the seat from the down position  50  when the front of it is empty of a sufficient mass of liquid  89 . In preferred embodiments, the spring  9  may be a coil spring concentric with the axis of the hinge  46 , or a linear spring on a lever arm.   A toilet seat  1  of substantially conventional shape with internal channels that form a flow loop substantially within the seat  1 . In illustrative embodiments, the internal channels do not extend past the dimensional envelope of a conventionally sold commercial or residential toilet seat  1 , as illustrated for example in  FIG.  31 B . The channels are angled with respect to a horizontal plane as described below ( FIGS.  34  and  35   ) so as to allow the flow of the liquid  89  forward or backward depending on the orientation of the seat  1 .
 
The self-lifting toilet seat  1  of the present disclosure may incorporate one or more complete flow loops as required for different applications. For applications requiring a full circular design (most commonly seen in residential bathrooms), a single flow loop would be preferred as shown in  FIG.  32   . For applications requiring a gap at the front (e.g., commercial bathrooms) the use of two complete and independent flow loop systems would be preferred, as illustrated in Figures
       

     Some embodiments include:
         One or more liquid flow loops located substantially within a toilet seat  1  of substantially conventional shape.   Two sections of the internal liquid flow loop that form a starting chamber  81  and a recovery chamber  86 .   Another section of the internal liquid flow loop that forms a front holding chamber  83 .   Two sections of the internal liquid flow loop that form a forward flow channel  82  and a return flow channel  85  ( FIG.  44   ).   A reset channel  87  ( FIGS.  40  and  44   ) that allows flow from the recovery chamber  86  to the starting chamber  81  when the seat  1  is in the up position  48 . An entry port  88  of this reset channel  87  may be elevated so as to prevent backflow to the recovery chamber  86  when a user begins self-lowering the seat  1  ( FIGS.  40  and  53   ).   A quantity of liquid  89  in the liquid flow loop. The liquid  89  may be water, and/or may contain a surfactant and anti-bacterial agent.   A flow constriction element  84  located in the flow channel between the front holding chamber  83  and the recovery chamber  85  as shown in  FIGS.  36  and  49 A- 49 B . The flow constriction element  84  may include a flow restriction orifice of substantially circular or rectangular cross-section. The cross-sectional area of the flow constriction  84  is set (or determined by experiment,  FIG.  37   ) to provide the desired pre-determined delay time (typically 5 to 60 seconds depending on the application) before the seat  1  self-lifts after the user-applied pressure is removed from the seat  1 .   A device such as a polymeric bumper, which may be incorporated into seat nubs  5  that serves to partially self-lift the seat  1  to the neutral state  49 A (when downward pressure is released by the user) and initiate the delay system  54 .   An optional damper element  19 ,  80  to control the rise rate of the seat  1  as it self-lifts and stop the seat  1  from heavily impacting the rear area of the toilet bowl as it self-lifts to the up position  48 .       

     The above components may be configured so as to provide a self-lifting toilet seat system  100  of simple construction and operation that provides a delay system  54  to delay self-lifting of the seat  1  so as to prevent secondary contact with the user as the toilet seat  1  self-lifts. 
     It should be appreciated that the illustrative embodiments may be used as replacements for existing toilet seats  1 . Toilet seats  1  are attached to the main body of the toilet bowl  44  by two simple bolts, spaced 5.5″ apart (an industry standard). The present disclosure may be mounted the same way, and thus be retrofittable to virtually all existing toilet bowls  44 . 
     It will be appreciated that any configurations of the above elements which provide the described functionality will not significantly deviate in look, size, and shape from a standard commercially or residentially sold toilet seat. The conformity of various embodiments of the toilet seat system  100  to a standard commercial toilet seat  1  is shown in the comparison of  FIGS.  47  and  48   . 
     It will be appreciated that similar elements, or elements that may perform similarly to those listed above may be used without departing from the scope of the present disclosure. Furthermore, in various embodiments, some or all of the components listed above may be modified and/or are optional. Furthermore, some components listed in the singular may include one or more of the components. 
       FIGS.  34 - 36    schematically show a process of activating the delay system  54  in accordance with illustrative embodiments of the invention.  FIG.  34    schematically shows the seat  1  in the down state  50 A in accordance with illustrative embodiments of the invention. In this position the flow channels are angled slightly downward to enable liquid to flow from the starting chamber  81  towards the frontal holding chamber  83 . 
     To describe the operation of the self-lifting seat system  100 , it may be assumed the seat  1  is initially in the up position  48 . To start the process, a user grasps the seat  1  (or a handle  2  on the seat, or a foot peg) and self-lowers it downwards into a down position  50  shown in  FIG.  34   . As the seat approaches the down state  50 A, liquid  89  from the starting chamber  81  may flow relatively quickly (over a period of about 0.5 to 2 seconds) towards the front of the seat  1  to the frontal holding chamber  83  due to the inclination of the forward flow channel  82  and the action of gravity. The mass of liquid  89  that becomes concentrated towards the front of the seat  1  creates a torque sufficient to counteract the self-lifting torque of the spring  9  of the lowering system  52 . This allows the seat  1  to remain (temporarily) in a down position  50  providing the user enough time to sit down on the seat  1  without the annoyance of having it begin self-lifting too early. Additionally, as there is no physical latch holding the seat  1  in the down position  50 , the user is able to easily self-lift the seat  1  into the up position  48  at any point during the operation of the seat  1 . 
     In various embodiments, when the user stops applying downward pressure on the seat  1 , and before sitting down, the seat will move to the neutral state  49 A , and thus self-lift slightly (preferably about 0.5 to 2.0 inches above the rim of the toilet bowl). In this embodiment, self-lifting to a very specific neutral state  49 A is necessary to ensure the channels end up at the correct orientation to promote fluid flow. Thus, an elastomeric (e.g., rubber or other material) bumper may be advantageously positioned near the hinge  46 , or as part of the nubs  5  such that it self-lifts the seat  1  to the desired neutral state  49 A at the point where the bumper is in the uncompressed state. 
     In the neutral state  49 A of  FIG.  35   , the liquid-based delay system  54  is activated. The neutral state  49 A changes the inclination of the return channel  85  so that liquid  89  begins to flow back to the recovery chamber  86  through a flow orifice  84  as shown in  FIG.  36   . When a sufficient quantity of liquid  89  is thus transferred to the recovery chamber  86  at the rear of the seat  1 , the liquid  89  remaining in the front holding chamber  83  will no longer be sufficient to overcome the self-lifting torque of the spring  9 , and the seat  1  begins to self-lift. Thus, the time delay refers to the delay before the seat begins to self-lift towards the up position  48 , not necessarily the total time it takes for the seat  1  to reach to up position  48 . 
     The delay system  54  delay time of this mechanism is determined by a number of engineering factors, including the rate of liquid  89  return flow. In general, higher rates of liquid return flow are associated with shorter delay times and vice-versa. In some embodiments, the rate of liquid  89  flow (and hence the delay time) is set in the system by a flow constriction of limited area  84  (effectively a small orifice) positioned between the front holding chamber  83  and the recovery chamber  85 , as shown for example in  FIGS.  36  and  50   . 
       FIG.  37    shows a chart of measured and extrapolated time delay data plotted against a cross-sectional area of a flow constriction orifice  84  of rectangular cross section. In this case, a constriction area of, for example, 4 square millimeters (mm 2 ), would produce a delay time of about 50 seconds. A larger area of 12 mm 2  would produce a delay time of about 10 seconds. 
     It will be appreciated that while the present disclosure is discussed with a toilet seat  1  to provide a time delay of from 1 to 120 seconds (with a preferred range of 5 to 60 seconds), other delay times may be used without departing from the present disclosure (e.g., up to several minutes if desired). 
       FIG.  38    schematically shows a rotary damper  19  in accordance with illustrative embodiments of the invention. The rotary damper  19  may be connected to the shaft  7  of the toilet seat hinge  46  by means of connecting gears. 
     As the liquid  89  drains from the front holding chamber  83  and the seat  1  starts to self-lift, there may be cases in which the seat self-lifts too rapidly due to the action of the lifting system  52  (E.g., spring). To control the self-lift rate, a damper  19  may be used. 
       FIG.  39    schematically shows the seat in the up position  48  in accordance with illustrative embodiments. In this position, the recovery chamber  86  is offset vertically with respect to the starting chamber  81  to provide a driving force for reset flow to the starting chamber  81  in preparation for the next cycle. 
       FIG.  40    schematically shows a close-up view of the liquid reset channel  87  that connects the recovery chamber  86  with the starting chamber  81  in accordance with illustrative embodiments. In this view, the seat  1  is in the down position  50 . When the seat  1  is later self-lifted to the up position  48 , liquid  89  from the recovery chamber  86  will pass through this reset channel  87  to the starting chamber  81  in preparation for the next cycle. 
     A 3-dimensional geometric arrangement of the recovery  86  and starting chambers  81  may be employed such that when the seat  1  is in the down position  50 , the elevation of the starting chamber  81  is higher than that of the recovery chamber  86  ( FIG.  33 A ); and when in the up position  48 , the relative elevations are reversed such that the elevation of the recovery chamber  86  becomes higher than that of the starting chamber  81  ( FIGS.  33 B and  39   ). 
     An example feature of this design is that the flow from the reset channel  87  may enter the starting chamber  81  through an elevated port  88 . The shape of this port  88  may form an inverted “J”, as shown in  FIG.  40   . The elevated port  88  may not affect the reset flow when the seat  1  is in the up position  48 , but it provides an effective means of preventing the backflow of liquid to the recovery chamber  86  that would otherwise occur when the seat is subsequently lowered to the down position  50  at the start of the next cycle of usage. 
     Illustrative embodiments provide a liquid based delay system  54  to achieve a time delay before the seat  1  self-lifts to the up position  48 . As described above, the delay system  54  may begin when the downward force from the user on the seat  1  is released, the seat self-lifts to the neutral state  49 A , thus having an initial self-lifting amount (e.g., 0.5 to 2 inches). The initial self-lifting initiates the flow of liquid  89  from the front of the seat  1  towards to hinge  46  though a small opening  84 (or orifice). Like the neck of an hourglass, the size of the orifice controls the flowrate. 
     The overall delay system  54  timing may be set by the size of the orifice  84  and the quantity and viscosity of liquid  89  that flows. This “transfer quantity” is the amount of liquid  89  that shifts the center of gravity sufficiently to counteract the torque of the self-lifting spring  9 . The transfer quantity will vary for different applications, as can be determined by straightforward methods by those skilled in the art. In general, the transfer quantity is a function of variables such as the torque of the spring  9 , density of the liquid  89 , and the displacement over which the liquid  89  flows front-to-rear as the seat  1  moves through its cycle. 
     Various embodiments of the liquid flow loop of the self-lifting toilet seat system  100  may include:
         One-Way Rotary Dampers: As mentioned previously, the rotary dampers  19  used in illustrative embodiments may be one-way dampers. They may be oriented such that they provide effective damping only as the toilet seat  1  is self-lifted and no damping (or very low damping) as the toilet seat is user-lowered. Dampers  19  should not affect the force distributions about the hinge  46 , but rather just slow the motion of the seat  1 .   Handles or foot-pegs: The toilet seat used in various embodiments may incorporate one or two handles  2  or one or two foot-pegs to enable the user to user-lower the seat  1  without touching the main body of the seat  1 .   Top Stop: The housing structure used in various embodiments may provide a positive stop to the upward motion of the seat at the up position  48 . The stop prevents the seat  1  from rotating too far as it self-lifts.       

     Furthermore, various embodiments may use a variety of liquids  89 . It should be understood that the higher the liquid  89  density, the less volume is needed to sufficiently change the torque of the seat  1  to overpower the lifting system  52 . Water is the preferred liquid  89  because it has relatively high mass density, is non-toxic, and inexpensive. Water is also non-permeable through most plastic materials used in the fabrication of toilet seats  1 . In some embodiments, an anti-foaming agent or surfactant may be added to the water to decrease the liquid surface tension, and a disinfectant may be added to keep bacteria from proliferating inside of the seat  1 . 
     Some embodiments may further use the liquid  89  itself to help self-lift the toilet seat (e.g., in addition to, or as an alternative to, the spring  9  of the lifting system  52 ). Various embodiments position the recovery chamber  86  some distance behind the axle  7  of the toilet seat hinge  46 . With such a positioning, the mass of liquid  89  entering the recovery chamber  86  provides a torque to add to the torque provided by the spring  9  of the lifting system  52 . In such embodiments, however, it is envisioned that the recovery chamber  86  extends outwardly from the side of the toilet seat  1  in order to provide sufficient clearance between the seat  1  and the toilet bowl base  44 , so as to enable the full range of angular motion of the seat  1 .
         Use with open front toilet seats  1 : In some embodiments, the delay system  54  of the present disclosure may be used in the toilet seat  1  with an open front, as required for use in many commercial applications and shown in  FIG.  47   . In such implementations, the flow channels  82  and  85  that connect the starting  81  and recovery chambers  86  to the frontal holding chamber  83  may both be incorporated along the same side of the seat  1  (left or right side). In other implementations, there may be two such pairs of channels, one pair running along the left side and the other along the right side of the seat  1 .       

     It will be appreciated that one or more components may be optional without departing from the scope of the present disclosure. Furthermore, it will be appreciated that although illustrative embodiments operate with toilet seats  1  having a gap, some other embodiments may have a toilet seat  1  without a gap. 
       FIG.  41    schematically shows a split open view of an internal channel geometry in accordance with illustrative embodiments. Here, the toilet seat  1  has a gap at the front ( FIG.  31 A ), as compared to a closed front design ( FIG.  31 B ). The gap towards the front of the seat complies with the regulatory (ADA and IPC) codes. The single liquid flow loop of the previous design has been reallocated to two separate sides of the seat  1 , with one complete loop on each side of the gap. In some embodiments, these two loops are completely separate, each as a closed environment to themselves (Thus, there is no mixing of liquid  89  between the two loops). In other embodiments, the two loops may share a common starting  81  and/or recovery chamber  86 . 
       FIG.  42    shows a transparent view of the toilet seat  1  in accordance with illustrative embodiments. The gap model is more robust compared to the single flow loop used in the closed seat design, as there is less volume in the frontal holding chamber  83  for liquid  89  to slosh back and forth. This sloshing motion could cause the seat  1  to temporarily bounce up and down when first lowered by the user, thus forcing the user to continue applying a force to the seat  1  for some additional time until the liquid  89  motion subsides. With the reduced volume, it is expected that the seat  1  beomes steady (while held in the down state  50 A) within 1 second or less under most circumstances. 
       FIGS.  43 A- 43 B  shows a cross-sectional view of the front holding chamber  83  of  FIG.  41   , in which the toilet seat  1  has an open front. 
       FIG.  44    provides a cross-sectional view of the two independent flow loops that may be used in some embodiments. In the figure, liquid  89  is shown in one of the starting chambers  81  with the seat  1  in the up position  48 . In this position, the seat is prepared for a user to begin lowering the seat  1 . 
       FIG.  45    schematically shows a side view with a curved line from the starting chamber  81  to the frontal holding  83  chamber in accordance with illustrative embodiments. The shape of the forward flow channel  82  of the toilet seat  1  may approximate a “curve of maximum descent” (also known as a Brachistochrone curve), which is shown as the blue curve in the figure. The advantage with this shape is that the liquid  89  in the starting chamber  81  flows more quickly to the frontal holding chamber  83  when the seat  1  is lowered, which minimizes the time that the seat  1  is held down by the user before the delay system  54  is active. 
       FIG.  46    schematically shows a cut open view of the toilet seat  1  in accordance with illustrative embodiments of the invention. As shown, the internal flow loop may be shaped to conform within the shape of the seat  1 . This provides a consistent wall thickness that benefits the molding process that may be used in the manufacture of the commercial seats. For those familiar with the injection molding process, it is well known that a consistent wall thickness provides dimensional stability for the finished articles (i.e., minimal shrinkage and warping on cooling). A consistent wall thickness also reduces the amount of plastic required to fabricate the seat  1  as well as the weight of the finished article. 
       FIG.  47    schematically shows a top view of an industry standard shaped toilet seat  1 .  FIG.  53    schematically shows a top view of the toilet seat  1  in accordance with illustrative embodiments of the invention. As seen in the comparison, illustrative embodiments have a similar shape to existing toilet seats land may be retrofitted onto existing toilets  40 . 
     Various embodiments may be manufactured using a variety of methods. For example, a clamshell method may be used, where top and bottom portions of the seat  1  are molded separately, and then bonded together to create a finished seat  1 . Other methods include over-molding, where the internal flow channels are formed to the correct shape in a blow molding process, and then over-molded with a second plastic to form a completed seat  1 . Yet another method may include a sandwich method, which is a combination method in which blow molded internal channels are enclosed within (separately molded) top and bottom portions of an outer shell. 
       FIGS.  49 A- 53    schematically show the liquid- flow  89  process of using the toilet seat  1  in accordance with illustrative embodiments. It may be noted that this process is greatly simplified from a longer process that normally would be used to use the self-lifting toilet seat. Accordingly, the process of self-lifting the toilet seat  1  likely has many steps that those skilled in the art likely would use. In addition, some of the steps may be performed in a different order than that shown. Additionally, or alternatively, some of the steps may be performed at the same time, or skipped entirely. Those skilled in the art therefore can modify the process as appropriate. 
       FIG.  49 A  shows the seat  1  in the down state  50 A with pressure applied by the user. This pressure may be hand-applied pressure applied by the user (prior to sitting down), or it may be the weight of the user when sitting on the seat  1 . In this state, liquid  89  from the starting chamber  81  flows by gravity towards the front of the seat  1  through the forward flow channels  82  and accumulates in the front holding chamber  83 . In the down state  49 A, the frontal holding chamber  83  is vertically lower than either the starting chamber  82  or the recovery chamber  86 . Thus, the liquid  89  remains pooled in the frontal holding chamber  83  due to gravity until user pressure is removed from the seat. 
     In some embodiments, the forward flow channel  82  or the front holding chamber  83  may contain one or more baffles  90  to limit the rate of flow of liquid  89  through the forward flow channel  82  as the seat  1  is lowered for use by the user. Such baffles  90  have been found desirable for use in some embodiments to prevent excessive sloshing of the liquid  89  as it rushes forward through the forward flow channel  82  into the front holding chamber  83 . It has been found that, in some cases, such sloshing of liquid  89  can cause an undesirable bouncing of the seat  1  up and down after it is first lowered for use. 
       FIG.  49 B  shows the seat in the neutral state  49 A after the user-applied pressure is removed, such as when the user stands up. In this position, the delay system  54  is active, and the seat  1  is temporarily prevented from self-lifting due to the weight of liquid  89  contained in the front holding chamber  83 . In this condition, the weight of liquid  89  in the front holding chamber  83  is sufficient to overcome the self-lifting torque of the spring  9  of the lifting system  52 . 
     With the seat in the neutral state  49 A, the liquid  89  in the front holding chamber  83  begins flowing (relatively slowly) through a flow limiting orifice  84  to a recovery chamber  86  located near the hinge  46  of the seat  1 , as illustrated in  FIG.  50   . When a sufficient quantity of liquid  89  has been transferred from the front of the seat to the recovery chamber  86 , the torque of liquid  89  remaining in the front holding chamber  83  becomes insufficient to counteract the self-lifting torque of the lifting system  52 , and the seat  1  self-lifts to the up position  48 ,  FIG.  51   . The duration of the delay system  54  is thus controlled by the rate of flow, and hence the size of the flow-limiting orifice  83 . 
     If the seat  1  is user-lowered to the down state  50 A before enough liquid  89  has flowed from the frontal holding chamber  83  to the reset chamber  86  in order to allow the lifting system  52  to self-lift the seat, then the liquid  89  will flow back into the frontal holding chamber  83 . The vertical displacement of the frontal holding chamber  83  relative to all the other channels when the seat  1  is in the down state  50 A is the driving reason behind this “reset” flow. Thus, the delay system  54  may be reset by the application of user force to the seat  1 . 
       FIG.  52 A  shows the liquid  89  accumulation in the recovery chamber  86  immediately after the seat  1  rises to the up position  48 . Because of the elevated position of the recovery chamber  86  with respect to the starting chamber  81 , a “reset” flow of liquid is enabled through a reset channel  87  to the starting chamber  81  in preparation for the next cycle of use. The liquid  89  pools or rests in the starting chamber  81 , as shown in  FIG.  52 B . 
       FIG.  53    is a rear cutaway view showing liquid  89  in the starting chambers  81  immediately after the seat  1  is lowered for the next cycle of use. Because the entry ports  88  from the reset channels  87  are elevated with respect to the starting chambers  81  (as shown), liquid  89  is prevented from back-flowing into the recovery chamber  86 , and is therefore forced to flow, as intended, towards the frontal holding chamber  83  at the front of the seat. 
     It should be understood that various embodiments provide a number of advantages. Illustrative embodiments advantageously eliminate the need for side tanks employed in prior art implementations of the liquid displacement method. Furthermore, various advantages include that the system may prevent the seat  1  from self-lifting as soon as the seat is user-lowered. Various embodiments do not require user interaction to self-lift the seat  1  after use (e.g., the system  100  may be passive), thereby reducing the likelihood of future users soiling the seat. Furthermore, various embodiments provide a simplified and elegant solution that does not involve complicated electronic components that are costly and vulnerable to durability-related failure. Aesthetically, the toilet seat  1  may appear similar to an ordinary toilet seat, without requiring the use of a large gearbox or other lifting system  52  that cannot fit into the hinge  46  of the product. In some embodiments, the toilet seats  1  are retrofittable to standard toilets  40  because by having industry standard mounting points. Thus, some embodiments may simply provide a retrofittable toilet seat  1 (as opposed to an entire toilet system). 
     As mentioned at the beginning of the disclosure, another embodiment of the toilet seat system  100  exists wherein the lifting system  52  becomes a lowering system  52 . The lifting system  52  and/or delay system  54  may be flipped in orientation, such that the delay system  54  is engaged when the seat  1  is in the up position  48 , and the lifting system  52  is instantiated as a lowering, rather than lifting, system. The lowering system  52  may be preferred in the home and residential environments, where a user may be more likely to user-lift the seat  1  to urinate, but then fail to user-lower the seat  1  after use. Thus, in some embodiments, when the seat is user-lifted to the up position  48 , the suction cups  13  engage and hold it in the up position  48  for anywhere from 1 second to 5 minutes, after which the delay mechanism  54  disengages, and a lowering system  52  self-lowers the seat  1  into the down position  50 . The user may reset the time delay at any point in the cycle by simply user-lowering the seat to the down position. A damping system (e.g.,  19 ,  80 ) may be added to prevent the seat  1  from slamming into the toilet bowl  44  upon self-lowering, such as a one-way rotary damper. 
     As with the suction cup  13  and plate  14  self-lifting embodiment, it should be understood that the position and/or dimensions of the plate  14 , as well as the internal linkages (e.g.,  10 , 11 , 12 ), position, and size of the suction cup  13  may be tuned to engage at any point along the transition of the seat  1  from the down position  50  to the up position  48  of the self-lowering embodiment. 
     In the illustrative embodiments, the up position  48  is a general callout to the location of the seat  1 , regardless of system states. In various embodiments, in the up position  48 , the bottom plane of the seat  1  is substantially perpendicular to the top plane of the bowl  44  (e.g., vertical or at an acute angle to vertical—about 80-115 degrees from the down position). 
     The down position  50  is a general callout to the location of the seat  1 , regardless of system states. In the down position, the bottom plane of the seat  1  is substantially parallel to the top plane of the bowl  44  (e.g., about −15 degrees to about 25 degrees from horizontal). For self-lowering configurations, in the down position  50 , the seat  1  is at its resting position unless an outside force is applied (e.g., by a user sitting or lifting the toilet seat  1 ). 
     In the up state  48 A a user force is applied sufficient to hold the seat  1  in the up position  48 . In the up state  48 A, the delay system  54  is engaged, and the time delay begins right after or concurrently with the toilet seat  1  entering the neutral state  49 B (e.g., after the user removes their applied force from the toilet seat  1 ). In various embodiments, the time delay  54  may be reset or paused by the user forcing the seat back to the up state  48 A. 
     In self-lowering embodiments, the neutral state  49 B is the state of the seat  1  after the seat  1  has been user-lifted to the up state  48 A and there is no more user applied force to the seat  1 . In the neutral state  49 B, the user force is removed and the delay system  54  applies a force to hold the seat  1  in the up position  48  until a predetermined time delay expires. The delay system  54  temporarily prevents the lowering system  52  from self-lowering the toilet seat  1  to the down position  50 . The angular location of the seat  1  about hinge  46  relative to the top plane of the bowl  44  with such a loading case is the neutral position. Although still considered to be in the up position  48 , the neutral state  49 B may, in some embodiments, have an angular offset of between about 0 and about 20 degrees from the position of the toilet seat in the up state  48 A. 
     For illustrative embodiments configured to be self-lowering, the seat  1  may be either in the neutral state  49 B or the up state  48 A and still considered to be in the up position  48 . For the self-lowering toilet seat system  100 , the seat is “self-lowered” when the lowering system  52  applies a force sufficient to transition the seat  1  from the up position  48  to the down position  50 . When a user lifts the seat  1  from the down position  50  and forces it to the up state  48 A, this is referred to as “user-lifting” the seat. 
       FIG.  15    shows a process of self-lowering the toilet seat  1  in accordance with illustrative embodiments of the invention. The process begins at step  1502 , which provides the toilet seat system  100  as described herein. In various embodiments, the toilet seat system  100  includes the toilet seat  1 , the toilet bowl  44 , and the hinge  46 . In some embodiments, the toilet bowl  44  may already be installed at a desired location. Therefore, the system may include the toilet seat  1  and the hinge  46 , which may be retrofitted to couple with the toilet bowl  44 . In various embodiments, the hinge  46  (e.g., the housing  3  and housing base  4 ) may be configured to bolt or otherwise couple with the toilet bowl  44 . As discussed below, the hinge  46  also couples to the seat  1  and preferably allows the seat  1  to move and/or rotate relative to the bowl  44 . 
     In various embodiments, the hinge  46  preferably includes a housing  3  and housing base  4 . Preferably, the housing  3  and housing base  4  are sealed and waterproof. Preferably, the rotation of the axle  7  is also sealed via rotary seal  17 . Inside of the housing  3  and housing base  4  is the delay system  54 . Additionally, the housing  3  and housing base  4  may contain the lifting system  52  and the linkages (e.g.,  10 - 12 , 30 - 33 ). In some embodiments, as shown in  FIG.  8   , the cup  13  and the plate  14  is further isolated within this housing  3  using a bellows  55  or other seal that encloses the plate  14  and cup  13  in a fully dustproof manner while continuing to allow the full range of motion of the suction cup  13 . 
     At step  1504 , the user lifts the toilet seat  1 . When the toilet seat  1  is user-lifted, the lowering system  52  begins to provide a counter torque to the seat  1  towards the down position  50 . At some point during the lifting of the seat  1 , preferably when the seat approaches or reaches the up state  48 A, a delay system  54  engages, causing the toilet seat  1  to remain in the in the up state  48 A until the user removes their applied force from the seat  1 . 
     The process then proceeds to step  1506 , which begins the time delay once the user&#39;s applied lifting force is removed. When the user applied lifting force is removed, the seat will transition to the neutral state  49 B due to the torque applied to the system by the lowering system  52 , which is configured to overcome the torque of the seat  1  when the time delay of delay system  54  expires. As described previously, the delay system  54  may include a suction cup  13  and a plate  14 . In some other embodiments, the delay system  54  may include some other type of adhesive. Furthermore, some embodiments may include a gear- based delay system or a fluid-channel based delay system  54 , as described in alternative embodiments further below. 
     At step  1507 , the process asks whether a user decides to lower the seat back into the down position? If so, the toilet seat system is transitioned by the user back into the down position and the process is complete at step  1516 . If not, the process continues to step  1508 . At step  1508 , the process asks whether a user re-applies lifting force before the time delay expires? If so, in some embodiments, the time delay is reset. However, in some other embodiments, the time delay is paused as the user re-applies their force. Thus, if a user lifts, or otherwise applies a threshold lifting force to the toilet seat  1  prior to the expiration of the delay system  54 , the toilet seat  1  will not self-lower via the lowering system  52  to the down position  50 . Instead, the process moves to step  1510  where the delay system will experience a reset or pause to its delay. 
     After the user has finished re-applying a lifting force to the toilet  40  in step  1512 , the user may continue using the toilet  40 . This causes the seat  1  to transition down to a neutral position  49 B.  FIGS.  54 A- 54 C  schematically show the seat  1  in different positions.  FIG.  54 A  schematically shows the seat  1  in the up state  48 A.  FIG.  54 B  schematically shows the seat  1  in the neutral state  49 B, and  FIG.  54 C  schematically shows the seat  1  in the down position  50 . To that end, some embodiments may include a component that moves the seat  1  back to the neutral position  49 B as soon as the user removes their user-lifting force (i.e., before the time delay expires). Additionally, or alternatively, the delay system  54  may have some slack that causes the seat  1  to move to the neutral position  49 B as the user removes their lifting force. 
     After the user removes force from the seat in step  1512 , the system loops back to step  1506  and the delay system  54  resumes or restarts, after which the process once again asks whether a user lowers the seat. If not, the system once again asks if the user applies force before the time delay expires. If they do, the cycle continues as described above, however, if a user does not otherwise apply a threshold lifting force to the toilet seat  1  prior to the expiration of the delay system  54 , the process moves to step  1514 , and the toilet seat  1  will self-lower to the down position  50 , and the process is complete at step  1516  with the seat in the down position. 
     Additionally, the user may reset the seat  1  to the down position at any point in the cycle, for example at intermediate steps  1505  or  1509 . 
       FIG.  15    describes a method of self-lowering a toilet seat  1  in accordance with illustrative embodiments of the invention. It should be noted that this method is substantially simplified from a longer process that may normally be used. Accordingly, the method shown in  FIG.  15    may have many other steps that those skilled in the art likely would use. In addition, some of the steps may be performed in a different order than that shown, or at the same time. Furthermore, some of these steps may be optional in some embodiments. Accordingly, the process  1500  is merely exemplary of one process in accordance with illustrative embodiments of the invention. Those skilled in the art therefore can modify the process as appropriate. 
     In  FIG.  55 A , a rear perspective view of the seat  1  is shown in the down position  50 .  FIG.  55 B  shows a front perspective view of the seat  1  in the up position  48 . 
       FIGS.  56 A- 56 C  schematically show the self-lowering toilet seat system  100  as it lifts from the down position  50  in  FIG.  56 A , to the neutral state  49 B in  FIG.  56 C , to the up state  48 A in  FIG.  56 C . 
     As used in this specification and the claims, the singular forms “a,” “an,” and “the” refer to plural referents unless the context clearly dictates otherwise. For example, reference to “the suction cup” in the singular includes a plurality of suction cups, and reference to “the plate” in the singular includes one or more plates and equivalents known to those skilled in the art. Thus, in various embodiments, any reference to the singular includes a plurality, and any reference to more than one component can include the singular. 
     While various inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. 
     It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Illustrative embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure. Disclosed embodiments, or portions thereof, may be combined in ways not listed above and/or not explicitly claimed. Thus, one or more features from variously disclosed examples and embodiments may be combined in various ways. For example, it is to be understood that the present disclosure contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment. 
     Various inventive concepts may be embodied as one or more methods, of which examples have been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments. 
     Although the above discussion discloses various exemplary embodiments of the invention, it should be apparent that those skilled in the art can make various modifications that will achieve some of the advantages of the invention without departing from the true scope of the invention.