Abstract:
A damping device for damping the relative rotation of a rotating member. The damping device includes a casing, a rotor disposed in an interior space of the casing, and a damping mechanism including a viscous liquid disposed in an annular chamber formed between the casing and the rotor. The viscous liquid exerts frictional forces to damp the relative rotation between the rotor and the casing in a first rotation direction but not in the opposite rotation direction, the damping force increasing when the rotor and the casing rotate relative to each other from a first relative angular position to a second relative angular position in the first rotation direction. The casing and the rotor are structure to provide a damping force by impeding the flow of the viscous liquid within the chamber, and to provide another damping force by the contacting of the rotor and the casing. A valve is further provided within the chamber to restrict the flow of the viscous liquid. A toilet seat and lid unit incorporating two identically shaped damping devices, as well as a toilet bowl incorporating the seat and lid unit are also provided.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a damping device for toilet seat or toilet lid in a western-style toilet, and a toilet equipped with the damping device. 
     2. Description of the Related Art 
     In some high-quality western-style toilets, in order to prevent an impact sound from occurring when the toilet seat or lid is dropped, damping devices (or slow-closing devices) have been provided on the axis of rotation of the toilet seat or toilet lid in order to mitigate the force of rotational motion. For example, in the toilet seat and toilet lid opening/closing device disclosed in Japanese Unexamined (Kokai) Patent Application No. Hei 4[1992]-259424, as shown in FIG. 26, hinges  202  and  203  for the toilet seat  201  and hinges  205  and  206  for the toilet lid  204  are placed side-by-side, and opening and closing devices  207  and  208  that have damping functions are provided outside these hinges. 
     With this opening and closing device, a driving force transfer hole  210  such as a square hole is formed in one of the hinges  202  of the toilet seat  201 , and a driving force non-transfer hole (not shown in the figure) that does not transfer drive force is formed in the other hinge  203 . In addition, a driving force non-transfer hole (not shown in the figure) is formed in one of the hinges  205  for the toilet seat cover  204 , and a drive force transfer hole  212  is formed in the other hinge  206 . Thus, one of the hinge pins  215  links the hinge  202  of the toilet seat  201  and one of the opening-closing devices  207 , and the other hinge pin  216  links the hinge  206  of the toilet lid  204  and the other opening/closing device  208 . As a result, the rotation of the toilet seat  201  in the downward direction is damped by one of the opening/closing devices  207 , and rotation of the toilet lid  204  in the downward direction is damped by the other opening-closing device  208 . 
     Another opening/closing device for toilet seats or toilet lids is disclosed in Japanese Kokai Patent Application No. Hei 8[1996]-117148, shown in FIG.  27 . An attachment member  222  is fastened to the toilet  221 , and opening/closing devices  223 ,  224  having symmetrical orientations are inserted into the attachment member  222 . Hinges  225  that constitute the attachment parts for the toilet seat are then disposed on both sides of the attachment member  222 , and hinges  226  that constitute the attachment parts for the toilet lid are disposed on both sides of hinges  225 . An attachment pin  227  is attached on the side of the opening/closing device  223 , and an attachment pin  228  is attached on the side of the opening/closing device  224 , while passing through the hinges  225  and  226 . 
     On the other hand, with common western-style toilets, a variety of integrated toilet seat and lid units having different shapes or colors are available, and may be interchangeably installed on toilets. In the United States in particular, these types of toilet seat/toilet lid units are sold at low cost, and users may obtain toilet seat/toilet lid units that match their personal preferences. It is common for users themselves to dispose of old units, and use screws to attach the newly purchased unit. This attachment is carried out by providing an attachment member having a retention part that retains the rotating shaft and fastening flange between the hinge part of the toilet lid and hinge part of the toilet seat, so that attachment may be carried out by fastening this attachment member to the toilet. With toilets on which this type of toilet seat/toilet lid unit is installed, there is no damping mechanism on the side of the toilet to which it is attached, and a loud impact noise is produced when the toilet seat or toilet lid is released when closing the toilet seat, etc. Moreover, damage due to the impact of dropping ensues whereby the hinge parts are broken or the toilet seat or toilet lid is broken. 
     The opening/closing devices  207 ,  208  in the opening/closing device for toilet seats and toilet lids disclosed in Japanese Unexamined (Kokai) Patent Application No. Hei 4[1992]-259424 (FIG. 26) have a format whereby they are attached to the side surface of the toilet. This format generally involves attachment to the base cover of a warm water bidet-type toilet seat disposed on both sides of the toilet. For this reason, it is difficult to attach the opening/closing devices  207 ,  208  with toilets that do not have warm water bidet-type toilet seats. Moreover, the hinge  202  of the toilet seat  201  and the hinge  205  of the toilet lid  204  are in close contact, and the hinge  203  of the toilet seat  201  and the hinge  206  of the toilet lid  204  are in close contact, so there is the danger that the toilet lid  204  will also tend to move downward due to frictional forces when the toilet seat  201  is moved downward. 
     Moreover, the opening/closing devices  207 ,  208  are disposed with mirror symmetry, so they are not identical in terms of their damping directions. Specifically, the directions of action of the damping functions must be opposite, so the devices must be structurally different. For this reason, the cost of the opening/closing devices  207  and  208  increases. Moreover, it is necessary not to mistake the left and right parts when attaching them, and assembly errors may easily occur. 
     Moreover, with the opening/closing device for toilet seats and toilet lids of the toilet disclosed in Japanese Kokai Patent Application No. Hei 8[1996]-117148 (FIG.  27 ), the opening/closing devices  223 ,  224  must have a large attachment member  222 , so the space for sitting on the toilet  221  is decreased. Moreover, the hinges  225  and  226  are in contact on one side, and the hinges  225  and  226  are also in contact on the other side, so that the same problem occurs as in Japanese Kokai Patent Application No. Hei 4[1992]-259424 described above. Moreover, the opening/closing devices  223 ,  224  are disposed with mirror symmetry, so the damping direction is not the same for the left and right sides, as with the opening/closing devices  207 ,  208 . For this reason, the same problems arise in this regard as in Japanese Kokai Patent Application No. Hei 4[1992]-259424 described above. 
     Thus, with conventional opening/closing devices, a spring member is provided on the rotating shaft, which strongly applies a damping force in the final range when a toilet seat or toilet lid undergoes rotational falling, but the structure is complicated, large, costly and difficult to assemble. Moreover, fine response to changes in operating torque of the rotating member is problematic, and it is thus difficult to produce a high-quality feel during use. On the other hand, replaceable toilet seat/toilet lid units, while may be readily removed and attached according to personal preference, have no damping function. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a damping device for toilet seat and lid unit that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. 
     An object of the present invention is to provide a damping device for a toilet seat/toilet lid unit in a western-style toilet that is easy to install and has a simple structure and low cost. 
     Another object of the present invention is to provide a damping device for a toilet seat/toilet lid unit in which parts with the same shape and same structure may be attached as-is at the left and right attachment points using two damping devices. 
     Yet another object of the present invention is to provide a damping device for a toilet seat/toilet lid unit in which control of the rotational force of the seat and/or lid is gradually increased with the rotation of the toilet seat and/or lid. 
     Additional features and advantages of the invention will be set forth in the description which follows and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention provides a damping device including a casing, a rotor disposed in an interior space of the casing to form an annular chamber between the casing and the rotor, and a damping mechanism including a viscous liquid disposed in the chamber, the viscous liquid exerting frictional forces to damp the relative rotation between the rotor and the casing in a first rotation direction, the damping force increasing when the rotor and the casing rotate relative to each other from a first relative angular position to a second relative angular position in the first rotation direction. The damping mechanism does not damp the relative rotation of the rotor and the casing in the direction opposite the first rotation direction. 
     In particular, the casing has at least one protrusion protruding inwardly from the interior surface to the interior space. The rotor has a core with a radius that varies angularly such that the core and the protrusion of the casing forms a gap when the rotor and the casing are at the first relative angular position, and the core and the protrusion come into contact when the rotor and casing rotate relatively from the first relative angular position to or near the second relative angular position, whereby the contact generates a damping force that impedes the relative rotation of the rotor and the casing in the first rotation direction. Further, the protrusion of the casing extends in an axial direction and divides the annular chamber into at least two parts. The viscous liquid flows between the parts of the chamber through the gap between the protrusion and the core of the rotor when the rotor and the casing rotate relatively, and the protrusion impedes the flow of the viscous liquid to generate a damping force that impedes the relative rotation of the rotor and the casing. The interior space defined by the casing may have a radius that decreases with an angular position within an angular range. 
     In addition, the damping device includes at least one movable valve disposed within the annular chamber between the casing and the core of the rotor and controlling the flow of the viscous liquid within the chamber, the valve being latched to a retaining part of a protrusion of the rotor and moves with the rotor, a latching position of the movable valve changing with the direction of rotation of the rotor. The casing further has an end portion substantially perpendicular to a rotation axis of the rotor and the casing, where a depression is provided on an inner surface of end portion, the depression having a cross-sectional area in the radial direction that varies with an angular position defined on the casing. 
     According to another aspect of the present invention, a toilet seat and toilet lid unit is provided which incorporates the damping device, where the rotation of the toilet seat and/or lid is damped by the damping device. The toilet seat and toilet lid each have two hinges, and one damping device is disposed between one seat hinge and one lid hinge, and another damping device is disposed between the other seat hinge and the other lid hinge. The two damping devices have the same external appearance. 
     According to yet another aspect of the present invention, a western-style toilet bowl is provided having toilet seat and toilet lid unit which incorporates the damping device. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of the toilet seat/toilet lid unit including the damping device according to an embodiment of the present invention. 
     FIG. 2 is a partial cross-sectional plan view showing the structure of the periphery of the hinge for the toilet seat/toilet lid unit of FIG.  1 . 
     FIG. 3 is an axial cross-section of the damping device used in the toilet seat/toilet lid unit of FIG. 1, showing a state in which the movable valve has been removed. 
     FIG. 4 is a partial cross-sectional side view from the direction of the arrow A in FIG.  3 . 
     FIG. 5 is a front view of the inside of the casing of the damping device used in the toilet seat/toilet lid unit of FIG.  1 . 
     FIG. 6 is a front view showing the inside of the cover of the damping device used in the toilet seat/toilet lid unit of FIG.  1 . 
     FIG. 7 is a front view showing the rotor in a condition in which the movable valve of the damping device used in the toilet seat/toilet lid unit of FIG. 1 has been removed. 
     FIG. 8 is cross-sectional view along the line A—A in FIG.  7 . 
     FIGS.  9 (A) and (B) show the movable valve of the rotor part for the damping device used in the toilet seat/toilet lid unit of FIG. 1, where FIG.  9 (A) is a plan view and FIG.  9 (B) is a side view from the direction of the arrow B in FIG.  9 (A). 
     FIG. 10 is an exploded perspective view of the rotor part of the damping device used in the toilet seat/toilet lid unit of FIG.  1 . 
     FIGS.  11 (A)-(C) illustrate the function of the damping device used in the toilet seat/toilet lid unit of FIG. 1, where FIG.  11 (A) shows the condition when the toilet seat and lid are closed, and FIG.  11 (B) shows the condition when the toilet seat and lid are being opened, and FIG.  11 (C) shows a completely opened condition. 
     FIGS.  12 (A)-(C) illustrate the damping device used in the toilet seat/toilet lid unit of FIG. 1, where FIG.  12 (A) shows the condition when the toilet seat and lid are open, FIG.  12 (B) shows the condition when the toilet seat and lid are being closed, and FIG.  12 (C) shows a completely closed condition. 
     FIGS.  13 (A)-(C) illustrate the relationship between the opening angle of the toilet seat and lid and the damping force (buffering force) of the damping device used in the toilet seat/toilet lid unit of FIG. 1, where FIG.  13 (A) shows the torque curve for the non-circular shape of the inner circumferential surface of the casing, FIG.  13 (B) shows the torque curve due to the non-circular shape of the rotor core, and FIG.  13 (C) shows the torque curve due to the cavity in the cover end surface. 
     FIG. 14 is a cross sectional view along the circumferential direction of the cavity provided in the cover end surface of the damping device used in the toilet seat/toilet lid unit of FIG.  1 . 
     FIG. 15 is a cross sectional view showing an alternative cavity provided in the cover end surface of the damping device used in the toilet seat/toilet lid unit of FIG.  1 . 
     FIGS.  16 (A) and (B) show an alternative cover of the damping device, where FIG.  16 (A) is a plan view of an inside surface of the cover, and FIG.  16 (B) is a partial cross-sectional view along the line B—B of FIG.  16 (A). 
     FIG. 17 is a plan view of a toilet seat/toilet lid unit according a second embodiment of the present invention. 
     FIG. 18 is a side view of the toilet seat/toilet lid unit in FIG. 17 from the direction of the arrow A. 
     FIG. 19 is a perspective view of the toilet seat/toilet lid unit of FIG.  17 . 
     FIG. 20 is a top cross sectional view of a toilet seat/toilet lid unit according to a third embodiment of the present invention. 
     FIGS.  21 (A)-(C) are perspective views of alternative embodiments of the movable valve used in the damping device of FIG. 1, where FIG.  21 (A) is a first alternative embodiment in which the cut-out recess is not provided, FIG.  21 (B) is a second alternative embodiment, and C is a third alternative embodiment. 
     FIGS.  22 (A)-(D) show a support shaft that passes through the damping device used in the toilet seat/toilet lid unit of FIG. 1, where FIG.  22 (A) is a plan view, FIG.  22 (B) is a front view from the direction of the arrow B in FIG.  22 (A), FIG.  22 (C) is a cross-sectional view along the C—C cross section in FIG.  22 (A), and FIG.  22 (D) is a side view along the direction of the arrow D in FIG.  22 (A). 
     FIGS.  23 (A) and (B) show an alternative embodiment of the support shaft used in the toilet seat/toilet lid unit of FIG. 1, where FIG.  23 (A) is a plan view, and FIG.  23 (B) is a side view along the direction of the arrow B in FIG.  23 (A). 
     FIGS.  24 (A)-(C) show another alternative embodiment of the support shaft used in the toilet seat/toilet lid unit of FIG. 1, where FIG.  24 (A) is a plan view, FIG.  24 (B) is a side view along the direction of the arrow B in FIG.  24 (A), and FIG.  24 (C) is a side view along the direction of the arrow C in FIG.  24 (A). 
     FIGS.  25 (A) and (B) show the shape of the insertion holes, openings and holes when the support shaft of FIG. 26 is used, where FIG.  25 (A) shows the shape of the insertion holes and openings, and FIG.  25 (B) shows the shape of the holes. 
     FIG. 26 is an exploded perspective view of a conventional opening/closing device for toilet seats and toilet lids. 
     FIG. 27 is an exploded perspective view of another conventional opening/closing device for toilet seats and toilet lids. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention are described below with reference to FIGS. 1-25. As shown in FIG. 1, a western-style toilet includes a toilet body (not shown) and a toilet seat/toilet lid unit  1  attached to the toilet body. The toilet may also includes a tank (not shown) that holds the rinse water. 
     Referring to FIGS. 1 and 2, the toilet seat/toilet lid unit  1  includes a toilet seat  11 , a toilet lid  12 , two toilet seat hinges  13 ,  14  that serve as attachment hinges, two toilet lid hinges  15 ,  16  that serve as attachment hinges disposed outside the respective toilet seat hinges  13 ,  14 , a first damper  17  that is provided between one of the toilet seat hinges  13  and one of the toilet lid hinges  15 , a second damper  18  that is provided between the other of the toilet seat hinges  14  and the other of the toilet lid hinges  16 , a first support shaft  19  that is linked with the first damper  17 , and a second support shaft  20  that is linked with the second damper  18 . The first damper  17  includes a first attachment casing  21  and a first damping device  22 , and the second damper  18  includes a second attachment casing  23  and a second damping device  24 . The toilet lid  12  is disposed so that it lays on top of the toilet seat  11  when closed. 
     As shown in FIG. 1, the toilet seat hinges  13  is formed from a resin member so that it is integrated with the toilet seat  11 , and protrudes slightly from the body of the toilet seat  11  on the side of the tank. A hole  26  having an elongated cross-sectional shape is provided on the toilet seat hinge  13  so that it may be linked while being able to rotate as a unit with the support shaft  19 . The other toilet seat hinge  14  also is formed from a resin member integrated with the toilet seat  11 , and is formed so that its over-all shape is the same as that of the toilet seat hinge  13 . The toilet seat hinge  14  has a hole  27  with a circular cross-sectional shape so that it may be linked while allowing the support shaft  20  to rotate. 
     The toilet lid hinges  15  is formed from a resin member integrated with the toilet lid  12 , and is formed so that it is opposite the toilet seat hinge  13 . The toilet lid hinge  15  has a hole  28  with a circular cross section so that it may be linked while allowing the support shaft  19  to rotate. The other toilet lid hinge  16  is also formed from a resin member integrated with the toilet lid  12 , and is formed with the same shape as the toilet lid hinge  15 . A hole  29  having an elongated cross-sectional shape is formed in the toilet lid hinge  16  so that it may be linked while being able to rotate as a unit with the support shaft  20 . The cross-sectional shapes of the support shafts  19  and  20  are the same as the cross-sectional shapes of the holes  26  and  29 . 
     The second damper  18  and the first damper  17  are formed from the same material, have the same external shapes and the same structure. Thus, a description will be presented for the structure of the first damper  17  only. The same numerals are used for the second damper  18  in the figures. 
     The first attachment casing  21  of the first damper  17  has a fastening flange  31  for attachment to the toilet body, an attachment hole  32  provided in the fastening flange  31 , an insertion hole  33  in which a first damping device  22  is inserted (“damping device  22 ” is used for describing the structures for both of the damping devices  22  and  24  below), four cavities  34  in which the four screw fastening parts  41  of the damping device  22  are fit, and a flat alignment part  35  through which one alignment protrusion  42  of the damping device  22  may pass. 
     In addition to the positioning protrusion  42  and the four screw fastening parts  41 , the damping device  22 , as shown in FIGS. 1-5, also includes a casing  52  composed of resin having a hole  51  at its center, a cover or end portion  54  composed of resin that fits on the casing  52  and has a hole  53  in its center, a rotor  55  composed of resin that fits in the holes  51  and  53  and is sandwiched by the casing  52  and the cover  54 , and a silicone viscous oil  56  that fills the spaces enclosed by the casing  52 , the cover  54  and the rotor  55 . The casing member is constituted by the casing  52  and the cover  54 . 
     The damping device  22 , as shown in FIG. 4, has two movable valves  57  composed of resin that control movement of the viscous oil  56  an also constitute part of the rotor  55 , O-rings  59  composed of rubber material for sealing the viscous oil  56  which is inserted into grooves  58  provided in the rotor  55  as shown in FIG. 3, and an O-ring  60  composed of rubber material for sealing the liquid viscous oil  56 , which is sandwiched by the casing  52  and cover  54 . 
     The casing  52 , as shown in FIG. 5, has four protrusions  61  that constitute the screw fastening parts  41 , four cylindrical parts  62  that connect with each of the protrusions  61 , four screw holes  64  in which are inserted screws  63  for integrating the casing  52  and the cover  54 , two protrusions  65  that extend radially so that they protrude and prevent movement of the liquid that has been discharged towards the center by virtue of abutting a cylinder  81  of the rotor  55 , and oil space forming holes  66  for the purpose of providing a space for retaining the viscous oil  56 . 
     A small-diameter protrusion  67  that protrudes slightly outwards is provided outside the hole  51  in order to reduce the surface area of contact with the toilet seat hinge  13 , to link with the attachment casing  21 , and to effect positioning. In addition, a circular protrusion  52   a  for linking with the cover  54  is provided on the side of the cover  54 , and cylindrical protrusions  65   a  are provided on the tips of the protrusions  65  on the side of the cover  54 . In addition, the screw  63  is a self-tapping screw (i.e., the screw groove is formed by itself). Fastening of the casing  52  and the cover  54  may be carried out by fastening via ultrasonic welding, rather than with a screw. 
     The tips of the protrusions  65  on the side of the rotor  55  have a rounded tooth-like surface so that they may make contact with the core  81  of the rotor  55 . The circumferential width of the protrusions  65  is set to span an angle of 20 degrees. In addition, as shown in FIG. 5, the hole  66  for forming the oil space has large hole diameter regions  68  that form spaces with the movable valve  57  due to the large hole diameter φ 1 , and small hole diameter regions  69  that are in close contact with the movable valve  57  and constitute a diameter φ 2  smaller than that of the large hole diameter regions  68 . 
     Both the large hole diameter regions  68  and the small hole diameter regions  69  are disposed with a center of symmetry at the center of the axis of rotation of the rotor  55 . In addition, in this embodiment, the hole diameter φ 1  is 18 mm, and the range thereof is about 60 degrees. On the other hand, the hole diameter φ 2  is 12 mm, and the range thereof is about 75 degrees. Thus, the connecting regions  70  that connect the large hole diameter regions  68  and the small hole diameter regions  69  are straight lines, and have ranges of about 25 degrees. 
     The cover  54 , as shown in FIG. 6, has a hole  53 , as well as four protrusions  71  that constitute a screw fastening part  41 , four screw holes  71  a for fastening screws  63  to the protrusions  71 . In addition, as shown in FIG. 3, the cover  54  has a small diameter protrusion  72  that protrudes slightly outwards in order to decrease the surface area of contact with the toilet seat hinge  13  so that rotation with the toilet seat hinge  14  or toilet lid hinge  15  may occur smoothly. The cover  54  also has a circular groove  73  in which an O-ring  60  and the circular protrusion  52   a  of the casing  52  may be inserted, two circular cavities  74  in which cylindrical protrusions  65   a  fit, and two cavities  75  that gradually narrow in the direction of damping. Here, the direction of damping (“damping direction”) is the direction of rotation of the rotor  55  which gives an increased damping force (controlling force). 
     The cavities  75  are provided with point symmetry on the end surfaces in the axial direction on the inside of the cover  54 . In addition, each of the cavities  75  has a deep cavity  75   a  that is the deepest and is present at the end, a medium cavity  75   b  of medium depth, and a shallow cavity  75   c  that is the shallowest. The deep cavity  75   a  is the widest, and the shallow cavity  75   c  is the narrowest, with the width of the tip being zero. In this embodiment, the depth of the deep cavity  75   a  is 2 mm, the depth of the medium cavity  75   b  is 1.5 mm, and the depth of the shallow cavity  75   c  is 1.0 mm. In addition, the cavities are formed so that the length of each of the cavities  75  in the circumferential direction spans an angle of about 110 degrees. In addition, a gate (not shown) is provided in the center cavity  75   b  during resin molding, so that the gate does not protrude to the surface. 
     The rotor  55  has two movable valves  57  described below. In addition, as shown in FIGS. 7 and 8, the rotor  55  has grooves  58  in which O-rings  59  are inserted, a cylindrical core  81  against which the protrusions  65  of the casing  52  may contact while allowing it to move, two damping protrusions  82  to which the movable valves  57  are linked, the damping protrusions  82  being provided so that they protrude outwards from the core  81 , an insertion hole  83  that opens along the line of the center axis of the core  81  through which the support shaft  19  is inserted, and protruding contact portion  84  that are respectively contacted by the casing  52  and the cover  54 . 
     The respective damping protrusions  82  each have a groove  85  in which the arm  93  of the movable valve  57  is inserted as shown in FIGS.  9 (A) and (B), and a latching protrusion  86  that is inserted into the cut-out recess  94  of the movable valve  57 , and serves as a retaining part for preventing exit of the movable valve  57 . Each of the grooves  85  is formed by an outer large protrusion  82   a , an inner small protrusion  82   b  and a base  82   c  for the damping protrusion  82 . The latching protrusion  86  is integrated into the width in the circumferential direction of the large protrusion  82   a  so that it slightly protrudes laterally with respect to the surface of the inside of the tip of the large protrusion  82   a.    
     The core  81  of the rotor  55 , as shown in FIG. 8, is disposed with its center of symmetry at rotation axis of each of the rotors  55 , and is divided into regions of three different diameters: small-diameter regions  87 , medium-diameter regions  88 , and large-diameter regions  89 . The small-diameter regions  87  are the regions with the smallest diameter, and when the toilet seat  11  is open (in the raised condition), they are the regions that are opposite the protrusions  65 . At this time, as shown in FIG.  11 (C), a small gap G 4  is present between the protrusions  65  and the small-diameter regions  87 , and the viscous oil  56  may move through the gap G 4 . 
     The medium-diameter regions  88  are regions having a somewhat larger diameter than that of the small-diameter regions  87 , and are the regions that are opposite the protrusions  65  when the toilet seat  11  is somewhere between the open and closed positions. At this time, as shown in FIG.  11 (B), there is no gap between the protrusions  65  and the medium-diameter regions  88 , as by design, the inner diameters of the protrusions  65  are the same as the outer diameters of the medium-diameter regions  88 . The damping protrusion  82  of the rotor  55  is formed so that the protrusion  65  is opposite the medium-diameter region  88  approximately when movement occurs from the large hole diameter region  68  to the small hole diameter region  69  of the casing  52 . 
     The large-diameter regions  89  are regions with diameters that are slightly larger than the that of medium-diameter regions  88 , and are the regions that are opposite the protrusions  65  in the period from immediately prior to closing of the toilet seat  11  to complete closure. With the large-diameter regions  89 , as shown in FIG.  11 (A), the protrusions  65  dig into the large-diameter regions  89  and apply a large braking force to the rotor  55 . 
     In this embodiment, the diameter φ 3  of the small-diameter region  87  is 11.2 mm, the diameter φ 4  of the medium-diameter region  88  is 12 mm, and the diameter φ 5  of the large-diameter region  89  is 12.35 mm. In addition, the connection region  81   a  of the small-diameter region  87  and the medium-diameter region  88  and the connection region  81   b  of the medium-diameter region  88  and the large-diameter region  89  are both straight lines. In this manner, the outer circumference of the core  81  is non-circular in that it is formed of arcs and straight lines. An elliptical shape wherein the diameter gradually increases or some other non-circular shape may also be used. In this embodiment, the angle of the small-diameter region  87  is about 40 degrees, the angle of the medium-diameter region  88  is about 45 degrees, and the angle of the large-diameter region  89  is about 45 degrees, with the angle for each of the connection regions  81   a ,  81   b  being about 15 degrees. 
     The insertion hole  83  of the rotor  55  forms a passage hole through which the rotor  55  passes along the axis of rotation. In addition, the cross-sectional shape of the or insertion hole  83  is elongated with all of the four comers being circular curved lines. This shape is similar to the cross-sectional shape of the support shaft  19 . 
     The viscous oil  56  is used to provide a damping action, or a buffering action, for the damping device  22 . This action is manifested by applying a resistive force with respect to rotation of the rotor  55 . In this embodiment, silicone oil is employed as the viscous oil  56 , but other types of oil may also be used. 
     As shown in FIG. 11, the two movable valves  57  have the same shape, and are situated symmetrically about one point, with the axis of rotation of the rotor  55  as the center. The movable valve  57 , as shown in FIG.  9  and FIG. 10, includes an oil impingement part  91  with a triangular cross section, and two arms  93  having two hooks  92  at their respective tips that stop the exit of the movable valve  57  from the damping protrusion  82  due to the motion in the circumferential direction of the movable valve  57 . The arms  93  are equipped with cut-out recesses  94  in which the latching protrusion  86  (see FIG. 7) of the rotor  55  is inserted. 
     The oil impingement part  91  serves as a pressure part that is acted upon by the pressure of the viscous oil  56  which is a liquid. The front surface of the oil impingement part  91  constitutes the pressure surface  91   a , and when the viscous oil  56  impinges thereupon, the movable valve  57  becomes an inwardly-slanting surface so that compression force is produced on the side of the casing  52 . The pressure surface  91   a  in this embodiment is the surface that faces the center O of the rotor  55 , and is a surface that has an aperture of 17 degrees from the center line L 1  of the movable valve  57 . Moreover, the upper surface  57   a  of the movable valve  57  constitutes a curved surface having a radius of curvature of 9.5 mm, and is identical to the shape of the curved surfaces of the large hole diameter regions  68  of the casing  52 . 
     The movable valve  57  may move slightly back and forth in the circumferential direction with respect to the damping protrusion  82 . This shifting occurs due to the relative movement of the latching protrusion  86  in the cut-out recess  94 . When the rotor  55  moves in the direction indicated by the arrow C in FIG. 4 (the closing direction), the pressure surface  91   a  of the oil impingement part  91  of the movable valve  57  impinges upon the viscous oil  56 , and the back surface  91   b  of the oil damping part  91  impinges upon the damping protrusion  82 , so that movement towards the casing  52  occurs due to the upwards component force F 1  (FIG.  9 (B)) of the resistance force F of the viscous oil  58 . When this happens, the viscous oil  56  present in the direction of frontward rotation of the oil impingement part  91  does not have any space to retreat, and thus a force is generated that stops rotation of the rotor  55 . This constitutes a part of the damping force (buffering force, or controlling force). 
     On the one hand, when the rotor  55  rotates in the direction indicated by the arrow D in FIG. 4, in other words, when the toilet seat  11  is moved in the open direction, the back surface  91   b  of the oil impingement part  91  of the movable valve  57  is acted upon by a resistance force from the viscous oil  56 , and by this means, the reverse surface  91   b  of the oil impingement part  91  is separated from the damping protrusion  82 . As a result, the viscous oil  56  present in front of the rotational direction of the oil impingement part  91  passes through the gap formed between the reverse surface  91   b  of the oil impingement part  91  and the damping protrusion  82 , so that it moves in a direction opposite to the direction of rotation. As a result, little or no damping force is generated, and the toilet seat  11  may be moved towards the open direction with light force. 
     The damping device  22  is left-right symmetrical in terms of its external shape, with a line perpendicular to the center axis as the line of symmetry, excluding the positioning protrusion  42 . For this reason, by changing the position of the positioning flat surface  35 , the part may be used as the damping device  22  that has the reverse damping direction. 
     Support shafts  19  and  20  are made from the same member, and as shown in FIG. 22, have a long and thin shape. The cross-sectional shape of the support shafts  19  and  20  is elongated, with the four corners being circular curves. A beveled part  95  that is beveled around its entire circumference is provided at both ends of each of the support shafts  19  and  20 , and each of the ends has an elongated form with a diameter that is slightly smaller than the elongated cross-section. Both ends  96  of both support shafts  19  and  20  provide supports for the respective toilet seat hinge  13  and toilet lid hinge  15 , and in addition, provide supports for the toilet seat hinge  14  and toilet lid hinge  16 . 
     Specifically, as shown in FIGS. 1 and 2, support shafts  19  and  20  are inserted into the insertion holes  83  through which the rotors  55  pass in the axial direction. One end of the support shaft  19  is connected with the hole  26  of the toilet seat hinge  13  so that it may rotate as a unit therewith, and the other end is linked to a hole with a circular cross section of the toilet lid hinge  15  so that the support shaft may rotate along with the rotor  55 . On the other hand, one end of the support shaft  20  is linked with the hole  29  of the toilet lid hinge  16  so that it may rotate as a unit therewith, and the other end is linked to a hole  27  with a circular cross section in the toilet seat hinge  14  so that the support shaft may rotate along with the rotor  55 . By this arrangement, movement of the toilet seat  11  in the closing direction is damped by the first damping device  22 , and movement of the toilet lid  12  in the closing direction is damped by the second damping device  24 . 
     As described above, insertion holes through which the support shafts pass are provided, and the same toilet damping device may be used for the right and left sides. Insertion of the support shafts is thus possible, in spite of the fact that the direction in which the support shafts are inserted is different on the right and left sides. As a result, right and left toilet damping devices having the same shape may be used, even if there are requirements in terms of shape for the toilet. Because toilet seat damping devices that have the same shape may be used, error-free installation will be made easier. Moreover, the cost of the toilet damping device is reduced. 
     Various methods may be used to assemble the first and second dampers  17  and  18 . A preferred method is described here. First, as shown in FIG. 1, the two damping devices  22 ,  24  are assembled in the two attachment casings  21 ,  23 . Next, dampers  17  and  18  are inserted between the respective toilet seat hinge  13  and toilet lid hinge  15 , and the toilet seat hinge  14  and toilet lid hinge  16 , and the support shaft  19  is inserted in the direction of the arrow A in FIG.  2 . The support shaft  20  is then inserted in the direction indicated by arrow B in FIG.  2 . Assembly of the toilet seat/toilet lid unit  1  is thereby completed. Screws are then fed into the attachment holes  32  for dampers  17  and  18 , and the toilet seat/toilet lid unit  1  is attached to the toilet body by fastening with screws. 
     The operation of the toilet with attached toilet seat/toilet lid unit  1  and the rotational action of the toilet seat  11  and toilet lid  12  is described below with reference to the operation of the first and second damping devices  22 ,  24 . 
     The toilet seat  11  and toilet lid  12  are initially closed. When a user starts to rotate the toilet seat  11  and toilet lid  12  towards the tank, the rotors  55  of the two damping devices  22 ,  24  rotate in the direction of the arrow D in FIG.  11 (A). Specifically, the rotors  55  rotate from the position shown in FIG.  11 (A) towards the position indicated in FIGS.  11 (B) and  11 (C). 
     In addition, the gap G 2  between the inner circumferential surface of the casing  52  and the movable valve  57  gradually increases from zero. A gap G 3  is produced between the movable valve  57  and the base  62   c  of the damping protrusion  82 . For this reason, the viscous oil  56  that is present in the spaces H and J passes through the small protrusions  82   b ,  82   b , and escapes into spaces I and K from the gap G 1 . In addition, some of the liquid also passes through the gaps G 2 , G 3 . As a result, the viscous oil  56  in the spaces H and J is not under substantial pressure, and the resistance force is small. In other words, the viscous oil  56  is not blocked by the movable valve  57 , and almost no resistance force is applied. The toilet seat  11  and toilet lid  12  may thus be opened with a light force. 
     In addition, the core  81  of the rotor  55  and the protrusions  65  are initially in a compressed state as shown in FIG.  11 (A). Subsequently, as shown in FIG.  11 (B), they assume a condition of simple contact. Finally, a large gap G 4  is generated between them as shown in FIG.  11 (C). For this reason, rotation of the rotor  55  is initially slightly controlled, but a condition is soon produced wherein there is no regulation, and as described above, the toilet seat  11  and toilet lid  12  continue to be opened with light force. Subsequently, after rotating over about 100 degrees, the toilet lid and seat strike the tank and the rotation is stopped. Both of the damping devices  22  and  24  are constituted in such a manner that they may rotate over a range of about 120 degrees. This is because the angle in the circumferential direction of the protrusion  65  is 20 degrees, and the range in the circumferential direction of the movable valve  57  is about 40 degrees. 
     After using the toilet, when the toilet seat  11  and toilet lid  12  are rotated in the closing direction, both rotors  55  rotate in the direction indicated by the arrow C in FIG.  12 (A). Initially, the movable valve  57  experiences resistance of the viscous oil  56  in the spaces I and K, and as shown in FIG.  12 (A), moves in the opposite direction as that indicated by the arrow C, thus eliminating the gap G 1 . However, at this time, the movable valves  57  are opposite the large hole diameter regions  68  of the casing  52 , and a gap G 2  is formed with the movable valve  57 . In addition, the protrusions  65  and the small-diameter regions  87  are opposite each other, and gaps G 4  are produced between the two. As a result, the toilet seat  11  and toilet lid  12  move easily together. Due to the rotation of the regions in the C direction, the movable valve  56  experiences a component force F 1  in the direction of the casing  52 , and thus a gap G 3  is generated between the damping protrusion  82  and the base  82   c  as before. 
     Subsequently, the movable valves  57  that have been provided for each of the rotors  55  begin to move opposite the small hole diameter region  69  of the casing  52 , and the gap G 2  between the two narrows, so that viscous oil  56  in the spaces I and K is compressed, and the resistance force of the viscous oil  56  increases. A damping force (buffering force) thus begins to act on the toilet seat  11  and toilet lid  12 . Specifically, if the toilet seat  11  or toilet lid  12  is released from the user&#39;s hand at this stage, they will not free-fall to the closed position. At this time, the medium-diameter regions  88  of the rotors  55  contact the protrusions  65  as shown in FIG.  12 (B), and the gap G 4  is eliminated. 
     Subsequently, as the toilet seat  11  and toilet lid  12  are further rotated, and each of the rotors  55  move farther in the direction indicated by the arrow C, the movable valve  57  contacts the small hole diameter region  69  of the casing  52 , and the gap G 2  is completely eliminated, and the gap G 3  also goes to zero due to the compressive force. For this reason, the viscous oil  56  in the spaces I and K is strongly compressed, and the resistance force further increases. 
     Due to this rotation, the large-diameter regions  89  of the rotors  55  begin to engage the protrusions  65 , and a damping force is applied by the viscous oil  56 , a breaking force thereby begins to act in this region. By this means, a strong damping force is exerted, and the toilet seat  11  and toilet lid  12  fall slowly even when released from the user&#39;s hand so that they do not strike strongly against the toilet body  1 . For this reason, when the toilet seat  11  and toilet seat  12  are released from the hand while being closed, an impact sound will not be generated as with the conventional devices. 
     In transition from the position shown FIG.  12 (B) to that shown in FIG.  12 (C), when there are no escape locations, the viscous oil  56  in the spaces I and K moves in small amounts into the spaces H and J between small gaps such as the small gap between the movable valve  57  and the damping protrusion  82  of the rotor  55 , the small gaps at various locations between the rotor  55  and casing  52  and the small gap between the protrusion  65  and the core  81 . The resistance force at this time is large, and thus the toilet seat  11  and toilet lid  12  close slowly. They then close more rapidly as the resistance decreases. 
     The condition of the damping force in each region is shown in FIGS.  13 (A)-(C). The change in damping force is described with reference to FIGS.  13 (A)-(C) and FIGS.  12 (A)-(C). 
     The change in damping force due to the non-circular shape of the inner circumferential surface of the casing  52  is described first. As shown in FIG. 12A, in the open position (100 degrees), the movable valve  57  is opposite the large hole diameter region  68 , and a condition is produced in which a gap G 2  is present. For this reason, the damping force is zero, as shown in FIG.  13 (A). Subsequently, the rotor  55  is rotated in the direction of the arrow C in FIG.  12 (A), and the movable valve  57  begins to oppose the connecting region  70 . When the toilet seat  11  and lid  12  reach the position where they are 75 degrees open, the front end of the movable valve  57  begins to contact the connecting region  70 , and the damping force begins to act. When the rotor  55  rotates and additional 5 degrees, it begins to contact the small hole diameter region  69 . 
     When the opening angle of the outer circumference of the movable valve  57  reaches about 40 degrees, it begins to contact the small hole diameter region  69 , and from this point on, the surface contact area continues to increase gradually, and the damping force increases with a constant slope in conjunction therewith. Thus, when the opening angle of the toilet seat  11  and lid  12  reaches 30 degrees, the entire surface of the movable valve  57  contacts the small hole diameter region  69 , and consequently, a constant torque results. Because the inner circumferential surface of the casing  52  is non-circular, it is possible to obtain a torque curve whereby the damping force gradually increases. This torque curve resembles the curve for the angular moment during closing of the toilet seat  11  or toilet lid  12  when there are no damping members. Thus, when a damping force is applied by means of using a non-circular surface for the inner circumference of the casing  52 , the toilet seat  11  and toilet lid  12  close gradually at a nearly constant rate regardless of the angle, and no sound of impact is produced. 
     The damping force produced due to the non-circular shape of the core  81  of the rotor  55  is described next. The torque curve at this time is shown in FIG.  13 (B). The position when the toilet seat  11  or toilet lid  12  are open at an angle of 100 degrees is taken as the open position. This condition corresponds to the condition shown in FIG.  12 (A). When the toilet seat  11  and lid  12  are rotated and the rotor  55  rotates in the direction indicated by the arrow C, after a rotation of 10 degrees, the protrusion  65  begins to contact the medium-diameter region  88  of the rotor  55 . At this time, the gap between the medium-diameter region  88  of diameter φ 4  (FIG. 8) and the two protrusions  65  is constant, and thus almost no damping force is applied. However, as the surface area of abutment increases, the damping force continually increases in small amounts, and when the toilet seat  11  and lid  12  reach 70 degrees, the entire inner surface of the protrusion  65  is against the middle diameter region  88 , so that the frictional force is constant over the subsequent range of about 35 degrees, thus producing a constant damping force. 
     The protrusion  65  then contacts the straight connecting region  81   b , and the core  81  transitions to a compressed condition. As a result, the damping force continues to increase precipitously. The rotor  55  then rotates an additional 15 degrees, and when the opening angle of the toilet seat  11  and lid  12  become 30 degrees, the protrusion  65  begins to contact the large-diameter region  89 . The surface area of contact with the large-diameter region  89  then increases gradually, and thus the frictional force increases at a constant ratio. The curved surface of the protrusion  65  then entirely contacts the large-diameter region  89 , and the torque (the damping force) becomes constant. Because the core  81  of the rotor  55  is non-circular, a torque curve may be obtained wherein the damping force gradually increases. Thus, by making the core  81  of the rotor  5  non-circular, it is possible to obtain an opening torque curve that corresponds to the angular moment of the toilet seat  11  or toilet lid  12  for the damping force. 
     Next, the damping force torque curve due to the cavity  75  provided at the end surface of the cover  54  will be described with reference to FIG.  13 (C). When the toilet seat  1  is in the open position, the surface opposite the cavity  75  of the damping protrusion  82 , as shown by the dotted lines in FIG. 14, is oriented so that it extends over the deep cavity  75   a  and the medium cavity  75   b . For this reason, the viscous oil  56  in the spaces I and K passes through the cavities  75  and is transferred smoothly into the spaces H and J. As a result, as the opening angle of the toilet seat  11  and lid  12  move from 100 degrees to 90 degrees, the damping force is small, and the increase of the damping force is very slight. As the opening angle moves to 90 degrees, the damping protrusion  82  begins to move opposite the medium cavity  75 , and the damping force increases slightly; but since the viscous oil  56  still moves smoothly, the damping force is fairly small. 
     Subsequently, when the open angle reaches 80 degrees, the damping protrusion  82  begins to move opposite the shallow cavity  75   c , and the rate of increase in the damping force further increases. When the opening angle reaches 60 degrees, the damping protrusion  82  is completely opposite the shallow cavity  75   c , and the movement of the viscous oil  56  is fairly restricted, so that the rate of increase in damping force is further increased. When the opening angle is near 30 degrees, the resistance approaches infinity based on the action of this cavity  75  alone; but since the viscous oil  56  in the regions I and K flows into the cavity  75  from the other gaps, the torque does not become infinite. 
     At an opening angle of 30 degrees, the damping protrusion  82  begins to move away from the cavity  75  as shown by the dotted lines in FIG.  14 . At this time, the damping protrusion  82  and the end surface of the cover  54  are not completely in tight contact, and the viscous oil  56  in the spaces I and K may flow from the cavity  75  through the small gaps. This influx decreases as the damping protrusion  82  is further rotated. The damping force gradually increases. When the opening angle reaches 10 degrees, the damping protrusion  82  lies completely outside the cavity  75 , and subsequently, the torque becomes fairly constant. By means of this cavity  75 , a closing torque curve may be obtained that is in accordance with the angular moment of the toilet seat  11  or toilet lid  12 . 
     From the individual torque curves produced by combining the three damping forces described above, a closing torque curve may be obtained that corresponds to the angular moment of the toilet seat  11  and toilet lid  12 . By changing the non-circular shape of the casing  52 , the non-circular shape of the rotor  55 , the circular shape of the cavity  75  in the cover  54 , or the viscosity of the viscous oil  56 , it is easy to obtain closing torque curves that correspond to the rotational moments for various types of toilet seats  11  and toilet lids  12 . Moreover, the damping force for each of the torque curves shown in FIGS.  13 (A)-(C) are not shown in absolute values, in that each curve is a schematic curve used for purposes of illustrating torque trends. 
     When an user attempts to close only the toilet seat  11  after opening the toilet seat  11  and toilet lid  12 , the seat hinges  13  and  14  rotate, but the toilet seat hinge  14  may move freely with respect to the support shaft  20 . As a result, the second damping device  24  does not operate to damp the motion of the toilet seat  11 . On the other hand, the toilet seat hinge  13  is linked so that it may rotate as a unit with the support shaft  19 , so only the first damping device  22  generates damping force with respect to rotation towards the closed position of the toilet seat  11 . At this time, the action of the first damping device  22  is similar to the action of the first damping device  22  described above when the toilet seat  11  and toilet lid  12  are closed simultaneously. 
     When the toilet lid  12  is to be closed while the toilet seat  11  in a closed state, the toilet lid hinge  15  may now move freely with respect to the support shaft  19 , so the first damping device  22  does not generate a damping force for the toilet lid hinge  15 . The other toilet lid hinge  16  is linked so that it rotates as a unit with the support shaft  20 , so only the second damping device  24  generates a damping force with respect to rotation of the toilet lid  12  in the closing direction. The action of the second damping device  24  at this time is the same as the action of the second damping device  24  when the toilet seat  11  and toilet lid  12  are closed simultaneously. 
     The cross-sectional shape of the cavity  75  provided in the end surface of the cover  54 , as shown in FIG. 15, has a deepest region  75   e  and a sloped region  75   f  with decreasing depth. Thus, a device is produced that has even better rotation-stopping feel with respect to the angular moment of the toilet seat  11  and lid  12 . Moreover, as shown in FIGS.  16 (A) and (B), the cavity  75  may be such that the width in the radial direction narrows step-wise, while the depth of the cavity  75  is gradually reduced. As shown by the single dotted line of FIG.  16 (A), the width may be held constant while the depth is as shown in FIG.  16 (B); or the depth may be held constant while either the width is narrowed in steps as shown in FIG.  16 (A), or the width is gradually narrowed as shown in FIG.  6 . The structures shown in FIGS. 14-16 or the structure described above may be employed in a damping device according to other embodiments of the present invention. 
     The embodiment described above is a preferred embodiment of the present invention, but the invention is not restricted to this embodiment. Various changes may be implemented that are within the scope of the invention. For example, in the embodiment described above, the toilet seat hinges  13  and  14  are integrated with the toilet seat  11 , and the toilet lid hinges  15 ,  16  are integrated with the toilet lid  12 . However, as shown in FIGS. 17-19, a structure may be produced wherein the toilet seat  11  and the toilet seat hinges  163  and  164  are separate bodies, and the toilet lid  12  and the toilet lid hinges  165  and  166  are separate bodies, with the respective bodies being fastened with screws. In the FIGS.,  163 A,  164 A,  165 A and  166 A designate screw holes. 
     In FIGS. 17-19, the toilet seat/toilet lid unit  161  is attached to a toilet body  2  which includes a main body  5  and a tank  6 . Thus, the first damper  17  is installed between the toilet seat hinge  163  and the toilet lid hinge  165 , and the second damper  18  is installed between the toilet seat hinge  164  and the toilet lid hinge  166 . 
     In addition, in the embodiment described above, a structure may be produced wherein the attachment casing  21  and the casing  52  of the first damping device  22  are integrated, and the attachment casing  23  and the casing  52  of the second damping device  24  are integrated. 
     Moreover, the damping devices  22  and  24  need not be provided between the two hinges, as they may be provided on the insides of the two hinges (FIG.  20 ), or on the outside of the two hinges. With the toilet seat/toilet lid unit  171  of FIG. 20, the hinges  13  and  14  of the toilet seat  11  are disposed such that they are respectively sandwiched between the hinges  15  and  16  of the toilet lid  12  and both of the dampers  17  and  18 . In addition, respective gaps g are provided between the hinges  13  and  15  and hinges  14  and  16  so that when the toilet seat  11  is moved in the closing direction, the action does not affect the toilet lid  12 . In FIG. 20, a structure is shown wherein damping devices  22  and  24  are used. In order to facilitate understanding, horizontal lines are drawn to the parts whereby the rotor  55  of the support shafts  19  and  20  and the toilet seat hinge  13  and the toilet lid hinge  16  are linked so that they may rotate as a unit. This joining means that allows for integrated rotation may be an assembly having the type of elongated cross-sectional shape, or an assembly of a fitting hole and a support shaft that has a non-circular cross section, such as a serration joint. 
     In addition, as shown in FIG.  21 (A), the shape of the movable valves  57  and  116  need not include a cut-out recess  94 , and the rotors  55  and  115  need not have a latching protrusion  86 . Moreover, a structure may be formed wherein an arm  97  that connects with the arms  93  is provided, as shown in FIG.  21 (B), or wherein a horizontal arm  99  is provided and extends sideways from the arm  98 , as shown in FIG.  21 (C). A cut-out recess may also be provided in the arm of the movable valve of FIGS.  21 (B) and (C). 
     In addition, by providing only the first damper  17 , damping force may be applied only to the toilet seat  11 ; and by providing only the second damper  18 , damping force may be provided only to the toilet lid  12 . Moreover, a toilet lid  12  need not be provided. When a toilet lid  12  is not provided, three types of configurations may be employed: a structure where a damper is provided only on one of the toilet seat hinges of the toilet seat  11 ; a structure where dampers are provided on the toilet seat hinges of both sides in a symmetrical configuration; and a structure where the gap between the two toilet seat hinges is narrowed, and one toilet damping device is provided within the gap, with both ends or one end of the support shaft effecting the damping action. 
     In addition, screw holes through which screws  63  are inserted may also be provided in the protrusions  65 . The surface of the cover  54  may be provided with a small circular depression for thickness reduction in order to increase strength and reduce weight. Moreover, the constitution of the oil impingement part  91  of the movable valve  57  is not limited to the embodiment described above. In particular, the slant angle of the pressure-receiving surface  91   a  may be increased or decreased. 
     In addition, as shown in FIGS.  23 (A) and (B), the support shaft may have a square cross-sectional shape, and a support shaft  141  may be produced where the four comers  142  are highly beveled into curves. Alternately, as shown in FIGS.  24 (A)-(C), a support shaft  145  may be produced that includes a round cylinder  146  with a circular cross section, and a flat part  147  with an elliptical cross-section. 
     When the support shaft  141  is used, the hole  26  of the toilet seat hinge  13 , the hole  42  of the toilet lid hinge  16 , and the insertion holes  83  of the first and second damping devices  17  and  18  for the toilet may each have the same cross-sectional shape as the support shaft  141 , so that the support shaft  141  may be inserted and joined with each of them. On the other hand, the hole  36  of the collar  37  and the hole  29  of the collar  30  may have a circular cross-section so that the toilet seat hinge  14  and the toilet lid hinge  15  may rotate freely with respect to the support shaft  141 . 
     When the support shaft  145  is used, the hole  26  of the toilet seat hinge  13 , the hole  42  of the toilet lid hinge  16 , and the insertion holes  83  of the first and second toilet damping devices  17  and  18  may all have the special hole shape  148  shown in FIG.  25 (A) whereby the cylindrical part  146  and the flat part  147  are both inserted. On the other hand, the hole  29  of the collar  30 , and the hole  36  of the collar  37  may both have the circular cross-sectional shape  149  shown in FIG. 25B so that the toilet seat hinge  14  and the toilet lid hinge  15  may freely rotate with respect to the cylindrical part  146  of the support shaft  145 . 
     In addition, the above embodiments describe a damping device having two members that rotate relative to each other, where the outer member (the casing) is mounted to the toilet and stationary, while the inner member (the rotor) is linked to the rotating part of the toilet (the seat or the lid). Alternatively, the damping device may be constructed so that the inner member is mounted on the toilet and stationary, while the outer member is linked to the rotating part of the toilet (the seat or the lid). 
     Moreover, the damping devices  22  and  24  may be used for controlling the movement of other rotating members beside toilet seats and lids, such as for opening and closing lid members on electronic devices or the like. 
     It will be apparent to those skilled in the art that various modifications and variations may be made in a method of fabricating a thin film transistor of the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and equivalents.