2. Description of the Background Art As shown in Figure 1, a conventional toilet seat includes a toilet bowl 1 formed of a ceramic ware and opened in an upper side of the same, a toilet seat 2 which is hinged to an upper surface of'the toilet bowl 1 for thereby covering an upper surface of the same, a cover 3 which is hinged to an upper side of the toilet seat 2 for covering the toilet bowl 1, and a water tank 5 which is adapted to store

water in the toilet bowl 1 when a lever 4 is pushed.

The toilet bowl is generally used for feces and urine in a rest room in which a urinal is not separately installed in home. When a man passes urine, in order to prevent urine from being passed to a toilet seat 2, the toilet seat 2 is lifted up in the direction of the water tank 5.

At this time, since there is not any device for lifting up the toilet seat 2, when a man passes urine, the man must instantly lift up the toilet seat 2 positioned at the height of his knee using a hand in a posture that his waist is bent for thereby causing a certain inconvenience. In particular, it is very difficult for children or weak persons or waist patient to lift up the toilet seat 2 for use.

In addition, in order to lift up the toilet seat 2, the user may directly contact the toilet bowl 1 and the toilet seat 2 contaminated with urine, foreign substance, etc. for thereby causing a sanitation problem. In addition, in a posture that the user bends his waist, the use may directly see the interior of the toilet bowl 1 for thereby causing a bad visible problem.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an automatic opening apparatus of a toilet seat in which a toilet seat is rotated and is

automatically lifted up in a direction of a water tank when a user stands up from a toilet seat after use for thereby preventing a problem that a user bends his waist and manually lifts up a toilet seat.

It is another object of the present invention to provide an automatic opening apparatus of a toilet seat in which children or patients may use a toilet based on a good sanitation without an operation that a user directly contacts a toilet bowl body and toilet seat for lifting up a toilet seat.

In order to achieve the above objects, there is provided an automatic opening apparatus of a toilet seat which includes an elliptical plate shaped toilet seat which is adapted to cover an upper surface of a rim of a toilet bowl and rotatable in an upward and downward direction and hinged to a rear side of a rim of the toilet bowl, a rotation member which includes a driven portion integral to the toilet seat in a lower surface of a rear side of the toilet seat and is forwardly extended along a lower surface of the toilet seat from a rear end of the toilet seat, a rotation shaft portion which is extended in a lateral direction of the toilet seat from a rear end of the driven portion, and a driving potion which is backwardly extended from a front end of the rotation shaft portion and which is rotatable about the rotation shaft portion as a rotation shaft, a chain which is engaged to the driving portion of the rotation member at a certain distance from the rotation shaft

of the rotation shaft portion, and a foot rest unit which includes a support placed on a bottom and a stepping plate in which a front end of the same is fixedly hinged to the support, and the rear end of the same is fixed to a lower end of the chain and maintains a lifted state.

In a preferred embodiment of the present invention, the rotation member includes a driven portion which is fixedly inserted into a fixing groove formed in a rim of both sides of a rear end of the toilet seat and extended in both directions along a lower surface of the toilet seat from a rear center portion of the toilet seat, a rotation shaft portion which is extended from the driven portion to the rear side of the toilet seat and horizontally extended in both directions of the toilet seat, and a driving portion which includes left and right driving portions backwardly extended from both ends of the rotation shaft portion, wherein the rotation member is plastic- formed of a rod.

The rotation member is formed of a synthetic resin which is formed integrally with the toilet seat and includes a driven portion which is extended in parallel in a forward direction from both sides of the rim of a rear side of the toilet seat, a rotation shaft portion which is horizontally extended from the rear end of the driven portion to the left and right sides of the toilet seat, and a driving portion which is backwardly extended from a front end of the rotation shaft portion.

There is further provided a weight which is engaged to an end portion of the driving portion of the rotation member for thereby applying a certain stepping force of the stepping plate.

In order to achieve the above objects, there is provided an automatic opening apparatus of a toilet seat which includes an elliptical plate shaped toilet seat which is adapted to cover an upper surface of a rim of a toilet bowl and rotatable in an upward and downward direction and hinged to a rear side of a rim of the toilet bowl, a rotation member which includes a driven portion integral to the toilet seat in a lower surface of a rear side of the toilet seat and is forwardly extended along a lower surface of the toilet seat from a rear end of the toilet seat, a rotation shaft portion which is extended in a lateral direction of the toilet seat from a rear end of the driven portion, and a driving potion which is backwardly extended from a front end of the rotation shaft portion and which is rotatable about the rotation shaft portion as a rotation shaft, a fixing member which is fixed to the toilet bowl from a rear side of the toilet seat, and a pressing unit which is movable in an upward and downward direction of the fixing member and is lowered by an external force applied to its upper portion for thereby rotating the rotation member by pressing the driving portion of the rotation member, whereby the toilet seat is lifted up by an external force applied to the pressing unit.

In a preferred embodiment of the present invention, the rotation member includes a driven portion which is fixedly inserted into a fixing groove formed in a rim of both sides of a rear end of the toilet seat and extended in both directions along a lower surface of the toilet seat from a rear center portion of the toilet seat, a rotation shaft portion which is extended from the driven portion to the rear side of the toilet seat and horizontally extended in both directions of the toilet seat, and a driving portion which includes left and right driving portions backwardly extended from both ends of the rotation shaft portion, wherein the rotation member is plastic- formed of a rod.

The rotation member is formed of a synthetic resin which is formed integrally with the toilet seat and includes a driven portion which is extended in parallel in a forward direction from both sides of the rim of a rear side of the toilet seat, a rotation shaft portion which is horizontally extended from the rear end of the driven portion to the left and right sides of the toilet seat, and a driving portion which is backwardly extended from a front end of the rotation shaft portion.

The pressing unit is installed movably in an upward and downward direction by a guide of a guide rod vertically fixed to the fixing member and includes a pressing rod which is elastically supported by the compression spring with respect to the fixing member.

There is further provided a weight which is engaged to an end of the driving portion of the rotation member and is adapted to apply a weight based on the weight itself to the rotation member.

In order to achieve the above objects, there is provided an automatic opening apparatus of a toilet seat which includes an elliptical toilet seat which is rotatable in an upward and downward direction and is integral to a hinge shaft fixedly hinged to a rear side of an upper surface of a toilet bowl and has an opened center portion for thereby covering a rim of an upper surface of the toilet bowl, a weight which is installed in an extended plate which is extended from at least one side of the hinge shaft and maintains an initial state that the toilet seat is lifted from the toilet bowl, and a delay unit which is installed in one side of a lower surface of the toilet seat and prevents the toilet seat from being instantly lifted from the toilet bowl by the weight itself of the weight when a user stands up from the toilet seat after use.

In a preferred embodiment of the present invention, a plurality of assistant weights are detachably engaged to the weight for thereby adjusting the weight of the weights.

The delay unit includes an air absorption plate in which at least one absorption portion is detachably installed in an upper surface of the toilet bowl and

in a lower surface of the toilet seat, respectively, and an air amount adjusting member in which an air discharging groove is formed in a helical shape in a threaded portion engaged to a threaded hole formed in a fixing portion of the air absorption plate, for thereby adjusting time required for lifting the toilet seat from the toilet bowl by adjusting the amount of air discharge from the interior of the absorption portion.

The air absorption plate includes more than at least one air discharging hole formed in the absorption portion, and a cover which is selectively engaged to the air discharging hole for covering the air discharging holes.

In order to achieve the above objects, there is provided an automatic opening apparatus of a toilet seat which includes an elliptical toilet seat which is rotatable in an upward and downward direction and is integral to a hinge shaft fixedly hinged to a rear side of an upper surface of a toilet bowl and has an opened center portion for thereby covering a rim of an upper surface of the toilet bowl, an elastic member which is engaged to an outer side of the hinge shaft and includes one end fixed to a lower surface of the toilet seat, and the other end is fixed to a protrusion extended from a support plate by which a hinge shaft is rotatably fixed to an upper surface of the toilet bowl for thereby elastically biasing an initial state that the toilet seat is lifted up from the toilet bowl, and a delay unit

which is installed in one side of a lower surface of the toilet seat and prevents the toilet seat from being instantly lifted from the toilet bowl by a recovering force of the elastic member when a user stands up from the toilet seat after use.

The delay unit includes a protrusion plate which is protruded opposite to the lower surface of the toilet seat and has a concave semicircular groove in an opposite surface, and an engaging plate which is elastically supported by the protrusion extended in the support plate by which the hinge shaft is rotatably fixed to the upper surface of the toilet bowl for thereby being detachably engaged to the concave groove, wherein the time required for lifting the toilet seat from the toilet bowl is delayed based on a release of the locking force of the engaging plate with respect to the concave groove by an elastic member which is installed in the protrusion and has an elastic force smaller than the weight of the weight when a user stands up from the toilet seat after use.

The elastic member is formed of a pair of compression coil springs in which one end of each of the same is fixed to a lower surface of the toilet seat, and the other end of each of the same is fixed to an upper surface of the protrusion extended in the support plate that the hinge shaft is rotatably fixed to an upper surface of the toilet bowl.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become better understood with reference to the accompanying drawings which are given only by way of illustration and thus are not limitative of the present invention, wherein; Figure 1 is a perspective view illustrating a conventional toilet bowl ; Figure 2 is a perspective view illustrating an automatic opening apparatus of a toilet seat according to a first embodiment of the present invention; Figure 3 is a view illustrating a state of use of an opening apparatus of Figure 2; Figure 4 is a perspective view illustrating an automatic opening apparatus of a toilet seat according to a second embodiment of the present invention; Figure 5 is a view illustrating a state of use of an opening apparatus of Figure 4; Figure 6 is a perspective view illustrating an automatic opening apparatus of a toilet seat according to a third embodiment of the present invention; Figure 7 is a view illustrating a state of use of an opening apparatus of Figure 6; Figures 8A and 8B are views illustrating an operation principle of a pressing unit of Figure 6;

Figure 9 is a perspective view illustrating an automatic opening apparatus of a toilet seat according to a fourth embodiment of the present invention; Figure 10 is a perspective view illustrating an automatic opening apparatus of a toilet seat according to a fifth embodiment of the present invention; Figure 11 is a view illustrating a state of use of an opening apparatus of Figure 10; Figure 12 is a perspective view illustrating an automatic opening apparatus of a toilet seat according to a sixth embodiment of the present invention; Figure 13 is a view illustrating a state of use of an opening apparatus of Figure 12; Figure 14 is a perspective view illustrating an automatic opening apparatus of a toilet seat according to a seventh embodiment of the present invention; Figure 15 is a perspective view illustrating an automatic opening apparatus of a toilet seat according to an eighth embodiment of the present invention; and Figure 16 is a view illustrating a state of use of an opening apparatus of Figure 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of an automatic opening apparatus of a

toilet seat according to a first embodiment of the present invention will be described with reference to Figures 2 and 3.

As shown therein, in an automatic opening apparatus of a toilet seat according to the present invention, there are provided a ceramic toilet bowl 1, a cover 3 adapted for covering the upper side of the toilet bowl 1, and a water tank 5.

In the above toilet bowl, the toilet seat 2 is lifted up from an upper surface 1a of the rim portions of the toilet bowl 1. There are provided a toilet seat 1 in which a center portion is opened and has a certain shape, a rotation member 10 which is hinged to a rear side of the toilet seat 2, a chain 11 fixed to a rear end of the rotation member 10, and a foot rest member 14 fixed to a lower portion of the chain 11.

At this time, the toilet seat 2 is formed of an elliptical synthetic resin and is installed in such a manner that a user's skin does not contact with a rim upper surface 1 a by covering the rim upper surface 1 a of the toilet bowl 1 for a sanitation.

In a state that the toilet seat 2 is placed on the rim upper surface 1a of the toilet bowl 1, the rear end of the same is hinged to an upper rear side of the toilet bowl 1 in order for the toilet seat 2 to be lifted up.

In a state that the toilet seat 2 is placed on the upper surface 1a of the toilet bowl 1, the toilet seat 2 is capable of preventing the user's skin from being directly contacted with the toilet bowl 1. If necessary, the toilet seat 2 is lifted up

and is leaned against the water tank 5 as shown in Figure 3.

The rotation member 10 is plastic-formed and is formed of a rod closely contacting with a lower rear side of the toilet seat 2 and includes a circular driven portion 10a, a rotation shaft portion 10b extended backwardly from a rear center portion of the driven portion 10a in the right and left directions, and a left and right driving portion 10c which is backwardly extended from both ends of the rotation shaft portion 10b. A weight 10d having a certain weight is engaged to each end of the driving portion 10c.

The rotation member 10 is fixed in such a manner that both sides of the rotation shaft portion 10b are inserted into a fixing groove 2a formed in a rear rim portion of the toilet seat 2 in a state that the driven portion 10a closely contacts with a rear back surface of the toilet seat 2. The rotation member is fixed to a rear back surface of the same and is covered by the cover 15 attached to a lower surface of the toilet seat 2.

The rotation member 10 is rotated about the rotation shaft portion 10b by a force applied to the driving portion 10c, so that the toilet seat 2 is lifted up by the driven portion 10a.

At this time, the weight 10d engaged to an end portion of the driving portion 10c of the rotation member 10 is adapted to easily lift up the toilet seat 2 by

applying a certain moment to the driven portion 10a based on the weight when the toilet seat 2 is lifted up. In a state that the toilet seat 2 is lifted up at a certain angle, the toilet seat 2 is rotated by itself by the weight itself of the weight 10d and is rotated with respect to the water tank 5. In a leaned state, it is rotated in a reverse direction.

The chain 11 is formed of a flexible member which is suspended in the driving portion 10c of the rotation member 10 and has a lower side fixed to a stepping plate 13 of the foot rest unit 14, and a force applied to the stepping plate 13 is transferred to the driving portion 10c of the rotation member 10, so that the rotation member 10 is rotated in cooperation with the stepping plate 13.

At this time, the length of the chain 11 is determined to be tight in a state that the toilet seat 2 is placed on the upper surface 1 a of the toilet bowl 2, and the driving portion 10c of the rotation member is upwardly moved, and the stepping plate 13 is lifted up.

The foot rest unit 14 is formed of a support 12 formed of two plates hinged to each other and placed on the bottom of a rest room, and a stepping plate 13 hinged to a front portion of the support 12 for thereby being rotatable in the upward and downward directions.

At this time, a slide prevention protrusion 12a or a friction member (not

shown) may be attached to the bottom of the support 12 for thereby preventing a sliding. A lower portion of the chain 11 fixed to the driving portion 10c of the rotation member 10 is fixed to a rear end of the stepping plate 13.

When the user steps onto the stepping plate 13 of the foot rest unit 14, the stepping plate 13 is downwardly moved for thereby generating a stepping force in the vertical direction, so that the thusly generate force is transferred to the chain 11.

The operations of the automatic opening apparatus of a toilet seat according to a first embodiment of the present invention will be described with reference to Figures 2 and 3.

In the toilet bowl which is used for feces and urine, in the case that a man passes urine, it is possible to simply lift up the toilet seat from the toilet bowl in the following manner in order for the urine to not spread to the toilet seat.

Namely, shown in Figure 2, when the user steps onto the stepping plate 13 of the foot rest unit 14, the stepping plate 13 generates a certain force, and the thusly generated force is transferred to the driving unit 10c of the rotation member 10 through the chain 11. The rotation member 10 is rotated in the clockwise direction with respect to the rotation shaft portion 10b and converts the force into a torque. The thusly converted torque is applied to the lower surface of the toilet seat 2 through the driven portion 10a for thereby lifting up the toilet seat 2.

Therefore, it is possible to easily lift the toilet seat 2 using foot.

Therefore, in the automatic opening apparatus of a toilet seat according to the present invention, it is possible to overcome the problems that the toilet seat 2 is frequently lifted up from the toilet bowl 1 for use in the toilet system adapted for feces and urine.

Second embodiment As shown in Figures 4 and 5, the automatic opening apparatus of a toilet seat according to the present invention includes an elliptical plate shaped toilet seat 2 which covers an upper portion of a rim of a toilet bowl 1, a rotation member 20 which is engaged to a rear side of the toilet seat 2, a chain 11 which has an upper portion fixed to a driving portion 20c of the rotation member 20, and a foot rest unit 14 which is fixed to a lower portion of the chain 11. In particular, the rotation member 20 is integral with the toilet seat 2.

The rotation member 20 is formed of a synthetic resin like the toilet seat 2 and includes a driven portion 20a which is extended in parallel in the forward direction from both sides of the rim of the rear side of the toilet seat 2, a rotation shaft portion 20b which is horizontally extended in the left and right directions of the toilet seat 2 from the rear side of the driven portion 20a, a driving portion 20c

which is extended in the backward direction from the front end of the rotation shaft portion 20b, and a weight 20d engaged to a front end of the driving portion 20c.

Namely, in the automatic opening apparatus of a toilet bowl according to a second embodiment of the present invention, when comparing with the automatic opening apparatus of a toilet bowl according to a first embodiment of the present invention, there is a difference in their structures of the rotation member formed in the toilet seat 2. Namely, the other remaining elements and their operations are same. Therefore, the detailed description thereof will be omitted.

In the automatic opening apparatus of a toilet seat according to a second embodiment of the present invention, since the rotation member 20 is integral with the toilet seat 2 for thereby simplifying the construction. Therefore, it is possible to decrease the number of parts and the fabrication cost based on a decreased work process.

Third embodiment As shown in Figures 6 through 8, in the automatic opening apparatus of a toilet seat according to a third embodiment of the present invention, the toilet system includes a ceramic toilet bowl 1, a cover 4 which covers the upper portions of the toilet bowl 1, and a water tank 5. The automatic opening apparatus of a

toilet seat is directed to lifting up the toilet seat 2 which covers the upper portion 1a of the rim of the toilet bowl 1 for a sanitation. There are provided an elliptical plate shaped toilet seat 2, a rotation member 10 engaged to a rear side of the toilet seat 2, a fixing member 51 which is fixed to the toilet system together with the toilet seat 2, and a pressing rod 53 which is movable in the upward and downward directions with respect to the fixing member 51.

The toilet seat 2 is formed of an elliptical plate shaped synthetic resin and covers an upper portion 1 a of the rim of the toilet bowl 1 for a sanitation for thereby preventing the skin from being directly contacting with the upper surface 1a of the rim. The rear side of the same is hinged to the rear side of the upper surface of the toilet bowl rotatably in the upward and downward directions in such a manner that the toilet seat 2 is placed on the upper surface 1a of the rim of the toilet bowl 1 and is lifted up.

The toilet seat 2 is placed on the upper surface 1a of the rim of the toilet bowl 1 and prevents the user's skin from being directly contacted with the toilet bowl 1. If necessary, the toilet seat 2 is lifted up and is leaned against the water tank 5 as shown in Figure 7.

The rotation member 10 is a rod which is plastic-formed and is fixedly closed to the lower rear side of the toilet seat 2 and includes a circular driven

portion 10a, a rotation shaft portion 10b which is backwardly extended from the center of the rear end of the driven portion 10a and is extended in the left and right directions, and a left and right driving potions 10c which is backwardly extended from both sides of the rotation shaft portion 10b. A weight 10d having a certain weight is engaged to each end of the driving portion 10c.

In a state that the driven portion 10a is closely contacted with a bottom of the rear side of the toilet seat 2, the rotation member 10 is fixed to a bottom of the rear side of the toilet seat 2 in such a manner that both sides of the rotation shaft portion 10b are fixedly inserted into the fixing groove formed in the rim of the back side of the toilet seat 2 and is covered by the cover 55 attached to the back surface of the toilet seat 2.

The rotation member 10 is rotated about the rotation shaft portion 1 Ob by a force applied to the driving portion 10c for thereby lifting up the toilet seat 2 by the driven portion 10a.

The weight 10d engaged to an end portion of the driving portion 10c of the rotation member 10 applies a moment to the driven portion 10a based on its weight when the toilet seat 2 is lifted up, so that the toilet seat 2 is more easily lifted up.

In a state that the toilet seat 2 is lifted up at a certain angle, the toilet seat

2 is rotated by the weight of the weight 10d, and in a state that the toilet seat 2 is leaned against the water tank 5, the same is not rotated in the reverse direction.

The fixing member 51 is fixed to a rear side of the toilet bowl 1 by the fixing portion 51 b of one side end engaged to the toilet bowl 1 together with the toilet seat 2 and supports a guide rod 5 which is vertically installed on the surface.

The pressing rod 53 is a rod which is movable in the upward and downward directions and is inserted into the guide rod 52 fixed to the fixing member 51. The pressing rod 53 is installed in such a manner that the pressing rod 53 passes through the through hole 51 a formed in the fixing member 51 and is downwardly movable in a state that the roller 55 contacts with the driving portion 10c of the rotation member 10.

A handle 53a is engaged to the upper portion of the pressing rod 53. A guide pin 53b is installed in the intermediate portion of the same and is inserted into a slot 52a of the guide rod 52 for thereby guiding the upward and downward movements, so that it is possible to limit the moving distance. A compression spring 54 which is pressurized by the guide pin 53b is inserted into the lower portion of the same.

The pressing rod 53 is lowered from the state of Figure 8A to the state of Figure 8B by a pressure applied to the handle 53a of the upper end and presses

the driving portion 1 Oc of the rotation member 10 based on the roller 55 for thereby rotating the rotation member 10. When the pressure applied to the handle 53a is released, the pressing rod 53 is lifted and is returned to its initial position by a recovering force of the compression spring 54 compressed by the guide pin 53b.

The operation of the automatic opening apparatus of a toilet seat according to a third embodiment of the present invention will be described with reference to the accompanying drawings.

In the toilet system which is used for feces and urine, in particular, when a man passes urine in a standing posture, when the user presses the handle 53a of the pressing rod 53, the pressing rod 53 is lowered and presses the driving portion 10c of the rotation member 10. The rotation member 10 is rotated with respect to the rotation shaft portion 10b and converts the vertical weight into a torque. The thusly converted torque is applied to the bottom of the toilet seat 2 through the driven portion 10a for thereby lifting up the toilet seat 2. The toilet seat 2 is lifted up and is leaned against the water tank 5.

The toilet seat 2 stands by pressing the handle 53a of the pressing rod 53.

Since the handle 53a is positioned at a certain height higher than the upper surface 1a of the toilet bowl 1, the user is not needed to bend his waist. Therefore, it is possible to easily lift up the toilet seat 2 without touching the toilet bowl 1.

Therefore, it is possible to prevent the problems that the toilet seat 2 is frequently lifted up and lowered for using the same.

Fourth embodiment As shown in Figure 9, the automatic opening apparatus of a toilet seat according to the present invention includes an elliptical plate shaped toilet seat 2, and a rotation member 60 which is engaged to a rear side of the toilet seat 2. The rotation member 60 is integral with the toilet seat 2.

The rotation member 60 is formed of a synthetic resin like the toilet seat 2 and includes a driven portion 60a which is extended from both sides of the rim of the rear side of the toilet seat 2 in parallel in the forward direction, a rotation shaft portion 60b which is horizontally extended in the left and right directions of the toilet seat 2 from the rear side of the driven portion 60a, a driving potion 60c which is backwardly extended from the front end of the rotation shaft portion 60b, and a weight 60d engaged to a front end of the driving potion 60c.

In the automatic opening apparatus of a toilet seat according to a fourth embodiment of the present invention, when comparing with the automatic opening apparatus of a toilet seat according to a third embodiment of the present invention, there is a difference in their structures of the rotation member 60 fixed to the toilet

seat 2. The other remaining elements and their operations are same. Therefore, the detailed descriptions of the same will be omitted.

Fifth embodiment The fifth embodiments of the present invention will be described with reference to Figures 10 and 11.

The automatic opening apparatus of a toilet seat according to the present invention includes a ceramic toilet bowl 1 which has an opened upper side, a cover 3 which is operatively fixed to the rear side of the toilet bowl for thereby covering the upper surface of the toilet bowl 1, and a water tank 5 which stores water for supplying to the toilet bowl 1 by pressing the lever 4. The above construction is the same as the construction of Figure 1. Therefore, the construction and operation of the same will be omitted.

Therefore, as shown in Figures 10 and 11, the automatic opening apparatus of a toilet seat according to a fifth embodiment of the present invention includes: a toilet seat 2 which is integrally fixed to and is rotatably in an upward and downward direction to a hinge shaft 72 rotatably hinged by a pair of support plates 70 and 71 fixed to a rear side of an upper surface of a toilet bowl 1 and which is

formed of a synthetic resin in an elliptical shape having an opened center for thereby covering an upper surface of a rim of the toilet bowl 1; a weight 75 which is installed in a rod shaped extended plate 73 extended from at least one side of the hinge shaft 72 and is formed of a plurality of assistant weights 74 for adjusting the weight itself in such a manner that an initial state that the toilet seat 2 is lifted up from the toilet bowl 1 is maintained, and the speed that the toilet seat 2 is lifted to its initial position is adjusted based on an environmental factor of the toilet bowl such as a user's age, sex, heath state and installation place of the toilet bowl 1; and a delay unit which is installed in a lower one side of the toilet seat 2 and is detachable from an upper surface of the toilet bowl 1 and is capable of preventing any interference when the user ends the use of toilet in such a manner that the toilet seat 2 is automatically lifted up from the toilet bowl 1 based on a rotation of the weight 75 when the user stands up from the toilet bowl 1.

At this time, the delay unit includes an air absorption plate 77 in which at least one absorption portion 76 is installed in a lower surface of the toilet seat 2 detachably to an upper surface of the toilet bowl 1, an air discharging groove 80a which is formed in a threaded portion 80 in a helical shape engaged to a threaded hole 79 formed in a fixing portion 78 of the air absorption plate 77 for thereby

adjusting the amount of air discharge from the interior of the absorption portion 76.

The air absorption plate 77 is detachably engaged to an engaging groove 84 formed in a lower surface of the toilet seat 2 for a substitution when an absorption force is decreased due to a repeated use and may further include at least one air discharge hole 82 which is formed in the absorption portion 76 for thereby adjusting the time required to lift up the toilet seat 2 based on a user habit, and a cover 83 which is integral to the absorption portion 76 and is selectively engaged to the air discharge hole 82 for thereby covering the air discharge hole 82.

The operation of the automatic opening apparatus of the toilet seat according to a fifth embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in Figure 11, in a state that the toilet seat 2 maintains an initial state that the toilet seat 2 is lifted up toward the water tank 5 by the weight of the weight 75 when a user uses the toilet system, as the toilet seat 2 is rotated in the direction of the toilet bowl 1 about the hinge shaft 72 as a center shaft, the weight 75 is rotated in the counterclockwise direction indicated by the full line in Figure 11.

At this time, as the user pressurizes the toilet seat 2 by his hip, the air absorption plate 77 formed in the bottom of the toilet seat 2 is absorbed on the upper surface of the toilet bowl 1, so that the toilet seat 2 is temporarily absorbed

on the upper surface of the rim of the toilet bowl 1.

Therefore, in the case that the user stands up from the toilet seat 2 after use, since the toilet seat 2 maintains a state that the toilet seat 2 is attached to the toilet bowl 1 for a certain time period (for example, 10-20 seconds) set by the air absorption plate 77, the toilet seat 2 is instantly rotated to its initial position by the weight 75 when flushing after use for thereby preventing any interference.

In detail, when the user stands up from the toilet seat 2 after use, as an external air is introduced through the air discharge groove 80 formed in an outer circumference of the threaded portion 80 of the air amount adjusting portion 81 engaged to the threaded hole 79 formed in the fixing portion 78 of the air absorption plate 77, the toilet seat 2 is automatically returned to the initial position after a certain set time passed based on the rotation of the weight 75 when an absorbing force of the air absorption plate 77 is decreased.

At this time, it is possible to adjust the speed that the toilet seat 2 is lifted up by detachably engaging the assistant weight 74 based on the age, sex, and health state of a user who uses the toilet system and a certain environmental factor such as an installation place of the toilet bowl 1. In addition, it is possible to fine adjust the speed that the toilet seat 2 is lifted up by the cover 83 which is selectively engaged to the air discharging hole 82 formed in the absorption portion

76 of the air absorption plate 77, so that a patient or an elder may use conveniently.

Sixth embodiment As shown in Figures 12 and 13, the automatic opening apparatus of a toilet seat according to a sixth embodiment of the present invention includes : A toilet seat 2 which is rotatable in an upward and downward direction and is integrally fixed to the hinge shaft 72 rotatably hinged by a pair of support plates 70 and 71 fixed to a rear side of an upper surface of a ceramic toilet bowl 1 and is formed in an elliptical shape and has an opened center for thereby covering an edge portion of the upper surface of the toilet bowl 1; An elastic member 86 which is installed in an outer side of the hinge shaft 72 and in which one end of the same is fixed to a lower side of the toilet seat 2, and the other end of the same is fixed to a protrusion 85 integrally extended from the support plates 70 and 71 and elastically biases an initial state that the toilet seat 2 is lifted up from the toilet bowl 1; and A delay unit which is installed in one side of a lower surface of the toilet seat 2 and is adapted to prevent any interference when as the user stands up from the toilet seat 2, the toilet seat 2 is instantly lifted up from the toilet bowl 1 by a recovering force of the elastic member 86.

At this time, since the delay unit is the same as the air absorption plate 77 installed in a lower surface of the toilet seat 2 according to the fifth embodiment of the present invention, the descriptions thereof will be omitted.

Seventh embodiment In the automatic opening apparatus of a toilet seat according to a seventh embodiment of the present invention, as a unit for lifting the toilet seat 2 to its initial position when a user stands up from the toilet seat 2, there are provided a pair of compression coil springs 91. One of each of the same is fixed to a lower surface of the toilet seat 2 as an elastic member which elastically biases in an initial state that the toilet seat 2 is lifted up from the toilet bowl 1, and the other end of each of the same is fixed to an upper surface of the protrusion 85 integrally extended from the support plates 70 and 71 which fixedly hinge the toilet sear 2 to the toilet bowl 1.

Therefore, it is possible to decrease the number of parts and a fabrication unit cost.

Eighth embodiment As shown in figures 15 and 16, in the automatic opening apparatus of a toilet seat according to an eighth embodiment of the present invention, as a delay unit capable of preventing the toilet seat 2 from being instantly lifted up from the

toilet bowl 1 after use, there are provided a protrusion plate 88 which is protruded opposite to a lower surface of the toilet seat 2 and has a semi-circular groove 87 formed in the opposite surface, and an engaging plate 89 which is elastically supported by the protrusion 85 and is detachably engaged to the concave groove 87. Therefore, when the user stands up from the toilet seat 2, it is possible to delay the time required for lifting up the toilet seat 2 from the toilet bowl 1 based on a release of the locking force of the engaging plate 89 with respect to the concave groove 87 by an elastic member 90 installed in the protrusion 85 and having a certain elastic force smaller than the weight of the weight 75.

As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described examples are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.